Analysis of West Point View in Anterior Shoulder Instability

Abstract

Purpose : To evaluate the usefulness of the West point view, we investigated the osseous pathology of the glenoid rim associated with shoulder instability and estimate the inter-observer reliability. Materials and Methods : The West point views of sixty-seven patients with labral lesion confirmed by operation were mixed with those of thirty-three normal controls. Six observers independently reviewed the mixed radiographs and checked the lesion by identifying the glenoid erosion, bony defect, ectopic ossification and Hill-Sachs lesion. The incidence of osseous lesions suggest-ing instability was estimated. Sensitivity in the patient group, specificity in the normal control and inter-observer reliability were cal-culated to evaluate study susceptibility. Results : The sensitivity of 67 patients group was 81.8% on average (73-94%), the specificity of 33 member control group was 85.2% (82-94%). The most frequent finding was glenoid erosion, with an average of 54.7%, which providing a sensitive clue of shoul-der instability. Inter-observer reliability analyzed by using Kappa values showed significant agreement. (=0.1 significant level). Conclusion : The West point view is considered to be a reliable diagnostic modality for shoulder instability. The additional sophisticated method is indicated only when a discrepancy between physical examination and radiologic findings exists.