Range of motion after arthroplasty for the stiff osteoarthritic knee.

In 28 of 1656 total knee arthroplasties (TKAs) (1.7%) performed for osteoarthritis at this institution, the preoperative arc of motion was 60 degrees or less (average 47.5 degrees; range, 20-60 degrees). The outcome of 22 of the 28 TKAs (21 patients) is reported at a mean follow-up of 52.9 months (range, 24-144 months). Eighty-two percent of the cases were managed with standard soft-tissue releases and posterior cruciate-retaining implants and 18% with a cruciate-substituting design. The joint score rose from 28.8 to 82.2 and the Knee Society Score from 24.6 to 77 points. The mean postoperative arc of motion improved by 46 degrees-93.5 degrees. At latest follow-up, 68.2% of knees achieved maximal flexion of 90 degrees or more. Manipulation was performed in 22.7%. Complications were minimal. A functionally useful range of motion is possible after total knee arthroplasty in the majority of stiff osteoarthritic knees, often without the need for posterior cruciate substitution.

Body mass index as a predictor of outcome in total knee replacement.

The clinical and radiographic outcomes of 326 total knee replacements (TKR) in 285 osteoarthritic patients with body mass index (BMI) greater than 30 kg/m2 were compared with the results of a matched group of 425 TKR in 371 patients with BMI less than 30 kg/m2. At an average follow-up of 75.9 (48-144) months the Knee Society score (KSS) in the obese patients had increased by 41.9 points, and the joint score by 43.7. In the non-obese group the KSS rose by 40.2 points and the joint score by 42.6 points. Although patients with BMI greater than 40 kg/m2 achieved a lower final KSS the 'absolute improvement' appeared to be independent of BMI. Of the obese patient group 4.9% underwent a revision of their TKR, compared with 3.1% of the non-obese group. Although linear osteolysis (radiolucency) rates were comparable, focal osteolysis rates were 5 times those of control subjects when the BMI exceeded 40 kg/m2. Ten-year survivorship figures were similar for both obese and non-obese patients.

Cementless cup fixation in total hip arthroplasty after 5-8 years.

A series of 199 total hip arthroplasties was performed using a porous-coated, hemispherical press-fit acetabular cup. At a mean follow-up of 91.5 months 158 cups were available for clinical and radiological review. The mean age of the patients at the time of the index arthroplasty was 62.5 years. The mean Harris Hip score at final follow-up was 87.3. No shells were revised although eccentric polyethylene wear prompted liner replacement in two cases. Osteolysis was noted in six cases but predominantly in relation to the femoral stem. Focal pelvic osteolytic lesions were rare. All the cups were classified as stable on radiography.

Results of all-polyethylene tibial components as a cost-saving technique.

Since 1992, the authors have used an all polyethylene tibial component in relatively less active patients older than 70 years of age who present for primary total knee replacement. Results of 312 knee replacements performed between March 1992 and March 1998 are presented in the hopes of showing this technique as a viable cost saving measure. Three hundred twelve primary total knee replacements were performed by the same group of surgeons. Fourteen patients died before the first year postoperative evaluation, leaving an index group of 298 knees in 231 patients. All components were evaluated using the radiographic and clinical parameters of the Knee Society. Hospital for Special Surgery scores also were calculated. All patients were given the Short Form-36 Quality of Life Assessment preoperatively and annually postoperatively. Clinical scores showed dramatic improvement. There have been three revisions (0.7%) but none were for aseptic loosening. Radiographic review revealed 295 replacements with optimum fixation. To date, no patient has osteolysis. The cost differential was significant. The use of this type of tibial component has, to date, afforded excellent clinical and radiographic results. Additional followup is needed to show the longevity of these results and to monitor wear or subsidence of these prostheses. Should these results continue to prove satisfactory in this particular group of patients with relatively low physical demands, significant cost savings may be realized.

Cementless hemispheric acetabular component in total hip replacement.

A series of 198 total hip arthroplasties was performed using a porous-coated, hemispheric press-fit cup. One hundred and twenty-seven cups were available for clinical and radiological examination at mean follow-up of 10.6 years. The mean age at the index procedure was 61.2 years. The mean Harris hip score at final follow-up was 89.8. Three cups were revised for aseptic loosening and two liners were changed for eccentric wear and pelvic osteolysis. Nine additional patients showed mild or suspected osteolysis. Two cups were rated "fibrous" stable. There was no correlation between additional screw fixation of the press-fit cup and osteolysis or revision.

Proximally porous coated femoral stem in total hip replacement--5- to 13-year follow-up report.

A series of total hip replacements was performed using a proximally porous coated, tapered femoral stem system. At a mean follow-up of 8.1 (5-13) years, 80 out of 107 hips were available for clinical and radiological examination. The mean age at the index procedure was 58.6 years. The mean Harris Hip Score at final follow-up was 91.7. Radiological ingrowth was observed in 77 femoral stems, 2 stems were fibrous stable and 1 stem was loose.

Supracondylar nailing of distal periprosthetic femoral fractures.

Seven patients who sustained complex distal femoral fractures above total knee arthroplasties all treated by supracondylar (retrograde) femoral nailing were retrospectively evaluated. All the patients demonstrated uncomplicated postoperative follow-ups and returned to weight bearing between 2 and 3 months after surgery. No delayed healing occurred and alignment of the femur was satisfactory.

The case for porous-coated hip implants. The femoral side.

A series of 1163 total hip arthroplasties (THAs) using porous-coated femoral components were roentgenographically assessed for implant fixation. For 959 primary THAs followed from two to 12 years, the femoral revision rate was 1% and the ten-year survivorship rate was 96.4%; 150 young patients had a fixation failure incidence of only 1.3% at a mean follow-up period of 6.4 years; in 204 revision THAs, the femoral re-revision rate was 4% at a mean follow-up period of 53.4 months. Failures were largely related to inadequate femoral canal filling. Because of refinements in implant design and surgical techniques, a press fit of the implant is currently achieved in 94% of cases compared to 36% during the first five years. Porous-coated femoral components have yielded results equivalent to those with cement in primary THAs. Excellent results were observed in relatively young patients and patients with revisions.

Roentgenographic assessment of the biologic fixation of porous-surfaced femoral components.

Certain roentgenographic signs have value in predicting the fixation of a cementless femoral component to bone by osseointegration. Other signs have value in predicting the gross stability of a cementless femoral component. The authors have determined the specificity and sensitivity of the signs for osseointegration in cases in which the histologic fixation has been confirmed after implant removal. The authors have also determined the specificity and sensitivity of the signs for gross implant stability in cases in which the stability has been confirmed at reoperation. Statistical methods were used to determine a numeric value for each of these roentgenographic signs, and these values were combined into a score. The score was divided into fixation by osseointegration and mechanical implant stability. The two scores were then combined into an overall score. When signs of osseointegration were present, the implant was always stable, and the overall scores were the highest. When signs of osseointegration were absent, the mechanical stability varied, and the scores were lower. A neutral or slightly negative score correlated with failed osseointegration but secondary successful implant stabilization. A very low negative score correlated with gross implant instability. To confirm the validity of the scoring system, the two-year postoperative score was determined for 1005 cases in which the clinical outcome was known. A strong correlation between the presence of symptoms and a low score confirmed the value of the scoring system for diagnosing implant loosening as the cause of symptoms. As a second test, the two-year and five-year postoperative results were compared in the same patients. A high two-year score correlated with durable implant stability through five years. A low two-year score correlated with a higher incidence of late symptomatic loosening.