KRAFTVERHALTEN DER HUFTUMGREIFENDEN MUSKULATUR UND GEHFAHIGKEIT BEI PATIENTEN NACH IMPLANTATION EINER ZEMENTFREIEN HUFTENDOPROTHESE

There are only a few studies which could support conclusions concerning the strength of the muscles surrounding the hip joint and especially concerning the strength relationships following implantation of endoprotheses. The aim of this study was to examine the pre- and postoperative course of strength deficits in this musculature compared to clinical parameters and the uninvolved side. Fifty-eight patients between 30 and 67 years of age, in whom individual total hip protheses were implanted were clinically examined prior, 9 weeks and 6 months after surgery. Moreover, the maximum isometric strength of abductors, flexors, and rotator muscles as well as maximum isokinetic strength of the extensors and flexor musculature at 60°/s and 120°/s were measured. The flexor and extensor musculature already showed a clear increase in maximum strength after 9 weeks and 6 months (90-124%). By contrast, the isometric strengths of the rotators increased only slightly, the abductor strength decreased after 6 weeks to below the preoperative baseline level and attained this level again only after 6 months. The clinical parameters Trendelenburg sign, limping and walking capacity were clearly improved after 6 months, but no correlation to the abductor strength could be demonstrated. It is concluded that limp-free gait can be attained even without maximum strength increase in the abductors, which are important for fluid gait, at least for short distances. The importance of regular training of the rotator and abductor musculature in coxarthrosis is emphasized to delay limitation of movement and decreased strength in the sense of capsule pattern.