Total knee replacement in patients with genu recurvatum

Between June 1987 and March 1997, 57 total knee replacements were done in 5 3 patients with at least 5 degrees hyperextension deformity as measured on physical examination. The average recurvatum measured 11 degrees (range, 5 degrees -20 degrees). No cases of major ligamentous instability, neuromuscu lar disease, or inflammatory arthropathy were identified before surgery. Be fore surgery, Knee Society knee, function, and pain scores averaged 41 poin ts, 41 points, and 13 points, respectively. A posterior cruciate-retaining prosthesis was implanted in all patients. The followup averaged 4.5 years ( range, 3-10 years). Knee, function, and pain scores improved to 81 points, 78 points, and 43 points, respectively. Postoperative extension averaged 0 degrees (neutral) (range, 10 degrees hyperextension-10 degrees contracture) . Only two (3.5%) knees had a hyperextension deformity after surgery. Both deformities measured 10 degrees and were in patients with a preoperative di agnosis of osteoarthritis. At final followup, no knee replacement was revis ed for any reason. In addition, only one case of a progressive radiolucent line greater than I nim (tibial Zone 7) was observed. Although the etiology of a hyperextension deformity should be elucidated before surgery, its pre sence does not preclude a well-functioning total knee replacement.