Comparative study of open and arthroscopic coracoid transfer for shoulder anterior instability (Latarjet)-computed tomography evaluation at a short term follow-up. Part II.

PURPOSE AND HYPOTHESIS: The aim of this study was to evaluate and to compare the radiological parameters after arthroscopic and open Latarjet technique via evaluation of computed tomography (CT) scans. Our hypothesis was that the radiological results after arthroscopic stabilisation remained in the proximity of those results achieved after open stabilisation.
MATERIAL AND METHODS: CT scan evaluation results of patients after primary Latarjet procedure were analysed. Patients operated on between 2006 and 2011 using an open technique composed the OPEN group and patients operated on arthroscopically between 2011 and 2013 composed the ARTHRO group. Forty-three out of 55 shoulders (78.2%) in OPEN and 62 out of 64 shoulders (95.3%) in ARTHRO were available for CT scan evaluation. The average age at surgery was 28 years in OPEN and 26 years in ARTHRO. The mean follow-up was 54.2 months in OPEN and 23.4 months in ARTHRO. CT scan evaluation was used to assess graft fusion and osteolysis. Bone block position and screw orientation were assessed in the axial and the sagittal views. The subscapularis muscle fatty infiltration was evaluated according to Goutallier classification.
RESULTS: The non-union rate was significantly higher in OPEN than in ARTHRO: 5 (11.9%) versus 1 (1.7%) (p < 0.05). The total graft osteolysis was significantly higher in the OPEN group: five cases (11.9%) versus zero in ARTHRO (p < 0.05). Graft fracture incidence was comparable in both groups: in two patients in ARTHRO (3.3%) and one case (2.4%) in the OPEN group (p > 0.05). These results should be evaluated very carefully due to significant difference in the follow-up of both groups. A significantly higher rate of partial graft osteolysis at the level of the superior screw was reported in ARTHRO with 32 patients (53.3%) versus 10 (23.8%) in OPEN (p < 0.05). In the axial view, 78.4% of patients in ARTHRO and 80.5% in OPEN had the coracoid bone block in an acceptable position (between 4 mm medially and 2 mm laterally). In the sagittal plane, the bone block was in an acceptable position between 2 and 5 o'clock in 86.7% of patients in ARTHRO and 90.2% in OPEN (p > 0.05). However, in the position between 3 and 5 o'clock there were 56.7% of the grafts in ARTHRO versus 87.8% in OPEN (p < 0.05). The screws were more parallel to the glenoid surface in ARTHRO-the angles were 12.3° for the inferior screw and 12.6° for the superior one. These angles in the OPEN group were respectively 15° and 17° (p < 0.05 and for the superior screw). There was no significant difference in the presence of fatty infiltration of the subscapularis muscle.
CONCLUSIONS: Arthroscopic Latarjet stabilisation showed satisfactory radiographic results, comparable to the open procedure, however the short-term follow-up can bias this evaluation. Graft healing rate was very high in the arthroscopic technique, but yet osteolysis of the superior part of the graft and more superior graft position in the sagittal view were significantly different when compared to the open technique. The screw position was slightly more parallel to the glenoid via the arthroscopic technique. We recommend both further investigation and development of the arthroscopic technique. LEVEL OF EVIDENCE: III.