Assessing glenoid version is important for a successful total shoulder arthroplasty. Glenoid version is defined as the orientation of the glenoid cavity in relation to a plane perpendicular to the scapula body. Glenoid revision averages between 1 to 2 degrees of retroversion and varies between race and sex. In general glenoid retroversion is overestimated by 6.5 degrees on plain radiographs. Furthermore standard axial 2D CT is aligned to the patient's body and not aligned to the scapula. Therefore 3D reconstructions generated from standard CT allows for analysis of the scapula as a free body and correct version measurements can be made unaffected by positioning. If you add a computer modeling coordinate system in which implants can be added, then computer simulation surgery can be performed. This is important because implanting a glenoid component in excessive retroversion leads to increased stress at the glenoid component and cement mantle and decreased contact with the humeral component. Also excessive reaming of the glenoid surface to neutral retroversion can lead to excessive bone loss and penetration of the glenoid vault by either the pegs or the keel of the glenoid component.

Shoulder arthroplasty is increasing and can lead to excellent results for the proper indicators. We will review cases of primary shoulder arthroplasty as well as complex cases. Furthermore we will present complications of shoulder arthroplasty and how they are successfully managed.

Radiolucent lines in total shoulder arthroplasty around the glenoid component are not uncommon in post-operative x-rays and the incidence varies. A certain percentage progress and as the lines enlarge can lead to component loosening. One study reported a 9% incidence at 2 years and 27% incidence at 5 years. A recent long term study (15 to 20 years) reported a 73% incidence. Radiolucent lines can be caused by anatomy (posterior glenoid wear) or pathology (inflammatory arthritis) as well as technical factors such as glenoid implant design (metal back) and improper implantation techniques where the prosthesis is not fully seated or cement is used to fill a defect. Every attempt should be made to avoid lucent lines. Minimal bone should be removed from the glenoid vault and a pressure injection type of insertion is helpful in getting the cement into the cancellous bone. Furthermore a peg type of glenoid implant rather than a keel type is preferred as this has been associated with a lower incidence of radiolucent lines.

Charles Neer designed his original prosthesis in 1951. It was made of cast cobalt chrome alloy and was only press-fit. There was not any significant loosening in his original series, but patients complained of easy fatigability. Neer attributed this to glenoid issues and that a glenoid replacement would eliminate this. The Neer II system was introduced with a glenoid component in 1973 and first generation cement fixation was used. Cemented glenoid components have been found to have radiolucencies in 26–100% with progressive radiolucencies in 0–36%. High rates of lucencies raise issues of fixation. Cementless glenoid components have been found to have fewer lucencies but require metal backing leading to higher stress concentrations. Greater bone stock is required and there are the problems of polyethylene dissociation and screw breakage prior to bony ingrowth. Rodosky reported a higher failure rate with a cementless design versus cemented glenoids. With humeral fixation, symptomatic loosening is not a problem with cement or coated press-fit fixation. Neer’s and Cofield’s long-term outcome studies with cemented stems have shown the incidence of humeral loosening to be low (0–2.5%). Cementing provides immediate fixation with the ability to place components in shafts with poor proximal bone stock. A recent literature review noted radiographic evidence of loosening in 12% of uncemented humeral components with only 0.3% of the patients having symptomatic loosening. Fixation of humeral components should be based on bone quality, patient age, prosthetic design and surgeon preference.

Prosthetic replacement of the humeral head for fracture remains an operative challenge to even the most experienced orthopaedic surgeon. Although most fractures of the proximal humerus are minimally displaced and treated conservatively, more complex fractures require operative intervention. In this respect, the four-part proximal humerus fracture and fracture-dislocation have been difficult to evaluate and manage. Results from conservative treatment have been consistently unsatisfactory while results from surgery have been more variable with some series reporting satisfactory results.

Treatment options for four-part fractures and fracturedislocations of the proximal humerus fractures include non-operative management, open reduction internal fixation, and humeral head replacement. Because of the poor results with non-operative, resection arthroplasty, and internal fixation, Neer in 1951 introduced prosthetic arthroplasty with tuberosity reconstruction for these complex fractures. Many reports in the literature have documented the successful results of this procedure. In our series of 65 shoulders there were 82% satisfactory results, 97% pain relief, and 85% good functional results. Therefore, prosthetic replacement of acute displaced fractures is technically demanding but offers a predictive result of a pain-free shoulder and functional motion through aggressive rehabilitation. Our goals in this video are to provide stepwise, comprehensive information on the techniques and guidelines for humeral head replacement in the treatment of complex proximal humerus fractures. Careful preoperative planning, patient evaluation, imaging, meticulous operative techniques, and a closely supervised rehabilitation program are necessary to produce a successful functional shoulder after prosthetic reconstruction.