This Week in Orthopedics — May 14, 2026

Welcome to This Week in Orthopedics. This week we're covering 9 notable papers spanning major themes in arthroplasty, new evidence in sports medicine, and fundamental insights into bone and tendon biology. Let's dive in.

Arthroplasty Update: Site of Service, Pain, and Complications A major focus this week is on arthroplasty, covering the logistics of where we perform surgery, how we manage pain, and how we deal with long-term complications. We begin with the ongoing site-of-service shift. A large retrospective study in *Spine* analyzed over 1,000 patients who underwent cervical disc replacement in a freestanding ambulatory surgical center. The analysis included single- and multi-level procedures, up to four levels. The key finding was a favorable peri-discharge safety profile, with zero immediate complications or hospital transfers reported [9]. This large dataset provides strong evidence supporting the migration of even complex spine procedures to the outpatient setting.

This trend is not without its complexities. A commentary in *The Journal of Bone and Joint Surgery* addresses the parallel rise of surgeon equity ownership in these ambulatory surgery centers [2]. While this model can drive efficiency and innovation, the authors argue it necessitates updated safeguards to maintain transparency and public trust. They call for standardized ownership disclosure, risk-adjusted site-of-service reporting, and independent case review to ensure clinical decision-making remains neutral as lower-risk patients increasingly move to ASCs.

Once the patient is in the operating room, pain control is paramount. A prospective randomized trial, also in *The Journal of Bone and Joint Surgery*, compared two popular regional anesthesia techniques for total hip arthroplasty [7]. Investigators randomized 192 patients to either an anterior quadratus lumborum block plus a lateral femoral cutaneous nerve block, or to a standard periarticular and local infiltration analgesia. Critically, both groups received an identical anesthetic cocktail containing ropivacaine and dual glucocorticoids—dexamethasone and methylprednisolone.

Results The primary outcome was opioid consumption, measured in oral morphine milligram equivalents, on postoperative day one. The study found no significant difference between the nerve block group and the periarticular infiltration group. Secondary outcomes, including pain scores and functional recovery out to one year, were also similar. The only notable difference was a slightly lower fasting serum glucose on day one in the nerve block group.

The Clinical Takeaway For total hip arthroplasty, this trial suggests that when using a modern multimodal protocol that includes dual glucocorticoids, a more complex anterior nerve block does not seem to offer any additional benefit over a well-placed periarticular injection in terms of opioid reduction or pain control.

Shifting to complications, a multicenter study in the *Journal of Shoulder and Elbow Surgery* provides new insights into diagnosing periprosthetic joint infection, or PJI, in the shoulder [5]. The study utilized data from a prospective cohort of nearly 500 revision shoulder arthroplasties to evaluate the 2018 International Consensus Meeting, or ICM, diagnostic categories.

Key Finding The most striking result was the microbiology. *Cutibacterium acnes* was the most commonly cultured bacteria, not just in the 'Possible' or 'Probable' infection groups, but in 25% of 'Definite' PJI cases. This finding challenges the traditional classification of *C. acnes* as a low-virulence contaminant and suggests it is a primary pathogen even in clear-cut shoulder infections. This may prompt us to reconsider how we interpret cultures and which organisms we label as 'virulent' in the context of PJI.

Finally, we look at long-term outcomes for a less common but important procedure: total elbow arthroplasty. A systematic review in the *Journal of Shoulder and Elbow Surgery* analyzed 76 studies encompassing over 4,200 total elbow arthroplasties from the last 25 years [6].

The Good News The procedure provides meaningful benefits. At long-term follow-up, patients reported low pain scores, good functional scores on the Mayo Elbow Performance Score, and improved arcs of motion.

The Bad News The complication and revision rates are high and have remained static over the past two and a half decades. The review found a weighted mean survivorship at a minimum of 7 years of only 86.3%. The all-cause reoperation rate was nearly 17%, with deep infection at 3.2% and periprosthetic fractures near 6.8%. This highlights the persistent trade-off with total elbow arthroplasty: good functional improvement at the cost of substantial long-term surgical morbidity.

Stability and Evidence in Sports Medicine In sports medicine, we look at two papers that force us to reconsider both the stability of our evidence and the stability of the elbow joint. First, a systematic review in *The American Journal of Sports Medicine* questions the robustness of our evidence for ACL graft selection [4]. Investigators applied a statistical tool called the Fragility Index to 29 randomized controlled trials comparing hamstring, bone-patellar tendon-bone, quadriceps tendon, and allografts.

The Fragility Index The Fragility Index is the minimum number of patients in a trial whose outcome would need to change to flip a statistically significant result to non-significant. A low index means the conclusion is fragile.

Results The median fragility index across all significant outcomes was just two. This means in the typical trial, changing the outcome for only two patients—for example, from no re-tear to a re-tear—would erase the statistical significance of the finding. Furthermore, in nearly 90% of the studies, the number of patients lost to follow-up was greater than the fragility index, casting further doubt on the reliability of the conclusions. The authors conclude that the current evidence for any single graft's superiority is statistically weak.

While one paper deconstructs old evidence, another provides new biomechanical data for an emerging technology. In the *Journal of Shoulder and Elbow Surgery*, a cadaveric study evaluated the Internal Joint Stabilizer for treating lateral ulnar collateral ligament, or LUCL, injuries of the elbow [8].

The Study Researchers tested eight cadaveric elbows, measuring varus instability with the LUCL intact, with the LUCL disrupted, and with the LUCL disrupted but augmented by the Internal Joint Stabilizer.

Findings The device significantly reduced varus angle deviations after LUCL disruption, bringing stability closer to the intact state. This effect was most pronounced in the mid-range of flexion, from 60 to 90 degrees, where the elbow is most vulnerable to posterolateral rotatory instability. These findings provide biomechanical support for the IJS as a viable augmentation for this challenging injury.

From the Bench to Rare Disease Our final section moves from clinical trials to the underlying biology of orthopedic conditions. First, a study in *Science Translational Medicine* reframes our understanding of the role of nerves in tendinopathy [3]. We typically think of nerves in chronic tendinopathy as simple transmitters of pain signals. This basic science research in mouse models suggests they also play a protective, regulatory function.

The Mechanism Researchers found that sensory nerves grow into the tendon and interact with tenocytes and macrophages. When these nerves were removed or their signaling was blocked, tendinopathic changes worsened. They identified a key signaling molecule, fibroblast growth factor 1, or FGF1, which is secreted by the nerves and appears to prevent tendon degeneration. This protective FGF1 signaling was also observed in human tendinopathy specimens.

The Implication This work points to a potential new therapeutic strategy: instead of just blocking pain, targeting the FGF1 pathway could be a way to actively prevent or reverse the degenerative changes of tendinopathy.

Finally, a major randomized clinical trial in *JAMA* addresses a critical question in the management of adults with osteogenesis imperfecta, or OI [1]. The trial aimed to determine if an anabolic agent, teriparatide, followed by an anti-resorptive, zoledronic acid, could reduce fracture risk.

Methods 350 adults with OI were randomized to either two years of daily teriparatide followed by a single zoledronic acid infusion, or to standard care, which could include bisphosphonates but prohibited anabolic drugs.

Results The primary endpoint was the incidence of new, imaging-proven fractures. After two years, there was no difference. Approximately 37% of patients in the teriparatide group had a new fracture, compared to 36% in the standard care group. While the active treatment did significantly increase bone mineral density at the lumbar spine and total hip, this did not translate into a reduction in fractures.

Conclusion This is a landmark negative trial. It powerfully suggests that in osteogenesis imperfecta, low bone density is not the whole story. The underlying poor bone quality is likely the dominant driver of fractures, and simply increasing BMD with this sequential anabolic and anti-resorptive therapy is not enough to prevent them.

If you only have time for one paper this week, make it the osteogenesis imperfecta trial in *JAMA* [1]. It's a methodologically rigorous, multicenter RCT in a rare disease that provides a clear and definitive answer to an important clinical question. Its negative result fundamentally challenges our reliance on BMD as a surrogate for fracture risk in diseases of poor bone quality.

Here are the key takeaways from this week in Orthopedics. First, in adults with osteogenesis imperfecta, sequential therapy with two years of teriparatide followed by zoledronic acid does not reduce fracture risk, despite improving bone mineral density [1]. Second, for total hip arthroplasty pain control, an anterior quadratus lumborum and lateral femoral cutaneous nerve block was not superior to periarticular infiltration when both regimens included dual glucocorticoids [7]. Third, in shoulder PJI, remember that *C. acnes* is a primary pathogen found frequently even in definite infections, not just a contaminant [5]. Fourth, be skeptical of claims of graft superiority in ACL reconstruction; a new analysis shows the evidence from many randomized trials is statistically fragile [4]. And finally, large-scale data now support the safety and feasibility of performing even multi-level cervical disc replacements in the ambulatory surgery center setting [9].

That's your roundup for This Week in Orthopedics. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.

This is an automated summary generated by artificial intelligence, which can make mistakes. Always review the original source materials.