Postless hip distraction technique is a novel traction method for hip arthroscopy developed in recent years. Studies have shown that, compared with the traditional post hip distraction technique, it can effectively solve perineal complications, lower the technical threshold of hip arthroscopy, and improve patients' postoperative satisfaction. The standardization of this technique is expected to promote the advancement and popularization of hip arthroscopy. To this end, this Consensus identified 17 questions of the greatest clinical concern that were selected through systematic literature retrieval and evidence quality evaluation, and in combination with clinical practice, using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system and the Reporting Items for Practice Guidelines in Healthcare (RIGHT), and 20 evidence-based medical recommendations were finally formulated, aiming to improve the standardization and scientific nature of the postless hip distraction technique and provide a basis for improving the quality of patient-centered medical services.

Robotic-assisted total knee arthroplasty (raTKA) has seen widespread adoption due to its potential to enhance surgical precision and implant alignment. However, learning curves (LCs) for different robotic platforms remain poorly characterized, complicating training and safe implementation. This systematic review quantified the LC across major raTKA systems, focusing on operative time and the number of cases required to achieve procedural proficiency. A systematic search was conducted on December 16, 2024, across MEDLINE, Embase, Scopus, Web of Science, and CENTRAL, following PRISMA 2020 guidelines (PROSPERO: CRD420251026692). Studies reporting original data on LCs in raTKAs were included. Outcomes were operative time, radiographic alignment, complication rates, and patient-reported outcome measures (PROMs). Due to methodological heterogeneity, meta-analysis was not performed; weighted means were calculated where appropriate. Forty studies were included, comprising 10,533 procedures across nine robotic platforms. Operative time, reported in 38 studies, was the primary LC metric. Cases required to reach proficiency ranged from 2 to 73. Stratified analysis showed proficiency after a mean of 18.4 cases for NAVIO (mean time 81.9 min), 29.5 cases for ROSA (85.5 min), and 34.2 cases for MAKO (82.0 min). Radiographic accuracy and complication rates remained stable throughout. PROMs were underreported and inconsistent, limiting conclusions. The LC for raTKA is platform dependent. Inconsistent reporting of radiographic and safety outcomes, especially with ROSA, limited secondary endpoint analysis. These findings highlight the need for standardized LC definitions and robust comparative studies to guide training, accreditation, and safe clinical integration.

Cervical degenerative disc disease (DDD) occurs when there is deterioration of the intervertebral discs in the cervical spine and can cause extreme pain and disability. Cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) are the two prominent surgical treatment options. There are a few meta-analyses that examine the cost-effectiveness of these two methods. This meta-analysis study seeks to provide a thorough overview of cost-effectiveness and postoperative complications between CDA and ACDF in the treatment of cervical DDD. Publication search was carried out on PubMed and Embase up until March 2025. Comparison studies that included the two treatment methods of interest and reported a cost analysis with complication metrics were included in this meta-analysis. Review Manager 5.4. was utilized for statistical analyses, and a p value ≤ 0.05 was considered statistically significant. Thirteen studies were included. Regarding the cost analysis, there was a significant difference in initial cost in favor of ACDF compared to CDA. As for the outcome metrics, there was a significant difference in reoperation as well as DVT/PE rates in favor of CDA. There was a significant difference in mean operative time in favor of ACDF. No other significant differences were found. ACDF appears to be a cost-effective option, while CDA offers advantages in certain complication metrics. Additional studies investigating the relationship between treatment costs and complications should be completed in order to solidify the superior treatment method for cervical DDD.

Periprosthetic joint infection (PJI) is a devastating complication of joint arthroplasty and is commonly treated with two-stage revision. During two-stage revision, the insertion of a temporary antibiotic-loaded bone cement spacer (ALCS) in infected joints exerts a direct and effective anti-infection effect but may increase the risk of developing acute kidney injury (AKI). This article reviews the latest research progress on AKI after ALCS insertion for PJI treatment and discusses the definition, incidence and outcome of AKI. We focused on analyzing the risk factors for AKI in terms of demographic characteristics, comorbidities, medication history, perioperative management, and types and doses of antibiotics in ALCS patients. The results revealed that advanced age, excessive obesity, a history of diabetes mellitus, a history of hypertension, the use of angiotensin-converting enzyme inhibitor (ACEI) or angiotensin-II receptor blocker (ARB) medications, a history of chronic kidney disease (CKD), preoperative anemia or hypoalbuminemia, the use of nonsteroidal anti-inflammatory drugs (NSAIDs), high intraoperative blood loss, insufficient perioperative rehydration, and transfusions significantly increased the incidence of AKI. The associations between the development of AKI and antibiotic type and dosage in ALCS are still unclear. Further exploration is still necessary to help clinicians identify PJI patients with a high risk of AKI early and improve their prognosis.

Objective: Total knee arthroplasty (TKA) is a well-established intervention for end-stage osteoarthritis (OA), offering substantial pain relief and functional improvement. However, a considerable proportion of patients remain dissatisfied postoperatively due to multifactorial causes. While numerous studies have investigated implant alignment, the sagittal plane alignment has received comparatively less attention, and its clinical relevance remains controversial. This systematic review aims to identify the optimal sagittal alignment (SA) parameters in TKA and to evaluate their impact on clinical outcomes.

Methods: A comprehensive literature search was conducted across four databases (PubMed, the Cochrane Library, Embase, and Web of Science) from their inception to April 1, 2025. Studies focusing on SA after primary TKA were considered. Articles meeting the inclusion and exclusion criteria were subjected to meta-analysis. The SA parameters assessed included tibial slope, posterior condylar offset, tibial and femoral component angles, femoral bowing angle, and tibiofemoral alignment.

Results: The search yielded 1414 articles, after removing duplicates, of which 30 studies met the final inclusion criteria. The review confirmed that SA plays a critical role in postoperative outcomes. Malalignment in the sagittal plane was associated with complications such as instability, hyperextension, and impaired functional recovery. In particular, deviations in tibial slope and femoral bowing angle significantly influenced overall limb alignment and joint mechanics. Although achieving proper SA appears to reduce complications and improve functional outcomes, no universally accepted target values have yet been established.

Conclusion: Based on current evidence, achieving optimal SA during the perioperative period is essential for improving prosthesis longevity and patient satisfaction following primary TKA. Surgeons should pay close attention to SA parameters, and the use of emerging technologies is encouraged to enhance precision in component positioning.Trial Registration: PROSPERO Registration: CRD42023471336

Objective: Implant-associated infections, including periprosthetic joint infection (PJI) and fracture-related infection (FRI), are among the most challenging complications in orthopedic surgery. Although infection timing (early, delayed, late) is recognized as an important factor in surgical success, its impact on patient-reported outcomes and length of hospital stay has rarely been compared between PJI and FRI in a single cohort. This study aimed to examine the association between infection timing and health-related quality of life (HRQoL) as well as length of hospital stay (LOS), and to explore potential differences between PJI and FRI.

Methods: We conducted a retrospective monocentric cohort study of 60 patients with microbiologically confirmed implant-associated infections treated at a German level-I trauma center between January and December 2021, with follow-up performed in 2023. Patients with PJI (n = 29) or FRI (n = 31) were stratified as early (< 3 months), delayed (3–24 months), or late (> 24 months) to enable direct comparison between infection entities. Outcomes included EQ-VAS, EQ-5D-3L mean domain scores, LOS, reinfection, revision surgery, amputation, and in-hospital mortality. Group differences were tested using independent-samples t-tests for continuous variables and chi-square or Fisher's exact tests for categorical variables, with subgroup analyses considered exploratory due to small sample sizes.

Results: Of the 60 patients, 25 had early (PJI n = 11; FRI n = 14), 24 delayed (PJI n = 11; FRI n = 13), and 11 late infections (PJI n = 7; FRI n = 4). EQ-VAS was higher in FRI compared with PJI in early (63.4 ± 17.8, n = 13 vs. 48.3 ± 20.8, n = 9) and delayed infections (66.2 ± 16.8, n = 11 vs. 56.6 ± 13.5, n = 10), while both groups showed markedly lower EQ-VAS values in late infections (FRI: 39.7 ± 25.9, n = 3 vs. PJI: 43.3 ± 23.4, n = 6), which were analyzed descriptively due to very small subgroup sizes. The EQ-5D-3L mean domain score was lower (indicating better health status) in early FRI (1.55 ± 0.33, n = 12) than in early PJI (1.91 ± 0.39, n = 9) in unadjusted analyses. LOS increased with timing, particularly in PJI (early 39.6 ± 26.8 vs. 31.4 ± 29.0 days; delayed 100.6 ± 82.2 vs. 28.2 ± 10.2; p = 0.015). Reinfection rates increased with later timing (early: 6/11 PJI vs. 3/14 FRI; delayed: 8/11 vs. 8/13; late: 5/7 vs. 4/4). Revision surgery was more frequent in early PJI (7/11 vs. 4/14; p = 0.080) but was significantly more common in delayed FRI (12/13 vs. 6/11; p = 0.033). Amputation (≤ 9%) and in-hospital mortality (≤ 15%) were rare and showed no significant differences.

Conclusions: Infection timing was associated with both clinical and patient-reported outcomes in implant-associated infections. Later infections were associated with poorer HRQoL, longer hospital stays, and higher reinfection rates, based on unadjusted analyses, with distinct patterns between PJI and FRI. Early recognition and timely, stage-adapted treatment strategies may help improve patient outcomes.

Purposes: Open elbow arthrolysis (OEA) is a common method for treating post-traumatic elbow stiffness, which may lead to severe bleeding when resecting heterotopic ossification (HO) and fibrous scar tissue. The purpose of this study is to compare the efficacy and safety among three different ways of using tranexamic acid (TXA) in reducing total blood loss and drainage volume in OEA.

Patients and Methods: This was a pilot, double-blinded, randomized controlled trial involving a total of 60 patients of post-traumatic elbow stiffness. Patients in the IV group (n = 20) received TXA intravenously, those in the intra-articular group (n = 20) received TXA topically, and those in the combined group (n = 20) received TXA both intravenously and topically. The primary outcome measure was postoperative blood loss and drainage volume. The secondary outcome measures included elbow function, complications, and secondary surgery.

Results: The postoperative blood loss on the first and third days and the drainage volume on the first day was similar among the three groups (p > 0.05). The total postoperative drainage volume in the IV group was significantly higher than in the combined and intra-articular group, with no significant difference observed between the combined and intra-articular group (534.5 mL vs. 378.0 mL vs. 356.5 mL; p < 0.05). There were no significant differences in elbow flexion-extension and rotation range of motion (ROM) and the Visual Analogue Scale (VAS) and Mayo Elbow Performance Score (MEPS) scores at the follow-up (p > 0.05).

Conclusion: Intravenous, topical, or combined TXA administration showed no significant difference in reducing postoperative blood loss after OEA. However, both combined and topical TXA significantly reduced postoperative drainage volume compared to intravenous administration.

Level of Evidence: Therapeutic Level I.

Objective: Selective thoracolumbar/lumbar fusion is a standard operative strategy for Lenke 5C adolescent idiopathic scoliosis (AIS); however, distal adding-on after this selective fusion remains incompletely characterized, and prior work has largely focused on distal foundation planning rather than proximal coronal construct position. We therefore aimed to compare radiographic and clinical outcomes between patients with and without distal adding-on and to identify radiographic factors associated with distal adding-on, with particular attention to proximal coronal construct position (including postoperative upper instrumented vertebra (UIV) translation) and distal junctional alignment around the lowest instrumented vertebra (LIV) and the first vertebra below the LIV (LIV + 1).

Methods: We retrospectively reviewed 74 patients with Lenke 5C AIS (age 11–18 years) who underwent single-stage posterior selective thoracolumbar/lumbar fusion using an all–pedicle-screw construct, with a minimum of 2 years of radiographic follow-up. Patients were classified according to whether distal adding-on developed during follow-up. Radiographic parameters were assessed preoperatively, immediately postoperatively, and at final follow-up; clinical outcomes were assessed using the Scoliosis Research Society–22 (SRS-22) questionnaire. Univariable screening and multivariable modeling were performed, and multivariable estimates were obtained using Firth penalized logistic regression.

Results: Distal adding-on developed in 18 of 74 patients (24.3%). Age, Risser grade, number of fused segments, lowest instrumented vertebra distribution, and upper instrumented vertebra selection did not differ between groups, whereas sex distribution differed (p = 0.028). The main thoracolumbar/lumbar curve magnitude, sagittal and spinopelvic parameters, and SRS-22 scores were similar between groups at all time points (all p > 0.05). Several junctional coronal parameters differed, including preoperative LIV coronal disc angle (p = 0.029), postoperative LIV + 1 coronal disc angle (p = 0.008), final follow-up LIV + 1 coronal disc angle (p = 0.037), postoperative LIV tilt (p = 0.003), final follow-up LIV tilt (p = 0.048), and UIV translation preoperatively (p = 0.036) and postoperatively (p = 0.001). On univariable logistic regression, postoperative LIV + 1 coronal disc angle (p = 0.011), postoperative LIV + 1 tilt (p = 0.008), and postoperative UIV translation (p = 0.006) were associated with distal adding-on. In multivariable analysis, postoperative UIV translation remained associated with distal adding-on (OR 1.049, 95% CI 1.003–1.102; p = 0.036).

Conclusion: Distal adding-on occurred in approximately one-quarter of patients after selective thoracolumbar/lumbar fusion for Lenke 5C AIS. In addition to distal foundation planning at the LIV, surgeons should consider intraoperative coronal construct positioning, with particular attention to postoperative UIV translation and coronal alignment below LIV + 1.

Level of Evidence: Level III.

Objective: In radiographically stable adult degenerative scoliosis (ADS), unilateral biportal endoscopic (UBE) decompression alone is effective in alleviating symptoms; however, executing adequate decompression without excessive facetectomy in rotated, tortuous anatomy remains challenging. Intraoperative O-arm navigation has the potential to enhance procedural accuracy of UBE decompression. This study compared the clinical outcomes and radiological parameters between O-arm navigation–assisted and conventional fluoroscopy-guided UBE decompression alone in stable ADS.

Methods: This single-center retrospective study included 63 patients with radiographically stable ADS who underwent UBE decompression alone between 2021 and 2023 (navigation, NAV: n = 34; non-navigation, NON-NAV: n = 29). This study presents details about patients' demographics, perioperative parameters, and up to 24 months follow-up outcomes. Primary endpoint was the facet preservation rate (FPR) at 1-month post-operation, quantified by CT-based 3D volumetry. Secondary endpoints included DCSA, lateral recess height/angle, dynamic angulation/slip, patient-reported outcomes (VAS/ODI), and complications. Data were analyzed using independent t-tests, Wilcoxon rank-sum tests, and repeated-measures ANOVA as appropriate.

Results: Operative time and length of stay were slightly shorter in NAV but not statistically different; estimated blood loss was comparable. NAV and NON-NAV groups showed significant improvements in VAS of leg/back pain and ODI at 1 month and last follow-up, without between-group differences. DCSA increased substantially in both groups (~200%–250%); but dispersion was smaller in NAV, indicating more uniform decompression. Structural preservation favored NAV (higher residual lamina-facet volumes). Segmentally, NON-NAV exhibited greater increases in dynamic angulation (8.5° ± 1.2° vs. 6.2° ± 1.4°, p < 0.001) and early slip (2.8 ± 0.8 vs. 1.8 ± 0.8 mm, p < 0.001), although radiographic instability thresholds were not exceeded. Global sagittal and coronal parameters were largely comparable between groups over time.

Conclusion: In stable ADS, O-arm navigation for UBE decompression did not prolong operative time nor increase blood loss, and yielded tighter boundary control of decompression, higher facet preservation, and smaller segmental perturbations, while maintaining equivalent symptomatic improvement. The value of O-arm navigation lies in enabling precise and sufficient decompression while limiting medial facetectomy within stability-preserving margins.

Objective: Cage removal is essential in revision surgery for intervertebral disc space infection (IVDS). The aim of this study is to investigate the effectiveness and safety of using ultrasonic osteotome in segmental resection and removal of cage during revision surgery for IVDS after lumbar fusion.

Method: We retrospectively reviewed 32 patients who underwent revision surgery for IVDS infection after lumbar fusion in our hospital from June 2018 to November 2024. The operation time, blood loss, nerve damage, success rate of removal, infection control, and fusion rate were compared between the traditional whole removal method (n = 15) and the ultrasonic osteotome-based segmental excision method (n = 17).

Results: The average incision length and hospital stay were not significantly different between the two groups (p > 0.05). Nevertheless, the time taken for removing the cage, the success rate of cage removal, intraoperative blood loss, and postoperative drainage were significantly improved in the ultrasonic osteotome group compared with the traditional surgery group (p < 0.05). The assessment of postoperative recovery at 7 days and 1, 3, 12 months postoperation demonstrated significant improvements in VAS and ODI scores compared with the preoperative values in both groups. However, within-group and between-group analyses did not reveal significant differences at these intervals, even up to the 12-month evaluation (p > 0.05). Contrast-enhanced lumbar MRI scans conducted for the 32 patients at 3 months postoperation confirmed successful infection control among all patients. Both groups demonstrated no incidence of dural tears, cerebrospinal fluid leakages, or wound infection. In contrast, incisional fat liquefaction occurred in one and two patients in the ultrasonic osteotome and traditional surgery group, respectively, with all patients exhibiting satisfactory resolution following appropriate wound care. Moreover, a slight deterioration in the extensor muscle strength of the great toe was observed in two patients and an exacerbation of foot dorsum numbness was detected in one patient in the traditional surgery group, with all symptoms fully resolving within the 3-month follow-up period. In contrast, the ultrasonic osteotome group showed no such significant neurological function impairments. At 1-year postoperation, bone fusion was confirmed in both groups via CT reconstructions of the lumbar spine.

Conclusion: Compared with the traditional whole removal method, the ultrasonic osteotome-based segmental excision method has the advantages of shorter and controllable operation time, lower blood loss, higher success rate of removal, and lower risk of nerve damage, making it uniquely valuable in the revision surgery for IVDS infection after lumbar fusion.

Objective: Arthroscopic surgery is recommended for the treatment of hip synovial chondromatosis, as it allows patients to resume daily activities quickly and requires only a short rehabilitation period. Despite its advantages, there is currently no standardized protocol for arthroscopic hip synovectomy, and complete removal of intra-articular loose bodies remains challenging. The objective of this study is to evaluate long-term clinical outcomes of arthroscopic treatment for hip synovial chondromatosis using a standardized protocol based on clock-face-guided, imaging-based lesion localization.

Methods: A consecutive cohort of patients undergoing arthroscopic treatment and diagnosed with synovial chondromatosis between June 2016 and July 2019 was included in the study. All patients underwent preoperative imaging-guided localization of loose bodies followed by arthroscopic removal performed by a single surgeon, with a minimum postoperative follow-up of 30 months. Preoperative and postoperative assessments included standard radiographs (x-ray), three-dimensional computed tomography (3D-CT), magnetic resonance imaging (MRI), intraoperative arthroscopic images, visual analog scale (VAS) for pain, range of motion (ROM), modified Harris Hip Score (mHHS), and International Hip Outcome Tool (iHOT-12). The percentage of patients achieving the minimal clinically important difference (MCID) was calculated to summarize and compare differences in clinical outcomes.

Results: Seventeen patients were enrolled, with a mean postoperative follow-up duration of 71 months. No major complications were observed. Patients achieved weight-bearing ambulation at a mean of 7 days postoperatively and were discharged at a median of 2.5 days (range: 1–3 days). PROs demonstrated significant improvements: VAS for pain decreased from 7.6 to 2.1, mHHS increased from 54.6 preoperatively to 89.4 postoperatively, and iHOT-12 improved from 38.1 to 75.2 (all p < 0.001). At long-term follow-up, all patients met MCID thresholds for both mHHS and iHOT-12 scores.

Conclusion: Arthroscopic treatment using a standardized protocol can result in favorable long-term clinical outcomes.

Objective: There is no consensus on the age restriction for total ankle arthroplasty (TAA) patients. The aim of our study was to analyze the clinical function, radiographic outcomes, patient satisfaction, and complications between patients under 50 years old and those over 65 years old who underwent TAA with the INBONE II prosthesis for end-stage ankle arthritis.

Methods: Patients who received TAA with the INBONE II prosthesis between September 2016 and August 2021 were included in the study. A total of 68 patients were enrolled and divided into two groups based on age: the younger group (28 patients age ≤ 50 years) and the elderly group (40 patients age ≥ 65 years). Demographic data and patient-reported outcomes, including 36-Item Short-Form Health Survey (SF-36), American Orthopedic Foot & Ankle Society (AOFAS), Foot Function Index (FFI), and Visual Analogue Scale (VAS) scores, were collected preoperatively and at the latest follow-up. Radiographic measurements, including tibial articular surface angle (TAS), talar tilt angle (TT), and tibial lateral surface angle (TLS), were evaluated on weight-bearing images preoperatively and at the latest follow-up. Range of motion (ROM) and complications were documented. Patient satisfaction was assessed using a five-point Likert scale.

Results: With a median follow-up of 4 years, there were no statistically significant differences in AOFAS and SF-36 scores between the two groups at the latest follow-up. However, the elderly group showed slightly lower VAS and FFI scores compared to the younger group, while the younger group demonstrated slightly greater dorsiflexion angles. There were no statistically significant differences in radiographic evaluations, patient satisfaction, and complications between the two groups.

Conclusion: The 4-year postoperative outcomes of TAA using the INBONE II prosthesis were comparable between patients younger than 50 years and those older than 65 years, indicating that age alone may not serve as a definitive criterion for patient selection in TAA with this implant.

Trial Registration: Retrospectively registered.

Level of Evidence: 4.

Objective: The arthroscopic management of concomitant ischiofemoral impingement (IFI) and femoroacetabular impingement (FAI) frequently necessitates iliopsoas release; however, concerns regarding potential iatrogenic muscle atrophy and strength deficits remain unresolved. Therefore, the purpose of this study was to evaluate the clinical outcomes, volumetric changes, muscle morphology, and objective isokinetic muscle strength in patients undergoing arthroscopic treatment for concomitant IFI and FAI involving iliopsoas release.

Methods: This retrospective matched-cohort study analyzed patients treated between January 2019 and January 2020. It included 15 female patients (IFI + FAI group) who underwent arthroscopic IFI decompression and iliopsoas release, and 15 propensity-matched patients (Isolated FAI group) treated for FAI alone. At a minimum 2-year follow-up, patient-reported outcomes (PROs) were assessed. Muscle morphology was evaluated on MRI using 3D volumetric reconstruction for muscle volume, and the Goutallier classification was used to assess fatty infiltration at three standardized anatomical levels. Functional recovery was objectively measured using isokinetic hip flexor and extensor strength testing at 60°/s and 180°/s, comparing the involved hip to the uninvolved contralateral side. Statistical analyses included paired t-tests, Mann–Whitney U tests, and Wilcoxon signed-rank tests.

Results: Both groups demonstrated significant improvements in PROs postoperatively (p < 0.001). Volumetric analysis revealed a significant reduction in iliopsoas muscle volume (25.5% decrease) in the IFI + FAI group postoperatively. Despite this volumetric reduction, postoperative MRI demonstrated preservation of muscle quality, as evidenced by low Goutallier grades (Grade < 1) and no significant difference in fatty infiltration compared to the control group (p > 0.05). Functionally, isokinetic testing demonstrated significant deficits in peak flexion torque compared to the healthy contralateral side (p < 0.001). Notably, while outcomes for activities of daily living were satisfactory, a statistically significant difference was observed in the Substantial Clinical Benefit (SCB) achievement rate regarding sports function between the groups.

Conclusion: Iliopsoas release resulted in significant strength deficits, but no significant changes in muscle morphology were observed. However, patient-reported outcomes (PROs) showed improvement, with no significant increase in fatty infiltration, suggesting that functional recovery may occur despite structural deficits.

Objective: Repair of large bone defects remains a clinical challenge in orthopedics. Optimal porosity is pivotal for the osteogenic induction of porous tantalum scaffolds. This study aimed to investigate the appropriate porosity of porous tantalum scaffolds for osteogenic induction.

Methods: Porous tantalum scaffolds with approximately 45%, 55%, and 65% porosity were fabricated via parametric engineering and laser powder bed fusion 3D printing. Computational fluid dynamics simulations were used to analyze their hydrodynamic characteristics, and in vitro experiments were performed to evaluate their biocompatibility and osteogenic differentiation capacity.

Results: The porosity of scaffolds can influence the internal fluid microenvironment and further regulate the behavior of bone marrow mesenchymal stem cells. Compared to scaffolds with porosities of 45% and 65%, those with a porosity of approximately 55% exhibited optimal hydrodynamic properties, superior cellular compatibility, and outstanding osteogenic differentiation capacity, along with the highest mineralized nodule density and significantly elevated expression levels of osteogenesis-related genes (p < 0.001) and proteins (p < 0.01).

Conclusion: This study confirms that approximately 55% porosity is more suitable for osteogenic induction in porous tantalum scaffolds. These findings provide theoretical and experimental evidence for subsequent in vivo studies and clinical translation of porous tantalum scaffolds.

Objective: The clinical application of the Nine-grid Area Division Method for pedicle puncture in L-OVCF is limited by high technical thresholds and low efficiency. This study aimed to develop an AI-integrated automated system for L-OVCF diagnosis and pedicle puncture planning by combining the nine-grid method with deep learning, and to validate its diagnostic accuracy, planning consistency, and clinical application efficiency.

Methods: A multicenter CT dataset of L-OVCF patients was collected from three hospitals affiliated with Capital Medical University (January 2020–December 2022). A two-stage improved U-Net architecture was constructed for automated lumbar vertebral segmentation, and a 3D ResNet50 network was used for L-OVCF identification. A geometric algorithm was developed to realize automated puncture path planning based on the Nine-grid Area Division Method. The performance of the segmentation and diagnosis modules was evaluated with DSC, AUC, and Hausdorff Distance. 20 cases were randomly selected to compare the consistency of puncture planning between the AI system and senior surgeons' manual planning, and the planning efficiency and resource consumption of the two methods were analyzed.

Results: The proposed two-stage U-Net achieved an overall DSC of 0.934 for vertebral segmentation, significantly outperforming the single-stage nnU-Net model. The L-OVCF identification model yielded a high degree of accuracy with AUC of 0.918 (95% CI: 0.885–0.925). The automated planning results showed extremely high consistency with manual planning (DSC = 0.958, IoU = 0.921, HD = 486.7 μm), and the planning efficiency was significantly improved with memory consumption within the capacity of standard clinical workstations.

Conclusions: The developed AI-integrated system accurately reproduces the preoperative planning logic of senior surgeons, with high diagnostic accuracy and puncture planning consistency, while markedly improving planning efficiency and reducing the technical threshold of the nine-grid method. It has good clinical translational potential and can provide a reliable auxiliary tool for the precise and minimally invasive treatment of L-OVCF.

Objectives: Mixed-type cervical spondylosis (MCS) refers to a degenerative disease in which multiple structures of the cervical spine are affected. Achieving adequate multi-site decompression with minimal muscle dissection is technically demanding in cervical spine surgery. This study aims to evaluate the feasibility of one-stage decompression for MCS with multi-site lesions utilizing biportal endoscopic spinal surgery (BESS). A combined approach involving keyhole foraminotomy and unilateral laminotomy for bilateral decompression (Keyhole-ULBD) was proposed and applied in clinical practice.

Methods: This study was designed as a technical descriptive study. Patients diagnosed with MCS who underwent Keyhole-ULBD using the BESS technique between October 2022 and June 2024 were enrolled. Demographic characteristics and baseline clinical data were collected. Clinical outcomes were evaluated using the Visual Analog Scale (VAS) and modified Japanese Orthopedic Association (mJOA) scores at 1, 6, and 12 months postoperatively. Radiological parameters were measured to assess the extent of decompression and cervical stability. Paired t-test and Wilcoxon signed-rank test were applied to compare preoperative and postoperative measurements, with statistical significance set at p < 0.05.

Results: A total of 12 MCS patients were enrolled. Compared with preoperative values, there was a significant increase in foraminal area (from 0.19 ± 0.06 to 0.25 ± 0.06 cm²) and spinal canal area (from 1.36 ± 0.21 to 2.75 ± 0.48 cm²), as well as a marked improvement in VAS-neck scores (from 5.00 ± 1.67 to 1.50 ± 0.55) and mJOA scores (from 12.01 ± 2.19 to 15.83 ± 1.83) at 1 month postoperatively. At the 1-year follow-up, both radiological decompression and improvements in pain and functional outcomes were sustained, demonstrating stable long-term clinical efficacy.

Conclusion: The Keyhole-ULBD technique offers a safe and effective approach for one-stage decompression in MCS.

Objective: Forearm diaphyseal metastases are rarely encountered and are predisposed to pathological fracture because torsional stress is repeatedly generated during pronation–supination. In addition, relatively long osteotomy is often required by conventional intercalary prostheses, and limited bone stock in the radius and ulna may be sacrificed. In this study, the feasibility and short- to mid-term outcomes of an intercalary mortise–tenon diaphyseal prosthesis designed to enable ultra-short osteotomy were evaluated in patients undergoing reconstruction after en bloc resection of forearm metastases.

Methods: Five consecutive patients with diaphyseal metastases of the forearm (radius, n = 3; ulna, n = 2) who were treated with en bloc resection and implantation of a custom mortise–tenon diaphyseal prosthesis between June 2019 and November 2023 were retrospectively reviewed. Pain and limb function were assessed using the visual analogue scale (VAS) and Musculoskeletal Tumor Society (MSTS) score, respectively. Osteotomy length, perioperative findings, complications, local recurrence, implant-related events, and survival were recorded. Pre- and postoperative VAS and MSTS scores were compared using the Wilcoxon signed-rank test.

Results: A mean follow-up of 40.2 months (range, 19–72) was achieved. A mean osteotomy length of 3.6 cm (range, 3.0–4.0) was recorded, and reconstruction was completed with limited bone resection. Pathological fractures were observed in three patients, whereas Mirel's scores of 10 were documented in the remaining two patients. At final follow-up, the mean VAS score was reduced to 0.4 (range, 0–1), and the mean MSTS score was increased to 26.2 (range, 25–27); statistical significance was reached for both comparisons. The 12- and 24-month survival rates were estimated at 100% and 80%, respectively. No local recurrence, implant failure, or major postoperative complications were observed during follow-up.

Conclusion: In this small retrospective case series, intercalary reconstruction using a mortise–tenon diaphyseal prosthesis after en bloc resection was shown to be feasible for forearm diaphyseal metastases, and substantial pain relief together with satisfactory functional recovery was achieved. Long-term durability and oncologic outcomes should be confirmed in larger studies.

Objectives: Lumbar ligamentum flavum cyst is a rare degenerative disease of the spine, which remains poorly reported in the literature. Although full endoscopic surgery has been used for cyst resection, there is no well depicted and accepted technique so far. In this report, we introduce our preliminary experience of the surgical technique for piecemeal cyst resection with a uniaxial large working channel spinal endoscope, and provide the detailed description of endoscopic pathological anatomy.

Methods: This is a retrospective review of a predesigned three-step uniaxial full endoscopic surgical technique. The lumbar ligamentum flavum cysts were removed using a large working channel spinal endoscope. The spinal endoscopic database of the author's department was retrospectively reviewed for patients treated from February 2023 to December 2024. Patients diagnosed as lumbar ligamentum flavum cysts and treated with this technique were included for analysis. The basic information, complications and follow-up clinical outcome parameters (visual analogue scale, VAS, Oswestry Disability Index, ODI, modified MacNab criteria) were collected for evaluation (Shapiro–Wilk test, Wilcoxon's signed-rank test).

Results: Totally, seven patients with ligamentum flavum cyst were included for analysis. All the surgical procedures were successfully performed. The brownish-red soft jelly-like contents and serious adhesion between the ventral wall of the cyst and the dura were notable features of ligamentum flavum cyst. No intraoperative complications were found. The patients were followed up for at least 1 year. The clinical outcomes were satisfactory. Visual analogue scale and Oswestry Disability Index at all follow-up time points were significantly improved (p < 0.05). The excellent and good rate according to modified MacNab criteria was 100% at the last follow-up.

Conclusion: Uniaxial large working channel spinal endoscopy is potentially a safe and effective choice in minimally invasive surgery to remove lumbar ligamentum flavum cyst.