In order to define the changes of mechanical properties of bone tissue in the growing period, 90 rabbits' tibiae were loaded in 3-point bending. Emphasis was given to the accurate measurement of maximum angulation degrees within the limit of elastic deformation. Young's modulus of elasticity increased with increasing body weight, and the increments of bending stiffness were more prominent. In rabbits of low body weights, the tibiae absorbed more energy before fracture occurred and plastic deformation after fracture occurred more frequently. The mean values and standard deviations of the maximum angulation were 9.84±1.33 degree in Group 1 (range of body weight: 800–1200g), 7.55±0.85 degrees in Group 2 (range of BW: 1600–2000g), and 5.90±0.78 degrees in Group 3 (range of BW: 2400–2800g), These data may support that the allowable maximum angular deformity in treatment of fracture should be adjusted according to the increase of body weight-in other words, maturation.
Body Weight ; Bone and Bones ; Congenital Abnormalities ; Elastic Modulus ; Elasticity ; Plastics ; Rabbits ; Tibia

The concept of surface replacement arthroplasty of the hip is to replace the diseased joint surface with artificial plastic and metal cup in the acetabular and femoral head respectively, and to restore the normal anatomy and gain biomechanical function. Ten cases of Wagner type's surface replacement arthroplasty performed in Department of Orthopedic Surgery, Seoul National University Hospital since July 1979 are reviewed, and their minimum follow up is two months. In terms of the Pain control and improvement of range of motion in the hip, surface replacement arthroplasty showed about the same result compared with conventional total hip. In our cases there was no one complicatian, even though it is too short to evaluate the result of this operation. Wagner recommends surface replacement arthroplasty to perform through anterior approach, but 2 cases of our ten patients that have relatively good range of motion of the hip could be operated on this surgery by anterolateral approach (oblique skin incision) without trochanteric osteotomy, because of high incedence of myositis ossification with anterior approach. It is our conclusion that surface replacement arthroplasty of the hip may be used as an interim procedure to gain time in young patient who needs conventional total hip replacement which reveals increasing complication with the lapse of time.
Acetabulum ; Arthroplasty, Replacement ; Arthroplasty, Replacement, Hip ; Femur ; Follow-Up Studies ; Head ; Hip ; Humans ; Joints ; Myositis ; Orthopedics ; Osteotomy ; Plastics ; Range of Motion, Articular ; Seoul ; Skin

No Abstract Available.

Incorporation of bromodeoxyuridine(BrdU) and expression of osteocalcin and transglutaminase C(TGase C) during fracture healing and distraction osteogenesis were investigated in the rat with immunohistochemical studies. Transverse osteotomy was made at the proximal tibia. Bilateral dynamic mini-fixator was applied to immobilize the fracture and also to lengthen the leg. Distraction was started, at the rate of 0.25 mm twice daily, from the 4th operative day and continued for 7 days. Animals were killed for immunohistochemical studies on the 1st, 3rd, 5th, 7th, 14th, 28th, 42nd, 56th, and 84th day after osteotomy or distraction. Longitudinal histologic sections of the healing bone were stained with monoclonal antibodies against BrdU, osteocalcin, and TGase C. Radiologically, complete fracture healing was achieved in 6 weeks after osteotomy, while neo-osteogenesis was successfully achieved in the distracted gap in 7 weeks after the completion of distraction, During active healing stage of the fracture and distraction osteogenesis, BrdU was mainly expressed in the perisoteal and endosteal osteoprogenitor cells while osteocalcin was expressed in the proliferating osteoprogenitor cells, osteoblast, osteocyte, osteoid matrix, and chondrocyte. The expression of BrdU and osteocalcin in the mesenchymal cells from the surrounding soft tissues around the osteotomy site was negligible. At the site of enchondral bone formation, TGase C was expressed in the cytomplasm of more centrally located and matured chondrocytes, while oseocalcin was mainly expressed in the cytoplasm of peripherally located chondrocyte. These findings may suggest that osteocalcin participates in early phase of enchondral bone formation, while TGase C in the late phase, suggesting the role of TGase C in matrix stabilization. At the site of intramern-branous bone formation, the expression of TGase C was weakly positive in both osteoprogenitor cell and osteoblast. The reason of the difference in the expression of TGase C between the enchondral bone formation and intrarnembranous bone formation should be further investigated. Fracture healing and distraction osteogenesis was predominantly induced by intramembranous ossification rather than enchondral ossification. Periosteal osteoprogenitor cells appeared to initiate and to lead bone formation after osteotomy and distraction. Active proliferation and differentiation of osteoprogenitor cell ocurred during entire periods of distraction. Also, active osteoid matrix formation and mineralization was started from the 5th day of distraction and continued thereafter for further 4 weeks after completion of the lengthening. These findings indicate that preservation of the periosteum is essential to achieve successful fracture healing and distraction osteogenesis.
Animals ; Antibodies, Monoclonal ; Bromodeoxyuridine ; Chondrocytes ; Cytoplasm ; Fracture Healing ; Leg ; Miners ; Osteoblasts ; Osteocalcin ; Osteocytes ; Osteogenesis ; Osteogenesis, Distraction ; Osteotomy ; Periosteum ; Rats ; Tibia

No abstract available.
Growth Plate* ; Isoenzymes*

No abstract available.
Arthroplasty* ; Arthroplasty, Replacement, Knee*

No abstract available.
Ankle*

The purpose of this study is to compare the biologic properties of tendon to hone healing and hone to hone healing in knee ligament reconstruction. The lateral 4mm of patellar tendon which was detached from its tihial insertion site either subperiostcally(group I) or with a bone block(group II) was implanted and fixed using pullout method to the proximal tihia. Ten rabbits were killed at each of four time periods (two, four, eight and twelve weeks after the implantation), and the histological and biomechanical characteristics of thc graft healing sites were evaluated. Serial histological analysis of tendon to hone healing group revealed organization of the healing site similar to normal tendon to hone attachment by twelve weeks, while hone to bone healing group demonstrated direct hony union by eight weeks. The tension failure test for the patellapatellar tendon graft - tihia complex revealed that group II had significantly higher values than group I at four and eight weeks. The findings ot this study demonstrated that bone to hone healing has more rapid process than tendon to hone healing, although no significant difference was noted once the healing has matured. We can suggest lhat the duration and extent of postoperative protection of the knee for pntients who had a reconstruction of a ligament using hone - lendon autograft should be longer and higher than lor patients who had a reconstruction using hone - tendon hone autogralf.
Autografts* ; Dronabinol ; Humans ; Knee ; Ligaments ; Patellar Ligament* ; Rabbits* ; Tendons* ; Transplants

No abstract available.
Synovitis, Pigmented Villonodular*

Cubitus varus and cubitus valgus is one of late complications of elbow fracture. Tardy ulnar nerve palsy often accompanies with cubitus valgus. The authors reviewed 40 supracondylar osteotomies (on cubitus varus 31, cubitus valgus 9) performed at the Department of Orthopedic Surgery, Seoul National University Hospital, during the period of 15 years, from 1962 till 1976. During long term follow up, correction of elbow deformity and its maintenance is possible even in growing child. So early operation is recommended for the prevention of neurologic compIication and elbow stiffness.
Child ; Congenital Abnormalities ; Elbow ; Follow-Up Studies ; Humans ; Orthopedics ; Osteotomy ; Seoul ; Ulnar Neuropathies