Muscle damage after total hip arthroplasty done with the two-incision and mini-posterior techniques

Some surgeons have suggested that a minimally invasive two-incision approach allows total hip arthroplasty to be done without cutting or damaging any muscle or tendon. To our knowledge that claim has not been supported by any published clinical or basic science data. Our purpose in doing this study was to quantify the extent and location of damage to the abductor and external rotator muscles and tendons after two-incision and mini-posterior total hip arthroplasty. Ten cadavers (20 hips) were studied. In each cadaver one hip randomly was assigned to the two-incision group and the contralateral hip was assigned to the mini-posterior group. After inserting the total hip arthroplasty components the muscle damage was assessed using a technique described previously. Damage to the muscle of the gluteus medius and gluteus minimus was substantially greater with the two-incision technique than with the mini-posterior technique. Every two-incision total hip replacement caused measurable damage to the abductors, the external rotators, or both. Every mini-posterior hip replacement caused the external rotators to detach during the exposure and had additional measurable damage to the abductor muscles and tendon. We do not support the contention that a two-incision total hip arthroplasty is done without cutting muscle or tendon. None of the two-incision hip replacements were done without cutting, reaming, or damaging the gluteus medius or gluteus minimus muscle or external rotators.