ObjectiveTo summarize the current researches and progress on experimental animal models of avascular necrosis of the femoral head. MethodsDomestic and international literature concerning experimental animal models of avascular necrosis of the femoral head was reviewed and analyzed. ResultsThe methods to prepare the experimental animal models of avascular necrosis of the femoral head can be mainly concluded as traumatic methods (including surgical, physical, and chemical insult), and non-traumatic methods (including steroid, lipopolysaccharide, steroid combined with lipopolysaccharide, steroid combined with horse serum, etc). Each method has both merits and demerits, yet no ideal methods have been developed. ConclusionThere are many methods to prepare the experimental animal models of avascular necrosis of the femoral head, but proper model should be selected based on the aim of research. The establishment of ideal experimental animal models needs further research in future.
ObjectiveTo investigate the effectiveness of digital technology in repairing wounds of the hand and foot with anterolateral thigh flap. MethodsBetween September 2013 and September 2014, 16 cases of wounds of the hand and foot were treated with the anterolateral thigh flap. There were 10 males and 6 females, with an average age of 31 years (range, 20-52 years). The causes included traffic accident injury in 8 cases, crushing injury by machine in 6 cases, burning injury in 1 case, and animal biting injury in 1 case. The locations of soft tissue defect were the dorsum of the foot in 5 cases, the ankle in 4 cases, the planta pedis in 1 case, and the hand and forearm in 6 cases. The time was 2 hours to 45 days from injury to hospitalization (mean, 14.3 days). All defects were associated with exposure of bone and tendon. The size of wound was from 9.0 cm×4.0 cm to 29.0 cm×8.5 cm. CT angiography (CTA) was performed before operation, and the appropriate perforator as well as the donor site was selected. Then the Mimics15.0 software was used to reconstruct the data of CTA so as to locate the main perforators, design the three-dimensional models of the anterolateral thigh flap, and simulate operation. The flap was obtained according to preoperative plan during operation. The size of flaps varied from 11 cm×5 cm to 31 cm×10 cm. The donor sites were sutured directly in 14 cases and were repaired by free skin graft in 2 cases. ResultsThe lateral femoral circumflex artery identified by Mimics15.0 software before operation, as well as the starting position of its descending branch, the blood vessel diameter at start site, vascular distribution, the maximum cutting length of the vascular pedicle were consistent with the actual observation during operation. All flaps were harvested and were used to repair defect smoothly. Vascular crisis occurred in 1 flap after operation, and the other flaps survived successfully. The wounds and the incisions obtained healing by first intention, and grafted skin survived completely. All cases were followed up 6-17 months (mean, 9 months). Fifteen flaps had good shape;but a second-stage operation was performed to make the flap thinner in 1 case. At last follow-up, the results were excellent in 3 cases, good in 2 cases, and fair in 1 case according to total active motion (TAM) in 6 cases of hand and forearm injury;the results were excellent in 5 cases, good in 3 cases, and fair in 2 cases according to American Orthopaedic Foot and Ankle Society (AOFAS) in 10 cases of foot injury. The total excellent and good rate was 81.25%. ConclusionThe preoperative individualization design of the flap can be realized through CTA digital technology and Mimics15.0 software;it can reduce the operation risk.
ObjectiveTo investigate the feasibility and early effectiveness to treat osteonecrosis of the femoral head (ONFH) with pedicled iliac bone graft assisted by individual digital design and three dimensional (3D) printed navigation templates. MethodsBetween February and June 2014, 15 patients (24 hips) with ONFH underwent pedicled iliac bone graft assisted by individual digital design and 3D printed navigation templates. There were 11 males (17 hips) and 4 females (7 hips) with a mean age of 38 years (range, 18-56 years) and a mean disease duration of 7.5 months (range, 1-24 months); the left hip was involved in 2 cases, the right hip in 4 cases, and both hips in 9 cases. There were 7 cases (12 hips) of steroid-induced ONFH, 5 cases (8 hips) of alcohol-induced ONFH, 1 case (1 hip) of traumatic ONFH, and 2 cases (3 hips) of idiopathic ONFH. The preoperative Harris score was 56.60±6.97. According to Association Research Circulation Osseous (ARCO) staging system, 5 hips were classified as stage IIB, 8 hips as stage IIC, 6 hips as stage IIIB, and 5 hips as stage IIIC. The navigation templates were designed and printed to assist accurate location and debridement of necrosis area according to preoperative CT scanning at the beginning of pedicled iliac bone grafting procedure. ResultsThe mean operation time was 135 minutes (range, 120-160 minutes), mean amount of bleeding was 255 mL (range, 200-300 mL). All the wounds healed primarily, no complication of deep vein thrombosis or infection was observed. All patients were followed up 12-16 months (mean, 14 months). The location of necrosis area was in accordance with preoperative design, which was removed completely without penetration of joint surface, pedicled iliac bone graft was performed at the right site according to postoperative imaging examination. Radiographically, graft fusion was achieved at 2.7 months (range, 2-3 months) in all patients. All the hips had no collapse during follow-up. Hip pain was relieved, and range of motion was improved. The Harris score was significantly improved to 89.53±5.83 at last follow-up (t=14.319, P=0.000). The results were excellent in 12 hips, good in 10 hips, and fair in 2 hips according to Harris score standard. ConclusionPedicled iliac bone graft assisted by individual digital design and 3D printed navigation templates for treatment of adult ONFH has the advantages of accurate location and complete debridement of necrosis area, so satisfactory results can be obtained.