2025-04-20 2025, Volume 17 Issue 4

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  • REVIEW ARTICLE
    Qiangqiang Li , Aikeremu Aierken , Jianghui Qin , Dongyang Chen , Qing Jiang
    2025, 17(4): 981-989. https://doi.org/10.1111/os.14349

    Blocking the infrapatellar branch of the saphenous nerve (IPBSN) can provide analgesic benefits for patients with postoperative acute pain or chronic pain, with minimal adverse effects. To evaluate the analgesic efficacy and potential adverse events associated with IPBSN block in patients suffering from acute or chronic knee pain. We conducted a systematic review across PubMed, Cochrane, Web of Science, and Embase to identify all relevant randomized controlled trials (RCTs) and cohort studies according to predefined selection criteria. The study quality of the RCTs was evaluated using the Cochrane risk of bias assessment tool, while cohort studies were assessed using the ROBINS-I risk of bias tool. The primary outcomes measured were pain intensity and opioid consumption following the nerve block. A total of eight studies were included in this systematic review, encompassing 613 subjects with 276 participants in the control group and 337 participants in the IPBSN block group. The level of evidence was rated high for the RCTs and moderate for the cohort studies. The nerve block was administrated either through the injection of local anesthetic or percutaneous cryoneurolysis targeting the IPBSN. The results indicated that the IPBSN block significantly improved pain relief and reduced opioid consumption in patients with acute postoperative or chronic pain, with no significant difference in the rate of adverse events relating to the procedures or device. The IPBSN block holds promise for improving pain relief and reducing opioid consumption. However, further well-designed randomized controlled trials are needed to confirm these results.

  • REVIEW ARTICLE
    Yizhong Ma , Lu Mao , Guanyi Liu , Lihua Hu , Kaixuan Chen
    2025, 17(4): 990-998. https://doi.org/10.1111/os.14355

    The traditional posterior median approach laminectomy is widely used for lumbar decompression. However, the bilateral dissection of paraspinal muscles during this procedure often leads to postoperative muscle atrophy, chronic low back pain, and other complications. The posterior midline spinous process-splitting approach (SPSA) offers a significant advantage over the traditional approach by minimizing damage to the paraspinal muscles. SPSA reduces the incidence of muscle atrophy and chronic low back pain while maintaining the integrity of the posterior spinal structures. The technique involves longitudinal splitting of the spinous process, which allows for adequate access to the lamina for decompression without detaching the paraspinal muscles. As a result, it provides a clearer surgical field and facilitates muscle preservation, which reduces the risk of postoperative complications. Additionally, SPSA requires only standard surgical instruments, making it accessible in most surgical settings. This paper reviews the anatomical considerations, surgical techniques, and clinical applications of the SPSA, highlighting its effectiveness in reducing muscle atrophy and improving recovery outcomes. The paper also discusses its potential in treating conditions such as lumbar spinal stenosis, disc herniation, and spondylolisthesis. Furthermore, it emphasizes the need for future research to establish the long-term benefits of SPSA and refine surgical techniques. The results suggest that SPSA is a promising alternative to traditional approaches, with better outcomes in terms of muscle preservation and overall recovery.

  • REVIEW ARTICLE
    Wenqing Wei , Liang Cheng , Yating Dong , Tianyuan Zhang , Yaolong Deng , Jiale Gong , Fang Xie , Junlin Yang
    2025, 17(4): 999-1020. https://doi.org/10.1111/os.14362

    Classification systems for Adolescent Idiopathic Scoliosis (AIS) play an important role in guiding both surgical planning and conservative treatments. Traditional 2D classification systems, such as the Lenke, King and Lehnert-Schroth classifications, have been widely used for the clinical diagnosis and treatment of scoliosis. However, with the growing understanding of the three-dimensional nature of scoliosis and advancements in 3D reconstruction technologies, 3D classification systems are gaining increasing attention. This paper reviews the current applications, advantages, and limitations of different 2D and 3D classification systems, focusing on their clinical significance in treatment planning. While 3D classification systems offer clear advantages in capturing the complexity of spinal deformities, their clinical implementation faces challenges such as high costs and technical complexity. Additionally, studies show that computer-assisted technologies, artificial intelligence can significantly improve the accuracy and consistency of classification systems, reducing human errors. The paper also explores the future directions of classification system development, emphasizing the potential of combining 2D and 3D technologies and the impact of these advancements on personalized scoliosis treatment.

  • REVIEW ARTICLE
    Yuxiong Xu , Yizhuo Yang , Hanan Song , Ming Li , Weihao Shi , Tongwu Yu , Jianhao Lin , Yanli Yu
    2025, 17(4): 1021-1035. https://doi.org/10.1111/os.14365

    With the increasing prevalence of knee osteoarthritis (KOA), the limitations of traditional treatments, such as their limited efficacy in halting disease progression and their potential side effects, are becoming more evident. This situation has prompted scientists to seek more effective strategies. In recent years, exercise therapy has gained prominence in KOA treatment due to its safety, efficacy, and cost-effectiveness, which are underpinned by the molecular actions of exerkines. Unlike conventional therapies, exerkines offer specific advantages by targeting inflammatory responses, enhancing chondrocyte proliferation, and slowing cartilage degradation at the molecular level. This review explores the potential mechanisms involved in and application prospects of exerkines in KOA treatment and provides a comprehensive analysis of their role. Studies show that appropriate exercise not only promotes overall health, but also positively impacts KOA by stimulating exerkine production. The effectiveness of exerkines, however, is influenced by exercise modality, intensity, and duration of exercise, making the development of personalized exercise plans crucial for KOA patients. Based on these insights, this paper proposes targeted exercise strategies designed to maximize exerkine benefits, aiming to provide novel perspectives for KOA prevention and treatment.

  • CLINICAL ARTICLE
    Yang Xiao , Wenbin Shuai , Zhuang Zhang , Limin Liu , Yueming Song , Xi Yang
    2025, 17(4): 1036-1044. https://doi.org/10.1111/os.14350

    Objective: Pear-shaped disc could increase the risk of intraoperative end-plate injury, which may lead to postoperative sclerotic Modic Changes (MCs). However, there are no studies on the relationship between pear-shaped disc and postoperative sclerotic MCs. Therefore, this study investigates the risk factors for postoperative sclerotic MCs following transforaminal lumbar interbody fusion (TLIF). Specifically, the study focuses on the impact of pear-shaped disc on the occurrence of postoperative sclerotic MCs and evaluates its influence on clinical outcomes.

    Methods: A total of 411 patients undergoing TLIF between January 2018 and January 2022 were included. Among them, 50 developed postoperative sclerotic MCs, while 361 did not. The two groups were matched based on various parameters. Clinical and radiographic evaluations, including visual analogue scale (VAS), Oswestry disability index (ODI), lumbar X-ray, CT, and MRI, were performed. Statistical analysis included independent sample t test, Pearson's chi-square test, and binary logistic regression analysis.

    Results: After pairing, a total of 100 patients were included, including 50 patients in postoperative sclerotic MCs group and 50 patients in non-MCs group. There were 27 pear-shaped discs in the postoperative sclerotic MCs group, significantly higher than 7 in the non-MCs group (p < 0.001). Besides, BMI, endplate injury, and cage subsidence in the postoperative sclerotic MCs group were significantly higher than those in the non-MCs group, but the fusion rate was significantly lower than that in the non-MCs group. The postoperative and follow-up SL and surgical corrections of SL in postoperative sclerotic MCs group were significantly higher than those in non-MCs group. The independent risk factors identified for postoperative sclerotic MCs include pear-shaped disc and higher BMI.

    Conclusion: Pear-shaped disc and higher body mass index (BMI) as independent risk factors for postoperative sclerotic MCs. Patients with sclerotic MCs exhibited a lower fusion rate, increased cage subsidence, and poorer symptom improvement compared to those without MCs.

  • CLINICAL ARTICLE
    Zhenghui Hu , Chen Sun , Hongquan Heng , Jian Li , Hainan Chen , Fuchao Chen , Peng Su , Dengfeng Wang
    2025, 17(4): 1045-1056. https://doi.org/10.1111/os.14351

    Objective: Inferior pole patellar fractures (IPPFs) pose a significant challenge due to their complex fracture patterns and high risk of complications associated with current treatment methods. This study aims to (1) characterize the fracture patterns of IPPFs using fracture mapping and (2) compare the biomechanical stability and clinical outcomes of treatment with anchor suture with patellar cerclage versus Kirschner-wire tension band combined with patellar cerclage.

    Methods: (1) A retrospective analysis was conducted on 61 patients with IPPF. For each case, fracture reduction was manually simulated, with fracture lines and fragments overlaid onto a complete patella template to identify fracture patterns. (2) Finite-element models were used to analyze the mechanical properties of anchor suture and titanium cable cerclage treatment and Kirschner-wire tension band combined with patellar cerclage in treating IPPFs. Additionally, a retrospective analysis of clinical data was performed on 57 patients with IPPF (AO/OTA 34 A1) treated at our institution between January 1, 2023, and December 25, 2023. Of these, 18 patients underwent anchor suture and titanium cable cerclage (Group A), and 39 underwent Kirschner-wire tension band combined with patellar cerclage (Group B). We compared operative time, final knee range of motion, incidence of secondary surgery, postoperative complications, and functional recovery between the two groups based on medical records and follow-up results.

    Results: (1) IPPFs were predominantly comminuted, with fracture lines on the anterior view concentrated laterally and near the superior surface of the inferior pole. Fracture lines became more sparse as they approached the distal patella. The posterior view was similar to the anterior, with the majority of fractures near the superior surface of the inferior pole. (2) Finite-element analysis revealed no significant differences between the two groups in terms of displacement and stress. Operative time was similar between the groups (p > 0.05), as were final knee range of motion (p > 0.05) and postoperative Bostman scores (p > 0.05). Group A had no postoperative complications or readmissions, while Group B had two cases of hardware irritation and one case of knee joint infection.

    Conclusion: The fracture lines of IPPF are varied, often comminuted, and correlate with the mechanism of injury. Biomechanical and clinical outcomes suggest that anchor suture with patellar cerclage is a viable option for stabilizing IPPF.

    Trial Registration: ClinicalTrials.gov identifier: NCT06736639

  • CLINICAL ARTICLE
    Xiaolong Zhang , Xiwen Feng , Lingfei Ouyang , Shan Shu , Lebin Zhuang , Weichao Gui , Sheng Zhang , Zilong Yao , Gang Wang , Hua Liao , Jijie Hu
    2025, 17(4): 1057-1066. https://doi.org/10.1111/os.14353

    Objectives: Treating femoral neck fractures remains a significant challenge for orthopedic surgeons and imposes a substantial economic burden on developing regions. Current novel internal fixation methods demonstrate excellent biomechanical performance. However, these new internal fixation methods are still associated with various complications. This study aimed to report the clinical complications of femoral neck system (FNS) and biplane double-supported screw fixation (BDSF) treatments for femoral neck fractures at our institution and provide directions for selecting cost-effective internal fixation methods.

    Methods: A retrospective case–control study of adult patients with femoral neck fractures treated with BDSF or FNS was conducted at Nanfang Hospital from April 2019 to April 2022. General medical records were collected both preoperatively and intraoperatively. Primary complication measures included osteonecrosis of the femoral head, nonunion, screw-out, and subtrochanteric fractures, along with femoral neck shortening. The primary functional measure evaluated was the Harris hip score. This study employed t-test, Wilcoxon rank-sum test, and chi-square test to statistically analyze the data.

    Results: Statistically significant differences were observed between the BDSF and FNS groups in terms of surgery duration (60.8 ± 12.6 min vs. 71.0 ± 12.0 min), incision length (5.5 ± 1.2 cm vs. 9.1 ± 1.6 cm) and hospitalization costs (39563.8 ± 9086.4 RMB vs. 24960.4 ± 10154.4 RMB). No statistically significant differences between the BDSF and FNS groups were found in the baseline data, blood loss or hospital stay. Moderate femoral neck shortening was significantly less common in the BDSF group than in the FNS group (27.1% vs. 61.5%, p = 0.016). Postoperatively, no statistically significant differences in complication rates, such as femoral head necrosis, nonunion, subtrochanteric fractures or screw-out, were observed between the BDSF and FNS groups.

    Conclusions: This study revealed no significant difference in the incidence of postoperative complications such as femoral head necrosis, nonunion or screw cut-out between BDSF and FNS. Although BDSF has drawbacks, such as a long learning curve and the potential to cause subtrochanteric fractures, it is cost-effective and better maintains the length of the femoral neck. The modified BDSF technique may be more suitable for developing regions with limited health care budgets.

  • CLINICAL ARTICLE
    Xuemeng Mu , Hengyan Zhang , Jia Zhang
    2025, 17(4): 1067-1074. https://doi.org/10.1111/os.14354

    Objectives: Dual energy x-ray absorptiometry (DXA) provides incomplete information about bone strength. There are few data on the relationship between osteoporosis-related examinations and bone strength. The objective of the present study was to determine which osteoporosis-related examinations best predicted trabecular bone strength, and to enhance a formula for predicting bone strength on the basis of bone density examination.

    Methods: This observational study included postmenopausal women (aged over 50 years) who underwent unilateral percutaneous kyphoplasty (PKP) surgery in the lumbar spine between September 2021 and June 2023. The pressure within each balloon expansion circle was extracted to reflect the true bone strength. The NHANES 2013–2014 data were used to assess the performance of the formula. The performance of the formula was compared with that of the observed actual fractures. Bland–Altman analysis was used to compare the agreement between the formula and the fracture risk assessment tool (FRAX) score.

    Results: A total of 40 postmenopausal women (mean age ± standard deviation, 70.90 years ± 10.30) were enrolled. The average balloon pressure was 59.23 psi (± 12.40, means ± SDs). The mean BMD of total lumbar spine (average of L1–L4) was 0.89 g/cm2 ± 0.20 (mean ± standard), and the Pearson correlation coefficient between lumbar BMD and bone strength was 0.516. After adjusting for age and BMI, the DXA response rate to bone strength reached 72%. Calibration plots of the observed actual fractures versus those estimated via the bone strength formula were considered good fits. The Bland–Altman analysis revealed a nonsignificant difference between the formula and the FRAX score in predicting fracture risk.

    Conclusions: After adjustment, the DXA response rate to bone strength reached 72%, indicating a strong correlation. In addition, Bone Strength = DXA × 27 − Age × 0.585-BMI × 0.887 + 98.

  • CLINICAL ARTICLE
    Muradil Mardan , Mardan Mamat , Parhat Yasin , Xiao-Yu Cai , Guo-Jun Fan , Tao Xu , Bo Li , Peng-Bo Chen , Ze-Yu Lu , Wei-Bin Sheng , Sheng-Dan Jiang , Lei-Sheng Jiang , Xin-Feng Zheng
    2025, 17(4): 1075-1085. https://doi.org/10.1111/os.14356

    Objective: Coronal malalignment is a common feature of adult spinal deformity, and accurate classification is essential for diagnosis and treatment planning. However, variations in interpretation among clinicians can impact classification consistency. By assessing the reliability and applicability of these systems across different medical experts, this study seeks to establish a standardized approach to enhance clinical outcomes. This study aimed to evaluate the inter- and intra-observer agreement of two classification systems for coronal malalignment in adult spinal deformity patients, as proposed by Qiu et al. and Obeid et al.

    Methods: We analyzed 70 cases of adult spinal deformity collected between January 1, 2010, and April 20, 2023, using the classification systems proposed by Qiu et al. and Obeid et al. To assess inter- and intra-rater agreement, the same group of researchers re-evaluated all cases in a random order after a 4-week interval. We used the kappa statistic (κ) for inter- and intra-rater agreement assessment.

    Results: Qiu's classification system: Inter-rater agreement: Substantial agreement (κ = 0.76; 95% CI: 0.72–0.80) for Type A, Type B, and Type C. Intra-rater agreement: Nearly perfect agreement (κ = 0.83; 95% CI: 0.78–0.89) within raters for Type A, Type B, and Type C.Obeid's classification system: Inter-rater agreement: Almost perfect agreement (κ = 0.85; 95% CI: 0.83–0.87) for Type 0, Type 1, and Type 2. Complete system: Substantial agreement (κ = 0.68; 95% CI: 0.65–0.71) for all types and subtypes. Intra-rater agreement: Almost perfect at the type level (κ = 0.88; 95% CI: 0.83–0.93) and substantial at the subtype level (κ = 0.75; 95% CI: 0.65–0.85).

    Conclusions: The research findings indicate a high level of agreement between the classification system described by Qiu et al. and the classification system proposed by Obeid et al. This agreement supports the widespread adoption and utilization of these classification systems in future clinical studies.

  • CLINICAL ARTICLE
    Shijie Jiang , Weizhi Ren , Ruixia Zhu , Dimitris Dimitriou , Rongshan Cheng , Xiaojun Jia , Dong Zheng , Yuji Wang , Wei Xu
    2025, 17(4): 1086-1094. https://doi.org/10.1111/os.14358

    Objective: The incidence of anterior cruciate ligament (ACL) ruptures has been increasing annually. However, clinical surgeons have overlooked the impaction fractures of the posterolateral tibial plateau and lateral femoral condyle in patients with ACL ruptures. The purpose of the present study was to report the detection rate of the posterolateral tibial plateau impaction fractures in patients with ACL ruptures, and to evaluate the functional outcomes of patients following ACL reconstruction (ACLR) without treatment of the tibial fractures at a 2-year postoperative follow-up.

    Methods: Four hundred eighty-eight patients treated for ACL ruptures between January 2016 and June 2020 were retrospectively reviewed, and the posterolateral tibial plateau impaction fractures were classified based on MRI assessment. The detection rate of the posterolateral tibial plateau impaction fractures was calculated, and the functional outcomes (SF-12 Mental Component Summaries, SF-12 Physical Component Summaries, Tegner, Lysholm, IKDC, and KOOS) were evaluated at a 2-year postoperative follow-up.

    Results: The detection rate of posterolateral tibial plateau impaction fractures was 41.6% among ACL ruptures. Of these, 285 cases (58.4%) had no fractures, 98 cases (20.1%) had type I impaction fractures, 41 cases (8.4%) had type IIA impaction fractures, 15 cases (3.1%) had type IIB impaction fractures, 22 cases (4.5%) had type IIIA impaction fractures, and 27 cases (5.5%) had type IIIB impaction fractures. Patients with type IIIA or IIIB impaction fractures showed an increased detection rate of contact mechanism compared to the other subgroups. Significant differences in Tegner (postoperation) and KOOS (QOL) were found between no fracture and type IIIB impaction fractures in patients following ACLR.

    Conclusions: The detection rate of posterolateral tibial plateau impaction fractures in patients with ACL ruptures was high. Patients with type IIIB impaction fractures following ACLR had poor functional outcomes.

  • CLINICAL ARTICLE
    Binglong Li , Xuezhou Li , Weibo Zheng , Shusheng Wei , Baoqing Zhang , Jianwei Liu , Yongyuan Chen , Dan Wang , Qunshan Lu , Peilai Liu
    2025, 17(4): 1095-1104. https://doi.org/10.1111/os.14360

    Objective: Intermittent pneumatic compression (IPC) is considered the standard of care for preventing venous thromboembolism (VTE) in the hospital setting. However, its widespread adoption after hospitalization has been limited due to its shortcomings in obstruction of venous valves and blood reflux. The objective of this study is to compare the effects of continuous graduated pneumatic compression (CGPC), a new device with a novel mechanism, and IPC on lower hemodynamics and the incidence of VTE in patients undergoing arthroplasty.

    Methods: We randomized 123 participants undergoing knee arthroplasty to receive either IPC or CGPC from June 2022 through August 2023. An experienced sonographer used a Doppler ultrasound scanner to obtain hemodynamic indicators of venous blood. The primary outcome was the blood velocity of the femoral vein measured by a Doppler scanner. Secondary outcomes included the hemodynamic of the femoral vein and popliteal vein, quality of life at discharge and 30 days after surgery, symptomatic and asymptomatic VTE up to 30 days, and adverse events related to the IPC and CGPC device. For statistical analyses, Student's t-test, analysis of covariance, and the Mann–Whitney U test were used. Statistical significance was indicated with p < 0.05.

    Results: There was no significant difference in femoral vein velocity between the IPC and CGPC groups. However, CGPC demonstrated a significant increase in femoral vein flow compared to the IPC group, with a median (interquartile) increasing from 158.9 (122.9, 204.3) to 265.6 (203.3, 326.8) mL/min in the CGPC group and from 139.0 (103.3, 175.9) to 189.6 (161.4, 270.8) mL/min in the IPC group (p < 0.001). Similar trends were observed in popliteal vein measurements. The differences between the two groups were similar in terms of quality of life, incidence of VTE, and adverse events.

    Conclusion: The CGPC device provides a substantial increase in blood flow compared to the IPC device. Its safety and effectiveness have been preliminarily validated. The CGPC device presents a promising alternative for VTE prophylaxis in arthroplasty.

    Trial Registration: Chinese Clinical Trial Registry (registration number: ChiCTR2300078201)

  • CLINICAL ARTICLE
    Hongtao Ding , Xiao Han , Yonggang Xing , Yajun Liu , Da He , Xiaoguang Han
    2025, 17(4): 1105-1113. https://doi.org/10.1111/os.14361

    Objective: Unilateral biportal endoscopic discectomy (UBE) is an emerging and minimally invasive surgeryfor lumbar spinal degenerative disease. However, the efficacy, safety and the radiological changes of dural sac and paraspinal muscle of UBE compared with the conventional percutaneous transforaminal endoscopic discectomy (PTED) remains to be determined. The purpose of the study was to comprehensively compare the clinical efficacy between UBE and PTED in the surgical treatment of lumbar spinal degenerative disease.

    Methods: The clinical and radiological data of patients who underwent single-segment endoscopic surgery for lumbar spinal degenerative disease in our hospital from January 2021 to June 2022 were collected in the retrospective study. The visual analogue score (VAS) for back and leg pain, Oswestry disability index (ODI) before and 3, 6, and 12 months postoperative, changes of the cross-sectional area of the dural sac area and paraspinal muscles on axial T2-weighted MRI, operation time, intraoperative complications, MacNab criteria for evaluating efficacy at 12 months postoperatively, and recurrence rate of symptoms within 12 months were compared between patients undergoing PTED and UBE surgeries.

    Results: A total of 142 patients were included. Among them 74 patients underwent PTED surgery, and 68 patients underwent UBE surgery. No statistically significant differences were identified between the groups in demographic variables. The average VAS and ODI scores in both groups showed significant improvement during the follow-up but without statistically significant difference between the groups. The average operation time in the PTED group was 74.82 ± 19.49 min shorter than the 81.36 ± 21.37 min in the UBE group, exhibiting no statistically significant difference. Although the incidence of complications and recurrence was lower in the UBE group (4.05% vs. 1.47%, p = 0.354; 4.05% vs. 1.47%, p = 0.354, respectively), these differences did not reach statistical significance. The dural sac area in the PTED group increased byan average of 43.16 ± 14.62 cm2, and it was 68.53 ± 16.42 cm2 in the UBE group. Despite the dural sac area increased in both groups, the UBE group had a statistically significant greater improvement than the PTED group (p = 0.000). The area of the paraspinal muscle in the UBE group was significantly greater postoperatively (34.54 ± 2.75 cm2 vs. 36.22 ± 2.96 cm2, p = 0.001) and significantly less than in the PTED group at 12 months postoperatively (31.17 ± 2.59 cm2 vs. 29.46 ± 3.11 cm2, p = 0.001).

    Conclusion: Both PTED and UBE surgeries can achieve satisfactory improvement in symptoms and function for patients with lumbar spinal degenerative disease and can be well-maintained as a first-line minimally invasive treatment. However, the UBE technique can achieve a better decompression area to restore the normal shape of the dural sac but may lead to greater paraspinal muscle damage and atrophy.

  • CLINICAL ARTICLE
    Lei Li , Yan Wang , Hao Zhang , Jialuo Han , Changpeng Qu , Yihao Sun , Hao Tao , Xuexiao Ma
    2025, 17(4): 1114-1123. https://doi.org/10.1111/os.14363

    Objectives: The advent of O-arm navigation optimized the oblique lumbar interbody fusion (OLIF) procedure, allowing the operator to simultaneously perform OLIF and percutaneous posterior pedicle screw implantation without patient position change, thus improving the fluency and accuracy of the OLIF procedure (called as OLIF360). Nevertheless, a consensus regarding its suitability for patients with severe spinal stenosis remains elusive. This study aims to investigate the clinical efficacy of OLIF360 and its imaging changes in severe lumbar spinal stenosis cases.

    Methods: This retrospective study analyzed clinical data from 63 patients with severe lumbar spinal stenosis. Fourteen patients were treated with OLIF360, and another 37 patients were treated with posterior lumbar interbody fusion (PLIF). Lumbar spinal stenosis was assessed using the modified Schizas classification. Clinical efficacy scale scores and postoperative imaging parameter changes were compared between the two groups. Shapiro–Wilk, t-tests or Mann–Whitney U tests, repeated measures ANOVA, and Bonferroni post hoc tests were applied for statistical analysis.

    Results: Both groups showed significant improved pain (p < 0.05). At 1-month and 3-month postoperative follow-ups, OLIF360 group scores superior in Visual Analog Scale than PLIF group (p < 0.05). Greater disc height and lumbar lordosis were displayed in OLIF360 group than PLIF group (p < 0.05). No significant difference in screw placement accuracy between groups was observed. Moreover, significant increases in spinal canal area postoperatively (71.04 ± 6.27 mm2 preop to 109.65 ± 12.34 mm2 postop, p < 0.05) and bilateral foraminal areas were found in the OLIF360 group.

    Conclusion: OLIF360 can have promising short-term efficacy for severe lumbar stenosis treatment with shorter recovery time than PLIF.

  • CLINICAL ARTICLE
    Guihu Liu , Xiaolong Wang , Xieyu Wang , Yaxuan Zhang , Yinguang Ma , Haibin Zhou , Guangsi Shen
    2025, 17(4): 1124-1132. https://doi.org/10.1111/os.14364

    Objectives: The accuracy of dual-energy x-ray absorptiometry (DXA) in predicting proximal humerus osteoporosis in patients with rotator cuff tears (RCTs) undergoing arthroscopic rotator cuff repair (ARCR) is uncertain. The aim of this study was to assess the correlation of computed tomography (CT) Hounsfield units (HU) and the deltoid tuberosity index (DTI) with bone mineral density (BMD), and to evaluate the predictive value of HU values for implant selection.

    Methods: This study analyzed the preoperative shoulder CT scans and x-rays of 184 patients who underwent ARCR. Preoperative CT scans were utilized to assess the multiple anatomical parts of the proximal humerus to ascertain the HU values, whereas preoperative x-rays were analyzed to derive the DTI. Among them, 104 patients with preoperative DXA data were grouped according to the WHO diagnostic criteria for osteoporosis to establish the threshold HU values. The correlation between HU values and DTI and the lowest T score on DXA was studied, and the relationship between the HU value and the type of implant selected was discussed. The Pearson correlation coefficient was employed to examine the relationship between HU values, DTI, and T scores. And the Spearman correlation coefficient was employed to examine the relationship between HU values and enhanced fixation.

    Results: There was a significant correlation between the HU values and DTI and the lowest T score (rHU&T score = 0.539–0.576, rDTI&T score = 0.288, p < 0.05). On the basis of the lowest T score grouping, the threshold HU values for diagnosing proximal humeral osteoporosis were obtained: proximal humerus = 47.44, humeral head = 97.62, greater tuberosity = 10.9, and lesser tuberosity = 5.38. There was no correlation between HU values and enhanced fixation (using 5.5-mm anchors or metal anchors instead of 4.5-mm anchors or all-suture anchors) (r = −0.143 to −0.027, p > 0.05).

    Conclusion: Proximal humeral HU values were significantly correlated with DTI and the lowest T score on DXA. When the HU values in the proximal humerus in patients with RCTs fall below the thresholds, the surgery should be carefully planned. No correlation exists between HU values and enhanced fixation, thus further investigation through group studies is warranted.

    Level of Evidence: Level III, study of nonconsecutive patients, diagnostic study.

  • CLINICAL ARTICLE
    Xinhu Guo , Zhaoqing Guo , Weishi Li , Zhongqiang Chen , Qiang Qi , Chuiguo Sun , Woquan Zhong , Bin Su
    2025, 17(4): 1133-1142. https://doi.org/10.1111/os.14367

    Objective: High-grade dysplastic spondylolisthesis (HGDS) is a relatively rare condition mainly involving the L5/S1 segment of the spine and occurring in children and adolescents. Whether surgical fixation should be L5–S1 monosegmental or extended up to L4 remains controversial. This study aimed to compare clinical outcomes and the risk of adjacent segment spondylolisthesis between L5–S1 monosegmental fixation and L4–S1 double-segmental fixation for pediatric HGDS.

    Methods: This is a retrospective control study Pediatric patients diagnosed with HGDS between March 2007 and October 2022 at our hospital were followed up, and their data were analyzed. The study involved 39 HGDS patients (average slip, 70.0%) divided into two groups: the L5–S1 monosegmental reduction and fusion group (L5 group, 16 patients) and the L4–S1 double-segmental reduction and fusion group (L4 group, 23 patients). Radiographic parameters and patient-reported outcomes were collected before surgery and at follow-up and compared between the two groups. Additionally, the prevalence of adjacent segment spondylolisthesis and instability (ASS/ASI) was compared between the groups at the last follow-up. Independent sample t-tests were employed to compare normally distributed data between the two groups. Paired sample t-tests were employed to compare preoperative data with postoperative data. The chi-square test was utilized to compare rates.

    Results: The average age was (12.5 ± 2.3) years. The L4 group had a greater slip percentage (77.6% vs. 59.2%; p < 0.001), a smaller Dub-LSA (60.3° vs. 69.7°; p = 0.022), and a higher slip grade (p = 0.002) than the L5 group, indicating more severe spondylolisthesis in the L4 group. Clinical parameters, namely the visual analog scale, Oswestry disability index, and Japanese Orthopedic Association-29 score, did not significantly differ between the two groups. The L5 group had a higher rate of ASS/ASI than the L4 group (6/16, 37.5% vs. 0/23, 0%; p = 0.002). Of all the ASS/ASI patients, one underwent a second surgery due to L4 spondylolisthesis 2 years after the primary surgery. The remaining five exhibited no symptoms or mild symptoms.

    Conclusions: For pediatric HGDS, both L5–S1 monosegmental fixation and L4–S1 fixation can achieve satisfactory outcomes. However, there is a higher risk of ASS/ASI following L5–S1 fixation than following L4–S1 fixation.

  • CLINICAL ARTICLE
    Guanjie Zeng , Zongze Li , Juedong Hou , Liu Yu , Yuhui Cui , Yongjian Zhu , Ling Yao , Jiarui Chen , Yongquan Cheng , Jianting Chen
    2025, 17(4): 1143-1151. https://doi.org/10.1111/os.14368

    Objective: Spondylolysis, often progressing to spondylolisthesis, commonly defies conservative treatment in refractory cases, indicating a need for surgery. Robot-assisted techniques may provide a stable and effective minimally invasive approach for the treatment of lumbar spondylolysis. To compare the clinical efficacy between robot-assisted percutaneous screw fixation combined with endoscopic bone graft and conventional open screw fixation with bone graft in the treatment of lumbar spondylolysis.

    Methods: A cohort study involving 43 individuals with lumbar spondylolysis who underwent surgical treatment was conducted. From January 2022 to June 2023, 20 patients underwent percutaneous screw fixation combined with endoscopic bone graft while 23 patients underwent conventional open screw fixation with bone graft. The demographic data, parameters related to robotic surgery, perioperative indicators, VAS and ODI scores, pedicle screw accuracy, radiographic fusion outcomes, and follow-up results were systematically recorded, analyzed, and then compared between the two groups. Categorical variables were analyzed using chi-square tests, and continuous variables were evaluated with t-tests or Mann–Whitney U tests following normality assessment, with statistical significance at p < 0.05.

    Results: Compared with the conventional surgery group, the robot-assisted surgery group had significantly less intraoperative blood loss, less postoperative drainage, shorter hospital stay, less intraoperative fluoroscopy times, and radiation exposure dose (p < 0.05). Nevertheless, the duration of the surgery was longer. Postoperative imaging findings showed high screw accuracy in both groups, with a grade A rate of 95% in the robot-assisted group compared with 91.4% in the conventional open surgery group according to the Gertzbein–Robbins scale. Both groups achieved similar improvements in VAS and ODI during 1-year follow-up, and both groups achieved good bone graft fusion (97.5% fusion rate in the robot-assisted group versus 93.5% in the conventional open surgery group).

    Conclusion: Robot-assisted screw fixation combined with endoscopic bone graft provides a safe and reliable minimally invasive treatment of lumbar spondylolysis, with high accuracy of pedicle screw implantation and less radiation exposure dose, less intraoperative trauma, and quicker recovery than conventional open surgery.

  • CLINICAL ARTICLE
    Youwei Ai , Qian Chen , Li Li , Juehan Wang , Ce Zhu , Hong Ding , Yongdi Wang , Zhuojie Xiao , Yuting Zhan , Yueming Song , Ganjun Feng , Limin Liu
    2025, 17(4): 1152-1161. https://doi.org/10.1111/os.14369

    Objective: Pedicle screw loosening is one of the common complications in elderly patients undergoing transforaminal lumbar interbody fusion (TLIF) for lumbar spine disease. Malnutrition, prevalent among elderly patients, has been shown to be associated with increased complications. The Geriatric Nutritional Risk Index (GNRI) serves as a simple indicator of nutritional status. However, the relationship between malnutrition, particularly GNRI, and pedicle screw loosening has not been adequately investigated. This study aims to investigate the relationship between GNRI and pedicle screw loosening following TLIF to guide the perioperative nutritional management of patients and prevent postoperative complications.

    Methods: A retrospective review was conducted on clinical data from patients who underwent single-level TLIF between 2014 and 2022. Data collection encompassed patient demographics, preoperative laboratory parameters, surgery-related data, perioperative radiographic data, and patient-reported outcomes were comprehensively documented. All patients were followed up for a minimum of 12 months. The relationship between GNRI and pedicle screw loosening was evaluated by univariate and multivariate Cox regression analysis, restricted cubic spline (RCS) analysis, receiver operating characteristic (ROC) analysis, and Kaplan–Meier survival analysis.

    Results: A total of 426 patients were included in the study. The rate of pedicle screw loosening rate was 16.4% at a minimum follow-up of 12 months. Patients with pedicle screw loosening exhibited significantly lower GNRI (89.0 ± 8.0 vs. 99.2 ± 9.3, p < 0.001) and volumetric bone mineral density measured by quantitative computed tomography (QCT-vBMD) (84.2 [interquartile range (IQR) 79.6–92.2] vs. 104.0 [IQR 88.2–126.0] mg/cm3, p < 0.001) compared with those in the non-loosening group. Multivariate Cox regression analysis identified sex (hazard ratio [HR] 1.433, 95% confidence interval [CI] 0.714–2.876, p = 0.027), age (HR 1.062, 95% CI 1.014–1.113, p = 0.012), GNRI (HR 0.841, 95% CI 0.711–0.994, p = 0.043), and QCT-vBMD (HR 0.982, 95% CI 0.967–0.997, p = 0.019) as independent risk factors for screw loosening. RCS analysis showed that GNRI was negatively correlated with screw loosening (p < 0.0001). The area under the curve (AUC) for the GNRI in predicting pedicle screw loosening was 0.794, with a cut-off value of 95.590 (sensitivity, 85.7%; specificity 65.2%). Kaplan–Meier survival analysis identified that the lower-level GNRI group exhibited a higher cumulative incidence of screw loosening (log-rank test, p < 0.0001).

    Conclusion: The GNRI was an independent risk factor for postoperative screw loosening in elderly patients undergoing TLIF for lumbar spine disease. Preoperative GNRI may potentially serve as a valuable tool in predicting postoperative screw loosening in elderly patients undergoing TLIF.

  • CLINICAL ARTICLE
    Hao Yan , Mingdong Yu , Huaibin Wang , Rongsheng Dou , Xiaoyan Xia , Ruzhan Yao , Weiqiang Liu , Jesse Li-Ling
    2025, 17(4): 1162-1171. https://doi.org/10.1111/os.14373

    Objectives: In patients with lumbar spinal stenosis (LSS), prolonged compression of the epidural venous plexus heightens the risk of bleeding and hematoma during minimally invasive surgery. While absorbable fluid gelatin, an animal protein–based hemostatic agent, is available, its effectiveness in lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD) remains debated. Our research aims to conduct a prospective randomized controlled trial to investigate the effectiveness and safety of this hemostatic material in patients undergoing LE-ULBD for LSS.

    Methods: From October 2023 to July 2024, a total of 90 patients with LSS who underwent LE-ULBD were enrolled in this study. The 90 patients were randomly divided into two groups: fluid gelatin group (45 cases, using fluid gelatin) and null-fluid gelatin group (45 cases, not using fluid gelatin). Primary outcomes included the success rate of achieving hemostasis within 3 min and symptomatic postoperative epidural hematoma (SPEH). Secondary outcomes encompassed surgical time, intraoperative blood loss, perioperative blood loss, length of stay, and complications. Independent sample t tests were used to compare continuous data. Chi-squared tests and Fisher's exact probability tests were used to analyze the categorical data.

    Results: The success rate of achieving hemostasis within 3 min (p < 0.05) was significantly higher in fluid gelatin group compared to that in the null-fluid gelatin group, and perioperative blood loss (p < 0.05) and surgical time (p < 0.05) were notably lower in the fluid gelatin group. However, there were no statistically significant differences between the two groups regarding intraoperative blood loss, length of stay, and complications, such as SPEH, allergy, and thrombus.

    Conclusion: In patients with LSS undergoing LE-ULBD surgery, using fluid gelatin can achieve rapid intraoperative hemostasis, shorten surgical time, and reduce perioperative blood loss without causing complications. Therefore, the conventional use of fluid gelatin in LE-ULBD surgery is an effective and safe strategy.

  • CLINICAL ARTICLE
    Cheng-yi Huang , Jun-bo He , Xing-Jin Wang , Ting-kui Wu , Bei-yu Wang , Jin Xu , Hao Liu
    2025, 17(4): 1172-1180. https://doi.org/10.1111/os.14374

    Objective: The principle of selecting a Zero-P implant of an appropriate height remains a topic of debate, particularly when similarly sized implants seem to appropriately fit the intervertebral space. Thus, this study compared the biomechanical performance of smaller and larger Zero-P implants within an appropriate height range with that of oversized Zero-P implants for anterior cervical discectomy and fusion (ACDF).

    Methods: A three-dimensional finite element (FE) model of the C2–C7 cervical spine was constructed and validated. The implants were categorized as smaller (6 mm), larger (7 mm), and oversized (8 mm) according to the average intervertebral height and implant specifications. Thus, the following four FE models were constructed: the intact cervical spine model (M1), the 6 mm model (M2), the 7 mm model (M3), and the 8 mm (M4) Zero-P implant C5/6 segment ACDF surgical model. Then, a pure moment of 1.0 N·m combined with a follower load of 75 N was applied at C2 to simulate flexion, extension, lateral bending, and axial rotation.

    Results: The results indicated that the maximum stress on the vertebral body, intervertebral disc, and facet joints under self-weight increased with increasing Zero-P height. Under six different loading conditions, the maximum stress on the vertebral body in the surgical segment of the M4 model was generally greater than that in the M2 and M3 models. Following an increase in the height of the implant from 6 mm to 8 mm, the maximum stress increased, and the intervertebral disc stress of both segments reached its peak in the M4 model. In the M4 model, the implant experienced the highest stress, whereas the M2 model exhibited the lowest stress on the implant under both self-weight and loading conditions. Furthermore, the stress on the posterior facet joints of the surgical segment increased with increasing Zero-P height. The range of maximum stress on the posterior facet joints for the M3 model was situated between that of the M2 and M4 models.

    Conclusion: In summary, after determining the appropriate height range for the implant in accordance with the mean height of the intervertebral space, opting for a larger size appears to be more advantageous. This approach helps maintain the height of the intervertebral space and provides greater stress, promoting a tighter fit between the upper and lower endplates and the Zero-P. This tighter fit is crucial for maintaining spinal stability, enhancing the early bony fusion rate, and potentially leading to better postoperative outcomes.

  • CLINICAL ARTICLE
    Chengqian Huang , Yingying Qin , Yizhu Huang , Xijiang Wei , Jing Zhuo , Shaofeng Wu , Jiarui Chen , Jichong Zhu , Tianyou Chen , Bin Zhang , Sitan Feng , Chenxing Zhou , Jiang Xue , Xinli Zhan , Chong Liu
    2025, 17(4): 1181-1189. https://doi.org/10.1111/os.14376

    Objective: The conventional open decompression surgery for degenerative lumbar lateral recess stenosis (DLLRS) yields definitive therapeutic outcomes; however, it confronts numerous challenges, including extensive surgical trauma and iatrogenic spinal instability. The purpose of this study is to investigate the surgical outcomes of full-endoscopic DLLRS decompression by an interlaminar approach.

    Methods: A consecutive cohort of 275 patients, including 148 males and 127 females, with an average age of 64.62 (55–82) years, with DLLRS between July 2021 and December 2022, was reviewed in this retrospective study. The involved segments were L4/5 in 126 patients and L5/S1 in 149 patients. The computed tomography (CT) and magnetic resonance imaging (MRI) of the lumbar were examined before and after surgery to evaluate the degree of decompression. The VAS score of back and leg pain and the ODI scale were recorded preoperatively, 1 day, 1, 3, 6, and 12 months after surgery, and at the last follow-up. The modified Macnab score was determined at the last follow-up. One-way analysis of variance (ANOVA) was used to compare the VAS and ODI scores of back/leg pain at various time points before and after surgery.

    Results: All of the patients underwent surgery successfully. The average duration of surgery was 84.90 min, the average blood loss was 47.33 mL, and the length of hospitalization was 3–4 (3.31 ± 0.46) days, with no nerve injury, infections, or other complications. One-way ANOVA results showed significantly improved VAS and ODI scores for back/leg pain at each time point after surgery compared to those preoperatively (p < 0.05). The mean follow-up was 23.6 ± 2.3 (range, 15–32) months; at the last follow-up, the modified Macnab was excellent in 143 patients, good in 102 patients, fair in 18 patients, and poor in 12 patients.

    Conclusion: Full-endoscopic lumbar lateral recess decompression through an interlaminar approach is a safe and effective approach for DLLRS.

  • CLINICAL ARTICLE
    Yifei Deng , Xiang Zhang , Xiaqing Sheng , Beiyu Wang , Ying Hong , Xin Rong , Chen Ding , Jingjing An , Hao Liu
    2025, 17(4): 1190-1200. https://doi.org/10.1111/os.14377

    Objective: There is a lack of research on modic change (MC) in the cervical spine, especially regarding its impact on patients following anterior cervical discectomy and fusion (ACDF). Some researchers strongly believe that MC may affect the prognosis after anterior cervical surgery. Thus, this study aimed to assess MC in patients who underwent ACDF, investigating its incidence, risk factors, and correlation with fusion success and subsidence rate.

    Methods: We retrospectively reviewed 154 patients who underwent single-level ACDF from January 2010 to December 2020, with a minimum follow-up of 12 months. Preoperative and postoperative clinical and radiological parameters were recorded at pre-operation, 1 week, 3 months after operation, and the last follow-up. The primary outcomes were the fusion rate and cage subsidence. Radiological measurements, including overall (Cobb C) and segmental cervical angle (Cobb S), anterior disc height (ADH), and posterior disc height (PDH) were also recorded. The independent t-test or Mann-Whiteny U test was used to compare continuous data, and categorical variables were assessed using the Pearson's chi-square test of Fisher's exact test. Logistic regression analysis was also adopted to distinguish corresponding factors related with the progress of MC.

    Results: Of the 154 patients, the incidence of MC was 44.2% (68/154). The group with MC showed a larger proportion of males and osteoporosis. The fusion rate of those with MC was 88.2% (60/68) while that in the non-MC group was 97.7% (84/86, p = 0.02). The MC group presented a subsidence rate of 27.9%, which was substantially higher than in the non-MC group (9.3%, p < 0.01). NDI and VAS neck was significantly higher in the MC group than in the non-MC group (p = 0.014; p = 0.039). Sex and osteoporosis were distinguished as independent factors related to MC by regression analysis (p = 0.006; p = 0.026).

    Conclusion: Preoperative MC could adversely hinder the fusion process and may increase the incidence of subsidence, affecting clinical outcomes of those underwent ACDF. Patients with MC, especially type 1 MC, are more easily suffered from neck pain than those without MC. Male sex and osteoporosis were risk factors for MC. In order to achieve a better bony fusion and avoid cage subsidence in those with MC, we encourage patients to prolong their immobilization duration with a cervical collar and precisely manage osteoporosis during the peri-operative period.

  • RESEARCH ARTICLE
    Juncheng Li , Wenrun Zhu , Jun Yang , Xinhao Niu , Han Tang , Lu Cao , Changan Guo
    2025, 17(4): 1201-1208. https://doi.org/10.1111/os.14372

    Objective: Hip and knee OA often occur successively. However, little is known about the relationship between hip and knee OA in unilateral knee OA patients. The aim of the study was to explore the correlation between unilateral knee OA and bilateral hip degeneration to determine the impact unilateral knee OA has on the severity of hip degeneration.

    Methods: This retrospective case–control study enrolled 162 patients who were presented with unilateral knee osteoarthritis and hospitalized in Zhongshan hospital, Fudan University, from January 2016 to December 2018. The severity of affected knee joint and bilateral hip joint was evaluated by using the Kellgren–Lawrence (KL) score. Variates, such as gender, age, body mass index (BMI) and Knee Society Score (KSS) at admission, were also recorded. Differences in the severity of OA between ipsilateral, contralateral hip joints and affected knee joints were accessed with chi-square tests. Single-factor and multi-factor logistic regression were applied to determine the risk factors for hip OA in patients with unilateral knee OA.

    Results: Gender have no impact on KSS, the length of disease, and BMI of patients. In contralateral hip joints, there was significant difference in the proportion of patients with severe hip degeneration (KL score ≥ 2) compared to those with mild hip degeneration (KL score < 2) when considering length of disease (p < 0.001), KSS symptom score < 70 (p = 0.001) or KSS function score (p < 0.001). The risk factors for contralateral hip degeneration of patients with unilateral knee OA include that long disease course (> 5 years) (OR 3.030 [95% CI 1.476 to 6.220]; p < 0.001), and high KSS function score (≥ 70 year) (OR 0.921 [95% CI 0.878 to 0.967]; p < 0.001), increased risk of contralateral hip degeneration of patients with unilateral knee OA.

    Conclusions: The correlation between unilateral knee OA and contralateral hip degeneration was stronger than that between unilateral knee OA and ipsilateral hip degeneration. For knee OA patients with longer course and lower KSS functional score, more attention should be paid to the degeneration process of the contralateral hip joint.

  • RESEARCH ARTICLE
    Laiwei Guo , Xiaoyun Sheng , Caijuan Dai , Xingwen Wang , Lianggong Zhao , Xiaohui Zhang , Bin Geng , Zhongcheng Liu , Rui Bai , Xiaoli Zheng , Meng Wu , Yuanjun Teng , Yayi Xia
    2025, 17(4): 1209-1219. https://doi.org/10.1111/os.14379

    Objectives: There is currently no consensus on the optimal placement of the low tibial tunnel for posterior cruciate ligament (PCL) reconstruction. This study aimed to perform the quantitative measurements of the optimal tangential low tibial-tunnel (OTLT) parameters based on 2D CT images and 3D virtual knee models and expect to provide reference data for clinical creation of the OTLT during the arthroscopic transtibial PCL reconstruction.

    Methods: This was a retrospective CT image study. A total of 101 patients between January 2018 and December 2020 were included in our study for analysis. The CT image data of included patients were imported into Mimics software to create the 3D knee models, and the OTLT for PCL reconstruction was simulated on 2D CT images and 3D knee models, respectively. With that, the distances of the tunnel's entry (ADT) and exit points (BDT) to the tibial plateau, the length of the tunnel (LT), and the angle of the tunnel (AT) were measured. Variables were compared using the independent t-test or the Mann–Whitney u test. Correlation analyses between the data and patient demographic factors were performed using the Pearson or Spearman correlation analysis. One-way ANOVA was used to compare differences among height subgroups.

    Results: The mean ADT, LT, and AT on 2D CT images were 57.96 ± 5.34 mm, 39.92 ± 5.49 mm, and 37.23° ± 4.57° respectively, smaller than the values on 3D knee models (61.86 ± 6.80 mm, 45.56 ± 4.27 mm, and 48.17° ± 6.12°, all p values < 0.001). While the mean BDT on 2D CT images was significantly larger than 3D knee models (35.28 ± 3.07 mm vs. 29.72 ± 3.00 mm, p < 0.001). The BDT showed larger in males than females, the LT showed larger in the taller group, and the AT seemed to be larger in females and shorter people (all p values < 0.05).

    Conclusion: The quantitative parameters of the OTLT based on 2D CT images and 3D knee models can be used as reference data for clinical surgeons to build an anteromedial OTLT during the arthroscopic transtibial PCL reconstruction.

  • RESEARCH ARTICLE
    Ziang Jiang , Rongshan Cheng , Dimitris Dimitriou , Yangyang Yang , Tsung-Yuan Tsai , Liao Wang
    2025, 17(4): 1220-1229. https://doi.org/10.1111/os.70000

    Objective: The traditional femoral stem is unsuitable for patients with severe proximal femoral bone defects or deformities. However, 3D-printed customized designs offer improved proximal femoral canal contact and enhance the initial stability of the femoral prosthesis. Therefore, this study aims to compare the anatomical parameters, contact parameters, and performance of the 3D-printed customized femoral short (CFS) stem with those of the traditional femoral stem following total hip arthroplasty (THA).

    Methods: An in vitro study simulating THA was performed using artificial femur models, with a 3D-printed CFS stem as the experimental group and a Trilock stem as the control group. Anatomical parameters, fitness, filling, micro-motion, and strain distribution were evaluated using artificial femoral models. Micro-motion and strain were recorded under different simulated bodyweight loading using a 3D digital image correlation measurement system.

    Results: The neck-shaft angles (NSA) and coronal femoral horizontal offset (CFHO) of the 3D-printed CFS stem (NSA: 125.22°, CFHO: 41.03 mm) were closer to those of the intact femur (NSA: 127.37°, CFHO: 43.27 mm) compare with the Trilock stem (NSA: 132.61°, CFHO: 32.98 mm). In addition, the 3D-printed CFS stem showed improved fitness at cross-sections (The top of the lesser trochanter: 6.31%, the middle of the lesser trochanter: 23.42%, the bottom of the lesser trochanter: 26.61%) and reduced micro-motion under different simulated bodyweight loads (1000: 0.043, 1375: 0.056, 2060 N: 0.061 mm).

    Conclusions: The 3D-printed CFS stem provides improved restoration of anatomical parameters, enhanced fitness, and superior biomechanical performance compared with the Trilock stem.

  • RESEARCH ARTICLE
    Feilong Sun , Haiyang Qiu , Yufei Ji , Longchao Wang , Wei Lei , Yang Zhang
    2025, 17(4): 1230-1242. https://doi.org/10.1111/os.70003

    Purpose: The biomechanics of a novel facet joint fusion device is unknown. The objective of this study is to analyze and compare the biomechanical properties of a novel facet joint fusion device integrated with oblique lateral interbody fusion (OLIF) to those of a conventional pedicle screw fixation device, employing finite element analysis.

    Methods: A comprehensive three-dimensional finite element model of the L3-S1 lumbar spine was developed and validated. Based on this model, three surgical groups were created: OLIF combined with the bilateral facet joint fusion fixation (BFJFF + OLIF), unilateral pedicle screw fixation (UPSF + OLIF), and bilateral pedicle screw fixation (BPSF + OLIF), focusing on the L4-L5 level. A torque of 7.5 Nm was applied to simulate vertebral activities under six conditions: flexion, extension, lateral bending (left and right), and axial rotation (left and right). The maximum displacement at the L4-L5 segment was then calculated. The maximum stress values were recorded at the L4-L5 interbody fusion cage and the L3-L4 and L5-S1 segments.

    Results: When compared to the other two models, the BFJFF + OLIF model exhibited the smallest maximum displacement value at the L4-L5 segment across all six working conditions. The BFJFF + OLIF model also demonstrated the lowest maximum stress value at the L4-L5 segment interbody fusion cage under flexion, as well as left and right lateral bending and axial rotation conditions when compared with the other models. However, under the extension condition at the L4-L5 interbody fusion cage, the BPSF + OLIF model showed the lowest maximum stress value. At the adjacent L3-L4 segments, the BFJFF + OLIF model registered the lowest maximum stress value during flexion and left lateral bending conditions. At L3-L4, under extension and right lateral bending conditions, the UPSF + OLIF model exhibited the lowest maximum stress value. Under left axial rotation at the L3-L4 segment, both the BFJFF + OLIF and UPSF+OLIF models demonstrated the smallest maximum stress values. Under right axial rotation at the L3-L4 segment, the BPSF + OLIF model recorded the smallest maximum stress value. Concurrently, at the L5-S1 segment, the BFJFF + OLIF model presented the lowest maximum stress value under conditions of flexion, as well as left and right lateral bending and axial rotation. In the L5-S1 segment during the extension condition, the UPSF+OLIF model exhibited the lowest maximum stress value.

    Conclusions: This study demonstrates that the novel device, when combined with OLIF, achieves 360° lumbar fusion by fusing the lumbar facet joints, thereby enhancing spinal stability post-fusion. Concurrently, stress on adjacent segments was diminished. The findings suggest that this device may serve as a novel internal fixation method. It may provide a new option for the surgical treatment of patients with low back pain in the future.

  • RESEARCH ARTICLE
    Tianqi Fan , Lin Shi , Xuan Peng , Menghao Wu , Lingjia Yu , Bin Zhu
    2025, 17(4): 1243-1254. https://doi.org/10.1111/os.70008

    Objective: Spinal full-endoscopic surgery is a challenging technique with a steep learning curve, limited by inadequate training models and the shortcomings of cadaver-based training. To address this, we propose a high-simulation training system using VR/AR and magneto-optical navigation technology to enhance skill development and reduce the learning curve.

    Methods: A new simulation training system for spinal full-endoscopic surgery was established, which was conducted by using the data of Chinese Digital Human with medical image parameters for the three-dimensional (3D) reconstruction, as well as integrating the technical advantages of VR/AR, 3D printing, and magneto-optical navigation technology.

    Results: Based on the original dataset of Chinese digital humans and clinical medical imaging processing, the data model was obtained and then the 3D printing engineering model was created. The simulation perspective filming technology, joint process shaping and cutting technology, and tube placement technology have been constructed, based on the combination of VR/AR under optical navigation. Based on electromagnetic tracking, a microscopic anatomical simulation using preorder optical navigation has been designed. Finally, a physical simulation model based on the clinical reality of flocculent behavior was constructed. As a simulator for spinal endoscopic surgery training, it was tested during an advanced endoscopic training course. Moreover, 17 out of 20 novices (85%) met the surgical standards by the end of the final simulation training session.

    Conclusion: We present a high simulation training system based on the combination of VR/AR and magneto-optical navigation for spinal full-endoscopic surgery. The model may be used by surgeons starting with spinal endoscopy and should be considered a comparable and sufficiently realistic tool to train key operation steps to reduce the learning curve.

  • OPERATIVE TECHNIQUE
    Zhou-Feng Song , Wei-Qiang Zhao , Zeng-Li Zhang , Jie-Feng Huang
    2025, 17(4): 1255-1264. https://doi.org/10.1111/os.70005

    Objective: Duckerley type IIIB distal humerus fractures are rare and complex injuries that pose significant challenges in both diagnosis and treatment. Currently, no consensus exists on the fixation method, with existing approaches often struggling to handle small fragments and associated with issues like elbow instability. The purpose of this study is to evaluate the surgical outcomes of submerged Kirschner wires combined with plate or submerged screw fixation technique for the treatment of Duckerley type IIIB distal humerus fractures.

    Methods: A retrospective analysis was conducted on 10 patients with Duckerley type IIIB distal humerus fractures who were treated at our hospital from February 2017 to April 2021. The treatment involved applying buried Kirschner wires combined with microplate or buried screw fixation technique through the olecranon osteotomy approach. The study included six males and four females, with a mean age of 51.4 ± 15.34 years (ranging from 22 to 69 years). During the follow-up, the elbow range of motion, Mayo Elbow Performance Score (MEPS), American Shoulder and Elbow Surgeons (ASES) score, and complications were assessed.

    Results: All 10 patients received regular clinical and imaging follow-up for a mean of 39.7 ± 8.8 months (range: 25–50 months). Postoperative incision healing was good for all patients, and no neurovascular injuries were noted. Two patients developed elbow pain. At the last follow-up before the internal fixation removal operation (9.6 ± 1.9 months), X-ray and CT findings confirmed bony healing, and no internal fixation loosening and breakage occurred in any of the patients, except for one case in which there was displacement of the Kirschner wires. The mean range of motion of the elbow before the internal fixation removal operation was extension 15.0° ± 21.6°, flexion 129.5° ± 28.1°, pronation 83.0° ± 9.2°, and supination 81.5° ± 8.0°. The MEPS score was 83.0 ± 8.3, and the ASES was 83.6 ± 7.8. At the last follow-up, the mean range of motion of the elbow was extension 10.0° ± 21.9°, flexion 133.5° ± 16.0°, pronation 88.0° ± 11.2°, and supination 85.0° ± 9.5°. The MEPS score was 84.6 ± 7.6, and the ASES was 84.1 ± 7.4.

    Conclusions: The treatment of Duckerley type IIIB low distal humerus fractures using submerged Kirschner wires combined with plate or submerged screw fixation technique has satisfactory advantages in terms of fracture reduction, maintenance of the position of internal fixation, and postoperative recovery.

  • CASE REPORT
    Zhenlei Liu , Yaobin Wang , Lei Zhang , Shanhang Jia , He Wang , Lei Cheng , Fengzeng Jian , Kai Wang , Hao Wu
    2025, 17(4): 1265-1274. https://doi.org/10.1111/os.14366

    Background: Iatrogenic cervical kyphosis (ICK) often requires complex anterior and posterior correction, which is associated with multiple complications. Consequently, there is a need to investigate alternative treatment approaches that streamline the operative process and markedly diminish postoperative complications. This study, therefore, aimed to evaluate the feasibility and efficacy of a single-stage anterior controllable antedisplacement fusion (ACAF) in revision surgeries for ICK.

    Methods: A retrospective review was conducted on three ICK cases treated with the ACAF technique in our department from December 2023 to January 2024. The cohort comprised two females and one male. The medical records, symptoms, signs, imaging studies, and 3-month postoperative follow-up data were analyzed to preliminarily evaluate the surgery's feasibility and efficacy.

    Results: The mean operative time was 222.0 ± 67.5 min, with an average blood loss of 83.3 ± 28.9 mL and an average hospital stay of 11.7 ± 2.9 days. No patient experienced severe complications, such as neurological damage, during surgery. Postoperatively, two patients experienced transient respiratory distress within 2–5 days, managed with low-dose methylprednisolone (80 mg daily) and supplemental oxygen via nasal cannula. At the 3-month follow-up, all patients showed significant symptom improvement and increased cervical Japanese Orthopedic Association scores. Radiographic assessments, including X-rays and computed tomography scans, demonstrated marked improvements in cervical curvature without evidence of screw loosening. Magnetic resonance imaging indicated significant dural sac expansion and alleviation of spinal cord compression.

    Conclusion: The ACAF technique effectively corrects ICK, offering advantages such as reduced intraoperative blood loss, fewer complications, and shorter operative and hospitalization times compared to traditional combined anterior–posterior corrective approaches. It presents an effective alternative for surgeons performing revision corrective surgery for ICK.