At a recent Cantina luncheon, conversation among five shoulder surgeons concluded that shoulder surgeons are becoming divided with respect to their approaches to arthritic shoulders with glenoid retroversion: there are the "acceptors" and the "correctors".
The acceptors ream the glenoid only enough to create a smooth concavity that corresponds to the backside of the glenoid component. The correctors strive to reduce glenoid retroversion to 15 degrees or less, using posteriorly augmented glenoid components, anterior "high side" reaming, or posterior bone graft.
The acceptor approach requires only standardized plain radiographs and the occasional use of anteriorly eccentric humeral head components and rotator interval plication if excessive posterior decentering is noted at surgery.
By contrast, the corrector approach usually requires a preoperative CT scan, three dimensional planning, and some means of carrying out the plan in the operating room, such as patient specific instrumentation or computer guidance.
The literature available to date does not demonstrate a superiority of either approach in terms of clinical outcomes in the management of arthritic shoulders with a retroverted glenoid.
It is of interest to see how the corrector and acceptor approaches are used in a membership-based, dues prepaid, direct health care system, where optimization of both outcome as well as total outpatient and inpatient costs are priorities. The authors of Use of Preoperative CT Scans and Patient-Specific Instrumentation May Not Improve Short-Term Adverse Events After Shoulder Arthroplasty showed how the corrector-oriented technologies - preoperative computed tomography (CT) scans and patient-specific instrumentation (PSI) - are used in their integrated health-care system.
They identified 8,117 primary elective anatomic or reverse total shoulder arthroplasties (7,372 patients) performed by 130 surgeons between 2015 to 2020 with an average follow-up of 2.9 years (maximum, 6 years).
During the period of this observational study, the 130 surgeons in this healthcare system chose to use preoperative CT scans in less than half of the primary shoulder arthroplasties and to use PSI in one out of nine cases.
CT Scans
The use of preoperative CT scans is probably associated with the surgeons' desire to correct preoperative glenoid version.
Over the period of this study it appears that the surgeons became more selective in their use of preoperative CT scans:
(1) less than half of all shoulder arthroplasty patients had preoperative CT scans; this percentage trended downward with time
(2) patients with glenoid types B1 and B2 were slightly more likely to get preoperative CT scans, whereas patients with A1 glenoids were slightly less likely to have CT scans; yet for each glenoid type, less than one third of patients had preoperative CT scans
and had a higher likelihood of venous thromboembolism (OR = 1.79; 95% CI = 1.18 to 2.74) compared with those without CT scans.
The use of PSI is probably associated with the surgeons' desire to correct preoperative glenoid version.
Patients with PSI use had a higher likelihood of 90-day deep infection (OR = 7.74; 95% CI = 1.11 to 53.94), which may be related to the increased OR time.
3553 (44%) of the patients received a Tornier implant; of these 400 (11.3%) had their implants inserted using patient specific instrumentation. Shoulders with PSI were more likely to be male and to have a Walch type B or C preoperative glenoid pathoanatomy. Surgical procedures using PSI also had a longer mean operative time.
The patients receiving arthroplasty with PSI had slightly increased rates of early revision.
Comment: At this point it is not clear how much "correction" of version is necessary to obtain a great outcome for the patient.
In Does Postoperative Glenoid Retroversion Affect the 2-Year Clinical and Radiographic Outcomes for Total Shoulder Arthroplasty? the authors presented a series of anatomic total shoulders in which neither 3D imaging or PSI was used; postoperative glenoid retroversion was not associated with inferior clinical results at 2 years after surgery.
Glenoid retroversion does not impact clinical outcomes or implant survivorship after total shoulder arthroplasty with minimal, noncorrective reaming found reliable increases in patient satisfaction and clinical outcomes in patients with up to 40 degrees of retroversion.
Baseplate retroversion does not affect postoperative outcomes after reverse shoulder arthroplasty. found no significant difference in postoperative functional outcomes, range of motion, or complications between patients who had baseplate retroversion ≤15° vs. those who had retroversion >15°.
Many of the published articles discussing CT planning, PSI and computer guidance focus on the accuracy and precision achieved with the techniques rather than clinical outcomes; see
Accuracy of 3-Dimensional Planning, Implant Templating, and Patient-Specific Instrumentation in Anatomic Total Shoulder Arthroplasty.
Version and inclination obtained with 3-dimensional planning intotal shoulder arthroplasty: do different programs produce the same results?
Accuracy of patient-specific instrumentation in shoulder arthroplasty: a systematic review and meta-analysis.
Commercial 3-dimensional imaging programs are not created equal: version and inclination measurement positions vary among preoperative planning software.
Strategies to assist in the correction of glenoid pathoanatomy have not been associated with clinically significantly improved patient outcomes.
For example, the authors of The influence of computed tomography preoperative planning on clinical outcomes after anatomic total shoulder arthroplasty: a matched cohort analysis. did not find a clinically significant difference between the outcomes of total shoulders performed without and with 3D CT planning.
In Patient-specific Instrumentation Versus Standard Surgical Instruments in Primary Reverse Total Shoulder Arthroplasty: A Retrospective Comparative Clinical Study, patient having RTSA with PSI did not achieve significantly different clinical outcomes than those without PSI.
The authors of Early clinical outcomes following navigation-assisted baseplate fixation in reverse total shoulder arthroplasty: a matched cohort study found that navigated and non-navigated RSAs yielded similar rates of improvement in range of motion and functional outcome scores.
In conclusion, more research is needed to determine the clinical outcomes for the corrector and acceptor approaches to shoulders with different degrees of glenoid retroversion.
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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link).
Follow on twitter: https://twitter.com/shoulderarth
Follow on facebook: click on this link
Follow on facebook: https://www.facebook.com/frederick.matsen
Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/
Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link).
Shoulder rehabilitation exercises (see this link).
