Internal fixator is usually adopted in the treatment of bone fractures. In order to achieve anatomical reduction and effective fixation of fractures, the placement of internal fixators should comply with the biology force line of the bone and adapt to the specific anatomical morphological characteristics of the cortical bone. In order to investigate the distribution characteristics and formation regularity of biology force line and cortical thickness of human bone, three-dimensional model of proximal femur is established by using three-dimensional reconstruction technique in this paper. The normal physiological stress distribution of proximal femur is obtained by finite element analysis under three kinds of behavior conditions: one-legged stance, abduction and adduction. The structural topology optimization method is applied to simulate the cortex of the proximal femur under the combined action of three kinds of behavior conditions, and the anatomic morphological characteristics of the proximal femur are compared. The distribution trend of biology force line of proximal femur and the characteristics of cortex are analyzed. The results show that the biology force lines of bone structure and the morphological characteristics of cortex depend on the load of human activities. The distribution trend of biology force line is related to the direction of trabecular bone and the ridge trend and firmness of cortex when bone is loaded physiologically. The proposed analytical method provides a solution to determine the biology force line of bone and the distribution characteristics of cortex. The conclusions obtained may guide the reasonable placement of internal fixator components of fracture.
Objective To investigate the treatment and effectiveness of inferior polar comminuted fractures of patella and patellar tendon injury. Methods Between January 2003 and December 2008, 5 patients with inferior polar comminuted fractures of patella and patellar tendon injury were treated with Nitinol Patellar Concentrator and fascia lata allograft. There were 3 males and 2 females with a mean age of 33.7 years (range, 20-48 years). The interval of injury and operation was 1-5 days. Fracture degree: 3 cases had 3 fractures of patella, 2 cases had 4 fractures; patellar tendon injury degree: 3cases had horizontal rupture of middle l igament, 1 case had obl ique rupture of tibial tubercle, and 1 case had longitudinal partial rupture. Results Heal ing of incision by first intention was achieved in all patients, and no compl ication of infection or deep venous thrombosis occurred. The X-ray films at 2 days after surgery showed that patella recovered to normal height, which meaned ratio of patella height to patellar tendon length recovered to 1 : 1. Five cases were followed up 18 months on average (range, 10-22 months). At 3-12 weeks after surgery, the knee function of the injury side almost reached that of the normal side in 4 patients, and the knee range of motion was about 100° in 1 patient. The fracture heal ing time was 3-5 months. At 12-15 months after surgery, patella holder was taken out and no lost of reduction or refracture occurred. During follow-up, there was no fracture displacement, loosening and breakage of implant, or rerupture of patellar tendon. According to ZHANG Chuncai’ s criterion for knee joint function, the results were excellent in 3 cases, good in 1 cases, and fair in 1 case with an excellent and good rate of 80%. According to XU Shaoting’s criterion for knee joint function, the results were excellent in 2 cases, good in 2 cases, and fair in 1 case with an excellent and good rate of 80%. Conclusion Nitinol Patellar Concentrator and fascia lata allograft is a new method to treat inferior polar comminuted fractures of patella and patellar tendon injury, and it can ensure the knee joint stabil ity in early motion after surgery.
Objective To investigate the cl inical effect of the acetabular tridimensional memoryalloy-fixation system (ATMFS) in treatment of posterior wall acetabular fractures with posterior dislocation of hip. Methods From January 2004 to February 2006, 15 cases of posterior wall acetabular fracture with posterior dislocation of hip were treated. There were 11males and 4 females, aged 21-68 years old with an average of 43.5 years old. Injury was caused by traffic accident in 8 cases, by fall ing from height in 5 cases and others in 2 cases. The locations were the left hip in 9 cases and the right hip in 6 cases. According to Thompson-Epstein’ fracture classification, there were 6 cases of type II, 5 cases of type III, 2 cases of type IV and 2 cases of type V. Imaging showed the acetabular articular surface displacement of 2-5 mm(mean 3 mm). The time from injury to hospital ization was 6 hours to 2 weeks(mean 1.5 days). Skeletal traction on femoral condyle was given, manual reduction was performed in 12 patients and intra-operative reduction in 3 cases. ATMFS was used after 2-7 days of hospital ization, and 4 cases received autologous free il ium because of bone defect. Results The operative time was 90-390 minutes with an average of 210 minutes. Intraoperative blood loss was 350-2 500 mL with an average of 360 mL. The hospital ization days of the patients ranged from 7 to 21 days(mean 10 days). Epidermal infection occurred and was cured after symptomatic management in 1 case. Other incisions healed by first intention. No deep infections, pulmonary embol ism, deep venous thrombosis and other compl ications occurred. The patients were followed up 1 to 3 years with an average of 1.6 years. Ischemic necrosis of femoral head occurred in 1 case. Heterotopic ossification in grade II occurred in 1 case. The hip function was still good without special treatment. According to Matta’s X-ray fracture reduction assessment, the results were excellent in 7 cases, good in 5 cases, fair in 2 cases, and poor in 1 case, the excellent and good rate was 80%. According to d’Aubigné cl inical efficacy evaluation, the results were excellent in 8 cases, good in 5 cases, fair in 1 case, and poor in 1 case, the excellent and good rate was 86.7% at last followup. Conclusion ATMFS can be used for the treatment of posterior wall acetabular fracture with posterior dislocation of hip, which can improve the anatomy corresponding rate of the femoral head and reduce the incidence of compl ications and restore the function of the hip.
Objective To investigate the effectiveness of acetabular tridimensional memory alloy-fixation system (ATMFS) combined with autologous il iac bone in the treatment of old acetabular posterior wall fracture with bone defect. Methods Between January 2002 and February 2009, 17 patients with old acetabular posterior wall fracture and bone defect were treated, including 11 males and 6 females with an average age of 41.7 years (range，20-60 years). The time from fracture to admission was 14-180 days (mean, 63 days). The displacement of the acetabular articular surface was more than or equal to 3 mm. According to the America Association of Orthopedic Surgeon (AAOS) acetabular fracture and defectclassification standard, there were 4 cases of type I, 6 cases of type II, 5 cases of type III, and 2 cases of type IV. After the residual fracture fragments of the acetabular posterior wall and soft tissue hyperplasia were removed, the femoral head was reducted, and posterior wall defect was repaired with autologous il iac bone graft; ATMFS was used to fix acetabular posterior wall and artificial capsular l igament to reconstruct the hip so as to prevent re-dislocation of the femoral head. Results According to Matta imaging assessment standard, the results were excellent in 8 cases, good in 6 cases, fair in 2 cases, and poor in 1 case with an excellent and good rate of 82.3%. All incisions healed by first intention, and no sciatic nerve injury occurred. All patients were followed up 1-8 years (mean, 3.9 years). The mean time of fracture union was 3.6 months (range, 2-6 months). Avascular necrosis of femoral head occurred in 1 case, heterotopic ossification around the acetabulum in 1 case. According to Merle d’ Aubigné-Postel scoring system evaluation, the cl inical results were excellent in 9 cases, good in 6 cases, fair in 1 case, and poor in 1 case with an excellent and good rate of 88.2%. Conclusion ATMFS combined with autologous il iac bone graft and artificial l igament reconstruction of the hip joint capsule is a good choice for the treatment of old acetabular posterior wall fractures with bone defect, which can resume the posterior hip joint stabil ity and prevent re-dislocation of the femoral head.
Objective To summarize the treatment method and to analyze short-term therapeutic effect of Pipkin fracture. Methods From January 2002 to January 2007, 14 cases of Pipkin fracture were treated. There were 10 males and 4 females with an average of 33.5 years (ranged from 28 to 52 years). Fractures were caused by traffic accident. According to Pipkin’s classification, there were 4 cases of type I, 6 cases of type II, 2 cases of type III and 2 cases of type IV. The time from injury to operation was 24 hours to 8 weeks. All patients received open reduction under Kocher-Langenbeck approach, mel iorative posterior-lateral approach or combined approaches. Absorbable screws and suture l ine internal fixation wereperformed in fracture of the femoral head, titanium cannulated screws were used to fix the femoral intertrochanteric fracture in type III, and acetabular tridimensional memory fixation systems were used to fix the posterior acetabular fractur in type IV. Results All cases had one-stage wound heal ing, no compl ications of deep infection and thrombosis of deep vein of lower l imb occurred. All the patients were followed up for 12 - 48 months (mean 26 months). One case of type III fracture for Pipkin had necrosis of femoral head after 1 year of reduction and fixation, and received total hip replacement; other patients achieved bony heal ing after 6-10 months (mean 8 months). According to D’Aubigue-Postel score, the results were excellent in 5 cases, good in 6 cases, fair in 2 cases and poor in 1 case; the excellent and good rate was 78.6%. Conclusion It is important for the patients with Pipkin fracture to early diagnose, to select proper operation approach, to stably fix fracture and to manage after operation in reducing compl ication and recovering hip joint function.
【Abstract】 Objective To discuss the strategy of condylar reconstruction in the treatment of refractory condylarnonunion and defect of humerus. Methods From September 1998 to September 2005, 18 patients with refractory condylarnonunion concomitant with defect of humerus were treated. The series included 12 males and 6 females, aged 18 to 60 years. Accordingto AO/ASIF system, primal fractures were classified, including 5 cases of type A3, 2 cases of type B1, 4 cases of type C2and 7 cases of type C3 fractures. Condylar nonunion and defect of humerus were confirmed by preoperative X-ray. Defectivebone mass was 1-4 cm2. The mean extension and flexion of elbow joint was 21.5°(5-65°) and 95.8°(85.0-123.5°) respectively. Accordingto Cassebaum scoring system, the excellent and good rate was 27.8% (excellent in 1 case and good in 4 cases). Time frominjury to operation averaged 22.8 months(7-52 months). All patients were operated with approach of olecranon osteotomy.Bone defect was reconstructed with il iac autograft. Shape memory compressive connector, Kirschner wire, cannulated nail, anatomicplates and reconstruction plates were used to fix. Results Eighteen patients were followed up 12-86 months (mean27.6 months). All the incisions healed by first intention. No bone block displacement, loosening or breakage of internal fixationoccurred. The time of bone union averaged 5.7 months(4-8 months). The mean extension and flexion of elbow joint were 11.4°(0-44.5°) and 128.6°(105.5-144.5°) 1 year after operation. Ectopic ossification formed in 1 case at anterior part of elbow 4 monthsafter operation. According to Cassebaum scoring system, the results were excellent in 8 cases, good in 6 cases, fair in 3 cases andpoor in 1 case. The excellent and good rate was 77.8%. Conclusion The shape of humeral condyle can be reconstructed withil iac autograft. Compressive internal fixation of bone block can promote bone union. Anatomical reconstruction, rigid internalfixation and early function exercise can improve the function of elbow joint evidently.