Objective:To investigate the risk factors for recurrence after modified Chevron osteotomy for hallux valgus.Methods:A total of 86 patients (102 feet) with hallux valgus who underwent modified Chevron operation in Beijing Jishuitan Hospital from December 2018 to February 2021 were retrospectively analyzed. There were 12 males (14 feet) and 74 females (88 feet), aged 50±15 years (range, 18-74 years). There were 36 cases on the right side, 34 on the left side, and 16 on the bilateral side. 4 feet were treated with Chevron osteotomy, 74 feet with modified McBride's osteotomy, 61 feet with Weil osteotomy, 24 feet with Akin osteotomy, and 23 feet with gastrocnemius aponeurotic release. At the last follow-up, hallux valgus angle (HVA) ≤15° was defined as the non-recurrence group after hallux valgus operation, and HVA>15° was defined as the recurrence group after hallux valgus operation. Compare the age, gender, preoperative HVA, the first and second intermetatarsal angles (IMA) before and after operation, the metatarsus adductus angles (MAA) before and after operation, the Meary angles before and after operation, the distal metatarsal articular angles (DMAA) before and after operation, the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot scores before and after operation, and the rotation of the first metatarsal head between the two groups of patients. Include the indicators with statistically significant differences in the binary variable logistic regression analysis to screen for the risk factors of recurrence after modified Chevron operation for hallux valgus.Results:All patients successfully completed the operation and were followed up for 30.3±16.4 months (range, 12-52 months). Postoperative recurrence occurred in 21 feet, and the recurrence rate was 20.6% (21/102). The HVA at the last follow-up was 8.48°±4.52° in the non-recurrence group and 20.68°±3.61° in the recurrence group. In the non-recurrence group, the AOFAS ankle-hindfoot score increased from 60.31±16.62 points preoperatively to 86.89±12.79 points postoperatively ( t=-13.644, P<0.001). In the recurrent group, the AOFAS ankle-hindfoot score increased from 61.71±15.68 points preoperatively to 84.33±18.84 points postoperatively ( t=-6.082, P<0.001). The proportion of patients with preoperative Meary angle> 4° in the non-recurrence group was 52% (10/21), which was lower than 79% (64/81) in the recurrence group, and the difference was statistically significant (χ 2=6.077, P=0.014). The proportion of patients with square type of metatarsal rotation (type A) in the recurrence group was 58%(47/81), which was higher than 33%(7/21) in the non-recurrence group, and the difference was statistically significant (χ 2=4.081, P=0.043). There was no significant difference in gender, age, preoperative HVA, pre- and post-operative IMA, pre- and post-operative DMAA, pre- and post-operative MAA, or preoperative metatarsal rotation type between the two groups ( P>0.05). The results of the logistic regression analysis showed that a preoperative Meary angle ≤ 4° ( OR=3.299, P=0.024) and a non-type A metatarsal rotation pattern after operation ( OR=4.183, P=0.041) were independent risk factors for recurrence after modified Chevron operation for hallux valgus. Conclusion:Hallux valgus patients with a preoperative Meary angle ≤4° and non-type A metatarsal rotation after operation have an increased risk of recurrence following modified Chevron operation.

A rare case of Langerhans cell histiocytosis (LCH) combined with Erdheim-Chester disease (ECD) in the tibia is presented. A 55-year-old female patient experienced a six-month history of left lower leg pain of unknown origin, which progressively worsened over the past month and was accompanied by restricted mobility. Radiographic imaging revealed patchy, mixed-density shadows within the medullary cavities of the middle and lower segments of both tibiae and fibulae. Magnetic resonance imaging (MRI) showed extensive abnormal signal areas in the lower segments of the left tibia and fibula, as well as in the left talus and calcaneus. Positron emission tomography-computed tomography (PET-CT) demonstrated significantly increased diffuse radioactive uptake in the middle and lower segments of both femora, the upper and lower segments of the tibiae, the bilateral talus, the distal radius, and symmetrical uptake in the bilateral elbow joints. Additionally, mild radionuclide uptake was observed in the bilateral clavicles and the upper segment of the right femur. The initial diagnosis suggested a space-occupying lesion in the tibia with a suspicion of ECD. Histopathological examination of a biopsy from the left tibial lesion indicated a histiocytic proliferative disorder. After a multidisciplinary consultation, a definitive diagnosis of LCH with fibrous hyperplasia and extensive infiltration of foam cells, along with scattered multinucleated giant cells, was established. The presence of the BRAFV600E mutation further supported the concurrent diagnosis of ECD. Subcutaneous interferon-α therapy was initiated. Two years later, pulmonary lesions were identified. Computed tomography (CT) revealed multiple round nodules in both lungs, chronic inflammatory changes, and fibrous cord-like lesions. Consequently, interferon treatment was discontinued, and oral vemurafenib was administered. After three years of follow-up, chest CT demonstrated a significant reduction in chronic inflammatory lesions and fibrous cords, along with a decrease in nodule size. Currently, after four years of continuous follow-up, the patient remains in stable condition, experiences no significant discomfort, and continues to receive vemurafenib maintenance therapy. A review of the literature suggests that the co-occurrence of LCH and ECD is rare, often leading to misdiagnosis or delayed diagnosis. While no standardized treatment protocol exists, patients harboring the BRAFV600E mutation may benefit from BRAF inhibitors such as vemurafenib.

Hallux valgus is one of the common foot deformities. Osteotomy can effectively correct hallux valgus and relieve pain. In recent years, minimally invasive osteotomy for hallux valgus has attracted the attention of doctors and patients due to its perioperative advantages (small incision and fast recovery) and effectiveness. Compared with the first and second generation minimally invasive osteotomy techniques for hallux valgus, the third generation of minimally invasive techniques has the advantages of easy osteotomy, strong correction ability, and stable internal fixation, so it has been rapidly promoted at home and abroad. Although it has been reported that the third generation of minimally invasive techniques has satisfactory therapeutic effects, complications such as nerve damage and metastatic metatarsalgia are reported as well. Therefore, there are many key points and skills in the surgery that deserve attention. A high-torque power system, portable intraoperative fluoroscopy equipment, and appropriate reduction and internal fixation instruments are all prerequisites for the technique. The minimally invasive osteotomy is V-shaped or transverse (some surgeons define the transverse osteotomy as the fourth-generation technique). The direction of osteotomy is recommended to be perpendicular to the second metatarsal. Three-dimensional orthopedics should be paid attention to when extrapolating metatarsal heads such as crowbars, "in-out-in" method can be used to avoid the dorsomedial cutaneous nerve when internal fixation and nail placement, the continuity of the contralateral cortex should be preserved as much as possible when Akin osteotomy is used, the release of the lateral adductor muscle and the tightening of the medial joint capsule are helpful to further achieve soft tissue balance, and good postoperative bandaging and analgesia are also important links to ensure the treatment effect. In summary, it requires a certain learning curve and operational experience to master the minimally invasive technique. Performing surgery according to indications, doing a good job of preoperative evaluation and perioperative management are conducive to obtaining a good prognosis.

This article reviews the progress of clinical research on abnormal sounds after ceramic-on-ceramic total hip arthroplasty, with a focus on analyzing the differences between the third-generation and fourth-generation ceramic prostheses. Abnormal sounds generally refer to high-pitched audible sounds (such as creaking, clicking, etc.) during hip joint movement after surgery, which are considered possible precursors to prosthesis fragmentation (for example, patients with abnormal sounds have more ceramic particles in the joint fluid, and some are accompanied by prosthesis fragmentation). The fundamental frequency of abnormal sounds in the third-generation ceramic prostheses ranges from 400 to 7 500 Hz (approximately 1 500 Hz in males and 2 500 Hz in females), while the acoustic characteristics of the fourth-generation ones remain unclear. The reported occurrence time of abnormal sounds varies significantly among different studies, with an average of 6.4 to 40 months after surgery. This variation may be influenced by patient characteristics, surgical technique, and prosthesis type. Abnormal sounds are considered a possible early indicator of prosthesis fragmentation; for instance, higher concentrations of ceramic particles have been detected in the synovial fluid of affected patients, and some cases have been accompanied by prosthesis fracture. The incidence of abnormal sounds with the fourth-generation prostheses ranges from 3.8% to 46.6% (with a follow-up period exceeding 10 years), while the third-generation shows rates of 0% to 19.7% with no difference between the two generations. Although the fourth-generation prostheses are superior to the third-generation in material toughness (flexural strength>1 380 MPa) and hardness, they still fail to solve the problem of abnormal sounds, and the incidence may increase with the extension of the follow-up time (for example, in some studies, the incidence at 10-year follow-up is higher than that at 5-year follow-up). Abnormal sounds are mostly associated with movements such as extreme flexion (e.g., squatting) and walking. Different sound properties (such as friction sound) correspond to specific inducing movements and locations, among which friction sound requires vigilance against the risk of prosthesis fragmentation. The risk factors include patient-related factors (height, weight, activity level, etc.), surgical factors (prosthesis position angle), and prosthesis-related factors (design, diameter, neck length, etc.). Proposed mechanisms include abnormal edge loading, stripe wear, femoral neck impingement, wear particle generation, and prosthesis mismatch. Adverse outcomes include decreased patient satisfaction with life, revision surgery (with an incidence of 0.2% to 4.65%), and prosthesis fragmentation. Currently, there are still controversies in research. Future studies need to focus on special patient groups, surgical techniques (such as robot-assisted surgery), and the optimization of prosthesis materials and designs (such as gradient structures and surface coatings) to reduce the incidence of abnormal sounds.

Nanomaterials can be used in drug delivery systems to enhance drug targeting and efficacy, and reduce adverse reactions. At the same time, they can also be used in tissue engineering and regenerative medicine to promote bone tissue repair and regeneration. Nanozymes are special nanomaterials with the catalytic activity of biological enzymes, which can mediate efficient biochemical reactions and provide a new strategy for the diagnosis and treatment of orthopaedic diseases. In the treatment of tendon-related diseases, the enzymatic nanohybrid encapsulated by extracellular vesicles can effectively mimic catalase to remove reactive oxygen species, continuously release zinc ions, and induce immune regulation through extracellular vesicles. It can significantly promote functional recovery and matrix reconstruction, restore tendon morphology, and inhibit scar formation and adhesion around the tendon. In the treatment of bone and joint diseases, photothermal nanozymes with bionic characteristics can generate thermal energy under near-infrared radiation, enhance joint lubrication performance, reduce cartilage wear in early osteoarthritis, effectively remove reactive oxygen species and reactive nitrogen species, increase the production of hyaluronic acid inside and outside the cells, and help to restore the lubrication and function of articular cartilage. Hollow Prussian blue nanoenzyme prepared by template-free hydrothermal synthesis can inhibit osteoclast formation and bone resorption, inhibit intracellular reactive oxygen species production and mitogen-activated protein kinase and nuclear factor kappa-B signaling pathways, thereby improving osteoporosis. In the treatment of spinal diseases, Prussian blue nanozymes can not only remove excessive reactive oxygen species, maintain the normal Redox level of nucleus pulposus cells, but also escape lysosomal phagocytosis, achieve more effective mitochondrial targeting, and effectively alleviate intervertebral disc degeneration.

Objective:To explore the advantages of robotic-arm assisted total hip arthroplasty (rTHA) in acetabular component positioning and lower limb length assessment in patients with severe pelvic coronal tilt.Methods:A retrospective analysis was conducted on the data of 122 patients with unilateral end-stage hip disease and coronal pelvic tilt angle >3° who underwent total hip arthroplasty (THA) at the First Medical Center of PLA General Hospital from June 2022 to December 2023. Among them, 44 patients underwent rTHA, and 78 underwent manual THA (mTHA). The rTHA group included 18 males and 26 females, with an average age of 60.5±9.3 years; the mTHA group included 41 males and 37 females, with an average age of 58.5±8.4 years. Compare the differences in the anteversion angle, abduction angle, pelvic tilt angle, leg length discrepancy (LLD) of the acetabular prosthesis, and the proportions of patients with LLD>0.5 cm and >1 cm between the two groups of patients after surgery. Calculate the proportion of outlier rates of acetabular abduction angle (<30° or >45°), and proportions within Callanan's safe zone. The early efficacy of the hip joint was evaluated by using the modified Harris score and joint range of motion.Results:All patients were followed up for 6 to 12 months, with an average of 8 months. All the surgical incisions of the patients achieved primary healing. Postoperative comparisons showed no statistically significant differences in acetabular abduction angle (39.5°±3.3° vs. 38.4°±7.3°) or anteversion angle (20.7°±1.6° vs. 19.7°±1.6°) between rTHA and mTHA groups ( P>0.05). However, pelvic tilt angle [2.5° (1.1°, 3.6°) vs. 3.5° (2.3°, 5.9°)] showed a statistically significant difference ( U=4.371, P=0.008). The rTHA group exhibited smaller absolute LLD [0.2 (0.1, 0.4) cm vs. 0.5 (0.2, 0.5) cm] and lower proportions of LLD >0.5 cm [14% (6/44) vs. 49% (38/78)] and >1 cm [2% (1/44) vs. 18% (14/78)], with statistical significance ( P<0.05). The rTHA group had a lower outlier rate for acetabular abduction angle (<30°or >45°) compared to the mTHA group [2% (1/44) vs. 33% (26/78)], with statistical significance (χ 2=10.388, P<0.001). Taking the Callanan safety zone as the standard, the proportion of acetabular cups within the safe zone was significantly higher in the rTHA group (98%, 43/44) compared to the mTHA group (67%, 52/78), with a statistically significant difference (χ 2=13.998, P<0.001). The modified Harris score and hip joint range of motion in the mTHA group increased from 47.6±6.6 points and 83° (73°, 88°) before the operation to 83.5±11.2 points and 118° (110°, 122°) at the last follow-up, respectively. The rTHA group increased from 46.5±9.2 points and 79° (71°, 90°) before the operation to 85.0±12.5 points and 124° (116°, 130°) at the last follow-up. The differences in the modified Harris score and hip joint range of motion between the two groups before the operation and at the last follow-up were statistically significant ( P<0.05). However, there was no statistically significant difference between the groups at the last follow-up ( P>0.05). No THA-related complications occurred during follow-up period. Conclusion:For patients with end-stage hip joint diseases with coronal tilt exceeding 3°, robotic-assisted technology significantly improves the accuracy of acetabular component placement during THA and offers better control of postoperative LLD.

Objective:To explore the efficacy and safety of one-hole split endoscope (OSE) minimally invasive surgery for the treatment of single-segment thoracic ossification of the ligamentum flavum (TOLF).Methods:This retrospective non-randomized controlled study included 41 patients with single-segment TOLF who underwent surgery at Qilu Hospital of Shandong University between July 2019 and July 2023. Patients were divided into two groups: the OSE group (19 cases) treated with one-hole split endoscope minimally invasive surgery and the open group (22 cases) treated with traditional laminectomy and pedicle screw fixation. There were no significant differences between the two groups on gender, age, disease duration, affected segment, presence or absence of dural ossification, and residual cross-sectional vertebral canal area on CT ( P>0.05). Additionally, perioperative surgical time, estimated blood loss (EBL), incision length, hospital stay duration, hospitalization costs and follow-up duration were compared. The Japanese Orthopaedic Association (JOA) score and Oswestry Disability Index (ODI) were compared preoperatively and at the last follow-up. Complications were also recorded. Results:All patients successfully completed the surgery with no significant differences at the last follow-up ( P>0.05). Compared with the open group, the OSE group had a significantly shorter operative time (133.1±16.8 vs. 160.5±22.6 min), lower EBL (91.2±15.0 vs. 192.5±43.8 ml), shorter incision length (2.6±0.5 vs. 7.9±1.9 cm), reduced hospital stay (3.9±0.8 vs. 5.6±0.8 days), and lower hospitalization costs (34,874.9±4,568.6 vs. 53,162.3±9,815.6 yuan) (all P<0.05). AAt the final follow-up, JOA scores (8.5±0.8 vs. 8.6±1.2) and ODI values (16.7%±2.1% vs. 17.7%±4.4%) showed no significant differences between the OSE and open groups ( P>0.05). During the perioperative period and follow-up, complications occurred in 2 patients in the OSE group (1 cerebrospinal fluid leak, 1 poor wound healing) and in 8 patients in the open group (5 cerebrospinal fluid leaks, 1 neurological deterioration, 2 poor wound healing). Conclusion:OSE minimally invasive surgery is an effective treatment for single-segment thoracic ossification of the ligamentum flavum. Compared with open surgery, it provides advantages such as minimal invasiveness and fewer complications.

Objective:To investigate the clinical significance and inducing factors of abnormal intraoperative neurophysiological monitoring (IONM) signals during surgery for cervical degenerative diseases.Methods:A retrospective analysis was performed on 586 patients who underwent cervical degenerative disease surgery with IONM at the Department of Orthopedics, The First Affiliated Hospital of Soochow University, from April 2015 to April 2024. Surgical approaches included 380 anterior spinal canal decompression and fusion procedures, 154 posterior spinal canal decompression and fusion procedures (including single-door laminoplasty, total laminectomy, and hemilaminectomy), and 52 combined anterior-posterior surgeries. The multimodal IONM protocol employed transcranial electrical stimulation motor evoked potentials (TES-MEP) and cortical somatosensory evoked potentials (CSEP), combined with electromyography (EMG). Bilateral deltoid muscles, thenar/hypothenar muscles and abductor hallucis muscles were monitored in all patients. Intraoperative MEP, SEP, and EMG results were recorded to analyze the causes of abnormal signals, intraoperative response strategies, and postoperative neurological function and outcomes. Fourfold table chi-square tests were used to analyze factors possibly associated with IONM alerts.Results:Among the 586 cervical surgeries, 17 cases (2.9%) exhibited abnormal IONM signals. These included 4 cases of anterior cervical discectomy and fusion (ACDF), 4 cases of anterior cervical corpectomy and fusion (ACCF), and 2 cases of combined anterior-posterior surgeries for cervical spondylotic myelopathy; and 5 posterior surgeries and 2 anterior ACCF procedures for ossification of the posterior longitudinal ligament (OPLL). The rate of abnormal IONM signals was significantly higher in patients with maximum spinal cord compression (MSCC)>60% (5.8%, 12/208) than in those with MSCC≤60% (χ 2=9.417, P=0.002); in patients with intraoperative hypotension during posterior surgery (mean arterial pressure reduction>20% from baseline, cumulative duration>20 min), the abnormal IONM rate was 22.2% (6/27), which was significantly higher than that in patients without intraoperative hypotension (χ 2=33.542, P<0.001); in patients who underwent calcified tissue removal during anterior surgery, the abnormal IONM rate was 9.3% (5/54), which was significantly higher than that in patients without calcified tissue removal (χ 2=13.162, P=0.003). Thus, MSCC>60%, intraoperative hypotension during posterior surgery, and calcified tissue removal during anterior surgery may be inducing factors for abnormal IONM signals. Among the 17 patients with monitoring abnormalities, 8 cases showed no significant improvement after corresponding intraoperative treatments, and 7 of these 8 cases experienced varying degrees of muscle strength decline and sensory numbness immediately after surgery; 9 cases showed partial or complete recovery of signals, among which 8 cases had no new-onset neurological impairment after surgery, and 1 case developed unilateral upper limb grip strength decline. IONM demonstrated a sensitivity of 0.8750 and specificity of 0.8889. Conclusions:Multimodal IONM can detect electrophysiological abnormalities of spinal cord nerve function during cervical degenerative disease surgery, providing real-time warning of potential nerve damage during the operation. The proportion of abnormal IONM signals is relatively high in cases with MSCC>60%, intraoperative hypotension during posterior cervical surgery, or calcified tissue removal during anterior cervical surgery.

Objective:To analyze the revision strategies for failed atlantoaxial dislocation (AAD) surgery.Methods:A retrospective analysis was conducted on 145 patients who underwent revision surgery for AAD at the General Hospital of Southern Theatre Command of PLA between September 2009 and December 2023. The cohort included 74 males and 71 females, with a mean age of 43±16 years (range, 6-72 years). The initial surgical approaches were: anterior 31 cases, posterior 114 cases. Based on imaging assessments of immediate postoperative reduction and fusion status prior to revision, the cases of failure were classified into reduction-nonfusion type (22 cases), nonreduction-fusion type (31 cases), and nonreduction-nonfusion type (92 cases). Among the nonreduction-nonfusion cases, 39 had initial surgery with internal fixation for reduction, while 53 had initial surgery with simple decompression (posterior arch resection, foramen magnum decompression) without reduction. In the nonreduction-fusion cases, 8 cases had spot fusion and 23 had extensive fusion. Japanese Orthopaedic Association (JOA) scores were compared before and after revision, and complication rates were observed.Results:All patients successfully underwent surgery. The revision approaches included: anterior (anterior fixation and fusion 52 cases, anterior implant removal combined anterior fixation and fusion 4 cases, transoral odontoidectomies 16 cases, anterior implant removal combined transoral odontoidectomy 2 cases), posterior (posterior fixation and fusion 2 cases, posterior implant removal combined posterior fixation and fusion 22 cases), and combined anterior-posterior (posterior implant removal combined anterior fixation and fusion 18 cases, anterior implant removal combined posterior fixation and fusion 25 cases, posterior implant removal combined transoral odontoidectomy 5 cases). Operative time was 254.20±107.63 min (range, 90-660 min), and blood loss was 218.83±172.17 ml (range, 20-800 ml). Except for 3 patients who died due to postoperative complications, all patients were followed up for a duration of 12±11 months (range, 3-60 months). Six patients who failed to achieve bony fusion after the initial revision surgery underwent a second revision due to poor reduction (1 case), infection (1 case), suboptimal implant position (3 cases), and graft nonunion (1 case). All three patients with bony fusion after the initial revision surgery underwent a second revision due to poor reduction. Following the second revision surgery, none of the 9 patients exhibited graft nonunion or spinal cord compression. The 136 successful initial revision cases had a final follow-up JOA score of 14.75±2.00, significantly higher than the preoperative score of 11.93±2.92 ( t=-18.869, P<0.001). Conclusions:Revision surgery for AAD should take into account the immediate postoperative reduction status and fusion status prior to revision. An appropriate revision strategy should be selected to achieve satisfactory reduction and bony fusion.

Objective:To predict mechanical complications (MC) following spinal deformity surgery for adult spine deformity (ASD) using machine learning models, identify key risk factors, and develop a visualizable tool for individualized risk assessment.Methods:Clinical and radiological data from 525 patients with ASD who underwent surgery in our hospital between January 2017 and December 2021 were collected. Patients were randomly assigned to a training set (70%) and a test set (30%) for model development. The cohort included 88 males and 437 females, with a mean age of 42.2±18.1 years. Variables included demographic data, comorbidities, local and systemic radiological parameters, paraspinal muscle fat infiltration (FI), and vertebral bone quality (VBQ) scores. Multiple machine learning algorithms: Random Forest (RF), Gaussian Naive Bayes (GNB), Light GBM, Support Vector Machine (SVM), XGBoost (XGB), and Logistic Regression (LR) were trained and evaluated. Model performance was compared using the receiver operating characteristic curve (ROC) and precision-recall curve (PRC). SHAP (Shapley Additive Explanations) was used to rank risk factors, while LIME (Local Interpretable Model-Agnostic Explanations) was applied to visualize MC risk in individual cases.Results:Of the 525 patients, 135 (25.7%) developed postoperative MC. Among these, 80 (59.3%) experienced proximal junction kyphosis or failure (PJK/PJF), 7 (5.2%) had distal junction kyphosis or failure (DJK/DJF), 28 (20.7%) sustained rod fractures, and 29 (21.5%) showed significant loss of correction. In the validation cohort, the RF model achieved the highest area under the curve (AUC=0.80), followed by GNB (0.77), XGB (0.76), LR (0.74), LightGBM (0.73), and SVM (0.66). The RF model also demonstrated the best PRC value (0.58), highest sensitivity (0.65), and lowest Brier score (0.20). GNB, Light GBM, and LR models achieved the highest accuracy (0.78 each), while LightGBM exhibited the highest specificity (0.93). SHAP analysis identified higher preoperative VBQ scores, larger T 1 pelvic angle (TPA), and higher paraspinal muscle FI as the main risk factors for MC. Based on the RF model, a LIME-based tool was successfully constructed for individualized MC risk estimation. Conclusion:The RF model demonstrated the best overall predictive performance for MC. A machine learning-based prediction model has the potential to provide valuable guidance for surgical decision-making in ASD patients.