Abstract:[Objective] To compare the clinical results of the dorsal branch of digital artery flap (DBDA) and dorsal metacarpal artery return branch flap (DMARB) transfer for the emergency repair of the palmar soft tissue defect on the middle and distal segment of the fin- ger. [Methods] From May 2015 to August 2020, 46 patients received surgical repair of soft tissue defect on the middle and distal segment of the 2 to 5 fingers. According to doctor- patient communication, 25 patients received DBDA flap, while the remaining 21 patient had wound repaired with the DMARB flap. The perioperative conditions and follow-up results of the two groups were compared. [Results] All the patients in both groups had operation performed smoothly without serious complications. The donor area was closed by skin grafting in the DBDA group, while mainly by direct suture in the DMARB group, and the former was significantly inferior to the latter (P＜0.05). Howev- er, there were no significant differences in operation time, flap survival area 1 week after operation, incision healing grade in donor area, su- ture removal time and hospital stay between the two groups (P＞0.05). All patients in both groups were followed up for 9 to 20 months, with an average of (13.6±2.4) months. At the last follow-up, the DBDA group proved significantly superior to the DMARB group in terms of stat- ic two-point recognition and appearance satisfaction scores (P＜0.05), despite of the fact that there was no statistical significance in total ac- tive motion (TAM) between the two groups (P＞0.05). [Conclusion] Both of the two types of flap transfer do effectively repair the soft tissue defects on the palmar side of the middle and distal segments of the finger. By contrast, the DBDA flap achieves better feeling and more cos- metic appearance than the DMARB flap.

Abstract:[Objective] To compare the clinical results of selective bundle reconstruction with the remnant bundle preservation (SBRRP) versus standard single-bundle reconstruction (SSBR) for partial anterior cruciate ligament (ACL) tear. [Methods] A retrospective study was conducted on 36 patients who received arthroscopic ACL reconstruction for partial ACL tear in our hospital from October 2016 to Janu- ary 2020. Of them, 17 consecutive patients received SSBR from October 2016 to January 2018, whereas 19 consecutive patients received SNR-RP from February 2018 to January 2020. The documents regarding perioperative period, follow-up and images were compared be- tween the two groups. [Results] All patients in both groups had corresponding ACL reconstructions performed smoothly, without significant differences in terms of operation time, combined meniscus injury and cartilage injury, incision healing grade, hospital duration between the two groups (P＞0.05). All the patients were followed up for (32.8±6.5) months on a mean. The SBR-RP proved significantly superior to the SSBR in terms of the Lysholm and IKDC scores 12 months after surgery (P＜0.05), regardless of that there were no significant differences in side-side difference of relaxation, pivot shift test, Lachman test, Lysholm score and IKDC score between the two groups 24 months postoper- atively (P＞0.05). The patients in the SBR-RP group resumed sports activity significantly earlier than those in the SSBR group (P＜0.05). Up to the last follow-up the rate of returning to exercise was 47.4% (9/19) in the SBR-RP group, while 47.1% (8/17) in the SSBR group, which was not significantly different between them (P＞0.05). On imaging, there was no significant difference in the excellent and good rate of bone tunnel placement between the two groups (P＞0.05), moreover, there was no significant difference in the incidence of bone tunnel enlarge- ment between the two groups 12 months after surgery (P＞0.05). [Conclusion] Selective bundle reconstruction with remnant bundle preser- vation is a better choice for partial ACL tear with better early functional recovery and shorter time to return exercise over the standard sin- gle bundle reconstruction.

Abstract:[Objective] To evaluate the clinical outcomes of manipulation under anesthesia (MUA) combined with isokinetic muscle strength exercise for frozen shoulder. [Methods] A retrospective study was performed on 60 patients who received MUA therapy for frozen shoulder in our hospitals from October 2017 to February 2019. According to doctor-patient communication prior to treatment, 30 patients received isokinetic exercises after treatment of MUA (isokinetic group), while the other 30 patients received routine rehabilitation exercises after treatment of MUA (routine group). The documents regarding to treatment period, follow-up and ISOMED2000 examination were com- pared between the two groups. [Results] All the patients in both groups had treatment finished successfully without serious complications. The isokinetic group had significantly shorter treatment period than the routine group [(84.6±8.3) days vs (103.9±28.3) days, P＜0.05], de- spite the fact that former had significantly higher treatment cost than the latter [(2 760.7±134.2) yuan vs (2 355.2±401.9) yuan, P＜0.05]. The VAS scores for pain decreased significantly over time in both groups (P＜0.05), which in the the isokinetic group was significantly better than that of the routine group 2 and 4 weeks after treatment (P＜0.05). In addition, the intensity of analgesic used in the isokinetic group was significantly lower than that in the routine group (P＜0.05). All patients were followed up for a mean of (34.5±5.9) months. The ConstantMurley scores, as well as shoulder abduction, flexion, and posterior extension range of motion (ROM) increased significantly over time in both groups (P＜0.05). At the last follow-up, the isokinetic group proved significantly superior to the routine group in terms of constant-Mur- ley scores, abductor, flexion, and extension ROMs [(91.4±4.2) vs (88.3±4.6); (165.8±9.6)° vs (149.7±14.8)°; (171.1± 8.3)° vs (159.2±12.6)°; and (49.7±5.6)° vs (40.0±4.7)°, P＜0.05]. In terms of the ISOMED2000 test, the peak torque (PT) of 60°/s abduction, 60°/s flexion, 60°/s ex- tension, 120°/s abduction, 120°/s flexion, 120°/s extension, 180°/s abduction, 180°/s flexion, and 180°/s extension significantly increased in both groups at the latest follow-up compared with those before treatment (P＜0.05). Although there were no significant differences in the above measures between the two groups before treatment, the isokinetic group was significantly better than the routine group at the latest fol- low-up (P＜0.05). [Conclusion] MUA combined with isokinetic exercises does significantly improve the therapeutic effect for frozen shoul- der, which more effectively relieve shoulder pain, increase joint motion and enhance shoulder strength.

Abstract:[Objective] To compare the clinical efficacy of microscopy-assisted versus direct-vision decompression and instrumented fusion for lower cervical fracture and dislocation complicated with spinal cord injury. [Methods] From January 2016 to January 2018, 74 patients with lower cervical spine fracture and dislocation complicated with spinal cord injury were enrolled in this study. Of them, 40 pa- tients were treated with microscopic decompression and fusion fixation (the MS group), while the remaining 34 patients received convention- al direct-vision decompression and fusion fixation (the DV group). The perioperative period, follow-up and imaging data were compared be- tween the two groups. [Results] All patients in both groups had operation completed successfully. The MS group proved significantly superi- or to the DV group in terms of intraoperative blood loss, incision length, intraoperative fluoroscopy times, postoperative ambulation time and hospital stay (P＜0.05), but the former consumed significantly longer operation time than the latter (P＜0.05). In addition, the MS group had significantly lower incidence of early complications than the DV group (P＜0.05). With time of follow-up lasted for (3.1±0.5) years, VAS and JOA scores, as well as Frankel index, improved significantly in both groups (P＜0.05). However, there was no significant difference in the above items between the two groups at any corresponding time points (P＞0.05), furthermore, there was no a significant difference in the time to resume full-weight bearing activity between the two groups (P＞0.05). Radiographically, the ratio of anterior height of injured vertebrae significantly increased (P＜0.05), whereas the local kyphotic Cobb angle significantly decreased in both groups at 3 months after operation and at the last follow-up compared with those preoperatively (P＜0.05), which proved not statistically significant between the two groups at any corresponding time points (P＞0.05). [Conclusion] Microscopy-assisted decompression and instrumented fusion for lower cervical frac- ture and dislocation accompanied with spinal cord injury have the advantages of less trauma and lower incidence of postoperative complica- tions.

Abstract:[Objective] To systematically compare the clinical outcomes of total ankle arthroplasty (TAA) versus ankle arthrodesis (AA) in the treatment of traumatic ankle arthritis. [Methods] The articles in Chinese and English on TAA and AA for traumatic ankle arthritis at home and abroad were searched in databases, including PubMed, Cochrane Library, Embase, CNKI, VIP and Wanfang, from creating to Oc- tober 2022. After the papers were selected by screening to meet the inclusion criteria and bias risk evaluation, data were extracted for a me- ta-analysis using RevMan5.3 software. [Results] A total of 8 articles were included in this study, including 4 retrospective cohort studies and 4 randomized controlled trials with a total of 481 cases, 253 in the TAA group and 228 in the AA group. As results of meta-analysis, the TAA group consumed significantly shorter operation time than the AA group (MD=-51.88, 95%CI -98.18~-5.58, P=0.03), the former had significantly higher Kofoed score than the latter (MD=6.60, 95%CI 3.72~9.47, P＜0.01), the TAA group proved significantly less postop- erative claudication than the AA group (MD=0.17, 95%CI 0.05~0.55, P＜0.01), whereas the TAA group got significantly more number of postoperative revisions than the AA group (MD=2.73, 95%CI 1.05~7.14, P=0.04). However, there were no significant differences between the two groups in terms of AOFAS score (MD=3.47, 95%CI -2.90~9.84, P=0.29), VAS score (MD=-0.90, 95%CI -1.95~0.15, P=0.09), postoperative complications (MD=3.77, 95%CI -0.42~33.93, P=0.24) and intraoperative blood loss (MD=49.21, 95%CI -9.04~107.46, P= 0.10). [Conclusion] Compared with the AA group, the TAA group has the advantages of better postoperative feeling and faster functional re- covery of ankle joint, but has significantly increased risk of postoperative revision.

Abstract:Prosthetic joint infection is one of the serious complications after total joint arthroplasty, which brings serious burden to pa- tients in economy, psychology and life. The pathogenesis is not clear. In recent years, with the development of gene sequencing technology, genetic analysis of complex diseases has become a hot spot. This paper reviews the genetic susceptibility of single nucleotide polymor- phisms of interleukin, mannose-binding lectin, toll like receptor, and tumor necrosis factor in prosthetic joint infection.

Abstract:Meniscus extrusion is an important indicator for evaluating meniscal function and diagnosing meniscal injury. It is an impor- tant factor reflecting the poor prognosis of meniscus repair, and an early signal of knee osteoarthritis, which accelerates the development of osteoarthritis. In recent years, the new technology of meniscus centralization has been extensively studied in biomechanics, animal models, clinical application and efficacy follow-up in the treatment of meniscus extrusion. Therefore, this article will review the related research progress on the etiology, pathogenesis, influence and centralized treatment of the meniscus extrusion.

Abstract:Osteoporotic femoral neck fracture does lead to serious impacts on the elderly patients in physical, psychological and psy- chosocial aspects. Even after successful surgical treatment, it takes a long time to resume the health status to the pre-fracture level, which will be not returned eventually in quite a number of patients. In order to improve the overall health and function of the patients, surgical techniques should be correctly selected. In addition, targeted nursing and rehabilitation, psychological counseling and nutritional support should be strengthened to achieve better health status and recovery of daily life capacity of patients. This paper reviews the literatures on above problems and provides reference for clinical medical staff.

Abstract:Anterior cruciate ligament injury is one of the common sports injuries of the knee joint. There are numerous reasons of ante- rior cruciate ligament injury, which brings great challenges to early clinical diagnosis and treatment. Gait analysis provides objective and ac- curate kinematic and kinetic data to reflect functional changes of limbs in a timely manner. This literature systematically reviews the rele- vant research on gait analysis of anterior cruciate ligament injury, reveals the characteristics of normal gait, the diagnosis and treatment of anterior cruciate ligament injury, in order to provide reference for the gait study of anterior cruciate ligament injury.

Abstract:Perioperative ischemic stroke is one of the serious complications in surgical patients, which is disabling and lethally fatal, and brings heavy economic burden to patients' families. With the continuous development of aging population in China, there are more and more elderly patients with fracture, and the incidence of perioperative stroke also presents an increasing trend, which is worthy of high clini- cal attention. Therefore, it is of positive significance to explore the risk factors related to perioperative ischemic stroke in the fractured elder- ly and to implement effective risk intervention measures to reduce the incidence of stroke and improve the quality of life of patients. This pa- per reviews the clinical risk and intervention of perioperative acute ischemic stroke in the fractured elderly, in order to provide a reference for clinical practice.

Abstract:[Objective] To introduce the surgical technique and preliminary clinical results of arthroscopic reconstruction of coracocla- vicular ligament without coracoid tunnel. [Methods] From April 2020 to September 2021, a total of 18 patients received abovesaid surgical treatment for Rockwood III-V acromioclavicular dislocation. Two clavicular tunnel was established on the lateral clavicle at16% and 25% of its total length respectively, and the coracoid under surface was released arthroscopically. Subsequently, the Tightrope with highstrength sutures and two- end button plates were introduced through a clavicle tunnel, pass under the coracoid bottom, and then pass through the other clavicular tunnel by leading wire. As both end button plates were set on the superior surface of the clavicle, the sutures were pull equally to tighten the Tightrope gradually and reduce the acromioclavicular joint, finally, the sutures were tied and fastened. [Re- sults] All patients had surgical procedures performed successfully without serious complications, and were followed up for 5~22 months. The ASES, VAS and Constant scores significantly improved at the latest follow up compared with those before operation (P＜0.05). [Conclu- sion] Arthroscopic reconstruction of coracoclavicular ligament without coracoid tunnel does achieve satisfactory clinical outcomes for acro- mioclavicular joint dislocation.

Abstract:[Objective] To introduce the surgical technique and preliminary clinical results of modified combined approaches for Klam- mer type Ⅲ posterior Pilon fracture. [Methods] A total of 21 patients received open reduction and internal fixation through posterolateral combined with modified posteromedial approaches for Klammer type III posterior Pilon fracture from January 2018 to April 2021. The pos- terolateral incision was made in the middle line between the posterior edge of the distal fibula and the Achilles tendon, then separate be- tween the peroneus and the flexor hallux longus tendons to expose the posterior column of the distal tibia; while to expose the distal fibula if the full-thickness fasciocutaneous flap was retracted anterolaterally. In addition, the modified posteromedial approach was made along the posteromedial edge of the distal tibia, and separate between the posterior tibialis and the bone with pulling all the tendon, blood vessels and nerve bundles posteriorly to expose the medial column of the distal tibia. [Results] All patients had operation performed successfully, and followed up for (15.2±1.5) months on an average. One patient developed superficial wound infection after operation and healed smoothly af- ter dressing change. At the last follow-up the VAS score for pain was of (1.9±0.2), while the AOFAS ankle hind foot score was of (86.0± 1.4). Radiographically, 18 patients obtained anatomical reduction and 3 patients had articular surface displacement of 1mm to 2mm postop- eratively, all the patients got bony healing of the fracture without loosening or breaking of the implants by the time of the latest follow up. [Conclusion] The posterolateral combined with modified posteromedial approaches for open reduction and internal fixation of Klammer type Ⅲ posterior Pilon fracture in prone position with the advantages of full exposure, high reduction rate and few complications, are safe and effective surgical approaches.

Abstract:[Objective] To introduce the surgical technique and preliminary clinical results of arthroscopy-assisted reduction and per- cutaneous cannulated screw fixation for Sanders type II~III calcaneal fractures. [Methods] From February 2019 to January 2021, 28 pa- tients received abovementioned surgical procedures for Sanders type II~III calcaneal fractures. After pins were inserted into the calcaneal tubercles and the neck of the talus, distraction force was applied by a retractor to restore the length of the calcaneus, and facilitated subtalar arthroscopic procedures by the posterolateral and the lateral portals. The hematoma was removed, while the bone fragments were reduced under direct arthroscopic vision on the posterior articular surface. The calcaneal body fracture was reduced by closed prying to resume Bohler angle, Gissane angle and the height of the calcaneal bone, while the width was restored gradually by continuous pressure applied on the medial and lateral sides with vigorous reduction forceps over plates. Subsequently, percutaneous cannulated screws were placed to fin- ish the internal fixation in proper fracture reduction position. [Results] All the patients were successfully operated on without neurovascular injury and other serious complications, and followed up for (13.3±1.4) months on a mean. At the latest follow-up, the foot and ankle motion and alignment recovered well. According to the AOASF evaluation criteria, the clinical results were excellent in 18 feet, good in 8 feet and fair in 2 feet, with an excellent and good rate of 92.9%. [Conclusion] The arthroscopy-assisted reduction and percutaneous cannulated screw fixation for Sanders type II~III calcaneal fractures do achieve accurate reduction with fewer postoperative complications, and satisfac- tory clinical efficacy.

Abstract:[Objective] To introduce the surgical technique and preliminary results of arthroscopic double-tie-knot suture bridge for fixation of Meryers type IV tibial intercondylar eminence fractures. [Methods] From October 2019 to September 2021, 9 patients received abovementioned surgical procedures for Meyers-McKeever type Ⅳ tibial intercondylar eminence fractures. After arthroscopic debridement and fracture reduction, the lasso suture hook was used to placed two loop sutures around the root of anterior cruciate ligament, and the one end of each suture bundle was crossed over the anterior surface of the ligament to form a suture bridge, then pulled out of the joint. Two bone tunnels 2 mm in diameter were established from the anteromedial and anterolateral margins of the fracture area to the anteromedial surface of the proximal tibia respectively under a ACL guide. Both sides of the suture bundle were introduced into the bone tunnels accord- ingly, pulled out to the anterior medial side of the proximal tibia, finally were tightened and tied for fixation. [Results] All the 9 patients were successfully operated on, with good incisions healing, whereas without complications, such as infection, skin necrosis and neurovascu- lar injury. At the latest follow-up lasted from11 to 26 months, all patients had the stable affected knee with negative Lachman test and ante- rior drawer test, with no claudication or locking, and achieved knee extension-flexion range of motion 0 to 130°, restored to the pre-injury level of daily activity. Compared with those preoperatively, the IKDC score [(43.9±3.6), (90.3±2.9), P＜0.001] and Lysholm score [(32.6± 2.2), (92.7±2.5), P＜0.001] significantly improved at the latest follow-up. In addition, the postoperative images showed good fracture reduc- tion in all patients with fracture healing within 8 to 15 weeks after surgery. [Conclusion] The arthroscopic double-tie-knot suture bridge for fixation of Meryers type IV tibial intercondylar eminence fractures is a simple and effective technique, and achieves satisfactory prelimi- nary clinical consequence.

Abstract:[Objective] To introduce the surgical techniques and preliminary clinical outcomes of autologous platelet- rich plasma (PRP) used for intractable wounds after liposarcoma resection. [Methods] A total of 12 patients with intractable wounds secondary to resec- tion of liposarcoma underwent direct closure of the wound by suture after injection of PRP. The peripheral blood was collected, and 10 ~ 40 ml PRP was prepared. After debridement, the wound was completely filled by PRP once or twice, and closed by suture at the same stage. Ul- trasonography was performed after surgery to confirm the deep space healing, while the growth of wound granulation tissue and wound heal- ing were observed after operation and follow-up. [Results] All the 10 patients had the wound healed at stage Ⅰ, while the other 2 patients had wound healing after secondary debridement, and the second PRP filling and continuous negative pressure drainage with VSD. At the latest follow- up, all patients got good wound healing with good appearance and no sinus formation. [Conclusion] The PRP can fully fill deep space and promote wound healing in the treatment of refractory wound secondary to liposarcoma resection, and does achieve satisfacto- ry clinical efficacy.

Abstract:[Objective] To introduce the surgical technique and preliminary clinical results of reduction and internal fixation with plate and intermedullary nail using a distractor in lateral position with knee flexion for tibiofibular fractures. [Methods] From June 2020 to June 2021, 46 patients received the abovesaid surgical treatment for tibiofibular fractures. The patient was placed in the lateral decubitus posi- tion with knee flexion in 90 degrees and the affected limb parallel to the healthy limb. Schanze pins were inserted in the tibial plateau and calcaneus respectively, and then the shelf-developed retractor was attached with the pins applying axial distraction force to reduce the frac- tures and maintain the reduction. Under this condition, the fibular fractures were fixed with a plate by MIPPO technique through small inci- sions, subsequently, the tibial fractures were fastened with an interlocking intermedullary nail inserted through the inferior patellar ap- proach. [Results] All the patients had operations conducted successfully, without neurovascular injury or other serious complications, while with operation time of (118.5±2.0) min, intraoperative blood loss of (120.8±8.1) ml, and X-ray exposure time of (20.1±3.2) s. The patients were followed up for (12.3±2.2) months on a mean, and got clinical healing of the fractures in (24.1±1.8) weeks postoperatively, and were marked American Society for Foot and Ankle Surgery's ankle-hindfoot score of (92.8±2.6) at the latest follow-up. [Conclusion] The reduc- tion and internal fixation with plate and intermedullary nail using self-developed distractor in lateral kneeling position for tibiofibular frac- tures do facilitate surgical operation, intraoperative fluoroscopy to achieve rapid facture reduction, with advantages of reducing the loss of in- traoperative reduction and shortening the operation time.

Abstract:[Objective] To investigate the clinical outcomes of percutaneous vertebroplasty (PVP) for thoracolumbar burst fractures without nerve deficit in the elderly. [Methods] Forty-eight elderly patients received PVP for thoracolumbar burst fractures without nerve deficit from September 2017 to September 2020. The clinical and radiographic documents were analyzed. [Results] All the 48 patients had operation conducted smoothly without serious complications. Of them, 8 patients proved bone cement leakage, accounting for 16.7%, where- as which not led to severe consequences, such as cement embolism and nerve injuries. As time went in the follow-up period lasted from 9 to 36 months with an average of (23.3±3.6) months, the VAS and ODI scores significantly decreased (P＜0.05). Radiographically, the relative anterior vertebral height significantly increased, whereas the local kyphotic Cobb angle significantly declined postoperatively compared with those preoperatively (P＜0.05). Until the latest follow up, no new-occurred fracture or adjacent segment fracture was found in anyone of them. [Conclusion] PVP is still a reliable treatment for thoracolumbar burst fractures without nerve injury in the elderly.

Abstract:[Objective] To investigate the clinical outcomes of calcaneoplasty and reattachment of Achilles tendon in the treatment of Haglund syndrome. [Methods] A retrospective study was performed on 26 patients who underwent calcaneoplasty and reattachment of Achilles tendon for Haglund syndrome in our hospital from January 2017 to January 2019. The clinical and radiological documents were evaluated. [Results] All the patients had the surgical procedures performed successfully without any complications such as vascular and nerve injury, whereas with operation time of (58.3±17.9) min, intraoperative blood loss of (50.8±22.6) ml, and hospital stay of (6.8±1.1) days. All of them were followed up for (22.3±9.5) months on an average. With time elapsed preoperatively, 6 and 12 months postoperatively and the latest follow-up, the VAS score significantly reduced [(5.3±2.0), (2.5±1.2), (1.2±0.9), (1.2±0.8), P＜0.05], whereas the AOFAS score [(62.6±8.4), (80.6±7.6), (87.9±6.7), (89.7±5.1), P＜0.05] and ankle dorsal extension- plantar flexion range of motion (ROM) [(33.5±9.0)°, (54.0±9.2)°, (61.3±7.7)°, (64.8±9.4)°, P＜0.05] significantly increased. Radiographically, compared with those preoperatively, the parallel pitch lines (PPL) positive ratio (61.5% vs 0%, P＜0.05) and posterior calcaneal angle (Fowler-Philip angle, FPA) [(61.8±5.8) ° vs (41.3± 5.6)°, P＜0.05] significantly decreased postoperatively. [Conclusion] The open calcaneoplasty and reattachment of Achilles tendon have clear exposure to remove the complicated pathology involving various tissues, and achieve satisfactory clinical outcomes.

Abstract:[Objective] To evaluate the clinical results of robot-assisted pedicle screw fixation of thoracolumbar fracture of ankylosing spondylitis(AS). [Methods] A retrospective study was conducted on 15 patients who received surgical treatment for thoracolumbar fracture complicated with ankylosing spondylitis from January 2016 to June 2021. According to the doctor-patient communication, 8 patients re- ceived robot-assisted screw placement, while the remaining 7 patients were treated with freehand secrew placement. The perioperative con- ditions and follow-up results were compared between the two groups. [Results] All the patients in both groups had operation completed suc- cessfully. The robot group proved significantly superior to the freehand group in term of accuracy of screw placement, whereas the former had significantly less intraoperative fluoroscopy and fluoroscopy dose, and significant greater hospitalization cost than the latter (P＜0.05). There was no significant difference between two groups in the time to resume full weight- bearing activity (P＞0.05). The VAS and ODI scores significantly decreased (P＜0.05), while JOA scores significantly increased in both groups over time (P＜0.05), which were not statisti- cally significant between the two groups at any corresponding time points (P＞0.05). [Conclusion] Robot-assisted pedicle screw fixation of AS thoracolumbar fractures does improve the accuracy of screw insertion, reduce radiation injury, and improve the safety of surgery.

Abstract:[Objective] To compare the early clinical outcomes of 3D printing assisted pedicle screw placement versus conventional free- hand technique for the upper cervical deformity. [Methods] From May 2010 to May 2019, 18 patients received atlantoaxial or occipitocervi- cal instrumented fusion for upper cervical deformity in our hospital. Of them, 10 patients had screws placed with 3D printed guider individu- ally, while the other 8 patients were by conventional hands-free technique. The early clinical and imaging data were compared between the two groups. [Results] All patients were successfully operated on with a total of 72 screws inserted, including 40 screws in the 3D group and 32 screws in the freehand group. The 3D group proved significantly superior to the freehand group in terms of operative time [(189.7±16.1) min vs (242.1±23.2) min, P＜0.001], intraoperative blood loss [(216.6±49.8) ml vs (385.0±23.5) ml, P＜0.001], placement time per screw [(3.3± 0.8) min vs (7.0±1.1) min, P＜0.001] and the number of X- ray exposure [(8.7±1.1) times vs (30.0±3.3) time, P＜0.001]. Radiographically, there were no significant differences between preoperative simulation and real operation in the 3D group regarding screw diameter, length and distance from the posterior median line (P＞0.05). The accuracy rate of screw placement in 3D group was significantly higher than that in freehand group (97.5% vs 81.3%, P＜0.05). [Conclusion] Compared with traditional handsfree screw placement, the 3D printing assisted pedicle screw placement has higher accuracy and improved surgical efficiency.

Abstract:[Objective] To investigate the clinical efficacy of the posteromedial and anterolateral approaches for open reduction and in- ternal fixation (ORIF) of complex tibial plateau fractures involving the posteromedial plateau. [Methods] A total of 33 patients received OR- IF for complex tibial plateau fractures involving the posteromedial plateau through the posteromedial and anterolateral approaches in our de- partment from April 2017 to March 2021. The clinical and imaging results were observed. [Results] All patients were operated on success- fully without serious complications such as neurovascular injury, and were followed up for (23.5±8.3) months on an average, resumed full weight bearing in (17.6±2.1) weeks. Compared with those 3 months after surgery, the knee extension-flexion range of motion (ROM) and knee HSS scores significantly increased at 12 months after surgery and at the last follow-up (P＜0.05), whereas the Rasmussen score re- mained unchanged (P＞0.05). Radiographically, the MPTA and PTS had no significant changes at 12 months and the last follow-up com- pared with those 3 months after surgery (P＞0.05), while the tibial plateau fractures healed in all patients at 10~16 weeks postoperatively. At the last follow-up, 2 patients had moderate stenosis of joint space, 8 patients had obvious osteophyte formation of the knee joint, and the de- generation was significantly deteriorated at 12 months compared with that 3 months postoperatively (P＜0.05). However, no revision surgical operation was performed in anyone of them until the latest follow-up. [Conclusion] The posteromedial and anterolateral approaches for OR- IF of complex tibial plateau fractures involving the posteromedial plateau do achieve accurate reduction and firm internal fixation, which is conducive to early functional exercise of the knee joint, with few complications while satisfactory clinical efficacy.