Similar Medium-Term Revision Rates Following Acute Total Hip Arthroplasty Versus Open Reduction and Internal Fixation for Acetabular Fractures in the Elderly.

BACKGROUND: The management of elderly acetabular fractures is complex, with high rates of conversion total hip arthroplasty (THA) after open reduction and internal fixation (ORIF), but potentially higher rates of complications after acute THA. METHODS: The California Office of Statewide Health Planning and Development database was queried between 2010 and 2017 for all patients aged 60 years or older who sustained a closed, isolated acetabular fracture and underwent ORIF, THA, or a combination. Chi-square tests and Student t tests were used to identify demographic differences between groups. Multivariate regression was used to evaluate predictors of 30-day readmission and 90-day complications. Kaplan-Meier (KM) survival analysis and Cox proportional hazards model were used to estimate the revision surgery-free survival (revision-free survival [RFS]), with revision surgery defined as conversion THA, revision ORIF, or revision THA. RESULTS: A total of 2,184 surgically managed acetabular fractures in elderly patients were identified, with 1,637 (75.0%) undergoing ORIF and 547 (25.0%) undergoing THA with or without ORIF. Median follow-up was 295 days (interquartile range, 13 to 1720 days). 99.4% of revisions following ORIF were for conversion arthroplasty. Unadjusted KM analysis showed no difference in RFS between ORIF and THA (log-rank test P = 0.27). RFS for ORIF patients was 95.1%, 85.8%, 78.3%, and 71.4% at 6, 12, 24 and 60 months, respectively. RFS for THA patients was 91.6%, 88.9%, 87.2%, and 78.8% at 6, 12, 24 and 60 months, respectively. Roughly 50% of revisions occurred within the first year postoperatively (49% for ORIF, 52% for THA). In propensity score-matched analysis, there was no difference between RFS on KM analysis ( P = 0.22). CONCLUSIONS: No difference was observed in medium-term RFS between acute THA and ORIF for elderly acetabular fractures in California. Revision surgeries for either conversion or revision THA were relatively common in both groups, with roughly half of all revisions occurring within the first year postoperatively. LEVEL OF EVIDENCE: III.

Postoperative Care and Outcomes in Solid-Organ Transplant Patients Undergoing Lower Extremity Fracture Treatment.

OBJECTIVES: To determine the postoperative outcomes in solid-organ transplant (SOT) patients undergoing operative treatment of lower extremity fractures. DESIGN: Retrospective comparative study. SETTING: Academic Level 1 trauma center. PATIENT SELECTION CRITERIA: Patients who underwent SOT and operative treatment of lower extremity fracture from 2013 to 2021 were identified, excluding pathologic fractures. OUTCOME MEASURES AND COMPARISONS: Postoperative complications, length of stay, time to death, 90-day and 1-year readmission rates, readmission causes, discharge location, and immunosuppressive regiments. RESULTS: Sixty-one patients with an average age of 67 years (range 29-88) were included. The mortality rate was 37.7%. The average follow-up was 15.2 months (range of 2 weeks-10 years). The majority of patients (32.8%) had received a liver transplant, and femoral neck fractures constituted the largest fracture group. The average length of stay was 10 days, with the shortest being 1 day and the longest being 126 days (SD 18). The majority of patients (57.3%) were not discharged home. Only 2 suffered from a postoperative complication requiring another procedure: hardware removal and liner exchange for periprosthetic joint infection, respectively. There was a 27.9% 90-day readmission rate with 2 deaths within that period with the most common being altered mental status (29.4%), genitourinary infections (17.6%), repeat falls (11.8%), and low hemoglobin requiring transfusion (11.8%). The longest average time to death analyzed by transplant type was found among lung transplant patients (1076 days, 62.5% mortality), followed by liver transplant patients (949 days, 35.0% mortality), and then kidney transplant patients (834 days, 38.9% mortality). The shortest time to death was 71 days from index procedure. CONCLUSIONS: Family members of SOT patients undergoing operative treatment of lower extremity fractures should be made aware of the high risk for 90-day readmission postoperatively (27.9%) and overall mortality (12.5%). Providers should be aware of the need for multidisciplinary involvement for inpatient care, monitoring postoperative complications, and facilitating discharge planning. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Reverse total shoulder arthroplasty with proximal bone loss: a biomechanical comparison of partially vs. fully cemented humeral stems.

BACKGROUND: The appropriate amount of cementation at the time of reverse total shoulder arthroplasty with significant proximal bone loss or resection is unknown. Extensive cementation of a humeral prosthesis makes eventual revision arthroplasty more challenging, increasing the risk of periprosthetic fracture. We analyzed the degree of subsidence and torque tolerance of humeral components undergoing standard cementation technique vs. our reduced polymethyl methacrylate (PMMA) protocol. Reduced cementation may provide sufficient biomechanical stability to resist physiologically relevant loads, while still permitting a clinically attainable torque for debonding the prosthesis. METHODS: A total of 12 cadaveric humeri (6 matched pairs) underwent resection of 5 cm of bone distal to the greater tuberosity. Each pair of humeri underwent standard humeral arthroplasty preparation followed by either cementation using a 1.5-cm PMMA sphere at a location 3 cm inferior to the porous coating or standard full stem cementation. A 6-degree-of-freedom robot was used to perform all testing. Each humeral sample underwent 200 cycles of abduction, adduction, and forward elevation while being subjected to a physiologic compression force. Next, the samples were fixed in place and subjected to an increasing torque until implant-cement separation or failure occurred. Paired t tests were used to compare mean implant subsidence vs. a predetermined 5-mm threshold, as well as removal torque in matched samples. RESULTS: Fully and partially cemented implants subsided 0.49 mm (95% CI 0.23-0.76 mm) and 1.85 mm (95% CI 0.41-3.29 mm), respectively, which were significantly less than the predetermined 5-mm threshold (P < .001 and P < .01, respectively). Removal torque between fully cemented stems was 45.22 Nm (95% CI 21.86-68.57 Nm), vs. 9.26 Nm (95% CI 2.59-15.93 Nm) for partially cemented samples (P = .021). Every fully cemented humerus fractured during implant removal vs. only 1 in the reduced-cementation group. The mean donor age in our study was 76 years (range, 65-80 years). Only 1 matched pair of humeri belonged to a female donor with comorbid osteoporosis. The fractured humerus in the partially cemented group belonged to that donor. CONCLUSION: Partially and fully cemented humeral prostheses had subsidence that was significantly less than 5 mm. Partially cemented stems required less removal torque for debonding of the component from the cement mantle. In all cases, removal of fully cemented stems resulted in humeral fracture. Reduced cementation of humeral prostheses may provide both sufficient biomechanical stability and ease of future component removal.

Modifiable and non-modifiable risk factors for failure of non-operative treatment of pediatric forearm fractures: Where can we do better?

Introduction: Distal third forearm fractures are common fractures in children. While outcomes are generally excellent, some patients fail initial non-operative management and require intervention. The purpose of this study is to identify independent risk factors associated with failure of closed reduction. Methods: We conducted a retrospective review of distal third forearm fractures in children treated with closed reduction and casting. Patients were divided into two cohorts-those who were successfully closed reduced and those who failed initial non-operative management. Demographic characteristics, cast type, cast index, radiographic fracture, soft tissue characteristics, and quality of reduction were analyzed between groups. Results: A total of 207 children treated for distal third forearm fractures were included for analysis. A total of 190 (91.8%) children maintained their reduction while 17 (8.2%) failed initial non-operative management. Modifiable risk factors associated with loss of reduction on univariate analysis included the use of a long arm cast (p = 0.003), increased post-reduction displacement (p = 0.02), and increased post-reduction angular deformity (p = 0.01). Non-modifiable risk factors included increased body mass index (p = 0.02), increased presenting fracture displacement (p = 0.002), and increased width of the soft tissue envelope at the fracture site (p = 0.0001). The use of long arm casts (13% vs 2%, odds ratio = 6.44) and soft tissue width (60.6 vs 50.4 mm, odds ratio = 1.1) remained significant risk factors for loss of reduction after multivariate analysis. Conclusion: Both larger soft tissue envelope at the site of the fracture and long arm cast immobilization are independently associated with an increased risk of failing initial closed reduction in distal third forearm fractures in the pediatric population. Level of evidence: level III Case Control Study.

Insurance-Based Disparities in Congenital Cardiac Operations in the Era of the Affordable Care Act.

A body of literature has previously highlighted the impact of health insurance on observed disparities in congenital cardiac operations. With aims of improving access to healthcare for all patients, the Affordable Care Act (ACA) expanded Medicaid coverage to nearly all eligible children in 2010. Therefore, the present population-based study aimed to examine the association of Medicaid coverage with clinical and financial outcomes in the era the ACA. Records for pediatric patients (≤ 18 years) who underwent congenital cardiac operations were abstracted from the 2010-2018 Nationwide Readmissions Database. Operations were stratified using the Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) Category. Multivariable regression models were developed to evaluate the association of insurance status on index mortality, 30-day readmissions, care fragmentation, and cumulative costs. Of an estimated 132,745 hospitalizations for congenital cardiac surgery from 2010 to 2018, 74,925 (56.4%) were insured by Medicaid. The proportion of Medicaid patients increased from 57.6 to 60.8% during the study period. On adjusted analysis, patients with Medicaid insurance were at an increased odds of mortality (1.35, 95%CI: 1.13-1.60) and 30-day unplanned readmission (1.12, 95%CI: 1.01-1.25), experienced longer lengths of stay (+ 6.5 days, 95%CI 3.7-9.3), and exhibited higher cumulative hospitalization costs (+ $21,600, 95%CI: $11,500-31,700). The total hospitalization cost-burden for patients with Medicaid and private insurance were $12.6 billion and $8.06 billion, respectively. Medicaid patients exhibited increased mortality, readmissions, care fragmentation, and costs compared to those with private insurance. Our results of outcome variation by insurance status indicate the necessity of policy changes to attempt to approach equality in surgical out comes for this high-risk cohort. Baseline characteristics, trends, and outcomes by insurance status over the ACA rollout period 2010-2018.

Molecular signatures of retinal ganglion cells revealed through single cell profiling.

Retinal ganglion cells can be classified into more than 40 distinct subtypes, whether by functional classification or transcriptomics. The examination of these subtypes in relation to their physiology, projection patterns, and circuitry would be greatly facilitated through the identification of specific molecular identifiers for the generation of transgenic mice. Advances in single cell transcriptomic profiling have enabled the identification of molecular signatures for cellular subtypes that are only rarely found. Therefore, we used single cell profiling combined with hierarchical clustering and correlate analyses to identify genes expressed in distinct populations of Parvalbumin-expressing cells and functionally classified RGCs. RGCs were manually isolated based either upon fluorescence or physiological distinction through cell-attached recordings. Microarray hybridization and RNA-Sequencing were employed for the characterization of transcriptomes and in situ hybridization was utilized to further characterize gene candidate expression. Gene candidates were identified based upon cluster correlation, as well as expression specificity within physiologically distinct classes of RGCs. Further, we identified Prph, Ctxn3, and Prkcq as potential candidates for ipRGC classification in the murine retina. The use of these genes, or one of the other newly identified subset markers, for the generation of a transgenic mouse would enable future studies of RGC-subtype specific function, wiring, and projection.