We are very proud to share Dr. Bruno Gobbato‘s case study, “Surface Glenoid Area in Latarjet-Patte and Congruent Arc in Virtual Model”, presented in a poster at the AAOS Annual Meeting 2016. The 3D models of the shoulder were generated from computed tomography scans, using the PeekMed software to plan the surgery.
The Latarjet procedure for treating anterior shoulder instability is a well known technique with excellent results. The correct positioning of the coracoid process to the medial border of the glenoid is crucial for the results.
There are two different ways to fix the graft, the standard Latarjet-Patte and Congruent Arc.
The purpose of this study is to evaluate the percentage of increase in surface area of the glenoid and the graft’s contact area in a virtual model.
3D models of the shoulder were generated from computed tomography scans in 10 patients with recurrent anterior shoulder instability with glenoid bone loss and Instability Severity Index Score (ISIS) greater than 6. Using the PeekMed software, the surgery was planned performing the coracoid osteotomy and placing the coracoid graft along the medial glenoid border.
Two techniques were used. Standard Latarjet-Patte (SL) and Concruent Arc (CA).
The surface areas of the injured glenoid, SL, CA, graft contact area and screw location were measured.
Results are presented in mm2. A one-way analysis of variance and T-test was used for the following variables: injured glenoid area, SL glenoid area, CA, graft contact, percentage increase area.
The mean injured glenoid area was 792. Standard Latarjet-Patte 1007 and Congruent Arc 1065.
CA (34%) technique increased statistically(p<0.05) the percentage glenoid area compared to SL (27%).
Coracoid graft contact area to the anterior border of the glenoid was 304mm2 in SL and 215mm in CA (p<0.05).
The graft’s width for screw drilling was 15mm in SL and 10mm in CA (p<0.05).
Both Standard Latarjet-Patte and Congruent Arc increased 30% glenoid surfasse area.
Total area was similar in both techniques (SL 1007, CA 1065) but CA has increased the percentage glenoid area compared to SL.
The graft’s contact area is important for healing and a smaller width can undermine the location of the screws leading to fracture. SL had a greater contact area and graft width compared to CA.
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