Background: Complete arthroscopic repair can treat small to large rotator cuff tears (RCTs) with good outcomes; however, the repair might be compromised by inflammation.
Purpose: To investigate the prognostic value of preoperative lymphocyte to monocyte ratio (LMR), a marker of systemic inflammation before surgery, in arthroscopic rotator cuff repair.
Study design: Case-control study; Level of evidence, 3.
Methods: Between January 2014 and January 2016, primary small to large RCTs without stiffness, significant muscle fatty infiltration, or atrophy were completely repaired in 110 consecutive patients and followed. Preoperative LMR was obtained from blood routinely examined 1 day before surgery. Descriptive data and pre- and intraoperative variables were collected. Correlation analysis and multivariable linear regression analysis were used to determine the relationship between preoperative LMR and recovery including American Shoulder and Elbow Surgeons (ASES) score, Constant-Murley score, Fudan University Shoulder Score (FUSS), visual analog scale (VAS) score for pain, and range of motion (ROM). Poor recovery was defined as ASES score <80, shoulder stiffness as external rotation ≤20°, and pain as VAS score >3. The predictive value of preoperative LMR was determined by receiver operating characteristic (ROC) curve.
Results: A total of 99 patients (101 shoulders) were followed for 2.88 ± 0.43 years. Overall, mean ASES, Constant-Murley, FUSS, and VAS scores were significantly improved at the final follow-up; however, 27 cases had either ASES <80, shoulder stiffness, pain, or a combination of these. Correlation analysis and multivariable linear analysis showed that preoperative LMR was the only factor independently associated with functional recovery, pain, and ROM. Patients with poor recovery had lower preoperative LMR than those with good recovery. Based on the ROC curve, the cutoff value of preoperative LMR was 4.760. Patients with preoperative LMR <4.760 had significantly inferior clinical outcomes compared with their counterparts. The corresponding specificity was 0.542, and sensitivity was 0.779.
Conclusion: Arthroscopic repair for small to large RCTs yielded good outcomes; however, some patients still had inferior functional scores, shoulder stiffness, or pain, which correlated with the level of preoperative systemic inflammation. As a marker of systemic inflammation, preoperative LMR could be prognostic for rotator cuff repair.
Keywords: lymphocyte monocyte ratio; prognosis; rotator cuff; shoulder.