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Objective: Unstable fractures of the sacrum often occur in patients with pelvic fractures and represent a real challenge for the orthopedic surgeon. Triangular osteosynthesis (TOS) and lumbopelvic fixation (LP) may represent a valid management option for the treatment of this condition. We present a systematic literature review about lumbopelvic fixation and triangular fixation as treatment option for unstable sacral fractures, to assess clinical and radiological outcomes after surgery and to evaluate appropriate indications and impact on the natural history of sacral fractures. Methods: The review is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. 50 articles out of 108 titles, were considered eligible for the full-text analysis. Finally, 16 studies that met inclusion criteria were included in this review. Results: Overall, 212 patients (87 males, 58 females) with sacral fractures treated with TOS triangular fixation or LP lumbopelvic fixation were collected. The mean age was 37.6 years. Mean follow-up reported in all studies was 24.14 months. Conclusion: The results presented by the different authors, highlight the effectiveness of TOS triangular fixation and LP lumbopelvic fixation for the treatment of unstable sacral fractures associated with other pelvic fractures, in terms of function, stability, cost-effectiveness, and quality of life postoperatively.

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Objective: To determine the efficacy of femoral neck system compared to dynamic hip screws in treating femoral neck fractures. METHODS: The systematic review was conducted from January to March 2023, and comprised literature search on PubMed, Embase, Scopus, Ovid, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure and Wanfang databases for relevant studies published up to March 1, 2023. Study data as well as demographic and outcome parameters related to the patients were extracted, and the methodological index for non-randomised studies was used to assess the risk of bias. Review Manager software was used to conduct metaanalysis. RESULTS: Of the 567 studies initially found, 6(1%) were included, with the publication date ranging from August 2021 to February 2023. There were 5(83.3%) studies published in English and 1(16.7%) in Chinese. Of the 577 patients with femoral neck fractures, 287(49.7%) were treated with femoral neck system and 290(50.3%) with dynamic hip screws. Significant differences were shown between the two groups regarding operation duration, blood loss, internal fixation failure rate and Harris hip score (p=<0.05). There was no significant differences between the groups regarding time from injury to surgery, hospitalisation, complication rate and femoral neck shortening rate (p>0.05). Conclusion: The novel femoral neck system could optimise surgical procedures, with shorter operation times and lesser blood loss. The femoral neck system and dynamic hip screws were comparable in terms of complication rates and postoperative hip function.

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Middle-aged and elderly patients with femoral neck fracture often suffer from basic diseases. Conservative treatment will significantly increase the incidence of complications. At present, surgical treatment is mostly advocated. Internal fixation is one of the effective treatment methods for middle-aged and elderly patients with femoral neck fracture. It has the advantages of improving hip joint function, accelerating patient recovery, and improving patient quality of life. At present, there are many choices of internal fixation in the world, each has its own advantages and disadvantages, and there is no unified standard. Different surgical methods can be selected according to various factors such as fracture type, patient′s physical condition and surgical auxiliary technology. This article reviews the clinical progress of internal fixation for femoral neck fractures in middle-aged and elderly patients from four aspects: the characteristics of femoral neck fractures in middle-aged and elderly patients, common internal fixation methods, 3D printing guide plate auxiliary technology and artificial intelligence auxiliary technology.

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Objective:To explore the clinical outcome of internal fixation in the treatment of AO C-type distal radius fracture accompanied with dorsoulnar fragment involving 1/8 to 1/3 of the articular surface of the lunate facet.Methods:A total of 55 patients of AO C-type distal radius fracture accompanied with dorsoulnar fragment involving 1/8 to 1/3 of the articular surface of the lunate facet from July 2017 to July 2022 in Tongji Hospital Affiliated to Tongji University were retrospectively analyzed. In the volar plate group (volar locking plate treatment alone), there were 22 cases, 11 males and 11 females, aged 56.7±10.1 years, 10 C1 type, 7 C2 type and 5 C3 type. There were 15 patients in the volar plate+dorsal plate group (treated with volar locking plate combined with dorsal plate), including 6 males and 9 females, aged 55.7±8.1 years old, 4 C1 type, 5 C2 type and 6 C3 type. In the volar plate+dorsal screw group (treated with volar locking plate combined with dorsal screw), there were 18 cases, 8 males and 10 females, aged 53.5±11.6 years, 7 cases of C1 type, 5 cases of C2 type, and 6 cases of C3 type. The operation time, postoperative radiographic indicators, wrist range of motion (ROM), disability of arm, shoulder and hand (DASH) score, visual analogue scale (VAS) and postoperative complications were evaluated and compared between the three groups.Results:All operations were successfully completed. Patients were followed up for 14.9 ± 2.2 months (range, 12-18 months), and the fracture healing time was 12.4±2.3 weeks (range, 9-16 weeks). The operative time of patients in the volar plate group, volar plate+dorsal plate group and volar plate+dorsal screw group was 54.3±7.6 min, 70.7±5.9 min and 65.8± 7.1 min, respectively. Patients in the volar plate group had less operative time ( F=27.04, P<0.001). The residual displacement of the dorsoulnar fragment in sagittal, coronal, and axial CT scans in the three groups were (1.3±0.8 mm, 0.6±0.4 mm, 0.7±0.4 mm), (1.1±0.8 mm, 0.6±0.4 mm, 0.6±0.6 mm), (1.4±0.8 mm, 0.7±0.4 mm, 0.7±0.5 mm). The displacement of the dorsoulnar fragment of the two groups of combined volar and dorsal internal fixation was smaller than that of the volar plate group ( P<0.05). The ROM of wrist flexion of the three groups at 3 months after operation were 44.2°±4.6°, 47.7°±5.9°, 48.8°±5.1°, the ROM of wrist extension were 39.8°±6.2°, 44.3°± 4.6°, 44.7°±5.1°, the wrist DASH scores were 23.0±4.2, 20.1±4.1 and 19.4±3.0, and the VAS were 2.3±1.2, 1.6±1.3 and 1.3±1.0, respectively. The ROM of wrist flexion and extension and DASH score in volar plate+dorsal plate group were better than those in volar plate group ( P<0.05). The ROM of wrist flexion and extension, DASH score and VAS in the volar plate+dorsal screw group were better than those in the volar plate group ( P<0.05). There were no significant differences in terms of the wrist ROM, DASH score and VAS at 12 months after operation among the three groups ( P>0.05). There were 2 patients in the volar plate group with reduction loss, 3 patients with wrist chronic pain; 1 patient in the volar plate combined with dorsal plate group with dorsal tendon irritation, and no complications in the volar plate combined with dorsal screw group. Conclusion:For AO C-type distal radius fractures accompanied with a dorsoulnar fragment involving 1/8 to 1/3 of the articular surface of the lunate facet, the use of combined volar and dorsal internal fixation can improve the reduction accuracy and stability of the dorsoulnar fragment, and contribute to the early rehabilitation of postoperative wrist joint function. The effect of combined dorsal screw is comparable to that of dorsal plate internal fixation, but the complications of screw internal fixation are less.

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With the increasing prevalence of total knee arthroplasty (TKA), there is a corresponding rise in the number of patients requiring revision of total knee arthroplasty (R-TKA) for various reasons. R-TKA presents several complex challenges, with severe bone defect reconstruction being a critical obstacle to securing favorable long-term outcomes. Recently, the approach to managing bone defects has seen significant advancements, with a range of techniques proposed contingent on the defect's size and location. Severe bone defects require reconstruction with autologous or allogeneic bone grafts or metal fillers. However, bone grafts have their usage constrained by limited availability, risks of resorption and collapse, and the potential for disease transmission. Consequently, metal fillers have received widespread attention in practical applications due to their advantages, such as comprehensive source, customizability, and safety. The advantages of metal augment are that they provide immediate support without reinforcement and are not subject to necrosis and resorptive collapse. However, the difference in elastic modulus between metal and bone may lead to stress shielding and increase the risk of potential bone loss. Both Cone and Sleeve can achieve biological fixation of metaphyseal bone; however, in cases of periprosthetic infections, it is generally difficult to remove them easily due to the prosthetic bone in-growth and osseointegration. This study aims to provide a comprehensive review of the use of metal fillers to reconstruct bone defects during R-TKA. It is intended to aid orthopedic surgeons in understanding the spectrum of reconstructive possibilities and provide high-performance revision strategies for their patients.

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Objective:To explore the clinical effect of plating after lengthening to assist the consolidation of tibial shortening deformity in children.Methods:A retrospective analysis was conducted on 10 children with tibial shortening who were treated with circular external fixator lengthening and replacement with plate-assisted internal fixation (study group) in the Department of Pediatric Orthopedics of Tianjin Hospital from November 2019 to October 2022, and 16 children who were treated by circular external fixator only during the same period were enrolled as the external fixator group (control group). Among the 26 cases, there were 15 males and 11 females, 10 left knees and 16 right knees. The average age at the time of surgery was 8.8±4.7 years (range 5.1-13.8 years). The gender, side, age at the time of surgery were compared between the two groups. The extension length, external fixator index, healing index, Kolcaba comfort scale score, knee and ankle joint range of motion, complications and average total hospitalization costs were recorded.Results:There were no significant differences in gender, side, age at the time of surgery between the study group and control group. The extended lengths were 5.44±1.25 cm and 5.78±1.11 cm respectively without significant difference ( t=0.096, P=0.096). The external fixator index and healing index were 17.86±2.94 d/cm vs. 50.97±7.03 d/cm and 40.94±6.63 d/cm vs. 45.24±5.98 d/cm in study group and the control group with significant differences ( t=13.299, P<0.001; t=1.289, P=0.033). The Kolcaba comfort scale score of the children in the study group was higher than that of the control group, with significant difference ( t=6.821, P=0.001). Comparing the range of motion of the knee and ankle joints between the two groups, there were no significant differences before surgery, at the end of extension surgery, and at the final follow-up. When the extension end was healed, the range of motion of the knee joint was137.89°±4.40° vs. 114.09°±13.60° and ankle joint was 64.35°±5.50° vs. 56.65°±8.86° in the study group and control group with significant difference ( t=17.235, P<0.001; t=7.821, P=0.002). In the study group, 4 cases had pin tract infection, but no refracture occurred; in the control group, pin tract infection occurred in 13 cases, and refracture occurred in 2 cases after removal of the external fixator. The average total hospitalization cost of the study group was higher than that of the control group with significant difference ( t=3.745, P=0.036). Conclusion:The clinical effect of replacing plate-assisted internal fixator during the mineralization period of tibial shortening in children is reliable, and can significantly shorten the time for using external fixator. It is beneficial to the healing of the extended end of the osteotomy and the functional recovery of the knee and ankle joints. Being more comfortable for children with fewer complications, it is applicable for children who need long-distance extension, multiple extensions with limited joint function, poor tolerance for external fixators and low treatment compliance.

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Objective:To investigate the clinical efficacy of two different internal fixations in the treatment of femoral intertrochanteric fractures in older adult patients.Methods:The clinical data of 152 older adult patients with femoral intertrochanteric fractures who were treated at the Second People's Hospital of Hefei from January 2019 to December 2022 were retrospectively analyzed. All patients underwent closed reduction and internal fixation surgery. They were divided into two groups based on the different types of internal fixations used. Among them, 76 patients received internal fixation using proximal femoral intramedullary nails (group A), while 76 patients received internal fixation using Intertan nails (group B). The intraoperative blood loss volume, surgical time, postoperative complications, fracture healing time, and hip joint function score were compared between the two groups.Results:The intraoperative blood loss volume in group A was (197.11 ± 37.85) mL, which was significantly less than that in group B [(226.84 ± 54.17) mL, t = 1.62, P < 0.001]. Surgical time in group A was (71.16 ± 15.64) minutes, which was significantly shorter than that in group B [(78.49 ± 15.88) minutes, t = 1.67, P < 0.001]. The fracture healing time in group A was (13.29 ± 0.94) weeks, which was not significantly different from that in group B [(13.20 ± 0.64) weeks, t = 0.33, P > 0.05]. However, the incidence of postoperative complications in group A was 5.26% (4/76), which was significantly higher than 1.32% (1/76) in group B ( χ2 = 4.04, P = 0.048). At 1 and 3 months and 1 year after surgery, the hip joint function score in group A was (63.13 ± 2.41) points, (73.50 ± 3.99) points, and (84.13 ± 7.57) points, respectively, and it was (68.65 ± 2.65) points, (79.07 ± 3.38) points, and (89.56 ± 7.71) points, respectively, in group B. At the above-mentioned time points, the difference in hip joint function score between the two groups was statistically significant ( t = 1.89, 2.48, 2.49, all P < 0.001). Conclusion:Both internal fixation methods have significant therapeutic effects on femoral intertrochanteric fractures. Internal fixation using Intertan nails leads to higher hip joint function scores and fewer postoperative complications compared with internal fixation using proximal femoral intramedullary nails, but it results in more blood loss and a longer surgical time.

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Objective:To compare the biomechanical properties of the modified and traditional iliolumbar pedicle screw-rod system for the fixation of vertically unstable posterior pelvic ring dislocation.Methods:The CT images of the lumbar spine, pelvis, and femur from a 31-year-old healthy male volunteer were used to establish models of posterior pelvic ring dislocation and unilateral and bilateral fixation models of modified and traditional iliolumbar pedicle screw-rod systems with the three-dimensional virtual software using the finite element method. By restraining the distal ends of the femurs of both sides and applying a vertical load of 500 N to the L 1 vertebral body, the maximum stress of the intact pelvis model and the stiffness of the posterior pelvic ring dislocation model were evaluated to validate the reliability of the models. After the validation of the models, a follower load of 400 N was applied in the direction of the L 1 vertebral curve to simulate the upper body weight; the maximum vertical displacement, the maximum posterior displacement, the maximum right displacement, and the overall maximum displacement of the sacrum of the modified and traditional iliolumbar pedicle screw-rod system models were compared. Additionally, stress distributions of the implant and the pelvis were also compared. Results:(1) The maximum stress of the intact pelvis model was 22.0 MPa, with the stiffness of the posterior pelvic ring dislocation model as 180.03 N/mm. (2) In terms of the maximum vertical displacement of the sacrum, the bilateral modified iliolumbar pedicle screw-rod system was similar to the bilateral traditional iliolumbar pedicle screw-rod system. However, the maximum posterior displacement, the maximum right displacement, and the overall maximum displacement of the sacrum in the bilateral modified iliolumbar pedicle screw-rod system were 0.57 mm, 0.19 mm and 0.68 mm respectively, which were markedly smaller than those of the bilateral traditional iliolumbar pedicle screw-rod system (1.38 mm, 0.26 mm and 1.41 mm respectively). (3) The maximum vertical displacement, the maximum posterior displacement, the maximum right displacement, and the overall maximum displacement of the sacrum in the unilateral modified iliolumbar pedicle screw-rod system were 0.70 mm, 0.73 mm, 0.17 mm and 0.88 mm respectively, which were markedly smaller than those of the unilateral traditional iliolumbar pedicle screw-rod system (1.17 mm, 2.21 mm, 0.31 mm and 2.29 mm respectively). (4) The stress of the implant was concentrated on the connecting rod between the iliac pedicle screw-rod and the lumbar pedicle screw-rod in the modified iliolumbar pedicle screw-rod system, but it was mainly concentrated on the connecting rod at the upper edge of the iliac screw in the traditional iliolumbar pedicle screw-rod system. The maximum stress of the implant was 340.84 MPa in the bilateral modified iliolumbar pedicle screw-rod system, which was 30.4% less than that in the bilateral traditional iliolumbar pedicle screw-rod system (489.77 MPa), and was 351.23 MPa in the unilateral modified iliolumbar pedicle screw-rod system, which was 15.5% less than that in the unilateral traditional iliolumbar pedicle screw-rod system (415.82 MPa). (5) In both modified and traditional iliolumbar pedicle screw-rod systems, the stress of the pelvis was concentrated on the contact area between the iliac screw and the cortical bone. The maximum stress of the pelvis was 19.21 MPa in the bilateral modified iliolumbar pedicle screw-rod system, which was 78.1% less than that in the bilateral traditional iliolumbar pedicle screw-rod system (87.59 MPa), and was 39.91 MPa in the unilateral modified iliolumbar pedicle screw-rod system, which was 70.4% less than that in the unilateral traditional iliolumbar pedicle screw-rod system (134.98 MPa).Conclusion:Compared with the traditional iliolumbar pedicle screw-rod system, the modified iliolumbar pedicle screw-rod system can effectively reduce the displacements of all directions in vertically unstable posterior pelvic ring dislocation and significantly reduce the stress of the implant and the pelvis, thus having good biomechanical stability.

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Acromioclavicular joint dislocation is a common shoulder injury caused by injuries to the acromioclavicular and coracoclavicular ligaments, which may result in pain and limited mobility in the affected shoulder. Currently, hook plate fixation is commonly used to treat Rockwood type III-VI acromioclavicular joint dislocation in clinical settings. However, there are complications such as subacromial impingement and osteolysis. Therefore, the treatment has gradually shifted from rigid fixation to elastic fixation, with a preference for reconstruction of the coracoclavicular ligament. The internal fixation with the Endobutton system allows for micro-movement of the acromioclavicular joint, but its loop length can′t be freely adjusted. The Tightrope system is developed based on the improvement of the Endobutton system, which has been increasingly used in clinical settings in recent years, with the advantages of easy operation, adjustability and minimal trauma. However, postoperative complications such as clavicular and/or coracoid fractures and loss of reduction are prone to occur. To date, there are various and inconsistent treatment plans of internal fixation with Tightrope system for acromioclavicular joint dislocation, and their clinical effects vary. To this end, the authors reviewed the structure, biomechanics, surgical techniques, and therapeutic effects of the internal fixation with Tightrope system in the treatment of acromioclavicular joint dislocation, aiming to provide a reference for the selection of its clinical treatment.

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Objective:To compare the efficacy of pedicle screw placement between computer navigation guidance and freehand assistance in the surgical treatment of isthmic spondylolysis at the lumbar vertebrae.Methods:A retrospective study was conducted to analyze the 47 patients with bilateral isthmic spondylolysis at the L 5 vertebra who had been treated at Department of Spinal Surgery, The General Hospital of Xinjiang Military Command from January 2020 to April 2023. All were male patients with an age of (24.0±4.3) years. They were divided into a study group (13 cases subjected to pedicle screw placement assisted by computer navigation guidance) and a control group (34 cases subjected to pedicle screw placement assisted freehandedly). The 2 groups were compared in terms of surgical incision length, intraoperative bleeding, screw placement time, postoperative hospital stay, total hospitalization cost, postoperative complications, rate of screw reposition, angle between pedicle screw and upper endplate, angle between bilateral pedicle screws, and placement accuracy; the visual analogue scale (VAS) for pain, Japanese Orthopaedic Association (JOA) score for lumbar spine function, and Oswestry disability index (ODI) were also compared between preoperation, 1-week postoperation, and the last follow-up. Patient satisfaction was assessed according to the modified MacNab criteria, and internal fixation failure and isthmic healing were also evaluated at the last follow-up. Results:There were no statistically significant differences in the preoperative general data between the 2 groups, showing comparability ( P>0.05). The differences were not statistically significant in surgical incision length, intraoperative bleeding, screw placement time, postoperative hospital stay, or postoperative complications ( P>0.05). However, in the study group, the total hospitalization cost was significantly higher than that in the control group, the rate of screw reposition [7.7% (2/26)] significantly lower than that in the study group [26.5% (18/68)], the angle between pedicle screw and upper endplate and the angle between bilateral pedicle screws were both significantly smaller than those in the control group, and the placement accuracy [92.3% (24/26)] was significantly greater than that [70.6% (48/68)] in the control group (all P<0.05). All patients were followed up for 7.0 (5.0, 14.0) months. Patients in both groups showed significant improvements in VAS, JOA score, and ODI at postoperative 1 week and the last follow-up compared with the preoperative values, and the improvements at the last follow-up were significantly larger than those at postoperative 1 week ( P<0.05). According to the modified MacNab criteria at the last follow-up, patient satisfaction was rated as excellent in 10 cases, as good in 2 cases and as moderate in 1 case in the study group while as excellent in 27 cases, as good in 3 cases, as moderate in 3 cases and as poor in 1 case in the control group. In the study group, there were 1 case of internal fixation failure, 1 case of spine cutting-out by titanium cable, and 12 cases of bony healing of the isthmus; in the control group, there were 2 cases of internal fixation failure, 2 cases of spine cutting-out by titanium cable, and 29 cases of bony healing of the isthmus. Conclusions:In the surgical treatment of bilateral isthmic spondylolysis at the L 5 vertebra, computer navigation-guided pedicle screw placement is safe and reliable, showing an advantage of higher accuracy over freehand placement. It deserves clinical promotion due to its satisfactory therapeutic effects.

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BACKGROUND: Ilizarov method has become one of primary methods for treating bone defects. Currently, there is growing trend in the application of modified Ilizarov methods (e.g., applying unilateral external fixators or with flap tissue) and its combined methods (e.g., Ilizarov method with antibiotic spacer or internal fixation) to manage bone defects. However, there is a lack of studies with systematical evaluation of the clinical effects of these evolving methods. This study aimed to conduct a systematic review and meta-analysis for overall evaluating the clinical effects on long bone defects of lower extremity in Ilizarov methods and its combined methods. METHODS: Studies were identified in three electronic databases (Pubmed, Embase and Cochrane Library) from the earliest indexing year through November 01, 2022, and relevant data were extracted subsequently. The total number of participants, number of participants with bone unions, bone result or functional result, and related complications including pin infection, pin loosening, pain, refracture, limb discrepancy, malalignment, joint stiffness, recurrent infection, and amputation were extracted in this study. Then, union rate (defined as the proportion of patients who achieved bone unions) and specific complication incidence rate (defined as the proportion of patients who experienced specific complication) were pooled estimated respectively. Relative risk (RR) was used for comparing the clinical effects among various Ilizarov technique. RESULTS: Sixty-eight case series studies, 29 comparative studies, and 3 randomized clinical trials were finally included. The union rate of Ilizarov methods was 99.29% (95% CI: 98.67% ~ 99.86%) in tibial defects and 98.81% (95% CI: 98.81% ~ 100.00%) in femoral defects. The union rate of Ilizarov method with antibiotic spacer and intramedullary nail in tibial defects was 99.58% (95% CI: 98.05% ~ 100.00%) and 95.02% (95% CI: 87.28% ~ 100.00%), respectively. Compared to the Ilizarov methods, the union rate of the Ilizarov method with antibiotic spacer in tibial defects increased slightly (RR = 1.02, 95% CI: 1.01 ~ 1.04). Meanwhile, compared to Ilizarov methods, we found lower excellent rate in bone result in Ilizarov method with antibiotic spacer, with the moderate to high heterogeneity. Compared to the Ilizarov method, lower rate of pin infection, higher rate of recurrent infection and amputation were observed in Ilizarov method with intramedullary nail, however, the findings about the comparison of pin infection and recurrent infection between the two groups were presented with high degree of statistical heterogeneity. CONCLUSION: Our study confirmed the reliable treatment of Ilizarov methods and its combined technique on long bone defects, and founded there were significant differences on some complications rate between Ilizarov methods and its combined technique. However, the findings need to be confirmed by further studies.

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The treatment of complex acetabular fractures remains a complicated clinical challenge. Our self-designed novel anatomical locking guide plate (NALGP) has previously shown promising potential in T-shaped acetabular fractures (TAF), but a direct comparison with conventional fixations is yet to be made. The TAF model was established based on a volunteer's computer tomography data and then fixed with double column locking plates (DLP), a posterior column locking plate with anterior column screws (LPACS), and our NALGP. Forces of 200 N, 400 N, and 600 N were then loaded on the model vertically downward, respectively. The stress distribution and peaks and maximum displacements at three sites were assessed. We found that the stress area of all three plates was mainly concentrated around the fracture line, while only the matching screws of the NALGP showed no obvious stress concentration points. In addition, the NALGP and DLP showed significantly less fracture fragment displacement than the LPACS at the three main fracture sites. The NALGP was found to have less displacement than DLP at the posterior column and ischiopubic branch sites, especially under the higher loading forces of 400 N and 600 N. The fixation stability of the NALGP for TAF was similar to that of DLP but better than that of LPACS. Moreover, the NALGP and its matching screws have a more reasonable stress distribution under different loads of force and the same strength as the LPACS.

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OBJECTIVE: To evaluate the biomechanical stability of anterior transarticular crossing screw (ATCS) and compare it with anterior transarticular screw (ATS) which may provide basic evidence for clinical application. METHODS: Eight human fresh cadaveric specimens (occiput-C4) were tested with 5 conditions including the intact status, the injury status (type II odontoid fracture), the injury+ATS fixation status (traditional bilateral ATS fixation); the injury+unilateral ATCS fixation status; and the injury+bilateral ATCS fixation status. Specimens were applied to a pure moment of 1.5 Nm in flexion-extension, lateral bending, and axial rotation, respectively. The range of motions (ROMs) and the neutral zones (NZs) of C1 to C2 segment were calculated and compared between 5 status. RESULTS: ATS and ATCS fixations significantly reduced the motions in all directions when compared with the intact and injury statues (p < 0.05). In flexion-extension, the ROMs of ATS, unilateral ATCS, and bilateral ATCS were 4.7° ± 2.5°, 4.1° ± 1.9°, and 3.2° ± 1.2°, respectively. Bilateral ATCS resulted in a significant decrease in ROM in flexion-extension when compared with ATS and unilateral ATCS (p = 0.035 and p = 0.023). In lateral bending and axial rotation, there was no significant difference in ROM between the 3 fixations (p > 0.05). Three fixations resulted in similar NZs in all directions (p > 0.05). CONCLUSION: ATCS is a biomechanically effective alternative or supplemental method for atlantoaxial instability.

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Background: Kirschner wire (K-wire) fixation is widely used to repair metacarpal and phalangeal fractures. In this study, we simulated K-wire osteosynthesis of a 3-dimensional (3D) phalangeal fracture model and investigated the fixation strength at various K-wire diameters and insertion angles to clarify the optimal K-wire fixation method for phalangeal fractures. Methods: The 3D phalangeal fracture models were created by using computed tomographic (CT) images of the proximal phalanx of the middle finger in five young healthy volunteers and five elderly osteoporotic patients. Two elongated cylinders representing K-wires were inserted according to various cross-pinning methods; the wire diameters were 1.0, 1.2, 1.5 and 1.8 mm, and the wire insertion angles (i.e. the angle between the fracture line and the K-wire) were 30°, 45° and 60°. The mechanical strength of the K-wire fixed fracture model was investigated by using finite element analysis (FEA). Results: The fixation strength increased with increasing wire diameter and insertion angle. Insertion of 1.8-mm wires at 60° achieved the strongest fixation force in this series. Fixation strength was generally stronger in the younger group than the elderly group. Dispersion of stress to cortical bone was a critical factor to increase fixation strength. Conclusions: We developed a 3D phalangeal fracture model into which we inserted K-wires; using FEA, we clarified the optimal crossed K-wire fixation method for phalangeal fractures. Level of Evidence: Level V (Therapeutic).

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OBJECTIVE: Screw loosening is a widely reported issue after spinal screw fixation and triggers several complications after lumbar interbody fusion. Osteoporosis is an essential risk factor for screw loosening. Hounsfield units (HU) value is a credible indicator during bone mineral density (BMD) evaluation. As compared with the general evaluation of BMD, we hypothesized that specific measurements of HU at the precise location of the future screw insertion may be a better predictor of screw loosening. METHODS: Clinical data of 56 patients treated by oblique lumbar interbody fusion (OLIF) of the L4-L5 segments with an anterior lateral single rod (ALSR) screw fixation were reviewed in this study. Vertebral bodies with ≥ 1 mm width radiolucent zones around the screw were defined as screw loosening. HU in the insertional screw positions, the central transverse plane, and the average values of three and four planes were measured. Regression analyses identified independent risk factors for screw loosening separately. The area under the receiver operating characteristic curve (AUC) was computed to evaluate predictive performance. RESULTS: The local HU values were significantly lower in the loosening group, regardless of the selected measuring methods. The AUC of screw loosening prediction was higher in the insertional screw positions' HU than other frequently used methods. CONCLUSIONS: The HU value measured in the insertional screw position is a better predictor of ALSR screw loosening than other methods. The risk of screw loosening should be reduced by optimizing the trajectory of the screw based on the measurement of HU in preoperative CT. KEY POINTS: • Osteoporosis is an essential risk factor for screw loosening, and Hounsfield units (HU) are a credible predictor during bone mineral density (BMD) evaluation. • The HU value measured in the insertional screw position is a better predictor of screw loosening than other frequently used HU measurement methods. • The risk of screw loosening might potentially be reduced by optimizing the trajectory of the screw based on the measurement of HU in preoperative CT.

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Objective:To analyze the efficacy of vertebroplasty combined with posterior decompression and internal fixation in the treatment of spinal metastases with neurological symptoms.Methods:This study was a retrospective analysis of 32 cases with neurological symptoms caused by spinal metastatic tumor in the Department of Orthopedics, Beijing Friendship Hospital, Capital Medical University from June 2016 to January 2022. All 32 patients (20 males, 12 females) aged between 39 to 85 years were enrolled in this study, with a mean age of (64.8±11.9) years. Surgery time, bleeding volume, modified Tokuhashi score, spinal instability neoplastic score (SINS) were collected. The visual analogue score (VAS), Oswestry disability index (ODI), Karnofsky performance scale (KPS) and American spinal cord injury association (ASIA) score before surgery, 1 month after surgery, 3 months after surgery and 6 months after surgery were collected and analyzed. Measurement data with normal distribution were represented as mean±standard deviation( ± s), and the comparison before and after surgery was conducted using repeated-measures analysis of variance test. Measurement data with skewed distribution were represented as M( Q1, Q3). Results:All 32 patients were followed up for 6 months. The operation time was (209.6±49.0) min, and the blood loss was (462.9±298.3) mL. 14 patients(43.8%) were treated with blood transfusion. The modified Tokuhashi score was 8.09±2.89, and the SINS was 8.81±1.97. The VAS score before surgery, postoperative 1, 3, 6 months were 7.47±0.98, 3.87±0.87, 2.91±0.73 and 2.34±0.60, respectively. ODI score before surgery, postoperative 1, 3, 6 months were 79.13±9.50, 39.14±6.31, 34.43±6.42 and 31.08±4.80, respectively. KPS score before surgery, postoperative 1, 3, 6 months were 49.69±14.70, 64.68±15.02, 71.88±12.81 and 75.63±10.76, respectively. The ASIA grading at 6 months follow-up was improved compared to preoperative baseline. Postoperative complications occurred in 4 cases, including nerve root injury (1 case), bone cement leakage in paravertebral soft tissue (1cases), bone cement leakage in paravertebral vein(1case) and acute thoracic epidural hematoma (1case).Conclusion:Vertebroplasty combined with posterior decompression and internal fixation can effectively relieve pain, relieve the compression of spinal cord and nerve, recover nerve functions, and improve the quality of life of patients with spinal metastatic tumor.

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Objective:To establish a three-dimensional model of locking plate fixation for 42A2 type oblique tibial fractures with different fracture line directions and different angles between the fracture line and the long axis of the tibia. Finite element analysis was used to calculate and analyze the biomechanics of locking plate, screw, and tibia, providing theoretical basis for clinical application.Methods:A healthy adult volunteer, 25 years old, male, with a height of 173 cm and a weight of 69.5 kg, was selected to perform computed tomography (CT) scans on the left tibia. Relevant data were obtained to establish a locking steel plate fixation model for 42A2 type tibia with different oblique fracture line directions and different angles between the fracture line and the long axis of the tibia. Eight hole pure titanium plates were used for fixation, respectively. We compared the Mises stress changes of locking plates, screws, and tibia in different angle fracture models.Results:In the case of a 42A2 type fracture in the left oblique direction with a fracture line from outside to inside, the maximum Mises stress in the tibia was 114 MPa, the maximum Mises stress in the screw was 279.8 MPa, and the maximum Mises stress in the locking steel plate was 302.4 MPa; In the case of a 42A2 type fracture in the right oblique fracture with a fracture line from the bottom to the top, the maximum Mises stress of the tibia was 93.41MPa, the maximum Mises stress of the screw was 353.4 MPa, and the maximum Mises stress of the locking steel plate was 411.8 MPa.Conclusions:Regardless of the oblique fractures in both left and right directions, the maximum stress values are: locking plate>screw>tibia; When the position of the locking steel plate is fixed, the maximum stress values of the locking steel plate and screw are both right oblique fracture>left oblique fracture; And the maximum stress values all increase with the increase of angle.

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Objective:To compare the efficacies of posterior long segment instrumentation combined with transpedicular impaction bone grafting or with bone cement augmentation in treating stage III Kümmell disease.Methods:A retrospective cohort study was conducted to analyze the clinical data of 38 patients with stage III Kümmell disease who were admitted to Zhengzhou Orthopedic Hospital between January 2016 and December 2020. The study included 8 male and 30 female patients, with ages ranging from 59 to 81 years [(68.9±4.9)years]. The vertebral fractures occurred at T 8 in 1 patient, T 11 in 9 patients, T 12 in 10 patients, and L 2 in 10 patients. Seventeen patients underwent posterior long segment instrumentation combined with transpedicular impaction bone grafting (impaction bone grafting group), and 21 patients underwent posterior long segment instrumentation combined with bone cement augmentation (bone cement group). The surgical duration, intraoperative blood loss, and incidences of postoperative complications were compared between the two groups. Additionally, the visual analogue score (VAS), Japanese orthopedic association (JOA) score, and Cobb angle were compared before the operation, at 1 week and 3 months post-operation, and at the final follow-up for both groups. The study also compared bone healing at the last follow-up and postoperative complication rates between the two groups. Results:All the patients were followed up for 24-35 months [(28.7±2.9)months]. The impaction bone grafting group had a surgical duration of (150.7±25.4)minutes and intraoperative blood loss of (285.3±48.6)ml, significantly different from those in the bone cement group [(132.0±21.1)minutes, (251.4±44.8)ml] (all P<0.05). Before the operation, there were no significant differences in the VAS, JOA score, or Cobb angle between the two groups (all P>0.05).The VAS was (3.2±0.8)points, (2.7±0.5)points and (2.2±0.7)points in the impaction bone grafting group and was (2.7±0.6)points, (2.6±0.7)points and (2.4±0.8)points in the bone cement group at 1 week and 3 months post-operation and at the final follow-up, respectively. The VAS in the impaction bone grafting group was significantly higher than that in the bone cement group at 1 week post-operation ( P<0.05); however, no significant differences were found at 3 months post-operation or at the last follow-up (all P>0.05). There was no significant difference in the JOA score between the two groups at 1 week or 3 months post-operation, or at the final follow-up (all P>0.05). The Cobb angle in the impaction bone grafting group was (5.1±1.3)°, (5.9±1.8)° and (6.5±2.5)° at 1 week and 3 months post-operation, and at the final follow-up, significantly lower than that in the bone cement group [(8.4±1.6)°, (12.6±2.1)°, and (14.5±3.3)°] (all P<0.01). All the patients in the impaction bone grafting group achieved bone healing at the last follow-up. One patient in the impaction bone grafting group experienced delayed incision healing, whereas two patients in the bone cement group had poor bone healing. The complication rate was 5.9% (1/17) in the impaction bone grafting group and 9.5% (2/21) in the bone cement group ( P>0.05). Conclusions:Posterior long segment instrumentation combined with transpedicular impaction bone grafting or with bone cement augmentation are both effective in alleviating pain and improving the spinal function for stage III Kümmell disease. The former procedure is associated with longer surgical duration and increased intraoperative blood loss, but it can provide superior correction and maintenance of kyphosis deformity, promoting the healing of the injured vertebrae.

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Objective:To evaluate the efficacy of implant surface culture in identification of pathogens for fracture device-related infection.Methods:A prospective study was conducted to include the eligible patients who were diagnosed with infection after fracture fixation and needed surgical removal of the implants according to treatment principles at Division of Orthopaedics and Traumatology, Department of Orthopaedics and Traumatology, Nanfang Hospital from November 2020 to January 2023. With informed consent, after rinsing with aseptic normal saline twice, their implants were gently covered with a thin layer of tryptone soy agar medium. Thereafter, the implants were incubated at 37 ℃ with 5% CO 2. Changes on the surface and in the surroundings of the implants were observed every day for consecutive 2 weeks to avoid drying up by supplementing the medium when necessary. Once pathogen colonies formed, samples were collected at 3 independent sites using sterile swabs for laboratory identification. Comparisons were made between the samples from implant surface culture and the intraoperative multisite samples from conventional culture. Results:Included were a total of 75 patients [56 males and 19 females with an age of (46.2±15.4) years]. The most common infection site was the tibia (37 cases), and the most common type of implants was plate and screw (59 cases). The positive rate of implant surface culture was significantly higher than that of conventional culture (86.7% vs. 52.0%, P<0.001). 80.5% (29/36) of the negative patients detected by the conventional culture obtained positive results by the implant surface culture; three of the positive patients detected by the conventional culture obtained negative results by the implant surface culture. The culture results were positive by both culture methods in 36 patients, and consistent by both culture methods in 35 patients, yielding a consistent rate of 97.2% (35/36). The time for implant surface culture was significantly shorter than that for conventional culture [1 (1, 2) d versus 3 (3, 4) d] ( P<0.001). Of the 65 positive patients by the implant surface culture, 59 were detected with monomicrobial infection, with Staphylococcus aureus on the top (29 cases). Conclusion:As the implant surface culture, a novel method, may be superior to the conventional culture in a significantly higher positive rate and a shorter culture time, it may be used as an effective adjunct to the conventional culture in identification of pathogens for fracture device-related infection.

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Objective:To evaluate the feasibility, accuracy, effectiveness and safety of a novel manual placement of cervical 7 pedicle screws via the posterior approach of cervicothoracic junction.Methods:A retrospective case series study was conducted to analyze the 35 patients with injury to the lower cervical spine or cervicothoracic junction who had been treated by a novel manual placement of cervical 7 pedicle screws at Department of Orthopedics, The First Affiliated Hospital of Zhengzhou University from March 2015 to July 2021. There were 16 males and 19 females, with an age of (52.7±13.2) years. The core of this placement was to determine the entry point of cervical 7 pedicle screws. After the intersection of the upper edge of the cervical 7 lamina and the medial edge of the superior articular process was recorded as point A while the intersection of the lateral edge of the inferior articular process and the lower edge of the transverse process as point B, the intersection of the outer and middle 1/3 of the AB line was taken as the screw entry point, with the screw placement angle perpendicular to the lamina line or slightly inclined from 30° to 40° to the head side and outward. The length, diameter and placement angle of the cervical 7 pedicle screws were recorded and compared postoperatively between the left and right sides to explore the feasibility of this novel manual placement. According to the Rampersaud method, the screw positions were graded 1 week and 6 months after operation to evaluate the accuracy of this manual placement. The visual analogue scale (VAS) and the Japanese Orthopaedic Association (JOA) score were compared between preoperation, 1 week and 6 months after operation to evaluate the effectiveness of this placement. The postoperative complications were counted to evaluate the safety of this method. Loosening, displacement and breakage of the screws were observed by CT scanning at 6 months after operation.Results:This case series was followed up for (9.8±1.7) months. There was no significant difference in the length, diameter or placement angle of the screws between the left and right sides ( P>0.05). A total of 66 cervical 7 pedicle screws were placed. There was no change in the screw position grading at 1 week or 6 months after surgery. Grade A was achieved in 64 screws, Grade B in 2 screws, and Grade C or D in none. The VAS scores before operation, 1 week and 6 months after operation were respectively 4.4±1.7, 3.8±1.0 and 1.1±1.1, and the JOA scores respectively 6.7±2.2, 13.2±1.5 and 15.3±1.2. The VAS and JOA scores at 1 week and 6 months after operation were significantly improved compared with the preoperative values ( P<0.05). The improvement rates in JOA at 1 week and 6 months after operation were 62.7%±13.3 % and 83.9%±11.6%, respectively. There were no complications related to the placement of cervical 7 pedicle screws; there was no wound hematoma or infection. No loosening, displacement or breakage of the screws was observed by the 6-month follow-up. Conclusion:The novel manual placement of cervical 7 pedicle screws via the posterior approach of cervicothoracic junction is feasible, accurate, effective and safe.