Splitting the subscapularis at the upper two-third and lower one-third junction or in the middle during the Latarjet-Walch procedure does not affect the external rotation range of motion.

BACKGROUND

Our purpose was to investigate (1) the difference in external rotation range of motion (ROM) limitation between the two recommended subscapularis-splitting techniques (mid-split vs. upper 2/3 -lower 1/3 split) and (2) the differences in elevation ROM, internal rotation (IR) ROM, the functional outcomes and the IR strength between the two techniques in the Latarjet-Walch procedure.

MATERIAL AND METHODS

We conducted a prospective cohort study of patients with recurrent shoulder instability treated by the Latarjet-Walch procedure between January 2021 and January 2022. After a priori calculation of sample size, 32 patients were divided into two groups according to the type of intraoperative subscapularis split [upper 2/3 -lower 1/3 level split (LS group, n = 19) vs. mid-LS (MS group, n = 13)] performed in the Latarjet-Walch procedure.

RESULTS

The final external rotation with the arm adducted deficit (as compared to opposite normal shoulder) was not significantly different between the LS (9° ± 8°) and the MS (10° ± 8°, P = .8) groups. The final ER with the elbow abducted @ 90° (ER2) deficit was not significantly different between that of the LS (14° ± 12°) and the MS groups (12° ± 9°, P = .5). Only in the MS group were the final ER with the arm adducted deficit (P = .03) and the final ER with the elbow abducted @ 90° deficits (P = .05) significantly better (smaller) than the corresponding baseline values. The Rowe scores (P = .2) and the Shoulder Subjective Value (P = .7) were not significantly different between the two groups. There were no postoperative subluxations in either group. However, 3 patients tested positive in apprehension testing in the LS group compared to none in the MS group, the difference being statistically insignificant. The IR strength was 95% of the normal, unaffected shoulder in the LS group and 93% of the normal in the MS group (P = .6). Computed tomography scan evaluation showed that the transverse diameter index of subscapularis (upper subscapularis diameter/lower subscapularis diameter) was not different in the MS (0.9 ± 0.1) and the LS (0.9 ± 0.1, P = .3) groups.

CONCLUSION

We found no difference in final external rotation limitation between the upper 2/3 - lower 1/3 vs. mid-level subscapularis split techniques. The functional outcomes, the IR strength, subscapularis transverse diameter index, and fatty infiltration in the computed tomography scan were similar in both groups.