Can We Reliably Compare Outcomes of Ream-and-Run and Anatomic Total Shoulder Arthroplasty?: Commentary on an article by James Levins, MD, et al.: "Comparison of Humeral-Head Replacement with Glenoid-Reaming Arthroplasty (Ream and Run) Versus Anatomic Total Shoulder Arthroplasty. A Matched-Cohort Study".

Abstract

Commentary Ream-and-run arthroplasty represents one of many options for the challenging problem of glenohumeral arthritis in the young active patient. Proponents of this procedure may contend that, despite higher revision rates in the short term compared with anatomic total shoulder arthroplasty (aTSA), ream-and-run arthroplasty may obviate potential longer-term complications related to polyethylene loosening and wear, such as glenoid bone loss and osteolysis leading to reverse baseplate fixation failure and humeral osteolysis and loosening1,2. It may also allow patients to avoid activity restrictions related to concern over polyethylene-related complications and to potentially avoid another surgery in their lifetime. However, these theoretical long-term advantages must be balanced against the fact that patients undergoing ream and run are at higher risk for early revision surgery. Data on ream-and-run arthroplasty outside of the originating institution are sparse, so this study by Levins et al. comparing aTSA and ream and run is useful to consider. Comparing these 2 procedures is no easy task; at baseline, patients choosing to undergo ream-and-run arthroplasty are different in many ways (age, sex, psychosocial factors, and glenoid morphology and retroversion) compared with patients choosing to undergo aTSA3. This usually results in a demographics table full of significant differences4, and therefore, non-comparable patient-reported outcomes and revision rates. Levins et al. attempted to address this in 2 ways. First, they included 2 distinct time periods: an earlier period in which no ream-and-run procedures were performed, and a later period in which both ream and run and aTSA were offered. Such an approach may reduce any surgical decision-making bias that leads to different baseline patient characteristics. Second, they utilized propensity-score matching (PSM). Short of a randomized controlled trial comparing ream and run and aTSA, which would be nearly impossible to undertake, this study provides the most comparable cohorts in the literature since the initial matched-cohort study reported by Dr. Matsen 15 years ago5. This PSM approach used is not perfect, and it is important to understand 2 major limitations of the methodology. First, one must consider the prototypical patient undergoing ream and run: a motivated, resilient male patient with glenoid biconcavity and retroversion who wants to participate in heavy lifting and impact sports. Many of these characteristics are addressed in the PSM algorithm, but notably, activity level and psychosocial attributes like resilience and motivation, thought to be very important in selecting a patient for a ream-and-run procedure, were absent. These characteristics are more difficult to objectively assess, but without taking them into account, the study cannot convince the reader that these cohorts truly comprised similar patients. The second major limitation of the PSM in this study pertains to matching on the basis of duration of follow-up. By doing so, the authors reduce the benefit of including a time period in which ream and run was not offered to patients. While the alternative of not matching on follow-up leads to other issues, such as imbalanced follow-up durations and differences in patient management, this study’s approach of matching length of follow-up increases the probability that the total shoulder cohort contains more patients from the latter time period in which more motivated, resilient, and active patients were likely offered ream-and-run arthroplasty. It should also be noted that the senior author, similar to Dr. Matsen, has substantial experience with the ream-and-run procedure. The technical nuances in addressing glenoid deformity and soft-tissue balancing during the procedure are different from those considered during aTSA. As with any other surgical procedure, higher volume produces better results, and this surgeon’s thoughtful approach to the operative technique and rehabilitation after ream and run likely were adapted over time to optimize patient outcomes. The generalizability of these results may not be assured. Despite these limitations, the authors should be commended for providing us with the largest report on the ream-and-run procedure outside of Dr. Matsen’s cohort. They demonstrate that acceptable results, similar to those of aTSA, can be achieved in this challenging population. Further studies objectively assessing activity level and the psychosocial aspects of patient selection will help us further elucidate who the “optimal” ream-and-run candidate is. Continued follow-up of the cohorts in this study will be essential to determining whether the perceived long-term value of avoiding glenoid polyethylene in the young patient with glenohumeral arthritis is worth it.