Objective:To assess the clinical outcomes of dual-approach bicondylar fixation under adjustable positioning for Schatzker type IV trans-midline tibial plateau fractures.Methods:A retrospective cohort study was conducted to analyze the clinical data of 52 patients with Schatzker type IV trans-midline tibial plateau fractures admitted to First Affiliated Hospital to Nanjing Medical University from January 2014 to August 2023, including 37 males and 15 females, aged 19-68 years [(42.3±14.0)years]. All the patients were treated with the surgical scheme of anterior and medial dual-approach bicondylar internal fixation under adjustable positioning. The operation duration, intraoperative blood loss, and fracture healing time were counted. X-ray films were reviewed at 2 days after surgery for residual knee subluxation. At 2 days, 3 and 6 months after surgery, and at the last follow-up, the tibial plateau angle (TPA) and posterior slope angle (PA) were measured with follow-up X-ray films to evaluate whether there was loss of reduction. The knee function was evaluated with the American Hospital for Special Surgery (HSS) knee function score at 3 and 6 months after surgery and at the last follow-up. The anterior posterior displacement and rotation stability of the knee were evaluated with Lachman test and pivot-shift test at the last follow-up. The postoperative complications were recorded.Results:All the patients were followed up for 12-118 months [70(46, 85)months]. The operation duration was 100-180 minutes [145(120, 160)minutes], with intraoperative blood loss of 100-550 ml [(323.8±135.1)ml]. Fractures were healed well in all the patients, with the healing time of 2-4 months [3.0(2.4, 3.5)months]. None of the patients had residual subluxation by X-ray films at 2 days after surgery. There were no significant differences in TPA or PA at each time point after surgery ( P>0.05). The HSS knee function score was (69.4±4.9)points, (80.9±7.0)points, and (90.1±7.9)points at 3 and 6 months after surgery and at the last follow-up, respectively and the score gradually increased with the passage of time ( P<0.05). At the last follow-up, all the patients were negative in Lachman test and pivot-shift test. Three patients developed fat liquefaction around medial wounds after surgery, which were healed after dressing change. While the wounds were healed by first intention in the other patients. Postoperative complications such as knee instability, implant loosening, fracture or refracture not occurred. Conclusion:Dual-approach bicondylar fixation under adjustable positioning for Schatzker type IV trans-midline tibial plateau fractures has the advantages including high fracture healing rate, precise fracture reduction and fixation, satisfactory postoperative functional recovery and fewer complications, without increasing operation duration or intraoperative blood loss.

Objective:To assess the clinical outcomes of dual-approach bicondylar fixation under adjustable positioning for Schatzker type IV trans-midline tibial plateau fractures.Methods:A retrospective cohort study was conducted to analyze the clinical data of 52 patients with Schatzker type IV trans-midline tibial plateau fractures admitted to First Affiliated Hospital to Nanjing Medical University from January 2014 to August 2023, including 37 males and 15 females, aged 19-68 years [(42.3±14.0)years]. All the patients were treated with the surgical scheme of anterior and medial dual-approach bicondylar internal fixation under adjustable positioning. The operation duration, intraoperative blood loss, and fracture healing time were counted. X-ray films were reviewed at 2 days after surgery for residual knee subluxation. At 2 days, 3 and 6 months after surgery, and at the last follow-up, the tibial plateau angle (TPA) and posterior slope angle (PA) were measured with follow-up X-ray films to evaluate whether there was loss of reduction. The knee function was evaluated with the American Hospital for Special Surgery (HSS) knee function score at 3 and 6 months after surgery and at the last follow-up. The anterior posterior displacement and rotation stability of the knee were evaluated with Lachman test and pivot-shift test at the last follow-up. The postoperative complications were recorded.Results:All the patients were followed up for 12-118 months [70(46, 85)months]. The operation duration was 100-180 minutes [145(120, 160)minutes], with intraoperative blood loss of 100-550 ml [(323.8±135.1)ml]. Fractures were healed well in all the patients, with the healing time of 2-4 months [3.0(2.4, 3.5)months]. None of the patients had residual subluxation by X-ray films at 2 days after surgery. There were no significant differences in TPA or PA at each time point after surgery ( P>0.05). The HSS knee function score was (69.4±4.9)points, (80.9±7.0)points, and (90.1±7.9)points at 3 and 6 months after surgery and at the last follow-up, respectively and the score gradually increased with the passage of time ( P<0.05). At the last follow-up, all the patients were negative in Lachman test and pivot-shift test. Three patients developed fat liquefaction around medial wounds after surgery, which were healed after dressing change. While the wounds were healed by first intention in the other patients. Postoperative complications such as knee instability, implant loosening, fracture or refracture not occurred. Conclusion:Dual-approach bicondylar fixation under adjustable positioning for Schatzker type IV trans-midline tibial plateau fractures has the advantages including high fracture healing rate, precise fracture reduction and fixation, satisfactory postoperative functional recovery and fewer complications, without increasing operation duration or intraoperative blood loss.

Objective:To establish a new classification system for distal clavicle fracture and evaluate its clinical effectiveness.Methods:A retrospective case series study was conducted to analyze the clinical data of 101 patients with distal clavicle fracture admitted to First Affiliated Hospital of Nanjing Medical University from January 2015 to March 2022, including 57 males and 44 females, aged 19-86 years [(53.8±14.0)years]. Before treatment, patients were routinely subjected to bilateral anteroposterior radiography of the shoulder joints to measure the length of the fractured fragments, coracoclavicular distance, and acromioclavicular distance. According to the correlation between the location of the fracture line and the insertion of the coracoclavicular ligament, distal clavicle fracture was divided into three types: type I, with the fracture line lateral to the coracoclavicular ligament region; type II, with the fracture line in the coracoclavicular ligament region; type III, with the fracture line medial to the coracoclavicular ligament region. According to the injury severity of the coracoclavicular ligament and acromioclavicular ligament, type I was further subdivided into type IA, IB, IC and ID, and type II fracture was further subdivided into type IIA, IIB, IIC, IID and IIE. All the 101 patients were classified and randomly reclassified at an interval of 3 months by 10 senior and 10 junior shoulder surgeons according to the new classification method. Kappa coefficients were used to evaluate the inter- and intra-observer consistency of the new classification. Fifty-two patients with stable fracture (types IA, IB, IIC, and IID) were treated non-surgically, while 49 patients with unstable fracture (types IC, ID, IIA, IIB, IIE, and III) were treated surgically, including 26 patients with anatomic coracoclavicular ligament reconstruction, 9 with locking plate fixation, 8 with clavicle hook plate fixation, 4 with anatomic coracoclavicular ligament reconstruction combined with locking plate fixation, and 2 with anatomic coracoclavicular ligament reconstruction combined with tension screw fixation. The patients were assessed using the visual analogue scale (VAS) and Constant-Murley shoulder score before treatment and at 3, 6, 12, and 18 months after treatment. The coracoclavicular distance and acromioclavicular distance on the anteroposterior radiographs of the healthy and affected shoulder joints were measured at 3, 6, 12, and 18 months after treatment, and fracture healing time and complications were observed.Results:The length of the fractured fragments was 12.9 (9.7, 17.6)mm in patients with type I fracture, 24.7 (21.8, 27.8)mm in patients with type II fracture, and 43.6 (41.2, 46.9)mm in patients with type III fracture ( P<0.01). There were no significant differences in the coracoclavicular distance and acromioclavicular distance of the affected and healthy shoulders among the patients with types IA, IB, IIC, IID, and III fracture ( P>0.05); For the patients with types IC, IIA, IIB and IIE fracture, the coracoclavicular distance of the affected shoulder was significantly increased compared with that of the healthy shoulder ( P<0.01), while there was no significant difference in the acromioclavicular distance of the affected and healthy shoulders ( P>0.05). Both of the inter- and intra-observer consistency of the new classification was good. The inter- and intra-observer Kappa values were 0.69 and 0.71 respectively among the senior shoulder surgeons, and 0.61 and 0.64 respectively among the junior shoulder surgeons. All the patients were followed up for 18-104 months [28(23, 32)months]. At 3, 6, 12 and 18 months after treatment, the VAS scores of non-surgical patients were 3(2, 3)points, 2(1, 2)points, 1(0, 1)points and 0(0, 1)points respectively, significantly decreased compared with 6(5, 6)points before treatment ( P<0.01); the VAS scores of surgical patients were 3(2, 3)points, 2(1, 2)points, 1(1, 1)points and 0(0, 1)points respectively, significantly decreased compared with 6(5, 7)points before treatment ( P<0.01); the Constant-Murley shoulder scores of non-surgical patients were (76.6±5.3)points, (84.3±5.0)points, (88.4±4.0)points and (91.9±3.8)points respectively, significantly higher than (42.7±5.2)points before treatment ( P<0.01); the Constant-Murley shoulder scores of surgical patients were (77.4±4.6)points, (84.4±4.7)points, (87.6±3.7)points and (91.7±4.0)points respectively, significantly higher than (42.8±5.3)points before treatment ( P<0.01). At 3, 6, 12 and 18 months after treatment, the coracoclavicular distance of the affected shoulder in non-surgical patients was not significantly different from that before treatment ( P>0.05), while the acromioclavicular distance of the affected shoulder in surgical patients was significantly reduced compared with that before treatment ( P<0.01). There were no significant differences in the coracoclavicular distance of the healthy shoulder or bilateral acromioclavicular distance in non-surgical and surgical patients at 3, 6, 12, and 18 months after treatment compared with those before treatment ( P>0.05). Fractures were healed within 12 months after treatment in all the patients, without dislocation or subluxation of the acromioclavicular joint, internal fixation failure or internal fixator breakage. Eight patients treated with clavicular hook plate fixation had shoulder pain associated with limited mobility after operation, and all underwent a second operation to remove the clavicular hook plate at 12 months after operation. Conclusions:The new classification system for distal clavicle fracture is established, which comprehensively considers the position of the fracture line, injury of the coracoclavicular and acromioclavicular ligaments, and fracture stability. The new classification system exhibits good inter- and intra- observer consistency, and the effectiveness of its preliminary clinical application is satisfactory.

Objective:To evaluate the iliofemoral approach and its modified approaches in the treatment of acetabular fractures involving the roof column and roof wall.Methods:A retrospective study was conducted to analyze the data of 19 patients who had been admitted to Department of Orthopaedics, The First Hospital Affiliated to Nanjing Medical University for acetabular fractures involving the roof column and roof wall from June 2015 to July 2023. There were 12 males and 7 females with an age of (53.5±15.6) years. By the three-column classification for the acetabular fractures, there were 2 cases of type A, 7 cases of type B, and 10 cases of type C. The time from injury to surgery was 6(5, 11) days. All patients underwent surgery through the iliofemoral approach or its modified approaches (the iliofemoral approach in 2 cases, the modified iliofemoral two-window approach in 13 cases, and the modified expanded iliofemoral two-window approach in 4 cases). All patients were fixated with plates and screws after reduction. The surgical time, intraoperative bleeding, complications, quality of fracture reduction, and hip joint function of the affected side were analyzed.Results:For all the 19 patients, the surgical time averaged (186.8±81.3) minutes, and the intraoperative bleeding volume 500(400, 600) mL. After acetabular fracture surgery, anatomical reduction was achieved in 13 cases and satisfactory reduction in 6 cases. The follow-up period for the 19 patients was (42.6±25.9) months. All acetabular fractures achieved bony union after a post-surgery duration of 14(12, 16) weeks. By the modified Merle d'Aubigné & Poster scoring system, the hip function was evaluated at the last follow-up as excellent in 4 cases, as good in 14 cases, and as fair in 1 case. Follow-ups revealed injury to the lateral femoral cutaneous nerve after surgery in 11 patients, of whom 5 were fully recovered and 6 partially recovered after treatment. Ectopic ossification developed after surgery in 3 patients, of whom 1 was rated as Brooker grade Ⅰ and 2 were as Brooker grade Ⅱ.Conclusion:In the treatment of acetabular fractures involving the roof column and roof wall, fixation with plates and screws through the iliofemoral approach or its modified approaches may achieve fine clinical outcomes in addition to the advantages of operative convenience and high safety.

Objective:To evaluate the iliofemoral approach and its modified approaches in the treatment of acetabular fractures involving the roof column and roof wall.Methods:A retrospective study was conducted to analyze the data of 19 patients who had been admitted to Department of Orthopaedics, The First Hospital Affiliated to Nanjing Medical University for acetabular fractures involving the roof column and roof wall from June 2015 to July 2023. There were 12 males and 7 females with an age of (53.5±15.6) years. By the three-column classification for the acetabular fractures, there were 2 cases of type A, 7 cases of type B, and 10 cases of type C. The time from injury to surgery was 6(5, 11) days. All patients underwent surgery through the iliofemoral approach or its modified approaches (the iliofemoral approach in 2 cases, the modified iliofemoral two-window approach in 13 cases, and the modified expanded iliofemoral two-window approach in 4 cases). All patients were fixated with plates and screws after reduction. The surgical time, intraoperative bleeding, complications, quality of fracture reduction, and hip joint function of the affected side were analyzed.Results:For all the 19 patients, the surgical time averaged (186.8±81.3) minutes, and the intraoperative bleeding volume 500(400, 600) mL. After acetabular fracture surgery, anatomical reduction was achieved in 13 cases and satisfactory reduction in 6 cases. The follow-up period for the 19 patients was (42.6±25.9) months. All acetabular fractures achieved bony union after a post-surgery duration of 14(12, 16) weeks. By the modified Merle d'Aubigné & Poster scoring system, the hip function was evaluated at the last follow-up as excellent in 4 cases, as good in 14 cases, and as fair in 1 case. Follow-ups revealed injury to the lateral femoral cutaneous nerve after surgery in 11 patients, of whom 5 were fully recovered and 6 partially recovered after treatment. Ectopic ossification developed after surgery in 3 patients, of whom 1 was rated as Brooker grade Ⅰ and 2 were as Brooker grade Ⅱ.Conclusion:In the treatment of acetabular fractures involving the roof column and roof wall, fixation with plates and screws through the iliofemoral approach or its modified approaches may achieve fine clinical outcomes in addition to the advantages of operative convenience and high safety.

Objective:To compare the effect of reduction and internal fixation of composite acetabular fracture with the modified two-window iliofemoral approach and ilioinguinal approach.Methods:A retrospective cohort study was used to analyze the clinical data of 160 patients with composite acetabular fracture admitted to First Affiliated Hospital of Nanjing Medical University from January 2016 to August 2021, including 117 males and 43 females, aged 15-78 years [(44.1±16.0)years]. According to the Letournel classification system, there were 101 patients with both-column fracture, 5 with anterior wall/column combined with posterior semi-transverse fracture and 24 with T-shaped fracture. A total of 80 patients were treated using the modified iliofemoral incision combined with limited Pfannstiel incision (modified two-window iliofemoral approach group) and the other 80 patients were treated using the ilioinguinal approach (ilioinguinal approach group). The fracture healing was observed. The operation time and intraoperative bleeding volume were compared between the two groups. The quality of fracture reduction was evaluated by Matta scoring standard at 1 day and 6 months after operation. The modified Merle d′Aubigne & Postel scoring standard was used to evaluate the function of the affected hip joint at the last follow-up. The incidence of complications such as neurovascular injury, iatrogenic bladder injury, heterotopic ossification and femoral head necrosis were compared between the two groups.Results:All patients were followed up for 12-78 months [(43.3±17.9)months], with bony union of the fracture. The operation time and intraoperative bleeding volume in modified two-window iliofemoral approach group were 150.0 (123.8, 180.0)minutes and 600.0 (500.0, 787.5)ml when compared to 190.0 (150.0, 240.0)minutes and 700.0 (562.5, 887.5)ml in ilioinguinal approach group (all P<0.01). There was no significant difference between the two groups in the quality of fracture reduction at 1 day and 6 months after operation, function of hip joint at the last follow-up and incidence of complications (all P>0.05). Conclusions:For reduction and internal fixation of composite acetabular fracture, the modified two-window iliofemoral approach has advantages over the ilioinguinal approach in reducing operation time and intraoperative bleeding, although both methods yield similar results in fracture reduction quality, postoperative hip function and complication rate.

Objective:To compare the clinical efficacy of anatomical reconstruction of coracoclavicular ligament at the original insertion point and clavicular hook plate fixation in the treatment of acromioclavicular joint dislocation.Methods:Retrospective analysis was made on the data of 67 patients with acromioclavicular joint dislocation who received surgical treatment in the Department of Orthopaedics of the First Affiliated Hospital of Nanjing Medical University from June 2015 to January 2021. According to the surgical method, they were divided into reconstruction group (using the technique of anatomical reconstruction of coracoclavicular ligament at the original insertion point) and hook plate group (using the clavicular hook plate). There were 37 cases in the reconstruction group, including 26 males and 11 females, aged 47.2±9.6 years (range, 18-65 years), 13 cases on the left and 24 cases on the right. Among the 37 patients, 8 were sports injuries, 14 were falls, 11 were traffic accidents, and 4 were external force injuries. The average time from injury to surgery was 8.3±2.3 days. There were 30 cases in the hook plate group, including 24 males and 6 females, aged 47.4±9.7 years (range, 18-67 years), 12 cases on the left and 18 cases on the right. Among the 30 patients, 7 were sports injuries, 11 were falls, 9 were traffic accidents, and 3 were external force injuries. The average time from injury to surgery was 7.9±2.6 days. The surgical time, incision length, intraoperative bleeding, hospital stay, postoperative coracoclavicular separation ratio, and postoperative complications were compared between the two groups. Constant-Murley score and visual analog scale (VAS) were used to assess the shoulder joint function and pain degree of patients.Results:Both groups of patients were followed up, with a follow-up time of 12.3±0.4 months for the reconstruction group and 12.2±0.5 months for the hook plate group. The operation time (105.8±10.0 min), incision length [12.0 (11.0, 13.0) cm] and hospitalization time (6.8±2.1 d) in the reconstruction group were longer than those in the hook plate group [48.3±4.9 min, 10.0 (10.0, 11.0) cm, and 5.5±2.7 d], while the intraoperative blood loss (75.1±3.9 ml) was less than that in the hook plate group (90.3±6.3 ml), the differences were statistically significant ( P<0.05). The VAS [4.0 (3.0, 5.0), 3.0 (3.0, 3.0), 2.0 (1.0, 2.0) points] and Constant-Murley score (65.4±4.5, 84.9±2.5, 90.1±2.5 points) of the reconstruction group at 3 days, 3 months, and 12 months after surgery were better than those of the hook plate group [5.0 (4.0, 5.0), 4.0 (4.0, 4.0), 3.0 (3.0, 4.0) and 56.9±3.5, 79.6±4.0, 86.8±2.4 points], the difference was statistically significant ( P<0.05). At the last follow-up, there was a statistically significant difference in the separation ratio of coracoclavicular distance between the reconstruction group (0.12±0.08) and the hook plate group 0.22±0.15 ( t=3.25, P=0.002). There was no significant difference ( Z=-0.52, P=0.605) in the separation ratio of acromioclavicular distance [0.16 (0.05, 0.25) and 0.16 (0.04, 0.40)]. In the hook plate group, 6 cases had shoulder joint foreign body sensation and 2 cases had acromioclavicular joint redislocation (both Rockwood type III). Because the shoulder joint function did not affect their daily life, neither patient underwent secondary surgery. And no case of acromioclavicular joint redislocation occurred in the reconstruction group. Conclusion:Compared with the clavicular hook plate fixation, anatomic reconstruction of coracoclavicular ligament at the original insertion point in the treatment of acromioclavicular joint dislocation can reduce the pain of the shoulder joint earlier, which has the characteristics of small trauma, good effect, and reduces the steps of internal fixation removal, and has good clinical curative effect.

Objective:To provide anatomic data of the coracoclavicular (CC) ligament attachment regions in Chinese population for anatomic reconstruction of CC ligament to treat acromioclavicular dislocation.Methods:The CC ligaments were first dissected layer by layer out of the bilateral acromioclavicular joint specimens taken from 87 adult cadavers. The CC width and thickness on the attachments of the clavicle and the coracoid process were measured by an electronic digital caliper. The conoid ligament and trapezoid ligament were mapped on the surface of the clavicle and the coracoid process by transecting the ligaments close to their insertions. The distances from the ligament footprint center to the lateral, anterior and posterior margins of the clavicle were measured. The distances from the ligament footprint center to the tip, medial and lateral margin borders of the coracoid process were measured.Results:The distances from the lateral edge of the clavicle to the footprint centers of the conoid and trapezoid ligaments were (35.7 ± 3.4) mm and (21.8 ± 2.7) mm, and the ratio of the distance divided by the clavicular length was 25.5% ± 0.9% and 15.6% ± 1.1%, respectively. The distances from the tip of coracoid to the footprint centers of the conoid and trapezoid ligaments were (35.1 ± 3.2) mm and (29.7 ± 2.9) mm, and the ratio of the distances divided by the coracoidal length was 86.7% ± 1.9% and 73.3% ± 2.1%, respectively.Conclusion:Although the absolute position of the CC ligament attaching to the clavicle and the coracoid process varies greatly among Chinese individuals, the ratio of its relative position to the length and width of the clavicle and the coracoid process is a relatively stable set of data.

Objective:To compare the clinical efficacy between coracoclavicular ligament anatomical reconstruction and clavicular hook plate in the treatment of Neer Ⅱb distal clavicular fractures.Methods:A total of 64 patients with Neer Ⅱb clavicular fracture were treated at Department of Orthopaedics, The First Affiliated Hospital to Nanjing Medical University from September 2016 to June 2019. They were 35 males and 29 females, aged from 19 to 68 years (average, 50.7 years). They were assigned into 2 groups according to their operative methods: a reconstruction group of 30 cases undergoing coracoclavicular ligament anatomical reconstruction and a hook plate group of 34 cases undergoing fixation with a clavicular hook plate. The 2 groups were compared in terms of hospital stay, operation time, intraoperative blood loss, surgical incision length, postoperative coracoclavicular separation ratio, visual analogue scale (VAS) and Constant-Murley shoulder scores at 3, 6 and 12 months after operation, and postoperative complications.Results:There was no significant difference in general data between the 2 groups, showing comparability between groups ( P>0.05). Operations were completed uneventfully and surgical incisions healed by primary intention in both groups after operation. All the patients were followed up for 12 to 24 months (average, 14.6 months). The operation time [(74.6±22.0) min] and incision length [(10.4±0.4) cm] were significantly shorter but the intraoperative blood loss [(90.2±5.3) mL] was significantly less in the hook plate group than those in the reconstruction group [(95.6±20.8) min, (12.4±0.9) cm and (74.2±3.5) mL] ( P<0.05). There was no significant difference in hospital stay between the 2 groups ( P>0.05). At 3, 6 and 12 months after operation, the VAS scores (1.8±0.5, 1.2±0.3 and 1.1±0.2) and Constant-Murley scores (85.2±4.6, 91.1±2.6 and 92.1±2.2) in the reconstruction group were significantly better than those in the hook plate group (3.2±1.0, 1.6±0.3 and 1.5±0.3; 73.6±2.9, 85.9±4.6 and 87.0±3.1) ( P<0.05). At the last follow-up, the postoperative coracoclavicular separation ratio (elevation) in the hook plate group (0.20±0.16) was significantly greater than that in the reconstruction group (0.10±0.05) ( P<0.05). Conclusion:In the treatment of Neer ⅡB distal clavicular fractures, coracoclavicular ligament anatomical reconstruction may lead to better fixation and fewer postoperative complications than a clavicular hook plate, demonstrating fine clinical efficacy.

Objective:To conduct an MRI observation on the incidences of ligamentous injuries and fracture morphology in Schatzker type Ⅳ tibial plateau fracture (TPF) and investigate their influence on knee stability.Methods:A retrospective analysis was conducted of the 30 patients with Schatzker type Ⅳ TPF who had undergone surgery at Department of Orthopaedic Trauma, Jiangsu Provincial People's Hospital from January 2010 to December 2019 and whose preoperative X-ray, CT and MRI were available. They were 18 males and 12 females, aged from 22 to 75 years (mean, 45.4 years). They were divided into a dislocation-free group and a dislocation group according to the absence or presence of knee dislocation on their anteroposterior X-ray films. The fracture morphology was assessed on CT according to the modified three-column classification. The incidences of ligamentous injuries [involving anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), posterolateral complex (PLC) and anterolateral ligament (ALL)] were investigated on MRI. The 2 groups were compared in fracture morphology and incidences of ligamentous injuries. Multiple linear regression (MLR) analysis was used to identify the main factor contributing to preoperative knee dislocation.Results:The dislocation group had 12 patients and the dislocation-free group 18. The fracture involving medial+posteromedial+posterolateral columns was found in 66.7% of the patients (20 cases), and accounted for 83.3% (10 cases) in the dislocation group. The incidence was 96.7% (29 cases) for ACL injury, 43.3% (13 cases) for PCL injury, 70.0% (21 cases) for MCL injury, 90% (27 cases) for PLC injury, 73.3% (22 cases) for ALL injury and 90% (27 cases) for the multiple-ligament disruption. There was a significant difference in the posterolateral column injury between the dislocation-free group [55.6% (10/18)] and the dislocation group [91.7% (11/12)] ( P < 0.05), but there were no significant differences between the 2 group in the injury to any other single ligament or multiple ligaments ( P>0.05). The MLR analysis confirmed that the posterolateral column injury was a risk factor for coronary plane dislocation in Schatzker type Ⅳ TPF( P<0.05). Conclusions:In Schatzker type Ⅳ TPF, the incidences of ligamentous injuries are very high but the fracture of posterolateral column may be the main cause for preoperative knee dislocation in some patients.