Background: The use of hinged designs is usually reserved for severe deformities or instability in contemporary total knee arthroplasty (TKA). Results have been mixed with some authors reporting relatively high incidences of complications. The aim of this study is to present the results of primary TKA performed with a hinged prosthesis with a minimum 10-year follow-up. We also examined the factors that influence survivorship of this prosthesis. Methods: A total of 238 primary TKA procedures were performed using hinged prostheses. Indications included osteoarthritis, rheumatoid arthritis, posttraumatic deformity, and arthritis. Clinical outcomes were assessed using the Hospital for Special Surgery score. Radiologic assessment was performed at each follow-up. Survivorship was calculated based on the Kaplan-Meier method. All complications were documented. Results: Mean follow-up was 13.5 years (standard deviation [SD], 3.4). Mean flexion at final review was 118° (SD, 20°). Fifty-four percent and 20% reported excellent and good functional scores, respectively. Survivorship was 94% at 13.5 years in patients over 60 years of age and 77% in patients less than 60 years of age. Survivorship in patients with preoperative varus deformity was 96% and that in valgus knees was 79%. Conclusions The results of this study suggest that when rotating hinges are used for primary TKA, the best results are achieved in patients over 60 years old. The indications for this design in the setting of primary TKA include significant deformities, severe bone loss, and ligamentous laxity.

BACKGROUND: Management of the patella during total knee arthroplasty (TKA) is controversial. Multiple studies have examined mechanical and clinical results of TKA with native and resurfaced patellae with no clear consensus. METHODS: We surveyed a large cohort of consultant surgeons in a questionnaire based study in order to assess the indications for patella resurfacing and to correlate practice with degree of specialization, experience and volume of procedures performed. RESULTS: Six hundred and nineteen surgeons were included. The main indication for patella resurfacing was patellofemoral arthritis. The ratio of those who always:sometimes:never resurfaced was 1:2:1 irrespective of experience or volume performed. There was no difference between knee specialists and non-specialists (p = 0.977) or between high and lower volume surgeons (p = 0.826). Senior and high volume surgeons tended to always resurface. CONCLUSIONS: The majority of surgeons only sometimes resurfaced the patella. The number who always and never resurfaced were similar. There was a tendency for more experienced and high volume surgeons to always resurface.
Arthritis/*surgery ; Arthroplasty, Replacement, Knee/*methods/statistics & numerical data ; Cohort Studies ; Great Britain/epidemiology ; Humans ; Knee Joint/*surgery ; Orthopedics/*statistics & numerical data ; Patella/*surgery ; Patellofemoral Joint/surgery ; Questionnaires

Catastrophic failure of stemmed components in arthroplasty is an uncommon but a serious complication. Stem fractures and techniques for addressing these have been described following hip arthroplasty but much less so following total knee arthroplasty (TKA). We review three cases of catastrophic failure of the stem in rotating hinge revision TKA prostheses. We discuss the possible mechanism of failure and review the current literature addressing this topic. Metaphyseal support needs to be optimized in order to minimize load transfer to the stem and to the junction (and the risk of fracture) if a modular component is used. When constrained components are used, radiographs need to be carefully assessed for signs of proximal loosening. Nonmodular stems are also an option in this situation.
Arthroplasty ; Arthroplasty, Replacement, Knee* ; Hip ; Knee ; Prostheses and Implants