Primary Closure of External Fixator Pin Sites Is Safe After Orthopaedic Trauma Surgery.

OBJECTIVES: To determine if rates of pin site infection and surgical site infection among patients managed with primary closure after external fixator removal were similar to those allowed to heal secondarily. DESIGN: Retrospective cohort. SETTING: Urban/Suburban Academic Level I Trauma Center. PATIENT SELECTION CRITERIA: Patients who had received a lower extremity external fixator for provisional management before definitive fixation of lower extremity fractures were included with pin site wounds closed primarily or allowed to heal by secondary intention. OUTCOME MEASURES AND COMPARISONS: The rate of pin tract infection and surgical site infection following primary closure of external fixator pin sites relative to patients whose pin sites were allowed to heal through secondary intention. RESULTS: In total, 256 patients were evaluated: 143 patients (406 pin sites) in the primary closure group and 113 patients (340 in sites) in the secondary closure group. The average age was 49 ± 16 years. Sixty-five percent of included patients were male. There was no difference in pin tract infections between cohorts (primary = 0.5%, secondary = 1.5%, P = 0.26). External fixator duration in the primary closure group was 11.5 ± 8.4 days and 13.0 ± 8.1 days in the secondary closure group (P = 0.15). There was a greater rate of surgical site infections in the secondary intention cohort (15.9% vs. 7.7%, P = 0.047). CONCLUSIONS: There was no difference in pin site infection rate after primary pin site closure relative to patients who were allowed to heal through secondary intention. Furthermore, there was a lower rate of surgical site infection after primary closure. These results challenge the dogma of secondary closure for ex fix pin sites, suggesting that debridement and primary closure is a safe option for management of external fixator pin sites and may impart benefit in decreasing infection risk. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Adjunctive dorsal spanning plate fixation for challenging distal radius injuries.

Background: Distal radius fractures with severely osteoporotic bone or articular comminution can provide challenges to fixation with traditional volar locked plating alone. The purpose of this study was to evaluate the clinical, radiographic, and patient reported outcomes of patients undergoing distal radius fixation with volar locked plating and adjunctive dorsal bridge plating. Methods: We retrospectively identified 16 patients with distal radius fractures who underwent our preferred surgical technique for fixation. Patients underwent volar locked plate fixation as well as dorsal bridge fixation at time of surgery. Seven patients were indicated for severe articular comminution with volar rim fragmentation (44%), three patients were revised for nonunion after previous volar locked late fixation (19%), and six patients had severely osteoporotic bone with articular comminution (38%). Two patients (13%) sustained AO/OTA 23-A3 distal radius fracture, two patients (13%) had a 23-B3 fracture, two patients (13%) had a 23-C2 fracture and ten patients (63%) had a 23-C3 fracture. Results: The average patient age was 51.8 years ± 20.6. Patients were followed for an average of 12.2±6.3 months. The dorsal bridge plate was removed at an average of 11.1±2.4 weeks. The average post-operative radial inclination was 18.9±2.4°, radial height 12.4 mm ± 2.6 mm, and volar tilt 7.1±1.9°. There were no cases of deep or superficial infection. After dorsal bridge plate removal, patients demonstrated an average wrist extension of 55.3±9.5°, flexion 54.4±12.8°, radial deviation 15.7±3.2°, 25.2±3.9 degrees of ulnar deviation. Conclusion: Distal radius fractures in the setting of severely osteoporotic bone, salvage procedures, articular comminution, volar rim fractures, and revision surgery present uniquely difficult surgical challenges. Volar locked plating with adjunctive dorsal bridge plating can be used with good short- and long-term results.

Increased Neighborhood Deprivation Is Associated with Prolonged Hospital Stays After Surgical Fixation of Traumatic Pelvic Ring Injuries.

BACKGROUND: The purpose of this study was to understand the role of social determinants of health assessed by the Area Deprivation Index (ADI) on hospital length of stay and discharge destination following surgical fixation of pelvic ring fractures. METHODS: A retrospective chart analysis was performed for all patients who presented to our level-I trauma center with pelvic ring injuries that were treated with surgical fixation. Social determinants of health were determined via use of the ADI, a comprehensive metric of socioeconomic status, education, income, employment, and housing quality. ADI values range from 0 to 100 and are normalized to a U.S. mean of 50, with higher scores representing greater social deprivation. We stratified our cohort into 4 ADI quartiles. Statistical analysis was performed on the bottom (25th percentile and below, least deprived) and top (75th percentile and above, most deprived) ADI quartiles. Significance was set at p < 0.05. RESULTS: There were 134 patients who met the inclusion criteria. Patients in the most deprived group were significantly more likely to have a history of smoking, to self-identify as Black, and to have a lower mean household income (p = 0.001). The most deprived ADI quartile had a significantly longer mean length of stay (and standard deviation) (19.2 ± 19 days) compared with the least deprived ADI quartile (14.7 ± 11 days) (p = 0.04). The least deprived quartile had a significantly higher percentage of patients who were discharged to a resource-intensive skilled nursing facility or inpatient rehabilitation facility compared with those in the most deprived quartile (p = 0.04). Race, insurance, and income were not significant predictors of discharge destination or hospital length of stay. CONCLUSIONS: Patients facing greater social determinants of health had longer hospital stays and were less likely to be discharged to resource-intensive facilities when compared with patients of lesser social deprivation. This may be due to socioeconomic barriers that limit access to such facilities. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Clinical Improvement Following Operative Management of Ankle Fractures Among Patients With and Without Moderate to High Depressive Symptoms: An Analysis Using PROMIS.

Background: Understanding the recovery trajectory following operative management of ankle fractures can help surgeons guide patient expectations. Further, it is beneficial to consider the impact of mental health on the recovery trajectory. Our study aimed to address the paucity of literature focused on understanding the recovery trajectory following surgery for ankle fractures, including in patients with depressive symptoms. Methods: From February 2015 to March 2020, patients with isolated ankle fractures were asked to complete Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF), Pain Interference (PI), and Depression questionnaires as part of routine care at presentation and follow-up time points. Linear mixed effects regression models were used to evaluate the patient recovery pattern, comparing the preoperative time point to <3 months, 3-6 months, and >6 months across all patients. Additional models that included the presence of depression symptoms as a covariate were then used. Results: A total of 153 patients met inclusion criteria. By 3-6 months, PROMIS PF (ß: 9.95, 95% CI: 7.97-11.94, P < .001), PI (ß: -10.30, 95% CI: -11.87 to -8.72, P < .001), and Depression (ß: -5.60, 95% CI: -7.01 to -4.20, P < .001) improved relative to the preoperative time point. This level of recovery was sustained thereafter. When incorporating depressive symptoms into our model as a covariate, the moderate to high depressive symptoms were associated with significantly and clinically important worse PROMIS PF (ß: -4.00, 95% CI: -7.00 to -1.00, P = .01) and PI (ß: 3.16, 95% CI: -0.55 to 5.76, P = .02) scores. Conclusion: Following ankle fracture surgery, all patients tend to clinically improve by 3-6 months postoperatively and then continue to appreciate this clinical improvement. Although patients with moderate to high depressive symptoms also clinically improve following the same trajectory, they tend to do so to a lesser level than those who have low depressive symptoms. Level of Evidence: Level III, case-control study.

Risk factors for loss of reduction following locked plate fixation of proximal humerus fractures in older adults.

PURPOSE: To identify characteristics associated with loss of reduction following open reduction and locked plate fixation (ORIF) of proximal humerus fractures in older adults and determine if loss of reduction affects patient reported outcomes (PROs), range of motion (ROM), and complication rates during the first postoperative year. METHODS: Patients >55 years old who underwent proximal humerus ORIF were reviewed. Patient and fracture characteristics were recorded. Fixation characteristics were measured on the initial postoperative AP radiograph including humeral head height (HHH) relative to the greater tuberosity (GT), head shaft angle (HSA), screw-calcar distance, and screw tip-joint surface distance. Loss of reduction was defined as GT displacement >5 mm or HSA displacement >10° on final follow up radiographs. Patient, fracture, and fixation characteristics were tested for association with loss of reduction. Outcomes including ROM, visual analog scale pain and PROMIS scores, and complication/reoperation rates during the first postoperative year were compared between those with or without loss of reduction. RESULTS: A total of 79 patients were identified, 23 (29.1%) of which had a loss of reduction. Calcar comminution (relative risk [RR]=2.5, 95% Confidence Interval [CI]=1.3-5.0, p<0.01), HHH <5 mm above GT (RR=2.0, CI=1.0-3.9, p = 0.048), and screw-calcar distance ≥12 mm (RR=2.1, CI=1.1-4.1, p = 0.03) were risk factors for loss of reduction. Upon multivariate analysis, calcar comminution was determined to be an independent risk factor for loss of reduction (RR=2.4, CI=1.2-4.7, p = 0.01). Loss of reduction led to higher complication (44% vs 13%, p<0.01) and reoperation rates (30% vs 7%, p<0.01), and decreased achievement of satisfactory ROM (>90° active forward flexion, 57% vs 82%, p = 0.02) compared to maintained reduction, but similar PROs. CONCLUSIONS: Calcar comminution, decreased HHH, and increased screw-calcar distance are risk factors for loss of reduction following ORIF of proximal humerus fractures. These morphologic and technical factors are important considerations for prolonged reduction maintenance.

Physical Function and Pain Interference Levels of Hallux Rigidus Patients Before and After Synthetic Cartilage Implant vs Arthrodesis Surgery.

BACKGROUND: Hallux rigidus is a common and painful degenerative condition of the great toe limiting a patient's physical function and quality of life. The purpose of this study was to investigate pre- and postoperative physical function (PF) and pain interference (PI) levels of patients undergoing synthetic cartilage implant hemiarthroplasty (SCI) vs arthrodesis (AD) for treatment of hallux rigidus using the Patient-Reported Outcomes Measurement Information System (PROMIS). METHODS: PROMIS PF and PI t scores were analyzed for patients who underwent either SCI or AD. Postoperative final PROMIS t scores were obtained via phone survey. Linear mixed model analysis was used to assess differences in PF and PI at each follow-up point. Final follow-up scores were analyzed using independent sample t tests. RESULTS: Total 181 (59 SCI, 122 AD) operatively managed patients were included for analysis of PROMIS scores. Final phone survey was performed at a minimum of 14 (mean 33, range, 14-59) months postoperatively, with 101 patients (40 SCI, 61 AD) successfully contacted. The mean final follow-up was significantly different for SCI and AD: 27 vs 38 months, respectively (P < .01). The mean age of the SCI cohort was lower than the AD cohort (57.5 vs 61.5 years old, P = .01). Average PF t scores were higher in the SCI cohort at baseline (47.1 and 43.9, respectively, P = .01) and at final follow-up (51.4 vs 45.9, respectively, P < .01). A main effect of superior improvement in PF was noted in the SCI group (+4.3) vs the AD group (+2) across time intervals (P < .01). PI t scores were similar between the 2 procedures across time points. CONCLUSION: The SCI cohort reported slightly superior PF t scores preoperatively and at most follow-up time points compared with the arthrodesis group. No differences were found for PI or complication rates between the 2 treatment groups during this study time frame. LEVEL OF EVIDENCE: Level IV, case series.

Tensile mechanical changes in the Achilles tendon due to Insertional Achilles tendinopathy.

Insertional Achilles tendinopathy (IAT) is a painful condition that is challenging to treat non-operatively. Although previous studies have characterized the gross histological features, in vivo strain patterns and transverse compressive mechanical properties of tissue affected by IAT, it is not known how IAT impacts the tensile mechanical properties of the Achilles tendon insertion along the axial/longitudinal direction (i.e., along the predominant direction of loading). To address this knowledge gap, the objectives of this study were to 1) apply ex vivo mechanical testing, nonlinear elastic analysis and quasilinear viscoelastic (QLV) analysis to compare the axial tensile mechanical properties of the Achilles tendon insertion in individuals with and without IAT; and 2) use biochemical analysis and second harmonic generation (SHG) imaging to assess structural and compositional changes induced by IAT in order to help explain IAT-associated tensile mechanical changes. Tissue from the Achilles tendon insertion was acquired from healthy donors and from patients undergoing debridement surgery for IAT. Tissue specimens were mechanically tested using a uniaxial tensile (stress relaxation) test applied in the axial direction. A subset of the donor specimens was used for SHG imaging and biochemical analysis. Linear and non-linear elastic analyses of the stress relaxation tests showed no significant tensile mechanical changes in IAT specimens compared to healthy controls. However, SHG analysis showed that fibrillar collagen was significantly more disorganized in IAT tissue as compared with healthy controls, and biochemical analysis showed that sulfated glycosaminoglycan (sGAG) content and water content were higher in IAT specimens. Collectively, these findings suggest that conservative interventions for IAT should target restoration of ultrastructural organization, reduced GAG content, and reduced resistance to transverse compressive strain.

Chopart Amputation: Questioning the Clinical Efficacy of a Long-standing Surgical Option for Diabetic Foot Infection.

BACKGROUND: Diabetic foot ulcers with associated infection and osteomyelitis often lead to partial or complete limb loss. Determination of the appropriate level for amputation based on the patient's baseline physical function, extent of infection, vascular patency, and comorbidities can be challenging. Although Chopart amputation preserves greater limb length than more proximal alternatives such as Syme or below-the-knee amputations (BKA), challenges with wound healing and prosthesis fitting have been reported. We aimed to investigate the functional and clinical outcomes of Chopart amputation combined with tendon transfers. METHODS: We identified patients who underwent Chopart amputations for diabetic foot infections by an academic orthopaedic group between August 2013 and September 2018. Subjects completed three Patient-Reported Outcomes Measurement Information Systems (PROMIS) instruments. Incidence of postoperative complications and change in patient-reported outcomes before and after surgery were recorded. RESULTS: Eighteen patients with an average age of 60.8 (range, 44 to 79) years were identified. The mean follow-up was 22.8 months (range, 6.7 to 51.0). Seventeen of the 18 total patients developed postoperative wound complications. These lead to revision amputations in 10 Chopart amputees, consisting of two Syme and eight BKAs. Half of the Chopart patients never received a prosthesis because of delayed wound healing and revision amputation. PROMIS physical function (PF) (31.1 pre-op and 28.6 post-op), pain interference (63.1 pre-op and 59.4 post-op), and depression (53.0 pre-op and 54.8 post-op) did not show significant change (P-values = 0.38, 0.29, 0.72, respectively). Pre- and post-op the PROMIS physical function scores were well below the US average. DISCUSSION: In our patient cohort, 94% of patients developed postoperative wound complication. Only 44% of patients ever successfully ambulated with a prosthesis after Chopart amputation, and the others (56%) required revision amputations such as a BKA. Even after wound healing, Chopart amputees may struggle with obtaining a prosthesis suitable for ambulation. Surgeons should exercise judicious patient selection before performing Chopart amputation. LEVEL OF EVIDENCE: IV, Case Series.

Aptamer based proteomic pilot study reveals a urine signature indicative of pediatric urinary tract infections.

OBJECTIVE: Current urinary tract infection (UTI) diagnostic strategies that rely on leukocyte esterase have limited accuracy. We performed an aptamer-based proteomics pilot study to identify urine protein levels that could differentiate a culture proven UTI from culture negative samples, regardless of pyuria status. METHODS: We analyzed urine from 16 children with UTIs, 8 children with culture negative pyuria and 8 children with negative urine culture and no pyuria. The urine levels of 1,310 proteins were quantified using the Somascan™ platform and normalized to urine creatinine. Machine learning with support vector machine (SVM)-based feature selection was performed to determine the combination of urine biomarkers that optimized diagnostic accuracy. RESULTS: Eight candidate urine protein biomarkers met filtering criteria. B-cell lymphoma protein, C-X-C motif chemokine 6, C-X-C motif chemokine 13, cathepsin S, heat shock 70kDA protein 1A, mitogen activated protein kinase, protein E7 HPV18 and transgelin. AUCs ranged from 0.91 to 0.95. The best prediction was achieved by the SVMs with radial basis function kernel. CONCLUSIONS: Biomarkers panel can be identified by the emerging technologies of aptamer-based proteomics and machine learning that offer the potential to increase UTI diagnostic accuracy, thereby limiting unneeded antibiotics.

Peritalar Kinematics With Combined Deltoid-Spring Ligament Reconstruction in Simulated Advanced Adult Acquired Flatfoot Deformity.

BACKGROUND: Adult acquired flatfoot deformity (AAFD) is a complex and progressive deformity involving the ligamentous structures of the medial peritalar joints. Recent anatomic studies demonstrated that the spring and deltoid ligaments form a greater medial ligament complex, the tibiocalcaneonavicular ligament (TCNL), which provides medial stability to the talonavicular, subtalar, and tibiotalar joints. The aim of this study was to assess the biomechanical effect of a spring ligament tear on the peritalar stability. The secondary aim was to assess the effect of TCNL reconstruction in restoration of peritalar stability in comparison with other medial stabilization procedures, anatomic spring or deltoid ligament reconstructions, in a cadaveric flatfoot model. METHODS: Ten fresh-frozen cadaveric foot specimens were used. Reflective markers were mounted on the tibia, talus, navicular, calcaneus, and first metatarsal. Peritalar joint kinematics were captured by a multiple-camera motion capture system. Mild, moderate, and severe flatfoot models were created by sequential sectioning of medial capsuloligament complex followed by cyclic axial loading. Spring only, deltoid only, and combined deltoid-spring ligament (TCNL) reconstructions were performed. The relative kinematic changes were compared using 2-way analysis of variance (ANOVA). RESULTS: Compared with the initial condition, we noted significantly increased valgus alignment of the subtalar joint of 5.1 ± 2.3 degrees (P = .031) and 5.8 ± 2.7 degrees (P < .01) with increased size of the spring ligament tear to create moderate to severe flatfoot, respectively. We noted an increased tibiotalar valgus angle of 5.1 ± 2.0 degrees (P = .03) in the severe model. Although all medial ligament reconstruction methods were able to correct forefoot abduction, the TCNL reconstruction was able to correct both the subtalar and tibiotalar valgus deformity (P = .04 and P = .02, respectively). CONCLUSION: The TCNL complex provided stability to the talonavicular, subtalar, and tibiotalar joints. The combined deltoid-spring ligament (TCNL) reconstructions restored peritalar kinematics better than isolated spring or deltoid ligament reconstruction in the severe AAFD model. CLINICAL RELEVANCE: The combined deltoid-spring ligament (TCNL) reconstruction maybe considered in advanced AAFD with medial peritalar instability: stage IIB with a large spring ligament tear or stage IV.

Rates and Risk Factors for Failure of Surgical Repair of the Knee Extensor Mechanism.

OBJECTIVES: To evaluate rates and risk factors for failed surgical repair of the knee extensor mechanism. DESIGN: Retrospective cohort study. SETTING: Academic medical center. PATIENTS/PARTICIPANTS: Two hundred ninety-four patients and a total of 303 extensor mechanism repairs were included. This encompassed 113 quadriceps tendon repairs (QTR), 112 fracture repairs (FR), and 68 patellar tendon repairs (PTR). MAIN OUTCOME MEASUREMENT: Repair failure. RESULTS: There were 6 failures (5%) in the QTR group, 21 failures (17%) in the FR group, and 2 failures (3%) in the PTR group. The difference in failure rates between the groups was significant (P = 0.001), but the rate of revision fixation or repair was not (P = 0.315). In the QTR group, a history of inflammatory arthritis was found to be significantly different between patients who had repair failure and patients who did not (P = 0.014) with a relative risk for failure of 17.8 (confidence interval 4.5-70.4). In the FR group, patient age (P = 0.001) and comorbid diabetes mellitus (P = 0.046) were found to be significantly different between patients with and without repair failure in univariate analysis, but only patient age (P = 0.005) was significant in multiple logistic regression analysis. The relative risk for FR failure was 6.6 (confidence interval 2.3-18.3) for age greater than 60. No risk factors for failure were identified in the PTR group. CONCLUSIONS: Overall, patients with fractures were more likely experience repair failure than patients with tendon injuries, but all patients underwent similar rates of reoperation. Inflammatory arthritis in patients with QTRs and older patient age in FRs are risk factors for repair failure. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Pattern of recovery and outcomes of patient reported physical function and pain interference after ankle fusion: a retrospective cohort study.

BACKGROUND: Research on outcomes after ankle fusion focuses on basic activities of daily living, fusion rates, and gait parameters. Little has been reported on the patient's perspective after surgery. The purpose of this study was to determine the change in patient reported physical function and pain interference after ankle fusion surgery to guide patient expectations and improve provider communication. METHODS: This was a retrospective review of prospectively collected patient reported outcome measurement information system (PROMIS) data in 88 ankle arthrodesis procedures performed from May 2015 to March 2018. The PROMIS Physical function (PF) and pain interference (PI) measures were collected as routine care. Linear mixed models were used to assess differences at each follow-up point for PF and PI. Preoperative to last follow-up in the 120-365 day interval was assessed using analysis of variance. Outcomes included T-scores, z-scores, and PROMIS-Preference (PROPr) utility scores for PF and PI and the percentage of patients improving by at least 4 T-score points. RESULTS: The linear mixed model analysis for PF after the 120-149 days, and for PI, after 90-119 days, indicated recovery plateaued at 39-40 for PF and 57-59 for PI T-scores. The change in the PI T-score was the greatest with a mean T-score improvement of - 5.4 (95% CI - 7.7 to - 3.1). The proportion of patients improving more than 4 points was 66.2% for either PF or PI or both. The change in utility T-scores for both PF (0.06, 95% CI 0.02 to 0.11) and PI (0.15, 95% CI 0.09 to 0.20) was significantly improved, however, only PI approached clinical significance. CONCLUSION: Average patients undergoing ankle fusion experience clinically meaningful improvement in pain more so than physical function. Average patient recovery showed progressive improvement in pain and function until the four-month postoperative time point. Traditional dogma states that recovery after an ankle fusion maximizes at a year, however based on the findings in this study, 4 months is a more accurate marker of recovery. A decline in function or an increase in pain after 4 months from surgery may help to predict nonunion and other complications after ankle arthrodesis. LEVEL OF EVIDENCE: Level II, prospective single cohort study.

Modern Results of Functional Bracing of Humeral Shaft Fractures: A Multicenter Retrospective Analysis.

OBJECTIVES: To evaluate the rate of, and reasons for, conversion of closed treatment of humeral shaft fractures using a fracture brace, to surgical intervention. DESIGN: Multicenter, retrospective analysis. SETTING: Nine Level 1 trauma centers across the United States. PATIENTS: A total of 1182 patients with a closed humeral shaft fracture initially managed nonoperatively with a functional brace from 2005 to 2015 were reviewed retrospectively from 9 institutions. INTERVENTION: Functional brace. MAIN OUTCOME MEASUREMENTS: Conversion to surgery. RESULTS: A total of 344 fractures (29%) ultimately underwent surgical intervention. Reasons for conversion included nonunion (60%), malalignment beyond acceptable parameters (24%), inability to tolerate functional bracing (12%), and persistent signs of radial nerve palsy requiring exploration (3.7%). Univariate comparisons showed that females and whites were significantly (P < 0.05) more likely to be converted to surgery. The multivariate logistic regression identified females as being 1.7 times more likely and alcoholics to be 1.4 times more likely to be converted to surgery (P < 0.05). Proximal shaft as well as comminuted, segmental, and butterfly fractures were also linked to a higher rate of conversion. CONCLUSIONS: This large multicenter study identified a 29% surgical conversion rate, with nonunion as the most common reason for surgical intervention after the failure of functional brace. These results are markedly different than previously reported. These results may be helpful in the future when counseling patients on the choice between functional bracing and surgical intervention in managing humeral shaft fractures. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Rethinking strategies for blood transfusion in hip fracture patients.

OBJECTIVES: Most patients can tolerate a hemoglobin (Hgb) > 8 g per deciliter. In some cases, however, transfusion will delay physical therapy and hospital discharge. This study aims to review Hgb and transfusion data for a large volume of recent hip fracture patients in order to identify new opportunities for decreasing the length of hospital stay. Our hypotheses are that in some cases, earlier transfusion of more blood will be associated with shorter hospital stays, and that Hgb levels consistently decrease for more than 3 days postoperatively. DESIGN: Retrospective chart review. SETTING: Two academic medical centers with Geriatric Fracture Programs. PATIENTS: Data was collected from patients 50 years and older with hip fractures April 2015 and October 2017. INTERVENTION: Operative stabilization of the hip fractures according to standard of care for the fracture type and patient characteristics. Transfusion according to established standards. MAIN OUTCOME MEASUREMENTS: Electronic records were retrospectively reviewed for demographic information, Hgb levels, and transfusion events. RESULTS: One thousand fifteen patients with femoral neck or intertrochanteric hip fractures were identified. Eight hundred sixty met the inclusion criteria. The average length of hospital stay was 6.7 days. The mean patient age was 82 years. The average American Society of Anesthesiologists score was 2.9. The average Hgb level consistently decreased for 5 days postoperatively before beginning to increase on day 6. There was poor consistency between intraoperative Hgb levels and preoperative or postoperative Hgb levels. Three hundred sixty-eight (42.8%) patients were transfused an average of 1.9 (range 1-6) units. One hundred five patients required a transfusion on postoperative day (POD) 1: 72 received only 1 unit of blood: 36 (50%) of the 72 required a second transfusion in the following days, compared to 9 of 33 (27%) who received 2 units on POD 1 (χ2 = 3.8898; P < .05). Patients who received transfusions on POD 3 or later had an average length of stay >2.5 days longer than those who received a transfusion earlier (P = 0.005). CONCLUSIONS: Our findings do not support earlier transfusion of more blood. Although in some cases, there is an association between earlier transfusion of more blood and shorter hospital stay, routine transfusion of more blood would incur higher transfusion risks in some patients who would not otherwise meet criteria for transfusion. After hip fracture surgery, the Hgb usually decreases for 5 days and does not begin to increase until POD 6. This information will provide utility in the population health management of hip fracture patients. LEVEL OF EVIDENCE: Level III, Retrospective Cohort Study.

Alterations in tibiotalar joint reaction force following syndesmotic injury are restored with static syndesmotic fixation.

INTRODUCTION: Syndesmotic injury alters joint mechanics, which may fail to be restored unless an anatomic reduction is obtained. METHODS: A minimally invasive method of measuring joint forces was utilized that does not require significant dissection or intraarticular placement of sensory instruments. Steinmann pins were placed in the tibia and talus of eight fresh-frozen human cadaveric lower extremities and a baseline joint reaction force was determined. A syndesmotic injury was created and reduction (anatomic and anterior malreduction) performed with one or two quadricortical screws and joint reaction forces were measured after the injury and subsequent repairs. FINDINGS: Baseline mean tibiotalar joint reaction force was 31.4 (SD 7.3 N) and syndesmotic injury resulted in a 35% decrease (mean 20.3, SD 8.4 N, p < 0.01). Fixation of the injury using one or two syndesmotic screws resulted in significant increase compared to the injury state (mean 28.7, SD3.9 N, and mean 28.3, SD 6.4 N, p < 0.05), however there was no significant difference between the two methods of fixation. Malreduction of the fibula also increased joint reaction force compared to the injury state (mean 31.5, SD 5.2 N, p < 0.01), however a significant difference was not detected between malreduction and anatomic reduction. INTERPRETATION: The present study demonstrates that syndesmotic injury decreases joint reaction force within the tibiotalar joint, suggesting ankle joint instability. Tibiotalar force was restored with anatomic reduction with either a 1 or 2 quadricortical syndesmotic screws. Furthermore, anterior malreduction restored joint reaction force to levels similar to those observed at baseline and with anatomic reduction. LEVEL OF EVIDENCE: Level V: biomechanical/cadaver study.

Chondrocyte-Specific RUNX2 Overexpression Accelerates Post-traumatic Osteoarthritis Progression in Adult Mice.

RUNX2 is a transcription factor critical for chondrocyte maturation and normal endochondral bone formation. It promotes the expression of factors catabolic to the cartilage extracellular matrix and is upregulated in human osteoarthritic cartilage and in murine articular cartilage following joint injury. To date, in vivo studies of RUNX2 overexpression in cartilage have been limited to forced expression in osteochondroprogenitor cells preventing investigation into the effects of chondrocyte-specific RUNX2 overexpression in postnatal articular cartilage. Here, we used the Rosa26Runx2 allele in combination with the inducible Col2a1CreERT2 transgene or the inducible AcanCreERT2 knock-in allele to achieve chondrocyte-specific RUNX2 overexpression (OE) during embryonic development or in the articular cartilage of adult mice, respectively. RUNX2 OE was induced at embryonic day 13.5 (E13.5) for all developmental studies. Histology and in situ hybridization analyses suggest an early onset of chondrocyte hypertrophy and accelerated terminal maturation in the limbs of the RUNX2 OE embryos compared to control embryos. For all postnatal studies, RUNX2 OE was induced at 2 months of age. Surprisingly, no histopathological signs of cartilage degeneration were observed even 6 months following induction of RUNX2 OE. Using the meniscal/ligamentous injury (MLI), a surgical model of knee joint destabilization and meniscal injury, however, we found that RUNX2 OE accelerates the progression of cartilage degeneration following joint trauma. One month following MLI, the numbers of MMP13-positive and TUNEL-positive chondrocytes were significantly greater in the articular cartilage of the RUNX2 OE joints compared to control joints and 2 months following MLI, histomorphometry and Osteoarthritis Research Society International (OARSI) scoring revealed decreased cartilage area in the RUNX2 OE joints. Collectively, these results suggest that although RUNX2 overexpression alone may not be sufficient to initiate the OA degenerative process, it may predetermine the rate of OA onset and/or progression following traumatic joint injury. © 2019 American Society for Bone and Mineral Research.

Evaluating Patients for Elective Outpatient Foot and Ankle Surgery: Insurance as a Predictor of Patient Outcomes.

Background. Elective surgical procedures necessitate careful patient selection. Insurance level has been associated with postoperative outcomes in trauma patients. This study evaluates the relationship insurance level has with outcomes from elective foot and ankle surgery. Methods. Retrospective chart review was performed on patients who underwent elective surgery at a single center with 1-year follow-up. Patients were classified by insurance: under-/uninsured (Medicaid, Option plans) versus fully insured. Outcomes included narcotic refills, patient-reported outcomes (PROMIS) of pain, function, and mood, and compliance with follow-up visits. Statistical analysis involved mean comparison and multivariate regression modeling, with significance P < .05. Results. Cohort groups included 220 insured and 47 under-/uninsured. Outcomes between the insured and under-/uninsured groups differed significantly in narcotic refills (0.72 vs 1.74 respectively, P < .01), missed appointments (0.13 vs 0.62, P < .01), and PROMIS results (pain 54.5 vs 60.2; function 44.3 vs 39.5; mood 44.6 vs 51.3; P < .01). The change in PROMIS scores from preoperative to 1-year postoperative were different in pain (-7.3 vs -2.5, P = .03) and function (+6.3 vs +1.3, P = .04). Regression results confirm insurance as a significant factor (coefficient 0.27, P < .01). Conclusion. These results establish that under-/uninsured patients have worse pain, patient-reported outcomes, and functional outcomes after elective foot and ankle surgery, which may inform patient selection. Levels of Evidence: Level III: Retrospective cohort study.

Whole Transcriptome Analysis of Renal Intercalated Cells Predicts Lipopolysaccharide Mediated Inhibition of Retinoid X Receptor alpha Function.

The renal collecting duct consists of intercalated cells (ICs) and principal cells (PCs). We have previously demonstrated that collecting ducts have a role in the innate immune defense of the kidney. Transcriptomics is an important tool used to enhance systems-level understanding of cell biology. However, transcriptomics performed on whole kidneys provides limited insight of collecting duct cell gene expression, because these cells comprise a small fraction of total kidney cells. Recently we generated reporter mouse models to enrich collecting duct specific PC and ICs and reported targeted gene expression of anti-microbial peptide genes. Here we report transcriptomics on enriched ICs and PCs and performed a pilot study sequencing four single ICs. We identified 3,645 genes with increased relative expression in ICs compared to non-ICs. In comparison to non-PCs, 2,088 genes had higher relative expression in PCs. IC associated genes included the innate interleukin 1 receptor, type 1 and the antimicrobial peptide(AMP) adrenomedullin. The top predicted canonical pathway for enriched ICs was lipopolysaccharide/Interleukin 1 mediated inhibition of Retinoid X Receptor alpha function and decreased Retinoid X Receptor expression was confirmed to occur 1-hour post experimental murine UTI in ICs but not in non-ICs.

Spring ligament tear decreases static stability of the ankle joint.

BACKGROUND: Spring ligament tear is often found in advanced adult acquired flatfoot deformity and its reconstruction in conjunction with the deltoid ligament has been proposed to restore the tibiotalar and talonavicular joint stability. The aim of the present study is to determine the effect of spring ligament injury and subsequent reconstruction on static joint reactive force using a non-invasive method of measurement. METHODS: Ten fresh-frozen human cadaveric lower legs were disarticulated at the knee joint. Static joint reactive force of the tibiotalar and talonavicular joint were measured at baseline, after spring ligament injury, and after ligament reconstruction. Reconstruction consisted of a forked semitendinosis allograft with dual limbs to reconstruct the tibionavicular and tibiocalcaneal ligaments. FINDINGS: The mean baseline joint reactive force of the tibiotalar and talonavicular joints were 37.2 N + 8.1 N and 13.4 N + 4.2 N, respectively. The spring ligament injury model resulted in a significant 29% decrease in tibiotalar joint reactive force. Reconstruction of the tibionavicular limb resulted in a significant increase in tibiotalar and talonavicular joint reactive force compared to those seen in the injury state. Furthermore, the addition of the tibiocalcaneal limb significantly increased tibiotalar joint reactive force compared to those results obtained from the injury state and the tibionavicular limb alone. INTERPRETATION: This is the first study to demonstrate diminished tibiotalar static joint reactive force in a spring ligament injury model with subsequent joint reactive force restoration using two-limbed reconstruction of the deltoid and spring ligament. LEVEL OF EVIDENCE: Biomechanical Study.