Periosteal and perichondral grafting in reconstructive surgery.

Periosteum consists of multipotent mesodermal cells, and the influence of the environment on differentiation of cells of free periosteal grafts has been demonstrated in experimental studies. Periosteum has the capacity to form all varieties of connective tissue. The periosteum has osteogenic capacity, but it can also be used to promote cartilage formation in a chondrotrophic environment. Free periosteal grafts transplanted to the completely chondrectomized articular surfaces of patellae in experimental animals differentiated into cartilage. Joint motion appeared to be one of the chondrogenesis-promoting factors. The authors are optimistic about the potential clinical results with these types of grafts. Also, periosteal resurfacing of the metatarsal head was found to be suitable in the treatment of hallux rigidus and Freiberg's disease. Findings in growing rabbits showed that spinal fusion can be achieved with free periosteal grafts. This technique has been used to treat lumbar lytic spondylolisthesis in young patients, and the method produced clinical and radiologic results that were comparable with those obtained using bone transplants. This work indicates that some of the adverse effects of lumbar spinal fusion (e.g., postoperative spinal stenosis) can be avoided by using osteoperiosteal fusion. Also, periosteal grafting has proved useful in the treatment of thoracolumbar scoliosis. Free periosteal grafting has been used to treat congenital clefts of the maxilla and tracheal cartilage defects.

Reconstruction of the patellar articulation with periosteal grafts. 4-year follow-up of 13 cases.

Reconstruction of the damaged articular surface of the patellar articulation with free periosteal grafts was performed in 13 patients who had not responded to previous treatment. After an average of 4 years, a good result was obtained in 8 patients and a fair result in 4 others. Only 1 patient, a 55-year-old man with severe patellar arthrosis, continued to have disabling pain.

Effect of diffusion chamber pore size on differentiation and proliferation of periosteal cells. An experimental study.

The influence of the pore size of Nucleopore diffusion-chamber filters on the rate of proliferation and differentiation of periosteal cells in muscle was studied in 44 growing rabbits. Periosteal grafts were placed in chambers (16-19 in each experimental group) sealed with filters with a pore size of 0.4, 0.6, 0.8, 1.0, or 2.0 micron. Each chamber was implanted into the paraspinal muscle of the rabbit, where it remained for 16 weeks. The osteochondrogenic activity of the graft grew linearly when the pore size increased from 0.4 to 1.0 micron. In the chambers with a pore size of 2.0 micron, both bone and cartilage were found in only one chamber. Bone and cartilage were not found outside any of the chambers. The present results showed that the pore size of the filters significantly affected the ability of the periosteal graft to form bone and cartilage.

Differentiation of periosteal cells in muscle. An experimental study using the diffusion chamber method.

The osteo-chondrogenic capacity of the undifferentiated mesenchymal cells of the periosteum has been made use of in clinical reconstructive surgery. In the present investigation we studied the osteo-chondrogenic potency of free periosteal transplants in muscle using the diffusion chamber method. A total of 42 experimental and seven control rabbits aged four to six weeks were operated on. Periosteum was obtained from the anterior aspect of the left tibial bone by stripping. The grafts were placed in Nucleopore diffusion chambers with a pore size of 0.4 micron. The chambers were implanted in the anterior tibial and paraspinal muscles of the rabbit. Osteogenesis began after the second postoperative week and increased up to the 5-6 week interval when a plateau phase was reached. Chondrogenesis, which also began after the second postoperative week, reached two plateau phases; the first observed at 4-8 weeks and the second at 12-16 weeks. Neither bone nor cartilage formation could be observed outside the chambers. In the semi-open control chambers with only one end sealed, bone formed within the chamber as early as two weeks after transplantation and grew out into the adjacent connective tissue of muscle. It is noteworthy that the periosteal transplant retained its osteochondrogenic properties even when isolated in the diffusion chamber. The young age of the donor animals might have contributed to our findings.

Behaviour of cancellous bone graft with and without periosteal isolation in striated muscle. An experimental study.

The capacity of the periosteum to inhibit resorption of cancellous bone grafts into muscle was investigated in 34 four- to six-week-old rabbits. In 17 experiments the periosteum was wrapped around the grafts with the cambium layer facing the bone, and in seven experiments with the cambium layer facing the muscle. In the control group of 10 experiments there was no periosteal wrapping around the bone grafts. In Series 1 with the cambium layer of the periosteum facing the bone, after 20 weeks a tubular bone with Haversian system and bone marrow was seen. The transplants were surrounded by normal-looking periosteum. Bone formation from the periosteum occurred through enchondral ossification. Inductive bone growth was observed from the cancellous graft. In Series 2 with the cambium layer facing the surrounding muscle tissue, after 20 weeks two laminar bone blocks with periosteum in between and surrounding each block was observed. In the control series without periosteal covering, after 20 weeks only fibrous tissue remained in the transplantation site. It is obvious that periosteal isolation of cancellous bone grafts inhibits their resorption when transplanted into muscle in young animals.

Free fat transplant prevents osseous reunion of skull defects. A new approach in the treatment of craniosynostosis.

Free fat tissue transplant to correct premature epiphyseal fusion of long bones has been successfully used to prevent re-ossification after bone bridge resection. In the present study we have applied this principle in the prevention of osseous reunion of the bone defect in the calvaria of the rabbit. In two-week-old animals standard bone defects were made on both sides of the sagittal suture to the temporal bone. The dura was left intact. On the right side a free autogenous fat transplant was placed to fill the bone defect. On the left side the control defect was left without fat interposition. The skull defects were examined postoperatively at three weeks, three months, and eight months. The control defects reossified within three weeks. The bone defects with fat tissue transplant were found to be open and of original size at eight months postoperatively. On the transplanted side histological examination revealed living fat cells filling the gap. Osteogenesis was inhibited and reunion of the bone edges was prevented. All the control bone defects were filled by lamellar bone. The use of free fat tissue transplant can be a useful alternative, serving as a biological interposition material in the surgical treatment of craniosynostosis.

Reconstruction of patellar cartilage defects with free periosteal grafts. An experimental study.

The osteo-chondrogenic potential of free periosteal grafts was investigated within the knee joint in 26 rabbits aged four to six weeks. A total of 36 knee joints were operated on. The grafts were stripped from the medial side of the right tibia and sutured on the articular surface of the patella, from which the cartilage had been totally excised to the subchondral bone. In 16 knees the graft was sutured with the cambium layer towards the subchondral bone and in eight knees the fibrous layer faced the bone. In the control group of twelve knees the patellar articular cartilages were excised and no periosteal transplant was grafted to the patellar articular surface. In the transplantation group cartilage formation could be seen already one week after the operation. There were no marked differences between the series with the cambium layer facing the subchondral bone or the group with the fibrous layer facing the bone. At 20 weeks the hypertrophied cartilage had thinned and resembled normal joint cartilage. In the control group the histological picture resembled osteoarthritis.