Study Design: Retrospective case series. Objective: To evaluate the clinical outcomes and variables associated with recurrent acute spondylolysis and progression to chronic spondylolysis in a cohort of adolescent athletes who were treated nonoperatively for acute spondylolysis with a protocol of rest, bracing, and physical therapy (PT). Background: The optimal nonoperative treatment algorithm for spondylolysis in adolescent athletes remains unclear. Patients and Methods: Acute spondylolysis was defined as a stress reaction/defined pars interarticularis fracture with edema on MRI from February 2016 to August 2024. All patients were treated nonoperatively with a period of rest, bracing, and PT. Outcomes included clinical resolution of pain, recurrence of pain, recurrent acute spondylolysis, progression to chronic spondylolysis, and surgical intervention. Multivariable logistic regression identified variables associated with recurrent acute spondylolysis and progression to chronic spondylolysis, respectively. Results: One hundred seventy-nine adolescents (mean: 14.4 ± 1.6 y) with acute spondylolysis were treated with rest, bracing for 11.0 ± 2.3 weeks, and PT initiation at 5.9 ± 1.6 weeks into treatment. Clinical resolution was achieved in 79% at first follow-up (mean: 6.8 ± 2.2 wk) and 96% by the second follow-up (13.9 ± 3.6 wk). Seventy-eight (44%) had recurrent pain; 19 (10.6%) developed recurrent acute spondylolysis, and 15 (8.4%) progressed to chronic spondylolysis. Five (2.8%) patients required surgical intervention (4 L5/S1 fusions, 1 pars fixation). An additional week of bracing was associated with 22% decreased odds (OR: 0.78, P = 0.019) of recurrent acute spondylolysis. Multilevel spondylolysis (OR: 8.21, P = 0.038), persistent pain at second follow-up (OR: 10.65, P = 0.009), and each week delay in initiating PT (OR: 1.43, P = 0.013) were associated with higher odds of recurrent acute spondylolysis. Persistent pain at the first follow-up visit was associated with higher odds (OR: 4.95, P = 0.005) of progression to chronic spondylolysis. Conclusion: Our findings demonstrate the success of our spondylolysis protocol involving 12 weeks of bracing with initiation of physical therapy at four to six weeks following rest, and identify specific variables associated with nonresolving acute spondylolysis.

Background: The optimal surgical treatment of Ogden Type IV tibial tubercle avulsion fractures (TTAFs) remains controversial, given this injury pattern’s rarity and its multiplanar involvement of the proximal tibial physis. Small, single-center studies suggest type IV fractures have higher complication rates and more variable fixation constructs than other TTAF types. The purpose of this study is to delineate fixation constructs among surgically managed type IV TTAFs and identify factors associated with postoperative complications. Methods: A retrospective, multicenter cohort study was conducted across 7 institutions examining surgically managed Ogden IV TTAFs treated between 2007 and 2022. Patients treated nonoperatively were excluded. Patient demographics, injury characteristics, treatment strategy (including fixation construct), and postoperative complications were analyzed. Fisher exact tests were used to compare complication frequency among fixation techniques. Results: Eighty-nine patients undergoing operative management of a type IV TTAF meeting study criteria were identified. The majority (72, 80.9%) were stabilized with screw-only constructs, while 9 (10.1%) were treated with pins or hybrid pin/screw constructs and the remainder (9.0%) were treated with a plate. Among screw-only constructs, 4.5 mm screws (49, 58%) with vertically stacked orientation (37, 51.3%) were the most common. Twenty-five patients (28.0%) experienced complications, the most common of which were implant irritation (14.6%) and wound problems (3.4%). One patient (1.1%) had postoperative compartment syndrome. When examining major complications (excluding implant irritation), the frequency was lower for screw-only constructs than other types of fixation (6.9% vs. 35.3%; P = .005). For fractures fixed with screws only, there was no difference in overall complications based on the number of screws used (P = .21). No implant failures or nonunions were observed. Conclusions: In this large, multicenter cohort of surgically managed type IV TTAFs, considerable variation was observed among successful fixation constructs. Implant irritation was the most commonly observed complication. Other than implant irritation, the overall frequency of complications was low and lowest among screw-only constructs. Key Concepts: (1) A variety of fixation options exist for type IV tibial tubercle avulsion fractures. (2) There was reliable healing and good outcomes in the majority of cases. (3) Implant irritation is the most common complication in screw-only constructs. (4) Anterior-to-posterior screws can provide acceptable fixation for type IV fractures. Level of Evidence: Level III

Background: Idiopathic clubfoot is typically corrected with the Ponseti method, involving foot manipulation and serial casting followed by possible Achilles tenotomy and bracing. This process causes distress, but the quantification of infant distress during longitudinal casting visits has not been evaluated. The primary aim of this pilot study was to assess infant distress longitudinally across weekly casting sessions among children with clubfeet. Secondary aims included identifying patient characteristics associated with infant distress. Methods: Ten patients with idiopathic clubfoot were prospectively enrolled in this pilot study. Prenatal counseling, family history, baseline parental anxiety, and demographic data were recorded at the initial visit. The patient’s pain response was assessed by the Neonatal Infant Pain Scale (NIPS) and heart rate (HR) at 5 designated casting steps during each visit. The primary outcome measures were NIPS score and HR at each casting step throughout the entire course of casting (ie, longitudinally across casting visits). HR range for each casting step was also recorded at every visit. Additionally, univariable and multivariable analyses were performed to identify predictors of infant distress. Results: There was a significant increase in NIPS across visits at casting steps 1, 2, and 3 ( P = .03, P = .01, P = .05) and in HR at each of the 5 casting steps ( P < .001, P < .001, P < .001, P < .001, P = .003). With the numbers available, no significant difference in HR range could be detected across visits ( P = .51). Multivariable analysis demonstrated that visit number was independently associated with infant distress. Conclusion: This pilot study suggests that infant distress at certain casting steps increases from mild at the first visit to moderate at subsequent visits. The magnitude of heart rate elevation within each visit did not significantly change across visits in this pilot cohort, although whether this reflects infant acclimation or other factors warrants further investigation. Level of Evidence: Level IV, prospective pilot study.

BACKGROUND:Spirometry remains the clinical gold standard for measuring pulmonary function such as forced expiratory indices; however, reliance on a mouthpiece seal, quality assurance, and infection control procedures limit feasibility and degrade data quality. Markerless optical approaches (depth cameras and surface topography) show promise in monitoring quiet breathing but often require patient-specific calibration, with limited validation of forced expiratory indices and formal reliability testing. RESEARCH QUESTION:Can markerless surface topography (ST) provide reliable estimates of FEV1, FVC, and FEV1/FVC comparable with spirometry? STUDY DESIGN AND METHODS:Twenty healthy volunteers underwent prospective simultaneous ST and handheld spirometry during standardized forced expiratory maneuvers. Two raters administered multiple trials per patient. Body volume was computed per frame from reconstructed surface meshes. Intrarater and interrater reliability were assessed using intraclass correlation coefficients (ICCs) (ICC2,1) with paired permutation testing for differences. ST-spirometry agreement was evaluated by Pearson correlations and Bland-Altman analysis. Leave-one-out cross validation tested generalizability of a universal linear correction mapping ST volumes to spirometry. RESULTS:ST and spirometry demonstrated similar reliability for FEV1 (ICC > 0.97), FVC (ICC > 0.96), and FEV1/FVC ratio (ICC > 0.89), with no significant ICC differences between modalities or raters (all P > .10). ST correlated strongly with spirometry (R = 0.95 for FEV1, R = 0.94 for FVC, R = 0.93 for FEV1/FVC ratio). Bland-Altman analysis showed stable negative bias for absolute volumes (FEV1, -0.52 L; FVC, -0.66 L) and negligible bias for FEV1/FVC. Cross validation yielded low root mean square errors (FEV1, 0.24 L; FVC, 0.34 L; FEV1/FVC ratio, 0.025). INTERPRETATION:Our results show that ST provides contact-free forced expiratory estimates that correlate strongly with spirometry, with comparable reliability. This may benefit populations for whom the spirometer interface is a barrier, including young children and those with bulbar dysfunction or craniofacial abnormalities.

Pedicle screws can be placed using freehand technique, navigation, or robotic-assisted navigation (RAN). There is a steep learning curve for RAN in pediatric spine deformity. This study aimed to compare pedicle screw accuracy, precision, and incidence of breach using RAN between a pediatric spine surgeon with 3 years of RAN experience and a fourth-year orthopedic resident who had completed pediatric- and adult-spine rotations with RAN training. A preoperative computed tomography (CT) scan was obtained on two adult cadavers. The resident and attending each placed T2-L5 screws bilaterally in one cadaver each using RAN. A computer-vision algorithm was used to compare the postoperative CT screw position to the preoperatively planned screw position. Laminectomies were performed to assess breach. Statistical analysis compared systematic error (signed mean error), precision (2 standard deviations), and accuracy (mean absolute error) between training levels for angular deviation and translational deviation at the screw tip, tail, and mid-pedicle positions in the medial-lateral (ML) and superior-inferior (SI) directions. Fifty-seven screws were placed in two cadavers. The attending screws were more precise and accurate than the resident screws in the ML direction at the tail and mid-pedicle positions, and more precise in the ML direction at the tip (P < 0.05). Resident screws had better systematic error and accuracy than attending screws in the SI direction at the tip, tail, and mid-pedicle positions (P < 0.02). There were no significant differences in systematic error, precision, and accuracy in the angular deviation between resident and attending. All breaches were <1 mm (1 attending, 2 resident). This cadaveric study identified that increased surgical experience may increase accuracy and precision when placing screws in the clinically important medial-lateral direction of the pedicle when using RAN. Although the fourth-year orthopedic surgery resident with a spine rotation as well as an introduction to robotic surgery rotation placed clinically safe pedicle screws using RAN without breach, this study demonstrates that 3D accuracy metrics paired with RAN can help identify specific opportunities for improvement in surgical technique for trainees. Level of evidence II.

BACKGROUND:Robotic-assisted navigation (RAN) during posterior spinal fusion and instrumentation (PSFI) for pediatric patients with idiopathic scoliosis has been increasingly adopted over the traditional freehand (FH) technique due to enhanced accuracy. RAN requires either intraoperative or preoperative three-dimensional imaging or computed tomography (CT). Safety concerns, therefore, exist with regard to radiation exposure for the patient and surgeon, who have been shown to experience higher cancer rates than the general population. The objective of this study was to compare the mean intraoperative fluoroscopy radiation dosage and total perioperative radiation dosage between RAN and FH. METHODS:One hundred and twenty-one patients with idiopathic scoliosis who underwent PSFI were included (41 FH, 80 RAN). Patients underwent FH pedicle screw placement with fluoroscopy assistance, or RAN (Mazor, Medtronic), using a preoperative CT and fluoroscopy-to-CT registration intraoperatively. The mean intraoperative fluoroscopy radiation dose in millisieverts (mSv) and total perioperative radiation dose (preoperative CT + intraoperative fluoroscopy) in mSv were compared by one-way analysis of covariance, controlling for preoperative curve magnitude, body mass index, and number of levels fused. Significance was set at P ≤0.05. RESULTS:The mean intraoperative fluoroscopy dose was 0.5±0.2 and 0.4±0.1 mSv for FH and RAN, respectively. Mean cumulative radiation doses for FH and RAN were 0.5±0.2 and 12.5±4.7 mSv, respectively. RAN had lower intraoperative radiation than FH ( P <0.001), but FH had a significantly lower cumulative perioperative dosage than RAN ( P <0.001). CONCLUSIONS:RAN had a 1.5-fold decrease in intraoperative radiation but a 25-fold greater total radiation compared with FH, representing lower radiation exposure to the surgeon but a much higher exposure to the patient. Literature demonstrates the potential efficacy of low-dose CT and, paired with our findings, suggests that there is room for improvement in radiation exposure in the robotic field. Surgeons must try to reduce radiation exposure for patients when feasible and reassess surgical practice and imaging protocols. LEVEL OF EVIDENCE:Level III.

BACKGROUND CONTEXT Posterior spinal fusion (PSF) was traditionally performed freehand. Robotic-assisted navigation (RAN) allows for increased accuracy/precision of pedicle screw (PS) placement by robotically establishing/maintaining the trajectory for drilling pedicle tracts and placing screws. However, RAN presents a steep learning curve. PURPOSE This study aimed to compare the 3D accuracy/precision of PS placement between an attending surgeon with RAN experience and a 4th-year orthopaedic surgery resident who completed an adult and pediatric spine orthopedic rotation with an introduction to robotic surgery. STUDY DESIGN/SETTING Cadaveric study. PATIENT SAMPLE Two adult cadavers. OUTCOME MEASURES Systematic error, precision, and accuracy between training levels for angular deviation and translational deviation. METHODS Two cadavers were utilized, one each by attending and resident. Cadavers underwent subperiosteal exposure from T2-L5, and subsequently PS were placed using RAN from T2-L5. Preoperative CT scans were used to plan screws; plans were transposed to the robotic planning platform. A computer-vision algorithm compared the postoperative CT screw position to the preoperatively planned screw position. Laminectomies were performed to assess breach. Systematic error (signed mean error), precision (2SD), and accuracy (mean absolute error) were statistically compared between training levels for angular and translational deviation at the screw tip/tail/mid-pedicle positions in the medial-lateral (ML) and superior-inferior (SI) directions. RESULTS Fifty-seven PS were placed in two cadavers. Attending screws were more precise and accurate than the resident screws in the ML direction at the tail and mid-pedicle positions, and attending screws were more precise in the ML direction at the tip (P<0.021). Resident screws had better systematic error and accuracy than attending screws in the SI direction at the tip, tail, and mid-pedicle positions (P<0.024). There were no differences in angular deviation performance metrics. All breaches were <1mm (1 attending, 2 resident). CONCLUSIONS This cadaveric study identified that increased surgical experience may increase accuracy and precision when placing screws in the clinically important medial-lateral direction of the pedicle when using RAN. Although the fourth-year orthopedic surgery resident with a spine rotation as well as an introduction to robotic surgery rotation placed clinically safe pedicle screws using RAN without breach, this study demonstrates that 3D accuracy metrics paired with RAN can help identify specific opportunities for improvement in surgical technique for trainees. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

This study compares the range of motion (ROM) in all three planes in patients with Scheuermann kyphosis (SK) to healthy controls using surface topographic (ST) scanning. SK patients and healthy controls between 11–21 years old were recruited prospectively. Patients underwent ST scanning in maximal forward bend, twist to the right and left, and side-bend to the right and left. Sagittal, axial, and coronal ROM were computed using an automated pathway. An analysis of variance was used to determine significant differences in the ROM (coronal, axial, and sagittal) and asymmetry (coronal and axial) of SK patients versus controls. Scoliosis Research Society (SRS) 22r total, self-image, pain and function, as well as Patient-Reported Outcome Measurement Information System (PROMIS) mobility, physical activity and pain interference scores, and HSS Pedi-FABS were collected for all patients. 23 patients with SK and 98 controls were analyzed. SK group was 78.3

Background:Persistent stiffness after operative treatment of tibial tubercle fractures (TTFs) can inhibit functional recovery and interfere with activities of daily living. Given the rare nature of this fracture, little data exist to help identify risk factors for this complication. The purpose of this multicenter study was to identify risk factors for stiffness after fixation of TTFs. Methods:Operatively managed TTFs at 7 tertiary children's hospitals in patients younger than 18 years were included in this retrospective comparative study. Fractures with <3 months of documented postoperative range of motion and those fixed with nonscrew implants were excluded. Demographic, clinical, and radiographic data were reviewed. Persistent stiffness was defined as lacking ≥20° of flexion compared with the contralateral knee at 3 months after surgery. Univariable analysis was followed by multivariate regression to adjust for confounders. Results:The incidence of prolonged stiffness among the 369 included patients was 3.0%. The median time between initial presentation and surgery was longer in those who developed stiffness (24 versus 14 hours, p = 0.002). Furthermore, those who had surgery >24 hours after presentation developed stiffness more often than those who underwent fixation within 24 hours (12.7% versus 1.6%, p < 0.001). The median duration of postoperative immobilization was longer in patients who developed stiffness (45 versus 28 days, p = 0.006). Children immobilized >4 weeks after surgery developed stiffness more frequently than those who initiated mobilization within 4 weeks (5.7% versus 0.6%, p = 0.009). When adjusting for confounders such as age and fracture classification, fixation >24 hours after presentation was associated with 9.7 times higher odds of stiffness (95% CI 2.0-46.5, p = 0.004) and postoperative immobilization >4 weeks had 10.3 times higher odds of stiffness (95% CI 1.1-95.0, p = 0.04). Conclusions:Persistent stiffness after surgical fixation of TTFs occurs in 3.0% of children. Prolonged postoperative immobilization (>4 weeks) and delayed surgical fixation (>24 hours) are associated with higher odds of a persistent flexion deficit 3 months after surgery. Surgeons should consider this information when determining timing of treatment and postoperative protocols. Level of Evidence:Level III, retrospective comparative study. See Instructions for Authors for a complete description of levels of evidence.

Background:Idiopathic clubfoot is a congenital disorder necessitating time-sensitive treatment. Delayed application of the Ponseti method may result in poorer outcomes. Adverse social determinants of health, as measured with the Childhood Opportunity Index version 3.0, hinder access to care. This study aimed to determine the association between Childhood Opportunity Index, insurance status, and treatment disparities for patients with idiopathic clubfoot. Methods:This retrospective cohort study included patients with idiopathic clubfoot who underwent Ponseti treatment at an urban tertiary care orthopedic hospital between October 2004 and September 2022. Patients presenting for care before 6 months of age and with a minimum 2-year follow-up were included. A threshold Childhood Opportunity Index value of 60.0 categorized patients into low (<60.0) and high (≥60.0) cohorts. Clinical and treatment/outcome variables were compared. Results:A total of 156 patients (mean follow-up 5.1 ± 2.5 years) merited inclusion: 31 (20%) with Childhood Opportunity Index <60 and 125 (80%) with Childhood Opportunity Index ≥60. Patients with low Childhood Opportunity Index presented at older ages (18 ± 23 versus 11 ± 10 days, p = 0.03) and had fewer prenatal orthopedic evaluations (42% versus 64%, p = 0.03). Recurrence and necessity for further treatment were similar (p > 0.05). Patients with public insurance presented at older ages (28 ± 31 versus 10 ± 9 days, p < 0.01) and were less likely to undergo prenatal consultation (13% versus 65%, p < 0.01). Black/Hispanic patients were more likely to experience a recurrence (odds ratio 6.4, 95% confidence interval 1.2-35.4, p = 0.03), whereas patients who had a prenatal orthopedic evaluation were less likely to experience a recurrence (odds ratio 0.3, 95% confidence interval 0.1-0.9, p = 0.03). Conclusions:Patients with idiopathic clubfoot and low Childhood Opportunity Index/public insurance experienced delayed presentation to care and fewer prenatal orthopedic consultations. However, low Childhood Opportunity Index and public insurance status were not associated with adverse treatment outcomes. Clubfoot specialists remain a critical component of the multidisciplinary prenatal team, as orthopedic consultations served as a protective factor against recurrence. These findings contribute to the existing literature by highlighting discrepancies in the care for patients with adverse social determinants of health. Level of evidence:Level III.

BACKGROUND CONTEXT Computer-assisted navigation (NAV) and robotic-assisted navigation (RAN) for pedicle screw placement in posterior spinal fusion (PSF) have been increasingly adopted over the freehand technique (FH). Both RAN and NAV require either intraoperative three-dimensional imaging or preoperative computed tomography (CT). Safety concerns exist with regards to radiation exposure for both the patient and surgeon, who experience higher cancer rates than the general population. PURPOSE The objective of this study was to compare mean intraoperative fluoroscopy time, fluoroscopy radiation dosage, and total radiation dosage (including preoperative CT) for RAN, NAV, and FH. STUDY DESIGN/SETTING This study was a single institution retrospective review between 9/2021 and 12/2024. PATIENT SAMPLE A total of 135 patients with adolescent or juvenile idiopathic scoliosis (IS) who underwent PSF were included: 41 FH, 12 NAV, and 82 RAN. The mean age was 14.8 years (range, 10.0 to 20.0), the mean body mass index (BMI) was 21.8 (range, 14.0 to 40.7), and 66.7% of patients were female. OUTCOME MEASURES Primary outcome measures were mean intraoperative fluoroscopy time, mean intraoperative fluoroscopy dosage, and cumulative surgery-related radiation exposure (including preoperative CT). METHODS Patients either underwent FH pedicle screw placement with fluoroscopy assistance, NAV using CT-guided navigation (FLASH, 7D Surgical) that utilized a preoperative CT, or RAN (Mazor, Medtronic), using a preoperative CT and fluoroscopy-to-CT registration intraoperatively. All patients had routine use of the C-arm intraoperatively to check screws and patient alignment during the procedure. The mean fluoroscopy time in seconds, fluoroscopy radiation dose in milliGray (mGy), and total radiation dose (including preoperative CT and intraoperative fluoroscopy) in mGy were compared by one-way analysis of covariance (ANCOVA) among the cohorts followed by pairwise comparisons, controlling for preoperative curve, BMI, and number of levels fused. Significance was set at p<0.05. RESULTS The average fluoroscopy time was 66.5 ± 25.6, 31.8 ± 8.0, and 49.7 ± 13.8 seconds for FH, NAV, and RAN, respectively. The RAN cohort had a lower mean fluoroscopy time than FH (p < 0.001) and the NAV cohort had a lower mean fluoroscopy time than both FH (p < 0.001) and RAN (p = 0.028). The average intraoperative fluoroscopy dose was 7.6 ± 4.5, 3.5 ± 1.7, and 7.1 ± 4.9 mGy for FH, NAV, and RAN, respectively. The NAV cohort had a lower mean fluoroscopy dosage than FH (p = 0.03), but there was no difference between FH and RAN (p = 1.00) or NAV and RAN (p = 0.065). When accounting for preoperative CT radiation dose, FH (7.6±4.5 mGy) had a significantly lower mean total radiation dose than NAV (21.9±3.3 mGy, p < 0.001) and RAN (26.6 ± 9.6, p < 0.001). There was no significant difference between NAV and RAN in regards to overall radiation dose (p = 0.486). CONCLUSIONS In this series of PSF for IS, NAV was associated with a 2-fold decrease in intraoperative radiation, but a higher total radiation dosage compared to FH, representing a potentially lower radiation exposure to the surgeon but higher exposure to the patient. As NAV and RAN become increasingly adopted for their increased accuracy and reliability of pedicle screw placement, it is important to be aware of the cumulative radiation exposure to surgeons, patients, and the operating room staff and to take proper precautions when feasible. FDA Device/Drug Status This abstract does not discuss or include any applicable devices or drugs.

INTRODUCTION:After posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS), there is alteration in trunk range of motion (ROM) in the coronal, sagittal and axial planes. Previous studies have shown that ROM decreases with increased number of levels fused, which may affect the ROM between patients who undergo non-selective thoracic fusion (NSF) and selective thoracic fusion (STF) patient groups. This study sought to longitudinally evaluate the ROM of the trunk in patients with AIS who underwent posterior spinal fusion, using surface topography, comparing STF and NSF patient motion at multiple time points postoperatively. METHODS:A retrospective review of data from a single-center prospective registry was conducted. Inclusion criteria required subjects to span 11-21 years of age at surgery, a diagnosis of AIS, and valid ROM measurements obtained via ST scanning. Axial, sagittal and coronal ROM was performed at six timepoints: preoperative, 6 weeks, 3, 6, 12, and 24 months postoperative. All patients had an upper instrumented vertebra (UIV) of T2, T3 or T4, and a lower instrumented vertebra (LIV) of T12, L1, L2 or L3. STF was defined as an LIV of T12 or L1, and NSF as LIV as L2 or L3. SRS22r was collected at all time points. Generalized estimation equation modeling across timepoints were conducted. RESULTS:54 patients were evaluated: 40 patients in the NSF group (average preoperative Cobb angle of 56.4 ± 12.3°) and 14 in the STF group (average preoperative Cobb angle of 57.4° ± 6.7°). In the NSF group, ROM in the coronal and axial planes decreased significantly postoperatively and remained significantly decreased at 24 months postoperatively (25% decrease in the axial plane, 20% in the coronal plane). Sagittal ROM had significant decrease in ROM at all time points, but at 2 years postoperatively was no longer significant, although still 17% decreased. In the STF group, all three planes had significantly decreased initially but axial and coronal planes returned to baseline (no significant difference from preoperative values) at 24 months, while sagittal plane motion remained significantly diminished, although only by 4%. STF demonstrated no difference in SRS22r total, pain or self-image scores between preoperative and 2 years, while NSF had worse SRS22r total, pain, and self image scores at 2 years vs. preoperative values. When comparing NSF to STF, there was diminished axial, sagittal and coronal plane range of motion at 24 months postoperatively, but no differences in SRS22r total. CONCLUSION:The coronal, sagittal, and axial ROM as measured by ST demonstrated significant decreases from preoperative to postoperative following PSF; however, this deficit trends towards improvement over time. Our data demonstrates that at two years, NSF has poorer motion than STF patients in all three planes.

Background: Tibial tubercle fractures are typically treated surgically with screws. Implant irritation is the most common complication. However, detailed investigation of this problem is challenging, since most research is limited to small, single-center studies. Understanding who is at the highest risk may improve patient counseling and potentially guide surgical techniques. The purpose of this study is to identify risk factors for implant irritation in patients undergoing fixation of tibial tubercle fractures. Methods: This retrospective cohort study included tibial tubercle fractures fixed with screws at 7 tertiary children’s hospitals in the Tibial Tubercle Study (TITUS) Group. Exclusion criteria included age 18 years or older, primary fixation with nonscrew implants, or <6 months of follow-up. Demographic, perioperative, and postoperative data was collected. The primary outcome of interest was postoperative implant irritation. Univariable analysis was followed by multivariable regression to adjust for confounders. Odds ratios (OR) are reported with 95% CIs. Results: Of the 475 patients included, implant irritation was reported in 12.8% while 10.7% subsequently underwent unplanned removal. Patients weighing <70 kg reported more irritation than those weighing 70 kg or more (17.3% vs. 9.4%, P =0.01). However, in patients weighing <70 kg, there was no difference in the rate of symptomatic implants when stratifying by screw size. White patients reported more irritation than nonwhite patients (24.8% vs. 9.6%, P <0.001). Significant institutional variation in implant irritation rates was reported, ranging from 0% to 29% ( P =0.004). Screw number, size, configuration, washer use, or pre-existing Osgood-Schlatter syndrome were not associated with symptomatic implants. When adjusting for confounders in multivariable analysis, white patients (OR: 3.2, 95% CI: 1.5-6.6; P =0.002) and those weighing <70 kg (OR: 2.2, 95% CI: 1.2-4.2; P =0.02) had higher odds of experiencing implant irritation. One of the 7 study sites was also independently associated with increased odds of symptomatic screws (OR: 7.8, 95% CI: 1.1-54.9; P =0.04). Conclusions: Implant irritation was reported by 12.8% of patients following screw fixation of a tibial tubercle fracture. Even when accounting for institutional variability, white patients and those weighing <70 kg had higher odds of symptomatic screws. This information can be used to enhance patient counseling and potentially adjust surgical techniques in some patients. Level of Evidence: Level III.

BACKGROUND:Genu valgum is a well-known feature of multiple hereditary exostoses (MHE). Though prior reports have demonstrated successful treatment with hemiepiphysiodesis, details regarding the correction rate and comparison to an idiopathic population are lacking. This study aimed to detail our institution's experience with guided growth of the knee in patients with MHE and compare this to an idiopathic population.METHODS:All pediatric patients (age 18 and younger) with MHE who underwent lower extremity hemiepiphysiodesis at a tertiary care medical center between January 2016 and December 2022 were retrospectively reviewed. Preoperative and postoperative mechanical lateral distal femoral angle (mLDFA) and medial proximal tibial angle (MPTA, the primary outcomes) were measured in addition to mechanical axis deviation (MAD) and hip-knee-ankle angle (HKA). Patients were 1:2 matched based on age, sex, and physes instrumented to a cohort with idiopathic genu valgum.RESULTS:A total of 21 extremities in 16 patients with MHE underwent hemiepiphysiodesis of the distal femur, proximal tibia, and/or distal tibia. The mean age at surgery was 11.7±2.2 years. Mean MAD corrected from zone 1.9±0.7 to -0.3±1.5, while mLDFA corrected from 83.4±2.9 to 91.7±5.2 degrees and MPTA corrected from 95.3±3.6 to 90.5±4.0 degrees in distal femurs and proximal tibias undergoing guided growth, respectively. Three extremities (14.3%) experienced overcorrection ≥5 degrees managed with observation. There were no differences in correction rates per month for mLDFA (0.54±0.34 vs. 0.51±0.29 degrees, P =0.738) or MPTA (0.31±0.26 vs. 0.50±0.59 degrees, P =0.453) between MHE and idiopathic groups. For 11 extremities in the MHE group with open physes at hardware removal, they experienced a mean recurrence of HKA of 4.0±3.4 degrees at 19-month follow-up.CONCLUSION:Hemiepiphysiodesis corrects lower extremity malalignment in patients with MHE at a similar rate compared with an idiopathic coronal plane deformity population. Rebound deformity of 4 degrees at 19 months after hardware removal in patients with remaining open growth plates should make surgeons conscious of the remaining growth potential when planning deformity correction.LEVEL OF EVIDENCE:Level III.

BACKGROUND:The Pavlik harness has been used for approximately a century to treat developmental dysplasia of the hip (DDH). Femoral nerve palsy is a documented complication of Pavlik harness use, with an incidence ranging from 2.5% to 11.2%. Rare reports of brachial plexus palsy have also been documented. The primary purpose of the current study was to evaluate the incidence of various nerve palsies in patients undergoing Pavlik harness treatment for DDH. Secondary aims were to identify patient demographic or hip characteristics associated with nerve palsy. METHODS:We performed a retrospective review of patients diagnosed with DDH and treated with a Pavlik harness from February 1, 2016, to April 1, 2023, at a single tertiary care orthopaedic hospital. Hip laterality, use of a subsequent rigid abduction orthosis, birth order, breech positioning, weight, and family history were collected. The median (and interquartile range [IQR]) or mean (and standard deviation [SD]) were reported for all continuous variables. Independent 2-sample t tests and Mann-Whitney U tests were conducted to identify associations between the variables collected at the initiation of Pavlik harness treatment and the occurrence of nerve palsy. RESULTS:Three hundred and fifty-one patients (547 hips) were included. Twenty-two cases of femoral nerve palsy (4% of all treated hips), 1 case of inferior gluteal nerve palsy (0.18%), and 2 cases of brachial plexus palsy (0.37%) were diagnosed. Patients with nerve palsy had more severe DDH as measured by the Graf classification (p < 0.001) and more severe DDH as measured on physical examination via the Barlow and Ortolani maneuvers (p = 0.003). CONCLUSIONS:Nerve palsies were associated with more severe DDH at the initiation of Pavlik harness use. Upper and lower-extremity neurological status should be scrutinized at initiation and throughout treatment to assess for nerve palsies. The potential for femoral, gluteal, and brachial plexus palsies should be included in the discussion of risks at the beginning of treatment. Families may be reassured that nerve palsies associated with Pavlik harness can be expected to resolve with a short break from treatment. LEVEL OF EVIDENCE:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Objective: Severe spinal deformity results in restrictive pulmonary disease from thoracic distortions and lung-volume limitations. Though spirometry and body plethysmography are widely accepted tests for pulmonary function tests (PFTs), they are time-consuming and require patient compliance. This study investigates whether surface topographic [surface topography (ST)] measurements of body volume difference (BVD) and torso volume difference between maximum inhale and exhale correlate to values determined on PFTs. Methods: This study included patients with idiopathic scoliosis and thoracic/thoracolumbar curves ≥40 degrees. Patients received ST scans, clinical examinations, and EOS biplanar radiographs on the same day. PFTs were performed within 3 months of ST/radiographic analysis. Univariate linear regression analysis was used to examine relationships between BVD, PFT values, and mean curves. Results: Sixteen patients (14.6 ± 2.2 y, 69% females) with idiopathic scoliosis and mean thoracic/thoracolumbar curves of 62 degrees ± 15˚ degrees (45 degrees to 93 degrees) were assessed. BVD displayed statistically high-positive positive correlations with forced vital capacity ( R = 0.863, P < 0.0001), forced expiratory volume in 1 second ( R = 0.870, P < 0.001), vital capacity ( R = 0.802, P < 0.0001), and TLC ( R = 0.831, P < 0.0001. Torso volume difference showed similarly high positive correlations to forced vital capacity, forced expiratory volume in 1 second, vital capacity, and TLC, but not residual volume. No correlations emerged between the mean thoracic/thoracolumbar curve and BVD or PFT values. Conclusion: This study strongly endorses further investigation into ST scanning as an alternative to traditional PFTs for assessing pulmonary volumes. The noncontact and noninvasive nature of ST scanning presents a valuable alternative method for analyzing thoracic volume, particularly beneficial for patients unable to cooperate with standard PFTs. Level of Evidence: Level II—prognostic.

STUDY DESIGN:Retrospective case series.OBJECTIVE:To characterize the change in angle of trunk rotation (ATR), axial vertebral rotation (AVR), and body surface rotation (BSR) in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF) with en-bloc derotation across multiple postoperative visits.SUMMARY OF BACKGROUND DATA:Previous research has documented ATR, AVR, and BSR correction for AIS patients after surgery. However, there is a lack of evidence on the sustainability of this correction over time.METHODS:This was a retrospective study from a single-center prospective surface topographic registry of patients with AIS, age 11-20 at time of surgery, who underwent PSF with en-bloc derotation. Patients with previous spine surgery were excluded. ATR was measured with a scoliometer, AVR through EOS radiographic imaging, and BSR via surface topographic scanning, Data collection occurred at: preoperative, six-week, three-month, six-month, one-year, and two-year postoperative visits. BSR and AVR were tracked at the preoperative apical vertebral level, and the level with maximum deformity, at each respective timepoint. Generalized estimating equations models were used for statistical analysis. Covariates included age, sex, and body mass index.RESULTS:49 patients (73.4% female, mean age 14.6±2.2 years, mean preoperative coronal curve angle 57.9°±8.5, and 67% major thoracic) were evaluated. ATR correction was significantly improved at all postoperative timepoints and there was no significant loss of correction. AVR Max and AVR Apex were significantly improved at all timepoints but there was a significant loss of correction for AVR Apex between the six-week and one-year visit (P=0.032). BSR Max achieved significant improvement at the three-month visit. BSR Apex was significantly improved at the three-month and one-year visit.CONCLUSION:ATR and AVR demonstrated significant axial plane correction at two-years postoperative in patients undergoing PSF for AIS. BSR did not maintain significant improvement by the two-year visit.

BACKGROUND CONTEXT Historically, pedicle screw accuracy measurements have relied on computed tomography (CT) and expert visual assessment of the position of pedicle screws relative to preoperative plans. Proper pedicle screw placement is necessary to avoid additional complications and cost of revision procedures. PURPOSE To determine accuracy and precision of pedicle screw insertion via a novel computer vision algorithm utilizing preoperative and postoperative CT scans. STUDY DESIGN/SETTING Cadaveric controlled lab study. PATIENT SAMPLE Three adult cadaveric specimens. OUTCOME MEASURES The difference in tip, tail, and mid-pedicle screw distance (in millimeters), mean error, variance, and mean absolute error between preoperative plan and postoperative CT. METHODS Screw placement was planned in generic planning and segmentation software using standard criteria for screw planning. Two surgeons experienced in robotic workflow performed bilateral T2-L4 instrumentation using robotic-assisted navigation. Postoperative CT scans of the entire vertebral column were obtained. Automated segmentation and computer vision techniques were employed to align each postoperative vertebra with its preoperative counterpart and then compare positions along all three axes in an automated fashion. The mid-pedicle position in the anterior-posterior plane was not reported as it is not a measurable parameter. Mean error (ME), mean absolute error (MAE), and variance were calculated. Systematic error, precision, and accuracy were defined as ME, 2 standard deviations, and MAE, respectively. RESULTS Eighty-eight pedicle screws were placed. The computer algorithm showed that robotic-assisted pedicle screw placement was both accurate and precise. This study demonstrates robotic assisted pedicle screws can be placed with submillimeter accuracy in the coronal plane. Furthermore, the tip measurements showed greater precision than the tail measurements. Figure 1 shows both the numerical values and a visual representation of accuracy and precision. CONCLUSIONS This study introduces automated algorithms for determining accuracy and precision of planned pedicle screws. Our accuracy outcomes are comparable or superior to recent data from robotic-assisted in vivo studies in adult patients, as well as prior cadaver studies. This algorithmic computerized workflow establishes a standardized protocol for assessment of pedicle screw placement accuracy and precision, and provides baseline accuracy and precision for both cadaveric and in vivo comparison. FDA Device/Drug Status Medtronic Mazor X Stealth (Approved for this indication)