Abstracts Posters SICOT-SOF meeting Gothenburg 2010 _2_

Poster
Topic: Arthroplasty - Shoulder
Abstract number: 25576
HUMERAL HEAD ANTERO-POSTERIOR SUBLUXATION ON CT SCAN:
VALIDATION AND COMPARISON OF 2 METHODS OF MEASUREMENT
Fanny CANET 1 , Dominique ROULEAU 1 , Jacob KIDDER 2 , Juan PONS DE
VILLANEUVA 3 , Savvas DYNAMIDIS 4 , Michael DEFRANCO 5 , Gilles WALCH 6
1 Hopital du Sacre-Coeur de Montreal, Montreal (CANADA), 2 The Orthopaedic Group,
Mobile (UNITED STATES), 3 Orthopaedic Surgery and Traumatology, Pamplona
(SPAIN), 4 Clinica Ortopedica, Genoa (ITALY), 5 Department of Orthopaedic Surgery
Lenox Hill Hospital, New york (UNITED STATES), 6 Centre Orthopaedique Santy,
Hopital Prive Jean Mermoz, Lyon (FRANCE)
Purpose: Humeral head static antero-posterior translation is important information in
the evaluation of osteo-arthritis, congenital deformity and instability. Two different
methods were used and compared in terms of absolute difference and reliability.
Methods: 115 patients with shoulder CT-scans were selected. The first method,
scapula method (SM), uses the scapula axis as a reference line. The second
method, mediatrice method (MM), used the mediatrice line, drawn as a perpendicular
line to glenoid joint surface passing in its middle. Results: The humeral head
subluxation was from 37% to 119% when the scapula method (SM) was used and
from 29% to 92% when the mediatrice method (MM) was used. For all three
evaluators there was a significant difference between the mean obtained by each
method, with the mediatrice method always reporting smaller percentages: 73.5%
(SD 15.1%) vs 59.7% (SD 11.2%) p