Factors associated with pain in nonsurgically treated rotator cuff tears -A study with magnetic resonance imaging

BACKGROUND: In rotator cuff tears, some cases become asymptomatic with nonsurgical treatment, others remain symptomatic. The purpose of this study was to identify factors associated with pain in nonsurgically treated rotator cuff tears using magnetic resonance imaging (MRI). METHODS: In total, 108 shoulders diagnosed with supraspinatus (SSP) tendon tears using MRI were nonsurgically treated, and MRI was repeated after more than a year. The patients were divided into pain or improvement group according to whether the pain persisted or disappeared. Bursal fluid accumulation; SSP tendon retraction; subscapularis (SSC) tendon tears; infraspinatus (ISP) tendon tears; and Goutallier classification into SSC, SSP, and ISP were included as evaluation factors. Predictive factors for persistent pain on initial MRI and factors associated with persisting pain after nonsurgical treatment on repeat MRI were statistically analyzed using multivariate logistic regression analysis. RESULTS: The improvement group showed a significant decrease in bursal fluid accumulation compared with the pain group (p < 0.01). SSC tendon tears (OR, 4.42; 95% CI, 1.16–16.9; P = 0.03) on initial MRI were significantly associated with persistent pain. Bursal fluid accumulation (OR, 2.44; 95% CI, 1.18–5.07; P = 0.02) and SSC tendon tears (OR, 2.25; 95% CI, 1.15–4.39; P = 0.02) on repeat MRI were significantly associated with persistent pain. CONCLUSIONS: Bursal fluid accumulation decreased when pain improved. The involvement of SSC tendon tears can serve as a predictive factor for persistent pain. Pain may persist although patients with rotator cuff tears including SSC tendon tears are nonsurgically treated. LEVEL OF EVIDENCE: Level IV case-control study