Objective To review the research progress of P75 neurotrophin receptor (P75NTR) so as to clarify its mechanism, and to explore its relationship with nonunion so as to provide a new idea for the treatment of nonunion. Methods The related domestic and foreign literature of P75NTR in recent years was extensively reviewed, summarized, and analyzed to find out the mechanism of action of P75NTR and the pathological factors of nonunion formation. Results P75NTR can express in nonunion tissues and lead to defect of fibrin degradation and inhibition of angiogenesis, which play an important role in the pathogenesis of nonunion. Conclusion It needs to be confirmed by further study whether the purpose of treating nonunion can be achieved by blocking the effects described above of P75NTR.
OBJECTIVE: To present a surgical choice for nonunion and bone defect. METHODS: From November 1994 to October 1997, 17 cases of nonunion of fracture and massive bone defect were treated by autogenous iliac bone and fibular bone with vascular anastomosis. Of 17 cases, there were 10 cases of nonunion of bone fracture, 7 cases of bone defect following tumor resection (4 cases of benign and 3 cases of malignant). Autogenous fibular bone grafting with vascular anastomosis, ranging from 12 cm to 29 cm in length, were employed in 12 cases; autogenous iliac bone grafting, ranging from 7 cm x 3 cm to 9 cm x 5 cm in size, were utilized in the other 5 cases. All of 17 cases were followed up for 10 months to 5 years, 3 years and 7 months in average, and were evaluated from clinical manifestation. RESULTS: Bone union was achieved in 10 cases of nonunion of fracture after bone grafting, bony refilling of the bone defect was observed in 4 cases due to benign tumor and 1 case due to malignant tumor. The other 2 cases of malignant tumor died from lung metastasis of the tumor 10 months and 12 months after bone grafting, respectively. CONCLUSION: Bone grafting is an effective surgical option in treatment of nonunion of fracture and bone defect.
In order to investigate the blood supply of osteo-periosteal flap of lateral inferior part of tibia, 40 lower limbs of adult cadavers were observed. The result showed that the superior malleolar branch was the biggest branch on the lateral inferior part of tibia and served as the main blood supply to the above area. It originated from the anterior tibial artery, 3.1 +/- 0.8 cm above the intermalleolar line. During its way to the anterior border of the tibia, it gave out the ascending and descending branches. The ascending branch was along the anterior border upward and anastomosed with the musculo-periosteol branch of the anterior tibial artery at the level of 6.3 +/- 1.3 cm above the intermalleolar line. The decending branch was anastomosed with the anterior medial malleolar artery. For the anastomosis between the superior malleolar branch with the peripheral vessels, the osteo-periosteol flap could be designed at the lateral side of the lower part of tibia in size of 8-10 cm x 4-6 cm. This was a new donor area of osteo-periosteol flap for repair of non-union of bone in lower end of tibia or arthrodesis of the ankle joint.
Objective To explore an ideal operative treatment to preserve the hi p joint for the old femoral neck fracture in young and middle-aged patients. Methods Between January 2002 and June 2006, 28 cases of old femoral neck fracture, 23 males and 5 females, aged 19-55 years old (37.6 on average), were reconstructed with free il iac grafts and fixed by dynamic hi p screws (DHS) and/or canulated screws. Multi ple vascular bundles derived from lateral circumflex femoral vascular were implanted in 19 cases. All the 28 cases were close fractures, with 17 of left hip and 11 of right hip. In terms of the fracture site, 4 cases were infer-head, 17 were per-neck and 7 were fundamental-form. The Harris score was 25-72 (49.6 onaverage) before operation. No callus formation was found on X-ray films in all cases; sclerosis and cyst were found in 4 cases and osteonecrosis of femoral head (ONFH) was confirmed by MRI. The duration between initial injury and surgery was 1-21 months (8.6 months on average). Results No deep infection was observed in all 28 cases, and paralysis of the lateral cutaneous nerve of the thigh was observed in 5 cases, and was better 6 months after operation with no special treatment. All 28 cases were followed up for 20-72 months (35.8 months on average). A total of 25 fractures healed within 4-8 months, with the heal ing rate of 89.3%; 3 fractures had nonunion and received artificial hip replacement. During the follow-up, 7 cases (25%) developed ONFH confirmed by MRI within 18 months, and 5 cases (17.9%) developed femoral head collapse. The Harris score was 27-100 (82.7 on average). Leg length discrepancy was not observed and the gait was fairly normal. Conclusion The femoral neck reconstruction procedure can restore the normal anatomy of femoral head and neck and the blood supply, so as to promote fracture heal ing as well as delay or avoid the artificial joint replacement. Therefore, it is an important treatment to preserve the hip joint for the old femoral neck fracture in young and middle-aged patients.