Patient-specific instrumentation for total shoulder arthroplasty

Abstract

Shoulder arthroplasty is a demanding procedure with a known complication rate. Most complications are associated with the glenoid component, a fact that has stimulated investigation into that specific component of the implant. Avoiding glenoid component malposition is very important and is a key reason for recent developments in pre-operative planning and instrumentation to minimise risk.Patient-specific instrumentation (PSI) was developed as an alternative to navigation systems, originally for total knee arthroplasty, and is a valid option for shoulder replacements today. It offers increased accuracy in the placement of the glenoid component, which improves the likelihood of an optimal outcome.A description of the method of pre-operative planning and surgical technique is presented, based on the author’s experience and a review of the current literature.Cite this article: Gomes N. Patient-specific instrumentation for total shoulder arthroplasty. EFORT Open Rev 2016;1:177-182. DOI: 10.1302/2058-5241.1.000033.

Accuracy of patient-specific instrumentation in shoulder arthroplasty: a systematic review and meta-analysis

“…This finding suggests that PSI can be particularly advantageous for novice or low-volume shoulder surgeons. Given that TSA still involves a number of surgeon-dependent steps despite the use of PSI, including achieving an adequate reaming depth and screw placement, the relationship between surgeon expertise and accuracy with PSI should be studied more extensively 17 . A second possible explanation is that many of the trials may have been performed on glenoids with less severe glenoid pathology than what would normally be encountered in clinical practice, particularly those performed using cadavers.…”

“…The time necessary for production was not reported consistently, and available production times ranged from 2 to 5 weeks at minimum 16, 40. Surgeons may not be willing to wait over a month for device production, which could potentially influence case timing or overall volume or could limit the applicability of PSI to certain elective cases 17 . For surgeons to properly evaluate the practicality and investment value of PSI technology, objective and readily available information on associated costs and time of production is critical.…”

Surgeon-designed patient-specific instrumentation improves glenoid component screw placement for reverse total shoulder arthroplasty in a population with small glenoid dimensions

“…While initial results have been promising, CN has inherent limitations that may preclude its popularisation. In addition to the initial cost and learning curve, the potential for machine inaccuracy and extra intra-operative steps may contribute to increased surgical duration [12,25,26]. PSI is advantageous in that most important measurement takes place pre-operatively, and the accuracy of the guide is not subject to computer error intra-operatively.…”

“…There is also a wide variation in scapular bone morphology and density over short distances and no means of identifying regions of high quality bone stock intra-operatively [8]. Previously, intra-operative computer navigation has been used to address these issues, but inherent technical drawbacks and lengthened operating time preclude its popularisation [12].…”

“…Patient-specific instrumentation (PSI) using threedimensionally (3D) printed guides is an increasingly popular tool for improving surgical accuracy across various contexts. PSI has been shown to produce more accurate glenoid component placement in rTSA and total shoulder arthroplasty [6,12,13]. However, the efficacy of PSI inachieving better screw purchase in scapular bone has not been evaluated before.…”