Nonoperatively managed small- to medium-sized subscapularis tendon tears: magnetic resonance imaging evaluation with a minimum of 5 years of follow-up

Abstract

Background Isolated or combined subscapularis (SSC) tendon tears are frequently found in patients with shoulder pain. The purpose of this study was to evaluate the structural changes associated with SSC tear in a consecutive series of patients with nonoperatively treated small size to midsize SSC tendon tears using magnetic resonance imaging (MRI). Methods In this retrospective case series, all patients with an isolated or combined SSC tendon tear treated nonoperatively between 1999 and 2019 were identified from our MRI and clinical databases. Twenty-one patients with a mean age of 52.6 years (range 26.6-64.8, standard deviation 9.3) with a second MRI scan at a minimum of 5 years of follow-up were enrolled. The mean follow-up was 8.6 years (range 5.6-12.6, standard deviation 1.8). Initial and last follow-up MRI scans were used to determine concomitant cuff lesions, size of the SSC tear, fatty infiltration of the SSC muscle, and biceps pathology. Results Five patients had an isolated SSC lesion; 7 patients had a concomitant tear of the supraspinatus, and 9 patients had a supraspinatus and anterior infraspinatus tendon tear. At diagnosis, 14 patients had a type 1 SSC lesion as classified by Lafosse et al, 4 patients had type 2, and 3 patients had type 3 lesions. Nineteen patients (90%) were found to have an SSC tear progression of at least one Lafosse grade ( P < .001); however, no tear had progressed to an irreparable type lesion (defined as Lafosse type 5). In addition, the size of SSC tendon tears increased significantly from 75 mm 2 to 228 mm 2 ( P < .001). At the final MRI scan, the grading of fatty infiltration increased by 1 grade in 4 cases and by 2 grades in 4 cases ( P = .042). At the final follow-up, in eight patients, the condition of the long head of biceps tendon was unchanged from the initial MRI; in nine patients, there was a newly subluxated biceps tendon, and in 6 patients, there was a newly ruptured long head of biceps tendon ( P < .001). Conclusion After a mean of 8.6 years, almost all nonoperatively treated SSC tendon tears had increased in size, but only one-third showed additional progression of muscle fatty degeneration on MRI scan. None of the SSC lesions became irreparable during the observation period.

Identifying key factors associated with subscapularis tendon tears and developing a risk prediction model to assist diagnosis

“…Although a good clinical outcome was obtained after arthroscopic repair of SSC tendon tears [ 15 – 17 ], the current sensitivity of MRI in SSC tendon tears was not ideal. The preoperative omission of SSC tendon tears could result in long-term pain and dysfunction of the shoulder, accompanied by progression of muscle atrophy, fatty infiltration, and increased tearing [ 18 ]. Yoon TH et al found that SSC tendon tears combined with advanced fatty infiltration had a high retear rate of 78.6% despite clinical improvement through surgery [ 19 ].…”

Clinical Approach to Inconclusive Subscapularis Tear Diagnosis: a Meta-analysis

“…Although the repair of SSC tears with arthroscopy has achieved good clinical results, the sensitivity of diagnosis of SSC tears with MRI is not ideal at present 10 . If an SSC tear is missed, it may cause long-term shoulder pain or dysfunction with muscle atrophy, fat infiltration, and extended tear areas 11 . During arthroscopic rotator cuff repair, it was observed that SSC tears were missed in 43.1% of patients, and the fatty infiltration of SSC tendons, which was initially overlooked, showed further expansion during revision 12 .…”

The prevalence, classification, radiological and arthroscopic findings of intratendinous subscapularis tears

“…Intratendinous tear has not been introduced in the current classiications of SSC lesions [1][2][3]. Incomplete visualisation could lead to failure to diagnose SSC tears and subsequently have negative impacts on outcomes after rotator cuf repair [4][5][6].…”