Background: While a number of studies have documented the very good
clinical results of arthroscopic rotator cuff repair, very few authors have
specifically assessed cuff integrity, supraspinatus atrophy, and fatty
infiltration and their influence on the clinical outcome.
Methods: We evaluated fifty-three consecutive patients (average age,
60.9 years) who had undergone arthroscopic repair of an isolated supraspinatus
tendon tear. After an average duration of follow-up of 26.4 months, all
patients were evaluated clinically with use of the Constant score and
underwent standardized magnetic resonance imaging at our institution. The
preoperative and postoperative magnetic resonance images were evaluated by two
independent observers who were blinded to the clinical outcome of the patient.
Evaluation criteria were cuff integrity; atrophy of the supraspinatus; and
fatty infilitration of the supraspinatus, infraspinatus, and subscapularis.
These findings were correlated to the clinical outcome.
Results: Regardless of the tendon integrity, every parameter of the
Constant score was significantly improved after the repair. The overall
average Constant score was improved from 53.5 to 83.4 points (p < 0.001).
The retear rate in our series was 25% (thirteen of fifty-three). Patients who
had a retear had significantly less abduction strength (p = 0.043) and a
significantly lower total Constant score (p = 0.012) than those who had an
intact repair. A higher degree of preoperative supraspinatus atrophy and
Stage-2 fatty infiltration of the supraspinatus were positive predictors of a
retear. Also, an older age was an important predictor of a retear (p = 0.011).
Progression of structural changes in the rotator cuff was halted when the
repair remained intact, but there was no significant reversal of fatty
infiltration or muscle atrophy. When the repairs failed, there was significant
progression of fatty infiltration and atrophy of the supraspinatus.
Conclusions: The clinical and structural results of arthroscopic
repairs of isolated supraspinatus tears are equal to those reported following
open repair. Fatty infiltration and muscle atrophy cannot be reversed by
successful arthroscopic repair. Higher degrees of muscular atrophy and fatty
infiltration preoperatively are associated with recurrence of the tear as well
as progression of fatty infiltration and muscular atrophy and an inferior
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.