Epiphyseal plate transplantation between sites of different growth potential

The purpose was to study epiphyseal plate growth after microvascular transplantation to sites of different growth potential. The hypothesis was that the growth potential of an epiphyseal plate transplant is a function of the donor irrespective of the recipient site to which it is transplanted. Immature rabbits were used in an experiment that transplanted microsurgically revascularized second metatarsal epiphyseal plates. There were three experimental groups in which transplants were made to (i) sites of the same growth potential (orthotopic), (ii) sites of higher growth potential (proximal tibia), and (iii) sites of lower growth potential (third metacarpal). Control groups were nonoperated animals, animals with an anteromedial proximal tibial osteotomy, and nonoperated contralateral limbs of all experimental animals. Postoperative graft viability was checked with fluorochrome labeling. Postoperative growth was measured from serial standardized radiographs. Follow-up was for either 5 or 8 weeks. Animals were then killed, and epiphyseal plate specimens removed for histomorphometric analysis. Results showed that the total growth of experimental second metatarsal transplants was not statistically different (p > 0.05) in any recipient site. It was noted, however, that transplanted epiphyseal plates in all experimental groups grew at lower rates than nonoperated controls.     

Can quantitative 99mTc-MDP bone scans be used to predict longitudinal growth of epiphyseal plate allografts after microvascular transplantation? An experimental study

Allograft and autograft microvascular proximal tibial epiphyseal plate transplants were performed in female New Zealand White (NZW) rabbits to quantify the growth rate and total growth potential of immunosuppressed and nonimmunosup-pressed rabbits. The purpose of this experiment is to examine whether the ^99mTc-MDP radionuclide uptake of the transplanted epiphyseal plate at 1 week postoperatively, done to assess anastomotic patency of the transplant, could also serve as a predictor of eventual longitudinal growth of the transplant or replant. All transplants and replants demonstrating positive ^99mTc-MDP uptake in the proximal tibial epiphyseal plate at 1 week showed continued longitudinal growth. The precise amount of ^99mTc-MDP uptake, however, did not correlate with the amount of growth at 3 and 5 weeks follow-up. © 1995 Wiley-Liss, Inc.     

Correction of hypoplastic thumb by free transfer of metatarsal bone: A case report

A new form of correction of hypoplasia of the thumb is presented in a case of grade 3 thumb hypoplasia. The distal half of the second metatarsal together with its epiphyseal plate was used to lengthen the first metacarpal bone and improve thumb function. This method represents a promising alternative to pollicization in this type of thumb hypoplasia. © 1993 Wiley-Liss Inc.     

Treatment of First Metatarsal Longitudinal Epiphyseal Bracket by Excision Before Closure

The longitudinal metatarsal epiphyseal bracket is a rare ossification abnormality of tubular bones in which an abnormal epiphysis brackets the diaphysis of a phalanx, metacarpal, or metatarsal. This leads to progressive shortening and angular deformity of the involved bone. When it affects the first metatarsal, the longitudinal metatarsal epiphyseal bracket leads to a short, trapezoidal metatarsal. We present the case of a 6-year-old patient with an ossified longitudinal epiphyseal bracket along the medial side of the first metatarsal. The abnormality was surgically treated by bracket excision before physeal closure. At 6 years' follow-up, the patient displayed a normally aligned hallux of appropriate size in proportion to the other toes. Surgical correction resulted in alteration of the first metatarsophalangeal angle, which went from a preoperative value of 13 degrees of hallux varus to a postoperative value of 9 degrees of hallux valgus; the first metatarsal intraosseous angulation went from a preoperative value of 30 degrees to a postoperative value of 5 degrees , and the metadiaphyseal length index went from a preoperative value of 0.39 to a postoperative value of 0.92. This case study demonstrates that early resection of an ossified abnormal bracket before physeal closure, a relatively simple procedure, can restore longitudinal growth and correct angular deformity.     

Growth retardation after experimental limb lengthening by epiphyseal distraction

Growth retardation occurring as a result of limb lengthening by epiphyseal distraction in two animal species was quantified by using femur or tibia as the experimental bone. The growth plate subjected to distraction appeared radiolucent after the lengthening procedure but was less distinct and had reduced height as compared with the control. In seven of 22 animals, the growth plate of the lengthened bone appeared to close earlier than in the control. After lengthening, bilateral longitudinal growth was evaluated semiquantitatively from radiographs until growth had ceased or residual growth was negligible. Growth retardation was consistently experienced in all animals, with an average reduction in growth potential of each study ranging from 40 to 70%. The results show that epiphyseal distraction is a valid method of limb lengthening, but it appears to have a consistently harmful effect on the growth plate and should be used clinically only in patients close to maturity.     

Metatarsal-slide lengthening without bone grafting

Brachymetatarsia is a condition of premature closure of the epiphyseal plate of a metatarsal. The authors present a case of brachymetatarsia of the second metatarsal. Utilizing a review of the literature, various surgical procedures are discussed. Treatment in this case consisted of a metatarsal-slide lengthening osteotomy, a modification of the Giannestras step-down procedure.     

Correcting and lengthening of metatarsal deformity with circular fixator by distraction osteotomy: a case of longitudinal epiphyseal bracket

The condition known as longitudinal epiphyseal bracket or delta phalanx is a rare congenital anomaly that affects the tubular bones of hand or foot. Metatarsal epiphyseal bracket restrains longitudinal growth, causing progressive deformity and resulting in a short, broad metatarsal and a medially deviated metatarsophalangeal joint and hallux magnus. Although there are some case series describing metatarsal lengthening with the unilateral fixator in the literature, we could not find any case that combines both metatarsal lengthening and deformity correction with the circular external fixator. Gradual lengthening and deformity correction without bone grafting and soft-tissue modification were carried out in a case with bilateral longitudinal epiphyseal bracket of the first metatarsals of the foot. A literature review and treatment method for epiphyseal bracket in a 9-year-old boy is presented. Excellent clinical, and functional results were obtained with circular and semicircular fixators.     

Die Reaktion der Epiphysenfuge auf fugenkreuzende Bohrdrahtosteosynthesen

In young rabbits of five to six weeks of age we revealed bony bridging as constant reaction of the epiphyseal cartilage on drilling with a 2 mm diameter trephine into the distal femur growth plate. Gross growth disturbancies will be the consequence of such partial closures. For this present study we inserted one 2 mm Kirschnerwire across the epiphyseal plate of the distal femur. The drilling was directed distally. During longitudinal growth the epiphysis moves away from the wire, that remains 8 weeks after the operation completely within the metaphyseal cancellous bone. Four, 8, 12 and 16 weeks postoperatively one group of the rabbits were sacrified. After radiological examination of the explanted femurs fixation and embedding in methylmetacrylate for morphological examination was performed. Our histological results reveal, that the crossing Kirschner-wire does not irritate the growth plate, even the physiological structure of the epiphyseal cartilage in the direct contact to the metal implant is not altered. The defect within the epiphyseal plate left after the relative retraction of the wire caused by growth activity fills with cancellous bone. Its trabecular structure is markedly thinner than the spongy bone within the metaphysis and shows longitudinal orientation. These trabeculae undergo segmental disruption by the growth pressure of the surrounding epiphyseal plate. In consequence there is no bone bridging and growth alterations by the Kirschner-wire crossing of the epiphyseal plate. This proves experimentally the clinical experienced therapeutic value of Kirschner-wires for internal fixation of dislocated joint injuries.     

Role of simple cold storage in preventing epiphyseal growth plate impairment after replantation surgery in immature rats

The purpose of this study was to investigate the effect of ischemia time on longitudinal bone growth after replantation, and to evaluate the usefulness of simple cold storage of an amputated limb in preventing epiphyseal growth-plate impairment. A hind-limb replantation model was produced with 5-week-old rats after various ischemia times. With more than 6 hr of warm ischemia, growth disturbance was observed, and extensive necrosis was histologically apparent in the central region of the growth plate of the proximal tibia, even at 1 week postoperatively. Destruction of the growth plate was complete at 4 weeks after surgery. By simple cold storage of the amputated limb, growth disturbance was not observed, even following ischemia for 9 hr, and no abnormal findings were observed histologically. Segmental necrosis and destruction of the growth plate observed histologically suggested the possibility of indirect impairment of the epipyseal chondrocytes due to disturbance of the epiphyseal arterial system, attributable to ischemia. The study confirmed experimentally that cold storage of the amputated part may prevent longitudinal bone-growth disturbance after extension of ischemia time.     

Development and validation of new model for microvascular transplantation of epiphyseal plate allografts with minimal adjoining epiphyseal and metaphyseal bone

A model for the free allograft microvascular transplantation of rabbit proximal tibial epiphyseal plate allografts was developed, validated, and tested in an in vivo animal model. Transplants contained the minimum amount of adjacent epiphyseal and metaphyseal bone compatible with preservation of the epiphyseal-plate vascular supply, as determined by corrosion casting. Perfusion to this graft was evaluated quantitatively using radioactive microspheres, and qualitatively using India-ink injection. Female New Zealand White rabbits at 12 weeks of age were utilized. Vascularized transplantation of epiphyseal plate allografts was performed either into a defect of matched size in the iliac crest or into a soft-tissue pocket without bone contact. Cyclosporine A immunosuppression (CSA) was administered daily for 6 weeks. Two control groups underwent identical surgical procedures, but had no postoperative immunosuppression. Epiphyseal plates both with and without bone contact, in rabbits immunosuppressed postoperatively with CSA, demonstrated longitudinal growth and preserved viability as determined by positive bromodeoxyuridine uptake. Control epiphyseal plates transferred without postoperative immunosuppression were uniformly nonviable. This new model has value as a basis for further studies into the clinical applicability of isolated epiphyseal-plate transplants.     

99mTc-DPD uptake in juvenile arthritis. Scintimetry and autoradiography of the knee in dogs

Unilateral arthritis of the knee was induced in mongrel puppies by intraarticular injections of 1% Carragheenan. Bone metabolism was studied by a scintimetric technique on static 99mTc-diphosphonate bone scans every 2nd week during the induction of arthritis for 3 months and monthly in a postarthritic phase of another 3 months. Changes in uptake of radionuclide were present after 2 weeks. The induction phase was characterized by a decreased uptake in the calcification layer of the juxta-articular growth plates and a moderately increased epiphyseal uptake. The postarthritic phase was characterized by normalization of growth plate uptake and a marked increase in epiphyseal uptake. Using contact autoradiography, the epiphyseal uptake was seen mainly in a narrow subchondral and subsynovial bone layer, around bone cysts and osteophytes, whereas central epiphyseal bone was osteopenic with decreased uptake of tracer. The study suggests that the early scintigraphic appearance of juvenile non-suppurative arthritis may be an overall decrease in uptake of 99mTc-diphosphonate due to a depression of growth plate metabolism.     

Transplantation of epiphyseal plate allografts between animals of different ages.

The purpose of the experiment was to study growth of epiphyseal plate allografts after transplantation into subjects of a different age, thus preparing for future transplantation of epiphyseal plate or extremity allografts in children. Microvascular transplantation of proximal tibial epiphyseal plate allografts was performed in skeletally immature New Zealand White female rabbits. The growth of 9-week-old epiphyseal plate allografts was examined in both 9-week-old and 17-week-old recipients, as was the growth of 17-week-old epiphyseal plate allografts in 17-week-old recipients. Immunosuppression was with cyclosporine (Cyclosporine A). Successful transplants were confirmed with 99mTc-MDP isotope scanning, and growth was evaluated with weekly standardized radiographs until death. Growth rate was found to depend on the age of the donor epiphyseal plate and was independent of the age of the recipient. This has clinical implications for the procurement of donor tissue in potential transplantation of epiphyseal plate allografts in children.     

骺板损伤的诊断与治疗进展

骺板损伤可导致骨骺与干骺端之间形成骨桥，骺板提前闭合，造成肢体短缩和(或)成角畸形，影响儿童生长发育。早期诊断较困难，X线、CT、MRI等影像学检查及“骨桥地图法”可协助诊断。传统治疗有骨桥切除后以脂肪、骨水泥等填塞，但效果不一。近年来，随着显微外科及组织工程等新技术的开展，用培养的骺软骨细胞、间充质干细胞等移植代替无活力的填充物植入，它能不断增殖并抑制骨桥形成，将为骺板损伤治疗提供更好的解决方案。本文结合国内外最新研究成果对骺板损伤的现状进行回顾，并对其前景作一展望。     

99mTc-DPD uptake in juvenile arthritis: Scintimetry and autoradiography of the knee in dogs

Unilateral arthritis of the knee was induced in mongrel puppies by intra-articular injections of 1% Carragheenan. Bone metabolism was studied by a scintimetric technique on static ^99mTc-diphosphonate bone scans every 2nd week during the induction of arthritis for 3 months and monthly in a postarthritic phase of another 3 months. Changes in uptake of radionuclide were present after 2 weeks. The induction phase was characterized by a decreased uptake in the calcification layer of the juxta-articular growth plates and a moderately increased epiphyseal uptake. The postarthritic phase was characterized by normalization of growth plate uptake and a marked increase in epiphyseal uptake.

Using contact autoradiography, the epiphyseal uptake was seen mainly in a narrow subchondral and subsynovial bone layer, around bone cysts and osteophytes, whereas central epiphyseal bone was osteopenic with decreased uptake of tracer.

The study suggests that the early scintigraphic appearance of juvenile non-suppurative arthritis may be an overall decrease in uptake of ^99mTc-diphosphonate due to a depression of growth plate metabolism.     

Effects of alendronate and pamidronate on cultured rat metatarsal bones: failure to prevent dexamethasone-induced growth retardation

Bisphosphonates are widely used anti-resorptive drugs in the adult population. In children, their use has mainly been limited to patients with osteogenesis imperfecta. However, the powerful effects of bisphosphonates on bone turnover have raised concern about their long-term effects on the growing skeleton. We aimed to study the effects of two commonly used bisphosphonates, alendronate (Aln) and pamidronate (Pam) on normal bone growth as well as their potential to prevent glucocorticoid-induced growth retardation. Effects on bone growth were studied in fetal rat metatarsal bones (day E20) that were cultured for 5-47 days and measured every 2-7 days. Cellular mechanisms were investigated in metatarsal bones and also in the human chondrocytic cell line HCS-2/8. Chondrocyte viability (WST-1), proliferation (BrdU incorporation), differentiation (collagen type X immunohistochemistry) and apoptosis (TUNEL and Cell Death ELISA) were determined. At a clinically relevant concentration of bisphosphonates (1 microM), metatarsal bone growth was stimulated by both Aln (p<0.001 for length and p<0.05 for width) and Pam (p<0.05 for both length and width) from day 19 of culture. The growth-stimulatory effect was associated with increased chondrocyte proliferation (+21% with Aln and +24% with Pam), while cell differentiation and apoptosis were not affected. Despite the finding that both Aln and Pam (1 muM) rescued HCS-2/8 cells from undergoing dexamethasone-induced apoptosis, neither of them was able to prevent dexamethasone-induced growth retardation of fetal rat metatarsal bones. Aln and Pam have the capacity to stimulate the growth of cultured fetal rat metatarsal bones; an effect associated with increased proliferation of growth plate chondrocytes. Our experimental data suggest that bisphosphonates are ineffective in preventing glucocorticoid-induced growth retardation. Nevertheless, based on our in vitro data, both Aln and Pam appear safe to use in growing children, at least with regard to their effects on linear bone growth.     

Influence of Frontal and Dorsal Loads on Muscle Activity and on the Weight Distribution in the Feet

Unilateral arthritis of the knee was induced in mongrel puppies by intra-articular injections of 1% Carragheenan. Bone metabolism was studied by a scintimetric technique on static ^99mTc-diphosphonate bone scans every 2nd week during the induction of arthritis for 3 months and monthly in a postarthritic phase of another 3 months. Changes in uptake of radionuclide were present after 2 weeks. The induction phase was characterized by a decreased uptake in the calcification layer of the juxta-articular growth plates and a moderately increased epiphyseal uptake. The postarthritic phase was characterized by normalization of growth plate uptake and a marked increase in epiphyseal uptake.

Using contact autoradiography, the epiphyseal uptake was seen mainly in a narrow subchondral and subsynovial bone layer, around bone cysts and osteophytes, whereas central epiphyseal bone was osteopenic with decreased uptake of tracer.

The study suggests that the early scintigraphic appearance of juvenile non-suppurative arthritis may be an overall decrease in uptake of ^99mTc-diphosphonate due to a depression of growth plate metabolism.     

The effects of cold upon bone growth: a preliminary study

The effects of various degrees of cold injury upon bone growth were experimentally studied. Young rabbits' feet, rendered ischemic by the application of a tourniquet, were cooled down by immersion in either an ice bath at 0 degrees C or an alcohol bath at -20 degrees C. The bone injuries were assessed clinically, radiologically, and histologically. Prolonged exposures to low temperatures above freezing do not cause any bone damage. Brief exposures to temperatures between -20 degrees C and -15 degrees C affect bone growth by inducing premature arrest of the epiphyseal plate, destruction of the epiphysis, and reactive-endosteal and periosteal bone formation. These effects lead to a statistically significant shortening and widening of the affected bones, which can be demonstrated radiologically. Low temperatures have a primary direct lethal effect upon the highly sensitive chondrocytes of the epiphyseal growth plate. Bone damage is independent of associated soft-tissue injuries and not linked to frostbite of the extremity or to solidification of tissues.     

Spontaneous epiphyseal injury as a complication of a simple bone cyst of the femoral neck? Case report and review of the literature

A case of a spontaneous epiphyseal injury of the femoral neck in an 8-year-old boy is reported. The same boy had been seen 8 months before for a pathological fracture caused by a simple bone cyst of the femoral neck on the same side. At the second visit the boy showed spontaneous severe pain of the hip, and radiography was performed under the presumed diagnosis of a slipped capital femoral epiphysis. However, it demonstrated a separation through the growth plate cranially and a fracture through the metaphysis inferiorly, leading to the differential diagnosis of a Salter-Harris type II fracture despite a nontraumatic patient history.A review of the literature failed to reveal a similar report of simultaneous occurrence of a simple bone cyst and epiphyseal injury of the femur. However, slipping of the proximal humeral epiphysis in connection with a simple bone cyst has been described by some authors. We propose a pathophysiological model for the simultaneous occurrence of epiphyseal injury and a simple bone cyst. Physeal involvement by a simple bone cyst and varus deformity of the femoral neck could cause weakening of the growth plate and predispose for epiphyseal injury.Based on these findings, we suggest that a simple bone cyst of the proximal femoral metaphysis can develop into a severe condition. Children presenting with this clinical picture should be treated vigorously and monitored for the development of complications leading to epiphyseal injury.     

Epiphyseal injuries of the foot and ankle

A thorough knowledge of functional growth plate anatomy and physiology is essential to proper management of epiphyseal foot and ankle injuries. The ability to classify foot and ankle fractures according to the Salter-Harris anatomic and radiographic classification provides useful prognostic information that may affect treatment. The Dias-Tachdjian mechanistic classification system for pediatric ankle fractures provides useful information about the extent of osseous and soft tissue injury and the best method of closed reduction and correlates well with the Lauge-Hansen system, which is widely used for adult ankle fractures. Most epiphyseal foot fractures involve the metatarsals or phalanges and can usually be managed with closed reduction. Considerable spontaneous correction of deformity can be expected in the younger child (under age 10 years), but one should be aware that sagittal plane and rotational malalignment of the metatarsal heads may cause significant problems. Salter-Harris type I and II fractures of the ankle can usually be managed with closed reduction. Salter-Harris type III and IV ankle fractures with greater than 2 mm of displacement require open reduction and internal fixation. One must also have a high index of suspicion for juvenile Tillaux and triplane transitional fractures that may not be obvious on plain radiographs. Although these fractures usually do not produce significant limb-length discrepancies, they are intra-articular fractures and ankle joint arthritis can result. Finally, younger children (under age 10 years) have a better prognosis for spontaneous correction of nongrowth arrest-induced deformities but a much poorer prognosis with growth arrest injuries than do older children, in whom growth arrest does not usually cause a significant problem. All children with growth plate injuries should be followed at regular intervals for at least 2 years or to skeletal maturity in the case of physeal disturbance. Treatment of epiphyseal fractures of the foot and ankle must be individualized but should always be based upon a thorough knowledge of anatomy, bone growth physiology, classification, potential pitfalls, and prognosis.