Which muscle performance can be improved after arthroscopic Bankart repair?

Abstract

Background: There are no published reports available regarding neuromuscular control recovery in nonathletic patients after arthroscopic (A/S) Bankart repair. This study aimed to compare neuromuscular control and performance of the rotator cuff muscles between patients who underwent A/S Bankart repair and normal controls. Methods: In total, 32 nonathletic patients who underwent A/S Bankart repair were compared with 32 asymptomatic nonathletic volunteers. Neuromuscular control index (time to peak torque and acceleration time), muscle strength ratio, muscle strength, and muscle endurance of the internal rotators (IRs) and external rotators (ERs) were measured using an isokinetic device at an angular velocity of 180 degrees/s, with 90 degrees shoulder abduction. Results: The neuromuscular control indices of both IRs and ERs were significantly lower in patients who underwent A/S Bankart repair than in normal controls (time to peak torque, IRs: 1059 +/- 143 ms vs. 679 +/- 226 ms, P=.011; ERs: 595 +/- 286 ms vs. 379 +/- 123 ms, P=.044; acceleration time, IRs: 75 +/- 16 ms vs. 62 +/- 15 ms, P=.039, ERs: 70 +/- 19 ms vs. 54 +/- 18 ms, P=.047). Muscle endurance was significantly lower in patients who underwent A/S Bankart repair than in normal controls (IRs: 670 +/- 1 J vs. 718 +/- 2 J, P=.002, ERs: 422 +/- 6 J vs. 501 +/- 2 J, P=.044). The neuromuscular control index showed a significant negative correlation with muscle endurance for both IRs and ERs after the operation (IRs: r = -0.737, P=.003, ERs: r = -0.617, P=.019). Conclusion: Compared with normal controls, patients who underwent A/S Bankart repair did not show complete recovery of neuromuscular control of IRs and ERs, although their muscle strength ratio and muscle strength had fully recovered. (C) 2019 Published by Elsevier Inc. on behalf of Journal of Shoulder and Elbow Surgery Board of Trustees.