Prediction of Bilaterality in Patients With 1 Posterosuperior Rotator Cuff Tear

Abstract

Background: In patients with a known unilateral posterosuperior rotator cuff tear (PSRCT), the ability to predict a contralateral PSRCT may assist in earlier diagnosis and improved patient outcomes. Purpose: To determine factors associated with bilateral PSRCT and their most predictive combinations using a nonhospitalized general population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This study involved 736 individuals (n = 1472 shoulders) drawn from a rural cohort. PSRCT was diagnosed using magnetic resonance imaging. Symptoms of the contralateral shoulder were not considered. The demographic, physical, social, metabolic, and imaging factors, as well as comorbidities, were evaluated using logistic regression analysis. Cutoff values for the significantly associated variables obtained from multivariable logistic regression analysis were calculated using the receiver operating characteristic (ROC) curve. The areas under the ROC curve (AUCs) of the combinations of significantly associated variables were compared using the DeLong method to determine the combination most predictive of bilateral PSRCT. The likelihood ratio and the posttest probability for each of the combinations were assessed. Results: Age ≥61 years, manual labor, critical shoulder angle (CSA) ≥35°, retraction degree of Patte ≥ grade 2, biceps tendon injury, and metabolic syndrome were significantly associated with bilateral PSRCT in multivariable analysis ( P < .001). The 1-by-1 combination of any 4 of the 6 associated factors significantly increased the AUC of any smaller combinations of those 6 factors ( P < .001). The AUCs of the 4-somes were all similar ( P ≥ .383) and were not significantly increased by further addition of identified associated factors ( P ≥ .422). Any combination of 4 of the 6 associated factors was highly predictive of bilateral PSRCT, each having a minimum AUC of 0.70, a likelihood ratio of >10, and a minimum posttest probability of 80%. Conclusion: Unilateral PSRCT, accompanied by any 4 of the variables of age ≥61 years, manual labor, CSA ≥35°, retraction degree of Patte ≥ grade 2, biceps tendon injury, and metabolic syndrome, is highly predictive of PSRCT in the other shoulder.

Shoulder activity of the contralateral shoulder as a prognostic factor in patients with arthroscopic rotator cuff repair

“…Of cases with RCTs on one side, contralateral RCTs have been reported to occur in 25.1%–38.6% of cases in the general population. 11 , 28 However, there are a few reports on the contralateral shoulder of patients undergoing ARCR with or without a RCT. In this study, RCTs in the contralateral shoulder of the ARCR were evaluated by US, and their prognosis was investigated.…”

“… 28 Gwark et al reported that age ≥61 years, manual labor, critical shoulder angle ≥35, retraction degree of Patte ≥ grade 2, biceps tendon injury, and metabolic syndrome were significantly associated with bilateral posterosuperior RCTs. 11 Yamaguchi et al reported that the presence of rotator cuff disease was highly correlated with age; the average age was 48.7 years for patients with no RCT, 58.7 years for those with a unilateral tear, and 67.8 years for those with a bilateral tear. 33 In this study, the mean age of the patients was 64.7 years, and with respect to shoulder activity in jobs and sports, 65 (62.5%) patients were active, suggesting a relatively high incidence of bilateral RCTs.…”

“…The prevalence of rotator cuff tears (RCTs) increases with age. 36 Other risk factors for RCTs include extrinsic factors, such as acromion morphology, 17 the presence of spurs, 27 critical shoulder angle, 15 shoulder overuse, 11 , 22 and also intrinsic factors, including aging, 36 inflammation, 23 oxidative stress, 37 and hypoxia. 1 Comparative data on asymptomatic and symptomatic RCTs are available 34 , 35 ; however, it is unclear why RCTs are symptomatic or not.…”