Inflammatory cytokine response is greater in acute tibial plafond fractures than acute tibial plateau fractures

The Relationship Between Intra-articular Fracture Energy and a Patient's Inflammatory Response

OBJECTIVES

Prior studies have demonstrated elevated inflammatory cytokine concentrations in the synovial fluid of articular fracture patients postinjury. Similarly, CT-based fracture energy measurements have been correlated with posttraumatic osteoarthritis risk after pilon fracture. The purpose of this study was to determine the associations between synovial fluid cytokine levels, fracture energy, and overall trauma to the body in articular fracture patients.

METHODS

Acute tibial plateau, tibial plafond, and rotational ankle fracture patients were prospectively enrolled from December 2011 through January 1, 2019. Synovial fluid concentrations of interleukin-1 beta, interleukin-1 receptor antagonist, IL-6, IL-8, IL-10, matrix metallopeptidase-1, MMP-3, and MMP-13 were quantified. Patient CT scans were used to calculate fracture energy. The Injury Severity Score (ISS) was used to relate cytokine levels to whole-body injury severity. Spearman rho correlation coefficients were calculated to assess the relationship between injury severity metrics and synovial fluid cytokine, chemokine, and matrix metallopeptidase concentrations.

RESULTS

Eighty-seven patients were enrolled with 42 had a tibial plateau fractures (OTA/AO 41B1-2, 41B2-14, 41B3-3, 41C1-3, 41C2-4, 41C3-16), 24 patients had a tibial plafond fracture (OTA/AO 43B1-2, 43B2-4, 43B3-5, 43C1-2, 43C2-3, 43C3-8), and 21 had a rotational ankle fracture (OTA/AO 44B1-3, 44B2-3, 44B3-6, 44C1-4, 44C2-5). Fracture energy significantly differed between fracture patterns, with ankle fractures involving substantially less fracture energy (median = 2.92 J) than plafond (10.85 J, P < 0.001) and plateau fractures (13.05 J, P < 0.001). After adjustment for multiple comparisons, MMP-3 was significantly correlated with transformed fracture energy (r = 0.41, 95% confidence interval [CI], 0.22-0.58, P < 0.001), while IL-1β was significantly correlated with the Injury Severity Score (Spearman ρ = 0.31, 95% CI, 0.08-0.49, P = 0.004).

CONCLUSIONS

Synovial fluid MMP-3 concentration was significantly correlated with CT-quantified fracture energy in intra-articular fracture patients. Given that in clinical practice fracture energy tends to correlate with posttraumatic osteoarthritis risk, MMP-3 may warrant further investigation for its role in posttraumatic osteoarthritis development after articular fracture.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Effect of inflammatory response on joint function after hip fracture in elderly patients: A clinical study

BACKGROUND

Excellent hip joint function facilitates limb recovery and improves the quality of survival. This study aimed to investigate the potential risk factors affecting postoperative joint functional activity and outcomes in elderly hip fractures patients and to provide evidence for patient rehabilitation and clinical management.

AIM

To explore the relationship between inflammatory factors and hip function and the interaction between inflammation and health after hip fracture in elderly patients.

METHODS

The elderly patients who had hip fracture surgery at our hospital between January 1, 2021, and December 31, 2022 were chosen for this retrospective clinical investigation. Patients with excellent and fair postoperative hip function had their clinical information and characteristics gathered and compared. Age, gender, fracture site, surgical technique, laboratory indices, and other variables that could have an impact on postoperative joint function were all included in a univariate study. To further identify independent risk factors affecting postoperative joint function in hip fractures, risk factors that showed statistical significance in the univariate analysis were then included in a multiple logistic regression analysis. In addition to this, we also compared other outcome variables such as visual analogue scale and length of hospital stay between the two groups.

RESULTS

A total of 119 elderly patients with hip fractures were included in this study, of whom 37 were male and 82 were female. The results of univariate logistic regression analysis after excluding the interaction of various factors showed that there was a statistically significant difference in interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP), and complement C1q (C1q) between the fair and excellent joint function groups (P < 0.05). The results of multiple logistic regression analysis showed that IL-6 > 20 pg/mL [(Odds ratio (OR) 3.070, 95%CI: 1.243-7.579], IL-8 > 21.4 pg/ mL (OR 3.827, 95%CI: 1.498-9.773), CRP > 10 mg/L (OR 2.142, 95%CI: 1.020-4.498) and C1q > 233 mg/L (OR 2.339, 95%CI: 1.094-5.004) were independent risk factors for poor joint function after hip fracture surgery (all P < 0.05).

CONCLUSION

After hip fractures in older patients, inflammatory variables are risk factors for fair joint function; therefore, early intervention to address these markers is essential to enhance joint function and avoid consequences.

Management of High-Energy Tibial Pilon Fractures

➤ Pilon fractures in the younger patient population are frequently high-energy, intra-articular injuries and are associated with devastating, long-term impacts on patient-reported outcomes and health-related quality of life, as well as high rates of persistent disability.➤ Judicious management of associated soft-tissue injury, including open fractures, is essential to minimizing complications. Optimizing medical comorbidities and negative social behaviors (e.g., smoking) should be addressed perioperatively.➤ Delayed internal fixation with interval temporizing external fixation represents the preferred technique for managing most high-energy pilon fractures presenting with characteristically substantial soft-tissue trauma. In some cases, surgeons elect to utilize circular fixation for these scenarios.➤ Although there have been treatment advances, the results have been generally poor, with high rates of posttraumatic arthritis, despite expert care.➤ Primary arthrodesis may be indicated in cases with severe articular cartilage injury that, in the opinion of the treating surgeon, is likely unsalvageable at the time of the index management.➤ The addition of intrawound vancomycin powder at the time of definitive fixation represents a low-cost prophylactic measure that appears to be effective in reducing gram-positive deep surgical site infections.

The Inflamma-type: a patient phenotype characterized by a dysregulated inflammatory response after lower extremity articular fracture

Synovial fluid was collected from 113 patients who had suffered tibial plateau (n = 48), tibial plafond (n = 29), or rotational ankle fractures (n = 36). Concentrations of IL-1β, IL-1RA, IL-6, IL-8, IL-10, and MMP-1, -3, and -13 were quantified using multiplex assays. A cluster analysis of synovial fluid biomarker concentrations was performed. Patient demographics, fracture type, Injury Severity Score (ISS), Charlson Comorbidity Index (CCI), and biomarker concentrations were compared between clusters. A subset of patients demonstrated a dysregulated inflammatory response after articular fracture including elevated pro-inflammatory cytokines and degradative enzymes previously linked to the development of post-traumatic osteoarthritis.

Greater Acute Articular Inflammatory Response in Tibial Plafond Fractures as Compared to Ankle Fractures

BACKGROUND

Several factors are thought to contribute to posttraumatic osteoarthritis (PTOA) development, including the posttraumatic inflammatory response. The purpose of this study was to compare 2 injuries at the same joint with a different severity and prognosis. This study compared the intra-articular inflammatory response after rotational ankle fracture (lower energy and less PTOA) with tibial plafond fracture (higher energy and more PTOA).

METHODS

This prospective comparative study was conducted at a level 1 trauma center between 2014-2019. Patients between 18 and 60 years of age with acute ankle or tibial plafond fractures were enrolled. Patients with preexisting ankle OA, autoimmune disease, additional injury, or open fractures were excluded. Synovial fluid aspirations were obtained within 24 hours of injury. The concentrations of interleukin (IL)-1β, IL-1 receptor antagonist (IL-1RA), IL-6, IL-8, and IL-10 and matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 were quantified.

RESULTS

Aspiration were obtained from 29 plafond fractures and 36 ankle fractures. Mean age was 43 years, and patients were predominately female (64%). Age, gender, and comorbidities did not vary between cohorts. Of the plafond fractures, 13 were 43-B and 16 were 43-C injuries. Ankle fractures were predominately 44-B injuries, and 15 ankle fracture had articular impaction. IL-10, IL-1β, IL-6, IL-8, MMP-1, MMP-3, and MMP-13 were all significantly higher in acute plafond fractures as compared to acute ankle fractures.

CONCLUSION

This study compared articular inflammatory marker profiles after fractures of different severities. Several cytokines were elevated in plafond fractures as compared to ankle fractures, suggesting a greater inflammatory response with plafond fractures. Given the difference in prognosis for and higher rate of PTOA after plafond fractures, these data strengthen the case that postinjury inflammatory response plays a role in PTOA development. Given that the postinjury inflammatory response is one of the few modifiable variables of these injuries, future research in this area remains important.

LEVEL OF EVIDENCE

Level II, prospective.

Summary Report of the Arthritis Foundation and the American Orthopaedic Foot & Ankle Society's Symposium on Targets for Osteoarthritis Research: Part 2: Treatment Options

This second of a 2-part series of articles recounts the key points presented in a collaborative symposium sponsored jointly by the Arthritis Foundation and the American Orthopaedic Foot & Ankle Society with the intent to survey current treatment options for osteoarthritis (OA) of the foot and ankle. A meeting was held virtually on December 10, 2021. A group of experts were invited to present brief synopses of the current state of knowledge and research in this area. Topics were chosen by meeting organizers, who then identified and invited the expert speakers. Part 2 overviews the current treatment options, including orthotics, non-joint destructive procedures, as well as arthroscopies and arthroplasties in ankles and feet. Opportunities for future research are also discussed, such as developments in surgical options for ankle and the first metatarsophalangeal joint. The OA scientific community, including funding agencies, academia, industry, and regulatory agencies, must recognize the importance to patients of addressing the foot and ankle with improved basic, translational, and clinical research.

LEVEL OF EVIDENCE

Level V, review article/expert opinion.

Combination of Lidocaine and IL-1Ra Is Effective at Reducing Degradation of Porcine Cartilage Explants

BACKGROUND

Posttraumatic inflammation after joint injury, ranging from sprains to articular fracture, contributes to the development of arthritis, and the administration of interleukin 1 (IL-1) receptor antagonist (IL-1Ra) is a potential intervention to mitigate this response. Although IL-1Ra mitigates cartilage degenerative changes induced by IL-1, lidocaine is used for local pain management in acute joint injury. Intra-articular delivery of both drugs in combination would be a novel and possibly disease-modifying treatment. However, it is not known whether the interaction with lidocaine at clinical concentrations (1%) would alter the efficacy of IL-1Ra to protect cartilage from the catabolic effects of IL-1.

HYPOTHESIS

Treatment of articular cartilage with IL-1Ra in combination with a clinically relevant concentration of lidocaine (1%) will inhibit the catabolic effects of IL-1α in a manner similar to treatment with IL-1Ra alone.

STUDY DESIGN

Controlled laboratory study.

METHODS

Fresh porcine cartilage explants were harvested, challenged with IL-1α, and incubated for 72 hours with IL-1Ra or a combination of IL-1Ra and lidocaine. The primary outcome was total sulfated glycosaminoglycan (sGAG) release. Additional experiments assessed the effect of storage temperature and premixing of IL-1Ra and lidocaine on sGAG release. All explants were histologically assessed for cartilage degradation using a modified Mankin grading scale.

RESULTS

The combination of IL-1Ra and lidocaine, premixed at various time points and stored at room temperature or 4°C, was as effective as IL-1Ra alone at inhibiting IL-1α-mediated sGAG release. Mankin histopathology scores supported these findings.

CONCLUSION

Our hypothesis was supported, and results indicated that the combination of IL-1Ra and lidocaine was as efficacious as IL-1Ra treatment alone in acutely mitigating biological cartilage injury due to IL-1α in an explant model.

CLINICAL SIGNIFICANCE

The combination of IL-1Ra and lidocaine is stable when reagents are stored in advance of administration at varying temperatures, providing clinically relevant information about storage of medications. The ability to premix and store this drug combination for intra-articular delivery may provide a novel treatment after joint injury to provide pain relief and block inflammation-induced catabolism of joint tissues.

Fracture and Patient Characteristics Associated With Early Conversion Total Hip Arthroplasty After Acetabular Fracture Fixation

OBJECTIVES

To determine risk factors for early conversion total hip arthroplasty (THA) after operative treatment of acetabular fractures.

DESIGN

Retrospective cohort.

SETTING

Level I trauma center.

PATIENTS AND INTERVENTION

We reviewed 685 operative acetabular fractures at our institution from 2011 to 2017, with a median follow-up of 12 months (range, 4-105 months).

MAIN OUTCOME MEASURE

Multivariable regression analysis was performed after univariate analysis to identify independent risk factors for conversion THA. Sensitivity analysis was performed with minimum follow-up set at 6 and 12 months.

RESULTS

One hundred eight patients (16%) underwent conversion THA, with 52% of conversions occurring within 1 year, an additional 27% within 2 years, and the remaining 21% within 6 years of the index acetabular open reduction internal fixation. The median time to conversion THA was 11.5 months (range, 0.5-72 months). The risk of conversion THA by fracture pattern was 53 of 196 (27%) for transverse posterior wall (TPW), 12 of 52 (23%) for T shaped, 10 of 68 (15%) for posterior column with posterior wall, and 25 of 207 (12%) for posterior wall. Independent risk factors for early conversion included the following: TPW fracture, protrusio, hip dislocation, increased body mass index, increased age, infection, and dislocation after open reduction internal fixation. Independent risk factors for early conversion THA specific to patients with TPW fractures include only increased age and body mass index. Sensitivity analysis showed no change in results using either 6 or 12-month minimum follow-up.

CONCLUSION

Transverse posterior wall fractures have a high risk of early conversion THA compared with other acetabular fracture patterns, especially when in combination with other significant risk factors. Consideration for different and novel management options warrants further study in this subset of acetabular fracture patients.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Degenerative joint changes following intra-articular fracture are more severe in mice with T cell deficiency

The inflammatory response to joint injury, specifically intra-articular fracture, has been implicated in posttraumatic arthritis development. However, the role of T cells in regulating the development of posttraumatic arthritis is unclear. We hypothesized that the absence of T cells would lead to less severe posttraumatic arthritis following intra-articular fracture. T cell-deficient, athymic nude, and wild-type C57BL/6NJ mice were assessed at 8 weeks following closed articular fracture. Joints were assessed using histologic scores of arthritis, synovitis, and bone morphology via micro computed tomography. Cells were profiled in whole blood via flow cytometry, and plasma and synovial fluid derived cytokines were quantified by multiplex analysis. Compared to C57BL/6NJ mice, nude mice had significantly greater histologic evidence of arthritis and synovitis. Whole blood immune cell profiling revealed a lower percentage of dendritic cells but increased natural killer (NK) cells in nude mice. Concurrently, nude mice had significantly higher levels of NK cells in synovial tissue. Concentrations of plasma interleukin 1β (IL-1β) and tumor necrosis factor α, and synovial fluid IL-12, IL-17, and IL-6 in both knees were greater in nude mice. Outcomes of this study suggest that T cells may play a protective regulatory role against the development of posttraumatic arthritis. Clinical significance: Lack of functional T cells exacerbated the development of posttraumatic arthritis following intra-articular fracture suggesting that critical regulators of the immune responses, contained within the T cell population, are required for protection. Future research identifying the specific T cell subsets responsible for modulating disease immunopathogenesis will lead to new therapeutic targets to mitigate posttraumatic arthritis.

Inflammatory cytokines and matrix metalloproteinases in the synovial fluid after intra-articular elbow fracture

BACKGROUND AND HYPOTHESIS

Post-traumatic elbow contracture remains a common and challenging complication with often unsatisfactory outcomes. Although the etiology is unknown, elevated or abnormal post-fracture synovial fluid cytokine levels may result in the migration of fibroblasts to the capsule and contribute to capsular pathology. Thus, the purpose of this study was to characterize the cytokine composition in the synovial fluid fracture hematoma of patients with intra-articular elbow fractures.

METHODS

The elbow synovial fluid fracture hematoma of 11 patients with intra-articular elbow fractures was analyzed for CTXII (C-terminal telopeptides of type II collagen [a cartilage breakdown product]) as well as 15 cytokines and matrix metalloproteinases (MMPs) including interferon γ, interleukin (IL) 1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, tumor necrosis factor α, MMP-1, MMP-2, MMP-3, MMP-9, and MMP-10. The uninjured, contralateral elbow served as a matched control. Mean concentrations of each factor were compared between the fluid from fractured elbows and the fluid from control elbows.

RESULTS

The levels of 14 of 15 measured cytokines and MMPs-interferon γ, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, tumor necrosis factor α, MMP-1, MMP-3, MMP-9, and MMP-10-were significantly higher in the fractured elbows. In addition, post hoc power analysis revealed that 10 of 14 significant differences were detected with greater than 90% power. The mean concentration of CTXII was not significantly different between groups.

CONCLUSIONS

These results demonstrate a proinflammatory environment after fracture that may be the catalyst to the development of post-traumatic elbow joint contracture. The cytokines with elevated levels were similar, although not identical, to the cytokines with elevated levels in studies of other weight-bearing joints, indicating the elbow responds uniquely to trauma.