Adolescent idiopathic scoliosis (AIS) is the most common form of spinal deformity affecting millions of adolescents worldwide, but it lacks a defined theory of etiopathogenesis. Five multi-generation AIS families and 843 sporadic cases were identified, and along with 3219 controls, underwent genetic analyses including linkage analysis, genome sequencing, and targeted sequencing to identify pathogenic variants. Paraspinal muscle sEMG tests were performed on familial cases. Additionally, 858 patients from two additional AIS cohorts in China and US were used for validation. After identifying disease-associated variants, cellular mechanisms were studied and zebrafish models were generated to understand the underlying etiology of the spinal curvature and to test candidate treatments. Disease-causing and predisposing variants of SLC6A9 in multiple families and many sporadic cases were identified via genetic analyses. SLC6A9 variants affected subcellular localization and stability of GLYT1, leading to reduced glycine uptake activity in cells. Slc6a9 mutant zebrafish exhibited discoordination of spinal neural activities and pronounced spinal curvatures which resembles the human patients carrying the SLC6A9 pathogenic variant. Administration of a glycine receptor antagonist or a clinically used glycine neutralizer sodium benzoate partially rescued the phenotype (scoliosis phenotype dropped from 70.2% to 30.3%). Aberrant EMG bursts were found in SLC6A9 pathogenic variants suggesting an impairment of paraspinal muscle balance control. Genetic variants affecting glycine transportation are strong causal risk factors of AIS. Results from patients and animal models suggest a neuropathic origin for “idiopathic” scoliosis, involving the dysfunction of CPGs, potentially a common cause of AIS.

There is ongoing debate regarding whether the component exchange leads to decreased revision rates in debridement antibiotic implant retention (DAIR) for persistant wound discharge following primary hip arthroplasty. This study aims to compare the outcomes of DAIR procedures with and without the exchange of modular components in patients with persistent wound discharge in the early postoperative period following primary total hip arthroplasty (THA).

Methods

This retrospective study involved 18,233 consecutive patients who underwent primary THA at a tertiary center from January 2007 to December 2022. The comparison focused on patients with persistent wound discharge within 30 days of primary THA undergoing debridement and implant retention (DAIR) with modular component exchange versus those without. The primary outcome assessed was any-cause revision surgery, while secondary outcomes involved identifying risk factors for poor outcomes. Statistical analysis included Student t-test, chi-square, and logistic regression.

Results

110 patients underwent DAIR of which 37 had modular component exchange, while 73 did not. The average days to wash out post-primary surgery were 18.4 +/- 5.6 days. Revision surgery rates were 16.2% (6/37) for DAIR with modular exchange and 15.1% (11/73) for DAIR without modular exchange (Odds ratio: 1.09; 95% CI 0.36-3.22). Factors positively correlated with revision risk were CRP on readmission and polymicrobial infection, while age, sex, BMI, and Charlton comorbidity index showed no correlation.

Conclusions:

The exchange of modular components did not result in improved revision rates among patients undergoing DAIR for persistent wound discharge in the early postoperative period following total hip arthroplasty.

Introduction: This study examines incidence and predictors of nerve injury in pediatric acute Monteggia fracture-dislocations. Methods: We retrospectively reviewed pediatric patients (≤ 18
years) with acute Monteggia fractures treated operatively from 2011-2021. Included fractures met Bado's criteria or were Monteggia-equivalent, including olecranon fractures, isolated radial dislocations with ulnar plastic deformation, and radial neck fractures with dislocation and ulnar fracture. Exclusions were chronic fractures (≥30 days), malunions, or cases without imaging. Logistic regression adjusted for fracture heterogeneity and age. Results: Of 170 pediatric patients (average age: 6.5 years), 19.4% had fracture-related nerve injuries: 17 posterior
interosseous nerve (PIN), 9 anterior interosseous nerve (AIN), and 8 other nerve injuries. Significant predictors for overall nerve injury include age over 8 (odds ratio [OR] 4.8, 95%
confidence interval [CI] 2.0-11.4, P=0.001), ulnar comminution (OR 2.9, 95% CI 1.2-7.0, P=0.019), lateral dislocation (OR 2.8, 95% CI 1.1-7.5, P=0.035), and open fracture (OR 3.0,
95% CI 1.0-8.7, P=0.043). Subgroup analysis found lateral dislocation (OR 5.3, 95% CI 1.48-18.6, P=0.010) and ulnar comminution (OR 4.6, 95% CI 1.4-14.5, P=0.010) predicted PIN injury in multivariable analysis. Univariable analysis was feasible for AIN injury and found that open fracture (OR 7.5, 95% CI 1.9-29.8, P=0.005) and ulnar diaphyseal fracture (OR 10.9, 95% CI
1.3-89.5, P=0.026) increased risk. Conclusion: Key predictors of nerve injury in pediatric Monteggia fractures are age over 8, ulnar comminution, lateral dislocation, and open fracture.
Clinicians should consider PIN injury with lateral dislocation or ulnar comminution and AIN injury after open fracture or ulnar shaft fracture.

Objective To evaluate the impact of bone-implant gap size on the interfacial osseointegration of cervical disc arthroplasty (CDA) in a rabbit animal model.
Methods A cylindrical (8 mm in diameter with different depth) calvarial bone-implant gap model was established to assess the impact of bone-implant gap size on interfacial osseointegration. A series of round-plate implants with different teeth depth (0.5 mm, 1.0 mm, 1.5 mm and 2.0 mm) was specifically designed. A total of 48 New Zealand white rabbits were randomly categorized into four groups by the implants they received (0.5 mm: group A, 1.0 mm: group B, 1.5 mm: group C, 2.0 mm: group D). At 4th and 12th week after surgery, animals were sacrificed. Micro-CT, acid fuchsin and methylene blue staining and hematoxylin and eosin (HE) staining were conducted.
Results At 4th week and 12th week after surgery, both micro-CT and HE staining showed more new bone formation and larger bone coverage in group A and group B than that in group C and group D. At 12th week, the bone biometric parameters were significantly superior in group C when compared with group D (p<0.05). At 12th week, hard tissue slicing demonstrated larger portion of direct contact of new bone to the HA coating in group A and group B.
Conclusions Bone-implant gap size larger than 1.0 mm negatively affected bone-implant osseointegration between compact bone and HA coated implant surface.

Introduction:

Achilles tendon ruptures are among the most common and debilitating tendon injuries, particularly affecting athletes and active individuals. The decision to pursue operative repair is guided by the goal of optimizing functional outcomes, reducing the risk of re-rupture, and facilitating a quicker return to pre-injury levels of activity.

Material and Methods:

This retrospective cohort study compares the results between the modified SpeedBridge technique and traditional direct repair for Achilles tendon rupture. reviewed the outcomes of 100 patients treated for Achilles tendon rupture, with 64 cases managed with the SpeedBridge technique and 36 cases treated with direct repair. Patient selection was in alignment with the SMART programme's operative intervention criteria and both groups had the same rehabilitation program, Primary outcomes measured included functional recovery, as determined by the Manchester Foot and Ankle Score, and the timeline for return to physical activity, monitored over a 12-month post-treatment period.

Results

Analysis revealed that patients treated with the SpeedBridge technique, following the SMART programme's guidelines, demonstrated significantly faster recovery and earlier return to physical activities than those undergoing direct repair. Additionally, the SpeedBridge cohort reported higher Manchester Foot and Ankle Scores, indicating a better functional outcome.

Objective: This multicenter, randomized, and controlled trial aimed to compare the outcomes of patients with joint surface lesions (JSLs), with or without concurrent OA, who were treated with an aragonite-based osteochondral implant (Agili-C™, CartiHeal Ltd, Israel) to those treated with arthroscopic debridement/microfractures.
Methods and Materials: A total of 251 subjects meeting specific criteria were enrolled across 26 medical centers. Subjects were randomized in a 2:1 ratio to receive either the implant or debridement/microfracture. Evaluations were conducted at 6, 12, 18, and 24 months using various questionnaires and MRI assessments to measure outcomes.
Results: Both groups had similar demographic characteristics and baseline values. The implant group consistently showed statistically superior outcomes compared to the control group at all follow-up visits. The improvement in the implant group, especially in terms of mean KOOS improvement, was significantly larger than in the control group. Additionally, a higher responder rate and greater defect fill on MRI were observed in the implant group. The failure rate was also lower in the implant group compared to the control group.
Conclusion: The aragonite-based implant demonstrated superior clinical and radiographic outcomes compared to debridement/microfractures at the 24-month evaluation.
Keywords: Agili-C™; aragonite; scaffold; joint surface lesions; microfractures; debridement; RCT

Background
Mechanical Alignment (MA) in total knee arthroplasty aims for perpendicular alignment of components to the limb's mechanical axis. However, individual knee anatomy variations raise concerns about its universal applicability. In contrast, Kinematic Alignment (KA) aligns implants with the knee's pre-arthritic anatomy, optimizing function and satisfaction. There have not been any gait studies in the Indian population, and the literature lacks comparative data between MA and KA techniques. Knee adduction moment (KAM) has been recognized as a good clinical surrogate for medial tibiofemoral joint loading and is associated with implant durability after TKA

Purpose
This RCT aims to compare gait parameters in Kinematic and Mechanical alignment.

Methods
A prospective RCT with 27 patients (54 knees) undergoing bilateral simultaneous TKA randomized one knee to KA and the other to MA. Gait analysis was done postoperatively during the 1-year follow-up period using external infrared sensors-based motion capture technology

Results
Comparing gait parameters, basic parameters like swing and stance phase durations showed no significant differences between KA and MA limbs. Knee Adduction Moment (KAM) was significantly lower in the KA limb compared to the MA limb despite increased proximal tibia varus in the KA group. No significant difference in peak Knee Flexion Moment (KFM) was noted between the two groups.

Conclusion
A smaller Knee Adduction moment indicates lesser medial tibiofemoral loading in the KA group, possibly leading to lesser implant wear and increased implant durability in longer follow-up. These warrant larger Multicenter RCTs with longer follow-ups for deeper insights.

Introduction
Tibial stems in total knee arthroplasty (TKA) have been postulated to enhance fixation and decrease rates of aseptic tibial loosening (ATL) in obese patients. Tibial stems are commonly implanted in TKA placed using mechanical alignment (MA) rather than kinematic alignment (KA). The purpose of this study was to determine the influence of a tibial stem on ATL rates as a function of alignment strategy. We hypothesized that obese patients undergoing TKA with MA with stem would have lower ATL rates than patients undergoing KA without stem.

Methods
We reviewed patient records with body mass index (BMI) greater than 35.0 kg/m^2 who underwent primary, cemented TKA for osteoarthritis from 2013 to 2018 with minimum 12 months follow-up. Statistics included logistic regression with alpha=0.05. The post-hoc power analysis indicated our power is 80% using a difference of 11% in ATL rates.

Results
A total of 176 patients were included: 111 in the MA group and 65 in the KA group. 64 (58%) and 12 (18%) of the MA and KA groups had tibial stems, respectively. Mean BMI was 40.4 kg/m^2 (range, 35.0 to 55.9) and average follow-up was 3.9 years (range, 1 – 10 years). No patients with stems whereas four MA and four KA without stems experienced ATL. Neither alignment type (p = 0.98) nor stem presence (p=0.99) was associated with ATL.

Conclusion
In class 2 and 3 obesity, the risk of developing ATL is not significantly associated with alignment strategy used nor the presence of a tibial stem.