Objective To compare the biomechanical characteristics of the less invasive stabilization system (LISS) and the dynamic condylar screw (DCS) in the fixation of subtrochanteric fractures of the femur so as to provide theoretical basis for choosing internal fixator in clinical application. Methods Twelve cadaveric human femurs (35-50 years old) were selected with similar proximal femur, excluding deformities, fractures, and other lesions. The twelve femur specimens were randomly divided into 2 groups, 6 specimens per group. An 1 cm gap of osteotomy model was made in the proximal femur up to 1 cm below the lesser trochanter to simulate a comminuted subtrochanteric fracture of femur, and the distal end was embedded with denture acrylic and liquid for denture acrylic. Fracture was fixed by LISS in group A, and was fixed by DCS in group B. The specimens were fixed on Instron-8874 servo-hydraulic mechanical testing machine in a single-leg standing position, and the axial compression test and dynamic fatigue test were carried out to compare the compressive strength and the strain distribution at both sides of the fracture line. Results Axial compression test: the strain values of the 2 strain gauges in group A were significantly smaller than those in group B (P lt; 0.01); the vertical down displacement of the femoral head in group A was significantly smaller than that in group B (P lt; 0.01) under the same load; when the load was 600 N, the axial rigidity of group A was (209.06 ± 18.63) N/mm, which was significantly higher than that of group B [(65.79 ± 7.26) N/mm] (t=3.787, P=0.004). Dynamic fatigue test: the vertical down displacement of the femoral head in group A was significantly smaller than that in group B in the same cyclic loading cycle (P lt; 0.01); when the vertical down displacement of the femoral head was 0.5 mm, the force and the cyclic loading cycles in group A were significantly larger than those in group B (P lt; 0.01). Conclusion LISS, which has good mechanical stability, can meet the requirements for subtrochanteric fracture of femur fixation in biomechanics and anatomical structures. It can be proven that the LISS internal fixator is firmer than the DCS internal fixator by biomechanical comparison.
To evaluate the cl inical results of less invasive stabil ization system (LISS) for femur supercondylar and intercondylar fractures. Methods From March 2004 to November 2005, 47 patients with 49 intercondylar and supercondylar fractures were treated. Of all the patients, there were 34 males and 13 females with an average of 39.7 years (range 19-56 years). The locations were left side in 21 cases and right side in 28 cases. Fracture was caused by traffic accident in 31 cases, fall ing in 8 cases, violence in 6 cases and others in 2 cases. Forty-nine fractures included 14 intercondylar fractures, 21supercondylar fractures and 14 intercondylar and supercondylar fractures; 32 closed fractures and 17 open fractures. According to the AO typing, there were 6 type 33-A1, 8 type 33-A2 , 10 type 33-A3, 7 type 33-C1, 3 type 33-C2 and 15 type 33-C3. The disease course was 30 minutes to 6 days. Articular surface reduction was first performed, then the LISS plate was inserted via two incisions and locking screws were used later. Results The average operation time was 126 minutes (range 48-248 minutes). The blood loss was 180 mL(range 60-1 200 mL). The average follow-up time was 18.6 months (range 12-23 months). There were 4 patients with AP angular deformity and 5 patients with lateral angular deformity (range 2-5°). External rotation deformity was presented in 2 patients. There were no plate breakage, screw loosen and fixation failure. Average bone union time was 5.6 months (range 3-8 months) without infection case. Six cases were treated with il iac bone transplantation for delayed union. Conclusion LISS is one kind of effective treatment to femoral intercondylar and supercondylar fractures.
To investigate the therapeutic effects and the related factors during operation of the less invasive stabilization systemdistal femur（LISSDF）for Types 33A3, C2 and C3 fractures classfied on the criteria by Association of Orthopedics (AO). Methods From August 2004 to December 2005, 26 patients with distal femoral fractures were surgically treated by LISSDF, including 9 patients with Type 33A3, 11 with Type 33C2, and 6 with Type 33C3. There were 15 males and 11 females, aged 3272 years (average, 55 years). The fractures occurred on the left side in 16 patients and on the right side in 10 patients. The fractures resulted from a road traffic accident in12 patients, a fall from the height in 9, and a crush injury in 5. Of the 26 patients, 3 had an open fracture (2 Gustilo Type Ⅰ,1 Gustilo Type ⅡA), with the mean time between the injury and the operation of 4 days (range, 6 h16 d).The operation through a lateral parapatellar incision and a transarticular retrograde plate of osteosynthesis (TARPO) was performed on 17 patients for Type33C2 and 33C3 fracture of the distal femur. The locking head screw (LHS) insertion through the stab incisions and monocortical fixation was performed on 9 patients for Type 33A3 fracture. Results The followup of all the patients for 12-26 months averaged 14.5 months revealed that the bone union was completed in all the 26 patients, 1 of whom had a delayed bone union. The X-ray films showed that the time for the bone union was 1136 weeks averaged 16.1weeks, and the time for the full weight loading was 1326 weeks averaged 17.6 weeks. Superficial infection developed in 1 patient, and the infection was curedafter the dressing changes. The internal fixator attachment was performed on 5 patients 613 months after operation, who had a serious pain in the lateral part of the distal femur. No deep infection，loosening of the internal fixation，breakage or failure of the implants was found in all the patients. Evaluated by the Merchant score system for the knee joint, of the 26 patients 13 achieved an excellent result, 11 achieved a good result, and 2 achieved a fair result, with 92.3% excellent and good results. Based on the Rasmussen criteria for the fracture reduction, the 26 patients had standard scores of 1219 with an average of 17.6; of the 26 patients, 16 had an excellent result, 9 had a good result, and 1 had a fair result. Conclusion The LISS is consistent with the principles of biological osteosynthesis on the design, and the system offers a new and effective internal fixation method for treatment of AO Types A3, C2 and C3 fractures. However, its operation indications and operating instructions should be strictly followed.
Objective To study the clinical outcome of comminuted factures at distal femur and proximal tibia treated with AO less invasive stabilization systems (LISS). Methods The clinical data of 14 cases of distal femoral fracture and proximal tibial fracture from September 2003 to May 2005 were analyzed retrospectively. The injury was caused by traffic accident in 9 cases, by fall in 3 cases and by slipping in 2 cases. Of 14 cases, there were 5 open fractures and 9 close fractures, including 5 cases of distal femoral comminuted fracture and 9 cases of proximal shaft comminuted fractures. According to AO/OTA classification, the fractures were classified as 33C2 in 3 cases，33C3 in 2 cases,41A2 in 2 cases，41A3 in 2 cases，41B2 in 3 cases and 41C2 in 2 cases. All patients were treated by the internal fixation with LISS-distal femur or with LISS-proximal tibia. Healing of wounds, the X-ray films before and after operations, and therecovery of joint function were observed. Results The patients were followed up from 1 month to 20 months (11 months on average). Twelve cases achieved solid osseous unions from 3 months to 5 months postoperativly; 2 cases had a good reduction and recovered smoothly 2-3 months postoperatively. The results were excellent in 10 cases, good in 3 cases and fair in 1 case according to Johner-Wruhs knee scoring. The range of knee flexion-extension was 110-130° in 11 cases, 100° in 2 cases and 80° in 1 case. Conclusion LISS is an effective method of internal fixation for treating comminntedfracture of distal femur or proximal tibia. It has the advantages of less injury, satisfied reduction and reliable fixation.
ObjectiveTo explore the effectiveness of three different operative methods in the treatment of closed fracture of the tibial shaft. MethodsBetween January 2012 and May 2014, 94 patients with closed fracture of the tibial shaft were treated, and the clinical data were retrospectively analyzed. Fracture was fixed with locking plate (external fixation) in 25 cases (group A), with intramedullary nail in 34 cases (group B), and with minimally invasive locking plate in 35 cases (group C). There was no significant difference in gender, age, reasons of injury, fracture types, and time from injury to operation among groups (P>0.05). The operation time, intraoperative blood loss, fluoroscopy frequency during operation, fracture union time, and complications were recorded. The effectiveness was evaluated according to Johner-Wruhs criteria. ResultsThe operation time and fluoroscopy frequency during operation in groups A and C were significantly less than those in group B (P<0.05), but there was no significant difference between groups A and C (P>0.05). The intraoperative blood loss in groups A and C was significantly less than that in group B (P<0.05), and the blood loss in group A was significantly less than that in group C (P<0.05). All patients were followed up 15.61 months on average (range, 12-41 months). There was no significant difference in fracture union time among 3 groups (F=1.712, P=0.186). The excellent and good rates of groups A, B, and C were 92.00%, 88.24%, and 91.43% respectively according to Johner-Wruhs criteria at 12 months after operation, showing no significant difference (χ2=0.301, P=0.860). At 12 months after operation, the complication incidences of groups A (12.00%, 3/25), and C (15.55%, 5/35) were significantly lower than that of group B (44.12%, 15/34) (P<0.017), but no significant difference was found between groups A and C (P>0.017). ConclusionUsing locking plate as external fixation and minimally invasive locking plate internal fixation are better than intramedullary nail fixation in treating closed fracture of tibial shaft because of less injury and lower complication incidence, and locking plate as external fixation is better than minimally invasive locking plate internal fixation because of less injury.
ObjectiveTo explore the early effectiveness and advantages of mini-Swashbuckler approach in treatment of distal femoral type C fractures by comparing with Swashbuckler approach.MethodsA retrospective analysis was made on 43 patients with distal femoral type C fractures between January 2014 and June 2018. Twenty-two patients were treated with open reduction via mini-Swashbuckler approach and internal fixation with less invasive stabilization system (LISS) plate in modified group; and 21 patients were treated with open reduction via Swashbuckler approach and internal fixation with LISS plate in traditional group. There was no significant difference in age, gender, cause of trauma, fracture classification, fracture side, interval between injury and operation, and complications between the two groups (P>0.05). The operation time, intraoperative blood loss, intraoperative fluoroscopy times, hospitalization time, fracture healing time, Hospital for Special Surgery (HSS) scores of the knee, and postoperative complications were recorded and compared between the two groups.ResultsThe operation successfully completed in both groups. The operation time of the modified group was significantly longer than that of the traditional group, the fluoroscopy times was increased and the blood loss was reduced, the differences were significant (P<0.05). There was no significant difference in hospitalization time between the two groups (t=0.277, P=0.783). All patients in the two groups were followed up 6-8 months, with an average of 7.2 months. Fractures healed in both groups, there was no significant difference in healing time between the two groups (t=0.861, P=0.394). The HSS scores of the modified group were 82.91±2.88 and 89.28±3.63 at 3 and 6 months after operation, respectively, which were superior to those of the traditional group (74.62±3.64) and (81.48±4.55) (t=8.306, P=0.000; t=6.231, P=0.000). There was 1 case of incision infection, 1 case of deep vein thrombosis, and 2 cases of knee flexion and extension dysfunction in traditional group, and 1 case of deep vein thrombosis, 1 case of varus deformity, and 1 case of internal fixation loosening in modified group. There was no significant difference in the incidences of complications between the two groups (P>0.05).ConclusionCompared with Swashbuckler approach, mini-Swashbuckler approach has limited visual field exposure, which leads to prolonged operation time and increased fluoroscopy times, but the risks of complications do not increase. Because of its small soft tissue injury and less blood loss, it is conducive to the recovery of knee joint function after operation.
Objective To explore the application value and effectiveness of pelvic unlocking closed reduction device for the treatment of unstable pelvic posterior ring disruption. Methods A retrospective analysis of clinical data of 243 cases of unstable pelvic posterior ring disruption treated with pelvic unlocking closed reduction device in 13 orthopaedic trauma centers across the country between December 2018 and June 2020 was performed. There were 139 males and 104 females; the age ranged from 18 to 92 years, with an average age of 48.5 years. The cause of injury included 132 cases of traffic accident injuries, 102 cases of falling from height, and 9 cases of crushing injuries. According to AO/Orthopaedic Trauma Association (AO/OTA) classification, there were 5 cases of type 61-B1, 13 cases of type 61-B2, 32 cases of type 61-C1.1, 47 cases of type 61-C1.2, 89 cases of type 61-C1.3, 35 cases of type 61-C2, and 22 cases of type 61-C3. The time from injury to operation was 2-121 days, with a median of 10 days. Preoperative preparation time, installation time of unlocking closed reduction device, fracture reduction time, intraoperative fluoroscopy times, intraoperative blood loss, and surgical complications were recorded, and Matta scoring standard was used to evaluate the quality of fracture reduction. According to Matta evaluation results, the patients were divided into two subgroups: excellent-good group and fair-poor group. The differences in gender, age, time from injury to operation, AO/OTA classification, and perioperative clinical indicators were compared between the two groups, and the effects of baseline data and perioperative indicators on the quality of fracture reduction were studied. Results Pelvic unlocking closed reduction device did not interfere with the display of the pelvic structure and fracture displacement direction during the intraoperative fluoroscopy, effectively correcting the displacement of the pelvic ring. The preoperative preparation time was 17-60 minutes, with an average of 30 minutes; installation time of unlocking closed reduction device was 10-32 minutes, with an average of 21 minutes; intraoperative fracture reduction time was 15-205 minutes, with an average of 49.2 minutes; intraoperative fluoroscopy times were 41-420 times, with an average of 132 times; intraoperative blood loss was 40-1 500 mL, with an average of 71.5 mL. The reduction quality of pelvic fracture was evaluated according to Matta score immediately after operation. The results were excellent in 153 cases, good in 61 cases, fair in 24 cases, and poor in 5 cases. The excellent and good rate was 88.1%. Further subgroup analysis showed that there was no significant difference in other indexes (P>0.05) between the excellent-good group and the fair-poor group except for the time from injury to operation and AO/OTA classification (P<0.05). Among them, the excellent-good reduction rate was 92.2% (119/129) in patients with injury-to-operation time less than 10 days, and the fair-poor reduction rate was 25.7% (9/35) and 40.9% (9/22) in patients with AO/OTA 61-C2 and 61-C3 types, respectively. There was no surgery-related complication due to the application of the pelvic unlocked reduction device, no secondary iliac fractures, vascular, or nerve injuries, and postoperative CT showed that all channel screws were located in the osseous channel. ConclusionThe pelvic unlocking reduction device can effectively help to reduce the unstable pelvic posterior ring and maintain reduction, meet the needs of different projection angles of pelvic fracture with intraoperative C-arm fluoroscopy. The system facilitate the operation of pelvic reduction and precise fixation.