Objective To study and compare boneforming mechanismafter compound of autologous periosteum-wrapped tendon with spongiosa homogenate and other implants in articular cavity, and to explore the possibility of the compound as a substitute for the lunate in Kienbock’s disease.Methods Forty-five New Zealand white rabbits were randomly divided into three groups: periosteum group(group A, n=15), composite group(group B, n=15), and control group(group C, n=15). The three sorts of implants were placed into articular cavity of the knee respectively. The changes of bone formation and bone morphogenetic protein (BMP) distribution of the implants were examined under optical microscope with HE and immunohistochemical staining and measured by CT 3, 6 and 9 weeks after operation.Results The result of BMP staining was negative after 3 weeks and positive in new cartilage cells after 9 weeks in group A. The positive BMP staining was observed in group B after 3 weeks and 9 weeks, which mainly distributed in new bone cells and cartilage cells. And negative BMP staining was observed every stage in groupC. The quantitative CT bone mineral density (BMD) values of 3 implants were analyzed, the difference was significant between the groups (Plt;0.01), except that between groups A and C in the 3rd week (Pgt;0.05). Conclusion The above results demonstrated that the compound of autologous periosteum-wrapped tendon and spongiosa homogenate can produce bone and cartilage massively under the induction of periosteum and bone-forming factors such as BMP in spongiosa homogenate and the compound can be used as a substitute for the lunate.
ObjectiveTo discuss the imaging manifestations of ulnar impaction syndrome, and to evaluate the diagnostic value of MR imaging. MethodsThe clinical data of 18 patients with clinical standard-proved ulnar impaction syndrome between January 2010 and June 2013 were retrospectively reviewed. ResultsSeventeen cases were diagnosed as ulna positive variation (94.6%), and the range of ulnar variance was 1.5 to 3.8 mm and the average ulnar variance was 2.6 mm. Neutral variance was found in one case. Fourteen cases had avascular necrosis or bone sclerosis of semilunar bone, and avascular necrosis or bone sclerosis of the triquetrum and ulnar was presented in 12 cases and 3 cases respectively on X-ray detection. CT scan showed that 16 cases of semilunar bone abnormalities (6 with ischemic necrosis), triquetrum osteonecrosis in 4 cases, and both necrosis of semilunar bone and triquetrum in 3 cases. On MRI, all cases had different degrees of damage, degeneration of semilunar bone, triquetrum, ulnar and triangular fibocartilage complex (ulnar side of the proximal end of the lunate in 18, radial side of the triquetrum in 17, distal joint surface of ulnar in 12, and triangular fibocartilage complex in 15). In the early stage, lesions were presented as edema of bone marrow and followed as different sizes of cystic change. Articular surface was collapsed later. ConclusionUlnar positive variance has important reference value in the diagnosis of ulnar impaction syndrome. MRI can show the early change of ulnar impaction syndrome, and provide reliable decision basis for clinical diagnosis and treatment.