The evaluation of arthroscopic remplissage by high-resolution magnetic resonance imaging.

BACKGROUND

Arthroscopic remplissage is a novel procedure recently advocated for the treatment of large Hill-Sachs lesions with recurrent anterior glenohumeral instability. We have shown previously that infraspinatus tenodesis and Bankart repair reduce the risk of recurrent instability in high-risk patients. The ability to perform this procedure arthroscopically and without the need for bone grafting or an open approach makes this an appealing alternative to more traditional techniques.

PURPOSE

To evaluate and characterize the postoperative appearance of the remplissage procedure on high-resolution magnetic resonance imaging (MRI) and to correlate these findings to clinical outcome (Western Ontario Shoulder Instability [WOSI] score, range of motion).

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

In patients who had undergone arthroscopic remplissage for recurrent glenohumeral instability with large Hill-Sachs defects, images were acquired with a 3-T protocol (and reviewed by 2 musculoskeletal radiologists) with the shoulder in the abduction-external rotation (ABER) and neutral positions at the time of the latest clinical examination. Measured parameters included signal intensity of tissue within the prior defect, signal intensity of the residual infraspinatus, degree of fatty infiltrate and muscle atrophy as a percentage of fat signal versus muscle signal (Goutallier grade), presence of marrow edema, and number of anchors in the defect. Functional scores were obtained with the WOSI questionnaire, and comprehensive range of motion data were recorded with a goniometer.

RESULTS

In 11 patients with an average clinical follow-up of 18.0 months (range, 8.8-27.2 months), the average size of the Hill-Sachs deformity was 334.3 mm(3) (range, 93.6-825.1 mm(3)). The percentage of the deformity filled in with tendon was 75% to 100%, and the degree of atrophy was 0% to 25% for all patients studied. No defects were left unfilled. Two patients had granulation tissue filling the lesion, and 3 patients had fibrous tissue, while the rest of the patients had the MRI appearance of both granulation and fibrous tissue. Four of 9 patients had tendinopathy or partial tears of the residual infraspinatus tendon insertion, and 1 patient demonstrated residual bone marrow edema. The average number of anchors used was 1.4 (range, 1-3). The average WOSI score was 74.3% (range, 41.6%-99.2%), with an average external rotation loss of 5.8° (range, 0°-22°). One patient had recurrence of instability.

CONCLUSION

Our data suggest that there is evidence of tendon incorporation and fill into the Hill-Sachs defect following arthroscopic remplissage at 8 months and beyond. Although MRI findings did not correlate with the clinical findings, patients were satisfied with the procedure and demonstrated minimal loss of external rotation (average, 5.8°) at early follow-up.