Abstract
Bone loss of the glenoid may preclude performing a glenoid replacement. In this setting a hemiarthroplasty will be the best option available. While the debate of hemiarthroplasty versus total shoulder replacement (TSR) continues, most would prefer to replace the glenoid if there is gross loss of articular cartilage and the cuff is intact or repairable. In order to ensure a lasting glenoid component adequate bone stock is critical. Neer noted in 463 TSR’s that the glenoid was able to be inserted in all but 2 patients. Bone grafting was necessary in 20 patients. Hill and Norris reported on 17 patients with bone grafting for glenoid replacement and found that only 53% of their patients had satisfactory results and 29% had revisions – often early.
In order to evaluate the adequacy of the glenoid satisfactorily, true AP and axillary views are important. Version angles can be difficult to evaluate on a standard axillary view, if rotated – so a CT scan will be useful. Defects may be central (cavitary) or segmental. Posterior lesions are common in osteoarthritis and central lesions in rheumatoid arthritis or after failure of a prior glenoid.
Management will be determined by the degree of bone loss. In glenoid central defects, bone grafting with morselised bone with possibly a fascial graft will fill the defect and present future options. Segmental or asymmetrical defects are managed either by asymmetrical reaming or bone grafting at the site combined with glenoid insertion. If gross loss of bone is present posteriorly the bone can be reamed and the humeral head inserted with decreased retroversion. If the glenoid has asymmetrical wear then reaming to a smooth glenoid will improve the results of a hemiarthroplasty as noted by Bigliani.
Humeral bone loss such as a removed tuberosity will create problems for cuff reattachment that may require allografts.
In reconstructing the humerus, restoration of length is critical to avoid inferior instability. This may require a custom prosthesis and an attempt to restore bone stock.
The abstracts were prepared by Mrs Dorothy L. Granchi, Course Coordinator. Correspondence should be addressed to her at PMB 295, 8000 Plaza Boulevard, Mentor, Ohio 44060, USA.
