Isolated labral repair in patients with symptomatic paralabral cysts leads to significant pain relief with cyst resolution within 2-3 months and secondary muscle pathology (ie, edema, atrophy and fatty infiltration) may be partially or completely reversed.
Paralabral cysts emanating from posterosuperior labral tears may compress the
suprascapular nerve and induce neuropathy. This study prospectively assessed patients with labral tears and symptomatic tears treated with labral repair and no cyst decompression. Pain relief, time to cyst resolution, reversibility of muscular edema, atrophy, fatty infiltration, and bone erosion were evaluated.
Material And Method
Forty-seven patients with a posterosuperior labral tear and a symptomatic cyst were treated with arthroscopic debridement of the glenoid rim and labral repair with suture anchors. All patients had MRI performed the day before surgery, at six and twelve weeks postoperative or until cyst resolution. In addition, fifteen patients had MRI the first postoperative day and at two weeks. The median cyst size was 6.8 cm³ (range, 2.1-88.9; standard deviation (SD), 18.3 cm³). Preoperatively, twenty patients (43%) had muscular atrophy and radiological edema on MRI, eight had varying degrees of fatty infiltration, and three patients presented scapular erosion caused by cyst compression.
The mean time to cyst resolution and regression of muscular edema was 11 weeks(range, 3-20; SD 8.8 weeks) and 14 weeks (range, 3-52; SD 10.6 weeks), respectively. Preoperative fatty infiltration grade I and II of the supraspinatus and infraspinatus muscles was
reduced in two patients. Bony erosions remodeled after cyst resolution. Mean pain ratings (1-10 scale) improved from 7.7 (SD, 1.8) to 1.3 (SD, 1.3; 95% confidence interval of difference, 5.5-6-8; p < .001.
Labral repair without cyst decompression leads to significant pain relief with cyst resolution within 2-3 months in the majority of the patients. Patients with muscular edema on MRI preoperatively have a good prognosis for regaining normal muscle. In a few cases, fatty infiltration seems to be reversible, but it may take a long time. Scapular bone erosion caused by cyst compression, may be reversed after cyst resolution, eliminating the need for bone grafting.