Marc-Olivier Gauci

A modification to the Walch classification of the glenoid in primary glenohumeral osteoarthritis using three-dimensional imaging

BACKGROUND Since Walch and colleagues originally classified glenoid morphology in the setting of glenohumeral osteoarthritis, several authors have reported varying levels of interobserver and intraobserver reliability. We propose several modifications to the Walch classification that we hypothesize will increase interobserver and intraobserver reliability. METHODS We propose the addition of the B3 and D glenoids and a more precise definition of the A2 glenoid. The B3 glenoid is monoconcave and worn preferentially in its posterior aspect, leading to pathologic retroversion of at least 15° or subluxation of 70%, or both. The D glenoid is defined by glenoid anteversion or anterior humeral head subluxation. The A2 glenoid has a line connecting the anterior and posterior native glenoid rims that transects the humeral head. Using 3-dimensional computed tomography glenoid reconstructions, 3 evaluators used the original Walch classification and the modified Walch classification to classify 129 nonconsecutive glenoids on 4 separate occasions. Reliabilities were assessed by calculating κ coefficients. RESULTS Interobserver reliabilities improved from an average of 0.391 (indicating fair agreement) using the original classification to an average of 0.703 (substantial agreement) using the modified classification. Intraobserver reliabilities improved from an average of 0.605 (moderate agreement) to an average of 0.882 (nearly perfect agreement). CONCLUSION When 3-dimensional glenoid reconstructions and the modified Walch classification described herein are used, improved interobserver and intraobserver reliabilities are obtained.

Clinical and radiologic outcomes of pyrocarbon radial head prosthesis: midterm results

BACKGROUND The modular pyrocarbon (MoPyC) radial head prosthesis (Tornier, Saint-Ismier, France) is a monoblock modular radial head prosthesis. This study assessed midterm outcomes after implantation of the prosthesis. MATERIALS A retrospective study was conducted of a consecutive cohort of 65 patients who underwent radial head replacement with the MoPyC prosthesis from January 2006 to April 2013. Indications were fractures, early or late failures from orthopedic or fixation treatments, and revisions after another implant. Patients were observed for >2 years for range of motion, pain, and stability; function by the Mayo Elbow Performance Score (total score, 100) and grip strength were assessed. Quality of stem implantation, bone resorption around the neck, and periprosthetic lucency were noted and quantified on radiographs. Capitellum shape and density as well as humeroulnar aspect (river delta sign) were evaluated. Complications and revision procedures were noted. RESULTS We evaluated 52 of 65 patients (mean follow-up, 46 ± 20 months; range, 24-108). The Mayo Elbow Performance Score was 96 ± 7; pain score, 42 ± 7/45; and motion score, 18 ± 2/20. Function and stability were excellent. Radiology revealed 92% of patients with cortical resorption around the neck without mechanical failure. Bone resorption was mostly anterior and lateral; it resolved within the first year and thereafter was stable. Eight patients underwent revision surgery for stiffness. No implant failures were noted. CONCLUSION Results of the MoPyC radial head prosthesis appear to be satisfactory. Bone resorption around the neck (stress shielding) is frequent and stable after 1 year and does not impair stem fixation. The MoPyC prosthesis appears to be a reliable solution for replacing the radial head.

Correlation between glenoid inclination and critical shoulder angle: a radiographic and computed tomography study

BACKGROUND Increased critical shoulder angles consist of both the acromial cover and glenoid inclination and have been found in patients with rotator cuff pathology. The purpose of this study was to determine the correlation of the critical shoulder angle and glenoid inclination and to determine the difference in glenoid inclination between patients with osteoarthritis and massive rotator cuff tears. METHODS The critical shoulder angle and glenoid inclination were measured on anteroposterior radiographs, and glenoid inclination was also measured on a validated 3-dimensional computer software program of 50 shoulders undergoing primary total shoulder arthroplasty. Twenty-five shoulders had osteoarthritis and A1 glenoids, as defined by the Walch classification, and were undergoing anatomic shoulder arthroplasty. The other 25 shoulders had massive rotator cuff tears and E0 glenoids, as defined by the Favard classification. The 2 groups were compared. RESULTS Critical shoulder angle and glenoid inclination were significantly correlated (R(2) = 0.7426, P < .001). Shoulders with massive rotator cuff tears (E0) demonstrated increased glenoid inclination measurements than shoulders with osteoarthritis (A1). As measured by the 3-dimensional software, the massive rotator cuff group had a glenoid inclination of 13.6° ± 4.3° and the osteoarthritis group had a glenoid inclination of 4.7° ± 5.6°. When measured by anteroposterior radiographs, the average glenoid inclination was 13.6° ± 4.6° in the massive rotator cuff group and was 7.6° ± 5.01° in the osteoarthritic group . CONCLUSION Glenoid inclination is linearly correlated with the critical shoulder angle and is significantly increased in patients with massive rotator cuff tears.

Massive irreparable rotator cuff tears: how to rebalance the cuff-deficient shoulder.

In its natural state, the shoulder is unbalanced in both the vertical and horizontal planes because the deltoid is stronger than the rotator cuff muscles and the internal rotator muscles are stronger than the external rotator muscles. With aging, this muscle imbalance can become worse, leading to tendon wear, irreversible fatty infiltration of the rotator cuff muscles, and upward migration of the humeral head. Most shoulders with tendon wear are functional and asymptomatic. A traumatic event (such as a fall onto the upper limb) can lead to rotator cuff tearing and a shoulder that becomes symptomatic and nonfunctional. Symptomatic massive irreparable rotator cuff tears present in one of four recognizable patterns depending on the muscular imbalance that occurs and the symptoms that are present: painful loss of active elevation, with conserved muscle balance; isolated loss of active elevation, with loss of vertical muscle balance; isolated loss of external rotation, with loss of horizontal muscle balance; and combined loss of elevation and external rotation, with loss of vertical and horizontal muscle balance. Assessing the plane of shoulder muscle imbalance is a key feature in the decision-making process. Classifying and understanding these tears allows surgeons to select the correct treatment (conservative measures, arthroscopic techniques, reverse shoulder arthroplasty, or tendon transfers) to restore shoulder balance and function.

Pyrocarbon interposition shoulder arthroplasty: preliminary results from a prospective multicenter study at 2 years of follow-up

BACKGROUND The concept of free interposition arthroplasty proved successful for small joints of the hand, wrist, and foot, particularly after the use of implants coated with pyrocarbon, which enhanced their tribologic and elastic properties. The present study reports preliminary outcomes of a pyrocarbon-coated interposition shoulder arthroplasty (PISA) implant. METHODS This was a prospective study of 67 consecutive patients who underwent shoulder PISA at 9 centers. The mean age at surgery was 51 years, with only 12 patients older than 60 years. The indications for surgery were primary glenohumeral arthritis in 42, avascular necrosis in 13, and secondary arthritis in 12 patients. RESULTS Revision surgery was performed in 7 patients (10.4%), 2 (3.0%) were lost to follow-up, and the outcome assessments were incomplete in 3 (4.4%). This left 55 patients, aged 49.3 ± 12.0 years, with complete outcomes assessments at a mean follow-up of 26.8 ± 3.4 months. The Constant score improved from 34.1 ± 15.1 preoperatively to 66.1 ± 19.7 postoperatively. The radiographic findings revealed erosion in 6 glenoids and thinning of 3 humeral tuberosities. CONCLUSION In a cohort of young arthritic patients, PISA renders clinical scores and implant survival comparable to those of hemishoulder arthroplasty but remain inferior to those results reported for total shoulder arthroplasty. The study enabled identification of contraindications and potential causes of failure that wererelated to the concept of free interposition and smaller radius of curvature of the sphere. Until long-term results are available, this type of innovative implant should remain to be tested in a few specialized shoulder centers.

Angled BIO-RSA (bony-increased offset-reverse shoulder arthroplasty): a solution for the management of glenoid bone loss and erosion.

BACKGROUND Glenoid deficiency and erosion (excessive retroversion/inclination) must be corrected in reverse shoulder arthroplasty (RSA) to avoid prosthetic notching or instability and to maximize function, range of motion, and prosthesis longevity. This study reports the results of RSA with an angled, autologous glenoid graft harvested from the humerus (angled BIO-RSA). METHODS A trapezoidal bone graft, harvested from the humeral head and fixed with a long-post baseplate and screws, was used to compensate for residual glenoid bone loss/erosion. For simple to moderate (<25°) glenoid defects, standardized instrumentation combined with some eccentric reaming (<15°) was used to reconstruct the glenoid and obtain neutral implant alignment. For severe (>25°) and complex (multiplanar) glenoid bone defects, patient-specific grafts and guides were used after 3-dimensional planning. Patients were reviewed with minimum 2 years of follow-up. Mean follow-up was 36 months (range, 24-81 months). Preoperative and postoperative measurements of inclination and version were performed in the plane of the scapula on computed tomography images. RESULTS The study included 54 patients (41 women, 13 men; mean 73 years old). Fifteen patients had combined vertical and horizontal glenoid bone deficiency. Among E2/E3 glenoids, inclination improved from 37° (range, 14° to 84°) to 10.2° (range -28° to 36°, P < .001). Among B2/C glenoids, retroversion improved from -21° (range, -49° to 0°) to -10.6° (-32° to 4°, P = .06). Complete radiographic incorporation of the graft occurred in 94% (51 of 54). Complications included infection in 1 and clinical aseptic baseplate loosening in 2. Mild notching occurred in 25% (13 of 51) of patients. Constant-Murley and Subjective Shoulder Value assessments increased from 31 to 68 and from 30% to 83%, respectively (P < .001). CONCLUSION Angled BIO-RSA predictably corrects glenoid deficiency, including severe (>25°) multiplanar deformity. Graft incorporation is predictable. Advantages of using an autograftharvested in situ include bone stock augmentation, lateralization, low donor-site morbidity, low relative cost, and flexibility needed to simultaneously correct posterior and superior glenoid defects.