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Previous NEWS |
December 2009
26/12 –Replacement of the joint between the kneecap and the knee
20/12 – Raising numbers of postoperative infections after total hip surgery
18/12 – Inadequate timing of antibiotic prophylactic in total knee surgery
11/12 – Elevated postoperative temperature after total joint surgery – when to care
08/12 – Failure of hip surface replacement by metal allergy - young women are at risk
November 2009
27/11 – Advanced TK model not better than the simple one
15/11 - How long a stem component?
06/11 -Engaged surgeon – an advantage, for who?
October 2009
27/10 – Obese patients benefit from total hip replacement
22/10 – Total hip arthroplasty in patients with neurological conditions –is it feasible
01/10 – Statistics of failures of total hips – when they fail is important, not only how many fail
September 2009
18/09 – Which patients will have good result of a pelvic osteotomy?
12/09/ - Are more complicated designs (mobile bearing) of total knee more successful – no
08/09 – Fulfillment of patient’s expectations for total hip arthroplasty
August 2009
20/08 – two parallel Joint Replacement Registries in the USA ?
18/08 – Scandinavian total hip replacements – what have they common?
11/08 - 70 % of all Birminham resurfacing hip failures have metal allergy as a cause
06/08 – Metal allergy causing failure of surface replacement hips – a cause known 34 years
02/08 – American orthopaedic surgeons announce the creation of the American Joint Registry
July 2009
30/07 – antibiotic prophylaxis before dental treatment – necessary precaution or dangerous abuse
29/07 – skin closure after total hip replacement –which method is best?
24/07 - the painful surface replaced hip
09/07 – Which total hip model for you?
05/07 – osteotomy for treatment of hip osteoarthritis in young patients
June 2009
28/06 - What is your top priority – the best surgeon or the best total joint model?
12/06 Labrum tear – a new disease of young people with hip pain
10/06 – How long will a total knee joint last? – 20 years at least
December 2009
REPLACEMENT OF THE JOINT BETWEEN THE KNEECAP AND THE KNEE
Wearing out of the joint between the kneecap and the knee joint causes severe pain to some patients and poses problem for the surgeon. If it is the only damage of the knee joint what is the best treatment method?
If all previous treatment methods with braces, injections fails and the patient still has severe pain in the front of his/her knee, one contemplates a replacement operation, Such operations were carried out in the 1970’s with little success, so this replacement surgery was abandoned. In patients with severe complaints some surgeons carried out replacement of the whole knee joint surfaces. With success.
This, however, was to offer too much of the yet healthy knee joint to treat a damage of a little part of it, Thus, some surgeons returned to replace only this smaller part of knee joint – the femoropatellar joint with a newly constructed replacement device.
This picture shows A) the modern replacement device (Avon, Stryker). The photography shows the shining upside to the left and the gray backside, There is also a polyethylene component for replacement of the patellar (kneecap) surface.
B) Operation photo shows the device in place in the middle of the knee joint- between both femoral condyles.
The British surgeons published recently a short follow up information about the results of 29 patients with 37 knees replaced with such a modern patellofemoral replacement (Starks 09).
All but one patient were satisfied. Two patient needed revision operation; one, because the replaced patella fractured, the other one because at the primary operation the surgeon did not replace the patellar surface. Both patients were satisfied after the second surgery.
Aftyer two years the functional outcome of the knee improved. Only one patient showed signs (on x-ray pictures) that the osteoarthritis (wear out) progressed longer out into inner part of the knee joint, yet without causing complaints.
Information to you: If you have severe pain in your femoropatellar joint, this new replacement surgery is promising. The results are, however, only covering two years postoperative.
References
Starks L et al: The Avon femoropatellar joint replacement. J Bone Joint Surg-Br 2009; 91-B: 1579 – 86.
RAISING NUMBERS OF POSTOPERATIVE INFECTIONS AFTER TOTAL HIP SURGERY
Postoperative infection is probably the most serious complication of total hip replacement (THR). Since its introduction in 1960’s surgeons strived to keep postoperative infection after THR at lowest level – from the initially 6 -10% to the 0.5% in the early 2000’s. In Scandinavia, however, there appear disquieting reports that the postoperative infections after THR are on the rise.
The recent report from the Norwegian Arthroplasty registers reports that the risk of postoperative infection increased three rimes (!) for the THR operated on between the periods 1987-1992 and 2003 – 2007. The patient group at highest risk for postoperative infection were the patients operated on with uncemented THR, whose risk increased five times (!) between 1987-1992 and 2003 – 2007.
The important question is what caused the increase of this risk in Norway? Especially as reports from other countries do not find such increase.
The authors themselves made a very careful evaluation of all possible factors influencing the frequency of postoperative infections and found some possible factors that might explain this rise of risk for postoperative infection.
The hygienic routines, the overcrowded departments where the patients with replaced hip joints are placed, the inadequate routines for application of prophylactic antibiotics were well documented for many Scandinavian hospitals. Moreover, the incidence of postoperative infection varied between 0.0 and 2.8 % in individual hospitals.
Then there are some more theoretical risk factors, such as emergence of very virulent bacteria causing these “new” infections. However, such bacterial strains vere as yet not documented.
Information for you:
This report is an excellent proof that you should choose the hospital for your future total hip replacement with care. Right hospital and right surgeon have precedence before the total hip prosthesis that you have chosen personally. Then it is a question if the downfall of hygienic routines as observed generally in some Scandinavian hospitals is also occurring in other countries.
Rferences
Dale H. et al.: Increased risk of revision due to deep infection after hip arthroplasty. Acta Orthop 2009; 80: 639 - 45
INADEQUATE TIMING OF ANTIBIOTIC PROPHYLAXIS IN TOTAL KNEE SURGERY.
Antibiotic prophylaxis is the most important factor that alone diminish the risk of postoperative infection after total hip and knee surgery with 80%. To work well, the antibiotics must be in blood in sufficient concentration when the surgeon makes his first incision and stay there until the wound is sutured.
In total knee surgery enters an important factor. The operation is done on the blood free limb. The inflated tourniquet keeps all circulation stopped under the surgery.
The TK patients thus must receive the antibiotics 15 – 45 minutes before the tourniquet is inflated to have real antibiotic prophylaxis of their TK surgery.
If the injection with antibiotics is done earlier, the antibiotic disappears from the circulation, if it is done later on, the antibiotic has not enough time to saturate the tissues of the limb.
The Swedish surgeons studied how well is this practice of administration of antibiotics just in time followed of in Sweden.
On patients selected randomly from the Swedish Knee Register they extracted the times before the surgery when the patient get his / her antibiotic prophylaxis (intravenously or as an intramuscular injection.
It appeared that 51% of all patients operated on with TKR did not get the prophylaxis in time. Unfortunately, the group of studied patients was too small (405 THR operations) to study if the untimely administration of prophylactic antibiotics caused any increase of postoperative infection. In every case the authors did not study this important question.
Information for you:
A study that does not answer the right question: Does the bad routine of administration of prophylactic antibiotics increase the rate of postoperative infections? But the study is important because it demonstrates that the routine on Scandinavian hospitals are successively corroding.
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References
Stefansdottir A et al.: Inadequate timeing of antibiotic prophylaxis...Acta Orthop 2009, 80: 633 - 8
ELEVATER POSTOPERATIVE CARE AFTER TOTAL JOINT SURGERY – WHEN TO CARE
Elevated temperature after total hip and total knee surgery is common, it is carefully notated in patient’s journal, yet its characteristic development is seldom studied.
A group of Taiwan surgeons published recently a statistics on postoperative temperature trends in 186 patients who healed without complications after total knee replacement surgery (Tai 2009).
This diagram shows the mean daily maximal temperature from the operation day (Day 0) through to the fifth (Day 5) postoperative day in 186 patients who healed without any complication after an uncomplicated TK arthroplasty.
It appears that the highest mean postoperative temperature (37.7 dgr C)
occurs on the first postoperative day to climb down to normal (< 37.5 C) on the fourth postoperative day.
However, the temperature elevation > 38.0 dgr C occurred more seldom, usually during the second and third postoperative day and dropped quickly to normal (< 37.5 degr. C). The elevated temperature very seldom reached 39.0 degr. C.
This diagram shows the percentage of patients who had temperature >= 38.0 dgr C on the successive postoperative days 1 to 5. Day 0 is the operation day.
It appears that 10% of all patients had elevated temperature => 38.0 C already on the operation day.
On the other hand and more important, only just 5% of all “normal” patients had still temperature => 38.0 C on the fifth postoperative day.
The elevation of postoperative temperature is caused by the operative trauma. One possible mechanism is the release of inflammatory factors, such as necrosis (IL-6) factors and like. Another potential cause of elevated temperature is the decreased hemoglobin level and / or transfusion of blood products.
Surgeons follow the postoperative temperature because its elevation may herald the start an early postoperative infection, the most dreaded early postoperative complication. Patients with early postoperative infection, however, tend to have more prolonged and higher fever that usually occurs later on, on 4 and 5th postoperative day and even later.
Other causes of postoperative fever, that occurs later on, may be deep vein thrombosis, incipient ossification of soft tissues (Heterotopic ossifications), lung atelectasis (badly ventilated lung tissue), and urinary tract infections.
Information for you:
Obviously elevated temperature after total knee (and total hip, Summersell 2003) replacement is common and has typical pattern. If your elevated temperature shows this pattern (Highest on second & third postoperative day and then down on about fifth day), then there is no cause to panic and start expensive and extensive testing.
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References:
Tai TW et al.: Elevated temperature trends after total knee arthroplasty. Ortopaedics 2009; 32: 886
Summersell PC et al.: Temperature trends in total hip arthroplasty. J.Arthroplasty 2003; 18: 426-9
FAILURE OF HIP SURFACE REPLACEMENT BY METAL ALLERGY – YOUNG WOMEN ARE AT RISK
The hip surface replacement is a replacement surgery suited especially for young people. Yet, according to two recent reports of British surgeons the young patients are at especially high risk for the newly discovered complication, so called inflammatory pseudotumour (Glyn-Jones 2009, Hart 2009).
The pseudotumours are masses of solid or cystic soft tissue arising around the surface replacement devices. They contain also much fluid. Successively they destruct the skeleton to which the devices are fixed. The patient feels usually increasing pain in the groin, but smaller pseudotumours may grow unnoticed by the patient.
Probably these pseudotumours are elicited by a local allergic reaction in the patient’s soft tissue around against the surface prosthesis the metallic wear particles that are loaded there. It was shown that patients with these pseudotumours have high load of metallic wear particles (metallosis) in the tissues around the prosthesis. On the other hand, not all these patients have general signs of metal allergy (in blood tests).It thus seems that these pseudotumours in most patients are a local reaction only on the presence of metal.
At high risk for this complication are young patients (< 40 years) especially young women < 40 years of age. Other factors are interdependent (small cup, congenital hip dysplasia).
At eight years postoperatively, only 0,5% of male patients’ surface replacements failed because of the inflammatory pseudotumour whereas the failure rate was 6% for women > 40 years of age and 13% for women <40 years of age respectively.
One possible explanation of this strongly gender related complication is a latent metal allergy, present in women due to their use of metallic jewelry.
Information for you: these British figures are serious enough. Young women should consider this staistics carefully when they contemplate a future surface hip replacement. It is interesting that these figures are coming mainly from Great Britain, whereas these complications are scarce on the other side of the Atlantic. Lack of statistics? Or are the New World’s women resistant against local metal allergy?
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References:
Glyn-Jones G. et al: Risk factors of inflammatory pseudotumour formation…J Bone Joint Surg-Br 2009; 91-B: 1566 – 74.
Hart AJ. Et al.: The painful netal-on-metal resurfacing. J Bone Joint Surg-Br 2009; 91-B: 738- – 44.
November 2009
ADVANCED TK MODEL NOT BETTER THAN THE SIMPLE ONE
The engineers constructing artificial knee joints have always had problems with the non conformity of the bearing surfaces. Read please more about the problem and see the pictures in the chapter Mobile bearing total knee.
The definite solution of this problem at present is the mobile bearing total knee design. This total knee joint model should have much less wear, better motion, and better function. But also a much higher cost.
There were published many studies about the performance of this total knee model, some of them showed better results for the new model, other studies did not find any difference between the old cheap all-polyethylene models and the new expensive mobile bearing model.
Recently, a group of American surgeons published a thoroughly planned study where they compared the performance of these two models (Gioe 2009). The study is 8 pages long, the most space takes the description how the study was planned. The authors really came long in excluding all possible factors (gender, age, disease) that could bias the results. So if any difference was found between the results of the two total knee models (designs) the difference would be caused by the innate characteristics of the respective model.
After a mean of forty two months of observation, the authors did not find any difference between the function of both models. The range of motion, the function scores, the x-ray measurements of the model’s position were very similar. The postoperative complications were equally distributed in both groups..
No component failed because of wear of polyethylene or loosening in either group. Measurement of polyethylene wear of the tibial component was not done, it is difficult and unreliable.
Information for you: This study supports the conclusion of many similar studies. The only difference between the older all-polyethylene total knee designs and the newest mobile bearing total knee designs is the price.
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References:
Gioe TJ et al: Mobile and fixed bearing (all-polyethylene tibial component) total knee arthroplasty design. J Bone Jt Surg-Am 2009;91-A: 2104- 12
DEATH OF BONE TISSUE AROUND SOME SURFACE HIPS – IS THE BAD PLACEMENT AND CONSTRUCTION OF THE DEVICE THE CAUSE?
English surgeons, who developed the surface hip replacement, continue to be troubled by the unexpected complication of these metallic hip resurfacing devices: the death of the tissues around the some surface hip replacements.
The cause of this tissue death is the hic concentration of metallic ions, mainly cobalt and chrome, around the surface replacement device.
New facts are emerging. The high wear of small metallic particles depends not only on the placement of the device, so called edge loading. It depends also on other factors, such as the size of the device, construction of the device and some characteristics of the metal used for the manufacture of the surface hip device.
Recent publication shows that 7 % of surface hip replacements develop the necrosis (death) of soft tissues around the new surface hip replacement model ASR (Articular Surface Replacement, DePuy) within 5 postoperative years (Langton 2009).
Again, we see here that an “armchair” idea is excellent just in the armchair environment, but has drawbacks when introduced in praxis. Why has ASR so many failures?
In the 1960’s when the first metal-on-metal (McKee-Farrar) total hips competed with Charnley’s metal-on- polyethylene total hips, John Charnley’s argument against the competing metal-on-metal total hips was just that the metal-on-metal hips have very high friction. Right, because the space (clearance) between the bearing surfaces of these old metal-on-metal total hips was uneven and too large. This caused edge wear as seen on the upper row of this picture
Modern surface hips have very small clearance between bearing surfaces (nominally about 0.1 mm in Birmingham hip, Stockton b 2009) which produces a good lubrication when the surfaces are moving and good clinical results.
In the quest to achieve even better lubrication of bearing surfaces, the engineers at DePuy produced their ASR surface hip with clearance of only 0,05 mm. This “improvement” had unexpected consequences. The wear of the ASR is substantially greater than the wear of Birmingham Hip (Langton b 2009).
Moreover, the wear depends not only on the position of the device but also on its size. Too large surface replacement devices have increased wear, even if placed correctly. And with exaggerated wear comes large concentration of metallic ions around the device and then death of the tissues.
Information for you: Again, these data show that surface hip replacement is a successful only in carefully selected patients. And we can add: with carefully chosen implant.
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References:
Langton DJ et al: The incidence of adverse reactions to metal debris following hip resurfacing…Presented at The British Orthopaedic Association’s Annual Congress 2009, Sept 16 -19th, Manchester
Langton b DJ et al: Blood metal ion concentration…. JBone Joint Surg-B 2009; 91-B, 1287- 95
HOW LONG A STEM COMPONENT?
The fixation of the femoral component of a total hip has always been a problem. To replace only a surface of the femoral head was not feasible – the precarious vascular nourishment and the anatomical structure of the femoral head make placement of a simple cup over the denuded surface of the femoral head impossible. A stem was always necessary to fix the new head to the thighbone.
See also the chapter Surface hip replacements.
In the beginning the surgeons generously removed big parts of the thighbone’s skeleton (its upper part) to make place for generous stem components that occupied the upper part of the femoral marrow cavity. In the old people who made the majority of these patients the skeleton’s offering did not matter.
Today, however, every centimeter of spared skeleton in the young patients is important.
Today the surgeons thus are churning out new models of femoral components that would remove only the smallest parts of the damaged femoral head and use the shortest shaft component to fix the whole component to the thigh bone.
In this advertising picture for such new model (The Birmingham Mid Head Resection prosthesis, Smith&Nephew), the manufacturer, however, left out an important category of the true “short stem femoral components”.
Common for these latter models is a shaft shorter than the conventional shaft component of the total hip model. The length of the shafts in these models varies:
In some (Thrust prosthesis) the shaft goes through the whole length of the femoral (thighbone’s) neck but doesn’t engage the upper part of the thighbone’s marrow cavity.
In others (Mayo Conservative Hip) the shaft engages also the upper part of thighbone.
From this picture of the Mayo Prosthesis it is obvious that the short stem component reposes on the rest of the femoral collum. Its length is “conservative” as the name says. The end of the stem then thrusts on the hard corticalis bone of the femoral shaft. It is obvious that the Mayo Hip engages the upper part. On the other hand, the stem although shorter than the conventional stem, still engages rather large part of the upper thigh’s bone marrow.
The Birmingham Mid Head Resection is a changeover from a surface replacement hip model to a model with short stem. Whereas in the surface replacement arthroplasty the surgeon will only chamfer the upper damaged surface of the femoral head, in Mid Head Resection the surgeon will resect (remove) about a half of the femoral head and replace it with a much more massive metallic half sphere.
The results of the operation with surface replacement are now published for periods longer than 5 years. These results are good, 95 % of these hips survive5 years in carefully selected patients.
Also the results of short stem femoral components are known and are good: for example 98 % of Mayo Conservative Hip components survived 10 years (Mayo Conservative Hip 2000).
But for the newest Birmingham Mid Head Resection, I could not find any reliable data published.
Information for you: For carefully selected patients operated on by carefully elected surgeons the future is bright. The new types of total and surface hip replacement are appearing on the market and for some of them there are even published very good results.
References:
Kluge W.: Current developments in short stem femoral implants. Orthopaedics and Trauma 2009; 23: 46-51
Mayo Conservative Hip: J Bone Joint Surg-Br 2000, 82-B, 962-8
ENGAGED SURGEON - AN ADVANTAGE, FOR WHO?
Surgeons always developed special tools that made more audacious operations possible. Many such tools bear the names of these inventive surgeons.
Pean is a tool used daily in operations over the whole world. It is a tool to grasp, compress, and hold soft tissue.
It has also many forms for more specific purposes.
On this picture is a pean that is used as a haemostatic forceps, to stop bleeding from a larger vessel. The surgeon grasps and compresses the bleeding vessel with the long elastic blades of the pean.
Doctor Jules Pean operating on a patient’s mouth. This is a picture by the well known French impressionistic artist Toulouse-Lautrec painted in 1891.
Doctor Pean keeps in his right hand the forceps that bears his name today. Not much is known about the origin of this picture
Not many present day surgeons recognize the historical personality of a 19th century French surgeon Jules Pean behind the haemostatic forceps pean, which is used daily in all surgical operations. These tools were often manufactured by small but dedicated manufacturers in very small series and initially it was the surgeon who paid the manufacturer for the product. There were no ethical questions as to the surgeons’ economical gain from their tools. (See also the chapter Prehistory of Total Joints).
The economical situation radically changed in the 1960 – 80’s with the emergence of “the medico-industrial complexes”. The term is Professor Sarmiento’s, an USA’s orthopaedic surgeon with radical opinions and some patents on titanium made total hip joints.
When total joints, mainly total hips and total knees, entered the competitive market, the manufacturers recognized that to stay on this market they must produce a steady stream of new models of total joints.
Preferentially, more than one material shall be used in production of the total joint, as shown on this total hip model, whose bearing surfaces are made from, successively: metal & metal, ceramic & ceramic, and metal & polyethylene.
(MYSIS total hip system, Mathys Orthopaedics Ltd)
Every new model shall preferably have any change in its form, large or small, as is shown on the succession of shaft components for a total hip. Even if some changes are small, every model has a proprietary name (ANTHOLOGY total hip system, Smith & Nephew)
Every new total joint model shall have a set of new tools for easier operations. But above all, there should be a cadre of dedicated surgeons available who will teach other surgeons how to operate these new models on the growing numbers of patients.
The manufacturers also recognized that to gain the collaboration of the busy surgeons they must pay them well. The USA Government investigation discovered that in 2007 five major orthopaedic device manufacturers paid $311 million to the collaborating surgeons.
This investigation also found that “most payments to doctors were for legitimate services, but alleged that in certain cases companies received little value or only minimal work in return”. To translate this statement in more understandable language, certain doctors were paid just for using company’s products (total hips).
When these payments escalate certain important questions appear: Having been involved in development and paid for it, or only paid, for use of a specific total joint model, the surgeon is likely to use it to treat his patients with. Is this reassuring for the patient or a cause for concern? It should be reassuring, as all doctors have a primary duty of care to their patients, says Doctor Rajaratnamn, Chief Compliance Officer at Smith & Nephew (Rajaratnamn 2009).
One must understand that the patients may be, and some really are, suspicious of that the payment received by the doctors in different forms (royalties, consulting payments) from the manufacturers makes the doctors less decided to use the best total joint for their patients. Some facts support this suspicion.
One is the well publicized fact that the majority ( 75 – 85) of all new total hip models on the market have no documentation of their efficacy. Their use rests on the recommendations made by the doctors employed and paid by the manufacturers of these models.What is worse, the reports from the National Joint Registers demonstrate that the rate of failures of these new total hip models is higher than the failure rate of the old models. (See the report from 01/10/2009.). Thus these doctors are recommending worse, and most often also more expensive, products, although these models do not have a substandard performance.
On the other hand, the governments (and society in general) ceased to finance many areas of medical science and research. Artificial joint science is one of these areas. The industry successively took over the financing of this area of medical science; without industry’s financial support there would be minimal development of new total joints, of new materials for their manufacture, but most importantly, there would not be sufficient many teachers to teach other surgeons how to operate on total joints. No wonder, that industry provides these services on its own conditions, and that industry also pays the surgeons for this service.
What is the conclusion from these facts for you, the patient?
It would be nice if you can come with your own conclusion!
References:
Rajaratnam A.: Current trends in the relationship between orthopaedic surgeons and industry. J Bone Joint Surg-Br 2009; 91-B: 1265 -6
October 2009
TOTAL HIP ARTHROPLASTY IN PATIENTS WITH NEUROLOGICAL CONDITIONS – IS IT FEASIBLE?
Patients with neurological conditions were usually denied the possibility of total hip replacement because of the fear that the worse muscle control of the new artificial hip would lead to its dislocation.
Sometimes THR were done in specialized hospitals on these patients but the results were not generally known.
Irish orthopaedic surgeons published recently an overview of published results of THR done on patients with neurological conditions (Queally 2009)
Patients with cerebral palsy, poliomyelitis, Parkinson’s disease, and suites of cerebrovascular accident were successfully operated on with THR.
The conditions, under which such a replacement is feasible, however, vary. The surgeon must consider the abnormal muscle tone and weakness caused by paresis, muscle contractures, and tremors. All these changes cause muscle imbalance that increase the risk of dislocations and loosening of the implanted total hip joint.
Nonetheless, THR can be successful in carefully selected patients with neurological condition relieving them from the constant pain. Postoperative instability / dislocation is the main complication.
Information for you: It may be valuable just to know that you might benefit from THR even if you have some of the named neurological conditions. This is an operation to be done by experienced surgeon at a specialized institution.
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References:
Queally J.M. et al.: Total hip replacement in patients with neurological conditions. J Bone Joint Surg-Br 2009; 91-B: 1267 – 73
OBESE PATIENTS BENEFIT FROM TOTAL HIP REPLACEMENT
Some surgeons advise obese patients against total hip replacement. There is, however, pouring in new evidence that the obese patients have equally good pain relief and satisfaction from the THR as their lean colleagues.
The last of such evidence is the report from Australian surgeons on the results of 2026 THR replacements (414 of the done in obese patients) done on 1659 patients (358 of them obese).
The obesity was defined as the BMI >30 (See also Obesity details)
These patients were followed up for 10 years
Some important conclusions from this report: The relief of pain and the degree of satisfaction with the surgery wes equally great in both patient groups, obese and lean patients.
During the ten years of follow up the mechanical loosening of the implanted cementless total hip was equally frequent in the obese and the lean payient group. Explanation: the obese patients move less and put less weight on the new hip. Moreover, the fett cells produce a special hormone, leptin, that keeps the skeleton strong.
The postoperative complication rate (infections, dislocations) was equally heigh in both patient groups.
The function (range of motion, muscle force) was considerably worse in the obese patients group compared with the lean patients.
Information for you:
You may have a good result of pain relief of your total hip surgery even if you are obese. But the function in your new hip will improve not so much.
References:
Jackson MP et al.: The effect of obesity on the midterm survival… J Bone Joint Surg-Br 2009; 91-B, 1296 - 1300
STATISTICS OF FAILURES OF TOTAL HIPS – WHEN THEY FAIL IS IMPORTANT, NOT ONLY HOW MANY THEY FAIL
Several reports pointed to the fact that the majority of the total hip models on the market have no proven record that will show how successful just this model is in the longer follow-up.
Here the National Hip Registers have a given role to provide statistics about the efficiency of all these “new and improved” models of total hip joints.
The surgeons and statisticians from the Norwegian Arthroplasty Register just published such a report (Espehaug 2009).
Also in Norway the surgeons observed that “several of the (total hip) prostheses in common use today have insufficient clinical documentation of clinical quality, or lack it altogether.”
The authors compared the survival of the ten most used prosthesis models as reported to the Norwegian Arthroplasty Register during the years 1987 (when the Register started) to 2007. As 75 % of total hips in Norway have been attached with bone cement to the skeleton, the authors studied only cemented total hip models.
It appeared that there were clinically important differences between different total hips models. Many of the commonly used new total hip models (Reflection All-Poly/Spectron-EF) have inferior results compared with the old total hip models (Charnley). Even the badly performing total hip models, however, had better survival rates then international benchmarks demand.
The authors of this report noticed that the risk of total hip failure changed during a longer follow-up. This is an important observation, a genuine “first time”! As yet, the surgeons did not bother about the changing risk of failure of total hips during longer follow-up periods.
But to know when the risk for failure of a total hip increases is important both for the surgeon and for the patient. The surgeon can put extra control visits for the patient during this period; the patient might have some extra precautions ordered.
What the surgeons today wish to know is the total percentage (correct statistical term is “cumulative probability of survival”) of survived total hips at the end of the follow-up interval. That is the only measure that the total joint industry uses in marketing their products, and it is this industry that finances the majority of these statistic studies.
Some simplified diagrams from the published paper will explain this problem.
All man made things decay successively with time. The total hip prostheses make no exception. The survival curve depicts nicely how the numbers of still intact total joints diminish successively during the postoperative follow up.
This diagram shows two survival curves: the black one is the survival curve for the “classic” Charnley total hip model, the red one is for the modern total hip model. “Only” 97 % of the Charnleys total hips survived 5 year of follow up, whereas impressive 99 % of modern total hips survived the same interval.
The visual impression of the difference in the slopes of the survival curves is clear – the “classic” Charnley model sinks quickly down, whereas the modern total hip model floats evenly – an impressive selling argument for the modern total hip model.
This picture of supremacy of the modern total hip model changes dramatically when one follows the survival for twenty years (what the Norwegian surgeons did.
This diagram shows that the failures of the modern total hip accelerate progressively during the whole follow (the slope of the red curve increases progressively), whereas the rate of failures of the classic total hip remain unchanged (the red curve is almost a straight lline). The net result of this change is that “only” 84 % of modern total hips survived 20 years, whereas “whole” 88 % of classic Charnley total hips succeeded with it.
The next figure demonstrates the increasing risk of failure of the modern total hip model with follow up time:
The diagram shows that the risk of failure of failure of the modern total hip during the first five postoperative years was only one third (0.3) as high as the risk of failure of the Charnley’s total hip. In the period from 6 to ten postoperative years the risk of failure of the modern total hip was still lower than the risk of failure of Charnleys total hip, although the difference diminished to 0.8. During the 11 to 20 years after the operation the situation reverted: the risk of failure of the modern total hip was almost twice as high (1.7) as the risk of failure of the Charnley’s total hip.
Information for you:
When you read about the wonderful results of a new model of total hip, look how long was the follow-up time. Patients with short follow up time must have low failure rates – they were at risk only a short time. With longer period of follow-up the failure rate increases but then the total hip model is no longer “a new one”.
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References:
Espehaug B. et al: 18 years of results with cemented primary hip prostheses…. Acta Orthopedica 2009; 80: 402 -12
September 2009
FULFILLMENT OF PATIENTS’ EXPECTATIONS FOR TOTAL HIP ARTHROPLASTY
Patients have multiple expectations for total hip arthroplasty (see also the chapter Expectations and Satisfactions), expecting disappearance of the pain and improvement of the function in the new hip joint. It was also demonstrated that not fulfillment of expectations influences patient’s satisfaction with the replacement surgery, although less profoundly than expected
Doctor Mancuso and colleagues from the New York Hospital For Special Surgery had studied this question extensively.
In the last report she demonstrates that total hip replacement surgery is first and foremost pain surgery, whereas restoration of the joint function is less predictable Mancuso 2009).
Patients who mainly expected disappearance of pain were satisfied in > 90% of cases, irrespective of whether the preoperative pain was very severe or only mild.
On the other hand, the expectations of return of function in the new hip were better fulfilled in patients whose “natural” hip joints had better function already before the surgery.
Preoperative limp was difficult to eradicate. Persisting limp after surgery was the main source of patients’ dissatisfaction.
Information for you: It is sensible to expect considerable mitigation / total disappearance of pain after total hip replacement irrespective of how much pain you suffered before the surgery.
On the other hand, don’t expect full return of function in the new total hip if there was severe limitation of function (limp) already before surgery.
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Reference:
Mancuso CA et al.: Fulfillment of patients’ expectations…J.Bone Joint Surg-Am 2009; 91-A, 2073 - 8
ARE MORE COMPLICATED DESIGNS (MOBILE BEARINGS? OF TOTAL KNEE MORE SUCCESSFUL – NO
Designers of the total knee joints are trying to develop total knee models more like the “natural” knee joint. Such models would have low wear, low stresses on the joint surfaces and thus less failures.
One such model is the so called mobile bearing total knee (see also the chapter Mobile bearing total knee). Besides theoretic predictions that mobile bearing total knee model would have low wear it was also predicted that it would be easier to place in the patients knee joint and allow better range of motion of the new knee joint. One obvious disadvantage was the complicated construction which caused dislocation of the mobile part and higher cost.
The simple model of total knee (so called fixed bearing model) has theoretically greater stresses on fixed joint surfaces and it was predicted that it thus would have more failures compared with the mobile bearing model.
These theoretical predictions, however, did not realize. Recent large study from the Veteran Administration Hospital, Minneapolis, Minn., USA demonstrates that except for greater financial costs, the results of fixed and mobile bearing total knee models (Sigma RP, DePuy) are practically equal (Gioe 2009).
Information for you: This is an important study, because it is well designed and conducted. Thus, the results are credible. You can have equally good result after replacement with a simple, cheaper total knee model, as with much more expensive design. Just pick a good surgeon for your surgery.
Reference:
Gioe TJ et al: Mobile and Fixed Bearing total knee… J Bone Joint Surg-Am 2009 ; 91-A: 2104 -12
WHICH PATIENTS WILL HAVE GOOD RESULTS WITH A PELVIC OSTEOTOMY
Hip dysplasia (see Hip joint diseases) in young patients produces incongruity in the joint surface of the hip joint that usually leads to premature destruction of joint cartilage and development of joint osteoarthritis. These patients then may need an early total hip replacement to cure the pain and functional defects of the hip joint.
An operation that will restore the congruity will also prevent development of osteoarthritis of the hip in these patients and thus make the premature total hip replacement not necessary. Such operation is called pelvic osteotomy (see the chapter Alternative hip joint operations.)
Which patients will benefit from this operation?
Recently, surgeons at the Children Hospital, Boston, Mass, USA studied 187 such osteotomy operations done in 157 patients. Ten years after the osteotomy 84 % of all patients were still painfree.
The patients with the failed operation were usually > 30 years old, and have often already much deformed joint surfaces.
Information for you:
The best candidates for the pelvic osteotomy are patients < 30 years old, with still well preserved surfaces of the hip joint
References:
Matheney T. et al: Intermediate to long term results following the Bernese periacetabular osteotomy… J Bone Joint Surg-A, 2009; 91-A: 2113- 23
August 2009
TWO PARALLEL JOINT REPLACEMENT REGISTRIES IN THE USA?
Two Democratic senators supplied a bill to the U.S. House of Representatives to establish a national hip and knee joint replacement registry
“It is outrageous that medical devices (total joints) are being made available in America that are so lousy they have been withdrawn in markets overseas. As Congress seeks … to reduce health care costs, bringing higher standards to the medical device industry would be a good place to start” said one of the co-sponsors of the bill Repr. Bill Pascrell.
Not a bad goal for a total joint replacement registry, also with the view that about a half of all total joint replacements, one million of total hip and total knee surgeries carried out annually worldwide, is done in the USA. The sponsors of this bill have the “successful UK national joint registry” as a prototype. They believe that the registry will not only reduce the increasing rates of costly revision operations, it will also provide the patients with information to choose the best performing device.
At the same time it will educate the surgeons demonstrating for them which total joint model to choose for operation of a certain patient category. And it would also influence the manufacturers decision which total joint models to introduce on the market and which to withdraw much sooner than today.
American surgeons reacted in two ways on this news that was in preparation since summer 2008. One way, they decided eventually to establish a commercial organization that will successively begin to collect the data about the total joint replacements done in the USA. Probably it will begin its work somewhere in the 2010.
But the American surgeons were also disquieted. They sent a letter to the Committee expressing the concern about the “challenges of data collection and interpretation” in a future joint register. These challenges, according to the letter, are best managed by a private organization.
One of the American leading orthopaedic and replacement surgeons, Thomas P. Schmalzried, MD, stated in an interview that it is an “oversimplification to state that the device fails”, obviously pointing to one of the goals of the proposed joint register to keep a statistics over failures of total joints. And he continued “Total joint devices today rarely suffer a gross material failure”. It is true, the term “failure of the total joint” has many meanings and mechanic disintegration of a total joint device is only one of them. Playing with words?
The Repr Pascrell reacted saying “I am pleased that the orthopaedic surgeons recognize a need to monitor the products they use to do their work, but I am doubtful they will be able to collect the level of data called for in my legislation”
Information for you:
The present bill has been referred to the Committee in the Senate. This is the routine way how such bills are treated. One must also say that the majority of bills submitted to different Committees never make it out of the committees.
Moreover, The British National total Joint Registry is all but a good example to follow for the USA’s politicians. There are the American surgeons right saying that “Collecting the data is a good start, but the critical task is the interpretation of the data”
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Reference:
Orthopaedic Product News /European Edition; July 2009, page 11
SCANDINAVIAN TOTAL HIP REPLACEMENTS –WHAT HAVE THEY COMMON?
The Scandinavian countries Denmark, Sweden, Finland, and Norway have similar health care systems, the doctors and other health care personal in these countries can freely cross the borders in searching the jobs. Every country also had a long tradition of National Hip Registries.
Not to wonder that surgeons in these countries were interested to compare their results of total hip surgery, the comparison to be based on the data registered in the National Registries. In the process, the Finish Registry “decided not to participate due to the changes in their staff” so only the surgeons from Denmark, Sweden, and Norway conducted the study (Havelin 2009).
The first surprise was that the “the databases in the three registers “were not fully compatible”. In fact, definition of individual failures differed in the individual databases, so it was obvious that the comparison of the results could not be too comprehensive. Also characteristics of patients and their diseases differed, so the analysis of the factors leading to the failure could neither go too deep.
So what revealed the published study?
The Danish surgeons used much more uncemented total hip models than their Swedish and Norwegian colleagues (27% vs.14 % and 13 %, respectively). And Danish surgeons preferred posterior operative approach compared with their Swedish and Norwegian colleagues (91% vs. 60% and 24%, respectively).
The revision operations for dislocation of the total hip were done more often in Denmark (34%) than in Sweden and Norway (23% and 24 %) respectively. These figures would indicate that the posterior approach to the hip is associated with higher risk of dislocation, as is maintained in several other studies.
The large material in the databases would invite to closer study, but nothing such is presented.
Then the authors present dutifully survival figures and the survival curves: All total hip models taken together have better chance to survive 10 years in Sweden than in the other two Nordic countries (93,9% vs. 92% in Denmark and 92.7% in Norway), the differences are really small.
Nice figures for all three countries, however, high over the international benchmark (10%).
It appeared that cemented total hips had better ten years survival in all three countries compared with the uncemented models. You may ask whether this difference was caused by the fact that the uncemented models were used predominantly in a certain category of patients prone more often to failure. Again, no close analysis is presented, incompatible databases?
The younger patients (<60 years) in all three countries had more failures than the older patients (>=60). Nice colored survival curves should convince you, but no closer analysis is presented. You may ask whether the risk of failure is higher for these patients during the whole postoperative period, or if it changes as time goes.
Information for you:
I have very uneasy feeling in presenting this study for you. But I decided to present it because the study clearly shows the problems with the national total joint databases around the world. They are incompatible with each other!
For some years Sweden excelled with its results of total hip surgery on international scene. The Swedish surgeons defined a new measure of failure, the so called revision burden. On international meetings the Swedish surgeons then presented the Swedish “revision burden” figures, that were the lowest out of all countries with statistics over total hip surgery.
In the present report the term “revision burden” has been silently put into grave, there is no consensus on definition of the term. Survival figures would suffice according to this report. So it was with the Swedish excellence.
But the results presented in this study are still impressive; you have higher than 95 % chances to go on your artificial hip joint ten years after total hip operation done in any of these Nordic countries.
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Reference:
Havelin L et al.: The Nordic arthroplasty register association. Acta Orthoped 2009 ; 80: 393 -41
70% OF ALL BIRMINGHAM RESURFACING HIP FAILURES HAVE METAL ALLERGY AS A CAUSE
British surgeons at Norwich & Norfolk University Hospitals decided to study how frequent are the early failures of the Birmingham surface hip replacement, at present the most frequently used surface hip replacement system in England.
They studied 463 Birminham surface hip operated on patients for a mean of 43 months (Ollivere 2009).
It appeared that 4 % of all Birmingham hips failed within five years, 70 % of them failed because of allergy to the metals that wear from the surfaces of the artificial surface hips.
The authors, however, do not speak about allergy or immunity reactions, they use curious terms such as “metal debris disease”, “metallosis associated failure”, and “metallosis associated necrosis”.
Signs of this metal allergy complication are sudden pain in the hip area without previous trauma and without blood tests positive for infection. X-ray pictures usually show not much, but MRI reveals soft tissue masses and accumulation of liquid around the diseased joint.
The authors found that women, obese patients, and patients with incorrectly placed replacement device are at risk for this complication.
This is a report that concisely describes the signs and symptoms of this “potentially catastrophic complication” and the authors should be commended for it.
Information for you: If you belong to any of these risk categories stay away from surface hip replacement surgery. The authors of the present study, however, avoid to use the term allergy, instead they speculate whether this “metallosis complication” can be a “reaction to wear debris rather then hypersensitivity reaction”. Obviously, there is no place for testing metal allergy under this perspective.
At the same time in the European dermatology Journals there are appearing papers demonstrating that these “metallosis” patients are allergic against metals in the alloys from whom are produced surface replacement hips. Testing against metal allergy all patients who might be candidates for surface replacement is strongly recommended in these papers.
Already 34 years ago it was demonstrated that metal cobalt is more than twenty times more poisonous to the bone tissue than chrome and nickel. Yet nothing was done to replace the poisonous metal cobalt in the alloys for production of surface replacement devices with anything that the human body will tolerate better.
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Reference:
Ollivere B. et al.: Early clinical failure of the Birmingham metal-on-metal hip resurfacing is associated with metallosis and soft tissue necrosis. J Bone Joint Surg – Br 2009; 91-B : 1025-30
REVISION OPERATION ON FAILED SURFACE REPLACED HIPS OFTEN UNSUCCESSFUL – IN PATIENTS WITH METAL ALLERGY / INFLAMMATORY CHANGES.
The surgeons advocating surface hip replacement surgery have as one of their main arguments that even if “it fails, it is very easy to convert it to an ordinary total hip in a simple operation”.
Surgeons and scientists at the Oxford University, UK, now demonstrated that this assertion is only partly true (Grammatopoulos 2009).
They studied patients with totally 51 surface replaced hips that needed revision operation. 16 surface hips were revised for “pseudotumors”, 21 for fracture of the collum, and 16 for other reasons (infection, instability).
It appeared that a half of revisions done in patients with “pseudotumors” ended with complications, and one third of these patients needed second or third revision operation. The patient satisfaction and function in the revision operated hip were worse than in patients operated on for other complications (fracture of the collum and other complication.
But even the revision operations of the patients with collum fracture were not without problems. 15 % of these operations were further complicated by deep postoperative infection and needed a third revision operation. Then these patients were satisfied (at least they told it to the people who interviewed them!)
Information for you:
The authors of this study do not mention metal allergy, they speak about “inflammatory pseudotumours”. It will probably take a longer time before all surgeons will agree on the cause of these “pseudotumours” and what to do to protect their patients from this complication.
The next article in the Journal uses the term metallosis and suggests allergic reaction to metal wear particles as the cause.
At present there is no test / reaction that could show which patients are at risk for developing this “potentially catastrophic complication” (authors own term). So, especially if you are a woman, stay away – women suffer this complication more often than men according to some reports.
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Reference:
Grammatopoulos et al.: Hip resurfacings revised for inflammatory pseudotumour have a poor outcome. J Bone Joint Surg-Br 2009; 91-B: 1919-24
METAL ALLERGY CAUSING FAILURE OF SURFACE REPLACED HIPS – A CAUSE KNOWN FOR 34 YEARS
Recent issue of the renowned English Journal of Bone and Joint Surgery has two articles describing severe bone destructions around surface replaced hips. This destruction is caused by allergy to metal particles produced by the metal-metal surface replacement hip devices.
It appears that these destructions are so severe that the surgery is very difficult and sometimes unsuccessful. These severe destructions of skeleton may appear to be a newly upcoming complication, but it is not.
For 34 years ago, the London Professor Marc Freeman described closely this complication in patients operated on with the then used metal-metal total hips (the McKee-Farrar model). According to his studies the metal allergen in all these patients was the metal cobalt, one of the components of the cobalt-chrome alloy from which were made the McKee-Farrar total hips.
The present day surface hip replacement devices are made from similar metallic alloy – although how much similar I could not find. Yet, the surgeons have had ample time to prepare for this grave complication. What did they do during all these years?
Not much according to the most reports where this allergic complication is described as something new. Systematic reports on metal allergy in larger series of patients with surface replaced hips are coming mainly from England, but they appear not to be a problem at the English centre that started the modern surface hip surgery movement.
The authors reporting on the metal allergy causing bone destructions, however, do not mention the possibility of testing metal allergy in these patients, both before the surgery and when the suspicion on the metal allergy arises. On the whole the question of metal allergy, its predictive value, suitable tests, and like is still unclear. Only a few specialists are at present studying metal allergy and its development in patients with metal-metal artificial hips.
If these patients are really allergic only against cobalt, as in the original Freeman’s study, then one should seek after other metal alloys without cobalt for manufacture of surface replacement hip devices.
One such alloy is stainless steel. Why was stainless steel not used for metal-metal couples in total hip? For other disadvantages? For economic reasons? (All compatibility tests would be expensive in presence of an already approved cobalt-chrome alloy)
One thing is certain: Although the surface replacement procedure has increased spread, our knowledge about its influence on patient’s body is still marginal.
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Reference:
Evans M. E. et al. (M.A.R. Freeman): Metal sensitivity as a cause of bone necrosis and loosening of the prosthesis in total joint replacement. J Bone Joint Surg – Br 1974; 56-B : 626 - 42
AMERICAN ORTHOPAEDIC SURGEONS ANNOUNCE THE CREATION OF THE AMERICAN JOINT REPLCEMENT REGISTRY
The American Academy of Orthopaedic Surgeons, the umbrella organization of American surgeons announced the creation of an organization that will register at last 90% of all total joint replacement operations done in the USA.
The Joint Registry will register “the devices performance” (read “failures of the implanted devices”). In this way the Joint Registry will improve patient safety (by warning about badly performing devices?) and enhance medical care (through teaching the surgeons the experience gained from the large database).
Obviously such register is not a cheap affair, the initiation costs are estimated at 20 to 25 millions $$.
Who will pay it? All stakeholders of this nonprofit, independent organization: orthopaedic surgeons, government agencies, device manufacturers, patient support groups, hospitals.
If all goes well the capture of data will start in 2010.
Information for you:
When it begins to function, it would be an enormous enhancement in our knowledge what is right and what is wrong with artificial joint. The 2010 seem, however, a rather optimistic commencement date to me.
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http://www6.aaos.org/news/pemr/releases/release.cfm?releasenum=818
July 2009
ANTIBIOTIC PROPHYLAXIS BEFORE DENTAL TREATMENT – NECESSARY PRECAUTION OR DANGEROUS ABUSE?
Orthopaedic surgeons have considered a dose of prophylactic antibiotics to be necessary for patients with joint replacement who undergo any dental procedure. The reason for this recommendation has been the belief that any dental procedure sends a small clump of mouth’s bacteria into the circulation. These bacteria that all of us have in our mouths then stay five to ten minutes in the circulation and can stick to the surface of the total joint and produce an infection there.
This opinion is very widespread; association of American orthopaedic surgeons (AAOS) as well as other national associations of orthopaedic surgeons are all recommending this prophylaxis as a routine.
Swiss orthopaedic surgeons, infection control specialists, and bacteriologists made thorough search through all scientific literature on this issue published as yet to see if there is any scientific ground for this recommendation (Uckay 2008).
The facts they published are interesting and astonishing. Simple strong chewing and teeth cleaning can push equally many bacteria into the blood circulation as any dental work even if it is not invasive.
Direct proof that any total joint infection was caused by patients own mouth bacteria was actually never presented. The majority of late total joint infections, believed to be caused by mouth bacteria, is in reality caused by bacteria that are living on the skin – of the patient and of his / her surgeon.
On the other hand, there is very well documented fact that use of “prophylactic antibiotics” is causing side effects in up to 1 % of people who received them; from innocent skin rushes to life threatening severe allergic reactions.
The authors’ conclusion is clear: “Antimicrobial prophylaxis before dental interventions in patients with artificial joints lacks evidence-based information and thus cannot be universally recommended.”
Information for you: This NEWS is actually one year old. But I considered it necessary to repeat it. The numbers of bacteria resistant to once powerful antibiotics (Methicillin) is steadily increasing and is now a “global threat”. Abandoning the routine use of prophylactic antibiotics before dental procedures is one of the many small ways how to stop this growing global threat.
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References :
Uckay I et al.: Antibiotic prophylaxis before invasive dental procedures in patients with arthroplasties of the hip and knee. J Bone Joint Surg-Br 2008; 90-B: 833- 7
SKIN CLOSURE AFTER TOTAL HIP REPLACEMENT – WHICH METHOD IS BEST
Operation wound closure is an important part of the surgical procedure. The closure aims to promote rapid healing of the skin with an acceptable scar acceptable scar and without complications such as dehiscence (gap) or infection.
Three commonly used methods of closure are staples, sutures, and skin adhesive.
Surgical staples and sutures hold the edges of the skin together while it heals. They must be removed, usually after ten to 14 days.
The newest method, the skin adhesive is a polyacrylate produced in a liquid form. After application on the skin it polymerizes and holds the opposite edges together. The adhesive need not to be removed, it sloughs off about ten days after surgery itself.
In the market drive to promote the adhesive for use in total hip surgery the manufacturer and some surgeons suggested that the use of adhesive may offer advantages compared with the conventional methods of suture with staples.
English surgeons carried out a very careful study of the two skin suture methods, suture with staples and suture with adhesives on two patients groups. (Livesey 2009).
Careful assessment of resulting wound healing, inclusive of assessment of the cosmetic appearance of the scar by a plastic surgeons, in both groups could not discover any advantage of the use of plastic above the use of conventional staples.
Information for you: The suture with staples was trice as quick as the use of the plastic. The use of plastic needs also a surgeon who has gone a special course in its use. In comparison with the staples, the plastic is five times more expensive.
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References :
Livesey C. et al. Skin closure after total hip replacement. J Bone Joint Surg-B 2009; 91-B: 725 - 9
THE PAINFUL SURFACE REPLACED HIP
Surface hip arthroplasty is the recommended operation for young patients with hip osteoarthritis predominantly. In these patients the published midterm results were good. There occurred, however, also unexpected problems.
One of them is the diffuse unexplained pain in the surface replaced hip joint.
Recently, the British surgeons from Charing Cross Hospital, London, England, studied 26 patients with unexplained pain in their surface replaced hips.
It appeared that these patients need a quite more sophisticated examination to come to the probable cause of the pain.
The special CT (computer tomography) of their surface hips revealed that all but two of them had wrong position of their cup component. Conventional x-.ray picture in surface replaced hips cannot demonstrate the wrong position of the cup. On the other hand, the wrong position of the cup - a too large so called Inclination Angle (CLICK for a Picture) - produces increased wear of metallic particles.
This is usually demonstrated by high values of cobalt and chrome metals in the patients’ blood. Patients in this series had significantly higher values of blood cobalt compared with patients with well-functioning surface hips.
The high value of the metal in the blood and in the bone close to the surface hip produces a special kind of allergic-inflammatory reaction. The majority of these patients with painful surface hips have fluid collection and masses of soft tissues around the surface hip. To demonstrate these changes, however, one needs a specialized MRI apparatus.
Information for you: It seems that if you have a painful surface hip you need examination by a specialist who has access to these three examinations. Obviously, surface hip replacement is a specialized surgery that needs not only a carefully selected patient but also a carefully selected surgeon.
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References :
Hart A. J. et al.: The painful metal-on-metal hip resurfacing. J Bone Joint Surg- Br 2009; 91-B: 738 – 44.
WHICH TOTAL HIP MODEL FOR YOU – RECOMMENDATIONS AND REALITY
The conventional – metal –on- polyethylene – bearings in total hip arthroplasty produced very good results. Statistics demonstrated that 80 % of these models survive twenty years.
However, the “soft” polyethylene wears of causing a lot of problems (wear, osteolysis, cup failures) leading to premature failures of total hips especially in young people.
Therefore, the implant industry in close collaboration with surgeon developed hard on hard bearing systems of total hips: metal –on – metal and ceramic-on – ceramic systems. The main advantage of the hard- on- hard total hip models is the much reduced wear of the hard surfaces. This would be advantageous for young patients who wear out quickly the soft polyethylene cups of their metal-on-polyethylene hips.
On the other hand, published clinical data in carefully selected patients demonstrated that these hard on hard total hips functioned very well in young patients in short and medium term follow up. It was also shown that metal – on- polyethylene total hips functioned excellently in old patients ( > 75 years).
So the general recommendation from leading surgeons has been to use the hard-on- hard total joint models mainly in young patients whereas the metal -on –polyethylene models are appropriate for older patients. The hard-on-hard models are also more expensive so there is also an economical reason for this recommendation.
How do the surgeons follow these advices? Do they really use hard –on- hard total hip models predominantly in young patients and the metal –on- polyethylene in older patients?
Beginning in 2005, the International classification of diseases and operations included codes for identifying the three total hip models: the metal –on-polyethylene, the ceramic on ceramic, and metal on metal devices. The hospitals use these codes in their statistics over operations done in the hospital. These statistics thus allow following the use of total hips with different bearing surfaces throughout the United States.
Scientists from the Health Policy Studies in San Francisco, California had published recently such statistics comprising 112 000 total hip operations. (Bozic 2009).
It appeared that in the USA 69 % of young patients (< 55 years) operated on with a total hip arthroplasty will receive a device with hard –on-hard surfaces.
What is more interesting, it appeared that whole 30 % of old patients (> 75 years) will also receive a device with hard on hard surfaces.
Information for you: It seems that the many reports in scientific journals, on academic meetings, and on publishers’ advertising sites convinced the surgeons that young patients should have a total hip device with hard-on-hard bearing surfaces. It must be acknowledged, however, that we lack as yet the long the term results (10 years and over) for this kind of bearing surfaces.
What kind of old patients got the expensive hard-on-hard devices? According to the report the majority of these patients were privately insured. It seems that in this case the surgeon followed the conviction “if it is twice as expensive it must be also twice as good”. True?
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References :
Bozic KJ. Et al.: The epidemiology of bearing surface usage in total hip arthroplasty in the United States. J Bone Joint Surg-A 2009; 91-A: 1614 -20
OSTEOTOMY FOR TREATMENT OF HIP OSTEOARTHRITIS IN YOUNG PATIENTS – GOOD RESULTS IN EXPERIENCED HANDS
Dysplasia of hip joint leads to hip osteoarthritis (OA) already in young age. When OA develops and surgical treatment is indicated, the surgeon has two options. Either carry out osteotomy of the hip socket (acetabulum) to repair its faulty position, stop the further progress of OA, and mitigate pain.
Or to resort to total hip replacement.
Both methods have their restrictions. Osteotomy of the hip socket (so called periacetabular osteotomy – PA) can by done only in patients with relative mild osteoarthritic changes of the hip joint, Even so, many surgeons advise against this operation because uncertain results and many complications.
Modern total hip replacement has had as yet good results early after operation, but the results are deteriorating as longer time after surgery pass.
Above all, direct comparison of these two methods to show which produces better results, was lacking as yet.
Two Taiwanese surgeons published recently a study comparing these two operation methods directly (Hsieh 2009). They studied 31 patients who had osteoarthritis of both hips caused by congenital hip dysphasia. One hip in every patient was operated on with PA the other one with total hip replacement.
Seven years after surgery there was no difference in functional outcome in hips undergoing osteotomy and those with a total hip replacement. Actually more patients preferred the osteomized hip to totally replaced hip,
Information for you: This was a group of young patients, none of them > 50 years, all operated on by very experienced surgeon. The authors noted that OA in the osteotomized hip improved radiologically in 25% of patients. This would show that normalizing the anatomical situation of the dysplastic hip joint stops further progression of osteoarthritis.
If you face surgery for OA in a dysplastic hip joint you may discuss the possibility of PA with your surgeon. But remember that god result of this surgery are surgeon dependent, this is not an easy surgery.
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References :
Hsieh P-H. et al.; Comparison of periacetabular osteotomy and total hip replacement in the same patient. J Bone Joint Surg-Br 2009; 91-B: 883- 8
June 2009
WHAT IS YOUR TOP PRIORITY – THE BEST SURGEON OR THE BEST TOTAL HIP MODEL?
The independent Internet network (www.hipandkneenetwork.co.uk) organization has an information site for patients.
The prospective patients can participate in the network by registering their opinions, wishes, and expectations from a possible hip or knee total replacement surgery. They will do it by filling a self completed questionnaire.
Recently the network published a survey of these questionnaires for the period from September 2008 through to February 2009. Some interesting results emerged.
The length of pain symptoms in hip and knee symptoms is surprising: 22% of patients stated that they suffered joint pain for 8 years or longer. From the survey date it is not obvious if all these patients were candidates for total joint surgery. It is, however, plausible that at least a part of them were candidates; it would be then interesting to know, why they were waiting so long with their decision.
Another interesting question what was the top priority of possible candidates for total hip or knee replacement surgery. For 42% of candidates it was the freedom from pain during and after surgery, for 31% it was access to the best medical technology, for 24% it was the short recovery time. Curiously enough, with respect to the number of published articles, only 2% of all candidates were concerned about the length of the operative wound,
In considering the most important factors for replacement surgery itself, the vast majority of candidates (78% ) considered the reputation of their future surgeon to be the most important, whereas only 14 % considered the reputation of the total joint model most important, and only 8% considered the reputation of the hospital most important.
These data re interesting. The majority of the prospective patients considers the surgeon’s reputation closely related to the results of the replacement surgery. It is, however, difficult to differentiate what is this “reputation”. Where can the patient find any scale on which to measure “reputation” of his/her chosen surgeon.
Whereas most politicians proclaim that “free choice of a doctor” is one of the basic human rights, there is as yet no established system how the patient can proceed to find the surgeon with the “best reputation”.
Information for you: This is a report published by an “independent network organization”, financed partly by European Union, but it is unclear which surgeons participate. Yet, the opinions of the candidates for total joint replacement, especially the concern about the “reputation” (experience) of their future surgeon are very interesting and confirm the claims made in other reports: patients wish to know the reputation of the surgeons before they make their choice.
Any comments / recommendations?
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References :
Orthopaedic Product News (European Edition) February/March 2009, pp 20
LABRUM TEAR – A NEW DISEASE OF YOUNG PEOPLE WITH HIP PAIN
During the last ten years our knowledge of the young people hip joints developed tremendously. This has been the result of the introduction of two new diagnostic methods: magnetic resonance arthrography and hip arthroscopy.
In the early 80’ s the surgeons were referred to the x-ray arthrography pictures when examining soft tissues of the hip joint; this examination method, however, provided unclear fuzzy pictures. With this raw method the surgeons could see sometimes ruptures through the labrum in young people with Perthes hip disease or congenital hip dysplasia who had pain in their hips. But these examinations were difficult and done only seldom so that the general opinion was that labrum tear is a rarity
The magnetic resonance hip arthrography on the other hand was providing excitedly detailed pictures of the whole hip joint, both the bony structures and the soft tissues.
On these pictures the surgeons could for the first time see the soft tissue structure called labrum clearly. And they could for the first time see clearly the tears going through this structure in some people. And when looking through the arthroscope into such a hip joint, the surgeons could see the tear crossing through the labrum by a “naked eye”.
At once the surgeons had explanation for pain in the hip of the young people who had an apparently normal hip joint at conventional examination. Only successively the surgeon learned to know the “hip impingement sign” and to find skeletal change also on conventional x-ray pictures that previously would be declared as “normal”. (See also the chapter: Hip joint diseases / Impingement of the hip joint)
So today we know that the pain in the hip of the young people with seemingly “normal” hip joint is often caused by damage to the structure named “labrum”.
Today we can take “conventional” x-ray pictures of the hip joint of good quality in specific projection. We can discover skeletal changes on these special projection pictures indicating that soft tissues in the hip are suffering impingement by these small skeletal changes. The surgeons learned that the repeated impingement of the soft tissues, especially of the labrum, causes lasting damages of the labrum and pain in the hip area.
Obviously, when the surgeons know the cause of the hip pain they should remove it to make the patient pain free. So what about the treatment? There is the progress less distinct. The surgeons are unanimous whether only to excise (remove) the torn portion or suture it back.
They are unanimous in which cases to remove the changes in the hip skeleton that produce the impingement by a “small” arthroscopic operation and when to do a large open operation such as an osteotomy.
The surgeons are also unanimous when it is too late to do some of these smaller operations (arthroscopic removal of labral tear, or an osteotomy) because the damage of the hip joint cartilage has gone too deep.
Information to you:
This is an exciting development and all patients with unclear pain in the hip should know of it and seek a doctor for examination with the question: Do I have a labral tear that causes my hip problems? Do I suffer of impingement of my hip joint although the “conventional” x-ray pictures of my hip joint see “normal? Despite the exciting development many doctors are still not aware of the importance of hip impongment and of the resulting labral damage.
Studies showed that an “average” patient visited three doctors who misdiagnosed his hip condition before finding the fourth doctor that made the right diagnosis. So, be insistent and don’t accept a no!
References :
Beaule PE et al.: Acetabular Labral Tears. Current Concept Reviews. J Bone Joint Surg-Am 2009; 91-A: 701-10
HOW LONG WILL A TOTAL KNEE JOINT LAST? – 20 years at least
Patients often ask how long will their total knee device last. They get different answers, depending on the surgeon. A lot of these answers is unnecessarily pessimistic.
Recent report from the known American surgeon M.A.Ritter shows that a good total knee device may last 20 years and more. This surgeon had implanted since 1983 over 7 700 (7760) total knee devices named Anatomical Graduated Component (AGC total knee model, Biomet).
This report is about the model with the metal backed and cemented tibial polyethylene component. 98% of these total knee devices lasted 20 years.
With such very high general success rate, it was difficult to find factors that would improve the chances of success. The only such factor was patient’s age > 70 years.
The author attributes the success of this model to its relatively simple construction; all components are non modular, produced at the manufacturing plant. The other important factor is the metal-backing of the polyethylene tibial component.
Actually there is a proof how important this metal backing is for the survival of the whole total knee device.
Originally, there were two models on the market:
The "old" model had an all polyethylene tibial component. The polyethylene component was cemented directly to the raw surface of the trimmed tibia. The results of this model were catastrophic: 32 % of these devices failed during the first ten postoperative years. This model is not longer on the market
Then there is the present model; the only difference is that the present model has its polyethylene tibial component metal backed and the metal dish has a beam for anchoring in the tibial shaft. (See picture)
Picture: The upper picture shows the old AGC model, Note that the polyethylene tibiaal component has no metal backing
The lower picture shows the present AGC model. Note the metal backing dish with a beam for anchoring in the tibia (shinbone).
Information for you: These total knee results are better than any results of a total hip. Total knee replacement is really a successful surgery, although many doctors still do not believe it. So be not fright of any tales about the "not so successful total knee surgery" that some doctors still tell their patients.
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References:
Ritter M.A.: The Anatomical Graduated Componet total knee replacement. J Bone Jopint Surg . Br 2009; 91-B: 745 - 9
