Abstract
BACKGROUND: To develop an injectable recombinant human bone morphogenetic protein 2 (rh-BMP-2) hybrid material and evaluate its clinical efficacy in promoting tendon-bone interface healing in patients with rotator cuff injuries through clinical outcome assessments and MRI-based imaging analysis. MATERIALS AND METHODS: This study included patients with rotator cuff tears who had an inadequate response to conservative treatment. The injectable rh-BMP2 hybrid material was synthesized. Ultimately, a total of 92 patients completed the final follow-up and were included in the analysis, with 46 patients in the experimental group (receiving the BMP-2 hybrid injection) and 46 in the control group (receiving no injection).Clinical evaluations were conducted preoperatively, at 1 and 3 months postoperatively for the Visual Analog Scale (VAS), and at 3 months and 1 year postoperatively for shoulder range of motion (shoulder flexion, external rotation, internal rotation), the American Shoulder and Elbow Surgeons (ASES) score, and Constant-Murley score. At the final follow-up (1 year), the abduction strength ratio and MRI signal-to-noise quotient were recorded. RESULTS: At the 1-year final follow-up, the BMP-2 group showed significantly better outcomes across multiple key measures compared to the control group. The BMP-2 group showed superior outcomes in ASES score (93.58 ± 5.21 vs. 90.68 ± 7.17, p = 0.03), Constant-Murley score (87.17 ± 5.55 vs. 83.93 ± 6.18, p = 0.01), and Shoulder flexion (168.70°±12.83° vs. 163.70°±13.12°, p = 0.05). External Rotation range was significantly better in the BMP-2 group (68.70°±12.25° vs. 62.61°±12.33°, p = 0.02). The abduction strength ratio favored the BMP-2 group (82.25%±6.55% vs. 77.63%±10.23%, p = 0.01), and the MRI signal-to-noise quotient was significantly lower in the BMP-2 group (2.03 ± 0.59 vs. 2.26 ± 0.52, p = 0.05), indicating better tendon healing quality. VAS scores at 1 months were significantly lower in the BMP-2 group (1.24 ± 0.48 vs. 1.63 ± 0.69, p = 0.00). CONCLUSIONS: The material can sustained release BMP2, which effectively promotes tendon-bone healing after rotator cuff repair, improves the function of the affected shoulder and reduces the rate of retear. It can provide a new possibility for improving outcomes after rotator cuff repair. TRIAL REGISTRATION: The questionnaires and methodology of this study have been registered with the Chinese Clinical Trial Registry (Registration number: ChiCTR2600118568.Registered on 09/02/2026.Retrospectively registered). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12891-026-09618-y.