Pre-contoured patient-specific rods result in superior immediate sagittal plane alignment than surgeon contoured rods in adolescent idiopathic scoliosis.

Background: Adolescent idiopathic scoliosis (AIS) surgery typically involves posterior spinal fusion (PSF) using rods contoured by the surgeon, which may be time-consuming and may not reliably restore optimal sagittal alignment. However, pre-contoured patient-specific rods may more optimally restore sagittal spinal alignment. This study evaluates the radiographic outcomes of AIS patients who underwent PSF utilizing surgeon contoured vs. pre-contoured rods. Methods: This is a retrospective cohort study of AIS patients who underwent PSF with either surgeon contoured or pre-contoured rods. Demographics, Lenke classification, fused levels, osteotomies, estimated blood loss (EBL), and surgical time were also obtained via chart review. Coronal curve magnitude, T5-T12 thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL mismatch, and T1 pelvic angle (TPA) were obtained pre-operatively, postoperatively and at last follow up. Outcome measures included rate of achievement of postoperative radiographic alignment goals (TK between 20 and 40 degrees, PI-LL mismatch within 10 degrees, and TPA <14 degrees). Predicted post-operative sagittal alignment was also compared with observed measurements. Student's and paired t-tests were performed to determine significant mean differences for continuous variables, and chi-square for categorical variables. Results: No differences were found in demographics, Lenke classification, preop radiographic measurements, fused levels, osteotomies, EBL, and surgical time in the surgeon contoured cohort (n=36; average follow up 11.3 months) and pre-contoured cohort (n=22; average follow up 9.7 months). At last follow up, 95.5% of patients with pre-contoured rods vs. 61.1% of patients with surgeon contoured rods (P=0.004) met TK goal. During assessment of first standing postoperative X-ray, 72.7% of patients with pre-contoured rods vs. 33.3% of patients with surgeon contoured rods met PI-LL mismatch goal (P=0.004). Other radiographic measurements were similar. Artificial intelligence (AI) predicted and observed differences for the pre-contoured group were 3.7 for TK (P=0.005), -7.6 for PI-LL mismatch (P=0.002), and -2.6 for TPA (P=0.11). Conclusions: AI and pre-contoured rods help achieve global sagittal balance with high accuracy and improved kyphosis restoration and PI-LL mismatch than surgeon contoured rods in AIS patients.

Robotic Versus Navigation Assisted Posterior Lumbar Fusion: A National Database Study.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Compare perioperative adverse events and reoperations between navigation-assisted and robotic-assisted posterior lumbar fusion. SUMMARY OF BACKGROUND DATA: Navigation has become increasingly utilized for posterior lumbar fusion (PLF). More recently, robotic assistance systems have been gaining traction. However, the incremental advantage of these systems has been unclear in the literature. METHODS: Patients undergoing one to three level PLF (with or without anterior or posterior interbody fusion) were identified from the 2015-2022 M161Ortho PearlDiver Database using CPT codes. Navigation assistance was identified based on CPT coding and robotic assistance was based on ICD-10 procedural coding. Navigation-assisted cases were matched 4:1 to robotic assisted patients based on age, sex, Elixhauser Comorbidity Index, number of levels fuse, and concomitant anterior fusion. Incidence of 90-day adverse outcomes were assessed and compared with multivariable logistical regression. Bonferroni correction was applied for multiple testing. Rate of reoperation was assessed using a Kaplan-Meier survival analysis. RESULTS: From 2015 to 2022, there has been a significant increase in both navigation and robotic assisted lumbar fusions, with navigation-assisted surgery being significantly more common. After matching, there were 2,401 navigation-assisted cases and 651 robotic-assisted cases. On multivariate analysis, there no significant differences in 90-day any, severe, or minor adverse events. There was a significant increase odd of readmissions in the robotic cohort (OR: 1.77, P<0.001). There were no differences in three-year reoperation rates between the navigation-assisted and robotic-assisted cohorts (95.8% versus 94.0%, P=0.30). CONCLUSIONS: As spinal navigation has been gaining popularity and robotic assistance is starting to be further utilized, the incremental advantage of different techniques may be questioned. While further study and technique evolution are ongoing, the current study was not able to demonstrate 90-day or 3-year incremental advantages for robotics relative to navigation based on the metrics evaluated.

Outcomes of Distal Third Femur Fractures in Patients 18 Years and Older: A Pilot Study.

INTRODUCTION: The selection of the most optimal fixation method for fractures of the distal femur, whether intramedullary nail (NL), lateral locking plate (PL), or nail/plate (NP) is not always clear. This study retrospectively evaluates surgical patients with distal femur fractures and introduces a pilot study using cluster analysis to identify the most optimal fracture fixation method for a given fracture type. METHODS: This is a retrospective cohort study of patients 18 years and older with an isolated distal femur fracture who presented to our Level-1 trauma center between January 1, 2012, and December 31, 2022, and obtained NL, PL, or NP implants. Patients with polytrauma and those without at least six months of follow-up were excluded. A chart review was used to obtain demographics, fracture classification, fixation method, and postoperative complications. A cluster analysis was performed. The following factors were used to determine a successful outcome: ambulatory status pre-injury and 6-12 months postoperatively, infection, non-union, mortality, and implant failure. RESULTS: A total of 169 patients met inclusion criteria. No statistically significant association between the fracture classification and fixation type with overall outcome was found. However, patients treated with an NP (n = 14) had a success rate of 92.9% vs only a 68.1% success rate in those treated with a PL (n = 116) (p = 0.106). The most notable findings in the cluster analysis (15 total clusters) included transverse extraarticular fractures demonstrating 100% success if treated with NP (n = 6), 50% success with NL (n=2), and 78.57% success with PL fixation (n=14). NP constructs in complete articular fractures demonstrated success in 100% of patients (n = 5), whereas 77.78% of patients treated with NL (n = 9) and 61.36% of those treated with PL (n = 44). CONCLUSIONS: Plate fixation was the predominant fixation method used for distal third femur fractures regardless of fracture classification. However, NP constructs trended towards improved success rates, especially in complete intraarticular and transverse extraarticular fractures, suggesting the potential benefit of additional fixation with these fractures. Cluster analysis provided a heuristic way of creating patient profiles in patients with distal third femur fractures. However, a larger cohort study is needed to corroborate these findings to ultimately develop a clinical decision-making tool that also accounts for patient specific characteristics.

The Utilization of Press-Fit Total Knee Arthroplasty is Not Evenly Distributed: A National Registry Review.

BACKGROUND: This study evaluates trends of cemented versus press-fit total knee arthroplasty (TKA). We hypothesized that press-fit TKA is more common in younger and obese patients. There may also be racial, geographic, and institutional variation. METHODS: The American Joint Replacement Registry was used to conduct a retrospective review of primary TKA procedures for osteoarthritis in the United States between January 2019 and March 2022. The objective was to identify differences in incidence, demographics, body mass index (BMI), Charlson Comorbidity Index (CCI), and institutional teaching status (teaching vs. non-teaching) between press-fit and cemented TKAs. RESULTS: Two hundred ninety-seven thousand four hundred two patients (61% female, average age 68 years, 88.3% White) underwent cemented TKA versus 50,880 patients (52% female, average age 65 years, 89% White) underwent press-fit TKA. Overall, 20.8% of press-fit versus 19.9% of cemented TKA had a BMI of 35 to 39.9 and 15.2% of press-fit versus 12.5% of cemented TKA had BMI >40 ( P < 0.001). Patients undergoing press-fit TKA were less likely Black (OR = 0.727; P < 0.0001), Asian (OR = 0.651, P < 0.0001), and Native Hawaiian/other Pacific Islander (OR = 0.705, P < 0.02) with White as the reference group. Northeastern and Southern United States were more likely to use press-fit TKA than the Midwest (OR = 1.89 and OR = 1.87, P < 0.0001) and West (OR = 1.67; and OR = 1.65; P < 0.0001). Press-fit TKA incidence in 2019 was 9.9% versus 20.6% in 2022 ( P < 0.001). CONCLUSION: Press-fit TKA is increasingly more common in Northeastern and Southern United States, and patients are older than expected. Patients with BMI >35 had a slightly higher rate of undergoing press-fit than cemented TKA. Notable racial differences also exist. Additional research addressing racial disparities and evaluating longevity of press-fit designs is needed.

A 10-year perspective on the question of whether surgeries for adolescent idiopathic scoliosis are "one and done"?

PURPOSE: Posterior scoliosis fusion (PSF) for adolescent idiopathic scoliosis (AIS) is considered a highly successful surgery with excellent outcomes. However, especially as many patients "graduate" from their pediatric surgeons, there is the need to quantify the long-term outcomes of such surgeries. METHODS: The 2010-2022 Pearldiver M161 dataset was queried for those who were 10 to 18 years old with AIS undergoing PSF with at least 10 years follow-up. Patient characteristics were abstracted. Reoperations were identified based on coding for any subsequent thoracic/lumbar surgery/revision. The 10-year reoperation rate and reasons for reoperation were determined, and multivariate regression was performed to determine risk factors. RESULTS: In total, 3,373 AIS PSF patients were identified. Of the study cohort, 324 (9.6%) underwent reoperation within 10-years with an interquartile range for timing of surgery of 81-658 days, of which 29.6% were done for infection. Reoperations were done within the first three months for 152 (46.9% of reoperations), three months to 2 years for 97 (29.9%), and 2 years to 10 years for 74 (22.8%). Based on multivariate regression, need for reoperation was associated with male sex (OR: 1.70), asthma (OR: 1.36) and greater than thirteen segments of instrumentation (OR: 1.48) (p < 0.05 for each) but not age, other comorbidities, or insurance. CONCLUSIONS: The current study of a large national AIS PSF population found 9.6% to undergo reoperation in the 10 years following their index operation. Although specifics about the curve pattern could not be determined, the reoperation incidence and correlation with specific risk factors are notable and important for patient counselling.

Physical Therapy Utilization Following Single Level Posterior Lumbar Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: Characterize physical therapy (PT) utilization following single-level posterior lumbar fusion (PLF). SUMMARY OF BACKGROUND DATA: PLF is a common procedure that is increasing in frequency. Following such surgeries, PT may be considered to facilitate mobilization and return to activities. However, the usage of such therapy has not been well-characterized in the literature. METHODS: Patients undergoing single-level PLF were identified from the 2010-2021 PearlDiver administrative database. These patients were stratified based on usage of therapy, home versus outpatient therapy, and timing of therapy within the year following surgery. To determine predictors of therapy, patient characteristics were determined and multivariable regressions were performed. RESULTS: A total of 213,240 patients undergoing single-level PLF were identified, of which therapy was done in the year following surgery for 63,231 (29.0%, of which home therapy accounted for 16.5% of therapy visits). Of those who utilized PT, the average number of visits was 10.6±10.6. Home therapy peaked within the first month following surgery and outpatient therapy peaked at month two. Factors associated with any PT following PLF in decreasing odds ratio (OR) were: having commercial insurance (OR: 1.68), being from the Northeast (OR:1.41), age (OR: 1.13 for 70+ of age) female sex (OR: 1.09), and ECI (OR: 1.04 per point) (P<0.001 for all). Of those who received therapy, factors associated with home PT utilization were: being from the Northeast (OR: 2.55), age (OR: 1.91 for 70+ of age), Medicaid insurance (OR: 1.48), female sex (OR: 1.39), and interbody fusion (OR:1.07) (P<0.001 for all). CONCLUSIONS: Following single-level PLF, the minority of patients received home or outpatient PT. Of those that did, there was significant variation in the number of visits, with nonmedical factors such as insurance plan and geographic region being strongly associated suggesting room for more consistent practice patterns. LEVEL OF EVIDENCE: III.

Racial Disparities in Total Knee and Hip Arthroplasty in a Medically Underserved Community with a Diverse Population.

INTRODUCTION: Previous studies have demonstrated lower total joint arthroplasty utilization rates and worse postoperative outcomes among non-White patients. Our study examined whether these disparities exist in the setting of a diverse population. METHODS: This retrospective study included patients with a self-reported race who underwent total knee (TKA) or hip (THA) arthroplasty procedures in a racially diverse county. Patients who did not identify as White or Hispanic/Latino were excluded from the study due to small sample sizes. Demographic, intra and postoperative outcome differences were calculated. A multivariate logistic regression was developed to examine the association between patients' race and undesired postoperative outcomes. RESULTS: Five hundred fifty-five patients were included in our study with 490 identifying as non-Hispanic/Latino White (88.8%) and 65 as Hispanic/Latino (11.2%). Hispanic/Latino-identifying patients were significantly younger (61.9 ± 12.79 versus 68.58 ± 9.00 years), had lower Charlson Comorbidity Index scores, and were more likely to use non-Medicare/Medicaid insurance. We observed no differences between our cohorts in postoperative adverse events, emergency department visits, and hospital readmissions. Patients' self-identified race was not correlated with undesired postoperative outcomes. CONCLUSIONS: Although Hispanic/Latino-identifying patients constitute 50.2% of the county population of our study cohort, they accounted for only 11.2% of the patients in our study. This is noteworthy considering the lack of evidence suggesting a decreased prevalence of osteoarthritis among individuals of different races and ethnicities. Further, the demographic differences we observed suggest an exclusive Hispanic/Latino patient population utilizing TKA or THA procedures. Future studies controlling for risk factors and less invasive treatment options may explain these disparities.

3D printed pedicle screw guides reduce the rate of intraoperative screw revision in adolescent idiopathic scoliosis surgery.

BACKGROUND CONTEXT: Pedicle screw fixation has become common in the treatment of adolescent idiopathic scoliosis (AIS). Malpositioned pedicle screws have significant complications and identifying surgical techniques to optimize screw placement accuracy is imperative. PURPOSE: To compare the rate of intraoperative revision, replacement, or removal of pedicle screws placed utilizing 3D printed guides compared with pedicle screws placed utilizing a freehand technique. STUDY DESIGN/SETTING: Retrospective cohort study/single academic center. PATIENT SAMPLE: Thirty-two patients aged 10 to 18 with AIS. OUTCOME MEASURES: Revision rate of pedicle screws and operative time between groups. METHODS: A retrospective study was performed on patients 10 to 18 years of age who underwent posterior spinal instrumented fusion for AIS from February 2021 to July 2022. The study received an IRB exemption. Patient demographics, intraoperative measures, and outcome variables were recorded. Intraoperatively, all patients underwent a 3-dimensional fluoroscopic "check scan," which included axial, sagittal, and coronal images, to assess for screw accuracy. A secondary outcome of operative time was compared between groups. The p-values <.05 were considered significant. RESULTS: A total of 32 patients were included in this study. There were 17 cases in the 3D guided and 15 cases in fluoroscopy-guided freehand cohort. There was a total of 254 pedicle screws using 3D guides and 402 screws using freehand technique. Between cohorts, there were no significant differences in a number of levels fused (p=.54) or length of surgery (p=.36). The total revision rate of 3D guided screw placement was 5.5% and that of the freehand technique was 8.5%. The freehand screw placement group had significantly higher revision rates per vertebral level compared with 3D guided (p=.0096). Notably, 3D printed guides had fewer screws that were removed/revised for being too anterior (7.1%) compared with freehand (23.5%). Surgical time was not significantly different between the 3D guided and freehand cohort (p=.35). CONCLUSIONS: 3D printed guides reduce intraoperative revision rate compared with freehand techniques. Total operative time is comparable to freehand technique.

Localization of the Adductor Tubercle in the Skeletally Immature: A Computed Tomography Study With Patellofemoral Surgical Implications.

BACKGROUND: The adductor tubercle of the distal femur is utilized by surgeons as an anatomic landmark to identify graft anchor placement during medial patellofemoral ligament (MPFL) and medial quadriceps tendon femoral ligament (MQTFL) reconstruction for patellofemoral instability. In the skeletally immature population, its location relative to the physis has not been well defined. PURPOSE: To identify the location of the adductor tubercle relative to the distal femoral physis in skeletally immature individuals and gain insight regarding optimal graft anchor placement for pediatric patients undergoing MPFL and MQTFL reconstruction. STUDY DESIGN: Descriptive laboratory study. METHODS: Thin-cut computed tomography scans of 37 male cadaveric specimens (age, 4-16 years) were obtained from the New Mexico Decedent Image Database. A measurement protocol to identify the adductor tubercle was created with guidance from a fellowship-trained musculoskeletal radiologist. By utilizing axial, coronal, and sagittal views of knee computed tomography scans, the adductor magnus tendon was identified and followed distally to its insertion (adductor tubercle) on the distal femur. Distance from the midpoint of the adductor magnus tendon insertion relative to the physis in the proximal-distal orientation was measured. The anterior-posterior distance of the midpoint tendon insertion relative to the posterior femoral cortex line was also evaluated. RESULTS: The midpoint of the adductor magnus tendon was at the physis in 30 specimens. One 8-year-old cadaveric specimen had an insertion 1.1 mm distal to the physis. In all specimens ≥15 years old (n = 6), the adductor magnus tendon insertion was distal to the physis with a mean distance of 2.73 mm. The location of the adductor tubercle was always posterior (mean, 5.1 mm) with respect to the posterior femoral cortex line. CONCLUSION: The location of the adductor tubercle in male pediatric patients is likely at or distal to the physis. Thus, the findings of this study directly conflict with previous studies that suggested a more proximal location. CLINICAL RELEVANCE: Optimal graft anchor placement during MPFL and MQTFL reconstruction in the skeletally immature patient can be challenging because of the variability reported in previous studies of the medial patellofemoral complex origin relative to the physis. This study suggests that distal-rather than proximal-graft anchor placement might better help restore patellofemoral isometry.

Knee Arthrodesis for Mycobacterium avium Complex Native-Knee Septic Arthritis in a Patient with Dermatomyositis: A Case Report.

CASE: A 43-year-old woman with dermatomyositis presented with Mycobacterium avium complex (MAC) knee septic arthritis with superimposed polymicrobial infection. After poor infection control with antibiotic therapy, she underwent debridement and antibiotic cement spacer placement, followed by knee arthrodesis 6 months later. At 2-year follow-up, she had no pain and was ambulating without assistive devices. CONCLUSION: As far as we know, this is the first reported case of MAC native-knee septic arthritis successfully treated with antibiotic cement spacer followed by knee arthrodesis. This case sheds insight on treatment strategies for a rare native-knee infection.

Intrapelvic Pseudotumor Presenting with Deep Vein Thrombosis After Hip Replacement with Metal-on-Metal Bearing Surface Implant: A Case Report.

CASE: A 61-year-old woman with an asymptomatic hip presented acutely with a swollen lower limb 15 years after a metal bearing surface total hip replacement (THR). A large intrapelvic pseudotumor was discovered compressing her femoral and iliac vessels. Collaboration between an orthopaedic and vascular surgeon led to a 2-stage surgical procedure with resection of the pseudotumor, followed by revision of the THR implant 3 months later. CONCLUSION: This case demonstrates the importance of long-term follow-up of patients with metal bearing surface implants, early recognition of an unusual presentation of a common problem, and the utility of collaboration between orthopaedic and vascular surgeons.

Short-segment minimally disruptive anterior column release for focal sagittal deformity correction of the thoracolumbar spine.

BACKGROUND: Sagittal malalignment is associated with poor quality of life. Correction of lumbar lordosis through anterior column release (ACR) has been shown to improve overall sagittal alignment, however typically in combination with long posterior constructs and associated morbidity. The technical feasibility and radiographic outcomes of short-segment anterior or lateral minimally invasive surgery (MIS) ACR techniques in moderate to severe lumbar sagittal deformity were evaluated. METHODS: Consecutive patients treated with short-segment MIS ACR techniques for moderate to severe lumbar sagittal deformity correction were retrospectively analyzed from a prospectively collected database. Clinical outcomes included perioperative measures of invasiveness, including operative time, blood loss, complications, and average length of stay. Radiographic outcomes included measurement of preoperative, immediate postoperative, and long-term follow-up radiographic parameters including coronal Cobb angle, lumbar lordosis (LL), pelvic incidence (PI), PI-LL mismatch, pelvic tilt (PT), T1 pelvic angle (TPA), T1 spino-pelvic inclination (T1SPI), proximal junctional angle (PJA), and sagittal vertical axis (SVA). RESULTS: The cohort included 34 patients (mean age 63) who were treated at an average 2.5 interbody levels (range 1-4) through a lateral or anterior approach (LLIF or ALIF). Of 89 total interbody levels treated, 63 (71%) were ACR levels. Posterior fixation was across an average of 3.2 levels (range 1-5). Mean total operative time and blood loss were 362 minutes and 621 mL. Surgical complications occurred in 2 (5.9%). Average hospital stay was 5.5 days (including staging). At last follow-up (average 25.4 months; range 0.5-7 years), all patients (100%) demonstrated successful achievement of one or more alignment goal, with significant improvements in coronal Cobb, LL, PI-LL mismatch, PT, and TPA. No patient was revised for PJK. CONCLUSIONS: These data show that short-segment MIS ACR correction of moderate to severe lumbar sagittal deformity is feasible and effective at achieving overall alignment goals with low procedural morbidity and risk of proximal junctional issues.

A paradoxical method to enhance compensatory lung growth: Utilizing a VEGF inhibitor.

Exogenous vascular endothelial growth factor (VEGF) accelerates compensatory lung growth (CLG) in mice after unilateral pneumonectomy. In this study, we unexpectedly discovered a method to enhance CLG with a VEGF inhibitor, soluble VEGFR1. Eight-week-old C57BL/6 male mice underwent left pneumonectomy, followed by daily intraperitoneal (ip) injection of either saline (control) or 20 µg/kg of VEGFR1-Fc. On post-operative day (POD) 4, mice underwent pulmonary function tests (PFT) and lungs were harvested for volume measurement and analyses of the VEGF signaling pathway. To investigate the role of hypoxia in mediating the effects of VEGFR1, experiments were repeated with concurrent administration of PT-2385, an inhibitor of hypoxia-induced factor (HIF)2α, via orogastric gavage at 10 mg/kg every 12 hours for 4 days. We found that VEGFR1-treated mice had increased total lung capacity (P = 0.006), pulmonary compliance (P = 0.03), and post-euthanasia lung volume (P = 0.049) compared to control mice. VEGFR1 treatment increased pulmonary levels of VEGF (P = 0.008) and VEGFR2 (P = 0.01). It also stimulated endothelial proliferation (P < 0.0001) and enhanced pulmonary surfactant production (P = 0.03). The addition of PT-2385 abolished the increase in lung volume and endothelial proliferation in response to VEGFR1. By paradoxically stimulating angiogenesis and enhancing lung growth, VEGFR1 could represent a new treatment strategy for neonatal lung diseases characterized by dysfunction of the HIF-VEGF pathway.