Figure 16.1
Three-dimensional reconstruction of routine preoperative CT imaging. With advanced imaging, the superior bone loss can be better quantified and utilized for preoperative planning
Diagnosis/Assessment
The patient’s history, physical, and radiographic findings are consistent with the diagnosis of rotator cuff arthropathy. While there are many options for patients with a massive rotator cuff tear, this patient had notable superior migration with glenohumeral arthritis, making him an excellent candidate for reverse total shoulder arthroplasty. The uncontained defect of the superior glenoid is discussed as part of the patient’s preoperative planning, and in this case it was determined that the patient may require intraoperative grafting to optimize glenoid positioning and fixation.
Management
A routine deltopectoral approach was performed. The subdeltoid, subacromial, and subcoracoid spaces were released. A subscapularis tendon peel off of the lesser tuberosity was performed and the appropriate humeral head cut was made. A standard circumferential release was completed along the rim of the glenoid, taking care to protect the axillary nerve. In this case, the glenoid revealed the expected uncontained superior defect.
Using the CT imaging and the visualized inferior glenoid as a guide, the 2.5 mm drill bit was used to drill bicortical until the tip exited the anterior scapula (Fig. 16.2). The hole was measured to assure an adequate depth of greater than 25 mm. Along the same trajectory as the drill bit, a 6.5 mm guide tap was placed (Fig. 16.3). This was used as a guide for reaming. The native inferior glenoid was reamed down to cortical bone, while the superior defect was left untouched (Fig. 16.4). The surface bone of the defect can be prepared with a motorized burr to provide a roughened surface to receive the graft.
Figure 16.2
Right shoulder with drill bit placed in the center of the glenoid
Figure 16.3
The tap is inserted along the same trajectory as the drill bit
Figure 16.4
The inferior portion of the glenoid is reamed to bleeding bone. The superior portion with significant bone loss is noted and used as a guide to shape autograft from the humeral head cut
On the back table, the humeral head was prepared and shaped to match the defect. The cartilaginous surface serves as the outer portion of the glenoid, while the remainder of the head is prepared to later receive the baseplate. First, the graft is fixed to the native glenoid using multiple Kirschner wires that will not obstruct placement of the reamer (Fig. 16.5). Once the autograft is securely fixed, it was reamed to the same depth as the previously reamed native glenoid (Fig. 16.6). The baseplate was then placed, the wires removed, and peripheral screws placed (Fig. 16.7). A glenosphere that was hooded to cover more of the baseplate was impacted directly onto the graft to enhance both fixation and compression (Fig. 16.8).
