Shoulder and Elbow Recent Publications

This multicenter study examined how well two diagnostic tests — synovial fluid analysis and frozen section biopsies — can detect bacterial infection in patients undergoing revision shoulder replacement surgery. Researchers analyzed data from 425 revision surgeries across multiple institutions, evaluating these tests against results from intraoperative tissue cultures, which serve as the gold standard for confirming infection. The most important finding was that the percentage of neutrophils (infection-fighting white blood cells) in the synovial fluid was the strongest predictor of bacterial presence, with an optimal cutoff of roughly 72–77%, performing best in cases that clearly met established infection criteria. Frozen sections showed moderate usefulness for identifying confirmed infections but were much less reliable in ambiguous cases, where sensitivity dropped below 30%. These findings are significant because shoulder joint infections are often caused by slow-growing bacteria like Cutibacterium, making them notoriously difficult to diagnose, and this study provides the first large-scale evidence-based thresholds to guide surgeons in interpreting preoperative and intraoperative diagnostic tests during revision shoulder surgery.

This study examined how well the 2018 International Consensus Meeting (ICM) diagnostic criteria classify shoulder periprosthetic joint infections (PJI), which occur when a shoulder replacement becomes infected. Researchers prospectively collected data from 490 revision shoulder surgeries across multiple centers, categorizing each case as Definite, Probable, Possible, or Unlikely PJI based on standardized clinical, microbiological, and laboratory criteria. They found that 14% of cases met criteria for Definite PJI, while 57% were classified as Unlikely PJI, and notable demographic differences existed between groups, such as Probable PJI patients being younger and more likely to be male. Strikingly, *Cutibacterium acnes* (*C. acnes*) was the most commonly identified bacterium in both Definite (25%) and Non-Definite (27%) PJI cases, challenging the traditional assumption that it is a low-virulence organism that plays a minor role in true infections. These findings support the validity of the ICM diagnostic framework while also suggesting that current classifications of bacterial virulence may need to be reconsidered to improve treatment decision-making for shoulder PJI.

This multicenter study examined whether standard preoperative blood tests — specifically erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) — can reliably predict bacterial infection in patients undergoing revision shoulder joint replacement surgery. Researchers analyzed data from 579 revision shoulder arthroplasties, comparing blood test results to bacteria found in cultures taken during surgery, and categorized patients based on whether they had a definite or non-definite periprosthetic joint infection (PJI). The most common bacteria identified was Cutibacterium, a low-virulence organism typically associated with subtle or hard-to-detect infections. In patients with obvious signs of infection, CRP showed moderate usefulness with an optimal cutoff of around 10 mg/L, while ESR performed poorly overall, with its diagnostic accuracy falling below chance in patients without clear infection symptoms. These findings suggest that standard blood tests have significant limitations in detecting bacterial presence before revision shoulder surgery, particularly in cases without obvious infection, highlighting the need for better diagnostic tools in this clinical setting.

This study examined whether two popular AI chatbots, ChatGPT and Gemini, give patients accurate information about glenohumeral arthritis (a form of shoulder joint disease) by comparing their responses to official guidelines from the American Academy of Orthopaedic Surgeons (AAOS). Researchers asked both AI tools questions based on 12 high-quality clinical recommendations and had two independent reviewers score each response as agreeing, neutral, or disagreeing with the established guidelines. ChatGPT aligned with the guidelines in only 50% of cases, while Gemini performed somewhat better at 75%, though the difference between them was not statistically significant. Both tools also fabricated or incorrectly cited research references, with ChatGPT misrepresenting 4 out of 6 sources and Gemini misrepresenting 5 out of 32. These findings suggest that while AI chatbots may seem helpful, patients and physicians should be cautious about relying on them for medical guidance, as their responses can be incomplete, misleading, or supported by nonexistent evidence.

A survey study examined how often shoulder surgeons actually use advanced preoperative imaging, 3D planning tools, and intraoperative technologies like robotics and navigation in their daily practice, despite these tools being frequently highlighted at conferences and in medical literature. Researchers distributed a 16-question survey to 161 members of the PacWest Shoulder and Elbow Society, receiving responses from 85 surgeons (53%), asking about their use of CT scans, MRI, 3D CT-based surgical planning, and technologies such as patient-specific instruments, navigation systems, mixed reality, and robotics. Results showed that while 71% of surgeons routinely obtained preoperative CT scans, only 60% routinely used 3D planning for primary shoulder replacement and just 47% for revision cases, with advanced intraoperative technologies seeing even lower adoption rates ranging from 6% to 15%. Surgeons who had been in practice more than 10 years were significantly more likely to use 3D planning infrequently, and nearly half of all respondents cited time constraints and imaging protocol difficulties as major barriers. These findings reveal a notable gap between how these technologies are portrayed in academic settings and how widely they are actually used, suggesting that future research should focus on directly linking 3D planning and enabling technologies to improved patient outcomes in order to better justify their broader adoption.

This study examined whether using robotic assistance during reverse total shoulder arthroplasty (rTSA) — a procedure that replaces a damaged shoulder joint — is economically worthwhile based on its ability to prevent early implant failure requiring revision surgery. Researchers built a break-even model using real-world cost estimates, including a $1,500 added cost per robotic procedure, a 2.1% early revision rate, and a $22,920 average cost per revision surgery. The analysis found that robotic assistance would only pay for itself if it prevented one revision for every 15 surgeries performed, which would require reducing the revision rate by 6.55% — more than three times the actual observed revision rate of 2.1%. This means robotic-assisted rTSA cannot realistically break even under typical clinical conditions when judged only by early revision prevention. The authors suggest that economic justification might improve in higher-risk patient populations, at high-volume centers that can spread out equipment costs, or if future research demonstrates long-term benefits such as improved implant survival and patient outcomes.

Chronic instability of the sternoclavicular (SC) joint — where the collarbone meets the breastbone — is a rare but debilitating condition that sometimes requires surgery when non-surgical treatments fail. Researchers conducted a systematic review following PRISMA guidelines, analyzing 12 studies that included 164 patients who underwent 169 SC joint reconstructions, to evaluate surgical techniques, patient outcomes, and complication rates. The most commonly used approach was bicortical reconstruction, which anchors the graft through both layers of bone, and this technique was especially favored for posterior instability. Regardless of the surgical technique used — bicortical versus unicortical, or donor (allograft) versus patient's own tissue (autograft) — all patients showed meaningful improvements in self-reported outcomes, and 83% were able to return to sport or work, though some had activity limitations. These findings suggest that SC joint reconstruction is a safe and effective treatment option across multiple surgical approaches, while also highlighting the need for larger, comparative studies to better guide surgical decision-making.

Anatomic shoulder arthroplasty aims to reconstruct the natural shape of the humeral head to restore proper joint mechanics and soft-tissue balance, but poor component sizing can lead to "overstuffing," which limits range of motion and causes impingement. This review describes how surgeons assess humeral head reconstruction using a "perfect circle" method that aligns the prosthetic surface with key bony landmarks, while also recommending additional measurements such as radius of curvature and glenohumeral thickness for a more complete evaluation. The authors found no consistent evidence that stemless, short-stem, or standard-length implants produce better reconstructions than one another, emphasizing that surgical technique and familiarity with a given implant system are the most critical factors. Precise osteotomy depth and angle are especially important with stemless and short-stem designs, and techniques such as careful osteophyte removal, intramedullary guides, and intraoperative fluoroscopy can improve accuracy. Clinically, small deviations from native anatomy appear to be tolerable, but center-of-rotation offsets greater than 3 to 4 mm from the ideal position have been linked to worse patient outcomes, underscoring the importance of achieving reasonably accurate humeral head reconstruction.

This study examined how surgeons' pre-existing beliefs and cognitive biases influence the way they update their treatment preferences when presented with new clinical evidence. Researchers used a Bayesian simulation — a mathematical model that tracks how probability estimates change with new information — to follow three hypothetical shoulder surgeons with different starting beliefs about whether anatomic or reverse total shoulder replacement is superior for advanced shoulder arthritis. Each simulated surgeon was exposed to ten clinical trials modestly favoring reverse shoulder replacement, under both unbiased and confirmation-biased conditions. Without bias, all three surgeons shifted their beliefs substantially toward the evidence; however, the surgeon who strongly favored anatomic replacement at the outset remained 64% confident in that preference despite consistent contradictory evidence when confirmation bias was applied, compared to dropping to only 25% confidence without bias. These findings highlight that a surgeon's initial beliefs can be just as influential as the actual data in shaping treatment recommendations, and suggest that structured interventions like decision-support tools, peer review, and debiasing strategies may help reduce unwarranted variation in patient care.