Evaluation of muscle strength recovery following superior capsular reconstruction using a tensor fascia lata graft: A comparison with the unaffected side.

Abstract

Superior capsular reconstruction (SCR) using a tensor fascia lata graft has been performed in patients with irreparable rotator cuff tears and shoulder pseudoparalysis (PPS), and good clinical results have been reported. This procedure can be indicated for younger patients who are highly active in sports and manual labor from the viewpoint of joint preservation. However, this procedure supplements the defect with a graft that has no muscle contractility; therefore, the extent to which shoulder muscle strength is recovered after SCR remains unclear. We hypothesized that the recovery of muscle strength after SCR would not be normalized and would be only approximately 50% of that of the healthy (unaffected) side. This study aimed to evaluate muscle strength after SCR in patients with PPS due to irreparable rotator cuff tears and the extent of recovery by comparing with that of the unaffected side. In total, 20 patients who underwent SCR for PPS using a tensor fascia lata graft with a minimum 2-year follow-up were included. Shoulder muscle strength in abduction, internal rotation, and external rotation was evaluated using a handheld dynamometer. Muscle strength was compared to that on the unaffected side, and the affected/unaffected ratio was measured. Shoulder range of motion (ROM) and acromiohumeral distance (AHD) were also evaluated. The postoperative ROMs and AHD (4.0 ± 1.4 mm vs. 8.4 ± 1.9 mm, P < .001) were significantly improved compared to those preoperatively. In external and internal rotation, the muscle strength of the affected side was recovered by approximately 80% compared to that of the unaffected side. However, in abduction, the muscle strength of the affected side (2.9 ± 1.5 kg) could not reach 50% (48.0 ± 15.9%, range: 25.0-76.5%) of that of the unaffected side (5.9 ± 1.8 kg). Abduction strength was not sufficiently restored after SCR when compared to that on the unaffected side.