Long-term prevalence and impact of glenohumeral osteoarthritis after Latarjet-Patte procedure for anterior instability.

Introduction: The Latarjet procedure provides satisfactory functional results, with low rates of recurrence. It is, however, sometimes claimed to induce osteoarthritis due to the positioning of the bone-block and hardware. The aims of the present study were to assess the long-term prevalence of osteoarthritis following the procedure, to determine risk factors and assess clinical impact. The study hypothesis was that osteoarthritis risk can be reduced by good bone-block positioning. The secondary objective was to assess long-term recurrence of instability.

Materials And Methods: Out of a cohort of 102 patients (106 shoulders) operated on between 1984 and 1998, 77 had complete radiology files for analysis in a previous study published in 2003. Forty-four of these patients were seen again for clinical and radiological assessment at a mean 22 years' follow-up, to be compared to results previously reported at 8 years. Clinical assessment comprised range of motion and Constant and Walch-Duplay scores. X-rays were taken systematically to determine Samilson osteoarthritis stage; 31 patients also underwent CT.

Results: In the 44 patients, the rate of osteoarthritis was 34.1%. 90.9% of patients were satisfied. Mean Constant score was 83.5±14 and mean Walch-Duplay score was 71.6±23.4. Advanced age at surgery and at assessment, length of follow-up and age >30 years at first episode of instability were the main factors for onset of osteoarthritis, independently of surgery. Lateral bone-block overhang correlated with onset of osteoarthritis: 71.4%, versus 16.7% in medial or flush bone-block (p=0.0004). Humeral notch, glenoid bone defect and number of preoperative episodes of instability were unrelated to onset of osteoarthritis. Lateral bone-block overhang was the only risk factor related to surgery. The clinical impact of the osteoarthritis was significant only in advanced stages (Samilson 3 and 4).

Conclusion: Lateral bone-block overhang was the only surgical risk factor for osteoarthritis in the long-term. Strict coracoid positioning is therefore essential, and could be facilitated by specific instrumentation and by arthroscopy.

Level Of Evidence: IV; retrospective study.