Platelet-Derived Growth Factor Synergistic Enhancement of Bone Marrow Stimulation for Enhanced Labral Repair and Functional Recovery in a Rat Bankart Model.

BACKGROUND: Bone marrow stimulation (BMS) is used to treat intra-articular defects, such as articular cartilage defects or to facilitate healing of soft tissue repair; however, BMS yields inconsistent clinical outcomes, potentially due to the inefficient delivery of endogenous progenitor cells.

HYPOTHESIS: Combining BMS with localized placement of platelet-derived growth factor (PDGF) would enhance in situ progenitor cell responses, leading to enhanced labral tissue repair and functional recovery in a rat model.

METHOD: A Bankart glenoid labral tear was created in the right shoulder of 50 adult rats. The animals were randomly divided into 5 groups: (1) healthy (baseline), (2) suture only (control), (3) suture + PDGF, (4) suture + BMS, and (5) suture + PDGF + BMS. Healing was assessed at 1.5 (n = 3), 3, and 8 weeks (n = 4). Baseline groups were included at 3 (n = 4) and 8 weeks (n = 5). At each timepoint, labral healing was evaluated by quantifying progenitor cell recruitment, tissue differentiation, and general morphology. Functional recovery was assessed weekly via gait analysis.

RESULTS: BMS alone failed to elicit cell recruitment to the injured labral region. However, the combined BMS + PDGF treatment resulted in a 7-fold increase in progenitor cell accumulation at the tear site compared with BMS alone (27.46 ± 11.51 vs 3.5 ± 3.26 cells/0.01 mm2, respectively; P < .001). The combined group was characterized by increased chondrogenic differentiation, greater glycosaminoglycan intensity, and significantly lower Pauli score. Furthermore, gait analyses confirmed that the combined treatment yielded the most robust functional recovery.

CONCLUSION: The synergistic application of BMS + PDGF provided a highly effective method for labral repair compared with isolated treatments, significantly enhancing progenitor cell recruitment, tissue regeneration, and functional recovery.

CLINICAL RELEVANCE: This study identifies a novel repair technique that overcomes limitations of standard suture-only repair. This strategy offers a promising translational approach to improve outcomes in shoulder labral reconstruction.

STUDY DESIGN: Controlled laboratory study.