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PubMed2002

[99mTc-labelled antigranulocyte anibody fragment Fab scintigraphy (sulesomab, leukoscan) and three-phase bone scintigraphy in the study of painful hip and knee prosthesis].

We aim to assess the diagnostic utility of the combination of a three phase bone scintigraphy (3FBS) and scintigraphy with Fab'antigranulocyte fragments-99mTc (Sulesomab, Leukoscan) in patients with painful joint replacements. We studied 29 patients (22 women and 7 men with mean age 64 years) with knee (15) and hip (14) prosthesis. Scintigraphy was performed with a Siemens Orbiter 75 gammacamera with all purpose collimator. 3FBS was performed as usual with 740 MBq of MDP-99mTc. Sulesomab images were obtained at 1 and 4 hours following injection of 740 MBq, with 300,000 cts per view (knee) and 500,000 cts per view (hip). Both scintigraphic studies were interpreted visually by two nuclear medicine physicians with a 0, 1, 2, 3 score corresponding to normal or mild, moderate or intense hyperactivity respectively. Interpretation criteria for bone infection was Sulesomab uptake grade 2 or 3 in a moderate or large sized area, with congruent hyperactivity on the bone scan. Grade 1 uptake with Sulesomab was considered nonspecific associated to nonseptic conditions. The frequent pattern of uptake in synovial femoral tissue (cap shape sign) in knee prosthesis was considered nonspecific. Diagnostic confirmation procedures were surgery and culture (9) and follow-up (20). All six septic joints were correctly identified. A false positive result was obtained in a case of mechanical loosening in the knee. Negative studies were very helpful in the exclusion of infection. Our conclusion is that sensitivity is high, 100%, and that a normal or grade 1 Sulesomab image makes the presence of infection improbable.

Antibodies, Monoclonal↗
PubMed1995

[Long-term results of Insall's total condylar knee prosthesis (10-to-13-year follow-up)].

We have studied 10 to 13 years postoperatively the first 105 total knee arthroplasties using the Total Condylar, a semiconstrained prosthesis with sacrifice of the cruciate ligaments, inserted between 1979 and 1983, in 99 patients (6 were bilateral). The average age of these patients was 73.5 years at the time of arthroplasty. At the time of this review, 46 patients had died (49 prostheses) and 10 were lost to follow-up. Five knees had failed (4 infections), requiring prosthesis removal in three cases. The other 38 patients (41 knees) survived: 35 were available for detailed clinical and roentgenographic evaluation, 6 knees had only a clinical, x-ray, questionnaire or telephone evaluation. To evaluate the results of these prostheses, we used 3 different rating systems the SOFCOT rating system the Hospital for Special Surgery rating system the new scoring system of the Knee Society. The results with the HSS system were excellent or good in 80% of the cases. The rate of satisfactory results, somewhat lower than those of North American studies, is probably explained by the advanced age of our patients. All these prostheses were cemented. There was no aseptic loosening at 10 to 13 years follow-up. In assessing these results we can confirm the reliability of the first model of the Insall prosthesis, in spite of a small range of sizes, and of a rudimentary ancillary, which resulted in important positioning mistakes. We can confirm that a cemented knee prosthesis with sacrifice of the cruciate ligaments is reliable at more than 10 years of follow-up. The technical advancements: larger range of component sizes metal backed tibial plates better ancillary, which permits exact and reproducible placement posterially-stabilized system should yield even better long-term results, approaching those of total hip arthroplasty.

Adult↗
PubMed1995

[Clinical evaluation of total knee prosthesis: comparative analysis of scores].

PURPOSE OF THE STUDY: Numerous scoring systems have been described for the evaluation of total knee arthroplasty. The aim of this study was to analyze the reality of the results and the differences between clinical evaluation scores. MATERIAL AND METHOD: We calculated the mean overall scores (Hungerford, Laskin, Hospital Special Surgery and Mansat) in a series of 89 PCA total knee arthroplasties with a mean follow-up of 4.5 years. We compared postoperative score values considered as borderline between poor and good results with survival curves. RESULTS: The mean values of the postoperative scores were very similar and showed no significant differences: Hungerford: 83 pts; Laskin: 80 pts; HSS: 80 pts; and Mansat: 86 pts. The comparison between the four survival curves was statistically significant: the Hungerford curve was the most optimistic (62 per cent success at 8 years) when compared to the Laskin score (16 per cent success at 8 years). DISCUSSION: The scores do not express the same reality. For mean values close or identical to the scores, the quality of the results may be different. Our analytic method reveals considerable differences explained by the juxtaposition of clinical and functional parameters in the scores. The Hungerford and Mansat scores are principally based on clinical criteria while the Laskin score is more functionally orientated. The HSS score is more even handed. CONCLUSION: It is incorrect to appreciate the value of survival curves if the scores are based on functional criteria as these parameters will naturally deteriorate over time and therefore these scores do not reflect the real quality of the arthroplasty. The Knee Society Score is probably the most interesting system since functional and clinical parameters are separated.

Data Interpretation, Statistical↗
PubMed2000

Fracture of posterior-stablized tibial insert in a Genesis knee prosthesis.

We report a case of acute failure of a Genesis total knee arthroplasty (Smith and Nephew Orthopaedics, Memphis, TN) resulting from fracture of the eminence of the polyethylene posterior-stabilized tibial insert implanted in a revision procedure. A hyperflexion movement was responsible for shear stress on the insert with subsequent breakage. The correct diagnosis was obtained by arthroscopy, and the open substitution of the broken insert led to complete recovery of the prosthesis. This is the first report of mechanical breakage of a Genesis prosthesis.

Aged↗
PubMed1975

[Arthroplasty of the knee. Prosthesis without uni- or bicondylar hinge].

The prosthesis has two components. The femoral component is metallic surfacing the condyle and a tibial plateau in polyethylene replaces the original one. The prosthesis can be uni or bi-condylar. Operative technique has to be very precise and the position of the prosthesis needs accuracy. The advantages are: minimal bone resection, small implant harmonic action with the knee joint as a whole. 20 patients with I8 months follow up are reviewed, problems are infections and pain in the patello-femoral joint. The results on pain and walking are good. Stability depends on accurate indications.

Aged↗
PubMed1989

Torsional characteristics of the Minns meniscal knee prosthesis.

A quasi-static analysis of axial rotation of the femoral component and the torsional forces at different angles of knee flexion was performed on knee preparations. The meniscal knee design had very much lower axial torque against axial rotation characteristics through the whole range of knee flexion than the total condylar design and could be rotated up to 59 degrees in both internal and external rotation before dislocating (i.e., a total axial rotation of 118 degrees). The sliding plateau design had torque-rotation characteristics comparable to those of the total condylar design. Torsional strain was measured on cemented and uncemented preparations, and little difference between the two was observed.

Biomechanical Phenomena↗
PubMed2002

Late dislocation of rotating platform in New Jersey Low-Contact Stress knee prosthesis.

Five patients with late rotational dislocation of the rotating platform bearing in the New Jersey Low-Contact Stress total knee arthroplasty are reported. The prostheses had functioned well for 8 to 12 years before failure. Preoperative radiographs showed asymmetric femorotibial joint spaces. Entrapment of the dislocated bearing in three patients and spontaneous reduction of the dislocated bearing in another two patients were seen at revision. Femorotibial ligamentous instability was found after reduction. The retrieved polyethylene bearings showed advanced wear and cold flow deformities and the thickness was reduced. The revision arthroplasty was accomplished by replacement with a thicker bearing element. Progressive femorotibial ligament laxity and reduction of the thickness of polyethylene with wearing break down the originally well-balanced soft tissue tension of the knee. The rotational degree of the rotating platform bearing is unrestricted, which may result in late dislocation. Polyethylene wear is unavoidable in knee prostheses using metal contact with polyethylene even with a mobile-bearing design. Efforts to reduce polyethylene wear are mandatory.

Aged↗
PubMed2005

A novel method for in vivo knee prosthesis wear measurement.

Wear remains an important cause of failure in knee replacement. Of the current methods of early performance assessment or prediction, simulators have been un-physiological, single X-ray film analyses remain limited by accuracy and retrieval and survival methods have a prohibitive time scale. An accurate method is needed to allow a timely assessment of polyethylene component wear in vivo, when a new design is introduced, in order to predict likely outcome. We present a new method for measuring wear in vivo that we believe will allow this prediction of long-term wear. X-ray film pairs were taken of implanted prosthetic metal components. When the X-ray system was calibrated, projections of the appropriate Computer Aided Design (CAD) model could be matched to the shapes on the scanned X-ray films to find component positions. Interpenetration of the metal femoral component into the polyethylene component could then be established and represents our estimate of "wear". This method was used to measure in vivo prosthesis wear to an accuracy of 0.11 mm.

Arthroplasty, Replacement, Knee↗
PubMed2001

The Genesis total knee prosthesis: a 10-year followup study.

This current author reports on the results of 100 consecutive patients with osteoarthritis who underwent a primary cemented total knee replacement using the Genesis prosthesis and who have been followed up for at least 10 years after surgery. In patients in whom the posterior cruciate ligament was sacrificed (combined flexion and angular deformities > 15 degrees to 20 degrees) a posterior-stabilized cam module was affixed to the femoral component and a posterior-stabilized polyethylene was used. More than 95% of patients in both groups had excellent pain relief. The mean flexion was 114 degrees in the group of patients in whom the posterior cruciate ligament was sacrificed and 117 degrees in the group of patients in whom the posterior cruciate ligament was retained. Partial bone cement tibial radiolucencies were seen in 12% of the patients in whom the posterior cruciate ligament was retained and 2% of the patients in whom the posterior cruciate ligament was sacrificed. At 10 years, 76% of the group in whom the posterior cruciate ligament was retained had excellent results and 20% had good results. In the group in whom the posterior cruciate ligament was sacrificed 75% had excellent results and 23% had good results. The survivorship was 96% in the group of patients in whom the posterior cruciate ligament was retained and 97% in the group of patients in whom the posterior cruciate ligament was sacrificed.

Aged↗
PubMed1999

Infection of a knee prosthesis with Tsukamurella species.

A 69-year-old woman with a history of multiple infections of a postoperative wound from a knee replacement was diagnosed with an infection with Tsukamurella sp. The infection was treated with a course of vancomycin and pipercillin/tazobactam, followed by a course of clarithromycin, ciprofloxacin, and ethambutol. The patient responded well. This represents the first report of a Tsukamurella infection of an artificial joint.

Actinomycetales↗
PubMed1993

The Geomedic knee prosthesis. A long-term follow-up study.

A retrospective long-term follow-up study of 189 Geomedic total knee arthroplasties in 143 patients was performed. One hundred and eighteen knees were replaced in patients with rheumatoid arthritis and seventy-one knees were replaced in patients with osteoarthritis. Fifty-seven knees were examined clinically with an average follow-up of 11 years. Seventy percent of these knees were painless. Lucent lines at the tibial bone-cement interface were observed in 62% of the follow-up radiographs (81 knees, mean follow-up: 10.5 years). Thirty-four prostheses (18%) were removed, with loosening of the tibial component as the main cause. Retropatellar pain was not a significant problem. The 13-year survival rate was 78%, with implant removal as an endpoint. Radiographically loosened components included, the 13-year survival rate was 58%.

Adult↗
PubMed1997

[A unicompartment knee prosthesis: the effect of the positioning of the tibial plate on the functional results].

The authors analyse the results of 51 unicompartmental knee prostheses with 1 to 12 years follow-up (mean follow-up: 5 years). The results were evaluated using the scoring system of the "Knee Group" of the SO.B.C.O.T. (Société Belge de Chirurgie Orthopédique et de Traumatologie). This analysis demonstrates that the quality of the results depends on implant positioning. The authors suggest positioning the tibial implant parallel with the healthy plateau and slightly distal, i.e. to position the tibial implant perpendicular to the epiphyseal axis and not to the mechanical axis, as is systematically done with the usual tibial cutting guides. When this ideal positioning was respected, 77.5% of the patients had a score above 90 points (out of a possible maximum of 100 points) and 12.5% had a score between 75 and 89 points. When this condition was not respected, none of the knees obtained more than 75 points. The difference was statistically significant (p = 0.0001).

Adult↗
PubMed2004

Knee arthrodesis using circular external fixator in the treatment of infected knee prosthesis: case report.

A patient (68 years old and male) underwent total knee replacement because of arthrosis, but he subsequently had infection due to a wound problem. Although he underwent early debridement, antibiotherapy, and soft-tissue operation, treatment failed because of improper soft-tissue coverage and progression of the infection. Therefore, the prosthesis was removed and a spacer with antibiotic was placed, in order to provide soft-tissue coverage and to eradicate infection. After 2 months, the patient underwent knee arthrodesis using a circular external fixator to achieve a stable lower extremity and to facilitate return to activities of daily living. We obtained knee fusion at 4 months without any requirement for secondary procedure of soft tissue and bone graft. There was no major complication. Arthrodesis with circular external fixator is a reliable and successive method that should be preferred for the treatment of infected knee replacement.

Aged↗