Risk Factors for Rotator Cuff Repair Failure and Reliability of the Rotator Cuff Healing Index (RoHI) in Thai Patients: Comparison of the RoHI With a Modified Scoring System

BACKGROUND: The success rate of surgical treatment for rotator cuff (RC) tear ranges from 16% to 94%. The Rotator Cuff Healing Index (RoHI) is a system for predicting failure after RC repair and is based on a combined score of factors, including age, anteroposterior (AP) tear size, tendon retraction, fatty infiltration of the infraspinatus muscle, bone mineral density (BMD), and level of work activity. PURPOSE: To determine the factors leading to RC repair failure in a Thai population, to test the reliability of the RoHI in this population, and to compare the RoHI with a modified RoHI (m-RoHI) based on the factors for repair failure as determined. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: This study included 133 Thai patients who underwent arthroscopic RC repair between February 2012 and February 2021. Postoperative magnetic resonance imaging was performed at 6 to 24 months to evaluate RC healing. Variables that might affect failure rates were evaluated, including demographic characteristics, AP tear size and retraction, radiographic measurements, and magnetic resonance imaging findings. The m-RoHI was created using factors that significantly predicted repair failure on multivariate analysis. The area under the receiver operating characteristic curve was calculated to determine the reliability of the RoHI and to compare the reliability of the RoHI and m-RoHI to predict failure rates. RESULTS: Multivariate logistic regression analysis revealed that body mass index ≥23 (adjusted odds ratio [OR], 9.02; P = .034), high work activity (adjusted OR, 19.53; P = .008), AP tear size ≥2.5 cm (adjusted OR, 19.04; P = .001), and a retraction size of 2 to <3 cm (adjusted OR, 20.36; P = .013) were the independent factors that predicted repair failure in our population. BMD was not independently predictive of repair failure. We used these 4 significant independent factors to generate the m-RoHI. The area under the curve of the final adjusted m-RoHI was slightly improved as compared with the original RoHI, but this difference was not significant (0.827 [95% CI, 0.741-0.913] vs 0.780 [95% CI, 0.686-0.875], respectively; P = .447). CONCLUSION: The m-RoHI had a similar predictive value for repair failure to the original RoHI in our study population, but it did not require obtaining BMD. The m-RoHI may be useful in populations where BMD is not routinely obtained.