Effect of recombinant human growth hormone on rotator cuff healing after arthroscopic repair: preliminary result of a multicenter, prospective, randomized, open-label blinded end point clinical exploratory trial.

BACKGROUND: This study evaluated the effect of systemic injection of recombinant human growth hormone (rhGH) on outcomes after arthroscopic rotator cuff repair. METHODS: This multicenter, prospective, randomized, comparative trial, randomized patients who underwent arthroscopic repair of large-sized rotator cuff tears into 3 groups: rhGH 4 mg group (n = 26), rhGH 8 mg group (n = 24) , and control group (n = 26). Sustained release rhGH was injected subcutaneously once weekly for 3 months postoperatively. The healing failure rate (primary end point), fatty infiltration, and atrophy of the supraspinatus muscle, and functional scores (Constant and American Shoulder and Elbow Surgeons scores) were evaluated at 6 months. Range of motion, pain visual analog scale, and serum insulin-like growth factor-1 level were measured at each follow-up. RESULTS: The healing failure rate was similar between groups (rhGH 4 mg group, 30.8%; rhGH 8 mg group, 16.7%; and control group, 34.6%; all P > .05) The proportion of severe fatty infiltration (Goutallier grade ≥3) was 20.8% in the rhGH 8 mg group, 23.1% in the rhGH 4 mg group, and 34.6% in the control group (P > .05). Functional outcomes, range of motion, and pain visual analog scale were similar between groups (all P > .05). The rhGH 8 mg group showed more increased peak insulin-like growth factor-1 level (279.43 ng/mL) than the rhGH 4 mg group ((196.82 ng/mL) and control group (186.31 ng/mL), which was not statistically different (all P > .05). No rhGH injection-related major safety issues occurred. CONCLUSIONS: This preliminary study showed no statistically significant improvement in healing or outcomes related to the treatment of rhGH after rotator cuff repair. However, further study with more enrolled patients after resetting the rhGH dose or daily administration protocol would be mandatory.