[Balance of soft tissues in total knee arthroplasty for patients with knee of varus deformity and flexion contracture].

OBJECTIVE: To explore the technique of the soft tissue balancing in the total knee arthroplasty (TKA) for the patients with the knees of varus deformity and flexion contracture.

METHODS: From January 2001 to December 2005, 86 patients (19 males, 67 females; age, 57-78 years; average, 66 years) with the knees of varus deformity and flexion contracture underwent primary TKA and the balancing of the soft tissues. All the patients had suffered from osteoarthritis. The unibilateral affection was found in 68 patients and the bilateral affection in 18. The varus deformity angle was averaged 12.3 degrees (range, 6-34 degrees). The soft tissue varus accounted for 56.7% and the bony varus accounted for 43.3%. The flexion contracture < 10 degrees was found in 21 knees, 10-19 degrees in 45 knees, 20-29 degrees in 22 knees, and > 30 degrees in 16 knees, with an average angle of 18.9 degrees.

RESULTS: The flexion contractures were improved. Before operation the average angle of the flexion contracture was 18.9 degrees but after operation only 4 patients had a residual flexion contracture of 5 degrees and the remaining patients had a complete correction. The follow-up for 37 months (range, 6-72 months) in all the patients revealed that only 6 patients had a residual flexion contracture of 5-10 degrees and the others had a full extension. Before operation the average varus angle was 12.3 degrees (range, 6-34 degrees) and the average tibiofemoral angle was 174.7 degrees (range, 170.3-175.6 degrees), but after operation the residual varus angle > 3 degrees was only found in 2 patients. The complications occurring during operation and after operation were found in 6 patients, injuries to the attachment of the medial collateral ligaments in 2, patellar clunk syndromes in 2, cerebral embolism in 1, and lacunar infarction in 1, with no nerve disorders left after the medical treatment. No skin necrosis, the cut edge infection or deep infection occurred.

CONCLUSION: The balancing of the soft tissues is a major management for correction of the varus deformity and the flexion contracture. The proper balancing of the soft tissues can achieve an obvious recovery of the function and correction of the varus deformity after TKA.