Plasma Nerve Growth Factor Is Associated With Early Postoperative Shoulder Stiffness in Patients With Degenerative Rotator Cuff Tears.

OBJECTIVE: This study was to investigate the correlation between plasma nerve growth factor (NGF) and postoperative range of motion (ROM) in patients with rotator cuff tears (RCT). METHODS: From January 2022 to March 2024, a total of 135 patients with degenerative RCT were included. The patients were divided into Stiff group (n = 42) and Non-Stiff group (n = 93) accordingly. The receiver operating characteristic curve (ROC) and area under the curve (AUC) were drawn to evaluate the predictive value of plasma NGF for postoperative joint stiffness. The Spearman test was used to analyze the relationship between plasma NGF and joint motion, VAS score, and joint function scores (UCLA score and Constant score). The relationship between plasma NGF and postoperative ROM and risk of joint stiffness was evaluated by restricted cubic spline (RCS) analysis of independent variables. RESULTS: In the preoperative and postoperative comparison, the two groups improved in joint flexion, VAS pain score, and joint function, except that the external rotation of the Stiff group did not change before and after surgery. After surgery, the ROM of the Stiff group was still significantly limited, and the ROM and joint function scores were lower than those of the Non-Stiff group (p < 0.01). CONCLUSION: This study suggests that reduced plasma NGF in patients with degenerative RCT may be associated with early shoulder stiffness, showing a negative non-linear dose-response relationship. On a clinical basis, plasma NGF is beneficial to quantify the risk of early shoulder stiffness after RCT.