Objective To investigate the factors that affect platelet-rich plasma (PRP) in promoting bone regeneration and repairing. Methods Recent l iterature was reviewed, concerning the preparations of PRP, physiological mechanism and the latest appl ications in orthopedic field. Results PRP, the concentrated body of autologous platelet, was rich in platelets and was the source of autologous growth factors. Many studies had shown that PRP played an important role in promoting bone regeneration and repairing. However, a few experimental results contradicted this point. The reason might be that the biological properties of PRP were influenced by various factors, such as workmanship, vector, activation schemes, working concentration, individual difference. Conclusion The concentration and qual ity of platelet and other related factorsof PRP affect the rel iabil ity of the results and conclusions. So an efficient and stable production method of PRP should beestabl ished.
Objective The tendon-bone heal ing is the key point to ensure the success of the anterior cruciate l igament (ACL) reconstruction. To observe the histological change in the tendon-bone heal ing after ACL reconstruction by different concentrations of platelet-rich plasma (PRP) combined with deproteinized bone (DPB) of calf as bone tunnel infill ing and to investigate the active effect of the complex on tendon-bone heal ing and to define the optimal concentration of PRP. Methods Eight mL blood was drawn from central artery of New Zealand rabbit ears; PRP was prepared by Landesbergmethod, and l iquid supernatant was used as thinner to prepare different concentrations of PRP (30%, 60%, and 100%). Fresh osteoepiphysis spongy bone was harvested from lower end of femur of newborn calf to prepare DPB by way of 30% H2O2 and ether alternating soaking for 24 hours continuous 6 times. DPB was soaked in different concentrations of PRP and mixed with activator to prepare the PRP/DPB complex. A total of 54 New Zealand white rabbits, aging 8-12 months, weighing (2.5 ± 0.4) kg, were divided randomly into 3 groups: group A (30%PRP/DPB complex, n=18), group B (60%PRP/DPB complex, n=18), and group C (100%PRP/DPB complex, n=18). The legs of the rabbits were randomly divided into experimental side and the control side; ACL was reconstructed by semitendinosus and PRP/DPB complex in bone tunnel in the experimental side, and only by semitendinosus in the control side. The general conditions of the rabbits were observed postoperatively and HE staining was used to observe the tendon-bone heal ing, then I-IV levels of semi-quantitative analysis of the tendon-bone heal ing were evaluated according to Demirag standard at 3, 6, and 12 weeks. Results General observation: Synovial fluid sl ightly increased in the specimens and no bony tissue was found in inner of femoral tunnel at 3 weeks; there was no synovial fluid in all the specimens and scar tissue was discovered in inner of femoral tunnel at 6 weeks; and there was no synovial fluid and the tendons became tighter with fibrous tissue at 12 weeks. Histological observation: New granulation tissue formed in the tendon-bone interface of group A experimental sides at 3 weeks; there was various widths of Sharpey type textile fiber in the tendon-bone interface at 6 weeks; Sharpey type textile fiber arranged regularly, which formed an irregular and blur “tidal l ine” at 12 weeks. Group B experimental sides were better than any other group at 3, 6, and 12 weeks; chondrocyte-l ike arranged regularly in the tendonboneinterface at 3 weeks; the number of chondrocyte-l ike per unit area was more than that of the other groups at 6 weeks;and chondrocyte-l ike prol iferated and matured in the tendon-bone interface, Sharpey type textile fiber became tighter andordered. Group C experimental sides were similar to both sides of group A at 3 weeks, however, the prol iferation of relatively mature dense connective tissue was worse than that of other groups at 6 and 12 weeks. According to Demirag grading, there were significant differences in tendon-bone heal ing between the experimental sides and the control sides of group B at 3 and 6 weeks, and between group B experimental sides and group C experimental sides at 12 weeks (P lt; 0.05). Conclusion The mixture of PRP/PRP has good biocompatibil ity and bone induction, so it can enhance tendon-bone heal ing after ACL reconstruction when the concentration of PRP is 60%.
Objective To investigate the efficacy of double-plating fixation via U-shaped incision in the treatment of type C3.3 distal femoral fractures. Methods From July 2006 to February 2009, 11 cases of type C3.3 distal femoral fractures were treated, including 5 open fractures and 6 closed fractures. Among them, there were 7 males and 4 females with an averageage of 43 years (range, 27-55 years). The locations were left side in 6 cases and right side in 5 cases. Fracture was caused by traffic accident in 8 cases and fall ing from height in 3 cases. The time from injury to hospital ization was 30 minutes to 7 days. After bone traction for 3 to 8 days, the operations were performed by double-plating fixation via U-shaped incision, and autograft of il iac bone or allogeneic bone grafting. Results The average time of operation was 128 minutes (range, 105-150 minutes). The average blood loss during operation was 344 mL (range, 290-380 mL). Shallow local skin flap necrosis occurred in 2 cases, and incision healed by first intention in others patients. All patients were followed up 22 months on average (range, 12-36 months). The bone union was achieved within 3-6 months (4.4 months on average). No implant loosening or refracture was found. According to Merchan et al criteria for knee joint function evaluation, the results were excellent in 4 cases, good in 5 cases, fair in 1 case, and poor in 1 case at last follow-up; the excellent and good rate was 81.8%. Conclusion The double-plating fixation via U-shaped incision has the advantages of better exposure, great convenience to manipulation, anatomical reduction, and rigid fixation. It provides an effective treatment for type C3.3 distal femoral fracture. However, its operation indications and operating instructions should be strictly followed.
Objective To design an open shape memory alloy artificial vertebral body that can be used to reconstruct the vertebral body in spine diseases, such as thoracic-lumbar spine tumors, burst fracture of the vertebrae, kyphosis and scol iosis, and to evaluate the biomechanical stabil ity of lumbar functional segment unit after insertion with the shape memoryalloy artificial vertebral body. Methods The open shape memory alloy artificial vertebral body with nickel-titanium (NiTi)alloy was made. Eight fresh spine specimens (T14-L5) from normal adult porcine were used to detect the range of motion (ROM) in 4 models and were divided into 4 groups: intact vertebrae served as group A; pedicle screw fixation of T15, L1, L3, and L4 was given in group B; after total resection of L2, it was reconstructed by open shape memory alloy artificial vertebral body combined with pedicle screw fixation of T15, L1, L3, and L4 in group C; and after total resection of L2, it was reconstructed by titanium cage vertebral body combined with pedicle screw fixation of T15, L1, L3, and L4 in group D. The three-dimensional ROM of flexion, extension, left/right lateral bending, and left/right rotation in T15-L1, L1-3, and L3,4 segments were detected in turn by the spinal three-dimensional test machine MTS-858 (load 0-8 N•m). Results Compared with group A, groups B, C, and D had good stabil ity in flexion, extension, left/right lateral bending, and left/right rotation, showing significant differences (P lt; 0.05). There was no significant difference in the degree of each motion between group B and group C (P gt; 0.05). Group C had less degree of motion in T15-L1 and L3,4 segments than group D, showing significant differences (P lt; 0.05), but there was no significant difference in L1-3 segment (P gt; 0.05). Conclusion The open shape memory alloy artificial vertebral body has a reasonable structure and good biomechanical stabil ity, it can be used to stabil ize the spinal segment with pedicle screw fixation.
Objective To evaluate and compare the outcomes of simple closed reduction, selective fragment excision after closed reduction, and emergency fragment excision and reduction in the treatment of Pipkin type I fracture of femoral head associated with posterior dislocation of the hip. Methods Between January 2002 and January 2008, 24 patients with Pipkin type I fracture of the femoral head associated with posterior dislocation of the hip were treated with simple closed reduction (closed reduction group, n=8), with selective fragment excision after closed reduction (selective operation group, n=8), and with emergency fragment excision and reduction (emergency operation group, n=8). In the closed reduction group, there were 6 males and 2 females with an average age of 37.6 years (range, 19-56 years); injuries were caused by traffic accident in 6 cases, by fall ing from height in 1 case, and by crushing in 1 case with a mean disease duration of 3.1 hours (range, 1.0-7.5 hours); and the interval from injury to reduction was (4.00 ± 2.14) hours. In the selective operation group, there were 7 males and 1 female with an average age of 37.3 years (range, 21-59 years); injuries were caused by traffic accident in 7 cases and by fall ing from height in 1 case with a mean disease duration of 3.2 hours (range, 1.0-6.0 hours); and the interval from injury to reduction was (3.90 ± 1.47) hours. In the emergency operation group, there were 5 males and 3 females with an average age of 35.5 years (range, 20-58 years); injuries were caused by traffic accident in 5 cases, by fall ing from height in 1 case, and by crushing in 2 cases with a mean disease duration of 3.3 hours (range, 1.5-6.5 hours); and the interval from injury to open reduction was (5.10 ± 2.04) hours. There was no significant difference in the age, gender, disease duration, and interval from injury to reduction among 3 groups (P gt; 0.05). Results All wounds in selective operation group and emergency operation group healed primarily. All the patients were followed up 24 to 58 months (mean, 38.7 months). According to Thompson-Epstein system, the excellent and good rates were 50.0% (4/8) in the closed reduction group, 87.5% (7/8) in the selective operation group, and 87.5% (7/8) in the emergency operation group at 24 months after operation, showing significant difference among 3 groups (χ2=9.803, P=0.020). Heterotopic ossification was found in 1 case (12.5%) of the closed reduction group, in 4 cases (50.0%) of the selective operation group, and in 4 cases (50.0%) of the emergency operation group, and avascular necrosis of femoral head was found in 2 cases (25.0%) of the closed reduction group; there was no significant difference in compl ications among 3 groups (P gt; 0.05). Conclusion The treatment of Smith-Petersen approach and fragment excision by selective operation or emergency operation has similar outcome, which are better than the treatment of simple closed reduction.