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find Keyword "internal fixation" 282 results
  • Indirect reduction technique via Nice knot for transverse fracture of patella

    ObjectiveTo assess the outcomes in indirect reduction technique via Nice knot for transverse patellar fractures.MethodsThe clinical data of 25 patients with transverse patellar fractures meeting the inclusion criteria between January 2017 and December 2018 were retrospectively analyzed. The patients were divided into trial group (n=13) and control group (n=12) according to different intraoperative reduction methods. No significant difference was found in gender, age, affected side, cause of fracture, classification, or the time from injury to operation between the two groups (P>0.05). In the trial group, No.2 suture was used to cross the quadriceps tendon and patellar tendon to construct the Nice knot, then the suture was tightened to make the distal and proximal fracture segments contact in an indirect reduction pattern. Depend on Nice knot’s sliding compression and self-stabilizing function, the suture mesh created an anterior tension band as a temporary fixation. In the control group, Weber’s clamp was used to hold the fracture segments directly and fixed temporarily. After reduction, terminal fixation was conducted using a titanium Kirschner wire with titanium cable in both groups. The operation time, intraoperative blood loss, follow-up time, fracture healing time, and complications were recorded and compared in the two groups. At last follow-up, the knee function was evaluated according to the Böstman scoring criteria for efficacy in patellar fractures.ResultsThe operation time in the trial group was significantly shorter than that in the control group (t=−2.165, P=0.041). There was no significant difference of intraoperative blood loss between the two groups (t=0.514, P=0.612). The incisions of the two groups healed by first intention. All the patients were followed up 12-16 months, with an average of 14.4 months, no significant difference was found in the follow-up time between the two groups (t=−0.309, P=0.760). One patient in the control group developed soft tissue irritation symptoms at 1 day after operation, and no special treatment was given, the symptoms disappeared at 2 months after operation. The fractures of the two groups healed at the 12-week follow-up. During the follow-up, there was no complication such as loosening and fracture of titanium cables and tendon tissue calcification. At last follow-up, the Böstman score presented no significant difference between the two groups (t=−0.086, P=0.932). In the trial group, an 80-year-old female patient was evaluated as good (score, 27) due to atrophy of the quadriceps femoris, leg weakness, and affected stair climbing, and the rest 24 patients were all evaluated as excellent.ConclusionThe indirect reduction with Nice knot can shorten the operation time in the treatment of transverse patellar fractures, and obtain good effectiveness.

    Release date:2021-06-30 03:55 Export PDF Favorites Scan
  • Comparison of short-term effectiveness of metal screws and absorbable screws in repair of distal tibiofibular syndesmosis

    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.

    Release date:2022-08-29 02:38 Export PDF Favorites Scan
  • Effectiveness of guide plate with mortise-tenon joint structure combined with off-axis fixation in treatment of Pauwels type Ⅲ femoral neck fractures

    Objective To investigate the effectiveness of using 3 hollow compression screws combined with 1 screw off-axis fixation under the guidance of three-dimensional (3D) printed guide plate with mortise-tenon joint structure (mortise-tenon joint plate) for the treatment of Pauwels type Ⅲ femoral neck fractures. Methods A clinical data of 78 patients with Pauwels type Ⅲ femoral neck fractures, who were admitted between August 2022 and August 2023 and met the selection criteria, was retrospectively analyzed. The operations were assisted with mortise-tenon joint plates in 26 cases (mortise-tenon joint plate group) and traditional guide plates in 28 cases (traditional plate group), and without guide plates in 24 cases (control group). There was no significant difference in the baseline data of gender, age, body mass index, cause of injury, and fracture side between groups (P>0.05). The operation time, intraoperative blood loss, frequency of intraoperative fluoroscopy, incision length, incidence of postoperative deep vein thrombosis of lower extremity, pain visual analogue scale (VAS) score at 1 week after operation, and Harris score of hip joint at 3 months after operation were recorded and compared. X-ray re-examination was taken to check the quality of fracture reduction, fracture healing, and the shortening length of the femoral neck at 3 months after operation, and the incidences of internal fixation failure and osteonecrosis of the femoral head during operation. Results Compared with the control group, the operation time, intraoperative blood loss, and frequency of intraoperative fluoroscopy reduced in the two plate groups, and the quality of fracture reduction was better, but the incision was longer, and the differences were significant (P<0.05). The operation time and intraoperative blood loss were significantly higher in the traditional plate group than in the mortise-tenon joint plate group (P<0.05), the incision was significantly longer (P<0.05); and the difference in fracture reduction quality and the frequency of intraoperative fluoroscopy was not significant between two plate groups (P>0.05). There was 1 case of deep vein thrombosis of lower extremity in the traditional plate group and 1 case in the control group, while there was no thrombosis in the mortise-tenon joint plate group. There was no significant difference in the incidence between groups (P>0.05). All patients were followed up 12-15 months (mean, 13 months). There was no significant difference in VAS score at 1 week and Harris score at 3 months between groups (P>0.05). Compared with the control group, the fracture healing time and the length of femoral neck shortening at 3 months after operation were significantly shorter in the two plate groups (P<0.05). There was no significant difference between the two plate groups (P>0.05). There was no significant difference in the incidences of non-union fractures, osteonecrosis of the femoral head, or internal fixation failure between groups (P>0.05). Conclusion For Pauwels type Ⅲ femoral neck fractures, the use of 3D printed guide plate assisted reduction and fixation can shorten the fracture healing time, reduce the incidence of postoperative complications, and be more conducive to the early functional exercise of the affected limb. Compared with the traditional guide plate, the mortise-tenon joint plate can reduce the intraoperative bleeding and shorten the operation time.

    Release date:2025-03-14 09:43 Export PDF Favorites Scan
  • Treatment of posterolateral tibial plateau fractures with a novel lateral tibial plateau annular plate via fibular neck osteotomy approach

    Objective To investigate the effectiveness of a novel lateral tibial plateau annular plate (hereinafter referred to as the novel plate) fixation via fibular neck osteotomy approach for posterolateral tibial plateau fractures. Methods Between January 2015 and December 2018, 22 patients with posterolateral tibial plateau fractures were treated. There were 10 males and 12 females with an average age of 39.0 years (range, 25-56 years). Seven fractures were caused by falls, 10 by traffic accidents, and 5 by falling from height. The time from injury to hospitalization ranged from 3 to 12 days, with an average of 7.0 days. All patients were closed fractures. According to Schatzker classification, the fractures were classified as type Ⅱ in 8 cases, type Ⅲ in 9 cases, type Ⅴ in 1 case, and type Ⅵ in 4 cases. The fractures were fixed with the novel plates after reduction via fibular neck osteotomy approach. The fracture reduction and healing were observed by X-ray film after operation. The range of motion of the knee joint was recorded and the function was evaluated by modified American Hospital for Special Surgery (HSS) score. Results All operations were completed successfully. The operation time was 60-95 minutes (mean, 77.6 minutes). The intraoperative blood loss was 100-520 mL (mean, 214.5 mL). There was 1 case of common peroneal nerve injury during operation and 2 cases of fat liquefaction of incision after operation. All patients were followed up 13-32 months (mean, 19.4 months). Postoperative X-ray films showed that the fracture reduction was good in 17 cases and moderate in 5 cases, and all fractures healed with a healing time of 10-18 weeks (mean, 13.0 weeks). At last follow-up, the range of motion of the knee joint ranged from 100° to 145° in flexion (mean, 125.5°) and from 0° to 4° in extension (mean, 1.2°). The modified HSS score was 82-95 (mean, 86.3). There was no complications such as plate deformation, screw fracture, fracture reduction loss, skin necrosis, and so on. Conclusion For posterolateral tibial plateau fractures, the novel plate fixation via fibular neck osteotomy approach has the advantages of clear intraoperative field, firm fracture fixation, and less postoperative complications, which is beneficial to the recovery of knee joint function.

    Release date:2022-09-30 09:59 Export PDF Favorites Scan
  • Effectiveness of new Pilon plate in treatment of type C Pilon fracture

    Objective By comparing with traditional L-shaped plate, to explore the effectiveness of new Pilon plate in the treatment of type C Pilon fracture.Methods A clinical data of 57 patients with type C Pilon fractures who met the selection criteria between May 2018 and January 2020 was analyzed retrospectively. Thirty-two patients were treated with new Pilon plate (trial group) and 25 patients with traditional L-shaped plate (control group). There was no significant difference in gender, age, cause of injury, fracture side and type, the interval between injury and operation between the two groups (P>0.05). The operation time and complications of the two groups were recorded. X-ray films were taken after operation to assess the quality of fracture reduction according to the Burwell-Charnley classification and fracture healing. Ankle function was evaluated according to Johner-Wruhs scoring standard and American Orthopaedic Foot and Ankle Society (AOFAS) score.Results The operations of the two groups were completed successfully, and the operation time of the trial group was significantly shorter than that of the control group (t=–3.025, P=0.005). After operation, the incision necrosis occurred in 2 cases of the control group, and the incisions of other patients in both groups healed by first intention. All patients were followed up 8-16 months, with an average of 10.1 months. There was no significant difference in follow-up time between the two groups (t=0.433, P=0.667). X-ray films showed that the ankle reduction of the trial group was rated as excellent in 28 cases and good in 4 cases, with an excellent and good rate of 100%, while in the control group, the ankle reduction was rated as excellent in 15 cases, good in 5 cases, and fair in 5 cases, with an excellent and good rate of 80.0%. There was a significant difference in the excellent and good rate of fracture reduction between the two groups (Z=–2.565, P=0.010). The fracture healed in both groups, and the healing time was (16.59±3.78) weeks in the trial group and (17.80±3.81) weeks in the control group, and there was no significant difference between the two groups (t=–1.191, P=0.239). At last follow-up, according to Johner-Wruhs scoring standard, the ankle joint function in the trial group was evaluated as excellent in 25 cases and good in 7 cases, with an excellent and good rate of 100%; the AOFAS score was 90.9±4.5. In the control group, 16 cases were excellent, 5 cases were good, and 4 cases were fair, and the excellent and good rate was 84.0%; the AOFAS score was 85.2±10.0. The ankle function scores of the trial group was superior to that of the control group (P<0.05). During follow-up, except for 1 case of ankle traumatic arthritis in the control group, there was no complication such as ankle malunion, plate loosening and fracture, or fracture reduction loss in both groups.Conclusion Compared with the traditional L-shaped plate, the new Pilon plate in the treatment of type C Pilon fracture has the advantages of high reduction quality, reliable fixation, less irritation to soft tissue, high fracture healing rate, and satisfactory functional recovery of ankle joint.

    Release date:2023-02-13 09:57 Export PDF Favorites Scan
  • Treatment of Day type Ⅱ pelvic crescent fracture by using percutaneous cannulated screw fixation technique

    ObjectiveTo evaluate the feasibility and effectiveness of percutaneous cannulated screw fixation for the treatment of Day type Ⅱ pelvic crescent fracture.MethodsThe clinical data of 14 patients with Day type Ⅱ pelvic crescent fractures underwent closed reduction and percutaneous cannulated screw fixation between January 2009 and July 2016 were retrospectively analysed. There were 9 males and 5 females, aged 17-65 years (mean, 38 years). The causes of injury included traffic accident in 8 cases, falling from height in 3 cases, bruise injury in 3 cases; all were closed fractures. According to Tile classification, there were 8 cases of type B, 6 cases of type C. There were 13 cases combined with fracture of the anterior pelvic ring, including 8 cases of superior and inferior ramus of pubis fracture, 1 case of superior ramus of pubis fracture with symphysis separation, and 4 cases of symphysis separation. The interval of injury and admission was 1- 72 hours (mean, 16 hours), and the interval of injury and operation was 3-8 days (mean, 5 days). After operation, the reduction of fracture was evaluated by the Matta evaluation criteria, the clinical function was assessed by Majeed function assessment.ResultsThe operation time was 35-95 minutes (mean, 55 minutes), cumulative C-arm fluoroscopy time was 3-8 minutes (mean, 5 minutes), no iatrogenic vascular injury and pelvic organ damage occurred. Postoperative X-ray films at 2 days indicated that 2 cases of vertical shift and 2 cases of mild rotation were not completely corrected. Postoperative CT examination at 3 days indicated that 2 pubic joint screws broke through the obturator bone cortex. None of the pubic ramus screws entered into the acetabulum, but a screw of superior pubic branch broke through the posterior cortical of superior pubic branch, a screw of posterior ilium column broke through the medial bone cortex of the ilium, and no clinical symptom was observed. One patient suffered from wound infection in the pubic symphysis, then healed after 2 weeks of wound drainage, the other wounds healed by first intention. According to Matta criterion for fracture reduction, the results were excellent in 9 cases, good in 4 cases, and fair in 1 case with an excellent and good rate of 92.9%. All patients were followed up 8-24 months (mean, 14 months). All fractures healed at 4 months and restored to the normal walking at 6 months after operation, 3 patients suffered from slight pain in the sacroiliac joints and slight claudication when they were tired or walked for a long time and unnecessary for special treatment. One patient felt pain in the back of the iliac spine when he was lying down. During the follow-up, no screw loosening or other internal fixation failure occurred. At last follow-up, according to Majeed functional evaluation criteria, the results were excellent in 7 cases, good in 5 cases, and fair in 2 cases with an excellent and good rate of 85.7%.ConclusionThe percutaneous cannulated screw fixation is a safe treatment for Day type Ⅱ pelvic crescent fracture, which has a reliable fixation and good effectiveness.

    Release date:2018-02-07 03:21 Export PDF Favorites Scan
  • The effect of the sequence of intermediate instrumentation and distraction-reduction of the fractured vertebrae on the surgical treatment of mild to moderate thoracolumbar burst fractures

    Objective To investigate the effect of the sequence of intermediate instrumentation with long screws and distraction-reduction on mild to moderate thoracolumbar fractures treated by posterior open and short-segmental fixation. MethodsThe clinical data of 68 patients with mild to moderate thoracolumbar burst fractures who met the selection criteria between January 2016 and June 2019 were retrospectively analyzed. The patients were divided into group ISDRF (intermediate screws then distraction-reduction fixation, 32 cases) and group DRISF (distraction-reduction then intermediate screws fixation, 36 cases) according to the different operation methods. There was no significant difference between the two groups in age, gender, body mass index, fracture segment, cause of injury, and preoperative load-sharing classification score, thoracolumbar injury classification and severity score, vertebral canal occupational rate, back pain visual analogue scale (VAS) score, anterior height of fractured vertebra, and Cobb angle (P>0.05). The operation time, intraoperative blood loss, complications, and fracture healing time were recorded and compared between the two groups. The vertebral canal occupational rate, anterior height of fractured vertebra, kyphosis Cobb angle, and back pain VAS score before and after operation were used to evaluate the effectiveness. Results There was no significant difference in intraoperative blood loss and operation time between the two groups (P>0.05). No vascular or spinal nerve injury and deep infections or skin infections occurred in both groups. At 1 week after operation, the vertebral canal occupational rate in the two groups was significantly improved when compared with that before operation (P<0.05), no significant difference was found in the difference of vertebral canal occupational rate before and after operation and improvement between the two groups (P>0.05). The patients in both groups were followed up 18-24 months, with an average of 22.3 months. All vertebral fractures reached bone union at 6 months postoperatively. At last follow-up, there was no internal fixation failures such as broken screws, broken rods or loose screws, but there were 2 cases of mild back pain in the ISDRF group. The intra-group comparison showed that the back pain VAS score, the anterior height of fractured vertebra, and the Cobb angle of the two groups were significantly improved at each time point postoperatively (P<0.05); the VAS scores at 12 months postoperatively and last follow-up were also improved when compared with that at 1 week postoperatively (P<0.05). At last follow-up, the anterior height of fractured vertebra in the ISDRF group was significantly lost when compared with that at 1 week and 12 months postoperatively (P<0.05), the Cobb angle had a significant loss when compared with that at 1 week postoperatively (P<0.05); the anterior height of fractured vertebra and Cobb angle in DRISF group were not significantly lost when compared with that at 1 week and 12 months postoperatively (P>0.05). The comparison between groups showed that there was no significant difference in the remission rate of VAS score between the two groups at 1 week postoperatively (P>0.05), the recovery value of the anterior height of fractured vertebra in ISDRF group was significantly higher than that in DRISF group (P<0.05), the loss rate at last follow-up was also significantly higher (P<0.05); the correction rate of Cobb angle in ISDRF group was significantly higher than that in DRISF group at 1 week postoperatively (P<0.05), but there was no significant difference in the loss rate of Cobb angle between the two groups at last follow-up (P>0.05). ConclusionIn the treatment of mild to moderate thoracolumbar burst fractures with posterior short-segment fixation, the instrumentation of long screws in the injured vertebrae does not affect the reduction of the fracture fragments in the spinal canal. DRISF can better maintain the restored anterior height of the fractured vertebra and reduce the loss of kyphosis Cobb angle during the follow-up, indicating a better long-term effectiveness.

    Release date:2022-06-08 10:32 Export PDF Favorites Scan
  • Clinical study on the subchondral screw compression technique assisted reduction of residual or secondary collapse of lateral tibial plateau

    Objective To explore the reduction and support effect of the subchondral screw compression technique for residual or secondary collapse of the lateral tibial plateau during operation. Methods Between January 2020 and June 2021, 11 patients with residual or secondary collapse of the lateral tibial plateau during operation were treated with the subchondral screw compression technique. There were 6 males and 5 females, aged 52.3 years old (range, 27-64 years). The fractures were caused by traffic accident in 10 cases and falling from height in 1 case and located at the left knee in 6 cases and the right knee in 5 cases. According to Schatzker classification, there were 5 cases of type Ⅱ fractures, 4 cases of type Ⅲ fractures, and 2 cases of type Ⅴfractures. According to the three columns classification, there were 5 cases of lateral column, 4 cases of lateral column and posterior column, and 2 cases of three columns. The time from injury to operation was 4.5 days (range, 3-7 days). During the follow-up, X-ray films were obtained and the Rasmussen standard was used to evaluate the quality of fracture reduction, meanwhile fracture healing was observed. The medial proximal tibial angle (mPTA), posterior tibial slope angle (pTSA), and articular surface collapse were measured at immediate and 12 months after operation. The knee joint range of motion was evaluated at last follow-up, and the knee joint function was evaluated using the Hospital for Special Surgery (HSS) score. Results All operations were successfully completed, with a mean operation time of 71.4 minutes (range, 55-120 minutes), and a mean hospital stay of 8.0 days (range, 5-13 days). The incisions all healed by first intention, without complications such as infection, flap necrosis, or vascular and nerve injury. All patients were followed up 16.5 months on average (range, 12-24 months). X-ray films showed that the fracture reduction score was 14-18 (mean, 16.7) according to Rasmussen score criteria; and 5 cases were rated as excellent and 6 as good. All fractures healed clinically with a mean clinical healing time of 14.9 weeks (range, 12-16 weeks), and there was no complications such as plate or screw loosening. At 12 months after operation, the mPTA and pTSA were (87.5±1.7)° and (6.2±3.1)°, respectively; there was no significant difference when compared to the values at immediate after operation [(87.6±1.8)° and (6.5±3.1)°] (P>0.05). The articular surface of the tibial plateaus was effectively supported, and it collapsed again by 0-1.0 mm at 12 months, with an average of 0.4 mm. At last follow-up, the knee joint range of motion was 115°-135° (mean, 126.8°) and the HSS score for knee joint function was 87-98 (mean, 93.9). Five patients underwent secondary operation to remove the internal fixator at 12-18 months after operation.ConclusionThe subchondral screw compression technique is helpful for the reduction of residual or secondary collapse of the lateral tibial plateau during operation, and can provide good support for osteochondral blocks.

    Release date:2023-12-12 05:09 Export PDF Favorites Scan
  • Application of a new universal locking anatomical plate in treatment of tibial plateau posterolateral column fractures

    Objective To investigate the effectiveness of a new tibial plateau posterolateral column universal locking anatomical plate (hereinafter referred to as “new universal locking anatomical plate”) in the treatment of tibial plateau posterolateral column fractures. Methods Between October 2020 and December 2021, 14 patients with tibial plateau posterolateral column fracture were treated with a new universal locking anatomical plate. There were 7 males and 7 females with an average age of 59 years ranging from 29 to 75 years. There were 5 cases on the left side and 9 cases on the right side. The causes of injury included falling from height in 5 cases, traffic accident in 7 cases, and other injuries in 2 cases. The time from injury to operation ranged from 3 to 10 days, with an average of 6 days. According to Schatzker classification, there were 4 cases of type Ⅱ, 8 cases of type Ⅴ, and 2 cases of type Ⅵ. All fractures involved the posterolateral tibial plateau. Three column classification: two columns (anterolateral column+posterior column) in 4 cases, three columns in 10 cases. The operation time, intraoperative blood loss, fracture healing, and complications were recorded. The reduction of tibial plateau fracture was evaluated by Rasmussen radiographic score, and the recovery of knee function was evaluated by Hospital for Special Surgery (HSS) score. Results All 14 cases completed the operation successfully. The operation time was 95-180 minutes, with an average of 154 minutes, and the intraoperative blood loss was 100-480 mL, with an average of 260 mL. All patients were followed up 6-19 months, with an average of 12.5 months. All fractures healed, and the healing time was 15-24 weeks, with an average of 18.7 weeks. During the follow-up, there was 1 case of common peroneal nerve palsy and 1 case of traumatic osteoarthritis. There was no other complication such as vascular injury, incision infection, deep venous thrombosis of lower limbs, heterotopic ossification, bone nonunion, and failure of internal fixation. The reduction of tibial plateau fractures was good immediately after operation, and the Rasmussen radiological score was 10-18, with an average of 15.7; 3 cases were excellent, 10 cases were good, and 1 case was fair, with an excellent and good rate of 92.9%. The scores and grades of HSS at 3 months after operation and at last follow-up significantly improved when compared with those before operation (P<0.05). There was no significant difference between 3 months after operation and last follow-up (P>0.05).Conclusion For the fractures involving the posterolateral column of the tibial plateau, the new universal locking anatomical plate can provide strong fixation, satisfactory postoperative fracture reduction, and good recovery of knee function.

    Release date:2022-12-19 09:37 Export PDF Favorites Scan
  • Risk of micro-fracture in femoral head after removal of cannulated screws for femoral neck fracture

    ObjectiveTo explore the changes of bone and risk of micro-fracture in femoral head after removal of cannulated screws following femoral neck fracture healing under the impact force of daily stress.MethodsA total of 42 specimens of normal hip joint were collected from 21 adult fresh cadaveric pelvic specimens. Wiberg central-edge (CE) angle, bone mineral density, diameter of femoral head, neck-shaft angle, and anteversion angle of femoral neck were measured. Then, the 3 cannulated screws were implanted according to the AO recommended method and removed to simulate the complete anatomical union of femoral neck fracture. The morphology of screw canal in the femoral head was observed by CT. Finally, the specimens were immobilized vertically within the impact device in an upside-down manner, and the femoral heads were impacted vertically. Every specimen was impacted at 200, 600, and 1 980 N for 20 times with the impacting device. After impact, every specimen was scanned by CT to observe the morphology changes of screw canal in the femoral head. Micro-fractures in the femoral head could be confirmed when there was change in the morphology of screw canal, and statistical software was used to analyze the risk factors associated with micro-fractures.ResultsAfter impact at 200 and 600 N, CT showed that the morphology of screw canal of all specimens did not change significantly compared with the original. After impact at 1 980 N, there were protrusion and narrowing in the screw canal of the 22 femoral head specimens (11 pelvic specimens), showing obvious changes compared with the original screw canal, indicating that there were micro-fractures in the femoral head. The incidence of micro-fracture was 52.38% (11/21). logistic regression results showed that there was correlation between micro-fracture and bone mineral density (P= 0.039), but no correlation was found with CE angle, diameter of femoral head, neck-shaft angle, and anteversion angle (P>0.05).ConclusionThe micro-fractures in the femoral head may occur when the femoral head is impacted by daily activities after removal of cannulated screws for femoral neck fractures, and such micro-fractures are associated with decreased bone density of the femoral head.

    Release date:2020-09-28 02:45 Export PDF Favorites Scan
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