We hypothesised that a large acromial cover with
an upwardly tilted glenoid fossa would be associated with degenerative
rotator cuff tears (RCTs), and conversely, that a short acromion
with an inferiorly inclined glenoid would be associated with glenohumeral
osteoarthritis (OA). This hypothesis was tested using a new radiological parameter,
the critical shoulder angle (CSA), which combines the measurements
of inclination of the glenoid and the lateral extension of the acromion
(the acromion index). The CSA was measured on standardised radiographs of three groups:
1) a control group of 94 asymptomatic shoulders with normal rotator
cuffs and no OA; 2) a group of 102 shoulders with MRI-documented
full-thickness RCTs without OA; and 3) a group of 102 shoulders
with primary OA and no RCTs noted during total shoulder replacement.
The mean CSA was 33.1° (26.8° to 38.6°) in the control group, 38.0°
(29.5° to 43.5°) in the RCT group and 28.1° (18.6° to 35.8°) in
the OA group. Of patients with a CSA >
35°, 84% were in the RCT
group and of those with a CSA <
30°, 93% were in the OA group. We therefore concluded that primary glenohumeral OA is associated
with significantly smaller degenerative RCTs with significantly
larger CSAs than asymptomatic shoulders without these pathologies.
These findings suggest that individual quantitative anatomy may
imply biomechanics that are likely to induce specific types of degenerative
joint disorders. Cite this article:
Treatment strategies for the management of proximal humeral fractures are assisted by an understanding of the fracture morphology and, in particular, the viability of the humeral head. Although widely accepted, the AO and Neer classification systems show poor interobserver reproducibility and generally do not provide a basis to guide treatment. The aim of this study was to compare the interobserver and intraobserver reliability of a new classification system with the AO and Neer classifications and review its usefulness as a guide to management. Hertel described a comprehensive binary (Lego) classification system, which defines fracture planes and parts, as well as incorporating calcar length, attachment and angulation. This facilitates predicting humeral head ischemia; however the sequential numerical form of the classification makes it complex and prone to categorisation error. Sandow has extended this to a more descriptive system by naming proximal humeral parts (H-head, G-greater tuberosity, L-lesser tuberosity, S-shaft), recording the fracture plane and optionally incorporating calcar length and head angulation or displacement. 50 proximal humeral fractures in 50 patients treated at the Department of Orthopaedics and Trauma, Royal Adelaide Hospital, were identified from the period of July 2007 to January 2008. All fractures of the proximal humerus were examined using AP, lateral and axial radiographs. Three independent reviewers classified the fractures using the AO, Neer and “HGLS Classification”. The findings were analysed specifically for intra/interobserver correlation and the indications for humeral head viability. The median age of patients was 72 (range 50 to 85). Based on the interobserver correlation analysis, the AO and Neer Classification systems were graded as poor. The ‘HGLS’ Classification showed good interobserver agreement for all three examiners and more consistently provided guidelines for management based on humeral head viability. While the parts system of Neer can still provide a general impression of the fracture form, the “HGLS classification” for proximal humeral fractures provided a more precise description of the fracture pattern which has important prognostic and therapeutic implications. It is quick to apply and easy to use as it does not require memorisation of a numerical classification and can help to understand fracture patterns and thus aid planning of a reduction and fixation strategy. Good interobserver correlation makes it a useful tool for communication between surgeons.
We compared six patients with a mean age of 70 years (49 to 80) with severe bilateral, painful glenohumeral joint destruction who underwent a single-stage bilateral total shoulder replacement, with eight patients of mean age 61 years (22 to 89) who underwent bilateral total shoulder replacement in two stages, at a mean interval of 18 months (6 to 43). The overall function, pain and strength improved significantly in both groups. The subjective shoulder value, relative Constant score, active external rotation and the strength were improved significantly more in the single-stage group. Active elevation, abduction and overall function improved, significantly more in the single-stage group. Both the total duration of hospitalisation and the time off work per shoulder were substantially shorter in the single-stage group. The overall rate of complication was lower in the single-stage group. Our findings indicated that single-stage bilateral total shoulder replacement yielded significantly better clinical results with shorter hospitalisation and rehabilitation than staged replacement, and was not associated with any increase in complications.