Objective To investigate the functional changes of osteoblasts in female SD rats in vivo at different phases following ovariectomy and to analyze their mechanism. Methods 40 female SD rats aged 6 months were randomly divided into 2 groups: the sham operated group and the ovariectomized (OVX) group. During the 4-month experiment, 10 rats from each group were sacrificed to have the serum and the 4th lumbar vertebrae specimens at the end of the 2nd week and the 16th week respectively. Serum bone gla protein (BGP), serum bone specific alkaline phosphatase (BALP) were measured. The excretive function and morphologic changes of the osteoblasts were observed under TEM (Transmission Electronic Microscope). Results In the OVX group, the levels of BGP and BALP all increased at the end of the 2nd week, but showed no significant difference from those in the control group at the end of the 16th week. TEM indicated osteoblasts were activated at the end of the 2nd week, but tended to be inactivated in the ovariectomized group at the end of the 16th week. Conclusions When estrogen decreases in ovariectomized rats, osteoblasts experience a short activated period, but their capacity of bone formation decreases in the end. Abnormal function of osteoblasts may play an important role in pathogenesis of osteoporosis.

It is a clinically tough problem to repair compound tissue d efects of limbs. Application of microsurgical technique with autologous pedicel or free tissue grafts has saved numerous invalid limbs with tissue defects, and is still an essential method to restore compound tissue defects of limbs and res love effectively many difficult problems, such as larger solf tissue defects,seg mental bone defects, bone-skin compound defect, and etc. Microsurgical repair i n emergency has special value in treating compound tissue defects of hand. Altho ugh the resource of autologous tissue graft as donator is limited, tissue engine ering and gene technology hold the promise of revolutionary advances in repairin g compound tissue defects of limbs. Because of the achievements made in the fiel ds of trauma repair and tissue regeneration, both structure and function will be hopefully restored.

Proximal tibial fractures, especially high energy ones, can incur unique challenges in clinical treatment. Soft tissue is injured from both fracture and surgical dissection; the fracture often brings with it neurovascular problems; it is difficult to reduce and stabilize proximal fragments. Treatment strategies of dealing with associated injuries, accurate diagnosis, and selection of individualized method for reduction and fixation are emphasized. Soft tissue protection should always be kept in mind during operation.

Complex Pilon fracture is always a challenge to orthopaedic surgeons. Careful assessment of the injury, especially the soft tissue condition, is essential for a proper treatment planning. Classification of the fracture is also important for evaluation of the prognosis. Treatment planning includes: timing of the surgery, selection of the fixation method and postoperative protocols. In this article, on the basis of literature review and personal experience, the author suggests criteria for injury assessment and postoperative treatment. A brief comparison of different kinds of fixation is made and the principle of implant selection is discussed in the text.

Objective To evaluate effects of minimal invasive plating for treatment of mid-distal humeral shaft fractures.Methods From May 2004 to December 2007, 20 patients with isolated unilat-eral mid-distal third humeral shaft fractures were surgically treated with close reduction and internal fixation using a 4.5 mm dynamic compression plate which was anteriorly inserted through 2 small incisions on the anterior aspects of proximal and distal parts of the arm, away from the fracture site.The postoperative function of the radial nerve and the musculocutaneous nerve, the postoperative alignment of the main fragments on the anteroposterior radiographs, the bone healing time and muscle strength of biceps muscles were measured and recorded, Results Four patients complained of numbness at the area innervated by the lateral ante-braehial cutaneous nerve in the affected forearm after the surgery.No signs of iatrogenic radial nerve palsies occurred after the surgery.A completely normal alignment was achieved in 7 patients, but varus of 11° was found in 2 cases and varus of 2°, 3°, 4°, 5°, 6°, 7° and 10° in one each.Valgus deformity was noticed in 4 cases, and valgus of 3°, 4°, 6° and 7° in one each.The mean follow-up of 10.4 months for 19 patients re-vealed bony union of all the fractures.The average bone healing time was 13.4 weeks.At the latest follow-up, the biceps muscle strength of all the patients was 5 degrees.Hardwires were removed in 5 patients without any complications.Conclusions Minimally invasive anterior plating is a safe alternative osteosynthesis for mid-distal third humeral shaft fractures.However, this technique may interfere with the function of the lateral antebrachial cutaneous nerve.

Objective To report the clinical results of the treatment of proximal humeral fractures with a locking proximal humeral plate (LPHP) through a small skin incision on the anterolateral shoulder. Methods In the period from May 2004 to June 2005, 17 cases of proximal humeral fractures were treated in our department. There were 3 Neer two-part fractures, 10 Neer 3-part ones and 4 Neer 4-part ones. Starting from 1.5cm anterior to the acromion, the skin was incised for 6 cm in length and the deltoid muscle was separated along the muscle fibers to expose the fracture fragments. Under direct vision the indirect reduction of the fracture was performed and the fragments were temporarily fixed with K-wires. The LPHP was inserted distally beneath the deltoid muscle and the position between the distal plate and the humeral shaft was adjusted through another small skin incision on the lateral upper arm. 4 locking screws were inserted to the proximal plate to fix the fracture fragments while screws were percutaneously inserted to the distal plate to fix it to the humeral shaft. Results This series experienced a primary wound healing, a mean operation time of (128?35) min, a mean intraoperative blood loss of 65?19 mL, and an average hospitalization of 4 days. A follow-up of mean 6.1 months, ranging from 3 months to 14 months, was performed in 12 cases of the 17 and revealed fracture union in all, with a mean healing time of 15.7 (ranging from 12 to 24) weeks. The final follow-up demonstrated a normal sensation on the lateral arms and a motion range in shoulder abduction of 80?to 150?and flexion of 80?to 160?. Conclusion The treatment of proximal humeral fractures by open reduction and internal fixation with LPHP through a small skin incision on the anterolateral shoulder has the advantages of simplifying operative maneuver, reducing tissue damage, decreasing blood loss, shortening bone healing time and improving functional recovery.

Objective To compare and analyze the biomechanical strengths of 4 different fixations for the posterolateral shearing tibial plateau fracture. Methods The posterolateral shearing fracture models were created in 40 synthetic tibia (SYNBONE, right) and randomly assigned into 4 groups. Group A was instrumented with 2 lag screws, group B with anteromedial LC-DCP, group C with lateral locking plate,and group D with posterolateral buttress plate. Vertical displacements of the posterolateral fragments and failure loads were measured under axial loads from 500 N to 1500 N. Results The vertical displacements in groups A, B, C and D were respectively(0. 459 ±0. 045) mm, (0. 365 ±0. 035) mm, (0. 264 ±0. 025)mm and (0. 128 ± 0. 018) mm under axial loads of 500 N, (1. 058 ± 0. 091 ) mm, (0. 882 ± 0. 053 ) mm,(0.551±0.053) mm and (0.440±0.068) mm under 1000 N, and (1.559±0.097) mm, (1.466±0. 079) mm, (1. 291 ±0. 077) mm and (0. 832 ±0. 130) mm under 1500 N. The differences between the 4 groups were statistically significant ( P ＜ 0. 05) . The loads to failure in groups A, B, C and D were respectively (1870 ± 156) N, (2520 ± 186) N, (2816 ± 190) N and (3465 ±210) N. The differences between the 4 groups were statistically significant ( P ＜ 0. 05 ). Conclusion The posterolateral buttress plate may be the biomechanically best fixation method for the posterolateral shearing tibial plateau fracture.

Objective To report the short-term result of unicompartmental knee arthroplasty (UKA) for osteoarthritis and spontaneous osteonecrosis of the knee, and discuss the indications and surgical pitfalls for the procedure as well. Methods From April 1999 to July 2000, unicompartmental knee arthroplasty were performed in 20 cases (24 knees). Osteoarthritis in 18 cases (20 knees) and spontaneous osteonecrosis in 2 cases (2 knees); 10 males (12 knees) and 10 females (12 knees). The range of motion (ROM), femorotibial angle (FTA) and JOA score were adopted as main parameters to evaluate the outcome of the operation. The mean age of the patients at the time of operation was 73.3?7.1 years,and 75.0?6.8 years at the final follow-up. The mean follow-up period was 25.7?15.0 months. The prostheses used in the group were unicompartment sleigh shaped artificial joint of Link Endomodel Sled Knee, Waldemar Link or YCMK. Results Before operation, the mean ROM was from 5.4??6.1?(extension) to 120.0??15.0?(flexion), the flexion deformity was significantly corrected after operation. The average extension was 2.1??2.5? at the time of follow-up, significantly improved comparing with 5.4??6.1? of pre-operation (P

Objective To report the technique and outcome of combined transplantation of bilateral vascularized fibulas to repair the segmental femoral defect Method In the period from October 1984 to May 1992, bilateral vascularized fibula transfer was done to treat femoral defects in 9 cases, in which there were 5 cases of bone tumor, 3 cases of pathological fractures following chronic osteomyelitis and 1 case of posttraumatic bone defect The length of the transferred fibulas ranged from 12 cm to 22 cm and averaged 16.25 cm Result Except 1 case in which thigh amputation was done 6 months after operation because of local recurrence of the chondrosarcoma, all the transferred fibulas united solidly with the host bones 3-6 months after operation The repaired limbs started weight-bearing at the third to seventh postoperative month Conclusion To repair a femoral defect over 10 cm in length, combined transfer of bilateral vascularized fibulas is the treatment of choice with short therapeutic process and good results.

Objective To investigate treatment method for existing and impending benign pathological femoral neck and trochanteric lesions.Methods A retrospective study wad done on 25 patients with benign proximal femur lesions treated between 2002 and 2004.All patients were treated with lesion curettage,cauterization,autografting and/or allografting.Then,dynamic condylar screw (DCS) or hip joint-span external fixator were selected according to the involved area of the lesion of the proximal femur.The duration of follow-up was mean 2.3 years (2-4 years).Results Sound bony union was seen on the radiographs of all patients by 3-6 months after surgery.There found no local recurrence or avascular necrosis of the femoral head,or complications like necrosis,infections or fractures.Function of the patients in the current series was graded excellent,assessed by the validated outcome measures MSTS-87,MSTS-93 and TESS lower extremity.Conclusion DCS or hip joint-span external fixator may be better alternative treatment of benign pathological femoral neck and trochanteric lesions,compared with conventional surgical methods such as simple bone grafting,traction and hip spica cast.