Hexokinase 1 cellular localization regulates the metabolic fate of glucose.

The product of hexokinase (HK) enzymes, glucose-6-phosphate, can be metabolized through glycolysis or directed to alternative metabolic routes, such as the pentose phosphate pathway (PPP) to generate anabolic intermediates. HK1 contains an N-terminal mitochondrial binding domain (MBD), but its physiologic significance remains unclear. To elucidate the effect of HK1 mitochondrial dissociation on cellular metabolism, we generated mice lacking the HK1 MBD (ΔE1HK1). These mice produced a hyper-inflammatory response when challenged with lipopolysaccharide. Additionally, there was decreased glucose flux below the level of GAPDH and increased upstream flux through the PPP. The glycolytic block below GAPDH is mediated by the binding of cytosolic HK1 with S100A8/A9, resulting in GAPDH nitrosylation through iNOS. Additionally, human and mouse macrophages from conditions of low-grade inflammation, such as aging and diabetes, displayed increased cytosolic HK1 and reduced GAPDH activity. Our data indicate that HK1 mitochondrial binding alters glucose metabolism through regulation of GAPDH.

Adolescent Idiopathic Scoliosis: Increased Body Mass Associated with Decreased Bracing Outcomes.

Bracing reduces the need for surgical intervention in patients with adolescent idiopathic scoliosis (AIS). However, bracing outcomes with variable body mass index (BMI) are understudied. The authors sought to determine the association of BMI with bracing outcomes. The authors performed a retrospective cohort study of 104 patients presenting with AIS. Initial Risser score, hours of bracing per day, BMI percentile, and curve magnitude pre- and postbracing were collected. There was no detectable difference between years of brace wear or primary curve magnitude at time of presentation between both groups. Overall, 29% (25/87) of underweight/normal weight patients and 59% (10/17) of overweight/obese patients had curves ≥ 45 degrees at the end of bracing (p = 0.016). Odds of having a curve ≥ 45 degrees after bracing were 3.5 (95% confidence interval: 1.2 to 10.3, p = 0.021) times higher for overweight/obese patients compared with underweight/normal weight patients. Increased overlying adipose tissue may reduce the corrective forces required to straighten the spine. (Journal of Surgical Orthopaedic Advances 33(1):029-032, 2024).

Compression Screw Fixation for Pediatric Olecranon Fractures.

BACKGROUND: Pediatric olecranon fractures can be treated with several methods of fixation. Though postoperative outcomes of various fixation techniques, including cannulated intramedullary screws, have been described in adults, functional and radiographic outcomes of screw fixation in pediatric patients are unclear. In this study, we assessed clinical, radiographic, functional, and patient-reported outcomes of pediatric olecranon fractures treated with compression screw fixation. METHODS: We retrospectively identified 37 patients aged 16 years or younger with a total of 40 olecranon fractures treated with screw fixation at our level-1 trauma center between April 2005 and April 2022. From medical records, we extracted data on demographic characteristics, time to radiographic union, range of elbow motion at final follow-up, and complications during the follow-up period. Patient-reported outcomes were evaluated using the Quick Disabilities of the Arm, Shoulder, and Hand and Patient-Reported Outcomes Measurement Information System Pediatric Upper Extremity Short Form 8a measures. RESULTS: There were no malunions or nonunions at the final mean follow-up of 140 days (range, 26 to 614 d). Four patients had implant failure (11%), of whom 3 experienced fracture union with no loss of fixation or need for revision surgery. One patient underwent a revision for fracture malreduction. Screw prominence was documented in 1 patient. Instrumentation was removed at our institution for 33 of 40 fractures. Mean time to radiographic union was 53 days (range, 20 to 168 d). Postoperative range of motion at the most recent follow-up visit showed a mean extension deficit of 6 degrees (range, 0-30 degrees) and mean flexion of 134 degrees (range, 60-150 degrees). At the final follow-up, the mean (±SD) Quick Disabilities of the Arm, Shoulder, and Hand score was 4.2±8.0, and the mean Patient-Reported Outcomes Measurement Information System score was 37±1.5, indicating good function and patient satisfaction. CONCLUSIONS: All 37 patients in our series had excellent radiographic, functional, and patient-reported outcomes after screw fixation. We observed no cases of nonunion or malunion, growth disturbance, or refracture. These results suggest that screw fixation is a safe and effective option for pediatric olecranon fractures. LEVEL OF EVIDENCE: Level IV, case series.

Consensus-Based Best Practice Guidelines for the Management of Spinal Deformity and Associated Tumors in Pediatric Neurofibromatosis Type 1: Screening and Surveillance, Surgical Intervention, and Medical Therapy.

BACKGROUND: Spinal conditions, such as scoliosis and spinal tumors, are prevalent in neurofibromatosis type 1 (NF1). Despite the recognized importance of their early detection and treatment, there remain knowledge gaps in how to approach these manifestations. The purpose of this study was to utilize the experience of a multidisciplinary committee of experts to establish consensus-based best practice guidelines (BPGs) for spinal screening and surveillance, surgical intervention, and medical therapy in pediatric patients with NF1. METHODS: Using the results of a prior systematic review, 10 key questions that required further assessment were first identified. A committee of 20 experts across medical specialties was then chosen based on their clinical experience with spinal deformity and tumors in NF1. These were 9 orthopaedic surgeons, 4 neuro-oncologists/oncologists, 3 neurosurgeons, 2 neurologists, 1 pulmonologist, and 1 clinical geneticist. An initial online survey on current practices and opinions was conducted, followed by 2 additional surveys via a formal consensus-based modified Delphi method. The final survey involved voting on agreement or disagreement with 35 recommendations. Items reaching consensus (≥70% agreement or disagreement) were included in the final BPGs. RESULTS: Consensus was reached for 30 total recommendations on the management of spinal deformity and tumors in NF1. These were 11 recommendations on screening and surveillance, 16 on surgical intervention, and 3 on medical therapy. Five recommendations did not achieve consensus and were excluded from the BPGs. CONCLUSION: We present a set of consensus-based BPGs comprised of 30 recommendations for spinal screening and surveillance, surgical intervention, and medical therapy in pediatric NF1.

Rate of Tibiotalocalcaneal (TTC) Fusion Using the Surgical Implant Generation Network (SIGN) Intramedullary Nail in Developing Countries.

Outcomes of the Surgical Implant Generation Network (SIGN) nail have been reported for femur and tibial fractures, but its use in tibiotalocalcaneal arthrodesis (TTCA) is not well studied. Radiographic and clinical outcomes of TTCA using the SIGN database in patients with > 6 months of radiographic follow up were analyzed. Rates of tibiotalar (TT) fusion and subtalar (ST) fusion at final follow up were assessed by two independent reviewers. Of the 62 patients identified, use of the SIGN nail for TCCA resulted in 53% rate of fusion in the TT joint and 20% in the ST joint. Thirty-seven patients (60%) demonstrated painless weight bearing at final follow up. There were no differences in incidence of painless weight bearing between consensus fused and not fused cohorts for TT and ST joints (p > 0.05). There were five implant failures, no cases of infection, and seven cases of reoperation. (Journal of Surgical Orthopaedic Advances 32(3):187-192, 2023).

Sacral-Alar-Iliac (SAI) Fixation in Children With Spine Deformity: Minimum 10-Year Follow-Up.

INTRODUCTION: Sacral-alar-iliac (SAI) screws are utilized to achieve pelvic fixation in spine deformity patients. The primary purpose of this study is to investigate the long-term outcomes of pediatric patients with scoliosis treated with posterior spinal fusion and SAI fixation at 10-year clinical and radiographic follow-up. METHODS: We reviewed the clinical and radiographic records of patients aged 18 years or below treated for scoliosis with posterior spinal fusion using SAI fixation. Pelvic obliquity and the major coronal curve were determined at the preoperative visit and 6-week, 1-year, 5-year, and 10-year postoperative visits. SAI screw-specific data collected included screw dimensions, rate of screw revision, pain at the SAI screw sites, presence of lucency >2 mm around the screw, screw loosening or breaking, and deep surgical site infections. RESULTS: Ninety-seven of 151 patients (75%) were included. The average age at index surgery was 13.5±3.1 years, and the most common diagnosis was cerebral palsy (67%). The mean duration of follow-up was 11±3 years. The mean pelvic obliquity measured 20±8.0 degrees preoperatively, and 8.7±4.0 degrees at the 10-year follow-up. There were no significant difference in pelvic obliquity when comparing the 10-year follow-up visit with the 6-week postoperative follow-up. Average screw dimensions were 8.4×68.8 mm. By the 10-year follow-up, 4 patients (4%) had at least 1 SAI screw-related complication. Of these patients, 2 (2%) had pain at 1 SAI screw, 4 (4%) had lucency around the screw, and 3 (3%) had broken or loose screws. Two (2%) required SAI screw revision because of late deep wound infection, and underwent exchange with a longer screw. There were no intrapelvic protrusions, vascular, or neurological complications. CONCLUSIONS: SAI screws are a safe and effective method for pelvic fixation in children with spinal deformity. The outcomes at ≥10 years are satisfactory, with low rates of long-term complications and excellent postoperative correction and subsequent maintenance of coronal curvature and pelvic obliquity over time. LEVEL OF EVIDENCE: Level IV.

Pelvic Osteotomy in Patients With Previous Sacral-Alar-Iliac (SAI) Fixation.

INTRODUCTION: Patients with neuromuscular disease are at high risk for developing hip dysplasia and scoliosis. The purpose of this study was to investigate the technical challenges and outcomes of pelvic osteotomy in patients with prior sacral-alar-iliac (SAI) fixation. METHODS: We reviewed clinical and radiographic records of patients aged 18 years and below who underwent pelvic osteotomy after SAI fixation. We recorded technical challenges during the osteotomy, time from SAI fixation to osteotomy, type of osteotomy, migration index, and distance from the SAI screw to the acetabulum. A 2-sample Wilcoxon rank-sum test was used to assess the data. RESULTS: Nineteen patients were included. Technical challenges were defined as having greater intraoperative fluoroscopy times and noted difficult osteotomy in the operative report. The mean time from SAI fixation to pelvic osteotomy was 2.2±1.5 years. For all 12 Chiari osteotomies, the ilium could not be laterally displaced; however, medial displacement of the distal segment of the osteotomy allowed adequate coverage. All 7 Dega osteotomies were performed by cutting the cortex at the tip of the SAI screw. The screw improved proximal leverage and provided a strong buttress for bone graft. The mean migration index before pelvic osteotomy was 59±19%, and at most recent follow-up was 13±4%. Twelve patients, who had a noted complicated osteotomy, had SAI screws that were ≤1.87 cm ( P <0.01) from the acetabulum and significantly increased intraoperative fluoroscopy time (1.76 vs. 1.18 min, P <0.01). CONCLUSIONS: The presence of SAI screws may cause iliac osteotomies to be technically challenging if the tip of the SAI screw is ≤1.87 cm to the acetabulum. When initially implanting SAI screws in neuromuscular patients, surgeons should attempt to place screw tips ∼2 cm from the acetabulum in the event these patients require subsequent pelvic osteotomy. LEVEL OF EVIDENCE: Level IV.

Minimizing the Risk of Vascular Injury: Anatomy of the Popliteal Artery in the Pediatric Knee.

BACKGROUND: Displaced pediatric tibial tubercle fractures are commonly stabilized with screws directed posteriorly toward neurovascular structures. Here, we (1) characterize the variation of the popliteal artery among pediatric patients; and (2) recommend a safe screw trajectory for fixation of tibial tubercle fractures. METHODS: We retrospectively identified 42 patients (42 knees; 29 female) aged 12-17 years with lower-extremity magnetic resonance imaging (MRI) at a tertiary academic center. The mean patient age was 14.5 (range: 12-17) years, and the mean body mass index value was 19.1 (range: 14.9-25.1). We included patients with open physes or visible physeal scars and excluded those with prior instrumentation or lower-extremity injury. Using sagittal MRI, we measured the distances from 5 levels each on the anterior and posterior tibial cortex to the popliteal artery (level 1, midpoint of proximal tibial epiphysis; level 2, the proximal extent of the tubercle; level 3, tubercle prominence; level 4, 2 cm distal to the proximal extent of the tubercle; level 5, 4 cm distal to the proximal extent of the tubercle). Using coronal MRI, we measured the width of the tibia at each level and the distance from the lateral-most and medial-most cortex to the artery. RESULTS: The popliteal artery was laterally positioned in all knees. The mean distance between the artery and lateral-most aspect of the tibia at each level ranged from 1.9 to 2.4 cm, and from 2.3 to 3.9 cm from the medial-most aspect of the tibia. The mean distance that a screw can advance before vascular injury was 5.1 cm at level 1. The shortest mean distance to the popliteal artery was 1.7 cm, at level 5. There is minimal distance between the posterior tibial cortex and the artery at all levels. CONCLUSIONS: Understanding the position of the popliteal artery in pediatric patients can help when stabilizing tibial tubercle fractures. Because the artery is close to the posterior cortex, a drill exiting in line with the popliteal artery risks vascular injury. Therefore, we recommend that screws exit within the medial 60% of the tibia. LEVEL OF EVIDENCE: IV.

Connective Tissue Disease Patients Maintain Greater Distraction During Growth Friendly Surgery.

STUDY DESIGN: Multicenter retrospective study. BACKGROUND: Recent studies have demonstrated diminishing returns in patients with early onset scoliosis (EOS) undergoing repeated lengthening of growing rods. Little is known about whether this same phenomenon occurs in patients with lax connective tissue disease (CTD). The primary purpose of this study is to investigate whether EOS patients with connective tissue laxity disorders have diminishing returns during growth friendly surgery. METHODS: CTD EOS patients below 10 years old, underwent growth friendly spine surgery with distal anchors and at least 1 proximal spine anchor, and had minimum follow-up of 5 years were included in this study. Coronal T1-S1 height at preindex surgery, postindex, and every available lengthening was assessed. Mean coronal height change during early set distractions and late set distractions were calculated for the cohort. To account for varying distraction intervals, we normalized the distractions by the time interval. The outcome parameter was T1-S1 height gain, mm/year. RESULTS: Twenty-one CTD patients were included in this study. Total coronal height (T1-S1) was 26.7MHCcm before index, 32.2 cm at D1-D3, 34.7 cm at D4-D6, and 36.7 cm at D7-L10. There were no significant differences in coronal height gains between early and late distractions (P=0.70). Moreover, when normalized for time, there was no significant difference in net gain per year at different lengthening time points for the CTD group, P=0.59. CONCLUSION: There is no evidence of diminishing returns in coronal T1-S1 height gain in patients with EOS in the setting of CTD. LEVEL OF EVIDENCE: Level III.

Interlocking Fixation in Fassier-Duval Rods: Performance and Success Factors.

INTRODUCTION: Pediatric patients with osteogenesis imperfecta (OI) can be treated with intramedullary Fassier-Duval rod (FDR) systems for limb deformity or recurrent fractures. Single-interlocking pins can improve epiphyseal fixation, but there is a paucity of literature examining incidence of rod migration or pin backout long-term. The purpose of this study is to quantify rates of rod migration and pin backout in OI patients treated with single-interlocking FDRs. METHODS: A retrospective chart review was performed on pediatric patients treated at a tertiary care center across a 15-year period. Inclusion criteria to select patients was: (1) Pediatric patients (below 18 y of age); (2) Patients with confirmed OI; and (3) Patients with lower extremity fractures or deformity treated with FDRs with distal interlocking pins. Age at time of surgery, rates of obturator migration and pin backout and prominence were collected. We recorded if pin tips were bent by the surgeon during the procedure. Bivariate statistics were used to analyze risk factors for pin backout and prominence. RESULTS: Twenty-four single-interlocking pin FDRs (21 tibia, 3 femur) were identified. The mean age at index surgery was 5.7±3.4 years, with the mean follow-up time of 7.2±4.7 years. Fourteen (58%) rods underwent revision surgery. Obturator proximal migration was observed in 3/24 rods (13%). No cases of obturator distal migration were observed (0/24, 0%). Mean proximal obturator migration was 2.16±1.8 cm. Revision for pin backout was observed in 10 (42%) rods and pin prominence in 11 (46%) extremities. Bending interlocking pins on at least 1 end was associated with decreased pin backout (P=0.01) and prominence (P=0.04). CONCLUSIONS: Even with distal interlocking pins, the obturator of FDRs can still migrate over time. Pin backout is a common indication for revision surgery. Bending interlocking pins can decrease rates of pin backout and prominence. LEVEL OF EVIDENCE: Level III.

Preference Signaling Survey of Program Directors-After the Match.

INTRODUCTION: The 2022 to 2023 orthopaedic residency cycle implemented a preference signaling program (PSP), allowing applicants to send "signals" to up to 30 programs to demonstrate their genuine interest. With the conclusion of the 2022 to 2023 cycle, the primary purpose of this study was to analyze program director (PD) perceptions of the PSP after the match cycle and provide a retrospective evaluation of the effects of the PSP on the orthopaedic resident selection process. METHODS: A 21-question survey was distributed to 98 PDs (32.7% response rate). Contact information was obtained from a national database. RESULTS: Most respondents (96.9%) participated in the American Orthopaedic Association's PSP. The majority (93.7%) view preference signaling as a positive change. Most PDs (56.2%) reported a decreased number in applications received compared with previous years. Receiving a preference signal was ranked among the most important factors in resident selection, and most PDs agreed that preference signaling should be used to screen applicants (84.4%) and differentiate similar applicants (96.8%). Moreover, 65.6% of PDs indicated that they would not rank or invite applicants to interview without a signal or completion of a formal away rotation. PDs report that in the 2022 to 2023 cycle, 98.5% of applicants who matched at their program had sent a preference signal. DISCUSSION: Preference signaling was one of the most important factors assessed during its inaugural application cycle and is anticipated to remain a key tool for screening and differentiating candidates. Applicants should strategically select signal recipients to enhance their success in the match.

Professional Society Opportunities and Involvement for Early-Career Orthopaedic Surgeons.

Professional societies can provide orthopaedic surgeons opportunities to build strong fellowship among colleagues within a specialty, to gain leadership positions and responsibilities, and to contribute to the latest research and practice management guidelines. However, early-career surgeons often receive little to no guidance about how membership can benefit them in the long term. The primary purpose of this review article was to provide an overview of orthopaedic professional societies, why early-career orthopaedic surgeons should consider membership, and how they can get involved. Topics discussed in this article include the missions of various societies, value in career advancement both in academic and private practice settings, benefits to patient care, and tips for budding surgeons on how to rise up the ranks within a given professional society. We also provide a comprehensive list of leadership development, fellowship, mentorship, and research opportunities that are designed for orthopaedic surgeons within their first 10 years of practice.

Social Media Presence Is Associated With Diversity and Application Volume for Orthopedic Surgery Residency Programs.

The purpose of this study was to assess the association between social media presence (Twitter and Instagram), diversity in orthopedic surgery residency programs, and the number of applications received by a program. Data from Twitter and Instagram for 179 orthopedic residency programs accredited by the Accreditation Council for Graduate Medical Education were collected, including the presence of a social media account, date of first post, number of posts, and number of followers. Residency program data were collected from the Association of American Medical Colleges Residency Explorer Tool and included percentage of Whiteresidents, percentage of male residents, residency ranking, and number of applications submitted during the 2019 application cycle. Bivariate and multivariable analyses were performed with adjustment for program ranking. Of 179 residency programs, 34.6% (n=62) had Twitter, and 16.7% (n=30) had Instagram. Overall, 39.7% (n=71) had a social media presence, defined as having at least one of the two forms of social media. Programs with social media presences had higher average rankings (48.1 vs 99.6 rank, P<.001). After adjusting for program ranking, social media presence was associated with increased applications during the 2019 application cycle (odds ratio [OR]=2.76, P=.010). Social media presence was associated with increased odds of gender diversity (OR=3.07, P=.047) and racial diversity (OR=2.21, P=.041). Individually, Twitter presence was associated with increased odds of gender (OR=4.81, P=.018) and racial diversity (OR=4.00, P=.021), but Instagram was not (P>.05). Social media presence is associated with more residency program applications and increased resident diversity. Social media can be used to highlight inclusivity measures and related opportunities. [Orthopedics. 2023;46(1):47-53.].

Racial Disparities in Spine Surgery: A Systematic Review.

STUDY DESIGN: Systematic Review. OBJECTIVES: To synthesize previous studies evaluating racial disparities in spine surgery. METHODS: We queried PubMed, Embase, Cochrane Library, and Web of Science for literature on racial disparities in spine surgery. Our review was constructed in accordance with Preferred Reporting Items and Meta-analyses guidelines and protocol. The main outcome measures were the occurrence of racial disparities in postoperative outcomes, mortality, surgical management, readmissions, and length of stay. RESULTS: A total of 1753 publications were assessed. Twenty-two articles met inclusion criteria. Seventeen studies compared Whites (Ws) and African Americans (AAs) groups; 14 studies reported adverse outcomes for AAs. When compared with Ws, AA patients had higher odds of postoperative complications including mortality, cerebrospinal fluid leak, nervous system complications, bleeding, infection, in-hospital complications, adverse discharge disposition, and delay in diagnosis. Further, AAs were found to have increased odds of readmission and longer length of stay. Finally, AAs were found to have higher odds of nonoperative treatment for spinal cord injury, were more likely to undergo posterior approach in the treatment of cervical spondylotic myelopathy, and were less likely to receive cervical disk arthroplasty compared with Ws for similar indications. CONCLUSIONS: This systematic review of spine literature found that when compared with W patients, AA patients had worse health outcomes. Further investigation of root causes of these racial disparities in spine surgery is warranted.

Sacral-Alar-Iliac (SAI) Fixation in Patients With Previous Pelvic Osteotomy.

STUDY DESIGN: This was a retrospective study. OBJECTIVE: The purpose of this study was to investigate the technical challenges and outcomes of sacral-alar-iliac (SAI) fixation for scoliosis in patients who had previously undergone a pelvic osteotomy for hip dysplasia. SUMMARY OF BACKGROUND DATA: Patients with neuromuscular disease are at high risk for developing hip dislocation and scoliosis. Surgical correction of one may affect the other. METHODS: We reviewed the records of patients aged 18 years and below who underwent spinal fusion using SAI screws after having undergone a pelvic osteotomy, with ≥2-year follow-up. We recorded the SAI screw dimensions, time from osteotomy to SAI fixation, type of osteotomy, and any complications performing SAI fixation due to the pelvic osteotomy. Bivariate statistics were used to analyze the data with statistical significance defined as P -value <0.05. RESULTS: Thirty-two patients were included. The average age was 10.3±3.2 years at pelvic osteotomy and 13.5±3.4 years at SAI fixation. Most patients had cerebral palsy (87.5%) and a unilateral Dega osteotomy (78.1%). Average screw dimensions were significantly shorter on the side of the osteotomy (66 vs. 72 mm, P <0.05). SAI screw placement was technically challenging in 8 patients (25%), due to pelvic distortion from the pelvic osteotomy. The use of a curved awl helped to find the intracortical channel. No patients had complications due to the SAI screw, and there were no significant differences in pelvic obliquity and major coronal curve correction. Two patients (6.3%) had screw lucency >2 mm around the SAI screw on the side of the pelvic osteotomy but no clinical symptoms. CONCLUSIONS: SAI fixation in patients with previous pelvic osteotomy is technically challenging due to pelvic morphology and prior implants. Often, a shorter SAI screw is required on the side of the osteotomy. However, outcomes in this patient population are satisfactory, with no significant complications at a 2-year follow-up. LEVEL OF EVIDENCE: Level IV.

Can magnetically controlled growing rods be successfully salvaged after deep surgical site infection?

PURPOSE: The purpose is to compare the rate of recurrent deep wound infection in patients who retained MCGRs versus those who underwent implant removal and exchange following index deep wound infection. METHODS: Using a multicenter registry, we identified patients with EOS who underwent surgical correction with MCGR. We defined deep SSI as any infection that required subsequent I&D and antibiotic therapy. Recurrent infection was defined as any additional deep SSI following treatment of index deep infection. We considered MCGR to be salvaged if implant exchange or removal was not performed for at least 1 year following date of infection. Bivariate statistical analyses were performed. RESULTS: 992 EOS patients were identified, of whom 33 (3.3%) developed deep SSI. The mean time between initial surgery and first deep SSI was 13.1 months (Interquartile range [IQR]: 1 to 25 months. Infection rates by EOS diagnosis were as follows: 13/354 patients (3.6%) had neuromuscular scoliosis (NMS), 9/225 (4.0%) syndromic, 6/248 (2.4%) idiopathic, 3/135 congenital (2.2%), and 2/30 (6.6%) unknown etiology. MCGR was salvaged in 69% of NMS patients, 77% of syndromic patients, 100% of congenital patients, and 83% of idiopathic patients (83%). There were only four recurrent infections (2/13 NMS, 2/9 syndromic) and no differences in rates of recurrent infection between salvaged or replaced/exchanged MCGR. (p = 0.97). CONCLUSION: Deep wound infection occurred in 3% of MCGR patients at a mean of 13.1 months. There were no significant differences in rates of recurrent infection between salvaged implants and those removed or exchanged.

Preference Signaling for Orthopaedic Surgery Applicants: A Survey of Residency Program Directors.

INTRODUCTION: On March 30, 2022, the American Orthopaedic Association's Council of Orthopaedic Residency Directors announced its endorsement for a preference signaling program (PSP) for the 2022 to 2023 orthopaedic residency application cycle. The purpose of our study was to assess orthopaedic surgery residency program director (PD) perceptions of the PSP and analyze potential effects of the PSP on the residency application process. METHODS: A 19-question survey was distributed to 98 PDs (40.8% response rate). Contact information was obtained from a national database. RESULTS: Most programs plan to participate in the PSP (87.5%). Preference signaling is highly regarded for residency selection, with PDs ranking its relative importance just below away rotation performance and personal knowledge of the applicant. Most PDs agreed that applicants will have increased chances of receiving interviews at programs they send a preference signal (65%). Most PDs also do not think that the PSP will help improve diversity (42.5%) and combat the overapplication phenomenon (67.5%). A majority think that an application cap limiting the total number of applications submitted should be initiated in future application cycles (85%). CONCLUSION: Preference signaling will be one of the most important factors considered during orthopaedic residency selection. A signal will likely improve applicants' chance of receiving an interview. Thus, students should be selective about where they send their preference signals and invest time in creating strong, personal connections with a few, select programs to increase their success in the orthopaedic residency match.

Preoperative Hyponatremia Is an Independent Risk Factor for Prolonged Hospital Stay After Anterior Cervical Discectomy and Fusion.

OBJECTIVE: To determine the association of preoperative hyponatremia with short-term postoperative complications and health care utilization (length of stay, readmissions) after anterior cervical fusion and discectomy (ACDF). METHODS: Patients who underwent ACDF were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patients who had revision surgery, trauma, vertebral malignancy, or infection were excluded. Eunatremia was defined as sodium (Na) level between 135 and 145 mEq/L, whereas hyponatremia was defined as Na < 135 mEq/L. Preoperatively, patients with hyponatremia were matched 1:1 with patients with eunatremia using propensity score matching based on age, sex, American Society of Anesthesiologists score, and baseline comorbidities. Minor adverse events included superficial infection, dehiscence, urinary tract infection, pneumonia, and renal insufficiency or failure. Serious adverse events included deep wound infection, reintubation, pulmonary embolism, cerebrovascular accident, cardiac arrest, deep vein thrombosis, sepsis, return to operating room, and death within 30 days. Complications were analyzed using bivariate and logistic analysis with significance set at P < 0.05. RESULTS: Of the 9094 patients undergoing ACDF, 3.64% (n = 331) were preoperatively hyponatremic. Preoperative hyponatremia was an independent risk factor for postoperative pneumonia after ACDF (odds ratio [OR], 4.47; P = 0.020) and extended length of hospital stay >1 SD above the mean (OR, 1.71; P = 0.042). Preoperative hyponatremia was an independent risk factor for having a serious adverse event (OR, 2.40; P = 0.005) and any adverse event (OR, 2.44; P = 0.009). CONCLUSIONS: Preoperative hyponatremia is an independent risk factor for pneumonia and prolonged length of stay after ACDF.

Regional or Neuraxial Anesthesia May Help Mitigate the Effects of Bone Cement Implantation Syndrome in Patients Undergoing Cemented Hip and Knee Arthroplasty for Oncologic Indications.

INTRODUCTION: Bone cement implantation syndrome (BCIS) occurs during and after cementation of implants and is associated with hypotension, hypoxia, and cardiovascular collapse. In this study, we aimed to identify risk factors and potential mitigating factors of BCIS in the oncologic adult cohort undergoing cemented arthroplasty. METHODS: We retrospectively reviewed oncologic patients aged 18 years or older who underwent cemented arthroplasty of either the hip or knee from 2015 to 2020. All implants were stemmed. We classified BCIS into three separate categories: (1) grade 1: intraoperative moderate hypoxia (<94%) or drop in systolic blood pressure >20%; (2) grade 2: intraoperative severe hypoxia or drop in systolic blood pressure >40%; and (3) grade 3: cardiovascular collapse requiring cardiopulmonary resuscitation. Demographics, primary malignancy diagnosis, intraoperative factors including cement timing, development of BCIS, 30-day postoperative outcomes, and mortality up to 2 years postoperatively were evaluated. Bivariate analyses and multivariate logistic regression were performed. RESULTS: Sixty-seven patients met inclusion criteria. Of these, 31 patients (46%) developed BCIS. No difference was found in age (65.5 versus 60.9 years; P = 0.15) or body mass index (28.8 kg/m2 versus 29.3 kg/m2; P = 0.76), comorbidities, intraoperative factors, or postoperative surgical outcomes between those who developed BCIS and those who did not (all; P > 0.05). An association with the type of anesthesia administered and development of BCIS in patients receiving general anesthesia alone (17/24 patients, 71%), neuraxial and general (4/15 patients, 27%), and regional and general anesthesia (10/28 patients 36%, P = 0.01) was found. Compared With neuraxial and regional anesthesia, general anesthesia alone had 5.8 (P = 0.007) and 4.5 times (P = 0.006) greater odds of developing BCIS, respectively. No differences were noted in rates of BCIS between regional and neuraxial anesthesia (P = 0.81). DISCUSSION: Addition of regional or neuraxial anesthesia may be protective in reducing development of BCIS in the orthopaedic oncologic cohort undergoing hip and knee arthroplasty. LEVEL OF EVIDENCE: III.

Spine Surgery and Preoperative Hemoglobin, Hematocrit, and Hemoglobin A1c: A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVES: Synthesize previous studies evaluating clinical utility of preoperative Hb/Hct and HbA1c in patients undergoing common spinal procedures: anterior cervical discectomy and fusion (ACDF), posterior cervical fusion (PCF), posterior lumbar fusion (PLF), and lumbar decompression (LD). METHODS: We queried PubMed, Embase, Cochrane Library, and Web of Science for literature on preoperative Hb/Hct and HbA1c and post-operative outcomes in adult patients undergoing ACDF, PCF, PLF, or LD surgeries. RESULTS: Total of 4,307 publications were assessed. Twenty-one articles met inclusion criteria. PCF AND ACDF: Decreased preoperative Hb/Hct were significant predictors of increased postoperative morbidity, including return to operating room, pulmonary complications, transfusions, and increased length of stay (LOS). For increased HbA1c, there was significant increase in risk of postoperative infection and cost of hospital stay. PLF: Decreased Hb/Hct was reported to be associated with increased risk of postoperative cardiac events, blood transfusion, and increased LOS. Elevated HbA1c was associated with increased risk of infection as well as higher visual analogue scores (VAS) and Oswestry disability index (ODI) scores. LD: LOS and total episode of care cost were increased in patients with preoperative HbA1c elevation. CONCLUSION: In adult patients undergoing spine surgery, preoperative Hb/Hct are clinically useful predictors for postoperative complications, transfusion rates, and LOS, and HbA1c is predictive for postoperative infection and functional outcomes. Using Hct values <35-38% and HbA1c >6.5%-6.9% for identifying patients at higher risk of postoperative complications is most supported by the literature. We recommend obtaining these labs as part of routine pre-operative risk stratification. LEVEL OF EVIDENCE: III.