Using the anterior capsule of the hip joint to protect the tensor fascia lata muscle during direct anterior total hip arthroplasty: a randomized prospective trial
Abstract Background The direct anterior approach for total hip arthroplasty (THA) has specific advantages, but injury to the tensor fasciae lata muscle (TFLM) remains a concern. This injury in part negates some of the advantages of the intermuscular approach, because injury of the muscle fibers of the TFLM can lead to less satisfactory clinical results. Thus, in this study, we propose an intraoperative method to protect the TFLM and demonstrate its feasibility.Methods Fifty-six patients undergoing THA by the direct anterior approach were divided randomly into two groups. In group A, the TFLM was protected by an autogenous tissue “pad” created from the anterior capsule of the joint that was rotated to protect the TFLM from direct contact with the retractors needed to expose the joint space. In group B, the operation was carried out in the typical fashion with no other protection of the TFLM except the attempt by the surgeons to consciously avoid compressive injury of the TFLM. We evaluated the magnitude of changes in the muscle cross-sectional area (MSCA) and fatty atrophy (FA) early and postoperatively between groups by magnetic resonance imaging. The differences in blood hemoglobin and serum levels of myoglobin, lactate dehydrogenase (LDH), and creatine phosphokinase (CPK) were compared at 8, 24, and 48 h, postoperatively. Postoperative drainage volume and pain evaluated by visual analogue scores (VAS) were compared between the two groups.Results LDH, CPK and myoglobin in group B were significantly higher than those in group A at 8, 24, and 48 hours after the surgery. (p<0.05) Compared to the group A, the decrease of hemoglobin in group B displayed significantly at 24 and 48 hours after surgery. (P<0.05) The significantly increased MSCA and FA of TFLM were demonstrated in group B. The PDV and VAS in group B were significantly higher compared with those in group A. (P<0.05)Conclusions Using the anterior capsule of the hip joint as an autogenous, protective capsular tissue pad to limit the trauma to the TFLM during a direct anterior approach to THA is an effective method to protect the TFLM and improve the clinical effect.