OBJECTIVE: To explore the differences in the implantation safety and stability of a S ₁ alar-iliac screw (S1AIS) or S2AIS for sacroiliac joint fixation, providing reference for selecting appropriate internal fixation in clinical practice. METHODS: Patients who underwent pelvic CT examination between January 2024 and December 2024 were selected. CT data from 80 patients with normal pelvic structure who met the selection criteria were included in a 1∶1 male to female ratio. CT digital reconstruction technology was used to measure the transverse and longitudinal diameters of the S1AIS and S2AIS insertable ranges, as well as the length, width, and sacral side length of the screw trajectory. The pelvic CT data from 30 patients were randomly selected based on a 1∶1 male to female ratio for three-dimensional (3D) printing of pelvic samples. The S1AIS/S2AIS with a diameter of 6.5 mm and 8.0 mm were implanted at the optimal entry/exit points on the left and right sides, respectively, to observe the perforation of the screw trajectory. The pelvic CT data from 1 patient was randomly selected for 3D printing of 10 pelvic samples to simulate Tile C2 fracture. They were divided into S1AIS group ( n=5) and S2AIS group ( n=5), with one S1AIS and one S2AIS fixation used for posterior sacroiliac joint separation, and the specimen stiffness and maximum load were measured by using an electric tension torsion dual axis universal mechanical tester. RESULTS: The anatomical parameter measurement showed that there was no significant difference in the length and width of the screw trajectory between S1AIS and S2AIS ( P>0.05), but the transverse and longitudinal diameters of the insertable ranges, as well as the sacral side length of the screw trajectory, were all greater than those of S2AIS, with significant differences ( P<0.05). After simulating the implantation of S1AIS and S2AIS with a diameter of 6.5 mm in pelvic specimens, no screw penetration was observed. Both S1AIS and S2AIS with a diameter of 8.0 mm showed screw penetration, with S2AIS having a higher incidence of posterior lateral sacral cortical penetration (46.7%) than S1AIS (3.3%) ( P<0.05). The biomechanical test showed that the stiffness and maximum load of S2AIS were significantly lower than those of S1AIS ( P<0.05). CONCLUSION As a method to fix the sacroiliac joint, the S1AIS has a larger insertable range, a longer sacral side length of the screw trajectory, a lower incidence of posterior lateral cortical rupture of the sacrum, and a greater fixation strength than S2AIS. Therefore, the implantation safety and fixation stability of the S1AIS are superior to S2AIS, and a diameter less than 8.0 mm screws should be selected as S2AIS for Chinese people.
Humans ; Bone Screws ; Sacroiliac Joint/diagnostic imaging* ; Male ; Female ; Sacrum/diagnostic imaging* ; Fracture Fixation, Internal/instrumentation* ; Ilium/diagnostic imaging* ; Tomography, X-Ray Computed ; Middle Aged ; Adult ; Printing, Three-Dimensional ; Aged

Objective:To explore the optimal insertion point of reverse sacral alar-iliac screws (RSAIS) in sacroiliac joint fixation for Tile type C pelvic fracture and the effectiveness of its preliminary clinical application.Methods:CT data from 90 patients with no abnormal pelvic structures in the Radiology Department database of Liyang People's Hospital from January 2022 to January 2023 were selected. There were 45 males and 45 females, aged 21-69 years [(45.5±6.4)years]. With CT digital reconstruction technology, the RSAIS fixation was simulated and the anterior insertable area was measured. Five insertion points were at the ilium-acetabular recess in the area superior posterior to the acetabulum (A1), at 1 cm (A2) and 2 cm (A3) posterior transversal to A1, at 1 cm (A4) and 2 cm (A5) inferior longitudinal to A1. With the entry point of S 1 pedicle screw as the exit point, the transverse and sagittal CT scans were conducted on 5 screw trajectories of anterior posterior lines (corresponding to five groups). The anatomical parameters of the screw trajectories, including the length, width and height of the screw trajectories were measured by two observers independently and the intraclass correlation coefficient (ICC) between the observers was analyzed. Tile type C pelvic fracture models were established from 20 3D-printed L 5-pelvis-femur specimens and divided into 5 groups, with 4 specimens in each group. The anterior rings were fixed with cross screws while the posterior rings with one RSAIS in each group using one of the aforementioned 5 screw trajectories. The overall displacement and local displacement of the sacroiliac space under 300 N vertical load in all the groups were measured with a biomechanical machine. The screw trajectory was designed according to the optimal insertion point shown in the above anatomical measurements and mechanical experiments. An RSAIS with a diameter of 7.3 mm was inserted percutaneously to treat a patient with Tile type C1 pelvic fracture. The fluoroscopy time of screw insertion and screw position were recorded as well as bone reunion, numerical rating scale for pain, Oswestry dysfunction index (ODI) and Majeed functional score of pelvic fracture at the last follow-up. Results:The anterior insertable area was (1236.64±12.04)mm 2. The trajectory lengths for the three transversal insertion points gradually decreased from front to back, with A1 being the longest (104.9±10.4)mm, followed by A2 (98.5±9.8)mm and A3 the shortest (92.7±9.7)mm ( P<0.01), while there were no significant differences in the widths or heights ( P>0.05). There were no significant differences in the length, width or height of the screw trajectories of the three longitudinal insertion points (groups A1, A4 and A5) ( P>0.05). Compared with A4 and A5, A1 was farther from the margin of the acetabulum. The range of ICC of the anatomical parameters of the 3 screw trajectories measured by the two observers was 0.88-0.98, 95% CI 0.90, 0.96, and 95% CI 0.95, 0.99, indicating high consistency. After the screws were placed and fixed at the 3 transversal insertion points, the overall displacement and local displacement of the sacroiliac space of groups A1, A2 and A3 gradually increased from front to back. They were (2.93±0.09)mm and (1.49±0.14)mm in group A1, (3.14±0.12)mm and (1.63±0.54)mm in group A2 and (3.23±0.12)mm and (1.67±0.67)mm in group A3 respectively. There was a significant difference in the overall displacement among three groups ( P<0.01), while the local displacement of the sacroiliac space in group A1 was decreased compared with that of group A2 and A3 ( P<0.01). After the screws were placed and fixed at the 3 longitudinal insertion points, there were no significant differences in the overall displacement and local displacement of the sacroiliac space of group A1, A4 and A5 ( P>0.05). The fluoroscopy time of RSAIS inserted from A1 for the treatment of patients with Tile C1 pelvic fracture was 66 seconds, with fine screw position. At the last follow-up, the fracture was healed, with numerical rating scale for pain decreased from 6 points preoperatively to 1, ODI improved from 41 preoperatively to 18, and the Majeed functional score of 81 points. Conclusions:For Tile type C pelvic fracture, the screw trajectory from the iliac-acetabular recess located in the superior anterior part of the insertable area is the longest, with the best stability and relatively good safety of the screw, making it the optimal insertion point for RSAIS. The effect of preliminary clinical application of RSAIS from the optimal insertion point is satisfactory.

Objective:To investigate the rationality and surgical errors in countermeasures against difficult removal of screws so as to provide reference for standardization of technical procedures.Methods:A retrospective study was conducted to analyze the data of 99 patients who had encountered difficult removal of screws in operative removal of internal fixation at Department of Orthopaedics, Wuxi NO.9 People's Hospital Affiliated to Suzhou University from January 2018 to May 2022. There were 62 males and 37 females with an average age of 38.8±14.7 years. Their internal fixation time ranged from 7 months to 11 years. The irrationality was defined as insufficient preoperative preparation or a countermeasure that failed to follow the surgical indications or scientific principles of minimal injury or priority of simplicity. A surgical error was defined as unnecessary injury, failed removal or complications related to operation. Cases of irrationality and surgical errors were analyzed to find associations between them.Results:The operative removal was successful in 92 cases and failed in 7 cases. Of the patients who experienced difficult removal of screws, irrationality was found in 26.3% (26/99) and a surgical error or errors occurred in 28.3% (28/99). In the patients with countermeasure irrationality, the incidence of surgical errors was 53.9% (14/26) while in those without countermeasure irrationality, the incidence of surgical errors was 19.2% (14/73), showing a statistically significant difference ( χ2=11.360, P<0.001). In the patients with surgical errors, the incidence of countermeasure irrationality was 64.3% (18/28) while in the patients without surgical errors, the incidence of countermeasure irrationality was and 11.3% (8/71), showing a statistically significant difference ( χ2=29.148, P<0.001). In the patients with failed removal, the rate of countermeasure irrationality was 85.71% (6/7) while in those with successful removal, the rate of countermeasure irrationality was 21.7% (20/92), showing a statistically significant difference ( χ2=13.748, P<0.001). Conclusions:Close relationships exist between countermeasure irrationality, surgical errors and failed removal. The higher proportion of countermeasure irrationality, the higher possibility of surgical errors. Therefore, following the rationality principle may avoid or reduce surgical errors in difficult removal of screws.

Objective:To investigate the advantages and disadvantages of percutaneous compression plate (PCCP) for femoral neck fractures in the elderly patients.Methods:A retrospective study was conducted of the 31 elderly patients with femoral neck fracture who had been treated with PCCP from January 2012 to December 2018 at Orthopaedic Department, The First People's Hospital of Yancheng, Orthopaedic Department, The Ninth People's Hospital of Wuxi and Department of Orthopaedics, The People's Hospital of Wuxi. They were 16 men and 15 women, aged from 65 to 80 years (average, 70.5 years). By the Garden classification, 7 cases were type Ⅱ, 15 cases type Ⅲ and 9 cases type Ⅳ; by the Singh index, 4 cases were level Ⅲ, 11 cases level Ⅳ, 10 cases level Ⅴ and 6 cases level Ⅵ. The time from injury to operation ranged from 3 to 14 days (average, 5.8 days). The operation time, intraoperative blood loss, fracture reduction, fracture union time, complications and functional recovery of the hip were observed.Results:The operation time averaged 73.4 min and intraoperative blood loss 116.4 mL. At one week after operation, the Garden alignment index was level Ⅰ in 25 cases and level Ⅱ in 6. Superficial incision infection was noted in one case intraoperatively. Follow-ups for the 31 patients ranged from 12 to 47 months (mean, 18.9 months). All the fractures united after 4.9 months on average (from 4 to 8 months). Delayed union occurred in 2 cases, neck shortening in 12 cases, and avascular necrosis of femoral head in 3 displaced subcranial fractures 2 of which were high shear ones. The necrosis of femoral head was treated by arthroplasty in 2 and by conservative treatment in one. The Harris hip scores at the last follow-up for the 31 patients averaged 90.9 (from 75 to 100), giving 15 excellent, 12 good and 4 fair cases and an excellent to good rate of 87.1% (27/31).Conclusions:In treatment of femoral neck fractures in the elderly patients, PCCP has advantages of allowing early weight-bearing after operation, a high rate of fracture union, limited complications and quick and fine functional recovery of the hip. However, it should be used with caution in patients with severe osteoporosis, displaced subcranial or high shear fracture.

Objective:To compare in vivo versus in vitro fabrication of bone cement spacers in the treatment of bone defects by Masquelet technique. Methods:The data of 128 patients were analyzed retrospectively who had been treated for bone defects by Masquelet technique at Department of Orthopedics, Wuxi No. 9 People’s Hospital from January to August 2019. They were 74 males and 54 females, aged from 13 to 77 years. Their bone defects were traumatic in 54 cases and infectious in 74 cases. In 76 of them ( in vivo group), after a bone cement spacer was implanted into a bone defect during its dough phase, it was fabricated in vivo to form a cylindrical structure which was as large as or slightly larger than the defect size. In the other 52 cases ( in vitro group), before a bone cement spacer was implanted into a bone defect, it was fabricated in vivo during its dough phase into a cylindrical or block or bead chain or spherical form which was naturally solidificated at room temperature. The 2 groups were compared in terms of spacer filling time, bone healing time, delayed healing rate, infection control rate, spacer removal time, incidence of induced membrane or broken end bone lesion, as well as upper limb function evaluated by the Disability of the Arm, Shoulder and Hand Questionnaire (DASH) and the Paley lower limb grading at the last follow-up. Results:The 2 groups were comparable because there was no significant difference between them in gender, age, ratio of infected to non-infected cases, combined injuries, comorbidities or number of operations ( P>0.05). All the patients were followed up for 12 to 50 months (mean, 18.6 months). There were no significant differences between the 2 groups in spacer filling time, bone healing time, delayed healing rate, infection control rate or functional recovery for upper or lower limbs or for large or small bone defects (all P>0.05). In the in vivo group, for upper and lower limbs and for large and small bone defects respectively, the spacer removal time [(3.6±1.0) min, (4.1±1.1) min, (4.0±1.1) min and (3.9±1.0) min] and the incidence of induced membrane or broken end bone lesion [48.1%(13/27), 73.5%(36/49), 82.6%(39/46) and 66.7%(20/30)] were significantly longer or higher than those in the in vitro group [all (0.4±0.2) min; 3.2%(1/31), 9.5%(2/21), 0 (0/21) and 0 (0/31)] (all P<0.05). Conclusions:In the treatment of bone defects by Masquelet technique, in vivo and in vitro fabrication of bone cement spacers may lead to similar therapeutic effects. In vivo fabrication may be more suitable for lower limb, large or unstable bone defects but the spacer is not easy to remove and the induced membrane or bone ends are likely to get injured while in vitro fabrication may be more suitable for partial, small or upper limb defects because it may produce a variously shaped spacer.

Objective:To characterize the radial head fracture combined with capitulum cartilage injury (CCI).Methods:The data of 110 patients were analyzed retrospectively who had been treated for radial head fracture at Department of Orthopaedics, The Ninth People's Hospital of Wuxi from January 2011 to May 2020. They were 62 males and 48 females, aged from 17 to 74 years (average, 44.10 years). According to the finding of intraoperative exploration whether CCI was complicated or not, they were assigned into a CCI group and a CCI-free group. The diagnosis, location, size, type, operation method and postoperative recovery of CCI were observed in CCI group. The 2 groups were compared in terms of preoperative general data, range of forearm motion before and after operation and functional recovery of the limb by Mayo elbow performance score (MEPS).Results:CCI was complicated in 25 cases (type Ⅰ in 7 ones, type Ⅱ in 12 ones and type Ⅲ in 6 ones), involving all Mason types of radial head fracture, and located at the lateral capitellum in 13 cases, at the posterolateral capitellum in 9 cases and at the anterolateral capitellum in 3 cases. CCI was diagnosed before operation in 13 cases by physical examination after local anesthesia and imaging examination with a rate of 48% (12/25) for missed diagnosis. The preoperative flexion and extension (61.8°±13.7°) and rotation (60.0°±24.2°) in CCI group were significantly less than those in CCI-free group (77.7°±23.0° and 79.9°±21.9°) ( P<0.05); the Mason types of radial head fracture in CCI group were significantly more serious than those in CCI-free group ( P<0.05). There was no significant difference between the 2 groups in age, gender, combined injury, treatment of radial head fracture, follow-up time, range of forearm motion at the last follow-up or MEPS score ( P>0.05). Conclusions:CCI was complicated in 22.73%(25/110) of the radial head fractures in this cohort and found in all Mason types of radial head fracture, and mostly located at the lateral and posterolateral capitellum. CCI is likely to be missed by imaging examination. In patients with mild radial head fracture and suspected CCI, positive physical examination after local anesthesia is valuable for diagnosis of CCI complication and operative indication. Care should be taken to detect CCI complication by intraoperative exploration in surgery of radial head fracture.

Objective:To investigate the effect and indications of pedicled myocutaneous flap and modified Masquelet technique in the repair of diabetic soft tissue and tibial bone defects.Methods:From January, 2017 to October, 2019, data of surgical treatment of 20 patients with diabetic soft tissue and tibial bone defects were retrospectively studied. The detects were repaired by the pedicled myocutaneous flap combined with modified Masquelet technique. There were 13 males and 7 females aged 40 to 65(average 51) years old. Preoperative ultrasound and CTA had confirmed that there was no occlusion in anterior and posterior tibial arteries. After debridement, the bone defect was 4-9 cm in length and the soft tissue defect was 3 cm×6 cm to 7 cm×10 cm. The initial antibiotic loaded bone cement filling of the bone and soft tissue defects was carried out. Then at 7-10 days later, had the bone cement placed earlier removed the remaining spaces of bone defect were again filled by antibiotic loaded bone cement. Meanwhile, the pedicled myocutaneous flap was transferred to repair the wound. The second stage of Masquelet technique was performed later, with an interval of 8-12(mean 9) weeks. The healing of wound and bone defect, and the complications were recorded. At 12 months after the surgery, the healing and appearance of the flap were evaluated by the standard proposed by Zhang Hao, and the functional recovery of the adjacent joint was evaluated by Johner-Wruhs standard. The treatment was considered successful when the symptoms were disappeared and no recurrence occurred.Results:All patients entered 13 to 28 months of follow-up, 20 months in average. The healing time for bone defect was 6-11 (average 9.0) months. All myocutaneous flaps survived with 18 flaps healed in the stage one and 2 delayed healing. Nine flaps appeared almost normal and 11 shown bloating. Seventeen flaps were found with partial sensation and 3 without sensation at all. The temperature of 7 flaps was found normal and 13 were slightly lower. Fourteen donor site scars were mild and 6 were obvious. The overall curative effect was satisfactory. Two patients had recurred infection. The rates of excellent and good functional recovery, infection control and success of treatment were at 90%(18/20) for each.Conclusion:Pedicled myocutaneous flap combined with modified Masquelet technique can repair diabetic soft tissue and tibial bone defects. It has a good therapeutic effect for short and medium terms.

Objective:To investigate the therapeutic efficacy of Ilizarov bone shortening-lengthening technique for tibial defects of bone and soft tissue without vascular injury.Methods:A retrospective analysis was made of the 28 patients who had been treated by Ilizarov bone shortening-lengthening technique at Department of Orthopaedics, Wuxi No.9 People's Hospital from January 2007 to October 2017 for tibial de-fects of bone and soft tissue without vascular injury.They were 20 males and 8 females, aged from 18 to 69 years (average, 36.4 years).By the Gustillo classification, 5 cases belonged to type Ⅱ, 6 to type ⅢA and 17 to type ⅢB.Infection was complicated in 17 cases.After debridement or epluchage, the area of skin defects ranged from 4 cm × 3 cm to 16 cm × 5 cm and the length of bone defects from 4.5 to 11.0 cm (average, 6.9 cm).The wound healing, bone healing, functionary recovery of lower extremity and complications were observed postoperatively.Bone healing and functional recovery of lower extremity were evaluated according to the grading of Association for the Study and Application of the Method of Ilizarov (ASAMI).The complications associated with Ilizarov technique were assessed according to the Paley criteria.Results:The follow-up for all the patients lasted from 12 to 45 months (average, 20.5 months).The healing time for wounds ranged from 13 to 35 days (average, 21.9 days), the healing time for lengthened bone from 6 to 12 months (average, 8.9 months), and the healing time for bone defects at the dock sites from 6 to 11 months (8.3 months).According to the ASAMI grading, the bone healing was excellent in 21 cases and good in 7, giving an excellent to good rate of 100%(28/28) while the functionary recovery of lower extremity was excellent in 10 cases, good in 15, fair in 2 and poor in one, giving an excellent to good rate of 89.3%(25/28).The incidence was 14.3%(4/28) for major complications after Ilizarov surgery, 57.1%(16/28) for minor complications, 60.7%(17/28) for overall complications, and 1.7 times for each case.Conclusion:In the treatment of tibial defects of bone and soft tissue without vascular injury, Ilizarov bone shortening-lengthening technique can deal with the difficulties in repair of soft tissue defects, characterized by simplified wound closure, fast and improved bone healing at the dock sites, reduced complications and satisfactory functionary recovery of lower extremity.

Objective To investigate the clinical effects of treating traumatic lesions of the popliteal artery by staged stretching.Methods From July 2011 to March 2016,29 patients with traumatic lesion of the popliteal artery underwent staged stretching after direct end to end anastomosis at Department of Orthopaedics,The 9th People's Hospital of Wuxi.They were 19 males and 10 females,with a mean age of 38.3 years (range,from 16 to 61 years).The average length of popliteal artery lesions was 3.7 cm (range,from 2 to 5 cm).After the keen joint was immobilized at flexion by external fixation,direct end to end anastomosis was performed with a proper segmental vascular freedom.From 4 weeks after operation,the popliteal artery was stretched stage by stage to its original length by gradual adjustment of the external fixation till the knee joint was fully extended.The color,skin temperature,pulp tension and capillary reaction of the toes were closely observed after surgery.CT angiography (CTA) was performed 6 months after surgery.The active range of motion was assessed at 12 months after surgery for the knee and ankle joints on the injured limb.Results All the patients were available for an average follow-up of 2 years (range,from 1 to 3 years).Blood supply was good for all the affected limbs.The staged stretching of the popliteal artery resulted in no rupture of any anastomotic stoma or no thrombus.CTA at 6 months after surgery showed fine patency of the popliteal artery and no formation of false aneurysm or arteriovenous fistula.At 12 months after surgery,the knee function was excellent in 15 cases,good in 10 and fair in 4;the ankle function was excellent in 18 cases,good in 8 and fair in 3.Conclusion Staged stretching is a safe,convenient and effective treatment of traumatic lesions of the popliteal artery.

Objective To compare the effects of bone transport versus induced membrane technique for large segmental tibial defects.Methods The clinical data were analyzed retrospectively of 89 patients with large segmental tibial defect who had been treated at Department of Orthopaedics,Wuxi No.9 People's Hospital from June 2005 to February 2017 using bone transport or induced membrane technique.They were 58males and 31 females,aged from 13 to 74 years (average,38.0 years).The bone transport group had 59cases and the induced membrane technique group 30 cases.The 2 groups were compared in terms of preoperative general data and postoperative bone nonunion,bone healing time,complications and functional recovery of the adjacent joint.Results There were no statistically significant differences between the 2groups in terms of age,gender,cause or type of defects,associated injury,course of disease,functionary scores of the adjacent joint or number of operations,showing compatibility between the 2 groups (P ＞ 0.05).All the patients were followed up for 12 to 48 months (average,20 months).The bone transport group had significandy longer clinical healing time (14.7 ± 5.4 months) and significantly higher incidences of major complications (50.8％),minor complications (57.6％) and overall complications (83.1％) than the induced membrane technique group (11.2 ± 2.8 months,16.7％,26.7％ and 30.0％,respectively) (P ＜ O.05),but significantly lower functionary scores of the adjacent joint (86.4 ± 5.0 points) than the induced membrane technique group (88.8 ± 4.9 points) (P ＜ 0.05).Conclusions Both bone transport and induced membrane technique are effective repairs for large segmental tibial defects.However,induced membrane technique may be superior to bone transport in terms of bone healing,complications and functional recovery.