Background: Shoulder rotational muscle strength is an important factor to stabilize the glenohumeral joint for the patients with traumatic shoulder instability. The purpose was to compare the muscle strength recovery between arthroscopic Bankart (AB) and open Bankart & Bristow (BB) procedures.
Methods: Isokinetic concentric shoulder rotational muscle strength was evaluated in 119 patients with traumatic shoulder instability, treated with AB or BB procedure (Group AB: 64 shoulders vs. Group BB: 55 shoulders). We measured the peak torques using Biodex System 3TM(Biodex Co, NY, USA) at 60 and 180 deg/sec angular velocities at the pre-op. and 1.5, 3, 4.5, 6, 9, 12 months post-op., and calculated contra-lateral peak torque ratio (PTR), preoperative PTR, and contra-lateral total work (TW).
Results: There was no difference between both groups during external rotation, on the other hand, the PTRs and TW in the AB group were significantly higher than those in the BB group at 3 months post-op.(p < 0.01, 0.05). They recovered to the preoperative level by 6 months post-op. and kept on the same level between 9 and 12 months post-op.
Conclusion: The BB procedure could damage the subscapularis muscle during the exposure of the joint, and the internal muscle strength was weaker in the short term, however, they recovered to the preoperative level at 6 months post-op.
