The intra- and inter-observer reliability of the CT-scan based X index to quantify glenoid bone loss in chronic anterior shoulder instability and its impact on decision making.

PURPOSE: The X index is a measure of the antero-inferior glenoid bone loss on unilateral 2D CT-scans in the preoperative analysis of chronic anterior shoulder instability. Recurrence rate was shown to be higher after stabilization surgery if X index is superior or equal to 0.4. The objective of this study was to assess the intra- and inter-observer reliability of the X index. METHODS: Sixty patients with an X index ≥0.4 were included retrospectively. The X index was measured twice by two independent evaluators, 15 days apart. The measurement was performed on a unilateral 2D CT-scan by dividing the length of the antero-inferior glenoid defect over the maximal antero-posterior diameter of the glenoid. Reliability of X index was assessed with intra-class correlation coefficient (ICC, ρ). Two points were added to the ISIS calculation if its glenoid criterion was "zero" and we compared this modified score to the original one. RESULTS: The intra-observer reliability of the X index measurement was "excellent" (ρ = 0.95 ± 0.01, p < 0.0001) while the inter-observer reliability was "good" (ρ = 0.59 ± 0.08, p < 0.0001). In patients with a glenoid bone loss visualized by the X index, 48.3 % had a negative sclerotic glenoid line sign. This proportion significantly decreased with the augmentation of the X index, p = 0.02. The average original ISIS score was 3.4 ± 1.9 and became 4.3 ± 1.7 (p < 0.00001) when the X index was incorporated. CONCLUSIONS: The X index is a reliable and simple unilateral 2D CT-scan measurement. AP shoulder radiographs significantly underestimated glenoid bony lesions.

Routine one-stage exchange for chronic infection after total hip replacement.

PURPOSE: We hypothesized that a routine one-stage exchange for treatment of chronically infected total hip replacement (THR) will lead to (1) a higher rate of infection recurrence and (2) a poorer hip outcome than the published rates after two-stage exchange. METHODS: Sixty-five cases have been treated consecutively with one-stage exchange. All patients have been followed for a period of three to six years or until death or infection recurrence. RESULTS: The five-year rate for infection recurrence was 16%. The five-year survival rate for recurrence of the index infection was 8%. Forty-two percent of the hips had a good or excellent PMA score, and 46% a good or excellent OH score. CONCLUSIONS: Routine one-stage exchange was not associated with a higher recurrence rate and a poorer hip function than previously published series of two-stage exchange. Therefore, there is little support to choose two-stage exchange as the routine treatment for management of chronically infected THR.