NSAID therapy effects on healing of bone, tendon, and the enthesis

Effect of Gabapentin on Tendon-to-Bone Healing in a Rat Model of Rotator Cuff Repair

BACKGROUND

Gabapentin is often used as an analgesic after rotator cuff repair surgery and is recommended as an additional analgesic for arthroscopic rotator cuff repairs. However, evidence of its effects on biological healing mechanisms is lacking. The objective of this study was to investigate the potential of gabapentin in improving tendon-to-bone healing after rotator cuff repair using a rat model.

MATERIALS AND METHODS

A total of 20 male rats were randomly allocated to one of two groups: group 1 (repair only, n=10) or group 2 (gabapentin injection, n=10). The rats in the experimental group (group 2) were administered 80 mg/kg of gabapentin subcutaneously 30 minutes before surgery, followed by 80 mg/kg subcutaneously every 24 hours for 48 hours. We used the left shoulder of every rat, while for biomechanical analysis, we used the right shoulder.

RESULTS

There was no significant difference in the load to failure, ultimate stress, or elongation between the groups. Collagen continuity, orientation, and density were better in group 2 than group 1.

CONCLUSION

In a rat model of rotator cuff repair, gabapentin had a positive impact on the quality of collagen organization at the junction between the tendon and bone, while preserving the biomechanical properties. We propose the use of gabapentin as a supplementary analgesic agent for postoperative pain relief after arthroscopic rotator cuff repair; however, further studies of the effect of gabapentin on biological healing mechanisms are required. [Orthopedics. 2024;47(5):e241-e246.].

Sacral insufficiency fracture: a single-center experience of 185 patients with a minimum 5-year follow-up

PURPOSE

Sacral insufficiency fracture (SIF) is a commonly underdiagnosed etiology of back pain, especially in the geriatric and osteoporotic population. In this clinical study, we present our experience of 185 patients who were diagnosed with SIF and managed either with conservative or surgical treatment with a minimum 5-year follow-up.

MATERIALS AND METHOD

Patients who were diagnosed with SIF, managed either conservatively or surgically, and had a minimum 5-year follow-up medical record were included in this study. CT scans and MR imaging including coronal STIR sequence were obtained from all. Bone densitometry (DEXA) was performed to detect accompanying osteopenia or osteoporosis. Patients were treated either conservatively or surgically. VAS and ODI scores were evaluated prior to the treatment and 1st day, 10th day, 3rd month, and 1st year postoperatively.

RESULTS

The mean age of 185 patients was 69.2 and the mean follow-up period was 7.23 years (range: 5-11 years). 46 (24.9%) patients had a previous spinal or spinopelvic surgery and spinal instrumentation was implemented in 22(11.89%) of them. The time interval between the fusion surgery and the diagnosis of SIF was approximately 9.48 weeks. The fracture line could be detected with the MRI in 164 patients and with the CT in 177 patients. The fracture was bilateral in 120 (64.8%) patients. 102 patients were treated conservatively, and 83 received sacroplasty. VAS and ODI scores showed better improvement in pain and functionality in the surgical management group than in the conservative management group.

CONCLUSION

SIF should be considered in the differential diagnosis of back and pelvic pain, especially in elderly and osteoporotic patients. MRI with coronal STIR imaging should be a standard protocol for patients with a risk of SIF. Our results show that sacroplasty provides better and faster pain relief and recovery than conservative management.

Mind the Gap: Unraveling the Intricate Dance Between Alzheimer's Disease and Related Dementias and Bone Health

PURPOSE OF REVIEW

This review examines the linked pathophysiology of Alzheimer's disease/related dementia (AD/ADRD) and bone disorders like osteoporosis. The emphasis is on "inflammaging"-a low-level inflammation common to both, and its implications in an aging population.

RECENT FINDINGS

Aging intensifies both ADRD and bone deterioration. Notably, ADRD patients have a heightened fracture risk, impacting morbidity and mortality, though it is uncertain if fractures worsen ADRD. Therapeutically, agents targeting inflammation pathways, especially Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and TNF-α, appear beneficial for both conditions. Additionally, treatments like Sirtuin 1 (SIRT-1), known for anti-inflammatory and neuroprotective properties, are gaining attention. The interconnectedness of AD/ADRD and bone health necessitates a unified treatment approach. By addressing shared mechanisms, we can potentially transform therapeutic strategies, enriching our understanding and refining care in our aging society. This review article is part of a series of multiple manuscripts designed to determine the utility of using artificial intelligence for writing scientific reviews.

Post-Operative Complications Associated with Long-Term NSAID or Long-Term Opioid Use Prior to Lumbar Spinal Fusion Surgery

OBJECTIVE

Lower back pain (LBP) has been implicated as a significant cause of chronic pain in the United States, often requiring analgesic use. In this study, we investigate the trends in long-term preoperative NSAID (LTN) and Opioid (LTO) use in patients with low back pain in the United States, and the resultant postoperative complications following lumbar fusion.

METHODS

In this retrospective cohort study of patients with lumbar pathologies, multivariate population-based regression models were developed using the 2010-2017 National Readmission Database. Short-term complications (30-, 90-day) and long-term complications (180-, 300-day) were analyzed at readmission.

RESULTS

Of patients diagnosed with LBP (N = 1427,190) we found a rise in LTO users and a fall in LTN users following 2015. We identified 654,264 individuals who received a lumbar spine fusion, of which 22,975 were LTN users and 11,213 were LTO users. LTO users had significantly higher total inpatient charges (p-value<0.0001) and LOS (p-value<0.0001), while LTN users had lower rates of acute infection (OR: 0.993, 95% CI: 0.987-0.999, p = 0.017) and acute posthemorrhagic anemia (OR: 0.957, 95% CI: 0.935-0.979, p < 0.001) at primary admission. Readmission analysis showed that LTN use had significantly lower odds of readmission compared to LTO use at all time points (p < 0.01 for all). LTN use had significantly higher odds of hardware failure (OR: 1.134, 95% CI: 1.039-1.237, p = 0.005) within 300-days of receiving a lumbar fusion.

CONCLUSIONS

LTO users had significantly higher readmission rates compared to LTN. In addition, we found that LTN use was associated with significantly higher odds of hardware failure at long-term follow-up in patients receiving lumbar fusion surgery.

Retrospective evaluation and review of approaches for nonspecific lameness in dogs presented to an emergency service (2013-2014): 134 cases

OBJECTIVE

This retrospective study aimed to characterize and evaluate the emergency approach, diagnosis, management, treatment, and follow-up of nonspecific canine lameness cases.

DESIGN

Retrospective case series from September 25, 2013 to September 25, 2014.

SETTING

The study was conducted at an urban university teaching hospital.

ANIMALS

A consecutive sample of dogs presenting to the emergency service with nonspecific lameness in the designated timeframe was used to identify 134 cases. Owners were contacted to participate in the follow-up survey; dogs that died prior to data collection were excluded from the survey. Medical records were reviewed for lameness localization, etiology of lameness, diagnostics obtained, medications prescribed, and owner recommendations.

INTERVENTIONS

Based on review of the medical records, the lameness localization, presumptive source of lameness (joint, soft tissue, neurological, or bone), diagnostics obtained, medications prescribed, and owner recommendations were recorded. Survey data included duration of lameness, perceived response to treatment, and activity level.

MEASUREMENTS AND MAIN RESULTS

Definitive diagnoses were not assigned in 88.8% of lameness cases. A presumptive diagnosis of soft tissue injury was assigned in 45.3% of cases. Single limb lameness was more prevalent than multiple limb lameness. Owners whose dogs were treated with medication were significantly more likely to report that the lameness resolved (P = 0.049). Dogs with injury localized to ≥1 of the joints were significantly less likely to have resolution of lameness (P = 0.037). Treatment recommendations were predominantly pain control and activity restriction.

CONCLUSIONS

Nonspecific lameness represents approximately 4% of canine urban emergency cases. Highlighting the points of clinical care considerations in understanding the etiology of lameness in dogs represents an opportunity for improved patient care and growth in emergency referral and follow-up.

Silk protein sericin: a promising therapy for Achilles tendinopathy-evidence from an experimental rat model

OBJECTIVE

This study investigated the efficacy of sericin in treating experimental Achilles tendinopathy (AT) in rats via the transforming growth factor-beta (TGF-β)/mothers against decapentaplegic (Smad) pathway compared with diclofenac sodium (DS).

METHOD

An AT model was induced in rats using collagenase enzyme type I and divided into 5 groups: C (control), AT (diseased control), ATS (AT treated with sericin), ATN (AT treated with DS), and ATSN (AT treated with sericin and DS). Sericin injection was given on the 3rd and 6th days by intratendinous injection (0.8 g/kg/mL), and DS was administered for 14 days by oral gavage (1.1 mg/kg/day). Serum concentrations of total oxidant-antioxidant status (TOS-TAS), TGF-β1, decorin, Smad2, and connective tissue growth factor (CTGF) were measured. Histopathologic and immunohistochemical (IHC) studies were conducted on Achilles tendon samples.

RESULTS

The TOS, oxidative stress index (OSI), TGF-β1, Smad2, CTGF, and decorin serum concentrations were significantly higher in AT than in C and significantly lower in ATS than in AT (P<0.05). Histopathological examination revealed that irregular fibers, degeneration, and round cell nuclei were significantly elevated in AT. Spindle-shaped fibers were similar to those in C, and degeneration was reduced in ATS. TGF-β1 and Smad2/3 expression was increased, and collagen type I alpha-1 (Col1A1) expression was decreased in AT vs. C (P=0.001). In the ATS, TGF-β1 and Smad2/3 expression decreased, and Col1A1 expression increased. The Bonar score significantly increased in the AT group (P =0.001) and significantly decreased in the ATS group (P =0.027).

CONCLUSION

Sericin shows potential efficacy in reducing oxidative stress and modulating the TGF-β/Smad pathway in experimental AT models in rats. It may be a promising therapeutic agent for AT, warranting further clinical studies for validation. Key Points • This study revealed that sericin mitigates AT-induced damage through the TGF-β/Smad pathway in an AT rat model. • ELISA and IHC investigations corroborated the effectiveness of sericin via the pivotal TGF-β/Smad pathway in tissue repair. • Evidence indicates that sericin enhances collagen synthesis,shapes tendon fiber structure, and diminishes histopathological degeneration. • Sericin's antioxidant properties were reaffirmed in its AT treatment application.

Unbiased gene expression analysis of the delayed fracture healing observed in Zucker diabetic fatty rats

Aims

Impaired fracture repair in patients with type 2 diabetes mellitus (T2DM) is not fully understood. In this study, we aimed to characterize the local changes in gene expression (GE) associated with diabetic fracture. We used an unbiased approach to compare GE in the fracture callus of Zucker diabetic fatty (ZDF) rats relative to wild-type (WT) littermates at three weeks following femoral osteotomy.

Methods

Zucker rats, WT and homozygous for leptin receptor mutation (ZDF), were fed a moderately high-fat diet to induce T2DM only in the ZDF animals. At ten weeks of age, open femoral fractures were simulated using a unilateral osteotomy stabilized with an external fixator. At three weeks post-surgery, the fractured femur from each animal was retrieved for analysis. Callus formation and the extent of healing were assessed by radiograph and histology. Bone tissue was processed for total RNA extraction and messenger RNA (mRNA) sequencing (mRNA-Seq).

Results

Radiographs and histology demonstrated impaired fracture healing in ZDF rats with incomplete bony bridge formation and an influx of intramedullary inflammatory tissue. In comparison, near-complete bridging between cortices was observed in Sham WT animals. Of 13,160 genes, mRNA-Seq analysis identified 13 that were differentially expressed in ZDF rat callus, using a false discovery rate (FDR) threshold of 10%. Seven genes were upregulated with high confidence (FDR = 0.05) in ZDF fracture callus, most with known roles in inflammation.

Conclusion

These findings suggest that elevated or prolonged inflammation contributes to delayed fracture healing in T2DM. The identified genes may be used as biomarkers to monitor and treat delayed fracture healing in diabetic patients.

Evolution of Perioperative Pain Management in Shoulder Arthroplasty

Historically, opioids have been used as a primary conservative treatment for pain related to glenohumeral osteoarthritis (GHOA). However, this practice is concerning as it often leads to overuse, which has contributed to the current epidemic of addiction and overdoses in the United States. Studies have shown that preoperative opioid use is associated with higher complication rates and worse outcomes following surgery, particularly for shoulder arthroplasty. To address these concerns, perioperative pain management for shoulder arthroplasty has evolved over the years to the use of multimodal analgesia.

Risk Factors for Revision or Rerupture After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis

BACKGROUND

The rerupture or need for revision after anterior cruciate ligament reconstruction (ACLR) is a serious complication. Preventive strategies that target the early identification of risk factors are important to reduce the incidence of additional surgery.

PURPOSE

To perform a systematic review and meta-analysis to investigate risk factors for revision or rerupture after ACLR.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

Literature searches were performed in PubMed, Embase, and Web of Science from database inception to November 2021 and updated in January 2022. Quantitative, original studies reporting potential adjusted risk factors were included. Odds ratios (ORs) were calculated for potential risk factors.

RESULTS

A total of 71 studies across 13 countries with a total sample size of 629,120 met the inclusion criteria. Fifteen factors were associated with an increase in the risk of revision or rerupture after ACLR: male sex (OR, 1.27; 95% CI, 1.14-1.41), younger age (OR, 1.07; 95% CI, 1.05-1.08), lower body mass index (BMI) (OR, 1.03; 95% CI, 1.00-1.06), family history (OR, 2.47; 95% CI, 1.50-4.08), White race (OR, 1.32; 95% CI, 1.08-1.60), higher posterolateral tibial slope (OR, 1.15; 95% CI, 1.05-1.26), preoperative high-grade anterior knee laxity (OR, 2.30; 95% CI, 1.46-3.64), higher baseline Marx activity level (OR, 1.07; 95% CI, 1.02-1.13), return to a high activity level/sport (OR, 2.03; 95% CI, 1.15-3.57), an ACLR within less than a year after injury (OR, 2.05; 95% CI, 1.81-2.32), a concomitant medial collateral ligament (MCL) injury (OR, 1.62; 95% CI, 1.31-2.00), an anteromedial portal or transportal technique (OR, 1.36; 95% CI, 1.22-1.51), hamstring tendon (HT) autografts (vs bone-patellar tendon-bone [BPTB] autografts) (OR, 1.60; 95% CI, 1.40-1.82), allografts (OR, 2.63; 95% CI, 1.65-4.19), and smaller graft diameter (OR, 1.21; 95% CI, 1.05-1.38). The other factors failed to show an association with an increased risk of revision or rerupture after ACLR.

CONCLUSION

Male sex, younger age, lower BMI, family history, White race, higher posterolateral tibial slope, preoperative high-grade anterior knee laxity, higher baseline Marx activity level, return to a high activity level/sport, an ACLR within less than a year from injury, a concomitant MCL injury, an anteromedial portal or transportal technique, HT autografts (vs BPTB autografts), allografts, and smaller graft diameter may increase the risk of revision or rerupture after ACLR. Raising awareness and implementing effective preventions/interventions for risk factors are priorities for clinical practitioners to reduce the incidence of revision or rerupture after ACLR.

Non-selective NSAIDs do not increase retear rates post-arthroscopic rotator cuff repair: A meta-analysis

BACKGROUND

Arthroscopic rotator cuff repairs (RCRs) are known to be associated with substantial pain and post-operative pain management is critical in overall patients' outcomes. Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used oral medications and can reduce opioid usage. However, controversies arise due to its postulated effect on postoperative tendon healing. As the evidence of safety and efficacy of NSAIDs remains unclear, this study aims to investigate the effect of NSAIDs on retear rates and clinical outcomes.

METHODS

A systematic search of four databases (PubMed, EMBASE, Scopus, and Cochrane Library) was conducted, identifying studies that compared cohorts with post-RCR NSAIDs use versus control groups without NSAID use. Meta-analysis was conducted for retear rate as well as pain and functional outcomes (Visual Analogue Scale and American Shoulder and Elbow Surgeons Shoulder score). Subgroup analysis was conducted for retear rates to determine the overall treatment effect of including selective COX-2 inhibitors.

RESULTS

Six studies were included in the meta-analysis. The total baseline cohort size was 916, with 443 (48.3%) patients in the NSAID group and 473 (51.6%) patients in the control group. There were no statistically significant differences in the baseline characteristics between the two groups. Meta-analysis between the two groups showed that there were no statistically significant differences in retear rates (p ​= ​0.70), early and late post-operative Visual Analogue Scale score (p ​= ​0.10 and p ​= ​0.10, respectively) and latest American Shoulder and Elbow Surgeons Shoulder score (p ​= ​0.31). However, subgroup analysis of retear rates revealed a statistically significant difference between the subgroup including COX-2 selective inhibitor versus non-selective COX inhibitor (p ​< ​0.01).

CONCLUSION

NSAID use in post-arthroscopic RCR pain relief does not increase retear rates and can provide similar clinical outcomes compared to a non-NSAID regimen.

LEVEL OF EVIDENCE

Meta-analysis, level of evidence, 4.

Resorption of Lumbar Disk Herniation: Mechanisms, Clinical Predictors, and Future Directions

INTRODUCTION

Resorption after lumbar disk herniation is a common yet unpredictable finding. It is hypothesized that nearly 70% of lumbar herniated nucleus pulposus (HNP) undergo the resorption to a significant degree after acute herniation, which has led to nonoperative management before surgical planning.

METHODS

This narrative review on the literature from 4 databases (MEDLINE, Cumulative Index to Nursing and Allied Health Literature, Scopus, and Cochrane) examines historical and recent advancements related to disk resorption. Studies were appraised for their description of the predictive factor (e.g., imaging or morphologic factors), pathophysiology, and treatment recommendations.

OBSERVATIONS

We reviewed 68 articles considering the possibility of resorption of lumbar HNP. Recent literature has proposed various mechanisms (inflammation and neovascularization, dehydration, and mechanical traction) of lumbar disk resorption; however, consensus has yet to be established. Current factors that increase the likelihood of resorption include the initial size of the herniation, sequestration, percentage of rim enhancement on initial gadolinium-based magnetic resonance imaging (MRI), composition of inflammatory mediators, and involvement of the posterior longitudinal ligament.

CONCLUSION

Heterogeneity in imaging and morphologic factors has led to uncertainty in the identification of which lumbar herniations will resorb. Current factors that increase the likelihood of disk resorption include the initial size of the herniation, sequestration, percentage of rim enhancement on initial MRI, composition of cellular and inflammatory mediators present, and involvement of the posterior longitudinal ligament. This review article highlights the role of disk resorption after herniation without surgical intervention and questions the role of traditional noninflammatory medications after acute herniation. Further research is warranted to refine the ideal patient profile for disk resorption to ultimately avoid unnecessary treatment, thus individualizing patient care.

The influence of a nanoparticle gel loaded with siRNA-cyclooxygenase on flexor tendon healing: an in vivo animal study

We investigated the influence of cyclooxygenase (COX)-1 and COX-2 siRNAs delivered through a nanoparticle-gel system on the strength of flexor tendon repairs. Sixteen flexor digitorum profundus (FDP) tendons of chicken toes were transected, repaired and wrapped with gels to evaluate gel adherence. We found that the gel adhered to the tendon surface firmly. Next, 56 tendons were used in a first set of in vivo experiments to compare the therapeutic effects of different doses of COX siRNAs. Another 15 tendons were added in a second set to further assess the effects of a dosage of 12 μg. After 4 weeks, the mean strength of the repaired tendons increased most notably in the toes treated with 12 μg COX siRNAs, and the number of samples with low strength (<35 N) was significantly smaller than in the group without molecular treatment. We conclude that COX-1 and COX-2 siRNAs delivered through a nanoparticle-gel system increased the healing strength of the repaired tendons.

Platelet lysate and tendon healing: comparative analysis of autologous frozen-thawed PRP and ketorolac tromethamine in the treatment of patients with rotator cuff tendinopathy

Platelet-rich blood derivatives are being nowadays increasingly used in the treatment of tendon-related pathologies as a rich source of growth factors. We sought to ascertain if local application of platelet lysate (PL) to augment rotator cuff repair ameliorates patient outcomes compared to ketorolac tromethamine treated group. A total of forty patients, with clinical diagnosis of Rotator Cuff Tendinopathy were randomized to receive sub acromial injections of PL every week for a total of 3 injections and two injection of ketorolac tromethamine once every two weeks. Subjective assessments included VAS, SPADI and shoulder range of motion were assessed at baseline and at 1 and 6 months after injection. Taking both control and PL groups, it was vividly seen that the outcomes were identical at the initial state, as well as the short-term one; whereas, when considering the 6-month period, there is a seemingly remarkable superiority in PL group in all parameters.

Mechanoresponsive regulation of fibroblast-to-myofibroblast transition in three-dimensional tissue analogues: mechanical strain amplitude dependency of fibrosis

The spatiotemporal interaction and constant iterative feedback between fibroblasts, extracellular matrix, and environmental cues are central for investigating the fibroblast-induced musculoskeletal tissue regeneration and fibroblast-to-myofibroblast transition (FMT). In this study, we created a fibroblast-laden 3D tissue analogue to study (1) how mechanical loading exerted on three-dimensional (3D) tissues affected the residing fibroblast phenotype and (2) to identify the ideal mechanical strain amplitude for promoting tissue regeneration without initiating myofibroblast differentiation. We applied uniaxial tensile strain (0, 4, 8, and 12%) to the cell-laden 3D tissue analogues to understand the interrelation between the degree of applied mechanical loading amplitudes and FMT. Our data demonstrated that 4% mechanical strain created an anabolic effect toward tissue regeneration, but higher strain amplitudes over-stimulated the cells and initiated fibrotic tissue formation. Under increased mechanical strain amplitudes, fibroblasts were activated from a homeostatic state to a proto-myofibroblast state which resulted in increased cellularity accompanied by increased expressions of extracellular matrix (ECM) components, activation stressors (TGF-β1 and TGF-βR1), and profibrotic markers. This further transformed fibroblasts into α-smooth muscle actin expressing myofibroblasts. Understanding the interplay between the applied degree of mechanical loading exerted on 3D tissues and residing fibroblast phenotypic response is important to identify specific mechanomodulatory approaches for tissue regeneration and the informed mechanotherapy-guided tissue healing strategies.

Fibrocartilaginous Tissue: Why Does It Fail to Heal?

Tendons and ligaments are critical components in the function of the musculoskeletal system, as they provide stability and guide motion for the biomechanical transmission of forces into bone. Several common injuries in the foot and ankle require the repair of ruptured or attenuated tendon or ligament to its osseous insertion. Understanding the structure and function of injured ligaments and tendons is complicated by the variability and unpredictable nature of their healing. The healing process at the tendon/ligament to bone interface is challenging and often frustrating to foot and ankle surgeons, as they have a high failure rate necessitating the need for revision.

Potential Adverse Effect of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) on Bisphosphonate Efficacy: An Exploratory Post Hoc Analysis From a Randomized Controlled Trial of Clodronate

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been reported to have weak but beneficial effects on bone health, including fracture risk, but many epidemiological studies are likely confounded. We explored the relationship between NSAIDs and fracture risk in a post hoc analysis of a well-documented, randomized, placebo-controlled study of the bisphosphonate, clodronate, in which treatment reduced osteoporotic fracture risk by 23%. Concurrent medication use at baseline was used to identify those prescribed oral NSAIDs. Only verified, incident fractures were included in the analysis. A total of 1082 (20.8%) women reported use of NSAIDs at baseline. They were slightly, but significantly, younger (mean 79 versus 80 years, p = 0.004), heavier (mean 66.7 versus 64.7 kg, p < 0.001) than nonusers, with slightly higher femoral neck bone mineral density (FN-BMD, 0.66 versus 0.64 g/cm2 , p < 0.001). In an adjusted model, NSAID use was associated with a significant increase in osteoporotic fracture risk over the 3-year study period (hazard ratio [HR] 1.27; 95% confidence interval [CI], 1.01-1.62; p = 0.039). However, this increase in risk was not statistically significant in the placebo group (HR 1.11; 95% CI, 0.81-1.52). In women receiving clodronate, the effect of the bisphosphonate to reduce osteoporotic fracture risk was not observed in those receiving NSAIDs (HR 0.95; 95% CI, 0.65-1.41; p = 0.81) in contrast to those not using NSAIDs (HR 0.71; 95% CI, 0.58-0.89; p = 0.002). In a subset with hip BMD repeated at 3 years, BMD loss during clodronate therapy was greater in those women receiving NSAIDs than in nonusers (eg, total hip -2.75% versus -1.27%, p = 0.078; femoral neck -3.06% versus -1.12%, p = 0.028), and was not significantly different from that observed in women receiving placebo. The efficacy of the bisphosphonate, clodronate, to reduce fracture risk was largely negated in those receiving NSAIDs. Although the mechanism is unclear, this clinically significant observation requires exploration in studies of commonly used bisphosphonates. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Defining the Profile: Characterizing Cytokines in Tendon Injury to Improve Clinical Therapy

Cytokine manipulation has been widely used to bolster innate healing mechanisms in an array of modern therapeutics. While other anatomical locations have a more definitive analysis of cytokine data, the tendon presents unique challenges to detection that make a complete portrayal of cytokine involvement during injury unattainable thus far. Without this knowledge, the advancement of tendon healing modalities is limited. In this review, we discuss what is known of the cytokine profile within the injured tendinous environment and the unique obstacles facing cytokine detection in the tendon while proposing possible solutions to these challenges. IL-1β, TNF-α, and IL-6 in particular have been identified as key cytokines for initiating tendon healing, but their function and temporal expression are still not well understood. Methods used for cytokine evaluation in the tendon including cell culture, tissue biopsy, and microdialysis have their strengths and limitations, but new methods and approaches are needed to further this research. We conclude that future study design for cytokine detection in the injured tendon should meet set criteria to achieve definitive characterization of cytokine expression to guide future therapeutics.

Acute Quadriceps Tendon Rupture: Presentation, Diagnosis, and Management

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The incidence of quadriceps tendon rupture is estimated to be 1.37 cases per 100,000 people/year, with a predilection for these injuries in patients who are ≥40 years of age.

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Quadriceps tendon ruptures are more likely to occur in the presence of preexisting comorbidities such as rheumatoid arthritis, systemic lupus erythematosus, gout, chronic kidney disease, secondary hyperparathyroidism, diabetes mellitus, and peripheral vascular disease. The most common mechanism of injury is a simple fall.

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Magnetic resonance imaging is the gold-standard test for diagnosing quadriceps tendon ruptures, with a reported sensitivity, specificity, and positive predictive value of 1.0.

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Complete tears require prompt surgical intervention; the most common technique is transosseous sutures passed through longitudinal patellar drill holes. Suture anchors have been proposed as an alternative method; they have shown superior biomechanical results in cadaveric models.

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Early functional mobilization with full weight-bearing and progressive range-of-motion exercises is recommended for rehabilitation following injury.

Lateral epicondylosis: A literature review to link pathology and tendon function to tissue-level treatment and ergonomic interventions

BACKGROUND

Common treatments for lateral epicondylosis (LE) focus on tissue healing. Ergonomic advice is suggested broadly, but recommendations based on biomechanical motion parameters associated with functional activities are rarely made. This review analyzes the role of body functions and activities in LE and integrates the findings to suggest motion parameters applicable to education and interventions relevant to activities and life roles for patients.

PURPOSE

This study examines LE pathology, tendon and muscle biomechanics, and population exposure outlining potentially hazardous activities and integrates those to provide motion parameters for ergonomic interventions to treat or prevent LE. A disease model is discussed to align treatment approaches to the stage of LE tendinopathy.

STUDY DESIGN

Integrative review METHODS: We conducted in-depth searches using PubMed, Medline, and government websites. All levels of evidence were included, and the framework for behavioral research from the National Institutes of Health was used to synthesize ergonomic research.

RESULTS

The review broadened the diagnosis of LE from a tendon ailment to one affecting the enthesis of the capitellum. It reinforced the continuum of severity to encompass degeneration as well as regeneration. Systematic reviews confirmed the availability of evidence for tissue-based treatments, but evidence of well-defined harm reducing occupational interventions was scattered amongst evidence levels. Integration of biomechanical studies and population information gave insight into types of potentially hazardous activities and provided a theoretical basis for limiting hazardous exposures to wrist extensor tendons by reducing force, compression, and shearing during functional activities.

CONCLUSIONS

These findings may broaden the first treatment approach from a passive, watchful waiting into an active exploration and reduction of at-risk activities and motions. Including the findings into education modules may provide patients with the knowledge to lastingly reduce potentially hazardous motions during their daily activities, and researchers to define parameters of ergonomic interventions.

The role of MicroRNAs in tendon injury, repair, and related tissue engineering

Tendon injuries are one of the most common musculoskeletal disorders that cause considerable morbidity and significantly compromise the patients' quality of life. The innate limited regenerative capacity of tendon poses a substantial treating challenge for clinicians. MicroRNAs (miRNAs) are a family of small non-coding RNAs that play a vital role in orchestrating many biological processes through post-transcriptional regulation. Increasing evidence reveals that miRNA-based therapeutics may serve as an innovative strategy for the treatment of tendon pathologies. In this review, we briefly present miRNA biogenesis, the role of miRNAs in tendon cell biology and their involvement in tendon injuries, followed by a summary of current miRNA-based approaches in tendon tissue engineering with a special focus on attenuating post-injury fibrosis. Next, we discuss the advantages of miRNA-functionalized scaffolds in achieving sustained and localized miRNA administration to minimize off-target effects, and thus hoping to inspire the development of effective miRNA delivery platforms specifically for tendon tissue engineering. We envision that advancement in miRNA-based therapeutics will herald a new era of tendon tissue engineering and pave a way for clinical translation for the treatments of tendon disorders.

Ultrasound-guided percutaneous needle tenotomy using Tenex system for refractory lateral epicondylitis; short and long-term effectiveness and contributing factors

BACKGROUND

Ultrasound-guided percutaneous needle tenotomy (USPNT) has been proposed as an alternative treatment to surgical intervention for lateral epicondylitis (LE). The Tenex system (Tenex Health Inc., Lake Forest, CA, USA) for USPNT is an ultrasonic device involving a needle which oscillates at high frequency to debride and aspirate diseased tendon under ultrasound image guidance. This investigation evaluates the efficacy of USPNT using the Tenex system for LE refractory to conservative management. We also seek to evaluate patient-specific factors which may correlate with treatment response.

MATERIALS AND METHODS

PRTEE (Patient-Rated Tennis Elbow Evaluation) and DASH (Disabilities of the Arm, Shoulder, and Hand) questionnaires were completed before performing the Tenex USPNT for all consecutive patients over a course of 38 months (Feb 2015-Mar 2018). Patients were contacted for follow-up evaluations. Paired t test was used to evaluate significant changes in treatment response (p < 0.05). The univariate Tobit regression model was applied followed by multivariate Tobit model with forward selection algorithm. All models were adjusted by preoperative score and follow-up duration.

RESULTS

A total of 37 patients (average age 51± 9 years, M/F:15/22) with refractory LE were included (mean follow-up, 531 days; range, 65-1148 days). Tenex USPNT significantly improved PRTEE and DASH scores (p < 0.001). In some patients, this decrease persisted for up to 3 years after intervention. A significant association between treatment response and post-procedure physical therapy (PT) was present. Post-procedure PT contributes to 60, 68, 59, and 50% of reduction in PRTEE pain, function, total scores, and DASH score, respectively (p < 0.001). No tendon ruptures, post-procedural infections, or other complications were noted.

CONCLUSION

USPNT with Tenex significantly improves symptoms and function in individuals with LE even with long-term follow-up for 3 years. Post-procedure PT is associated with improved treatment response and should be considered after USPNT.

Local shifts in inflammatory and resolving lipid mediators in response to tendon overuse

Tendon inflammation has been implicated in both adaptive connective tissue remodeling and overuse-induced tendinopathy. Lipid mediators control both the initiation and resolution of inflammation, but their roles within tendon are largely unknown. Here, we profiled local shifts in intratendinous lipid mediators via liquid chromatography-tandem mass spectrometry in response to synergist ablation-induced plantaris tendon overuse. Sixty-four individual lipid mediators were detected in homogenates of plantaris tendons from ambulatory control rats. This included many bioactive metabolites of the cyclooxygenase (COX), lipoxygenase (LOX), and epoxygenase (CYP) pathways. Synergist ablation induced a robust inflammatory response at day 3 post-surgery characterized by epitenon infiltration of polymorphonuclear leukocytes and monocytes/macrophages (MΦ), heightened expression of inflammation-related genes, and increased intratendinous concentrations of the pro-inflammatory eicosanoids thromboxane B₂ and prostaglandin E₂ . By day 7, MΦ became the predominant myeloid cell type in tendon and there were further delayed increases in other COX metabolites including prostaglandins D₂ , F_2α , and I₂ . Specialized pro-resolving mediators including protectin D1, resolvin D2 and D6, as well as related pathway markers of D-resolvins (17-hydroxy-docosahexaenoic acid), E-resolvins (18-hydroxy-eicosapentaenoic acid), and lipoxins (15-hydroxy-eicosatetraenoic acid) were also increased locally in response to tendon overuse, as were anti-inflammatory fatty acid epoxides of the CYP pathway (eg, epoxy-eicosatrienoic acids). Nevertheless, intratendinous prostaglandins remained markedly increased even following 28 days of tendon overuse together with a lingering MΦ presence. These data reveal a delayed and prolonged local inflammatory response to tendon overuse characterized by an overwhelming predominance of pro-inflammatory eicosanoids and a relative lack of specialized pro-resolving lipid mediators.

Reparative and Maladaptive Inflammation in Tendon Healing

Tendon injuries are common and debilitating, with non-regenerative healing often resulting in chronic disease. While there has been considerable progress in identifying the cellular and molecular regulators of tendon healing, the role of inflammation in tendon healing is less well understood. While inflammation underlies chronic tendinopathy, it also aids debris clearance and signals tissue repair. Here, we highlight recent findings in this area, focusing on the cells and cytokines involved in reparative inflammation. We also discuss findings from other model systems when research in tendon is minimal, and explore recent studies in the treatment of human tendinopathy to glean further insights into the immunobiology of tendon healing.

Non-steroidal anti-inflammatory drugs and bone healing in animal models-a systematic review and meta-analysis

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAID) have excellent anti-inflammatory and analgesic properties and are extensively used to treat post-traumatic or surgical musculoskeletal pain. Although an extensive literature exists on the administration of NSAID on animal bone healing, no systematic review and meta-analysis of animal studies that investigate the effect of NSAID administration on bone fracture healing. Objective of this study is to conduct a systematic review and meta-analysis to estimate the effect of NSAIDs administration on bone healing biomechanical and histomorphometric measurements in different animal models after bone fracture surgery.

METHODS

We performed a systematic review and meta-analysis of animal studies to estimate the effect of NSAID administration after bone fracture on healing outcomes. We searched eight databases without limiting the search to starting date up to 1 February 2021 for articles on fractured bone healing in animal models in which NSAID were administered.

RESULTS

Out of 6732 articles screened, 47 were included and 3 common bone healing outcomes were analysed: biomechanical properties (maximum force to break, stiffness, and work-to-failure), micro-computed tomography (μ-CT), and histomorphometric measurements. The studies were generally of low-quality scores because crucial information, especially concerning randomization, blinding, and allocation concealment, was poorly reported. Our results show that the negative effects of NSAID after bone fracture on certain biomechanical properties of the healing bones was not statistically significant in mice compared with other animals, in females compared with males, and in younger compared with older animals.

CONCLUSION

The findings demonstrated that NSAIDs administration decreased the biomechanical properties of healing bones after fracture surgery in comparison to the control group. Moreover, different effect on certain outcomes was detected among different sites, sex of the animals, and the time of assessment.

TRIAL REGISTRATION

Protocol published and registered in SYstematic Review Center for Laboratory animal Experimentation (SYRCLE) in 2017, https://www.radboudumc.nl/getmedia/757ec408-7a9e-4635-8233-ae951effea54/Non-Steroidal-Anti-inflammatory-Drugs-and-bone-healing-in-animal-Models-Systematic-Review-and-Meta-Analysis.aspx.

An Innovative Pain Control Method Using Peripheral Nerve Block and Patient-Controlled Analgesia With Ketorolac After Bone Surgery in the Ankle Area: A Prospective Study

Although postoperative pain is inevitable after bone surgery, there is no general consensus regarding its ideal management. We hypothesized that the combination of ultrasound-guided peripheral nerve block (PNB) and patient-controlled analgesia (PCA) with ketorolac would be useful for pain control and reducing opioid usage. This prospective study aimed to evaluate the effectiveness of this method. This study included 95 patients aged >18 years who underwent bone surgery in the ankle area from June to December 2018. All operations were performed under anesthetic PNB, and additional PNB was given for pain control ∼11 hours after preoperative PNB. An additional PCA with ketorolac, started before rebound pain was experienced, was used for pain control in group A (49 patients) but not group B (46 patients). We used intramuscular injection with pethidine or ketorolac as rescue analgesics if pain persisted. A visual analogue scale (VAS) for pain was used to quantify pain at 6, 12, 18, 24, 36, 48, and 72 hours postoperatively. Patient satisfaction was assessed, along with side effects in both groups. VAS pain scores differed significantly between the groups at 24 hours after the operation (p = .013). All patients in group A were satisfied with the pain control method; however, 5 patients in group B were dissatisfied (p = .001), 3 owing to severe postoperative pain and 2 owing to postoperative nausea and vomiting. An average of 0.75 and 11.40 mg pethidine per patient was used in groups A and B, respectively, for 3 days. We concluded that the combined use of ultrasound-guided PNB and PCA with ketorolac can be an effective postoperative method of pain control that can reduce opioid usage.

Double layer composite membrane for preventing tendon adhesion and promoting tendon healing

Electrospun membranes and hydrogels are widely used to prevent tendon adhesion. Hydrophobic anti-inflammatory drugs could be fully loaded on the electrospinning membrane through the electrospinning process, which can better prevent tendon adhesion. Basic fibroblast growth factor (bFGF) could promote tendon healing. However, the bioactivity of free bFGF is easily inactivated, therefore, a suitable carrier is needed. As a carrier, hydrogel has little effect on the bioactivity of the protein drugs. In this work, a poly(lactic-co-glycolic) acid (PLGA) electrospun membrane loaded with ibuprofen (IBU) was prepared and named EMI. Additionally, Methoxy poly(ethylene glycol)-block-poly(L-valine) (PEG-PLV) was synthesized. bFGF was added to the PEG-PLV solution, a hydrogel containing bFGF (PLVB) was obtained after gelling. PLVB was applied to the surface of EMI, a double-layer composite membrane named EMI-PLVB was obtained. This membrane was used to prevent Achilles tendon adhesion and promote healing. IBU and bFGF in EMI-PLVB were continuously released in vitro. The inflammatory factors at the tendon healing site were significantly reduced, and the production of type I collagen (Col- I) and type III Collagen (Col-III) at the tendon healing site was also increased in vivo. In conclusion, this double-layer composite membrane drug release system can effectively prevent tendon adhesion and promote tendon healing.

Exosomes derived from tendon stem cells promote cell proliferation and migration through the TGF β signal pathway

Tendon stem cells (TSCs) are a kind of progenitor cells found in tendon niches, which play a key role in the repair of tendon injuries. Exosomes that mediate cell communication are involved in physiological processes and various diseases, while the effect of exosomes derived from TSCs (TSC-exo) on TSCs is still unclear. The purpose of this study is to explore the effect of TSC-exo on TSCs. Analyzing the characteristics of TSC-exo, we found that the TSC-exo were enriched in a large amount of transforming growth factor β (TGF β) by western blotting. We also found that the TGF β carried by TSC-exo can effectively accelerate the proliferation and migration of TSCs. We further found that TGF β carried by TSC-exo can activate the TGF β-Smad2/3 and the ERK1/2 signaling pathway in TSCs. Furthermore, matrix metalloenzyme 2 (MMP2), a downstream molecule of Smad2, is regulated by TGF β carried by TSC-exo. Collectively, our findings provide molecular insights into TSC-exo and indicate that TSC-exo are a potential strategy for treating tendon injuries.

Small molecule antagonist of C-C chemokine receptor 1 (CCR1) reduces disc inflammation in the rabbit model

BACKGROUND CONTEXT

Targeting chemokines or chemokine receptors is a promising treatment strategy for diseases with chronic inflammation such as rheumatoid arthritis and discogenic pain. Identifying specific molecules and determining their effectiveness in animal models are the first steps in developing these treatments. Macrophage markers have been detected in the intervertebral disc tissues of patients with disc degenerative disease and discogenic pain and in different animal models. Macrophage recruitment into the disc may play a role in initiation of inflammation and if unresolved may lead to chronic inflammation and subsequent back pain.

PURPOSE

The objectives of these studies are to (1) identify chemokine receptor antagonists that can block macrophage migration induced by disc cells in vitro and (2) determine if intradiscal treatment with these antagonists can reduce disc inflammation and degeneration in vivo.

STUDY DESIGN

In vitro migration assays were used to test effectiveness of chemokine receptor antagonists to block macrophage migration induced by disc cells. The rabbit annular puncture model was used to test for anti-inflammatory and regenerative effects of chemokine receptor antagonist treatment in vivo.

METHODS

In vitro - THP-1 human monocytic cell line and freshly isolated rabbit primary splenocytes were assayed for migration using 3 µm Corning Transwell inserts with conditioned media of interleukin (IL)-1β treated human or rabbit disc cells. Inhibition of macrophage migration was evaluated using different concentrations of small molecule antagonists of C-C chemokine receptor (CCR)1 and CCR2. In vivo - New Zealand White rabbits (n=40) underwent disc puncture and intradiscal treatment with saline, CCR1 or CCR2 antagonists within the same procedure. X-ray and magnetic resonance (MR) images and serum samples were taken for disc height, MRI grade and IL-8 serum level analyses. Intervertebral discs were isolated for RNA analysis of inflammatory and disc phenotypic markers and for immunohistochemical analysis of macrophage marker, RAM11. The outcome measures were compared between the three treatment groups. These studies were funded by a research grant from AO Foundation, Switzerland (Project no S-14-86A; 120000 CHF). CCR1 and CCR2 antagonists were kindly provided by ChemoCentryx (Mountain View, CA).

RESULTS

In vitro migration assays showed that THP-1 migration induced by disc cells was blocked by CCR2 antagonist more effectively than CCR1 antagonist, while rabbit splenocyte migration was inhibited by CCR1 antagonist and not the other. In the rabbit annular puncture model, rabbit discs treated with CCR1 antagonist had significantly better MRI grades than those treated with CCR2 antagonist at 6 weeks post-treatment. Gene expression studies demonstrate that discs treated with CCR1 or CCR2 antagonists expressed less inflammatory markers than saline-treated discs at 3 weeks post-treatment. Although CCR2 antagonist treatment did not reduce inflammatory marker expression at 6 weeks, discs treated with CCR1 antagonist expressed less inflammatory markers and also a higher ratio of collagen type 2 to collagen type 1 genes indicating favorable disc matrix production. There were no significant differences between all three treatment groups in regards to disc height indexes, IL-8 serum levels or macrophage marker detection.

CONCLUSIONS

These studies have identified that small molecule antagonists against CCR2 and CCR1 were respectively effective in blocking THP-1 and rabbit splenocyte migration induced by disc cells in vitro. Further, both CCR2 and CCR1 antagonist intradiscal treatments were effective in reducing disc inflammation at an early time point of 3 weeks. Lastly, only CCR1 antagonist demonstrated anti-inflammatory effects and better MRI grades at 6 weeks.

CLINICAL SIGNIFICANCE

Our preclinical studies demonstrate that CCR1 and CCR2 antagonist delivery through intradiscal injection is sufficient to reduce disc inflammation at early time points, whereas CCR1 antagonists had longer term anti-inflammatory effects. Clinical studies have found that CCR1 antagonist was safe, tolerable and clinically active in reducing inflammation in rheumatoid arthritis patients. These studies suggest that CCR1 antagonist may be a promising biological treatment to reduce disc inflammation that translates to back pain relief.

Localized delivery of ibuprofen via a bilayer delivery system (BiLDS) for supraspinatus tendon healing in a rat model

The high prevalence of tendon retear following rotator cuff repair motivates the development of new therapeutics to promote improved tendon healing. Controlled delivery of non-steroidal anti-inflammatory drugs to the repair site via an implanted scaffold is a promising option for modulating inflammation in the healing environment. Furthermore, biodegradable nanofibrous delivery systems offer an optimized architecture and surface area for cellular attachment, proliferation, and infiltration while releasing soluble factors to promote tendon regeneration. To this end, we developed a bilayer delivery system (BiLDS) for localized and controlled release of ibuprofen (IBP) to temporally mitigate inflammation and enhance tendon remodeling following surgical repair by promoting organized tissue formation. In vitro evaluation confirmed the delayed and sustained release of IBP from Labrafil-modified poly(lactic-co-glycolic) acid microspheres within sintered poly(ε-caprolactone) electrospun scaffolds. Biocompatibility of the BiLDS was demonstrated with primary Achilles tendon cells in vitro. Implantation of the IBP-releasing BiLDS at the repair site in a rat rotator cuff injury and repair model led to decreased expression of proinflammatory cytokine, tumor necrotic factor-α, and increased anti-inflammatory cytokine, transforming growth factor-β1. The BiLDS remained intact for mechanical reinforcement and recovered the tendon structural properties by 8 weeks. These results suggest the therapeutic potential of a novel biocompatible nanofibrous BiLDS for localized and tailored delivery of IBP to mitigate tendon inflammation and improve repair outcomes. Future studies are required to define the mechanical implications of an optimized BiLDS in a rat model beyond 8 weeks or in a larger animal model.

Assessment, Quantification, and Management of Fracture Pain: from Animals to the Clinic

PURPOSE OF REVIEW

Fractures are painful and disabling injuries that can occur due to trauma, especially when compounded with pathologic conditions, such as osteoporosis in older adults. It is well documented that acute pain management plays an integral role in the treatment of orthopedic patients. There is no current therapy available to completely control post-fracture pain that does not interfere with bone healing or have major adverse effects. In this review, we focus on recent advances in the understanding of pain behaviors post-fracture.

RECENT FINDINGS

We review animal models of bone fracture and the assays that have been developed to assess and quantify spontaneous and evoked pain behaviors, including the two most commonly used assays: dynamic weight bearing and von Frey testing to assess withdrawal from a cutaneous (hindpaw) stimulus. Additionally, we discuss the assessment and quantification of fracture pain in the clinical setting, including the use of numeric pain rating scales, satisfaction with pain relief, and other biopsychosocial factor measurements. We review how pain behaviors in animal models and clinical cases can change with the use of current pain management therapies. We conclude by discussing the use of pain behavioral analyses in assessing potential therapeutic treatment options for addressing acute and chronic fracture pain without compromising fracture healing. There currently is a lack of effective treatment options for fracture pain that reliably relieve pain without potentially interfering with bone healing. Continued development and verification of reliable measurements of fracture pain in both pre-clinical and clinical settings is an essential aspect of continued research into novel analgesic treatments for fracture pain.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) and Their Effect on Musculoskeletal Soft-Tissue Healing: A Scoping Review

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are being increasingly employed as a part of multimodal non-opioid strategies to treat postoperative pain. In the present study, we sought to review the effects of short-term NSAID use on musculoskeletal soft-tissue healing.

METHODS

We performed a scoping review of all studies that included the use of NSAIDs and their effect on healing of soft tissues, which for the purpose of this review refers to non-osseous musculoskeletal tissue such as ligament, tendon, labrum, and meniscus. The inclusion criteria encompassed all studies (human, animal, and in vitro) that evaluated the effect of NSAIDs on soft-tissue healing. Subgroup analyses, wherever applicable, were conducted on the basis of the type of NSAID (cyclooxygenase [COX]-specific or nonspecific) and the type of study (human, animal, or in vitro). Relevant metadata from each study were abstracted, and descriptive statistics were used to summarize the results.

RESULTS

A total of 44 studies met the inclusion criteria, including 3 human studies, 33 animal studies, and 8 in vitro studies. These studies included 4 different NSAIDs in the human subgroup, 16 different NSAIDs in the animal subgroup, and 7 different NSAIDs in the in vitro subgroup. The majority of reported studies (including 1 of 2 human studies, 10 of 14 animal studies, and 3 of 3 in vitro studies) demonstrated that COX-2-selective inhibitors had negative impact on soft-tissue healing. In contrast, the majority of human and animal studies (2 of 2 and 19 of 30, respectively) demonstrated that nonselective COX inhibitors had no negative effect on the healing of labrum, tendons, and ligaments. The majority of in vitro studies demonstrated that NSAIDs have a harmful effect on biological processes involved in tendon-healing and regeneration (tenocyte proliferation, collagen and glycosaminoglycan synthesis).

CONCLUSIONS

Current limited evidence demonstrates that selective COX-2 inhibitors can negatively affect healing of musculoskeletal soft tissue after surgical repair. In contrast, the majority of studies demonstrate that nonselective COX inhibitors have no negative effect on musculoskeletal soft-tissue healing. Additional high-quality human clinical trials are necessary to provide more definitive conclusions.

Deficiency of the SMOC2 matricellular protein impairs bone healing and produces age-dependent bone loss

Secreted extracellular matrix components which regulate craniofacial development could be reactivated and play roles in adult wound healing. We report a patient with a loss-of-function of the secreted matricellular protein SMOC2 (SPARC related modular calcium binding 2) presenting severe oligodontia, microdontia, tooth root deficiencies, alveolar bone hypoplasia, and a range of skeletal malformations. Turning to a mouse model, Smoc2-GFP reporter expression indicates SMOC2 dynamically marks a range of dental and bone progenitors. While germline Smoc2 homozygous mutants are viable, tooth number anomalies, reduced tooth size, altered enamel prism patterning, and spontaneous age-induced periodontal bone and root loss are observed in this mouse model. Whole-genome RNA-sequencing analysis of embryonic day (E) 14.5 cap stage molars revealed reductions in early expressed enamel matrix components (Odontogenic ameloblast-associated protein) and dentin dysplasia targets (Dentin matrix acidic phosphoprotein 1). We tested if like other matricellular proteins SMOC2 was required for regenerative repair. We found that the Smoc2-GFP reporter was reactivated in adjacent periodontal tissues 4 days after tooth avulsion injury. Following maxillary tooth injury, Smoc2^−/− mutants had increased osteoclast activity and bone resorption surrounding the extracted molar. Interestingly, a 10-day treatment with the cyclooxygenase 2 (COX2) inhibitor ibuprofen (30 mg/kg body weight) blocked tooth injury-induced bone loss in Smoc2^−/− mutants, reducing matrix metalloprotease (Mmp)9. Collectively, our results indicate that endogenous SMOC2 blocks injury-induced jaw bone osteonecrosis and offsets age-induced periodontal decay.

Cross-Cultural Comparison of Nonopioid and Multimodal Analgesic Prescribing in Orthopaedic Trauma

BACKGROUND

After musculoskeletal injury, US providers prescribe opioids more frequently and at higher dosages than prescribers in the Netherlands and Haiti; however, the extent of variation in nonopioid analgesic prescribing is unknown. The aim of our study was to evaluate how nonopioid prescribing by orthopaedic residents varies by geographic context.

METHODS

Orthopaedic residents in three countries in which residents are the primary prescribers of postoperative analgesia in academic medical centers (Haiti, the Netherlands, and the United States) responded to surveys using vignette-based musculoskeletal trauma case scenarios. The residents chose which medications they would prescribe for postdischarge analgesia. We quantified the likelihood and dose of acetaminophen or a nonsteroidal anti-inflammatory drug prescription. We constructed multivariable regressions with generalized estimating equations to describe differences in nonopiate prescription according to country, the resident's sex and training year, and the injury site and age in the test cases.

RESULTS

Compared with residents from the United States, residents from Haiti were more likely to prescribe nonopioids (odds ratio, 3.22 [confidence interval, 1.94 to 5.34], P < 0.0001) and residents from the Netherlands nearly always prescribed nonopioids. Of those cases where one or more opioid was prescribed, providers also prescribed a nonopioid (acetaminophen or nonsteroidal anti-inflammatory drug) in 345/603 (57.2%) of US, 152/152 (100%) of Dutch, and 69/97 (71.1%) of Haitian cases (Fisher exact test P value <0.0001). Finally, providers prescribed only nonopioids for pain control in 3/348 (0.86%) of US, 32/184 (17.4%) of Dutch, and 107/176 (60.8%) of Haitian cases (Fisher exact test P < 0.0001).

CONCLUSIONS

When comparing multimodal analgesic patterns, US prescribers prescribed nonopioid analgesics less frequently than prescribers in two other countries, one low income and one high income, either in isolation or in conjunction with opioids.

Sacral Insufficiency Fractures: a Review of Risk Factors, Clinical Presentation, and Management

PURPOSE OF THE REVIEW

Sacral insufficiency fractures (SIF) are a common and often underdiagnosed source of low back pain. In patients with SIF, there is both a compromised sacroiliac joint and weakened sacrum, resulting in decreased resistance to torsional stress, leading to fracture. While conservative medical management is a safe option, minimally invasive intervention may provide improved short and long-term relief of low back pain in patients presenting with SIF. This comprehensive review is undertaken to provide an update to the current understanding of SIF with description of risk factors, clinical presentation, and management.

RECENT FINDINGS

Sacroplasty is a minimally invasive procedure in which polymethylmethacrylate (PMMA) cement is inserted into bone to improve its structural integrity and alleviate symptoms. Balloon sacroplasty (BSP) has also been successful in alleviating pain with minimal cement leakage in SIF patients. Various other interventional techniques, including navigation-assisted screw fixation have been used to address SIF and have shown improvement in pain with minimal side effects. This review included various modalities of treatments available to manage SIF. This review shows that in comparison with nonsurgical management, sacroplasty has been shown to have greater pain reduction and improved mobility.

Chronotherapy of Non-Steroidal Anti-Inflammatory Drugs May Enhance Postoperative Recovery

Postoperative pain relief is crucial for full recovery. With the ongoing opioid epidemic and the insufficient effect of acetaminophen on severe pain; non-steroidal anti-inflammatory drugs (NSAIDs) are heavily used to alleviate this pain. However, NSAIDs are known to inhibit postoperative healing of connective tissues by inhibiting prostaglandin signaling. Pain intensity, inflammatory mediators associated with wound healing and the pharmacological action of NSAIDs vary throughout the day due to the circadian rhythm regulated by the clock genes. According to this rhythm, most of wound healing mediators and connective tissue formation occurs during the resting phase, while pain, inflammation and tissue resorption occur during the active period of the day. Here we show, in a murine tibia fracture surgical model, that NSAIDs are most effective in managing postoperative pain, healing and recovery when drug administration is limited to the active phase of the circadian rhythm. Limiting NSAID treatment to the active phase of the circadian rhythm resulted in overexpression of circadian clock genes, such as Period 2 (Per2) at the healing callus, and increased serum levels of anti-inflammatory cytokines interleukin-13 (IL-13), interleukin-4 (IL-4) and vascular endothelial growth factor. By contrast, NSAID administration during the resting phase resulted in severe bone healing impairment.

Short-term perioperative parecoxib is not detrimental to shaft fracture healing in a rat model

Objectives

Experimental studies indicate that non-steroidal anti-inflammatory drugs (NSAIDs) may have negative effects on fracture healing. This study aimed to assess the effect of immediate and delayed short-term administration of clinically relevant parecoxib doses and timing on fracture healing using an established animal fracture model.

Methods

A standardized closed tibia shaft fracture was induced and stabilized by reamed intramedullary nailing in 66 Wistar rats. A ‘parecoxib immediate’ (Pi) group received parecoxib (3.2 mg/kg bodyweight twice per day) on days 0, 1, and 2. A ‘parecoxib delayed’ (Pd) group received the same dose of parecoxib on days 3, 4, and 5. A control group received saline only. Fracture healing was evaluated by biomechanical tests, histomorphometry, and dual-energy x-ray absorptiometry (DXA) at four weeks.

Results

For ultimate bending moment, the median ratio between fractured and non-fractured tibia was 0.61 (interquartile range (IQR) 0.45 to 0.82) in the Pi group, 0.44 (IQR 0.42 to 0.52) in the Pd group, and 0.50 (IQR 0.41 to 0.75) in the control group (n = 44; p = 0.068). There were no differences between the groups for stiffness, energy, deflection, callus diameter, DXA measurements (n = 64), histomorphometrically osteoid/bone ratio, or callus area (n = 20).

Conclusion

This study demonstrates no negative effect of immediate or delayed short-term administration of parecoxib on diaphyseal fracture healing in rats.

Cite this article: G. A. Hjorthaug, E. Søreide, L. Nordsletten, J. E. Madsen, F. P. Reinholt, S. Niratisairak, S. Dimmen. Short-term perioperative parecoxib is not detrimental to shaft fracture healing in a rat model. Bone Joint Res 2019;8:472–480. DOI: 10.1302/2046-3758.810.BJR-2018-0341.R1.

Prostaglandin D2 signaling is not involved in the recovery of rat hind limb tendons from injury

Injured tendons heal through the formation of a fibrovascular scar that has inferior mechanical properties compared to native tendon tissue. Reducing inflammation that occurs as a result of the injury could limit scar formation and improve functional recovery of tendons. Prostaglandin D2 (PGD2 ) plays an important role in promoting inflammation in some injury responses and chronic disease processes, and the inhibition of PGD2 has improved healing and reduced disease burden in animal models and early clinical trials. Based on these findings, we sought to determine the role of PGD2 signaling in the healing of injured tendon tissue. We tested the hypothesis that a potent and specific inhibitor of hematopoietic PGD synthase (HPGDS), GSK2894631A, would improve the recovery of tendons of adult male rats following an acute tenotomy and repair. To test this hypothesis, we performed a full-thickness plantaris tendon tenotomy followed by immediate repair and treated rats twice daily with either 0, 2, or 6 mg/kg of GSK2894631A. Tendons were collected either 7 or 21 days after surgical repair, and mechanical properties of tendons were assessed along with RNA sequencing and histology. While there were some differences in gene expression across groups, the targeted inhibition of HPGDS did not impact the functional repair of tendons after injury, as HPGDS expression was surprisingly low in injured tendons. These results indicate that PGD2 signaling does not appear to be important in modulating the repair of injured tendon tissue.

BIOLOGICAL ENHANCEMENTS FOR ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

The anterior cruciate ligament (ACL) is mostly responsible for providing knee stability. ACL injury has a marked effect on daily activities, causing pain, dysfunction, and elevated healthcare costs. ACL reconstruction (ACLR) is the standard treatment for this injury. However, despite good results, ACLR is associated with a significant rate of failure. In this context, the mechanical and biological causes must be considered. From a biological perspective, the ACLR depends on the osseointegration of the graft in the adjacent bone and the process of intra-articular ligamentization for good results. Here, we discuss the mechanisms underlying the normal graft healing process after ACLR and its biological modulation, thus, presenting novel strategies for biological enhancements of the ACL graft. Level of evidence III, Systematic review of level III studies.

Disruption of Neutrophil Extracellular Traps (NETs) Links Mechanical Strain to Post-traumatic Inflammation

Inflammation after trauma is both critical to normal wound healing and may be highly detrimental when prolonged or unchecked with the potential to impair physiologic healing and promote de novo pathology. Mechanical strain after trauma is associated with impaired wound healing and increased inflammation. The exact mechanisms behind this are not fully elucidated. Neutrophil extracellular traps (NETs), a component of the neutrophil response to trauma, are implicated in a range of pro-inflammatory conditions. In the current study, we evaluated their role in linking movement and inflammation. We found that a link exists between the disruption and amplification of NETs which harbors the potential to regulate the wound's response to mechanical strain, while leaving the initial inflammatory signal necessary for physiologic wound healing intact.

Retrospective study of the use of medication and supplements during the 2018 FIFA World Cup Russia

Objective

Examine the intake of medication and supplements used by top-level players during the 2018 FIFA World Cup Russia.

Participants

736 top-level players

Setting

The team doctors uploaded a list of the medications used by each player to the online reporting tool within 72 hours of each match of the 2018 FIFA World Cup Russia.

Outcome measures

Average number of medications used per player per match and during the tournament; average number and percentage of players using at least one medication per match and during the tournament.

Results

54% of the players took at least one medication during the tournament and 39% took at least one medication before each match. The most used medications were non-steroidal anti-inflammatory drug (NSAID) (38.6%), followed by other analgesics (13.8%) and medications for insomnia and anxiety (13%). On average, 0.72 medications were taken per player per match and 1.32 per player during the tournament. The mean number of medication intake per player per match was higher during the knockout stage compared with the group stage (0.88±1.36 vs 0.65±1.08, p<0.001). Players from South America and North and Central America took more medications per match compared with the players from Africa (0.9±1.14 and 0.98±1.1 vs 0.48±0.83, p<0.001 in both cases).

Conclusion

The intake of NSAIDs decreased during the 2018 FIFA World Cup compared with previous FIFA World Cups, but stayed at a high level. The high number of medications taken is a cause for concern, and therefore, players, medical staff and coaches should be made more aware of the possible side effects of a high medication intake.

The impact of proton pump inhibitors on bone regeneration and implant osseointegration

Proton pump inhibitors (PPIs) have become known for the treatment of gastric-acid related disorders. Similar to any other drugs, PPIs have possible adverse reactions, being associated with bone fractures, infections, kidney disease, mineral deficiency, dementia, and pneumonia. Multiple analyses have stated that PPIs therapy may affect bone regeneration and osseointegration process, causing an increased risk of bone fracture, deterioration of bone metabolism and impaired bone healing. In this review, we emphasized the current literature regarding the influence of proton pump inhibitors in the bone regeneration process. Results from the studies suggest a link between PPIs intake and bone regeneration, but several concerns are raised regarding inadequate recipient bone, surgical trauma, limitations on the titanium surface, comorbidities or interference with other pharmacological agents. Further studies are needed to determine whether the impaired bone regeneration process is due to PPI or coexisting factors.

Effects on postoperative nausea and vomiting of nefopam versus fentanyl following bimaxillary orthognathic surgery: a prospective double-blind randomized controlled trial

Background

Postoperative nausea and vomiting (PONV) frequently occurs following bimaxillary orthognathic surgeries. Compared to opioids, Nefopam is associated with lower incidences of PONV, and does not induce gastrointestinal tract injury, coagulopathy, nephrotoxicity, or fracture healing dysfunction, which are common side effects of Nonsteroidal anti-inflammatory drugs. We compared nefopam- and fentanyl-induced incidence of PONV in patients with access to patient-controlled analgesia (PCA) following bimaxillary orthognathic surgeries.

Methods

Patients undergoing bimaxillary orthognathic surgeries were randomly divided into nefopam and fentanyl groups. Nefopam 120 mg or fentanyl 700 µg was mixed with normal saline to a final volume of 120 mL. Patients were given access to nefopam or fentanyl via PCA. Postoperative pain intensity and PONV were measured at 30 minutes and 1 hour after surgery in the recovery room and at 8, 24, 48, and 72 hours after surgery in the ward. The frequency of bolus delivery was compared at each time point.

Results

Eighty-nine patients were enrolled in this study, with 48 in the nefopam (N) group and 41 in the fentanyl (F) group. PONV occurred in 13 patients (27.7%) in the N group and 7 patients (17.1%) in the F group at 8 hours post-surgery (P = 0.568), and there were no significant differences between the two groups at any of the time points. VAS scores were 4.4 ± 2.0 and 3.7 ± 1.9 in the N and F groups, respectively, at 8 hours after surgery (P = 0.122), and cumulative bolus delivery was 10.7 ± 13.7 and 8.6 ± 8.5, respectively (P = 0.408). There were no significant differences in pain or bolus delivery at any of the remaining time points.

Conclusion

Patients who underwent bimaxillary orthognathic surgery and were given nefopam via PCA did not experience a lower rate of PONV compared to those that received fentanyl via PCA. Furthermore, nefopam and fentanyl did not provide significantly different postoperative pain control.

Effect of the lipoxygenase inhibitor baicalein on bone tissue and bone healing in ovariectomized rats

BACKGROUND

Osteoporosis is one of the world's major medical burdens in the twenty-first century. Pharmaceutical intervention currently focusses on decelerating bone loss, but phytochemicals such as baicalein, which is a lipoxygenase inhibitor, may rescue bone loss. Studies evaluating the effect of baicalein in vivo are rare.

METHODS

We administered baicalein to sixty-one three-month-old female Sprague-Dawley rats. They were divided into five groups, four of which were ovariectomized (OVX) and one non-ovariectomized (NON-OVX). Eight weeks after ovariectomy, bilateral tibial osteotomy with plate osteosynthesis was performed and bone formation quantified. Baicalein was administered subcutaneously using three doses (C1: 1 mg/kg BW; C2: 10 mg/kg BW; and C3: 100 mg/kg BW) eight weeks after ovariectomy for four weeks. Finally, femora and tibiae were collected. Biomechanical tests, micro-CT, ashing, histological and gene expression analyses were performed.

RESULTS

Biomechanical properties were unchanged in tibiae and reduced in femora. In tibiae, C1 treatment enhanced callus density and cortical width and decreased callus area. In the C3 group, callus formation was reduced during the first 3 weeks after osteotomy, correlating to a higher mRNA expression of Osteocalcin, Tartrate-resistant acid phosphatase and Rankl. In femora, baicalein treatments did not alter bone parameters.

CONCLUSIONS

Baicalein enhanced callus density and cortical width but impaired early callus formation in tibiae. In femora, it diminished the biomechanical properties and calcium-to-phosphate ratio. Thus, it is not advisable to apply baicalein to treat early bone fractures. To determine the exact effects on bone healing, further studies in which baicalein treatments are started at different stages of healing are needed.

The Influence of Naproxen on Biological Factors in Leukocyte-Rich Platelet-Rich Plasma: A Prospective Comparative Study

PURPOSE

To quantify and compare normative catabolic and anabolic factor concentrations in leukocyte-rich platelet-rich plasma (LR-PRP) at various time points, including baseline, 1 week after initiating naproxen use, and after a 1-week washout period.

METHODS

Asymptomatic healthy donors aged between 18 and 70 years were recruited (average age, 36.6 years; range, 25-64 years). Subjects were excluded from the study if they were actively taking any prescribed medications or nonsteroidal anti-inflammatory drugs (NSAIDs) or if they had any of the following at present or previously: blood or immunosuppression disorders, cancer, osteonecrosis, rheumatoid arthritis, avascular necrosis, NSAID intolerance, gastrointestinal or peptic ulcer disease, or kidney dysfunction. The anabolic factors vascular endothelial growth factor, fibroblast growth factor 2, platelet-derived growth factor AB (PDGF-AB), and platelet-derived growth factor AA (PDGF-AA) and the catabolic factors interleukin (IL) 1β, IL-6, IL-8, and tumor necrosis factor α in LR-PRP were measured. Peripheral blood was drawn at 3 time points: baseline, after 1 week of naproxen use, and after a 1-week washout period.

RESULTS

The angiogenic factors PDGF-AA (44% decrease in median) and PDGF-AB (47% decrease) significantly declined from baseline (P < .05) after 1 week of naproxen use. There was a significant recovery (P < .05) of PDGF-AA (94% increase) and PDGF-AB (153% increase) levels after the 1-week washout period, with a return to baseline levels. The catabolic factor IL-6 also had a significant decline from baseline (77% decrease in median, P < .05) after 1 week of naproxen use. After a 1-week washout period, the IL-6 level was similar to the baseline level (130% increase, P < .05).

CONCLUSIONS

Naproxen use diminished several biological factors in LR-PRP; however, a 1-week washout period was sufficient for the recovery of PDGF-AA, PDGF-AB, and IL-6 to return to baseline levels. Tumor necrosis factor α, IL-1β, IL-8, vascular endothelial growth factor, and fibroblast growth factor 2 did not show differences between the 3 time points of data collection. Discontinuing NSAIDs for a minimum of 1 week before LR-PRP treatment may improve certain biological factor levels.

LEVEL OF EVIDENCE

Level II, prospective comparative study.