Isokinetic Force-Velocity Curves in Patients Following Implantation of an Individual Total Hip Prosthesis

Abstract

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 endoprostheses. The aim of this study was to examine the post-operative course of strength deficits in this musculature compared to clinical parameters. Fifty-eight patients between 30 and 67 years of age, in whom individual total hip prostheses were implanted, were clinically examined prior, 9 weeks and 6 months after surgery. Moreover, the maximum isometric strengths of abductors, flexors, and rotator muscles as well as maximum isokinetic strengths of the extensors and flexor musculature at 60 degrees/s and 120 degrees/s were measured. The flexor and extensor musculature already showed a clear increase in maximum strength after 9 weeks and 6 months. By contrast, the isometric strengths of the rotators increased only slightly, the abductor strength decreased after 9 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 a capsule pattern.

Changes in Hip and Knee Muscle Strength in Patients Following Total Hip Arthroplasty

“…This defi cit in strength was most likely a result of the disease process of hip OA and a reduction in muscle activity. We thus believe that previous studies using preoperative strength 5,6,8,9) or uninvolved side strength 2,5-7) as a reference value may have overestimated the postoperative recovery of muscle strength.…”

Assessment of Hip Extensor and Flexor Strength Two Months After Unilateral Total Hip Arthroplasty

“…Published investigations documenting torque production of the hip joint musculature before hip arthroplasty are limited (10,16,18,20,22). In fact, there are limited studies focusing on the torque-producing ability of the extensors (3, 10, 18) and flexors (3,10,18,20) before THA. Concerning the hip extensors, Horstmann and colleagues reported that an individual before THA generated 52% of the torque produced on the uninvolved side before total hip surgery tested isokinetically at 60Њ·sec Ϫ1 (10).…”

“…Isokinetic strength has been successfully used in another published investigation to assess an individual's ability to produce torque of the hip joint musculature (10). In the present study, we used a Cybex (Henley Health Systems, Sugarland, TX) isokinetic system to assess torque production of the hip extensors and flexors before and 60 days after surgery.…”

“…To date, many published investigations have focused attention on the torque-producing ability of the hip abductors (15,18,19). Literature is limited on examination of both hip extensor and flexor torque production after surgery (10,18). Moreover, evaluation of both hip extensor and flexor torque production during the early period after hip arthroplasty is limited also (3,10).…”

“…Literature is limited on examination of both hip extensor and flexor torque production after surgery (10,18). Moreover, evaluation of both hip extensor and flexor torque production during the early period after hip arthroplasty is limited also (3,10).…”