Objective To find out an effective technique torepair large segmental infected bony defect.Methods Calcium phosphate cement(CPC) incorporated with bone morphogenetic protein and gentamycin was embedded in the massive reconstituted bovine xenograft(MRBX), then CPC-MRBX was obtained after CPC’s solidification. In vivo test was applied to test the drug delivery capability of CPC-MRBX, in which it was implanted in the dorsal muscle pouch of 18 rabbits. The drug concentration of animal blood and surrounding soft tissue of the CPC-MRBX in the muscle pouch was measured 1, 2, 5, 10, 15, 20, 25, 30 and 35 d after operation, 2 rabbits each time. Large segmental infected femur defect in the rabbit model was created to test the repairing capability of CPC-MRBX. External fixation was done 1.5~2.0 cm above the knee, the most adjacent nail to fracture site was 0.5～0.8 cm away, and proper pressure was applied to the graft. In experimental group(n=25), the bony defect was replaced by CPC-MRBX, while in the control group(n=15) dissected bone block was re-implanted in original position. The animal was subjected to radiographic, histological examination at 4, 8, 16 and 24 weeks. The general condition was observed after the operation.Results CPC-MRBX was easily made under normal temperature and pressure. In viro drug delivery test showed that the drug concentration of the tissue remainedabove the minimal inhibitory concentration of staphylococcus 30 d after operation and no significant increase of blood drug concentration was observed. In experimental group, no adverse influence was observed. Four weeks after operation, the animal could bear load, bony callus around the graft was observed by X-ray, and abundant chondral tissues that grew into CPC-MRBX were observed by histological method. Eight weeks after operation, progressively increasing bony callus around the graft was observed, external fixation could be removed, normal function was restored, and CPC was degenerated dramatically while new bone tissues were growing. Sixteen weeks after the operation, more new bone tissues grew and CPC was degenerated furtherly while marrow tissues were taking shape. Twenty-four weeks after the operation, femur healed completely and CPC was degenerated completely. In the control group, the autograft remained unhealedon X-ray at 4 weeks, and osteomyelitis manifestation such as inflammatory cells infiltration and osteolysis was detected at 4 weeks. All the animals in the control group died before the 8th week, 4 of which showed positive hemoculture. Conclusion CPC-MRBX is readily available and can be applied to repairing large segmental infected bony defect.30 d after operation and no significant increase of blood drug concentration was observed. In experimental group, no adverse influence was observed. Four weeks after operation, the animal could bear load, bony callus around the graft was observed by X-ray, and abundant chondral tissues that grew into CPCMRBX were observed by histological method. Eight weeks after operation, progressively increasing bony callus around the graft was observed, external fixation could be removed, normal function was restored, and CPC was degenerated dramatically while new bone tissues were growing. Sixteen weeks after the operation, more new bone tissues grew and CPC was degenerated furtherly while marrow tissues were taking shape. Twenty-four weeks after the operation, femur healed completely and CPC was degenerated completely. In the control group, the autograft remained unhealedon X-ray at 4 weeks, and osteomyelitis manifestation such as inflammatory cells infiltration and osteolysis was detected at 4 weeks. All the animals in the control group died before the 8th week, 4 of which showed positive hemoculture.Conclusion CPC-MRBX is readily available and can be applied to repairing large segmental infected bony defect.
Objective To investigate the effect of homograft of marrow mesenchymal stem cells (MSCs) seeded onto poly-L-lactic acid (PLLA)/gelatin on repair of articular cartilage defects. Methods The MSCs derived from36 Qingzilan rabbits, aging 4 to 6 months and weighed 2.5-3.5 kg were cultured in vitroand seeded onto PLLA/gelatin. The MSCs/ PLLA/gelatin composite was cultured and transplanted into full thickness defects on intercondylar fossa. Thirty-six healthy Qingzilan rabbits were made models of cartilage defects in the intercondylar fossa. These rabbits were divided into 3 groups according to the repair materials with 12 in each group: group A, MSCs and PLLA/gelatin complex(MSCs/ PLLA/gelatin); group B, only PLLA/gelatin; and group C, nothing. At 4,8 and 12 weeks after operation, the gross, histological and immunohistochemical observations were made, and grading scales were evaluated. Results At 12 weeks after transplantation, defect was repaired and the structures of the cartilage surface and normal cartilage was in integrity. The defects in group A were repaired by the hylinelike tissue and defects in groups B and C were repaired by the fibrous tissues. Immunohistochemical staining showed that cells in the zones of repaired tissues were larger in size, arranged columnedly, riched in collagen Ⅱ matrix and integrated satisfactorily with native adjacent cartilages and subchondral bones in group A at 12 weeks postoperatively. In gross score, group A(2.75±0.89) was significantly better than group B (4.88±1.25) and group C (7.38±1.18) 12 weeks afteroperation, showing significant differences (P＜0.05); in histological score, group A (3.88±1.36) was better than group B (8.38±1.06) and group C (13.13±1.96), and group B was better than group C, showing significant differences (P＜0.05). Conclusion Transplantation of mesenchymal stem cells seeded onto PLLA/gelatin is a promising way for the treatment of cartilage defects.
Objective To investigate the clinical feasibility of different types of the saphenous neuro-veno-fascial cutaneous flaps. Methods From June 1996 to October 2002, 18 cases of skin defects in the knee and the lower part of the limb were treated with proximally(4 cases) or distally(11 cases) based pedicles of saphenous neuro-venofascial cutaneous flap or crossleg flap (3 cases)according to the site of defects . The sizes of the flaps ranged from 4 cm×5 cm to 9 cm×20 cm. Results The flaps survived completely in 17 cases, distal 1/5 of the flap necrosed partially in 1 case because of vein drainage disturbance. The colour and texture of flaps were excellent, the appearance and function were satisfactory after a follow up of 6-24 months.Conclusion The saphenous neuro-veno-fascial cutaneous flap is an idea flap in repairing skin defects of the knee, the leg, the ankle and the foot because it is easy to be designed and dissected and it has reliable blood supply and preserved main artery. The relationship between the septal perforating branches of the tibial posteriorartery and survival size of flap need to be investigated further.
Objective To investigate the outcome of repairing hand composite defects using pedicle osteocutaneous groin flap. Methods From February 1998 to May 2004, 33 cases of hand composite defects were repaired with pedicle osteocutaneous groin flap. There were 22 males and 11 females. The age was 19 to 54 years with an average of 243 years. The defect was caused by palmar penetrating injury in 17 cases, by dorsal hand crushing injury in 9 cases and by other injury in 7 cases. Twentythree cases complicated by metacarpal defect, 10 by phalanx defect. Thesize of skin defect was 3.5 cm×2.0 cm to 15.0 cm×10.0 cm, the size of bonedefect was 1.5 to 3.5 cm. After 3 to 7 days of primary debridement, defect was repaired by the pedicle osteocutaneous groin flap based on the superficial circumflex iliac vessels. The flap size was 4.0 cm×2.5 cm to 17.0 cm×11.0 cm. Results All the osteocutaneous flaps survived. During the 4 to 22 months follow-up postoperatively, thetexture, appearance and function of the flap were excellent and bone union was obtained in all cases after 7 to 9 weeks of operation.Conclusion The pedicle osteocutaneous groin flap is an ideal flap to repair the composite defect of the hand, with the benefit of simple procedure and reliable blood supply.