Report of the SICOT Presidential Commission on Documentation and Evaluation. Société Internationale de Chirurgie Orthopédique et de Traumatologie.
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Documentation↗
Biomedical subjects
R Poss
Publications and source records attributed to R Poss.
Clinical and radiographic evaluation of total hip replacement. A standard system of terminology for reporting results.
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Activities of Daily Living↗
Results of revision total knee arthroplasty performed for aseptic loosening.
One hundred thirty-seven revision total knee arthroplasties (TKA) performed in 117 patients with failed aseptic metal-to-plastic knees over ten years (1974-1984) were studied to determine the long-term clinical and roentgenographic results and were compared to primary TKA. The mean age was 65 years (range, 32-90 years). Fifty-three percent had rheumatoid arthritis, and 47% had osteoarthritis. The mean interval from initial to revision TKA (129 knees) was four years (range, three months to 11 years) and from the first to second revision (seven knees) was 2.4 years (range, seven months to 5.5 years). The most common reasons for failure were loosening (73%), patellar complications (13%), and instability (10%). The mean follow-up time was 5.2 years (range, two to 12 years). Function, instability, motion, and pain all improved after revision TKA, but these improvements were significantly less than those seen after primary TKA. One-third of the patients still ambulated with crutches, a walker, or not at all. While mean postoperative flexion was 100 degrees, 24% could not flex to 90 degrees. Most patients (90%) were malaligned at the time of failure and remained so after revision (78%). The increased incidence of radiolucent lines (tibial, 61%; femoral, 24%) was not related to increased failure. Complications were not increased over primary TKA. The failure rate was 5.8% at 5.2 years, or approximately 1% per year. A successful clinical result was defined as a knee with mild or no pain, mild or no instability, and flexion to at least 90 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Total knee arthroplasty with the kinematic prosthesis. Results after five to nine years: a follow-up note.
A review of the results of 192 kinematic total knee replacements five to nine years after the operation showed that the results were still satisfactory. At the time of the review, the ages of the patients ranged from twenty-two to eighty-seven years. About half of the patients had rheumatoid arthritis and the other half, osteoarthrosis. About 90 per cent of the results were rated good or excellent, and the average range of flexion was 109 degrees. Radiolucency was present around 40 per cent of the tibial components, 30 per cent of the femoral components, and 60 per cent of the patellar components, but the lines were thin and not progressive. The complications included loosening of the patellar components in five knees, one fracture of the tibial tray with loosening of the patellar component, one fracture of the patellar component, and one dislocation of the patellar component.
Adult↗
Enhanced computed tomographic techniques for the evaluation of total hip arthroplasty.
Computed tomography (CT) has revolutionized the evaluation of musculoskeletal pathology. Until recently, however, CT of the postoperative orthopaedic patient has been severely limited by its inability to provide useful information in the vicinity of acetabular and femoral implants. Typically the hardware produces extensive artifacts that can markedly degrade the whole image. Methods are now available to reduce the metal artifact. Following hip arthroplasty, these methods have been used to plan for revision arthroplasty and to evaluate the contralateral side for avascular necrosis.
Evaluation Studies as Topic↗
The application of advanced CT imaging and computer graphics methods to reconstructive surgery of the hip.
Advanced computed tomographic and computer graphic techniques enhance diagnostic accuracy and offer the means by which three-dimensional operative planning can be achieved. These techniques have been used to diagnose hip pathology, rehearse and evaluate surgical plans, assess postoperative results, and design individualized prostheses.
Computer Graphics↗
The fate of acetabular allografts after bipolar revision arthroplasty of the hip. A radiographic review.
We reviewed the radiographs of thirty-one patients (thirty-two hips) who had had revision of the acetabular component of a total hip arthroplasty with a bipolar socket supplemented by allograft and were followed for twenty-four to forty-eight months. The grafts were categorized according to their consistency (solid or crushed bone), the location of the acetabular defect (peripheral [rim] or central), and the extent of the acetabular defect (contained--the medial part of the acetabular wall was intact, or non-contained--it was deficient). We recorded the time to incorporation of the graft, the amount of migration of the socket in the superior and medial axes, and the percentage of graft remaining at the time of the most recent follow-up. The time to healing was similar for all categories of grafts. The central, contained, solid grafts had less resorption than did the central, contained, crushed-bone grafts, as evidenced by less migration of the socket during follow-up. The non-contained grafts, in both peripheral and central locations, were associated with high rates of migration and of instability of the socket.
Acetabulum↗
Case report 504: Unusual bilateral calcified giant cysts (geodes) in rheumatoid arthritis.
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Arthritis, Rheumatoid↗
Ultrasonic measurement of immobilization-induced osteopenia: an experimental study in sheep.
An animal model was used to examine the use of noninvasive transmission ultrasound to measure changes in bone mass which occur following disuse. Unilateral achilles tenectomy was performed on the left leg of eight adult sheep. Following a 12-week period of nonweight bearing, presacrifice transmission ultrasound measurements were taken across the calcanei of the intact and the experimental limbs and compared with those values taken postoperatively. Following specimen harvest, cross-sectional areas of the bones were quantified by microradiography and stereology, and compared with the in vivo ultrasound measurements. There was an average of 8.6% less total bone area, and 18.0% less trabecular volume fraction in the experimental nonweight-bearing limbs as compared with control intact calcanei. The difference in bone mass was associated with a 9.0% decrease in the velocity of sound from the postoperative to the presacrifice ultrasound measurements taken from the experimental calcanei, and a 2.3% increase in the control calcanei. The velocity of sound was found by the Student's t test to be a highly reliable discriminator between the experimental and control limbs.
Animals↗
Revision total knee arthroplasty in patients with osteoarthritis.
Total knee replacement (TKR) is a technically demanding surgical procedure, which is becoming more reliable and durable than total hip replacements. The authors describe the mechanisms of failure, the clinical evaluation of the painful TKR, the surgical planning techniques, and the overall results of revision TKR to date.
Humans↗
Long-term follow-up of cemented total hip replacement for osteoarthritis.
Two hundred twelve total hip replacements performed as a primary procedure have been followed for more than 10 years. One hundred thirty-six hips had adequate radiographic follow-up. Mechanical loosening of the acetabular and femoral component continue to be the major postoperative complications and in this series was 24 per cent. The incidence of femoral loosening has declined, however there is a continuing increase in acetabular revisions as well as an increase in bone-cement radiolucencies in relation to the acetabular component. Analysis of mechanical and technical parameters identifies those arthroplasties at increased risk of mechanical loosening, it is necessary to have two or more parameters of poor technique present before there is an increased incidence of loosening of the femoral component. Changes in stem design and cementing techniques in the early 1980s have addressed these parameters and in the mid-term have significantly decreased the incidence of mechanical failure. However we await the 10- to 15-year follow-up of these technical improvements to assess whether they will improve longevity of a biologic procedure. It is difficult to predict failure of cemented acetabular components and with longer follow-up there appears to be a steady increase in the incidence of acetabular loosening compared with a decrease in the occurrence of femoral loosening.
Acetabulum↗
Improving the fit of press-fit hip stems.
The implant-bone fit is critical to the longevity of press-fit total hips. Maximum contact on the internal cortical bone surface, especially proximally, produces more normal strain values and reduces micromotion and sinkage. Stem design computer software was developed to design both individualized hip stems that maximize implant-bone contact for a unique anatomy, and average anatomic hip stems in which the mean error of fit is minimized for many patients. Cadaver femurs were used to test the following two hypotheses: (1) Average anatomic stems, designed using the optimal-fit software for an average femoral geometry, improve implant-bone fit when compared with standard stems; and (2) Individualized optimal-fit stems provide an even better fit than average anatomic stems. Results showed that the average anatomical stems fit better than the standard stems. However, the individualized hip stems, designed from individual three-dimensional geometry data, fit the best.
Aged↗
The effects of modern cementing techniques on the longevity of total hip arthroplasty.
Modern prosthetic design and cementing techniques have dramatically improved femoral component fixation. Compared to studies reported in the 1970s, the incidence of radiographic loosening for periods up to 5 years postoperatively has been reduced by at least a factor of 10. These results are the benchmark by which alternative forms of femoral component fixation must be measured. With the likelihood of increased longevity of total hip arthroplasty resulting from improved fixation, the problems of wear debris from the bearing surfaces and loss of bone stock with time will become preeminent.
Bone Cements↗
Strategies for improving fixation of femoral components in total hip arthroplasty.
As strategies are considered for improving fixation of femoral components in total hip arthroplasty (THA), one is challenged to exceed the standard set by contemporary cement procedures. However, despite the improved ten- to 15-year clinical results anticipated with current cementing techniques, the limited fatigue strength of polymethylmethacrylate warrants continued investigation of alternative systems, particularly for younger patients and in revision arthroplasty. Design considerations for femoral stems for cementless THA include (1) initial mechanical stability afforded by the stem shape, (2) strength and stiffness of the stem, and (3) surface features relating to biocompatibility and attachment to bone. In one approach a fit-and-fill algorithm has been implemented to design stems that maximize contact between prosthesis and cortex in priority areas to achieve stability. Titanium is recommended for the fabrication of such stems because of its corrosion resistance, its biocompatibility, and its modulus, which is lower than that of cobalt-chromium alloy. Long-term fixation of these implants will be dependent upon the maintenance of normal strain patterns in the host bone. Achievement of this goal will require additional strategies that combine optimal fit and optimal material properties of the prosthesis.
Biocompatible Materials↗
The use of ultrasound in vivo to determine acute change in the mechanical properties of bone following intense physical activity.
The velocity of ultrasound was measured transcutaneously across the patella and tibia in 98 volunteers both before and after running the 26 mile Boston Marathon. Absolute sound velocities were 2.9% higher in those runners finishing before 3 h when compared to runners finishing after 3 h. Tibial velocities in males were 8.8% higher than in female runners. The mean velocity across the patella of three wheelchair racers was 28% lower than the mean combined patella velocity measured in all runners. These data suggest that 'faster' velocities are associated with bone that is better suited for high functional demands. Surprisingly, when pre- and post-race velocities were compared in each runner, there was a 1.6% increase in ultrasonic velocity across the tibia, and a 3.5% increase across the patella. An increase in ultrasonic velocity following extreme physical activity suggests that adaptive mechanisms exist in healthy bone to withstand, or possibly avoid, the microdamage which might be caused by repetitive cyclic loading.
Adult↗
Trochanteric advancement for recurrent dislocation after total hip arthroplasty.
Twenty-one patients had trochanteric advancement after experiencing an average of 3.9 dislocations in a mean period of 46 weeks following total hip arthroplasty. Before trochanteric advancement was performed, component malposition and mechanical impingement were excluded as causes of dislocation. Radiographic measurements revealed that the trochanter was advanced an average of 16 +/- 7.7 mm (1 SD). Four patients, all with rheumatoid arthritis, had trochanteric migration greater than 1 cm. Seventeen of the 21 hips had no further dislocations following trochanteric advancement, with mean follow-up period of 2.7 years. Two patients dislocated because of extremes in hip position and had no further dislocations. Two patients dislocated who had trochanteric migration greater than 1 cm. Only one patients with a technically satisfactory trochanteric advancement continued to dislocate repeatedly. In patients without component malposition or obvious sources of impingement, trochanteric advancement is an effective and safe procedure for prevention of recurrent dislocations after total hip arthroplasty.
Adult↗
Femoral expansion in total hip arthroplasty.
With increasing age, the femoral medullary canal expands and cortical thickness decreases. Examination of the radiographs of 22 hips that had undergone total hip arthroplasty revealed that at a mean interval of 11.5 years the medullary canal had expanded at an average rate of +0.328 mm/year (P less than .0001). There was a concomitant mean cortical atrophy of -0.155 mm/year (P = .0006). These rates of expansion are similar to those observed in natural aging. The presence of a femoral prosthesis is associated with temporal changes in femoral geometry similar in magnitude to those occurring in the natural femur. Because of the fundamental changes in load transmission caused by the presence of a femoral prosthesis, these geometric changes may be in part secondary to the bone's adaptation to altered load transmission, as well as to natural aging phenomena. Recognition of the pattern of natural femoral expansion suggests certain strategies for design criteria that seek to maximize fit.
Adult↗