Abstract
The purpose of this study was to examine a relationship between function of hip abductor-adductor muscles and Trendelenburg(T) sign. We examined 39 joints of 35 cases who had received operations for total hip arthroplasty (THA); 20 joints of 18 cases with positive T sign, and 19 joints of 17 cases with negative T sign at 8 week after surgery. To investigate function of hip abductor-adductor muscles between the cases with positive T sign and those with negative T sign, we employed a torque machine (MYORET RZ-450). Function of hip abductor-adductor muscles was evaluated in terms of abductor-adductor torque (0°) and time rate of tension development (TRTD) of abductor-adductor peak torque.
The results of abductor-adductor torque were almost the same between both groups. But TRTD of abductor was slower in cases with positive T sign than in cases with negative T sign (p<0.001). TRTD of adductor was faster in cases with positive T sign than in cases with negative T sign (p<0.05). In addition, positive T sign group can be discriminated from negative T sign group by the discriminating analysis (92%), using four parameters; abductor torque, adductor torque, TRTD of abductor and TRTD of adductor.
These data clearly indicated that function of hip abductor-adductor muscles is involved in the appearance of T sign after THA.
