Effects of irradiation on the appositional and longitudinal growth of the tibia and fibula of the rat with and without radioprotectant

The effect of therapeutic levels of irradiation on appositional bone growth was compared with its effect on longitudinal growth in the skeletally immature rat model. The widths and lengths of the tibiae and fibulae of young rats were studied at 2, 4, 6, and 12 weeks after exposure to 17.5 Gy x-irradiation to the knee region of the right leg, with and without the aminothiol radioprotectant amifostine 20 minutes before radiation. Irradiation retarded growth in the width of the tibia to a greater extent (19%-27%) than longitudinal growth (9%-21%). The appositional growth discrepancy decreased over time, whereas the length discrepancy increased. The proximal fibula, in contrast, undergoes a normal decrease in width over time, and irradiation retarded this contraction by 14%. Appositional growth does not appear to be spared from the damaging effects of irradiation, but a catch-up phenomenon is observed that is not seen in longitudinal growth. Amifostine reduced the radiation-induced loss in tibial width by 40% to 50% and in length by 12% to 30%.     

胫骨骨干端延长对胫骨生长板纵向生长的影响

[目的]研究胫骨骨干端截骨延长对胫骨生长板和纵向生长的影响。[方法]建立兔胫骨骨干端截骨和延长的动物模型;拍摄标准胫骨放射照片以测量其长度,胫骨远近端骨骺生长板做成组织切片以测量其厚度。[结果]胫骨中部骨干行单纯截骨后,增加胫骨纵向生长和胫骨远近端骨骺生长板的厚度,胫骨中部骨干行截骨延长后,胫骨纵向生长和胫骨远近端骨骺生长板的厚度没有改变。[结论]胫骨骨干截骨延长术不会妨碍胫骨的纵向生长。     

The effect of tibial diaphyseal lengthening on the longitudinal growth of the tibia

Limb lengthening by tibial callotasis is usually performed in the metaphysis but may cause growth inhibition. Is diaphyseal lengthening more advantageous? Sixteen immature rabbits underwent 30% diaphyseal lengthening by tibial callotasis. The tibial length was measured on radiographs at the end of the distraction period and after an additional 5 weeks. The proximal and distal growth plates were assessed histomorphometrically. Osteotomy stimulated tibial elongation; however, combined with diaphyseal lengthening the stimulation was suppressed resulting in longitudinal growth that matched the control side. In longer lengthenings of limbs diaphyseal callotasis may be more advantageous than metaphyseal by not inhibiting longitudinal growth.     

Congenital longitudinal deficiency of the tibia

Fifty-seven patients (seventy-one limbs) who had congenital longitudinal deficiency of the tibia (tibial hemimelia) were retrospectively categorized according to radiographic type (Types 1 through 4, as described by Jones et al.). At an average follow-up of nine years, fifty-six of fifty-seven patients walked independently. An ablative surgical procedure was performed on sixty-one of the seventy-one lower extremities. According to the classification of Jones et al., fifty-four limbs had a Type-1 (a or b) or Type-2 deficiency. In twenty-two of these extremities, disarticulation of the knee was performed; in twenty-five, a Syme amputation; and in one, a Chopart amputation. The ipsilateral foot was retained in six extremities that had a severe Type-1 or Type-2 deficiency. Medial transfer of the fibula (the Brown procedure) generally yielded less than satisfactory results; in ten of fourteen extremities, one or more additional operations were needed. Seventeen extremities were classified as having a Type-3 or Type-4 deficiency; Syme amputation was done in nine and Chopart amputation, in four. Despite satisfactory reconstruction of the ankle, a Syme amputation was necessary in most extremities that had a Type-4 deficiency because a major leg-length discrepancy was projected. In four limbs that had a Type-3 or Type-4 deficiency, the foot was retained.     

Congenital longitudinal deficiency of the tibia

We performed a clinical and radiographic review of 15 patients (19 limbs) with longitudinal deficiency of the tibia treated between 1981 and 2001. Ten limbs with Kalamchi type I deficiencies were managed by through-knee amputation. Five type II deficiencies were treated by foot ablation and tibiofibular synostosis, either at the same time or staged, but prosthetic problems may arise from varus alignment and prominence of the proximal fibula. Patients with type III deficiencies (four cases) were treated by foot ablation. Prosthetic problems relating to proximal or distal tibiofibular instability may necessitate additional surgical intervention.

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Résumé Nous avons fait une révision clinique et radiographique de 15 malades (19 membres) présentant une déficience longitudinale du tibia traitée entre 1981 et 2001. Dix membres avec un déficit type Kalamchi type I ont été traités par une désarticulation du genou. Cinq type II ont été traités par ablation du pied et synostose tibiofibulaire, en un ou plusieurs temps, mais, dans ces cas des problèmes prothétiques peuvent survenir à cause d'un varus ou de la proéminence du péroné proximal. Les malades avec un type III (quatre cas) a été traité par l'ablation du pied. Les problèmes prothétiques en relation avec une instabilité tibiofibulaire proximale ou distale peuvent nécessiter une intervention chirurgicale supplémentaire.

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Rate of normal longitudinal bone growth in the rat

The rate of normal growth in length from the proximal growth plate of the tibia in the Sprague-Dawley rat was measured between 20 and 100 days of age using the tetracycline method. The growth rate varied only slightly within different age groups. The rate was highest in young animals and decreased considerably with increasing age. Male rats grew faster than female. This study is intended to provide a base for an evaluation of experimental influence on the growth in length of the rat.

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Zusammenfassung Die normale Längenwachstums-Geschwindigkeit der proximalen Wachstumsplatte der Tibia wurde bei Sprague-Dawley-Ratten in einem Alter zwischen 20 und 100 Tagen mittels der Tetracyclinmethode gemessen. Die Wachstumsgeschwindigkeit variierte nur wenig innerhalb der einzelnen Altersgruppen. Die Geschwindigkeit war bei jungen Tieren am höchsten und nahm mit zunehmendem Alter beträchtlich ab. Männliche Ratten wuchsen schneller als weibliche. Diese Arbeit dient als Grundlage, um die experimentelle Beeinflussung des Längenwachstums der Ratte abschätzen zu können.

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Résumé La vitesse de croissance normale en longueur de la métaphyse proximale du tibia est déterminée chez le rat Sprague-Dawley entre les âges de 20 et 100 jours, en utilisant la méthode à la tétracycline. Le taux de croissance ne varie que légèrement dans les groupes d'âges différents. Il est plus élevé chez les animaux jeunes et décroit considérablement en fonction de l'augmentation de l'âge. Les rats mâles présentent une croissance plus élevée que les femelles. Cette étude a pour but de mettre au point une méthode permettant de déterminer les facteurs expérimentaux, liés à la croissance en longueur du rat.

     

Effect of hypophysectomy on longitudinal bone growth in the rat

The effect of hypophysectomy on the growth in length from the proximal growth plate of the tibia in female Sprague-Dawley rats was studied with the tetracycline method. The body weight was registered. The completeness of the hypophysectomy was determined microscopically on serial sections of the sella turcica. Hypophysectomy was found to have a retarding effect on longitudinal bone growth. In animals operated at 40 days of age the growth does not cease. The longitudinal growth decreases and reaches a low basal level about 10 days postoperatively. A single dose of 45 mg/kg cortisone acetate given at hypophysectomy has a growth retarding effect postoperatively. When hypophysectomy was performed at 30, 40, 50, or 60 days of age, young animals have a higher basal growth rate than older animals. The width of the fluorescent band, corresponding to a postoperative injection of oxytetracycline, is correlated to the growth rate and can be used as an index of the growth rate. The postoperative accumulated growth and the width of the fluorescent band indicate the functional efficacy of the hypophysectomy, and make it possible to separate animals with complete and incomplete hypophysectomy. Knowledge about the basal growth is important for the evaluation of the growth stimulating effect of different hormones.     

骨膜内双段腓骨复合小腿外侧皮瓣移植修复胫骨及皮肤缺损

目的：探讨下肢胫骨及皮肤缺损同时修复的临床方法。方法将腓血管制成1个或2个血管襻,该血管襻携带皮瓣,再将多段腓骨于骨膜内复合在一起,使成为一个骨膜包裹的粗骨修复胫骨与皮肤缺损。有丰富血运的骨膜,其骨膜下新生骨活跃,该新生骨充填骨膜内与腓骨段间隙、包绕腓骨,使移植腓骨增粗。结果3例胫骨缺损均获得良好骨愈合,移植骨无折断,皮瓣成活良好。供腓骨侧踝关节稳定,伸屈范围正常,功能恢复正常。结论骨膜内双段腓骨复合小腿外侧皮瓣移植是修复胫骨与皮肤缺损的良好方法。     

Bone cell kinetics during longitudinal bone growth in the rat

Summary The purpose of this work was to provide further knowledge about bone cell kinetics in the metaphysis of the growing long bone. Seventy rats were sacrificed from 1 to 120 h after injection of tritiated thymidine. Autoradiographs of 3 μm thick sections of the proximal tibial metaphysis were studied in a manner which allowed evaluation of labeled cell nuclei as a function of increasing age of metaphyseal tissue. A cell cycle duration study for osteoprogenitor cells was done. Labeled osteoprogenitor cells and osteoblasts first appeared at 1 h post-injection. The great majority of all labeled osteoprogenitor cells and osteoblasts was found within 1 mm of the growth cartilage-metaphyseal junction (GCMJ) at all times, apparently migrating with the moving GCMJ. In contrast, labeled osteoclast nuclei first appeared at 24 h post-injection within 0.3 mm of the GCMJ and remained always with the area of bone surface with which they were first associated, even as the GCMJ migrated away. By 5 days post-injection, the source of new labeled osteoclast nuclei in the metaphysis near the GCMJ was depleted, whereas that for the osteoblasts remained. The existence of two kinetically different, as well as ultrastructurally different, members of the metaphyseal osteoprogenitor cells population is postulated. A cell cycle time of 39±18 h was found for the osteoprogenitor cell population, but has limited meaning. A schema for metaphyseal bone cell movements during longitudinal bone growth is presented.     

3 cases of longitudinal stress fracture of the tibia

A 62-year-old man rose from a crouched position with a twisting motion and developed pain in the lower third of his left tibia. 2 weeks later, radiographs were normal. Pain persisted and 3 months later radiographs revealed a longitudinal lucency in the distal tibia on the lateral view and a corresponding thin sclerotic band on the AP view suggesting a stress fracture (Figure). The leg was immobilized in a cast. A CT scan confirmed a healing stress fracture with endosteal and subperiosteal new bone formation. The cast was removed at 6 weeks, radiographs showed healing and the patient has remained asymptomatic.     

Effect of growth zone injury on growth in the tibia of rabbits

Damaging the ossification centre of the proximal epiphysis of the tibia, the articular disc and the metaphysis of rabbits, the effect of injury on growth and the capacity for tissue regeneration during growth were studied radiologically and histologically. The injury penetrating into the metaphysis, directly damaging the articular disc gave rise to a more serious growth disturbance at the proximal end of the tibia than did the injury localized to the epiphyseal ossification centre. Tissue regeneration resulted in a richly vascularized granulation tissue in the injured region, with subsequent spongy bone formation. The hyaline cartilage did not regenerate.     

Failure of centralization of the fibula for congenital longitudinal deficiency of the tibia

Between 1962 and 1983, fourteen patients (twenty knees) had centralization of the fibula for congenital longitudinal deficiency: tibial, complete. Eleven of the twenty index procedures were performed on patients who were one year old or less. A progressive flexion deformity of the knee developed after all twenty index procedures. Twenty-six secondary procedures were needed, including disarticulation at the knee, posterior release, extension osteotomy, femorofibular arthrodesis, and biceps-to-quadriceps transfer, and one patient had a second attempt at centralization of the fibula. The duration of follow-up after the initial centralization of the fibula ranged from four years to twenty-two years and seven months (average, twelve years and four months). Seven patients (eight limbs) in whom the index procedure resulted in failure had a satisfactory result after disarticulation at the knee. The patients who did not have secondary disarticulation at the knee are also considered to have had a failed index procedure because they had a flexion deformity at the latest follow-up. Attempts to reconstruct the knee joint by centralization of the fibula are not warranted for patients who have congenital longitudinal deficiency: tibial, complete. Early disarticulation at the knee and fitting with a prosthesis, with close follow-up, is the treatment of choice.     

Modulation of appositional and longitudinal bone growth in the rat ulna by applied static and dynamic force

Appositional and longitudinal growth of long bones are influenced by mechanical stimuli. Using the noninvasive rat ulna loading model, we tested the hypothesis that brief-duration (10 min/day) static loads have an inhibitory effect on appositional bone formation in the middiaphysis of growing rat ulnae. Several reports have shown that ulnar loading, when applied to growing rats, results in suppressed longitudinal growth. We tested a second hypothesis that load-induced longitudinal growth suppression in the growing rat ulna is proportional to time-averaged load, and that growth plate dimensions and chondrocyte populations are reduced in the loaded limbs. Growing male rats were divided into one of three groups receiving daily 10 min bouts of static loading at 17 N, static loading at 8.5 N, or dynamic loading at 17 N. Periosteal bone formation rates, measured 3 mm distal to the ulnar midshaft, were suppressed significantly (by 28-41%) by the brief static loading sessions despite normal (dynamic) limb use between the daily loading bouts. Static loading neither suppressed nor enhanced endocortical bone formation. Dynamic loading increased osteogenesis significantly on both surfaces. At the end of the 2 week loading experiment, loaded ulnae were approximately 4% shorter than the contralateral controls in the 17 N static and dynamic groups, and approximately 2% shorter than the control side in the 8.5 N static group, suggesting that growth suppression was proportional to peak load magnitude, regardless of whether the load was static or dynamic. The suppressed growth in loaded limbs was associated with thicker distal growth plates, particularly in the hypertrophic zone, and a concurrent retention of hypertrophic cell lacunae. Negligible effects were observed in the proximal growth plate. The results demonstrate that, in growing animals, even short periods of static loading can significantly suppress appositional growth; that dynamic loads trigger the adaptive response in bone; and that longitudinal growth suppression resulting from compressive end-loads is proportional to load magnitude and not average load.     

Osteoconductivity of thermal-sprayed silver-containing hydroxyapatite coating in the rat tibia

A silver-containing hydroxyapatite (Ag-HA) coating has been developed using thermal spraying technology. We evaluated the osteoconductivity of this coating on titanium (Ti) implants in rat tibiae in relation to bacterial infection in joint replacement. At 12 weeks, the mean affinity indices of bone formation of a Ti, an HA, a 3%Ag-HA and a 50%Ag-HA coating were 97.3%, 84.9%, 81.0% and 40.5%, respectively. The mean affinity indices of bone contact of these four coatings were 18.8%, 83.7%, 77.2% and 40.5%, respectively. The indices of bone formation and bone contact around the implant of the 3%Ag-HA coating were similar to those of the HA coating, and no significant differences were found between them (bone formation, p = 0.99; bone contact, p = 0.957). However, inhibition of bone formation was observed with the 50%Ag-HA coating. These results indicate that the 3%Ag-HA coating has low toxicity and good osteoconductivity, and that the effect of silver toxicity on osteoconductivity depends on the dose.     

Longitudinal growth of the femur and tibia after diaphyseal lengthening

Growth of the femur and tibia after lengthening of their diaphyses, which had been performed several years before skeletal maturity, was assessed in eighteen patients by serial orthoroentgenograms. The rate of growth of the lengthened femora, which had been congenitally short, increased after each of seven lengthening procedures, from an average preoperative rate of 82 per cent of the normal side to 90 per cent of the normal side. The amount of surgical lengthening was similar for the femora and the tibiae, averaging 18 per cent of the preoperative length of the bone in the femora and 20 per cent of the preoperative length of the bone in the tibiae. However, the rate of growth of the lengthened tibiae decreased after each of eleven lengthening procedures (six performed for a congenital short tibia; three, for patients who had Ollier's disease; one, for a patient who had poliomyelitis; and one, for a patient who had hemangiomas), from an average preoperative rate of 88 per cent of normal to an average of 64 per cent of normal.