Glenoid Morphology (Shoulder Replacement )
Glenoid morphology classification and Computed Tomography Scanning prior to Total Shoulder Arthroplasty: A Population-Level Analysis from the Australian Orthopaedic Association National Joint Replacement Registry
Ingoe, Pareyon, Jomaa, Launay, Italia, Maharaj, Gill, Holder, Whitehouse, Cutbush, Gupta
https://i0.wp.com/asesjournal.com/wp-content/uploads/2017/01/Fgure-1-and-2.jpg?w=2184 KeyWords: Shoulder Replacement, Glenoid Morphology, Anatomic Shoulder Replacement, Reverse Shoulder Replacement
Introduction
Evaluation of glenoid and humeral morphology is important prior to total shoulder arthroplasty. Measured on standard radiographs, evaluated further by computed tomography (CT). This study analyzed data from the Australian Orthopaedic Association National Joint Replacement Registry. It assessed the effect of glenoid morphology and preoperative CT scan on short-term implant survivorship in shoulder replacement procedures.
Methods
Primary total aTSA and rTSA for all diagnoses during the period April 2004 to December 2022 were identified. Glenoid morphology was classified according to the Walch classification and to those with or without preoperative CT scan. The cumulative percent revision (CPR) calculated based upon glenoid morphology and CT scan availability. Hazard ratios (HR) from Cox proportional hazards models were performed to compare the revision rates among groups.
Results
There were 4,071 (10.7%) primary stemmed aTSA, 3,196 (8.4%) stemless aTSA and 30,702 (80.9%) primary rTSA. Of these, 2,694 (77%), 2,543 (88.6%) and 21,007 (83.8%) patients had a preoperative CT scan, respectively. There was no difference in the CPR at any timepoint between glenoid type A or B for any arthroplasty type. Glenoid morphology (type A or B) alone. In conjunction with a preoperative CT scan (yes or no) did not affect the revision rate in any combination. Making shoulder replacement outcomes seem similar regardless of the type.
Conclusion
Preoperative glenoid morphology and preoperative CT scanning does not affect the early rate of revision of stemmed or stemless aTSA and rTSA. Future evaluations of CT scanning in this setting should consider other performance indicators ( PROMS).
My Opinion
Big database studiesare to be treated with caution. The data is collected without a specific goal. It is then used retrospectively to ask and “answer” several questions by authors, without access to the raw data.
Specifically in this study: 1) The implant may be loose but the patient ultimately was the one deciding to undergo a revision surgery. If the implant was loose and the patient did not want revision surgery, then a skew / bias influences the conclusions of this study. 2) If only revision surgery is the end goal of this study, it will underestimate the number of loose / failed implants. 3) There is variation between surgeons with respect to classifying a CT image into a morphologic classification grade. When retrospective “big data” reviews dont access the raw images and uniformly classify dysmorphic glenoids, an automatic bias influences the conclusion. 4) revision surgery at the short follow up of 5 years is not meanigful except to capture very limited and specific technical errors or patient circumstances.
Ultimately, pre-operative CT scan ARE valuable to aid the surgeon to visualise the operative anatomy, continue to learn as a surgeon, and, in less experienced surgeons, accelerate post-graduate proficiency /development for shoulder replacement procedures.
