Abstract
Purpose
The posterolateral or posterior approach for total hip arthroplasty has the advantages of preserving the hip abductor musculature and providing good visualization during femoral preparation and component insertion. Although posterolateral approach is one of the popular approaches in hip arthroplasty, it has been reported high dislocation rate as a drawback. To compensate the drawback the repair of short external rotator of hip is thought to be important. Therefore, we investigated incidence of failed repaired short external rotator muscles, dislocation rate and time of failure between tendon to tendon and tendon to bone repair technique through prospective study more than 1 year follow up.
Materials and methods
We performed 213 hip arthroplasties in 202 patients from May 2012 to January 2015. After exclusion of 15 hips due to follow-up loss(9 hips), death(2 hips), greater trochanteric fragment displacement(3 hips) and severe contracted short external rotator(1 hip), we investigated 198 hips in 187 patients. 57 patients were male and 130 patients were female. The mean age of patient was 70.4 (32–98) years. Reattachment short external rotator with posterior capsule to postero-superior aspect of greater trochanter(tendon to bone group, 111 hips) or to the tendon(tendon to tendon group, 87 hips) was performed. Two No.26 metal wire markers were fixed at the greater trochanter tip and short external rotator tendon respectively with a distance less than 1.2cm, and the distance between two wire markers was observed at postoperative 1 day, 2 weeks, 3 months, and annually radiographs in neutral position. When the distance was more than 2.5cm or one of the wire markers was invisible, we defined them the failure of short external rotator repair. The mean follow up period was 28.8 (12–45) months.
Results
Failure rate of tendon to bone repair technique(17.1%) was significantly less as compared to that of tendon to tendon repair technique(70.1%)(p<0.001). The failure of short external rotator repair happened mostly within postoperative 2 weeks, which was 89.5% in tendon to bone(p=0.025) and 93.4% in tendon to tendon repair (p<0.001). Dislocation was observed in 2 (1.8%) hips in tendon to bone repair group and in 7 (8.0%) hips in tendon to tendon repair group respectively, which was significantly higher dislocation rate in tendon to tendon repair group. A significant correlation was also observed between failure of short external rotator repair and dislocation (p=0.032).
Conclusions
Tendon to bone repair technique is superior to tendon to tendon technique in terms of failure rate of short external rotator repair in hip arthroplasty. Tendon to bone repair of short external rotator with posterior capsule was beneficial to reduce dislocation rate as compared with tendon to tendon repair technique. As majority of failure of short external rotator happened within postoperative 2 weeks, restriction of internal rotation should be recommended through the period
