Transosseous repair with a cortical implant for greater tubercle cyst-related rotator cuff tear results in good clinical outcomes, but significant implant migration

Abstract

Purpose: To evaluate whether an arthroscopic transosseous technique (ATO) with cortical implants is effective for rotator cuff tear (RCT) repair in patients with cysts of the greater tuberosity (GTC).

Methods: Patients treated with the ATO technique between January 2013 and October 2017 were evaluated. Inclusion criteria were patients treated for both cyst-related and non-cyst-related RCTs and patients with a moderate-sized tear (1-3 cm) according to the DeOrio and Cofield classification. A total of 39 patients were separated into two groups: Group 1 (n = 16) patients with cyst-associated RCT, and Group 2 (n = 23) patients with no cyst. Implant pull-out and migration were evaluated radiologically on standard antero-posterior shoulder radiographs and rotator cuff re-tear was assessed on magnetic resonance images at the final follow-up examination. Group 1 patients were separated into two subgroups according to cyst size (cyst < 5 mm and cyst ≥ 5 mm) and subgroup analysis was performed. Clinical assessment was performed using a visual analog scale, the Constant score and Oxford shoulder score.

Results: The mean follow-up time was 33.7 ± 11.7 months. The mean cyst size was 5.4 ± 1.5 mm. There was no significant difference in re-tear rates between the cystic and non-cystic groups. The mean implant migration distance was 3.0 ± 2.2 mm in patients with a RCT -related cyst and 0.7 ± 0.8 mm in those without a cyst. A statistically significant difference was found between the groups (p = 0.002). There was no statistically significant difference between the groups in respect of clinical scores. No implant failure was observed.

Conclusion: The ATO method performed with a cortical implant in RCTs resulted in satisfactory recovery and clinical outcomes in the short to medium term with low failure rates. While no implant failures were observed, implant migration was associated with cyst presence. Therefore, judicious use is advocated in the choice of transosseous fixation for cyst-related RCTs and patients should be informed of the possibility of implant migration.

Level of evidence: III.

Keywords: Anterior greater tubercle cyst; Rotator cuff; Transosseous repair.