We reviewed the records of 1257 patients having 1625 total knee arthroplasties; all had pre-operative and postoperative perfusion lung scans and postoperative venograms which were classified as showing no thrombi, calf thrombi or proximal thrombi. Patients with calf thrombi were found to have a significantly greater risk for both symptomatic and asymptomatic pulmonary embolism compared with patients with no venographic thrombi. There were positive lung scans in 6.9% of patients with calf thrombi compared with 2.0% of patients with negative venograms (p < 0.001). Symptomatic pulmonary embolism occurred in 1.6% of patients with calf thrombi compared with 0.2% of patients with negative venograms (p = 0.034). The risk of pulmonary embolism was not significantly different between patients with treated proximal thrombi, and those with calf thrombi. Patients who develop deep-vein thrombosis despite prophylaxis are at increased risk for pulmonary embolism; these patients should receive treatment, or undergo follow-up studies to detect proximal propagation.

Over a two-year period 104 patients had 130 knee arthroplasties performed with the total condylar prosthesis at the Hospital for Special Surgery. At a 10- to 12-year review 58 patients (74 knees) had survived and were available for detailed clinical and radiographic evaluation. Of these, 38 knees (51.3%) were rated as excellent and 27 (36.5%) good. There were three (4.0%) fair and six (8.2%) poor results. Five of the six had had revision operations. The success of this early pattern of prosthesis supports the continued use of methacrylate cement for knee arthroplasties.

The survivorship method of analysis has been used to compare the failure rate and overall success of 1,430 cemented primary total knee arthroplasties performed at The Hospital for Special Surgery over a 15-year period. There were 224 total condylar prostheses with a polyethylene tibia, 289 of the posterior stabilised type with an all polyethylene tibia, and 917 posterior stabilised with a metal-backed tibial component. There were 12 failures in the total condylar series, giving an average annual failure rate of 0.65% and a 15-year success rate of 90.56%. The posterior stabilised prosthesis with a polyethylene tibia showed an average annual failure rate of 0.27% and a 10-year success rate of 97.34%, and this prosthesis with a metal-backed tibial component gave an annual failure rate of 0.19% and a seven-year success rate of 98.75%. The overall survival rate was not influenced by sex or age, diagnosis or the percentage of ideal body weight. No metal-backed tibial components have yet needed revision for loosening. It seems that infection will be the major cause of failure.

We have reviewed nine patients with Parkinson's disease who had 12 primary total knee arthroplasties and one revision. Deformities were corrected by conventional techniques and semi-constrained resurfacing arthroplasties were used. Follow-up ranged from two to eight years (average 4.3 years). Nine of the 12 primary arthroplasties were rated as excellent by the Hospital for Special Surgery knee score system, and three were rated as good. Contrary to previous reports, we feel that total knee arthroplasty performed on patients with Parkinson's disease, is a highly satisfactory procedure, alleviating knee pain and improving function.

This is a prospective study of 105 knees in 91 patients with idiopathic osteonecrosis of the femoral condyles, with an average follow-up of five years in 101 knees. Forty-eight of the 75 patients in whom the body weight was studied were obese and four of the 33 patients in whom a densitometry study was done showed decreased bone density. Prognosis is unfavourable if the lesion is larger than five square centimetres and if its width is more than 40 per cent of that of the condyle. Of the 22 patients followed up after conservative treatment 80 per cent were satisfactory. Of the 11 knees treated by arthrotomy alone 55 per cent were satisfactory. Of the 31 knees treated by osteotomy (21 with associated arthrotomy) 87 per cent were satisfactory. Arthrotomy did not significantly improve the results of osteotomies. The ideal correction was to 10 degrees of valgus. Of the 37 knees treated with replacement 95 per cent were satisfactory, and the best results were obtained with the total-condylar prosthesis.