Internal rotation of the tibial component is frequent in stiff total knee arthroplasty.

BACKGROUND: Stiffness complicating TKA is a complex and multifactorial problem. We suspected internally rotated components compromised motion because of pain, patellar maltracking, a tight medial flexion gap, and limited femoral rollback on a conforming lateral tibial condyle. QUESTIONS/PURPOSES: We sought to determine: (1) the incidence of internal rotation of the femoral and tibial components in stiff TKAs; (2) if revision surgery that included correction of rotational positioning improved pain, ROM, and patellar tracking; and (3) if revision altered nonrotational radiographic parameters. METHODS: From a cohort of 52 patients with TKAs revised for stiffness, we performed CT scans of 34 before and 18 after revision to quantify rotational positioning of the femoral and tibial components using a previously validated scanning protocol. RESULTS: All 34 patients with TKAs had internal rotation of the summed values for tibial and femoral components (mean, 14.8°; range, 2.7°-33.7°) before revision for stiffness. The incidence of internal rotation was 24 of 34 femoral (mean, 3.1°; internal) and 33 of 34 tibial components (mean, 13.7° internal). Revision arthroplasty improved Knee Society function, knee, and pain scores. Mean extension improved from a contracture of 10.1° to 0.8° and flexion from 71.5° to 100°. Postrevision CT scans confirmed correction of component rotation. Nonrotational parameters were unchanged. CONCLUSIONS: We recommend CT scanning of patients with stiff TKAs before surgical intervention to identify the presence of internally rotated components. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Fifteen-year to 19-year follow-up of the Insall-Burstein-1 total knee arthroplasty.

This represents a 15-year to 19-year follow-up of 100 Insall-Burstein-I posterior-stabilized knee prostheses implanted in 86 patients from 1986 to 1989 and originally reported at 10 to 12 years (Thadani et al, 2000). In the original cohort, 6 failures occurred by 10 years. At 15 to 19 years, 55 patients (66 knees) had died; 18 patients were followed with clinical examination and radiographs, and 11 by telephone; 3 knees in 2 patients were lost. There were no new failures or additional surgeries from 10 to 19 years. Three knees exhibited osteolytic lesions. No case required revision due to symptomatic osteolysis or polyethylene wear. Using revision as end point, survival was 92.4% at 19 years. In summary, the prosthesis is likely to outlive the patients when classic indications for age and activity are respected.