2015 ISAKOS Biennial Congress Paper #0

Analysis of Bipolar Bone defects Pattern in Anterior Shoulder Instability

Maristella Francesca Saccomanno, MD, PhD, Brescia ITALY
Francesco DeFilippo, MD, Brescia ITALY
Marcello Motta, MD, Brescia ITALY
Marco Adriani, MD, Brescia, Brescia ITALY
Mac Donald Tedah Djemetio, MD, Brescia ITALY
Giuseppe Milano, Prof., Brescia, BS ITALY
university of Brescia, Brescia, Italy, ITALY

FDA Status Not Applicable

Summary: The predictive value of the “on-track/off-track” concept has been recently called into question by the introduction of the “Hill–Sachs interval to glenoid track width ratio” (H/G ratio), which can predict an increased risk of recurrent instability after arthroscopic Bankart repair

Abstract:

Background

The predictive value of the “on-track/off-track” concept has been recently called into question by the introduction of a new threshold between peripheral and central on-track lesions: the so-called “Hill–Sachs interval to glenoid track width ratio” (H/G ratio). The aim of the present study was to analyze which pattern of bipolar lesion increases the risk of recurrent anterior gleno-humeral instability after arthroscopic Bankart repair.

Methods

A retrospective study was conducted. Patients affected by recurrent anterior gleno-humeral instability who underwent arthroscopic Bankart repair with a minimum of 12 months follow-up were included. A preoperative computed tomography (CT) scan was performed in all patients. Only patients with on-track bipolar defects were included. Subsequently, three-dimensional computer-based reconstruction of the Hill-Sachs and glenoid bone defect were performed using a dedicated software in order to obtain the H/G ratio following the formula: Hill Sachs interval/glenoid track width. Included patients were than divided into two groups according to the H/G ratio: group 1, patients with H/G ratio< 0.7; group 2, patients with H/G ratio > 0.7. The primary outcome was recurrent instability after surgery. Secondary outcomes were: Quick-DASH, ASES and WOSI score.
Comparison between groups was performed by use of chi-square test for categorical variables and unpaired t-test for discrete variables. Significance was set at p<0.5.

Results

The study included 36 males and 4 females. Mean age (+ SD) of patients was 25.7 ± 7.6 years. Each group was composed of 20 patients. Mean follow-up in group 1 was 54.6 + 30.68; while mean follow up in group 2 was 51 + 34.65. Comparison between groups did not show significant differences nor for baseline characteristics, neither at follow-up. Two recurrent instabilities occurred in group 2 (H/G ratio >0.7) (p<0.147).

Conclusions

Although two recurrent instabilities occurred only in group two, no significant differences could be found between central and peripheral track lesions.