Objective To investigate the relationship between the initial stabil ity and infected loosening of the total hip arthroplasty (THA) prosthesis. Methods From January 2000 to December 2008, 110 cases (110 hips) were treated with THA revision. Among them, 15 cases (15 hips) were confirmed infected loosening. There were 8 males and 7 females with anaverage age of 62 years (range 42-75 years). The infected signs were found from 6 months to 2 years after initial THA. All of them had Tsukayama type IV and late infection, including 6 cases of acetabular infected loosening (5 cases of one-stage and 1 case of two-stage acetabular revision), 7 cases of simple infected loosening of femoral prosthesis (4 cases of one-stage and 3 cases of twostage femoral prosthesis revision), and 2 cases of joint capsule infection and sinus without prosthesis loosening (debridement and continuous irrigation). Results All incisions healed by first intention. Fifteen patients were followed up for 12 to 36 months (average 24 months). In 13 cases of revision, postoperative X-ray films showed that femoral acetabular prostheses were in good position, and had no cl inical and imaging infective signs of loosening. In 2 cases of joint capsule infection, sinus recurred 6 months postoperation without hip joint pain, the function of weight-bearing and walking of hip joint was normal. Harris score increased from preoperative average of 42 to postoperative average of 85; the results were excellent in 4 cases, good in 7 cases, and fair in 4 cases. Conclusion The infection of THA may occur in the whole joint, half-joint or just in joint capsule. The initial stabil ity of the prosthesis would affect the long-term survival of the prothesis. If the prosthesis initial stabil ity is obtained, even if there are infective factors, infections would also be l imited.
Objective To compare the short-term effectiveness of repairing distal tibiofibular syndesmosis with metal screws and absorbable screws. Methods A retrospective analysis was performed on the clinical data of 63 patients with ankle fracture combined with injury of the distal tibiofibular syndesmosis admitted between January 2017 and January 2020. Among them, 31 patients were treated with absorbable screw fixation of the distal tibiofibular syndesmosis (research group) and 32 patients were treated with metal screw fixation of the distal tibiofibular syndesmosis (control group). There was no significant difference in gender, age, cause of injury, surgical side, time from injury to operation, fracture type, preoperative visual analogue scale (VAS) score, and American Orthopaedic Foot & Ankle Society (AOFAS) score between the two groups (P>0.05). The operation time and fracture healing time were recorded and compared between the two groups. X-ray film was taken to evaluate the effect of ankle joint reduction and fixation. Olerud-Molander ankle fracture efficacy score (short for OM score), AOFAS score, and VAS score were used to evaluate the effectiveness. Results There was no significant difference in operation time between the two groups (t=−0.683, P=0.497). In the control group, 1 case of delayed healing and 1 case of poor healing occurred in the lateral incision after operation, which healed after dressing change; the rest of the patients had primary healing of the incision. Patients in both groups were followed up 12-24 months, with an average of 13.8 months. In the control group, 1 patient with fracture of pronation and external rotation walked with full weight bearing after removing the metal screw of the distal tibiofibular syndesmosis at 8 weeks after operation, the anatomical plate of the lateral malleolus was broken, and the lateral malleolus was fixed again and recovered after 5 months; 1 patient had mild ankle pain after operation, and the pain disappeared after removing the metal screw of the distal tibiofibular syndesmosis at 8 weeks. No complication such as nerve and blood vessel injury occurred in all patients. There was no significant difference in fracture healing time between the two groups (t=−1.128, P=0.264). The AOFAS and VAS scores significantly improved in both groups at 12 months after operation (P<0.05). There was no significant difference between the two groups in the OM scores, and the difference of AOFAS and VAS scores between before and after operation (P>0.05). Conclusion Using absorbable screws to repair the distal tibiofibular syndesmosis can effectively restore the ankle acupoint structure, prevent ankle instability, and restore good ankle function. There is no significant difference in effectiveness between absorbable screws and metal screws, and there is no need for secondary operation to remove screws.
ObjectiveTo compare the effectiveness of long and short proximal femoral nail anti-rotation (PFNA) in the treatment of type A2.3 intertrochanteric fracture of femur (IFF). Methods The clinical data of 54 patients with type A2.3 IFF admitted between January 2020 and December 2022 were retrospectively analyzed. According to the length of PFNA nail used in the operation, they were divided into long nail group (PFNA nail length>240 mm, 24 cases) and short nail group (PFNA nail length≤240 mm, 30 cases). There was no significant difference in baseline data such as gender, age, fracture side, body mass index, and time from fracture to operation between the two groups (P>0.05). The operation time, intraoperative blood loss, intraoperative fluoroscopy frequency, intraoperative reduction quality score, fracture healing, and complications of the two groups were recorded and compared. Harris score was used to evaluate the hip function of patients at 1 year after operation. According to the relationship between the fracture line of type A2.3 IFF and the lesser trochanter, the two groups of patients were divided into type Ⅰ(the fracture line extends to the level of the lesser trochanter), type Ⅱ(the fracture line extends to less than 2 cm below the lesser trochanter), and type Ⅲ (the fracture line extends to more than 2 cm below the lesser trochanter), and the postoperative stability and internal fixator loosening of each subtype were evaluated. Results The operation time, intraoperative blood loss, and intraoperative fluoroscopy frequency in short nail group were significantly less than those in long nail group (P<0.05). There was no significant difference in the intraoperative reduction quality score between the two groups (P>0.05). Patients in both groups were followed up 12-18 months, with an average of 13.5 months. The postoperative stability score of short nail group was significantly lower than that of long nail group (P<0.05). The Harris score in the long nail group was significantly higher than that in the short nail group at 1 year after operation (P<0.05), but there was no significant difference in Harris score grading between the two groups (P>0.05). Complications occurred in 3 cases of the long nail group (including 1 case of coxa varus caused by external nail entry point and 2 cases of loose internal fixator), and 7 cases of the short nail group (including 1 case of coxa varus caused by external nail entry point and 6 cases of loose internal fixator). Neither group had any anterior femoral arch damage, there was no significant difference in the incidence of complications between the two groups (P>0.05). The number of type Ⅲ patients was relatively small and not included in the statistics; there was no significant difference in the postoperative stability score and the incidence of internal fixator loosening between the long and short nail groups in type Ⅰ patients (P>0.05). In type Ⅱ patients, the postoperative stability score and the incidence of internal fixation loosening in the long nail group were significantly better than those in the short nail group (P<0.05).Conclusion Long PFNA fixation for type A2.3 IFF has longer operation time and more intraoperative blood loss, but the overall stability of fracture is better after operation. For type A2.3 IFF with fracture line extending to less than 2 cm below the lesser trochanter, long PFNA is used for fixation, although the surgical trauma is large, but the postoperative stability is better than that of short PFNA; for type A2.3 IFF with fracture line extending to the lesser trochanter, there is no significant difference in postoperative stability between long and short PFNAs.
Objective To study operative methods of treating upper cervical spine instability without injury. Methods Twentythree cases were treated by internal fixation with autologous bone grafts. Atlantoaxial arthrodesis were performed in 10 cases with Apofix interlaminar clamp(5 cases), Atlas cable system(3 cases) and Brookes(2 cases). Occipitocervical fusion were performed in the other 13 cases by using of CD-cervical(3 cases), Cervifix(8 cases) and Ustick fixation(2cases). Results All the 23 cases were followed up for 2.5 years in average (ranged from 6 months to 5 years). Solid arthrodesis was obtained in all 23 cases . Six months after operation, of the 20 cases with preoperation nervous lesion, improvement was achieved in 16 cases. According to JOA standard and Hirabashiformula,the rate of improvement was 27.1%.Conclusion Posterior fusion is recommended for upper cervical unstability.
Objective To evaluate the biomechanical stability of a newly-designed Y type pedicle screw (YPS) in osteoporotic synthetic bone. Methods The osteoporotic synthetic bone were randomly divided into 3 groups (n=20). A pilot hole, 3.0 mm in diameter and 30.0 mm in deep, was prepared in these bones with the same method. The YPS, expansive pedicle screw (EPS), and bone cement-injectable cannulated pedicle screw (CICPS) were inserted into these synthetic bone through the pilot hole prepared. X-ray film examination was performed after 12 hours; the biomechanical stability of YPS, EPS, and CICPS groups was tested by the universal testing machine (E10000). The test items included the maximum axial pullout force, the maximum running torque, and the maximum periodical anti-bending. Results X-ray examination showed that in YPS group, the main screw and the core pin were wrapped around the polyurethane material, the core pin was formed from the lower 1/3 of the main screw and formed an angle of 15° with the main screw, and the lowest point of the inserted middle core pin was positioned at the same level with the main screw; in EPS group, the tip of EPS expanded markedly and formed a claw-like structure; in CICPS group, the bone cement was mainly distributed in the front of the screw and was dispersed in the trabecular bone to form a stable screw-bone cement-trabecular complex. The maximum axial pullout force of YPS, EPS, and CICPS groups was (98.43±8.26), (77.41±11.41), and (186.43±23.23) N, respectively; the maximum running torque was (1.42±0.33), (0.96±0.37), and (2.27±0.39) N/m, respectively; and the maximum periodical anti-bending was (67.49±3.02), (66.03±2.88), and (143.48±4.73) N, respectively. The above indexes in CICPS group were significantly higher than those in YPS group and EPS group (P<0.05); the maximum axial pullout force and the maximum running torque in YPS group were significantly higher than those in EPS group (P<0.05), but there was no significant difference in the maximum periodical anti-bending between YPS group and EPS group (P>0.05). Conclusion Compared with EPS, YPS can effectively enhance the maximum axial pullout force and maximum rotation force in the module, which provides a new idea for the design of screws and the choice of different fixation methods under the condition of osteoporosis.
Although metal blocks have been widely used for reconstructing uncontained tibial bone defects, the influence of their elastic modulus on the stability of tibial prosthesis fixation remains unclear. Based on this, a finite element model incorporating constrained condylar knee (CCK) prosthesis, tibia, and metal block was established. Considering the influence of the post-restraint structure of the prosthesis, the effects of variations in the elastic modulus of the block on the von Mises stress distribution in the tibia and the block, as well as on the micromotion at the bone-prosthesis fixation interface, were investigated. Results demonstrated that collision between the insert post and femoral prosthesis during tibial internal rotation increased tibial von Mises stress, significantly influencing the prediction of block elastic modulus variation. A decrease in the elastic modulus of the metal block resulted in increased von Mises stress in the proximal tibia, significantly reduced von Mises stress in the distal tibia, decreased von Mises stress of the block, and increased micromotion at the bone-prosthesis fixation interface. When the elastic modulus of the metal block fell below that of bone cement, inadequate block support substantially increased the risk of stress shielding in the distal tibia and fixation interface loosening. Therefore, this study recommends that biomechanical investigations of CCK prostheses must consider the post-constraint effect, and the elastic modulus of metal blocks for bone reconstruction should not be lower than 3 600 MPa.
Objective To investigate the possible mechanism and fracture stability of subtypes of type B Hangman’s fracture by using imaging observation. Methods Patients with type B Hangman’s fractures admitted to multiple centers between January 2008 and October 2023 were selected as the research objects. The clinical data and imaging data of patients who met the selection criteria were extracted. The patients’ age, gender, cause of fracture, disease duration, visual analogue scale (VAS) score of neck pain, neck disability index (NDI), and American Spinal Injury Association (ASIA) classification of spinal cord function were collected. Based on the imaging data, the anatomical structure of the contralateral superior articular process fracture, the relationship between the superior articular process fracture line and the position of the odontoid process, the associated posterior vertebral wall fracture and its classification, the incidence of vertebral arch floating and C2, 3 instability were observed. The superior articular fracture angle (SAFA), superior articular fracture displacement distance (SAFD), and C2 vertebral body rotation (VBRA) were measured. According to the anatomical structure of the contralateral superior articular process fracture, the patients were divided into a pedicle fracture group (POA group), a inferior articular process fracture group (IAP group), and a laminar fracture group (CSL group). The baseline data and imaging indexes were analyzed between groups, and the imaging anatomical characteristics of each subtype of fracture were observed to explore its possible mechanism and fracture stability.Results A total of 86 cases of type B Hangman’s fractures were collected. There were 67 males and 19 females. The mean age was 51.0 years (range, 21-78 years). There were 48 cases of pedicle fracture (POA group), 25 cases of inferior articular process fracture (IAP group), and 13 cases of laminar fracture (CSL group). There was no significant difference in age, gender, cause of fracture, disease duration, VAS score of neck pain, and NDI between groups (P>0.05). However, the incidence of spinal cord injury in POA group was the highest (P<0.05). The incidences of superior articular process fracture line posterior to the odontoid process and posterior vertebral wall fracture in POA group were the highest (P<0.05). The incidences of vertebral arch floating and C2, 3 instability in IAP group were the highest (P<0.05). There were significant differences in SAFA and VBRA between groups (P<0.05). There was no significant difference in SAFD between groups (P>0.05). The differences in the incidences of fracture displacement>3 mm and VBRA>5° between groups were significant (P<0.05). There were 78 cases of unstable Hangman’s fracture, including 2 cases of simple C2、3 instability, 22 cases of simple axis rotation and displacement instability, 8 cases of simple vertebral arch floating instability, and the rest of the patients had two or more types of instability. Conclusion The mechanism of different subtypes of type B Hangman’s fracture may be that the lateral mass of the rotation of the atlas applied the overextension compression force to the unilateral superior articular process of the axis vertebra, and the contralateral pedicle, inferior articular process and lamina fractures were caused by direct violence or/and rotational violence to different degrees. The decomposition of this type of fracture into C2, 3 intervertebral, axis vertebra body displacement and rotation and vertebral arch floating instability is beneficial to the treatment and surgical approach selection.
Objective To assess the effectiveness of suture button fixation Latarjet procedure under total arthroscopy for anterior shoulder instability with severe bone defects. MethodsThe clinical data of 15 patients with severe bone defects and anterior shoulder instability treated with suture button fixation Latarjet procedure under total arthroscopy between June 2020 and February 2023 was retrospectively analyzed, including 11 males and 4 females, with an average age of 31.1 years (range, 20-54 years). Three-dimensional CT showed that the average glenoid bone defect was 24.4% (range, 16.3%-35.2%). The average number of shoulder dislocation was 4.2 times (range, 3-8 times). The disease duration ranged from 6 to 21 months with an average of 10.6 months. The operation time and intraoperative blood loss were recorded. The pain relief was evaluated by visual analogue scale (VAS) score, and the functional recovery of shoulder joint was evaluated by Rowe score, Walch-Duplay score, and American Association for Shoulder and Elbow Surgery (ASES) score before and after operation. The range of motion (ROM) of the shoulder joint was assessed, including active flexion, lateral external rotation, abduction 90° external rotation, and internal rotation. Three-dimensional CT was performed at 6 months after operation and at last follow-up to observe the absorption of bone graft, the position of bone graft and glenoid, and the healing of bone graft. Results The operation was successfully completed in all patients. The operation time was 85-195 minutes, with an average of 123.0 minutes. The intraoperative blood loss was 20-75 mL, with an average of 26.5 mL. All patients were followed up 13-32 months, with an average of 18.7 months. During the follow-up, there was no serious complication such as shoulder joint infection, joint stiffness, or vascular and nerve injury. One patient had partial absorption of the transplanted bone and bone nonunion at 3 months after operation, but the pain of the shoulder joint relieved at last follow-up, and no redislocation of the shoulder joint occurred; no obvious bone fracture or dislocation of the shoulder joint was found in the other patients. Bone union was achieved at 6 months during follow-up. At last follow-up, the VAS score, Rowe score, Walch-Duplay score, and ASES score significantly improved when compared with those before operation (P<0.05), while the ROM of active flexion, lateral external rotation, abduction 90° external rotation, and internal rotation of the shoulder joint was not significantly different from those before operation (P>0.05).ConclusionSuture button fixation Latarjet procedure under total arthroscopy can improve shoulder joint function in patients with severe anterior shoulder instability caused by bone defects, and imaging also indicates satisfactory placement of transplanted bone blocks.
ObjectiveTo evaluate the stability of the fixation technique for the crossed rods consisting of occipital plate and C2 bilateral lamina screws by biomechanical test.MethodsSix fresh cervical specimens were harvested and established an atlantoaxial instability model. The models were fixed with parallel rods and crossed rods after occipital plate and C2 bilateral laminae screws were implanted. The specimens were tested in the following sequence: atlantoaxial instability model (unstable model group), under parallel rods fixation (parallel fixation group), and under crossed rods fixation (cross fixation group). The range of motion (ROM) of the C0-2 segments were measured in flexion-extension, left/right lateral bending, and left/right axial rotation. After the test, X-ray film was taken to observe the internal fixator position.ResultsThe biomechanical test results showed that the ROMs in flexion-extension, left/right lateral bending, and left/right axial rotation were significantly lower in the cross fixation group and the parallel fixation group than in the unstable model group (P<0.05). There was no significant difference between the cross fixation group and the parallel fixation group in flexion-extension and left/right lateral bending (P>0.05). In the left/right axial rotation, the ROMs of the cross fixation group were significantly lower than those of the parallel fixation group (P<0.05). After the test, the X-ray film showed the good internal fixator position.ConclusionThe axial rotational stability of occipitocervical fusion can be further improved by crossed rods fixation when the occipital plate and C2 bilateral lamina screws are used.
ObjectiveTo explore the effects of core stable training on cervical vertebrae pain, cervical function and balance ability in patients with neck type cervical spondylopathy (NTCS).MethodsFrom January to August 2018, 98 patients with NTCS were treated. According to the odd and even bed numbers, 49 patients were enrolled in the observation group and 49 were in the control group. The patients in the control group was given Kinesio tape treatment, and the observation group was given core stability training based on the treatment of the control group. Cervical vertebrae pain was assessed by Visual Analogue Scale (VAS), Clinical Assessment Scale for Cervical Spondylosis (CASCS) and Neck Disability Index (NDI); cervical vertebra activity were used to assess the cervical; the Berg Balance Scale (BBS) was used to assess patients’ balance before intervention and at the 4th week of intervention. The incidence of complications during the intervention and the effective of treatment 4 weeks after intervention were recorded. The recurrence rate 6 months after the intervention was recorded.ResultsThere were no significant difference in CASCS, NDI, VAS, and BBS scores between the two groups before intervention (P>0.05). At the 4th week of the intervention, the CASCS and BBS scores of the two groups were higher than those before the intervention, and the VAS and NDI scores were lower than those before the intervention (P<0.05); and the CASCS and BBS scores in observation group at the 4th week of the intervention were higher than that of control group, and VAS and NDI scores were lower than those of the control group (P<0.05). There was no significant difference in the activity of the cervical vertebrae before intervention in both of the two groups (P>0.05). At the 4th week of the intervention, the activity of the cervical vertebrae in all directions was bigger than that of before the intervention in both of the two groups (P<0.05), and that in observation group were bigger than that of the control group (P<0.05). The effective rate at the 4th week in the observation group (95.92%) was higher than that in the control group (81.83%)(P<0.05). The recurrence rate 6 months after intervention in the observation group (6.38%) was lower than that in the control group (22.50%) (P<0.05).ConclusionCore stability training can relieve cervical spondylosis in NTCS patients, and improve the cervical function and patients’ balance; it has high safety and stable efficacy.