Objective:To evaluate the clinical efficacy of the operation treated of unilateral unstable sacral fracture with S 1 dysplasia by bi-perforative screws of the middle and posterior pelvic columns. Methods:A retrospective analysis was conducted on 18 patients with proximal S 1 dysplasia and unilateral unstable sacral fractures treated at Tianjin Hospital, from January 2018 to January 2023. The cohort included 10 males and 8 females, with an average age of 46.3±1.2 years (range, 18-56 years). The causes of injury were traffic accidents in 12 cases and falls in 6 cases. All patients had combined anterior pelvic ring injuries, including 14 cases of simple fractures and 4 cases of fractures combined with pubic symphysis injuries. Preoperative neuro-magnetic resonance imaging (MRI) confirmed that the lumbosacral nerves were not compressed by fracture fragments or displaced bone ends. According to the Dennis classification, there were 8 cases of type I and 10 cases of type II sacral fractures. Abnormalities in S 1 development included 9 cases of steep slopes, 6 cases of anterior rim depression, and 3 cases of both deformities simultaneously. There were 2 cases of nerve injury, both of which were Gibbons grade II. The average time from injury to surgery was 5.4±1.7 days (range, 4-14 days). All patients underwent combined anterior and posterior pelvic fixation in a single stage, with sacral fractures fixed using bi-perforative screws of posterior pelvic ring. The following parameters were recorded: screw placement time, intraoperative blood loss, fluoroscopy time, fracture healing time, accuracy of internal fixation placement, postoperative infection rate, and iatrogenic injury incidence. The Mears scoring system was used to evaluate the satisfaction rate of sacral fracture reduction, the Gibbons classification was used to assess neurological recovery, and the Majeed score was used to evaluate pelvic function. Results:The average screw placement time was 38.7±3.5 min for S 1 and 16.5±1.3 min for the posterior column. The average blood loss during screw placement was 30.53±1.61 ml, and the average fluoroscopy time was 11.3±3.2 s. No vascular or nerve injuries occurred in any case after the operation. All sacral fractures healed, with an average healing time of 7.6±2.2 months (range, 3-12 months). No cases of fracture re-displacement or internal fixation failure were observed. The Mears evaluation results showed anatomical reduction in 12 cases, satisfactory reduction in 4 cases, and unsatisfactory reduction in 2 cases. All internal fixations were accurately placed. All 18 patients were followed up with an average of 18.2±2.5 months (range, 12-36 months). At the last follow-up, the average Majeed score was 87.4±2.9, with 11 cases rated as excellent, 4 as good, and 3 as fair. The two patients with Gibbons grade II nerve injuries improved to grade I postoperatively. Conclusion:Bi-perforative screws fixation for the middle and posterior pelvic columns offers several advantages, including straightforward operation, precise minimally invasive placement, safety and efficacy, robust fixation, and low complication rates, resulting in satisfactory clinical outcomes.

Objective:To evaluate the value of intraoperative cone beam CT (CBCT) in robot-assisted iliosacral screw fixation for posterior pelvic ring injuries.Methods:The 70 patients' data with posterior pelvic ring injuries treated in Tianjin Hospital from March 2020 to October 2023 were retrospectively analyzed. According to the operation method and whether there was intraoperative CBCT verification, the patients were divided into the robot-assisted iliosacral screw fixation group verified by CBCT with 15 cases (robot+CT group), the simple robot-assisted iliosacral screw fixation group with 25 cases (robot group), the freehand iliosacral screw fixation group verified by CBCT with 10 cases (freehand+CT group), and the freehand iliosacral screw fixation group with 20 cases (freehand group). The operation time, the number of intraoperative fluoroscopies, the frequency of guide needle adjustment of each iliosacral screw, Majeed function score, Matta score, fracture healing time, Gras classification of screw position of the four groups were compared, and the iliosacral screw's perforation site were recorded.Results:All patients were followed up, and the follow-up time was 18.89±4.13 months (range, 12-30 months). There were no statistically significant differences in postoperative fracture Matta score, Majeed score and fracture healing time among the four groups ( P>0.05). Specifically, 26, 45, 15, and 32 iliacsacral screws were inserted in the robot+CT group, the robot group, the freehand+CT group, and the freehand group, respectively. The operation times for these groups were 20.19±1.24, 18.78±1.00, 38.13±2.32, and 37.56±1.80 min, respectively. The number of intraoperative fluoroscopies per screw were 20.50±1.37, 18.47±1.06, 39.80±3.56, and 39.34±1.93, respectively. The guide needle adjustment times were 0.54±0.15, 0.47±0.10, 9.33±1.34, and 8.56±0.86, respectively. Statistically significant differences were observed in the above three indicators among the four groups ( P<0.05). There was no statistically significant difference in Gras classification of screw positions among the four groups ( P>0.05). However, in the CBCT verification group (robot+CT group and freehand+CT group), the Gras classification results were 36 screws in Grade I, 4 in Grade II, 1 in Grade III, and 0 in Grade IV. In contrast, in the non-CBCT verification group (robot group and freehand group), there were 48 screws in Grade I, 17 in Grade II, 11 in Grade III, and 1 in Grade IV, with a statistically significant difference (χ 2=8.945, P=0.030). The screw perforation rate in the CBCT verification group was 2% (1/41), with no perforation observed in the robot+CT verification group, compared to 16% (12/77) in the non-CBCT verification group, showing a statistically significant difference (χ 2=4.716, P=0.030). Among the 13 perforating iliosacral screws, two were located in the anterior slope of the sacrum, while 11 were positioned in the posterior and inferior dangerous triangle area of the sacral vertebral body, and the screws were penetrated into the sacral nerve root channel. Conclusions:Robot-assisted iliosacral screw with short operation time, less fluoroscopies and less guide needle adjustments, the screws can be accurately placed according to the plan, with satisfactory clinical outcomes. The penetration sites of robot-assisted iliosacral screw based on two-dimensional X-ray planning were mostly located in the posterior and inferior of the vertebral body at the pedicle level. Intraoperative CBCT can significantly improve the accuracy of sacroiliac screw placement.

A case of traumatic complete lumbosacral spondylolisthesis combined with unstable pelvic fracture is reported. A 55-year-old male patient was admitted to the hospital 8 h after being hit by a heavy object on the lumbosacral region. Admission diagnosis: (1) traumatic hemorrhagic shock; (2) bilateral pulmonary contusion with pleural effusion, and dislocation of the right 12th costovertebral joint; (3) left renal contusion with subcapsular hematoma; (4) traumatic lumbosacral spondylolisthesis (Meyerding grade V), L 5 lamina fracture, L 2 and L 5 spinous process fractures, left L 3-L 5 transverse process fractures, right L 5 inferior articular process fracture, and L 1-L 3 and L 5 transverse process fractures; (5) lumbosacral Morel-Lavallée lesion; (6) pubic symphysis separation, left sacral wing fracture, and sacroiliac joint dislocation (Young-Burgess APC type III); (7) Multiple incomplete injuries of bilateral lumbosacral nerves, and cauda equina syndrome (Gibbons type Ⅳ). The patient underwent open reduction of pelvic fracture and pubic symphysis separation, closed reduction of sacroiliac joint dislocation and combined internal and external fixation, and open reduction and internal fixation of lumbosacral spondylolisthesis. At the 1-year follow-up after surgery, the pelvis achieved anatomical reduction with good fracture healing, the spinal anatomical alignment returned to normal, and lumbosacral bony fusion was observed, and weakness of both lower limbs and abnormal urodynamics caused by residual lumbosacral nerve injury were observed.

Objective:To evaluate the clinical efficacy of the operation treated of unilateral unstable sacral fracture with S 1 dysplasia by bi-perforative screws of the middle and posterior pelvic columns. Methods:A retrospective analysis was conducted on 18 patients with proximal S 1 dysplasia and unilateral unstable sacral fractures treated at Tianjin Hospital, from January 2018 to January 2023. The cohort included 10 males and 8 females, with an average age of 46.3±1.2 years (range, 18-56 years). The causes of injury were traffic accidents in 12 cases and falls in 6 cases. All patients had combined anterior pelvic ring injuries, including 14 cases of simple fractures and 4 cases of fractures combined with pubic symphysis injuries. Preoperative neuro-magnetic resonance imaging (MRI) confirmed that the lumbosacral nerves were not compressed by fracture fragments or displaced bone ends. According to the Dennis classification, there were 8 cases of type I and 10 cases of type II sacral fractures. Abnormalities in S 1 development included 9 cases of steep slopes, 6 cases of anterior rim depression, and 3 cases of both deformities simultaneously. There were 2 cases of nerve injury, both of which were Gibbons grade II. The average time from injury to surgery was 5.4±1.7 days (range, 4-14 days). All patients underwent combined anterior and posterior pelvic fixation in a single stage, with sacral fractures fixed using bi-perforative screws of posterior pelvic ring. The following parameters were recorded: screw placement time, intraoperative blood loss, fluoroscopy time, fracture healing time, accuracy of internal fixation placement, postoperative infection rate, and iatrogenic injury incidence. The Mears scoring system was used to evaluate the satisfaction rate of sacral fracture reduction, the Gibbons classification was used to assess neurological recovery, and the Majeed score was used to evaluate pelvic function. Results:The average screw placement time was 38.7±3.5 min for S 1 and 16.5±1.3 min for the posterior column. The average blood loss during screw placement was 30.53±1.61 ml, and the average fluoroscopy time was 11.3±3.2 s. No vascular or nerve injuries occurred in any case after the operation. All sacral fractures healed, with an average healing time of 7.6±2.2 months (range, 3-12 months). No cases of fracture re-displacement or internal fixation failure were observed. The Mears evaluation results showed anatomical reduction in 12 cases, satisfactory reduction in 4 cases, and unsatisfactory reduction in 2 cases. All internal fixations were accurately placed. All 18 patients were followed up with an average of 18.2±2.5 months (range, 12-36 months). At the last follow-up, the average Majeed score was 87.4±2.9, with 11 cases rated as excellent, 4 as good, and 3 as fair. The two patients with Gibbons grade II nerve injuries improved to grade I postoperatively. Conclusion:Bi-perforative screws fixation for the middle and posterior pelvic columns offers several advantages, including straightforward operation, precise minimally invasive placement, safety and efficacy, robust fixation, and low complication rates, resulting in satisfactory clinical outcomes.

Objective:To evaluate the value of intraoperative cone beam CT (CBCT) in robot-assisted iliosacral screw fixation for posterior pelvic ring injuries.Methods:The 70 patients' data with posterior pelvic ring injuries treated in Tianjin Hospital from March 2020 to October 2023 were retrospectively analyzed. According to the operation method and whether there was intraoperative CBCT verification, the patients were divided into the robot-assisted iliosacral screw fixation group verified by CBCT with 15 cases (robot+CT group), the simple robot-assisted iliosacral screw fixation group with 25 cases (robot group), the freehand iliosacral screw fixation group verified by CBCT with 10 cases (freehand+CT group), and the freehand iliosacral screw fixation group with 20 cases (freehand group). The operation time, the number of intraoperative fluoroscopies, the frequency of guide needle adjustment of each iliosacral screw, Majeed function score, Matta score, fracture healing time, Gras classification of screw position of the four groups were compared, and the iliosacral screw's perforation site were recorded.Results:All patients were followed up, and the follow-up time was 18.89±4.13 months (range, 12-30 months). There were no statistically significant differences in postoperative fracture Matta score, Majeed score and fracture healing time among the four groups ( P>0.05). Specifically, 26, 45, 15, and 32 iliacsacral screws were inserted in the robot+CT group, the robot group, the freehand+CT group, and the freehand group, respectively. The operation times for these groups were 20.19±1.24, 18.78±1.00, 38.13±2.32, and 37.56±1.80 min, respectively. The number of intraoperative fluoroscopies per screw were 20.50±1.37, 18.47±1.06, 39.80±3.56, and 39.34±1.93, respectively. The guide needle adjustment times were 0.54±0.15, 0.47±0.10, 9.33±1.34, and 8.56±0.86, respectively. Statistically significant differences were observed in the above three indicators among the four groups ( P<0.05). There was no statistically significant difference in Gras classification of screw positions among the four groups ( P>0.05). However, in the CBCT verification group (robot+CT group and freehand+CT group), the Gras classification results were 36 screws in Grade I, 4 in Grade II, 1 in Grade III, and 0 in Grade IV. In contrast, in the non-CBCT verification group (robot group and freehand group), there were 48 screws in Grade I, 17 in Grade II, 11 in Grade III, and 1 in Grade IV, with a statistically significant difference (χ 2=8.945, P=0.030). The screw perforation rate in the CBCT verification group was 2% (1/41), with no perforation observed in the robot+CT verification group, compared to 16% (12/77) in the non-CBCT verification group, showing a statistically significant difference (χ 2=4.716, P=0.030). Among the 13 perforating iliosacral screws, two were located in the anterior slope of the sacrum, while 11 were positioned in the posterior and inferior dangerous triangle area of the sacral vertebral body, and the screws were penetrated into the sacral nerve root channel. Conclusions:Robot-assisted iliosacral screw with short operation time, less fluoroscopies and less guide needle adjustments, the screws can be accurately placed according to the plan, with satisfactory clinical outcomes. The penetration sites of robot-assisted iliosacral screw based on two-dimensional X-ray planning were mostly located in the posterior and inferior of the vertebral body at the pedicle level. Intraoperative CBCT can significantly improve the accuracy of sacroiliac screw placement.

A case of traumatic complete lumbosacral spondylolisthesis combined with unstable pelvic fracture is reported. A 55-year-old male patient was admitted to the hospital 8 h after being hit by a heavy object on the lumbosacral region. Admission diagnosis: (1) traumatic hemorrhagic shock; (2) bilateral pulmonary contusion with pleural effusion, and dislocation of the right 12th costovertebral joint; (3) left renal contusion with subcapsular hematoma; (4) traumatic lumbosacral spondylolisthesis (Meyerding grade V), L 5 lamina fracture, L 2 and L 5 spinous process fractures, left L 3-L 5 transverse process fractures, right L 5 inferior articular process fracture, and L 1-L 3 and L 5 transverse process fractures; (5) lumbosacral Morel-Lavallée lesion; (6) pubic symphysis separation, left sacral wing fracture, and sacroiliac joint dislocation (Young-Burgess APC type III); (7) Multiple incomplete injuries of bilateral lumbosacral nerves, and cauda equina syndrome (Gibbons type Ⅳ). The patient underwent open reduction of pelvic fracture and pubic symphysis separation, closed reduction of sacroiliac joint dislocation and combined internal and external fixation, and open reduction and internal fixation of lumbosacral spondylolisthesis. At the 1-year follow-up after surgery, the pelvis achieved anatomical reduction with good fracture healing, the spinal anatomical alignment returned to normal, and lumbosacral bony fusion was observed, and weakness of both lower limbs and abnormal urodynamics caused by residual lumbosacral nerve injury were observed.

Objective:To compare the efficacy of the horizontal plate plus raft screws above the acetabulum and fixation with screws only for acetabular fractures combined with dome impaction in the aged patients.Methods:A retrospective cohort study was conducted to analyze the clinical data of 20 aged patients with acetabular fractures combined with dome impaction, who were admitted to Tianjin hospital between May 2013 and January 2023, including 5 males and 15 females, aged 61-84 years [(72.2±7.3)years]. According to Letournel and Judet classification, 13 patients had anterior column fracture, 5 anterior column fracture combined with posterior transverse fracture and 2 two-column fracture. All the patients underwent open reduction and internal fixation through an anterior approach. Of them, 11 patients were treated with the fixation with the horizonal plate plus raft screws above the acetabulum (plate plus raft screw group) and 9 with the screws only (screw only group). The operative time, intraoperative blood loss, and intraoperative fluoroscopy times were compared between the two groups. The quality of fracture reduction was evaluated with the Matta′s radiographic criteria at 3 days after surgery and the function of the hip joint was assessed with Merle D′Aubigné and Postel scoring system at 3 months after surgery and at the last follow-up as well as the excellent and good rate at te last follow-up. The occurrence of postoperative complications was observed.Results:All the patients were followed up for 6-18 months [(13.1±3.1)months]. There were no significant differences in the operative time, intraoperative blood loss or intraoperative fluoroscopy times between the two groups ( P>0.05). According to the Matta′s radiographic criteria at 3 days after surgery, patients with anatomical reduction and satisfactory reduction accounted 6 and 5 in the plate plus raft screw group, compared to 5 and 4 respectively in the screw only group ( P>0.05). The values of Merle D′Aubigné and Postel score at 3 months after surgery and at the last follow-up were (14.0±2.4)points and (15.8±2.2)points in the plate plus raft screw group, which were higher than those in the screw only group [(11.0±2.6)points and (13.0±3.1)points] ( P<0.01). The values of Merle D′Aubigné and Postel score at the last follow-up of both groups were further enhanced from those at 3 months after surgery ( P<0.01). At the last follow-up, 3 patients were rated excellent, 6 good, 1 fair and 1 poor in the plate plus raft screw group, with an excellent and good rate of 81.8%, while in the screw only group, 3 were rated good, 2 fair and 4 poor, with an excellent and good rate of 33.3% ( P<0.05). One patient in the plate plus raft screw group and 5 in the screw only group had displacement of the dome impaction fragment combined with traumatic arthritis after surgery ( P<0.05). Conclusion:For acetabular fractures combined with dome impaction in the aged patients, the horizontal plate plus raft screw above the acetabulum can effectively improve the function restoration of the hip joint and reduce the occurrence of the displacement of the dome impaction fragment and traumatic arthritis after surgery compared to the fixation with screws only.

Closed reduction percutaneous screw fixation offers significant biological and biomechanical advantages and can be employed independently for the surgical treatment of pelvic acetabular fractures, as well as serving as a complementary method to open reduction internal fixation. The osseous fixation pathway (OFP) constitutes the anatomical foundation for the minimally invasive approach to pelvic and acetabular fracture management. The pelvis's OFP can be categorized into anterior, middle, and posterior parts. The anterior OFP encompasses both the superior pubic/anterior column and inferior pubic OFPs. The former is primarily utilized for addressing transverse and T-shaped acetabular fractures, as well as anterior column and superior pubic fractures. The latter is predominantly applied to inferior pubic fractures. The middle OFP includes the anterior inferior iliac spine to the posterior iliac crest (LC-II) OFP, the gluteus medius column OFP, and the iliac crest OFP. The LC-II OFP is primarily designated for pelvic crescent, iliac wing, and select high anterior column acetabular fractures. The gluteus medius column OFP is used for the treatment of some iliac fractures or acetabular fractures. And the iliac crest OFP is used for the treatment of simple iliac wing fractures or acetabular fractures involving the iliac crest. The posterior OFP includes the posterior column of the acetabulum OFP, sacroiliac OFP, and sacral OFP. The posterior column of the acetabulum OFP is used for the treatment of acetabular fractures involving the posterior column; the sacroiliac OFP is mainly utilized for a range of pelvic injuries, including pelvic rotational or vertical unstable pelvic injury, sacroiliac dislocation or fracture dislocation; open injury of the posterior ring of the pelvis with relatively mild contamination; elderly sacral (incomplete) fractures; residual gap at the end of sacral fracture after pubic symphysis and plate internal fixation; certain traumatic spinopelvic dissociation ; in combination with lumbopelvic fixation for the treatment of pelvic fractures with lumbosacral junction injury. Sacral OFP is advised for treating bilateral sacroiliac dislocation and certain crescent-like pelvic fractures; bilateral sacral fractures; sacral fractures involving Denis III zone, osteoporotic sacral incomplete fractures. The pursuit of minimally invasive treatment modalities for pelvic and acetabular fractures comes with challenges. A comprehensive understanding of OFP morphology and intraoperative imaging, coupled with a commitment to enhancing fracture reduction quality and surgical proficiency, is imperative for the precise management of such injuries.

The surgical reduction and fixation of subtrochanteric femoral fractures are challenging due to its particular anatomical and biomechanical characteristics. Intramedullary nailing is the golden standard for its treatment, but postoperative bone nonunion is a common complication, resulting in limb pain and decreased mobility, which requires a second operation and greatly affects the patients′ life quality. At present, there are many studies on the risk factors of bone nonunion after intramedullary nail fixation, but the risk factors with strong correlation remain unclear and the subsequent treatment plans are diverse, without consensus. Further identification of risk factors can help to select treatment plans. To this end, the authors reviewed the research progress in the risk factors and treatment methods of bone nonunion after intramedullary nailing of subtrochanteric femoral fractures to provide references for its clinical treatment.

Periprosthetic fracture of femur is the most common postoperative complication after total knee arthroplasty (TKA). Risk factors for periprosthetic fractures include female sex, osteoporosis/osteopenia, rheumatoid arthritis, osteoarthritis, neuromuscular disease, cognitive disorder, chronic use of corticosteroids, obesity, advanced age, infection, osteolysis around the prosthesis, knee joint ankyloses, notching of the anterior femoral cortex, etc. According to epidemiological research, the incidence of femoral periprosthetic fractures following TKA ranges from 0.3% to 2.5%. Lewis and Rorabeck classifications, the most commonly used classification of periprosthetic fractures of the femur, introduce the concept of prosthesis loosening and emphasize the ecessity of revision surgery. Other classifications include Su typing, Universal Typing System, and Rhee typing, the latest of which is the Kim typing proposed in 2022. Treatment strategies for periprosthetic femoral fractures after TKA include nonsurgical treatment, external fixation techniques, single-plate fixation, double-plate fixation, intramedullary nail fixation, and revision TKA and distal femur replacement. The purpose of this paper is to better guide the prevention and treatment of periprosthetic fractures after TKA by searching and analyzing relevant literature on periprosthetic fractures after TKA.