Shoulder and Elbow Recent Publications

This study investigated which improvements in shoulder function best predict patient satisfaction two years after three types of shoulder replacement surgery: anatomic total shoulder arthroplasty (aTSA), reverse total shoulder arthroplasty (rTSA), and ream-and-run (RnR) arthroplasty. Researchers analyzed data from 1,048 patients at a single academic medical center, using the Simple Shoulder Test (SST) to measure functional outcomes and a satisfaction questionnaire to assess whether patients felt their surgery was successful. Overall satisfaction rates were highest for aTSA and RnR patients (around 80–84%) compared to rTSA patients (69%), and across all three procedure types, the ability to sleep comfortably and to rest the arm without pain were the functional improvements most strongly linked to patient satisfaction. While these two comfort-related outcomes were consistently important regardless of surgery type, the relationship between satisfaction and other shoulder functions—such as lifting or overhead reach—varied depending on which procedure was performed. These findings can help surgeons set more realistic expectations for patients before shoulder replacement by highlighting that pain relief and comfort at rest are the outcomes most likely to drive a patient's sense of surgical success.

This large multicenter study examined which patient characteristics and surgical implant positioning factors increase the risk of stress fractures of the acromion and scapular spine following reverse shoulder arthroplasty (RSA), a common procedure used to treat severe shoulder conditions. Researchers analyzed data from 6,320 patients across 15 U.S. institutions, using imaging measurements and statistical modeling to identify predictors of these fractures. The overall stress fracture rate was 3.8%, and the strongest risk factors for both fracture types were poor bone quality (osteoporosis), inflammatory arthritis, and rotator cuff muscle damage, with women and older patients also at higher risk. Regarding surgical technique, excessive lateralization on the socket (glenoid) side of the implant was associated with higher fracture risk, while increasing the offset on the arm (humeral) side appeared to be protective. These findings suggest that surgeons should carefully screen high-risk patients before RSA and consider implant positioning strategies that favor humeral-sided lateralization to help reduce the likelihood of post-operative stress fractures.

This pilot study examined whether adding blood flow restriction (BFR) training to standard rehabilitation after ACL reconstruction (ACLR) could better preserve or improve quadriceps muscle strength and function compared to a sham (non-therapeutic) version of BFR training. Ten patients recovering from ACLR were randomly assigned to receive either real BFR or sham BFR training as part of their post-surgery rehabilitation, with muscle strength, MRI-based muscle volume, and patient-reported outcomes assessed at 8 and 36 weeks after surgery. While both groups showed significant strength improvements by 36 weeks, there were no meaningful differences between the BFR and sham groups in quadriceps or hamstring strength, muscle volume, muscle fat composition, or knee function scores at either time point. Importantly, early BFR use was found to be safe, with no complications or increased adverse events reported. Although these findings suggest that BFR may not offer additional benefits beyond standard rehabilitation for ACLR patients, the small sample size limits firm conclusions, and the authors emphasize that larger, well-controlled studies are needed to more definitively evaluate BFR's role in ACL recovery.

This study investigated whether the amount of *Cutibacterium* bacteria present on a patient's skin at the time of shoulder joint replacement surgery affects surgical outcomes or the risk of developing a prosthetic joint infection (PJI). Researchers collected bacterial cultures from both the unprepared skin surface and the freshly cut wound edge in 256 patients undergoing different types of primary shoulder arthroplasty, with an average follow-up period of nearly four years. Bacterial growth was measured semi-quantitatively, and statistical models were used to assess relationships between bacterial load and patient-reported shoulder function as well as reoperation rates. The results showed only weak associations between *Cutibacterium* skin load and a few functional outcome measures, and bacterial load was not significantly linked to reoperation rates; only one patient developed a PJI during the follow-up period. These findings suggest that while *Cutibacterium* is the most common bacterium associated with shoulder PJIs, its presence on the skin at the time of surgery does not strongly predict short- to medium-term outcomes, and longer follow-up studies are needed to clarify its true clinical significance.

Shoulder periprosthetic joint infection (PJI) is a serious complication following joint replacement surgery, and accurately diagnosing it requires consistent, standardized criteria. This systematic review analyzed 231 published studies on revision shoulder arthroplasty to determine which diagnostic criteria researchers were using to identify shoulder PJI, and whether practices changed after the 2019 International Consensus Meeting (ICM) released shoulder-specific infection guidelines. The researchers found that while most studies (81%) reported some form of diagnostic criteria, the methods used varied widely, with only 11.3% of pre-2019 studies referencing established guidelines compared to 52.3% of studies published in 2019 or later. The adoption of the ICM's shoulder-specific criteria has grown, with nearly 29% of more recent studies incorporating them, suggesting the guidelines are gaining traction in the field. However, the overall inconsistency in how shoulder PJI is diagnosed across studies remains a significant problem, as it undermines the reliability of clinical research and makes it harder to compare results or develop best practices for patient care.

This study examined how bones change around the humeral (upper arm) component of shoulder replacement implants over time, and whether those changes affect patient outcomes. Researchers analyzed X-rays and clinical data from 170 patients who underwent either total shoulder arthroplasty or hemiarthroplasty, with a minimum follow-up of four years and an average of seven years. They found that bone thinning or resorption most commonly occurred around the medial calcar, greater tuberosity, and lateral shaft of the humerus, and that greater bone loss was associated with a higher degree of implant filling within the bone canal. Importantly, patients with total shoulder replacements who also showed significant radiolucencies (dark lines indicating bone loss) around the glenoid component had more extensive humeral bone changes and worse functional outcomes, suggesting that osteolysis from implant debris may contribute beyond simple stress shielding. These findings highlight that bone changes around humeral implants should be interpreted carefully, particularly in the context of glenoid component loosening, as they may signal a more complex biological process with real clinical consequences.

Researchers developed an artificial intelligence (AI) model to automatically identify key bone landmarks on shoulder X-rays taken before and after anatomic shoulder replacement surgery. They trained the deep learning model using 240 annotated X-rays that were expanded to 2,260 images through data modification, then tested it against measurements made by experienced surgeons on 60 separate X-rays. The AI model identified landmarks with an average deviation of only 1.9 mm compared to surgeon measurements, and performed similarly well across 14 different measurements of bone and implant positioning, with a mean deviation of about 2.9 mm. Scapular (shoulder blade) landmarks were identified slightly more accurately than humeral (upper arm bone) landmarks. These findings suggest that AI-driven landmark detection can serve as a reliable, efficient, and bias-free alternative to manual X-ray analysis, which has important implications for improving how surgeons evaluate and monitor shoulder replacement outcomes over time.

Shoulder replacement surgery is often evaluated using standardized scoring systems that measure how much pain decreases and function improves, but it is unclear whether these standard thresholds truly reflect what patients consider a successful outcome. This study examined 406 patients who underwent anatomic total shoulder arthroplasty and were followed for two years, using the Simple Shoulder Test (SST) alongside a patient satisfaction survey to compare commonly used success thresholds against thresholds mathematically optimized to match patient satisfaction. The researchers found that traditional measures like the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) performed poorly at predicting whether patients actually felt satisfied with their results, while thresholds based on percentage of maximum possible improvement and final SST score aligned much more closely with patient-reported satisfaction. Additionally, the factors that predicted a "successful" outcome varied considerably depending on which threshold was used, highlighting how the choice of measurement tool can influence clinical conclusions. These findings suggest that the field may need to reconsider how surgical success is defined after shoulder replacement, particularly as healthcare increasingly prioritizes outcomes that matter most to patients themselves.

This study examined whether the angle (version) at which the baseplate component is positioned during reverse shoulder arthroplasty (RSA) affects patients' ability to perform everyday activities. Researchers reviewed outcomes from 115 patients who had RSA surgery and were followed for at least two years, dividing them into four groups based on how far their baseplate angled forward (anteversion) or backward (retroversion) from neutral. Overall shoulder function scores and the ability to perform tasks requiring internal rotation, external rotation, and cross-body movement were similar across all four groups, with no significant differences in complication or revision rates. The one notable exception was that patients with moderate to severe anteversion reported more difficulty putting on a coat compared to those in other version groups. These findings suggest that surgeons may not always need to pursue complex corrective techniques to achieve neutral baseplate positioning in RSA, as moderate deviations in version did not meaningfully worsen patient-reported outcomes or functional rotation.