The Cartilage Wear Index: a new evaluation method to improve patient selection in surgical treatment of recurrent posterior glenohumeral instability

Albert Ferrando; Juan Aguilar; Maria Valencia; Ulrike Novo; Emilio Calvo

doi:10.1016/j.jseint.2021.12.010

The Cartilage Wear Index: a new evaluation method to improve patient selection in surgical treatment of recurrent posterior glenohumeral instability

JSES Int. 2022 Jan 29;6(3):368-373. doi: 10.1016/j.jseint.2021.12.010. eCollection 2022 May.

Authors

Albert Ferrando¹, Juan Aguilar², Maria Valencia², Ulrike Novo³, Emilio Calvo²

Affiliations

¹ Shoulder Unit, Hospital Universitari Sant Joan de Reus, Reus, Spain.
² Shoulder and Elbow Unit, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain.
³ Musculoskeletal radiology Department, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain.

Abstract

Background: The purpose of this study was to validate glenoid cartilage lesions as a negative prognostic factor and to define a new image-based preoperative evaluation method to identify surgical candidates for arthroscopic labral refixation with suture anchors in posterior shoulder instability.

Methods: Twenty-six patients who underwent arthroscopic posterior labral repair for shoulder instability were evaluated. Only patients with structural dynamic posterior instability were included. We evaluated on preoperative magnetic resonance arthrogram: glenoid version, humeral head subluxation, type of capsular insertion, and the cartilage lesions using the new Cartilage Wear Index (CWI). Two subgroups were analyzed with regard to the preoperative CWI and shoulder outcome scores: Single Assessment Numerical Evaluation (SANE) and Western Ontario Shoulder Instability Index (WOSI).

Results: The median age at operation was 28 (interquartile range = 21-33) years. Median overall postoperative outcome assessment demonstrated a SANE of 90 and a WOSI of 385. The median CWI was 1.02. Subgroup analysis revealed worse median WOSI and SANE scores in patients with a CWI >1.02 and a strong correlation between a high preoperative CWI and a higher postoperative WOSI score (R = 0.58; P = .038).

Conclusion: The CWI can be useful to identify patients who might obtain better outcomes when treated with arthroscopic labral repair in posterior shoulder instability.

Keywords: Cartilage Wear Index; Cartilage wear; Glenoid retroversion; Humeral head subluxation; Posterior instability; Shoulder; Structural dynamic.