Mobile-bearing, congruent patellofemoral prosthesis: short-term results.

PURPOSE: To report the short-term outcome of the low contact stress (LCS) patellofemoral prosthesis in 51 knees. METHODS: 12 men and 37 women aged 23 to 79 (mean, 53.4) years underwent 51 consecutive LCS patellofemoral replacements. All patients had symptomatic isolated arthritis in the patellofemoral joint with well-preserved tibiofemoral compartments. All knees were evaluated pre- and post-operatively. The new Oxford scoring system was used. Anteroposterior, lateral, and skyline weight-bearing radiographs were reviewed. RESULTS: The mean follow-up period was 4.2 years; no patient was lost to follow-up. The mean new Oxford Knee score was 13.9 preoperatively and improved by 13.7 at 3 months (p<0.001) and by further 7.1 at 12 months (p<0.001). Any change after 12 months was not significant (p=0.73). 18 of the knees developed patellar maltracking and resulted in subluxation and lateral tilt of the patella with severe polyethylene wear. 10 (20%) of the knees were revised; 8 with patellar maltracking were revised to total knee arthroplasty (n=3) or patellofemoral arthroplasty with a different implant (n=5), whereas 2 with disease progression were revised to total knee arthroplasty. The estimated survival rate of the prosthesis was 73% at 4.5 years and 48% at 5.5 years. CONCLUSION: The revision rate for the LCS patellofemoral prosthesis was high (20%).

Total knee arthroplasty in a patient with Hardcastle syndrome.

Diaphyseal medullary stenosis is a rare skeletal dysplasia of unknown etiology with potential autosomal dominant genetic inheritance. A variant of diaphyseal medullary stenosis has been associated with a high risk of malignant transformation, specifically in the form of malignant fibrous histiocytoma. This potential combination of diaphyseal medullary stenosis and malignant fibrous histiocytoma is known as Hardcastle syndrome. This article presents a case of a 32-year-old man with osteoarthrosis of the knee as a consequence of Hardcastle syndrome for which he underwent a total knee arthroplasty (TKA) with a satisfactory outcome. Our case demonstrates pathological and radiological signs of skull involvement, which has not previously been reported in the literature as a manifestation of this condition. We discuss the differential diagnoses of diaphyseal dysplasia that should be considered in such cases and advocate the use of a triad of preoperative radiological investigations, including early thallium isotope bone, magnetic resonance imaging, and computed tomography. We also discuss the use of long-stemmed prostheses, extramedullary femoral alignment, and the concerns of using Computer Assisted Surgery for total knee arthroplasty in patients with diaphyseal medullary stenosis.With the short-term success of TKA in Hardcastle syndrome, we found that TKA could be considered as an alternative treatment option in symptomatic patients. However, due to the fact that the potential for malignant transformation in this syndrome is unchanged by a TKA, the patient should remain under close clinical and radiological follow-up.

High-tech and low-tech orthopaedic surgery in Sub-Saharan Africa.

BACKGROUND: Zambia's governmental health system suffers from shortage of surgical supplies and poor management skills for the sparse resources at hand. The situation has been worsened by the dual epidemics of HIV disease and tuberculosis. On the other hand the private medical sector has benefited greatly from less bureaucracy under the goverment of the Movement for Multi-party Democracy. DISCUSSION: The Zambian-Italian Orthopaedic Hospital in Lusaka is a well organized small unit providing free treatment of physically disabled children. The running costs are met from the fees charged for private consultations, supplemented by donations. State of the art surgical techniques are being used for congenital and acquired musculo-skeletal abnormalities. Last year 513 patients were operated upon free of charge and 320 operations were performed on private patients.