To explore the impact of different lamina formation ranges on the biomechanical stability of L 5, S 1 in spine surgery with unilateral biportal endoscopy (UBE), providing a theoretical basis for optimizing clinical surgical plans. A complete lumbar finite element model (M0) was constructed based on CT data of L 3-S 1 from a healthy male volunteer. Four different UBE surgical models with varying lamina formation ranges (M1-M4) were simulated. M1 model involved initial laminectomy with essentially intact facets; M2 model involved minor facet resection (5-10 mm from the inferior facet joint surface); M3 model involved greater facet resection with partial laminectomy depth >10 mm; M4 model involved complete facet resection to simulate extreme decompression. Finite element analysis was performed to assess the range of motion (ROM), maximum displacement, and maximum von Mises stress of the vertebrae under different physiological activities (flexion, extension, left/right bending, and left/right rotation), as well as the maximum displacement and maximum von Mises stress of the intervertebral disc, and the maximum von Mises stress of right facet joints under left rotation and right bending. With increasing forming range, the ROM of the vertebrae in flexion showed a slight increase (0.32° higher in M4 model than in M0 model), and the maximum displacement generally increased in all motion states. For the intervertebral disc, the maximum von Mises stress and displacement increased mildly in flexion and left rotation, which were approximately 17% and 12% higher in M3 and M4 models than in M0 model, respectively. And the biomechanical parameters changed little among different models under extension, right rotation, and left bending. The von Mises stress of the right facet joint increased stepwise with forming range during left rotation (about 57% higher in M3 model than in M0 model) and was higher in all surgical models than in M0 model during right bending. Expanding the lamina formation range in UBE spine surgery can lead to reduced stability in flexion and left rotation activities at L 5, S 1, increasing the mechanical load on the intervertebral disc and facet joints. Clinically, under the premise of achieving adequate decompression, prioritizing a forming range corresponding to the lower transverse width partition (25%-50%) may better balance decompression efficacy with biomechanical stability of the L 5, S 1 segment, thereby reducing the potential risk of long-term degeneration caused by excessive bony resection.

To investigate the short-term effectiveness of endoscopic lumbar discectomy combined with annular suturing in treatment of lumbar disc herniation (LDH). A retrospective analysis was performed on the clinical data of 79 patients diagnosed with single-level LDH and admitted between February 2024 and December 2024, who met the selection criteria. Of these patients, 39 underwent a combined endoscopic discectomy with annular suturing (combined group), while 40 received endoscopic discectomy alone (control group). No significant difference was found between groups ( P>0.05) in terms of gender, age, disease duration, surgical level, or baseline measurements, including preoperative visual analogue scale (VAS) scores for back and leg pain, Oswestry disability index (ODI), and intervertebral disc height. The study evaluated and compared several parameters between groups, including operation time, intraoperative blood loss, postoperative complications, VAS scores for back and leg pain, ODI, intervertebral disc height at 1, 3, 6, and 12 months postoperatively, and recurrence during follow-up. The combined group experienced longer operation time compared to the control group ( P<0.05). However, there was no significant difference in intraoperative blood loss between groups ( P>0.05). Postoperative complications, such as intervertebral space infection, nerve root injury, cerebrospinal fluid leakage, or deep vein thrombosis of the lower limbs, were absent in both groups. All patients were followed up for 12 months. After operation, the ODI and VAS scores for back and leg pain showed gradual improvement in both groups ( P<0.05), yet no significant difference was observed between groups at different time points ( P>0.05). Imaging follow-up indicated a reduction in intervertebral disc height postoperatively in both groups relative to preoperative measurements ( P<0.05). No significant difference in disc height between groups was noted at 1 and 3 months ( P>0.05). At 6 and 12 months, the combined group demonstrated significantly greater disc height compared to the control group ( P<0.05). During follow-up, recurrence was observed in 1 case (2.56%) of combined group and in 3 cases (7.50%) of control group, showing no significant difference in the incidence of recurrence between groups ( P>0.05). In comparison to simple lumbar discectomy, endoscopic lumbar discectomy with annular suturing for LDH not only yields comparable short-term effectiveness but also significantly mitigates the postoperative intervertebral disc height collapse, preserves spinal stability, and decelerates the progression of disc degeneration.

To evaluate effectiveness of three-dimensional (3D) printed patient-specific cutting guides (PSCGs) in Cole midfoot osteotomy for treatment of rigid pes cavus deformity associated with Charcot-Marie-Tooth (CMT) disease, and to analyze learning curve for PSCGs-assisted surgery. A retrospective analysis was conducted of 20 patients (40 feet) with rigid pes cavus deformity associated with CMT who were admitted between March 2021 and July 2023 and met the inclusion criteria. The cohort comprised 13 men and 7 women, with ages ranging from 17 to 62 years (mean, 37.3 years). All patients underwent whole-genome sequencing, which identified 17 patients with CMT type 1 and 3 patients with CMT type 2. Preoperatively, 3D models of bilateral feet were reconstructed based on CT data, and PSCGs were designed and fabricated accordingly. All patients underwent a Cole midfoot osteotomy assisted by the guides. Operation time, number of intraoperative fluoroscopic exposures, and intraoperative complications were recorded. Pre- and post-operative outcomes were compared using the visual analogue scale (VAS) score for pain, the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, and domain scores of the 36-Item Short Form Health Survey (SF-36), as well as radiographic parameters including the Meary's angle, Pitch angle, talo-first metatarsal angle (T1MT), talocalcaneal angle (TCA), and Djian-Annonier angle, to assess the corrective effect of the osteotomy. A modified cumulative sum analysis was performed to evaluate the learning curve for PSCGs-assisted surgery. All procedures in the 20 patients (40 feet) were completed successfully, with no cases of massive hemorrhage or injury to critical neurovascular or tendinous structures. The operation time ranged from 63 to 129 minutes (mean, 82.9 minutes), and fluoroscopy was performed 2-11 times (mean, 4.7 times). Postoperatively, 1 patient (1 foot) developed a mild superficial surgical-site infection, which resolved with symptomatic treatment; no deep infections occurred. All patients were followed up 8-43 months (mean, 17 months). At last follow-up, the AOFAS ankle-hindfoot score and all domain scores of the SF-36 were significantly higher than preoperative values, and the VAS score, the Meary's angle, T1MT, TCA, and Djian-Annonier angle significantly decreased, Pitch angle significantly increased ( P<0.05). The imaging confirmed osteotomy union in all feet, and no fixation-related complications was observed. Learning-curve analysis indicated that both operation time and fluoroscopy usage plateaued after the 13th case, suggesting stabilization of surgical performance from that point onward. The use of PSCGs during Cole midfoot osteotomy enables precise and efficient correction of complex midfoot deformities while significantly reducing intraoperative fluoroscopic exposure. Moreover, this technique appears to have a short learning-curve and good reproducibility, which may facilitate its broader adoption in clinical practice.

To compare the analgesic efficacy and safety of liposomal bupivacaine (LB) versus ropivacaine for surgical incision local anesthesia after artificial intelligence (AI)-assisted direct anterior approach (DAA) total hip arthroplasty (THA). A prospective randomized controlled study was conducted. A total of 120 patients who underwent AI-assisted DAA-THA between March 2024 and January 2025 were enrolled and randomly assigned to the LB group ( n=60) or the "cocktail" group ( n=60). Patients in the LB group received an intraoperative injection of LB 266 mg (diluted to 100 mL) around the incision, whereas those in the "cocktail" group received a mixture of ropivacaine 200 mg, compound betamethasone 1 mL, and epinephrine 0.5 mg (diluted to 100 mL). Resting and active visual analogue scale (VAS) scores were recorded at 6, 12, 24, 36, 48, 60, and 72 hours and at 2 and 4 weeks postoperatively. Changes in Pain Catastrophizing Scale (PCS) score, Harris hip score, and hip flexion and abduction range of motion at 4 weeks postoperatively relative to preoperative values were assessed. In addition, operation time, incision length, total postoperative oral morphine consumption, time to first ambulation, length of hospital stay, and complications within 72 hours after surgery were recorded and compared between the two groups. There was no significant difference between the two groups in incision length, time to first ambulation, length of hospital stay, or total postoperative oral morphine consumption ( P>0.05). Operation time was significantly longer in the LB group than in the "cocktail" group ( P<0.05). All patients were followed up for 6 months postoperatively. Both resting and active VAS scores decreased over time in the two groups ( P<0.05). Intergroup comparison showed that resting and active VAS scores at 60 and 72 hours postoperatively were significantly lower in the LB group than in the "cocktail" group ( P<0.05), whereas no significant difference was observed at other time points ( P>0.05). There was no significant difference between the two groups in the changes in PCS score, Harris Hip Score, or hip range of motion at 4 weeks postoperatively ( P>0.05). In the LB group, nausea and vomiting occurred in 3 cases, significant blood glucose fluctuations in 2 cases, superficial incision infection in 1 case, and local hematoma in 1 case; the corresponding numbers in the "cocktail" group were 5, 4, 0, and 1 case, respectively. No significant difference was observed between the two groups in the incidence of these complications ( P>0.05). No local allergic reactions, deep vein thrombosis, significant blood pressure fluctuations, deep incision infection, skin necrosis, or pulmonary embolism occurred in either group. At last follow-up, satisfaction rates for analgesic efficacy and hip function both exceeded 90% in the two groups, with no significant difference between groups ( P>0.05). In AI-assisted DAA-THA, local infiltration anesthesia with LB provides analgesic efficacy comparable to that of the "cocktail" therapy during the early postoperative period (within 48 hours). Although VAS scores were slightly lower in the LB group at 60-72 hours postoperatively, the difference was small and the clinical benefit was limited. No significant difference was observed between the two groups in opioid consumption, complication rates, PCS scores, or postoperative functional recovery. In the context of AI-assisted DAA-THA, the clinical advantage of LB over the conventional "cocktail" therapy appears limited.

To investigate the impact of spontaneous facet joint fusion (SFJF) on lumbar motion function following isolated posterior internal fixation for lumbar burst fractures, characterize SFJF radiographically, and explore the indications for implant removal. Patients who underwent implant removal after posterior internal fixation for lumbar burst fractures between January 2018 and September 2024 were retrospectively reviewed. A total of 137 patients (330 segments) met the selection criteria and were enrolled, including 89 males and 48 females, with a median age of 50.0 years (range, 18-71 years). There were 98 patients with two segments, 22 with three segments, and 17 with four segments. Baseline characteristics were included, such as gender, age, AO fracture type, and visual analogue scale (VAS) score for back pain and Oswestry disability index (ODI) at last follow-up. Based on radiographic assessment, facet joint (FJ) fusion was graded as grade 1 (non-fusion), grade 2 (SFJF), or grade 3 (SFJF). Segmental range of motion (ROM) was measured, motion loss rate was calculated, and functional motion status was determined. Intergroup comparisons were performed for baseline characteristics and radiographic parameters. Factors influencing SFJF were analyzed, and the segmental distribution, temporal pattern of SFJF, and its impact on segmental stability were evaluated. Postoperative CT revealed that the FJ fusion were rated as grade 1 in 53 patients (190 segments, 57.6%), grade 2 in 49 patients (86 segments, 26.1%), and grade 3 in 35 patients (54 segments, 16.4%). Accordingly, 84 patients (140 segments, 42.4%) were classified as SFJF. Patients with SFJF were younger and had a higher proportion of males, showing significant differences ( P<0.05). However, there was no significant difference in AO fracture classification between patients with and without SFJF ( P>0.05). At last follow-up, the SFJF patients exhibited higher VAS scores ( P<0.05), but no significant difference was observed in ODI ( P>0.05). At last follow-up, no significant difference was observed in the distribution of SFJF grades among the 330 segments ( P>0.05). The incidence of SFJF increased significantly from 17.9% at 3 months to 39.7% at 6 months postoperatively ( P<0.05), with no further significant increase at last follow-up (42.4%, P>0.05). Among SFJF patients with flexion-extension X-ray films, 45 patients with 115 segments were analyzed, including 75 SFJF segments (47 grade 2 and 28 grade 3). Grade 2 and grade 3 segments showed significantly lower ROM than grade 1 segments ( P<0.05). Compared with grade 2 segments, grade 3 segments exhibited significantly lower ROM, reduced motion function, and higher motion loss rate ( P<0.05). The incidence of SFJF following posterior internal fixation for lumbar burst fractures is high, with most fusion processes occurring within the first 6 months after operation. Segmental motion function decreases significantly with increasing fusion grade. Incorporating SFJF assessment into the decision-making process for implant removal in these patients is recommended.

To investigate the effect of preoperative lower-limb muscle strength on perioperative blood loss, postoperative pain, and functional recovery in patients undergoing total knee arthroplasty (TKA). A retrospective analysis was conducted on the clinical data of 380 patients who underwent TKA and met the selection criteria between February 2023 and December 2024. Based on the gender-specific median of standardized preoperative lower-limb extensor isokinetic muscle strength (IMS), the patients were divided into a low-extensor strength group and a high-extensor strength group, with 190 cases in each group. The following data of the two groups were collected and compared, including age, gender, body mass index, comorbidities, surgical side, length of hospital stay, Kellgren-Lawrence grade, perioperative parameters [including hematocrit (Hct) and hemoglobin (Hb) levels within 1 week preoperatively and 2-3 days postoperatively, with the calculation of Hct loss and Hb loss (the difference between the pre- and post-operative measurements), and whether intraoperative allogeneic blood transfusion was performed], preoperative knee flexion and extension IMS, 5-time sit-to-stand (5-STS) test within 2 weeks preoperatively, as well as visual analogue scale (VAS) score for pain and active range of motion (AROM) within 2 weeks preoperatively and 1 day postoperatively. Pearson correlation analysis was used to analyze the correlation between preoperative lower-limb extensor IMS and TBL. Through multiple linear regression analysis, the effect of IMS on TBL was further explored after adjusting for confounding factors such as age, body mass index, hypertension, diabetes mellitus, coronary atherosclerotic heart disease, and chronic obstructive pulmonary disease. There was no significant difference between the two groups in age, gender, body mass index, surgical side, Kellgren-Lawrence grade, comorbidities, length of hospital stay, preoperative Hct and Hb levels, intraoperative allogeneic blood transfusion rate, and changes in VAS scores ( P>0.05). The high-extensor strength group was superior to the low-extensor strength group in preoperative VAS scores, AROM, 5-STS, as well as postoperative Hct and Hb loss, and the changes of AROM and TBL were less than those in the low-extensor strength group, with all differences being significant ( P<0.05). Pearson correlation analysis showed a negative correlation between preoperative lower-limb extensor IMS and TBL ( r=-0.460, P=0.043). Multiple linear regression analysis showed that after adjustment, a lower TBL was associated with a higher preoperative lower-limb extensor IMS. Specifically, for every 1 N·m increase in preoperative lower-limb extensor IMS, TBL decreased by 9.973 mL. TBL was not significantly affected by other factors such as age, body mass index, and comorbidities. Higher preoperative lower-limb muscle strength is associated with reduced intraoperative blood loss during TKA and improved postoperative pain relief and functional recovery. These findings highlight the critical role of preoperative muscle strength management, providing scientific evidence for designing standardized postoperative rehabilitation protocols and offering guidance for optimizing surgical timing to maximize recovery outcomes.

To investigate the morphological characteristics of the os subfibulare (OSF) and evaluate its clinical association with chronic ankle instability (CAI). Imaging data of 130 patients with OSF between January 2015 and August 2025 were retrospectively analyzed, including 82 males and 48 females with a mean age of 30.6 years (range, 10-80 years). Patients were divided into CAI group ( n=74) and non-CAI group ( n=56). X-ray films were used for screening, while CT images were used to measure the parameters related to the shape and spatial location of the OSF, including the maximum diameter, maximum area, distance from the OSF center to the fibular tip, distance from OSF to the talus, and the angle between the OSF and the fibular long axis. OSFs were classified as regular or irregular. MRI categorized OSF location into three zones based on ligament attachment sites: zone Ⅰ [anterior talofibular ligament (ATFL)], zone Ⅱ (calcaneofibular ligament), and zone Ⅲ (posterior talofibular ligament). Bone interface fluid signal, bone marrow edema, and ATFL injury were recorded. The patients with CAI were stratified and analyzed to compare the differences in the location, shape and spatial localization of the OSF (the maximum diameter of OSF, the distance from the OSF center to the fibular tip, the angle between the OSF and the fibular long axis) and MRI signs between different genders and between different affected sides. CT measurements showed that, compared with the non-CAI group, the CAI group exhibited differences in spatial localization of the OSF. The distance from the OSF center to the fibular tip was significantly greater in the CAI group ( P<0.05), whereas the distance from OSF to the talus, and the angle between the OSF and the fibular long axis showed no significant difference ( P>0.05). Regarding morphology and size, the maximum diameter of OSF was significantly larger in the CAI group ( P<0.05), while no significant difference was found in maximum area of OSF or morphological type ( P>0.05). MRI findings showed that OSFs were predominantly located in zone Ⅰ in both groups, followed by zones Ⅱ and Ⅲ. There was no significant difference in distribution between groups ( P>0.05). The incidences of bone marrow edema, bone interface fluid signal, and ATFL injury were significantly higher in the CAI group than in the non-CAI group ( P<0.05). Within the CAI group, no significant difference was observed between genders or affected sides in terms of OSF location, morphology, spatial parameters, or MRI findings ( P>0.05). Patients with CAI showed a larger maximum OSF diameter and a greater distance from the OSF center to the fibular tip, and were more frequently accompanied by MRI findings such as bone marrow edema, bone interface fluid signal, and ATFL injury. These imaging characteristics may help evaluate the relationship between OSF and CAI from an imaging perspective.

To investigate the short-term effectiveness of high tibial osteotomy (HTO) for treatment of middle aged and older populations with varus knee combined with medial meniscus posterior root tear (MMPRT), and to evaluate the biomechanical changes in the knee joint after operation based on finite element analysis. A retrospective analysis of clinical data was conducted on 35 patients (35 knees) admitted between June 2021 and October 2023, who met the inclusion criteria for varus knee combined with MMPRT. There were 17 males and 18 females with a mean age of 59.2 years (range, 48-65 years). Open wedge HTO was performed to correct the alignment in all patients. X-ray films and MRI were conducted before operation and at 3, 6, and 12 months after operation to assess changes in lower limb alignment and joint structure. And the femorotibial angle, medial proximal tibial angle (MPTA), posterior tibial slope angle (PTSA), weight-bearing line ratio (WBLR), as well as the Lysholm score, Hospital for Special Surgery (HSS) score, and visual analogue scale (VAS) score for pain were compared between pre- and post-operation. Finite element models were reconstructed based on knee CT data from a healthy volunteer to simulate changes in stress distribution at the knee joint before and after HTO, and to analyze postoperative mechanical improvement characteristics. All 35 patients underwent successful operations. Postoperatively, 3 cases of incisional fat liquefaction and 2 cases of mild superficial wound infection occurred; no complication such as deep vein thrombosis of the lower extremities, severe infection, or neurovascular injury was observed. All patients were followed up 12-14 months (mean, 13.0 months). Imaging reexamination revealed that all osteotomies had achieved radiographic union, with no complication such as osteotomy loss, significant collapse, or plate fracture. At 12 months after operation, the femorotibial angle, MPTA, WBLR, and PTSA were all significantly higher than preoperative levels ( P<0.05). Compared with preoperative values, the Lysholm score and HSS score gradually increased, while the VAS score decreased at 3, 6, and 12 months, with significant differences between different time points ( P<0.05). Finite element analysis showed that the stress distribution in the medial and lateral compartments of the knee joint tended toward equilibrium after HTO. Medial cartilage contact stress decreased by approximately 40% compared to preoperative levels, and stress concentration in the medial meniscus was significantly reduced. HTO can significantly alleviate knee pain in middle aged and older populations with varus knee combined with MMPRT, improve the distribution of knee joint forces, and promote the recovery of joint function.

To investigate the impact of the surgeon's dominant hand-side on the operational efficiency and safety of primary lumbar discectomy under unilateral biportal endoscopy (UBE). A prospective cohort study was conducted in 60 patients with single-level lumbar disc herniation who underwent UBE lumbar discectomy between August 2024 and August 2025 by the same right-handed surgeon, including 30 patients with non-dominant (right approach) (non-matched group) and 30 patients with dominant (left approach) (matched group). No significant difference was observed between the two groups in baseline data including gender, age, body mass index, herniated segment distribution, disease duration, and preoperative visual analogue scale (VAS) score and Oswestry disability index (ODI) ( P>0.05). The total operation time, core endoscopic operation time, intraoperative blood loss, and related complications were recorded and compared between the two groups. A self-developed surgeon's operational fluency assessment score was used for auxiliary subjective evaluation. VAS score and ODI were used to assess pain and functional improvement preoperatively and at 1 and 3 months postoperatively. The modified MacNab criteria was used to evaluate overall surgical outcomes at 3 months postoperatively. There was no significant difference in the total operation time and intraoperative blood loss between the two groups ( P>0.05). The core endoscopic operation time of the matched group was significantly shorter than that of the non-matched group, and the operational fluency assessment score of the matched group was significantly higher than that of the non-matched group ( P<0.05). All patients were followed up 3-6 months, with an average of 4.2 months. Complications occurred in 2 cases (6.7%) in the matched group, including 1 case of dural tear and 1 case of postoperative transient nerve root palsy, and 1 case (3.3%) in the non-matched group, which was postoperative epidural hematoma. There was no significant difference in the incidence of complications between the two groups ( P>0.05). The VAS scores and ODI of the two groups decreased at 1 and 3 months after operation, and improved further at 3 months after operation compared with 1 month after operation, and the differences were significant ( P<0.05), but there was no significant difference between the two groups after operation ( P>0.05). Modified MacNab standard was used to evaluate the curative effect at 3 months after operation, and there was no significant difference in the evaluation grade and excellent and good rate between the two groups ( P>0.05). Consistency between the surgeon's dominant hand side and the surgical approach side significantly improves core endoscopic operational efficiency and surgical fluency in UBE lumbar discectomy, without compromising clinical efficacy or safety. It is suggested that this matching factor should be prioritized in surgical scheduling and beginner training to optimize the operative experience and shorten the learning curve.