Volume 14 · Issue 04 · 2011

Abstract：Objective: To study the feasibility of regenerating a whole menisci using poly-(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) scaffolds loaded with meniscal cells in rabbits undergoing total meniscectomy, and to explore its protective effect on cartilage degeneration. Methods: A solvent casting and particulate leaching technique was employed to fabricate biodegradable PHBV scaffolds into a meniscal shape. The proliferated meniscal cells were seeded onto the polymer scaffolds, transplanted into rabbit knee joints whose lateral menisci had been removed. Eight to 18 weeks after transplantation, the regenerated neomenisci were evaluated by gross and histological observations. Cartilage degeneration was assessed by Mankin score. Results: Eighteen weeks after transplantation, the implants formed neomenisci. Hematoxylin and eosin (HE) staining of the neomenisci sections revealed regeneration of fibrocartilage. Type Ⅰ collagen in the neomenisci was also proved similar to normal meniscal tissue by immunohistochemical analysis and Sirius scarlet trinitrophenol staining. Articular cartilage degeneration was observed 8 weeks after implantation. It was less severe as compared with that in total meniscectomy controls and no further degeneration was observed at 18 weeks. At that time, the regenerated neomenisci strongly resembled normal meniscal fibrocartilage in gross and histological appearance, and its mechanical property was also close to that of normal meniscus. Conclusions: The present study demonstrates the feasibility of tissue-engineering a whole meniscal structure in total meniscectomy rabbit models using biodegradable PHBV scaffolds together with cultured allogeneic meniscal cells. Cartilage degeneration is decreased. But long-term in vivo investigations on the histological structure and cartilage degeneration of the neomenisci regenerated by this method are still necessary to determine the clinical potential of this tissue engineering avenue.

Abstract：Objective: To evaluate the clinical and radiological outcome of anterior vascularized bone graft in the treatment of primitive nonunion of the scaphoid. Methods: This is a retrospective study of 26 scaphoid nonunion cases treated by this technique between 2004 and 2009. The mean age was 38 years. Nonunion was of types ⅡA and ⅡB according to the Alnot's classification and only one case showed a proximal pole necrosis (type Ⅳ). The fixation was ensured by K-wire. The mean immobilization period was 9 weeks. Results: At mean 19 months follow-up, the bone union rate was 88.5%. Failure was noted in three cases. No significant complications secondary to this technique were observed. The mobility in extension and flexion had an average recovery of 18°. Nineteen patients (73%) were free of pain, and the others had occasional pain Conclusions: It is a meticulous surgical technique that provides better union rates than those of conventional scaphoid graft. This technique is first adopted in cases of failure of conventional grafts in the treatment of scaphoid nonunion but the encouraging results suggest expanding indications to primitive nonunion.

Abstract：Objective: To assess the outcome of immediate plate osteosynthesis via application of antibiotic impregnated collagen fleeces (gentamicin-collagen and antibiotic sponge) which gradually release antibiotic locally in the surgical treatment of open fractures presented to us 6 hours after injury. Methods: All cases were treated in our tertiary level trauma center and teaching hospital including 35 patients with open fractures who were treated by immediate open reduction and plate fixation from January 2008 to August 2010. Among them, 31 patients were available for adequate follow-up and assessment. All fractures were treated by irrigation and debridement, immediate open reduction and plate fixation along with placement of antibiotic-releasing collagen fleeces around the plate just before closure of wound. Patients were assessed to determine postoperative infection, delayed union or nonunion and development of other postoperative complications. It was hypothesized that immediate plate osteosynthesis after thorough debridement and local antibiotics would give safe and acceptable clinical results in treatment of open fractures. Results: The 31 patients with adequate final follow-up were assessed at a mean time of 40 weeks (15-160 weeks). Most fractures united primarily in an acceptable time period according to area of involvement. Local wound complications (superficial infection and skin loss) were found in 3 patients (9.67%). Deep infection was noted in 2 patients (6.45%). None of these patients needed implant removal and both fractures united in due time. Delayed union was noted in 5 patients (16.13%). No patient progressed to nonunion or implant failure in long term follow-up. Excessive scarring was developed in 2 patients (6.45%). Conclusions: Immediate plate osteosynthesis after adequate debridement and placement of collagen film eluting antibiotics locally produces excellent results regarding bone union and absence of deep infections and is a safe technique in the management of open bone injuries. These sponges can be used easily with any form of internal fixation and there is no need of second surgery for the removal of these antibiotic carriers since they are bioabsorbable. Local antibiotic-impregnated collagen sponges along with systemic antibiotics for 3 to 5 days offer promising results in open fracture management.

Abstract：Objective: To explore the therapeutic effect of osteogenically induced adipose-derived stem cells (ADSCs) on vascular deprivation-induced osteonecrosis of the femoral head (ONFH) in rabbit model. Methods: Vascular deprivation-induced ONFH was established by intramuscular injection of methylprednisolone, and vascular occlusion of the capital femoral epiphysis by electrocoagulation in adult New Zealand white rabbits. Eight weeks after the establishment of vascular deprivation-induced ONFH, animals were randomly divided into three equal groups. In Group A (control), no therapy was given. In Group B, core decompression was performed by drilling a hole (1.2 mm in diameter) from the outer cortex 2.5 cm distal to the proximal end of the greater trochanter. In Group C, 1 ×107 osteogenically induced ADSCs were resuspended in 0.5 ml PBS, and then injected directly into the femoral head. Femoral head specimens were obtained at postoperative 8 weeks. The bone formation and three-dimensional microstructure of the femoral head was evaluated by micro-computed tomography scans (μ-CT). Immunohistochemical analysis was performed to detect the expression of osteocalcin. Angiogenesis and repair of the femoral head were observed histologically. Results: In trabecular bone at the proximal femur region, the trabecular volume was higher in Group C (130.70 mm3± 4.33 mm3) than that in Groups A (101.07 mm3±7.76 mm3) and B (107.89 mm3±8.68 mm3, P＜0.01). Bone volume was significantly increased in Group C (40.09 mm3±6.35 mm3) than in Groups A (29.65 mm3±4.61 mm3) and B (31.80 mm3± 4.01 mm3, P＜0.01). The trabecular number was higher in Groups C (1.58±0.25) than other two groups (1.15±0.18, 1.16± 0.21, P＜0.01). Bone mineral density showed statistically significant difference between Groups C and A or B (375.38± 23.06) mg HA/ccm, vs (313.73 ±19.30) mg HA/ccm and (316.09± 16.45) mg HA/ccm, P<0.01). Histological examination indicated that there was more new bone formation in Group C than in other groups. Conclusion: Treatment with autologous osteogenically induced ADSCs transplantation results in an enhanced osteogenesis and microstructure of the vascular deprivation-induced osteonecrosis in rabbits.

Abstract：Objective: Monteggia fracture dislocation equivalent, though already described by Bado, is still an unclassified entity. We aimed to retrospectively analyze 18 cases of Monteggia variants and discuss the injury mechanisms, management, and outcome along with a re view of the literature. Methods: A retrospective record of Monteggia fracture dislocation (2003-2008) was reviewed from medical record department of our institute. Classic Monteggia fracture dislocation, children below 12 years or adults over 50 years, as well as open grade Ⅱ & Ⅲ cases were excluded from this study. Monteggia variant inclusion criteria included fracture of the proximal ulna together with a fracture of the radial head or neck and skeletal maturity. Totally 26 patients were identified with Monteggia variants and 18 were available for follow-up, including 11 males and 7 females with the mean age of 35 years. The ulna fracture was treated by compression plating along with tension band wiring. Radial head/neck was reconstructed in 12 patients while excised in 6 patients. Results: Follow-up ranged from 1 -4 years, mean 2.6 years. Patients were assessed clinicoradiologically. Mayo Elbow Performance Score was employed to assess the outcomes. At final follow-up, the results were excellent in 10 patients, good in 4, fair in 2 and poor in 2. Mean range of motion of the elbow was 20°, 116°, 50° and 55° for extension, flexion, pronation and supination, respectively. Two patients had complications in the form of heterotopic ossification and stiffness of the elbow. One nonunion ulna, primarily treated by tension band wiring, was managed by refixation with locking reconstruction plate and bone grafting. Bone grafting was only required in this patient for nonunion. Another patient had implants removed on his request. The results in our series closely correlated with extent of intraarticular damage, coronoid fracture and comminuted fractures. Conclusions: Monteggia fracture dislocation equivalents are rare injuries and pre-surgery recognition by radiographs and 3-D CT helps make optimal plan. The poor results usually relate to intraarticular damage, coronoid fractures and comminution of the ulna and radial head fractures.

Abstract：Objective: To evaluate the femoral head perfusion and to predict the traumatic avascular necrosis (AVN) of the femoral head by single photon emission computerized tomography and computerized tomography (SPECT/CT). Methods: Totally 18 adult beagle dogs were divided randomly into three equal-sized (n=6) groups. Subsequently different degrees of ischemia model were developed by destroying blood vessels of the femoral head. The left hip received sham operation as normal control and the right hip underwent blood interruption. In Group A, the ligamentum teres was cut off. In Group B, the marrow cavity of the right femoral neck was destroyed while in Group C, the soft tissues at the base of the femoral neck were stripped in addition to the resection of the ligamentum teres and destruction of the marrow cavity. Three hours after surgery, SPECT/ CT was performed. Laser Doppler Flowmetry (LDF) measurements were also obtained at three different time points (before operation, immediately and three hours after operation) in order to assess the change process of blood supply to the femoral head. Results: SPECT/CT showed no significant difference in the radionuclide uptake between the right and left femoral heads in Group A (t=-0.09, P=0.94) and Group B (t= 0.52, P=0.62). However, in Group C, it was 261 ±62 for the right femoral head, only 12% of that in the left femoral head. LDF measurements indicated that the femoral head perfusion was decreased from (45.0±3.3) PU to (39.1±3.7) PU in Group A, from (44.0±2.7) PU to (34.3±2.6) PU in Group B, and from (47.3 ±2.1) PU to (4.96±0.6) PU in Group C immediately after operation. However, the perfusion was restored and returned to normal values three hours after operation except in Group C. Conclusion: SPECT/CT could assess the perfusion of the femoral head semiquantitatively, which might be useful in predicting the development of traumatic AVN。

Abstract：Objective: To investigate the efficacy of the locking internal fixator (LIF), which includes the locking compression plate (LCP) and the less invasive stable system (LISS), in the proximal and distal tibial fractures. Methods: We did a retrospective study on a total of 98 patients with either proximal or distal tibial fractures from January 2003 to January 2007, who had received the operation with LIF by the minimally invasive plate osteosynthesis (MIPO) technique. The data consisted of 43 proximal tibial fractures (type AO41C3) and 55 distal tibial fractures (type AO43C3). Results: No complications were observed in all patients after operation. The mean healing time was 8.4 months (range 5-14 months). Only two cases of delayed union occurred at postoperative 10 months. No infections were reported after the definitive surgery even in the cases of open fractures. All patients reached a full range of motion at postoperative 6 to 9 months and regained the normal functions of knee and ankle joints. Conclusion: Using LIF in MIPO technique is a reliable approach towards the proximal and distal tibial fractures that are not suitable for intramedullary nailing。

Abstract：Objective: To investigate the efficacy of buried purse-string suture in the treatment of mallet finger deformities. Methods: From February 2009 to February 2010, 12 patients with closed non-fracture mallet fingers were treated by buried purse-string suture. The rupture tendons were sutured by purse-string suture with an atraumatic needle, and the knots were buried under subcutaneous tissue. External fixator was used at the extension position of the finger every night within three weeks after operation. Results: All patients were followed up for 6-12 months, mean 7 months. According to the Patel's evaluation criteria, 2 cases (17%) obtained excellent results, 7 good (58%), 2 fair (17%) and 1 poor (8%). The overall rate of the cases with excellent and good outcomes was 75%. Conclusion: Buried purse-string suture is an easy and effective way to treat mallet finger deformities, with no serious postoperative complications or no need for reoperation.

Abstract：We reported a 23-year-old man who was involved in a high-speed motorcycle accident. He sustained a closed fracture at the right distal femur. The primary fracture happened on February 2008. He underwent open reduction and internal fixation with cloverleaf plate. And one hundred days after the surgery, the proximal screws were pulled-out, but the bone union was not achieved. Treat ment consisted of exchanging the cloverleaf plate with a locking compression plate and using an auto-iliac bone graft to fill the nonunion gap. In July 2009, the patient had a sharp pain in the right lower limb. The X-ray revealed that the plate implanted last year was broken, causing a nonunion at the fracture site. Immediately the plate and screws were removed and an intramedullary nail was inserted reversely from the distal femur as well as a 7 cm long bone from the right fibula was extracted and longitudinally split into two pieces to construct cortical bone plates. Then we placed them laterally and medially to fracture site, drilled two holes respectively, and fastened them with suture. We carried on auto-iliac bone grafting with the nonunion bone grafts. The follow-up at 15 months after operation showed that the treatment was successful, X-ray confirmed that there was no rotation and no angular or short deformity. We briefly reviewed the literature regarding such an unusual presentation and discussed in details the possible etiology and the advantages of autologous double-strut fibular grafts to cope with such an intractable situation.

Abstract：A case of a 50-year-old pedestrian who was hit by a bike and suffered fractures of both bones of his right leg was presented. Complete clinical and radiographic assessment showed double segmental fractures of the tibia and multisegmental fractures of the fibula. Review of the literature revealed that this fracture pattern was unique and only a single case was reported so far. Moreover, we discussed the possible mechanisms which can lead to such an injury. We also discussed the management of segmental tibial fracture and the difficulties encountered with them. This case was managed by modern osteosynthesis tech nique with a pleasing outcome.

Abstract：Both severed legs were replanted in a 41-year-old man. Bilateral tibia and fibula were shortened by 4 cm equally. Tibial fixation was performed with reconstruction plate. Four weeks after the replantation, active and passive exercises were initiated in both of the knee joints. Four months after surgery, the patient was capable of walking independently for 20-30 m without the aid of crutches. After 28 months' follow-up, plantar sensitivity was defined as S3. This patient was satisfactory with the cosmetic and functional results.

Abstract：Intra-articular coronal fractures (Hoffas fractures) of distal femur are rare. Although bicondylar involvement in these fractures has been reported in the literature in association with high velocity traumata, the occurrence of these fractures involving extensor mechanism rupture and avulsion of ipsilateral tibial spine is extremely rare. To our acquaintance, such a fracture pattern has not yet been reported in the literature so far. In this article, we report one such case and discuss the importance of early diagnosis and prompt internal fixation in the management of such cases. We believe that these rare combinations of injuries should be treated aggressively by early open reduction and anatomic rigid internal fixation in order toachieve good recovery of function.