Preoperative Planning for Anatomic Total Shoulder Arthroplasty

Abstract

The success of total shoulder arthroplasty is dependent on both proper patient selection and restoration of the native anatomy. After proper patient selection, preoperative planning is essential to select implants that will allow the surgeon to properly restore soft-tissue tension and correct for deformity. Although it is possible to template implants with plain radiographs, these do not allow accurate measurements of the complex three-dimensional anatomy of the glenohumeral joint. CT can be used to further examine version of the glenoid and humerus, as well as humeral head subluxation. Three-dimensional reconstructions also allow for virtual implantation, resulting in a more reliable prediction of implant appearance. Commercial software is available that calculates parameters such as version; however, these have been shown to have variability when compared with measurements obtained by surgeons. Patient-specific instrumentation can also be obtained based on preoperative measurements; however, although it allowed for improved measurements when compared with two-dimensional imaging, there has been no difference in version error, inclination error, or positional offset of the glenoid implant when comparing patient-specific instrumentation with standard instrumentation. Intraoperative navigation can also be used to give real-time feedback on implant positioning; however, additional studies are needed to fully evaluate its benefit.

Custom, 3-Dimensional Patient-Specific Instrumentation in Anatomic Total Shoulder Arthroplasty: Part 1—Preoperative Assessment, Preoperative Planning, and Guide Design

“…In the surgical management of glenohumeral OA, the advent of 3D CT reconstruction has allowed for more advanced analysis of patients’ native glenoid version and inclination that, unlike intraoperative assessment, is not biased by patient positioning. 23 , 24 Several commercial software programs exist for automatic segmentation of CT scans to identify the landmarks of the glenoid and humerus independently, in addition to allowing for virtual planning of implants and assessment of central peg perforation risk. 25 , 26 To assess the accuracy of these products, Erickson et al.…”

“…Whether more consistent and accurate glenoid placement seen with PSI confers improved long-term clinical outcomes and implant survivorship has yet to be determined and ultimately will require further investigation. 3 , 24 As preoperative technology for anatomic and reverse shoulder arthroplasty continues to expand, the use of PSI and implant design must continue to be scrutinized and appropriately adopted by surgeons.…”

Accuracy and Reliability of Computerized Surgical Planning Software in Anatomic Total Shoulder Arthroplasty

“…Anatomic total shoulder arthroplasty (aTSA) is a well-accepted treatment option for advanced arthritis of the glenohumeral joint with an intact rotator cuff following failure of non-surgical management [ 1 ]. The implementation of preoperative templating and patient-specific instruments have grown in popularity with the goal of improving implant positioning and, thereby, patient-reported outcomes [ 2 ].…”

“…The implementation of preoperative templating and patient-specific instruments have grown in popularity with the goal of improving implant positioning and, thereby, patient-reported outcomes [ 2 ]. Traditionally, plain radiographs and 2D CT scans were the main imaging modalities used for preoperative assessment of glenoid wear, version, size, and inclination, in addition to humeral head size and bone quality [ 1 ]. Computerized planning programs using computerized tomography (CT) with 3D modeling have been recently developed for a more accurate assessment of these parameters and to provide automated values for glenoid measurement indices [ 3 ].…”

“…The glenoid version can be restored by eccentric reaming, use of bone graft, or placement of augmented glenoid components [ 8 ]. Choosing the appropriate sizes of different components of TSA can help minimize the risk of intraoperative fractures, postoperative instability, overstuffing of the joint, and impingement on the rotator cuff [ 1 ]. Moreover, recent studies have shown a significant reduction in the number and cost of sterilized trays when preoperative planning was applied [ 9 ].…”