"Trend" Statement Use in the Orthopaedic Literature.

INTRODUCTION: For research to effectively guide clinical decision making, appropriate interpretation of data is paramount. The P-value is a useful tool for guiding the interpretation of data. However, despite its utility, the P-value is not without limitations. Of particular concern is the use of "trend statements" to describe non-statistically significant findings, a practice which introduces subjectivity and variability into data interpretation and can lead to the drawing of undue conclusions. METHODS: An audit of original research articles published from January 2022 to December 2022 in four high-impact orthopaedic journals was conducted. The selected journals were queried to identify instances in which a non-statistically significant result was labeled as a "trend." The use of trend statements and associated information was recorded and analyzed. RESULTS: One thousand two hundred sixty articles were included in the analysis. 81 articles (6.4%) included a trend statement to describe a non-statistically significant result. Only two articles (2.5%) formally defined what constituted a trend. In 28.8% of cases, the associated P-value was > 0.10. DISCUSSION: Trend statements are used to describe non-statistically significant findings with moderate frequency in the orthopaedic literature. Given the potentially misleading effects of trend statements, efforts should be made to mitigate their use. If trend statements are to be used, attention should be paid to defining what constitutes a "trend", explicitly acknowledging the lack of statistical significance of the finding to which the trend statement refers, and avoiding drawing undue conclusions from non-statistically significant data.

The subacromial bursa modulates tendon healing after rotator cuff injury in rats.

Rotator cuff injuries result in more than 500,000 surgeries annually in the United States, many of which fail. These surgeries typically involve repair of the injured tendon and removal of the subacromial bursa, a synovial-like tissue that sits between the rotator cuff and the acromion. The subacromial bursa has been implicated in rotator cuff pathogenesis and healing. Using proteomic profiling of bursa samples from nine patients with rotator cuff injury, we show that the bursa responds to injury in the underlying tendon. In a rat model of supraspinatus tenotomy, we evaluated the bursa's effect on the injured supraspinatus tendon, the uninjured infraspinatus tendon, and the underlying humeral head. The bursa protected the intact infraspinatus tendon adjacent to the injured supraspinatus tendon by maintaining its mechanical properties and protected the underlying humeral head by maintaining bone morphometry. The bursa promoted an inflammatory response in injured rat tendon, initiating expression of genes associated with wound healing, including Cox2 and Il6. These results were confirmed in rat bursa organ cultures. To evaluate the potential of the bursa as a therapeutic target, polymer microspheres loaded with dexamethasone were delivered to the intact bursae of rats after tenotomy. Dexamethasone released from the bursa reduced Il1b expression in injured rat supraspinatus tendon, suggesting that the bursa could be used for drug delivery to reduce inflammation in the healing tendon. Our findings indicate that the subacromial bursa contributes to healing in underlying tissues of the shoulder joint, suggesting that its removal during rotator cuff surgery should be reconsidered.

Hedgehog Activation for Enhanced Rotator Cuff Tendon-to-Bone Healing.

BACKGROUND: Rotator cuff repair is a common orthopaedic procedure, yet the rate of failure to heal after surgery is high. Repair site rupture is due to poor tendon-to-bone healing and lack of regeneration of the native fibrocartilaginous enthesis. During development, the enthesis is formed and mineralized by a pool of progenitors activated by hedgehog signaling. Furthermore, hedgehog signaling drives regenerative enthesis healing in young animals, in contrast to older animals, in which enthesis injuries heal via fibrovascular scar and without participation of hedgehog signaling. HYPOTHESIS: Hedgehog activation improves tendon-to-bone healing in an animal model of rotator cuff repair. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 78 adult Sprague-Dawley rats were used. Supraspinatus tendon injury and repair were completed bilaterally, with microsphere-encapsulated hedgehog agonist administered to right shoulders and control microspheres administered to left shoulders. Animals were sacrificed after 3, 14, 28, or 56 days. Gene expression and histological, biomechanical, and bone morphometric analyses were conducted. RESULTS: At 3 days, hedgehog signaling pathway genes Gli1 (1.70; P = .029) and Smo (2.06; P = .0173), as well as Runx2 (1.69; P = .0386), a transcription factor of osteogenesis, were upregulated in treated relative to control repairs. At 14 days, transcription factors of tenogenesis, Scx (4.00; P = .041), and chondrogenesis, Sox9 (2.95; P = .010), and mineralized fibrocartilage genes Col2 (3.18; P = .031) and Colx (1.85; P = .006), were upregulated in treated relative to control repairs. Treatment promoted fibrocartilage formation at the healing interface by 28 days, with improvements in tendon-bone maturity, organization, and continuity. Treatment led to improved biomechanical properties. The material property strength (2.43 vs 1.89 N/m2; P = .046) and the structural property work to failure (29.01 vs 18.09 mJ; P = .030) were increased in treated relative to control repairs at 28 days and 56 days, respectively. Treatment had a marginal effect on bone morphometry underlying the repair. Trabecular thickness (0.08 vs 0.07 mm; P = .035) was increased at 28 days. CONCLUSION: Hedgehog agonist treatment activated hedgehog signaling at the tendon-to-bone repair site and prompted increased mineralized fibrocartilage production. This extracellular matrix production and mineralization resulted in improved biomechanical properties, demonstrating the therapeutic potential of hedgehog agonism for improving tendon-to-bone healing after rotator cuff repair. CLINICAL RELEVANCE: This study demonstrates the therapeutic potential of hedgehog agonist treatment for improving tendon-to-bone healing after rotator cuff injury and repair.

The subacromial bursa is a key regulator of the rotator cuff and a new therapeutic target for improving repair.

Rotator cuff injuries result in over 500,000 surgeries performed annually, an alarmingly high number of which fail. These procedures typically involve repair of the injured tendon and removal of the subacromial bursa. However, recent identification of a resident population of mesenchymal stem cells and inflammatory responsiveness of the bursa to tendinopathy indicate an unexplored biological role of the bursa in the context of rotator cuff disease. Therefore, we aimed to understand the clinical relevance of bursa-tendon crosstalk, characterize the biologic role of the bursa within the shoulder, and test the therapeutic potential for targeting the bursa. Proteomic profiling of patient bursa and tendon samples demonstrated that the bursa is activated by tendon injury. Using a rat to model rotator cuff injury and repair, tenotomy-activated bursa protected the intact tendon adjacent to the injured tendon and maintained the morphology of the underlying bone. The bursa also promoted an early inflammatory response in the injured tendon, initiating key players in wound healing. In vivo results were supported by targeted organ culture studies of the bursa. To examine the potential to therapeutically target the bursa, dexamethasone was delivered to the bursa, prompting a shift in cellular signaling towards resolution of inflammation in the healing tendon. In conclusion, contrary to current clinical practice, the bursa should be retained to the greatest extent possible and provides a new therapeutically target for improving tendon healing outcomes. One Sentence Summary: The subacromial bursa is activated by rotator cuff injury and regulates the paracrine environment of the shoulder to maintain the properties of the underlying tendon and bone.

Minimum 2-Year Analysis of S2-Alar-Iliac Screw Fixation for Adult Spinal Deformity.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: Determine the rate and risk factors for S2AI screw-related pain after adult spinal deformity surgery with a minimum 2-year follow-up. METHODS: A consecutive 83 spinal deformity patients undergoing surgical treatment between August 2015 and December 2017 with minimum 2-year follow-up for S2AI screw complication and screw-related pain were included. Linear regression was performed on various risk factors and postoperative S2AI screw-related pain. Subset analysis of 53 patients was performed on preoperative and postoperative SRS and ODI scores, operative data, and radiographic data. RESULTS: The overall proportion of S2AI screw-related pain was 9.6%. An S2AI screw complication was identified radiographically in 10.8% of patients; among these, 22.2% experienced S2AI screw-related pain. 3.4% of all patients underwent S2A1 screw removal. The SRS, ODI, sagittal vertical axis (SVA), and coronal alignment scores/measurements improved following treatment in all patients. However, the mean difference for the pre and postoperative SRS function score (1.2 ± 0.5 vs 0.9 ± 0.8) and SVA (4.0 ± 4.9 cm vs 2.1 ± 4.8 cm) were higher for the pain group. CONCLUSIONS: A minimum 2-year analysis of S2AI screw fixation in adult spinal deformity patients showed that 9.6% of patients experienced S2AI screw-related pain and 3.4% of patients had S2A1 screws removed. The size and the number of S2AI screws did not predict postoperative pain, nor were radiographic findings correlated with clinical outcomes. The patient outcome scores, coronal alignment, and SVA improved for all patients, but within the pain group there was an overall larger change in the SVA and SRS function score.

Femoral head to lower lumbar neural foramen distance as a novel radiographic parameter to predict postoperative stretch neuropraxia.

OBJECTIVE: Lumbosacral fractional curves in adult spinal deformity (ASD) patients often have sharp coronal curves resulting in significant pain and imbalance. Postoperative stretch neuropraxia after fractional curve correction can lead to discomfort and unsatisfactory outcomes. The goal of this study was to use radiographic measures to increase understanding of the relationship between postoperative stretch neuropraxia and fractional curve correction. METHODS: In 62 ASD patients treated from 2015 to 2018, radiographic review was performed, including measurement of the distance between the lower lumbar neural foramen (L4 and L5) in the concavity and convexity of the lumbosacral fractional curve and the ipsilateral femoral heads (FHs; L4-FH and L5-FH) in pre- and postoperative anteroposterior spine radiographs. The largest absolute preoperative to postoperative change in distance between the lower lumbar neural foramen and the ipsilateral FH (ΔL4/L5-FH) was used for analysis. Chi-square analyses, independent and paired t-tests, and logistic regression were performed to study the relationship between L4/L5-FH and stretch neuropraxia for categorical and continuous variables, respectively. RESULTS: Of the 62 patients, 13 (21.0%) had postoperative stretch neuropraxia. Patients without postoperative stretch neuropraxia had an average ΔL4-FH distance of 16.2 mm compared to patients with stretch neuropraxia, who had an average ΔL4-FH distance of 31.5 mm (p < 0.01). Patients without postoperative neuropraxia had an average ΔL5-FH distance of 11.1 mm compared to those with stretch neuropraxia, who had an average ΔL5-FH distance of 23.0 mm (p < 0.01). Chi-square analysis showed that patients had a 4.78-fold risk of developing stretch neuropraxia with ΔL4-FH > 20 mm (95% CI 1.3-17.3) and a 5.17-fold risk of developing stretch neuropraxia with ΔL5-FH > 15 mm (95% CI 1.4-18.7). Logistic regression analysis indicated that the odds of developing stretch neuropraxia were 15:1 with a ΔL4-FH > 20 mm (95% CI 3-78) and 21:1 with a ΔL5-FH > 15 mm (95% CI 4-113). CONCLUSIONS: The novel ΔL4/L5-FH distances are strongly associated with postoperative stretch neuropraxia in ASD patients. A ΔL4-FH > 20 mm and ΔL5-FH > 15 mm significantly increase the odds for patients to develop postoperative stretch neuropraxia.

The Telehealth Spine Physical Examination: A Practical Approach Learned During the COVID-19 Pandemic.

BACKGROUND: The COVID-19 pandemic has led to a surge in the use of telehealth visits across the country to minimize in-person visits and to limit the spread of COVID-19. To date, no standards or outlines for telehealth spine examinations have been detailed and many surgeons simply defer the physical examination when performing telehealth visits. Nevertheless, just as physical examination of the spine is an integral part of live clinical encounters, appropriately modified physical examinations should also be part of virtual visits. METHODS: In this study we provide our methodology for guiding providers and patients in efficiently performing telehealth spine examinations. RESULTS: The study details steps for efficiently performing a physical examination in the telehealth setting. Our written suggestions are supplemented with photographs and video recordings to help streamline the virtual examination. CONCLUSIONS: An effective and efficient spine physical examination can be performed during telehealth visits. Future directions include verifying the findings from our virtual physical examination with in-person examinations.

Risk of Gastrointestinal Bleeding With Extended Use of Nonsteroidal Anti-Inflammatory Drug Analgesia After Joint Arthroplasty.

BACKGROUND: Chronic nonsteroidal anti-inflammatory drug (NSAID) use is associated with gastrointestinal bleeding via inhibition of endogenous mucosal protection and platelet aggregation. This study aimed to determine whether extended NSAIDs after joint arthroplasty is associated with increased risk of gastrointestinal bleeding. METHODS: This was a retrospective study examining 28,794 adults who underwent joint arthroplasty by one of 50 surgeons from 2016 to 2018. Episodes of gastrointestinal bleeding within 90 days postoperatively were identified prospectively. Postoperative medications were reported directly by patients with electronic questionnaires. The primary analysis was performed using binary logistic regression. RESULTS: A total of 74 (0.26%) episodes of gastrointestinal bleeding occurred within 90 days (median 8 days) postoperatively. Of 5086 patients with complete data included in the primary analysis, 59.6% had used NSAIDs with median duration of 2 weeks (interquartile range, 0-6 weeks). Patients with gastrointestinal bleeding were significantly older (71.3 vs 67.0 years), required longer hospitalizations (2.1 vs 1.5 days), and more commonly had a history of peptic ulcers (10.8% vs 0.9%). However, there was no positive association between NSAID use and gastrointestinal bleeding. In fact, the odds of gastrointestinal bleeding were lower in patients taking NSAIDs. Gastrointestinal bleeding was associated with anticoagulants, antiplatelet agents, and, to a lesser extent, aspirin. CONCLUSION: NSAIDs were not associated with gastrointestinal bleeding and may be prescribed safely for a majority of patients after joint arthroplasty. The greatest odds of gastrointestinal bleeding occurred in patients with peptic ulcer disease and those who received antiplatelet and anticoagulation agents. Increasing age and bilateral surgery were also associated with gastrointestinal bleeding. LEVEL OF EVIDENCE: Level III.

Biomechanical Evaluation of a Dynamic Stabilization System for the Prevention of Proximal Junctional Failure in Adult Deformity Surgery.

STUDY DESIGN: Biomechanical spine model. Comparison of stress in the implant and the adjacent cranial segment was done with conventional rigid versus dynamic stabilization system (DS) fixation. OBJECTIVE: The aim of this study was to study stress at the proximal end of spinal fixation with a novel DS. SUMMARY OF BACKGROUND DATA: High stress at the implant bone junction may cause proximal junctional failure (PJF) in adult deformity surgery. METHODS: Five life-size spine models were instrumented with pedicle screws and a 5.5-mm Titanium rod from T8-S1. The same models were subsequently instrumented with a similar rod and DS between T8-9 pedicle screws. The spine model was loaded with 25 Nm static load cranial to the proximal fixation in six directions. Strains were measured from the proximal screws. Disc pressure was measured from the proximal instrumented segment (T8-9) and cranial adjacent segment (T7-8). RESULTS: Rigid fixation produced highest strain at T8, followed by T10 then T9. In contrast, DS fixation produced highest strain at T10, followed by T9 then T8. Strain at T8 was significantly less with DS fixation than rigid fixation (P = 0.019). The T10 screw strain was not significantly higher with DS stabilization compared to rigid fixation (P = 0.091). Rigid fixation allowed no load-sharing or pressure rise at T8-9 but an abrupt rise at T7-8. DS system permitted load-sharing and pressure rise in T8-9; the difference compared to rigid fixation was significant in flexion loading (P = 0.04) and similar trend but not significant in extension (P = 0.09). DS system produced a rise in the adjacent segment disc pressure (T7-8), which was smaller than rigid fixation but not significant. CONCLUSION: Long spinal fixation using rigid rods produces maximum stress at the proximal end screw and increases adjacent disc pressure, possibly leading to PJF. Dynamic stabilization at the cranial end segment may prevent PJF by reducing these factors.Level of Evidence: N/A.

General vs Spinal Anesthesia for Total Joint Arthroplasty: A Single-Institution Observational Review.

BACKGROUND: Total joint arthroplasty (TJA) can be successfully carried out under general (GA) or spinal anesthesia (SA). The existing literature does not adequately illustrate which technique is optimal. The purpose of this study is to prospectively compare the effects of anesthesia technique on TJA outcomes. METHODS: This 2-year, prospective, observational study was conducted at a single institution where patients receiving primary TJA were consecutively enrolled. Patients were contacted postoperatively to assess for any 90-day complications. The primary outcome of the study was the overall complication rate. RESULTS: A total of 2242 patients underwent total hip arthroplasty (n = 656; 29.26%) or total knee arthroplasty (n = 1586; 70.74%) between 2015 and 2017. Of these procedures, 1325 (59.10%) were carried out under SA and 917 (40.90%) were carried out under GA. Patients in the GA cohort had higher mean Charlson Comorbidity Index scores (0.05 SA vs 0.09 GA; P < .05) and higher average body mass index (29.35 SA vs 30.24 GA; P < .05). On multivariate analysis, patients in the SA cohort had a significantly lower overall complication rate relative to their GA counterparts (7.02% vs 10.14%; odds ratio, 0.66; 95% confidence interval, 0.49-0.90; P < .05). In addition, length of stay in the GA cohort was significantly longer (2.43 [SD, 1.62] vs 2.18 [SD, 0.88] days; P < .01) and a larger percentage of GA patients were discharged to a nursing facility (32.28% vs 25.06%; odds ratio, 0.55; 95% confidence interval, 0.44-0.70; P < .05). CONCLUSION: Our study demonstrates that SA for TJA is associated with a decrease in overall complications and healthcare resource utilization.

Intra-articular Corticosteroid Injection Following Total Knee Arthroplasty: Is It Effective?

BACKGROUND: Total knee arthroplasty (TKA) for the majority of patients with severe knee osteoarthritis provides relief of symptoms and improved function. However, there remains a subset of dissatisfied patients despite an unremarkable workup. A corticosteroid injection (CSI) is a commonly used nonsurgical treatment for painful knee osteoarthritis but its efficacy in a replaced knee remains unknown. METHODS: A retrospective chart review identified primary TKA patients who subsequently received a CSI into a replaced knee from 2015 to 2016 by a single surgeon. Patients receiving a CSI underwent clinical examination, laboratory analysis to rule out infection, and radiographic evaluation before CSI. Patient variables were recorded and a patient satisfaction survey assessed the efficacy of the injection. The survey response rate was 70.1%. RESULTS: Of the 129 responders, 82.9% remembered the injection. The average time from index arthroplasty to injection was median 5.3 months (interquartile range, 2.1-23.4) and 30.8% of patients received more than 1 injection (range, 1-5). Overall, 76.6% reported decreased pain, 57.9% reported increased motion, and 65.4% reported long-term decreased swelling. Improvement lasted greater than 1 month for 56.1% of patients, and overall 84.1% reported improvement (slight to great) in the knee following CSI. No patient developed a periprosthetic joint infection (PJI) within 1 year of injection. CONCLUSION: This study suggests that certain patients following TKA may benefit from a CSI. However, this should only be performed once clinical, radiographic, and laboratory examination has ruled out conditions unlikely to improve long term from a CSI.

The Role of Perioperative Surveillance in 90-Day Total Joint Arthroplasty Care.

BACKGROUND: With the recent implementation of a bundled payment model for total joint arthroplasty, healthcare providers are financially responsible for management of complications throughout the 90-day perioperative period. Our aim was to assess the effectiveness of a surveillance system that was implemented to enhance communication during this period. METHODS: A retrospective study was conducted using a prospectively collected database of patients who underwent primary total joint arthroplasty from January 2015 to April 2016. Surveillance was performed using electronic messages and telephone calls. The use of this system in response to several clinical scenarios was measured by the total number of messages and calls exchanged. RESULTS: Communication was greater among patients who experienced a complication (median 8), went to the emergency department (ED; median 9), and were readmitted to the hospital (median 8), relative to patients who had an uncomplicated course (median 5). Additionally, communication was greater among patients who presented to outside facilities for ED visits (median 11) and readmissions (median 9) relative to those who returned to the index hospital for ED visits (median 7) and readmissions (median 6). More distant patients had decreased follow-up attendance but did not have a compensatory increase in use of the surveillance system. CONCLUSION: Patients used the surveillance system to relay information about clinically significant events when such events arose. Additionally, patients who returned to outside facilities used the surveillance system to remain engaged with their original provider. However, more distant patients did not appear to use the surveillance system to compensate for decreased follow-up attendance.

The "Bundle Busters": Incidence and Costs of Postacute Complications Following Total Joint Arthroplasty.

BACKGROUND: Recently, a bundled payment model was implemented in the United States to improve quality and reduce costs. While hospitals may be rewarded for lowering costs, they may be financially exposed by high cost complications, the so-called bundle busters. We aimed at determining the incidence, etiology, and costs of postacute complications after total joint arthroplasty (TJA). METHODS: A retrospective study was conducted using a prospectively collected database of patients who underwent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) from January 2015 to April 2016. Nurse navigators performed postoperative surveillance to identify patients with complications and unplanned clinical events in the 90-day postoperative period. This was combined with episode-of-care costs provided by third-party payers to derive the mean and per capita costs of postacute complications and clinical events. RESULTS: Among 3018 THA and 5389 TKA patients, 3.35% of THA and 2.62% of TKA patients sought emergency department or urgent care services, 2.62% of THA and 3.69% of TKA patients required hospital readmission, and 3.99% of TKA patients required manipulation. Joint-related complications were more common following THA, whereas medical complications were more frequent after TKA. The most costly complications after THA were periprosthetic fracture, dislocation, and myocardial infarction, compared to deep infection, myocardial infarction, and pulmonary embolism after TKA. CONCLUSION: Joint-related complications were among the most costly events after TJA, and given their higher incidence after THA, had a larger impact on per capita costs. Medical complications were more common after TKA and more costly. Despite these events, postacute complications made up less than 5% of the total 90-day costs of TJA.