Deformity progression in congenital posteromedial bowing of the tibia: a report of 44 cases

BACKGROUND

congenital posteromedial bowing of tibia (CPMBT) is a very rare birth defect, characterized by shortened bowed leg and ankle deformity. We described a single institution experience in the management of CPMBT.

METHODS

we identified 44 CPMBT in 44 children. The age at presentation was 5.5 ± 5.6 years and the mean age at the final review was 10.1 ± 4.8 years. Radiographic evaluation included the antero-posterior and lateral inter-physeal angle (AP-IPA and L-IPA), the limb length discrepancy (LLD), the morphology of the distal tibia and the lateral distal tibial angle (LDTA). During the study period, 26 children underwent surgical treatment.

RESULTS

the estimated curves showed a progressive spontaneous correction of both AP-IPA and L-IPA during growth, but a progressive increase of the LLD. The L-IPA showed a more predictable behaviour while the AP-IPA showed a scattered correction, with a wider variation of the estimated final angle. The final LDTA was 85.3° ± 4.2° and was correlated with the L-IPA (r = 0.5; p = 0.02). Among the 26 children who underwent surgical treatment, 23 cases had limb lengthening, 1 case had contralateral epiphysiodesis, 1 child underwent tibial osteotomy, 1 patient was treated by hemiepiphysiodesis of the distal tibia to correct ankle valgus deformity.

CONCLUSIONS

our study described the largest case series of CPMBT. A combination of surgical treatments, in a staged surgical process, should be tailored to the developmental characteristics of this abnormality. An experience-based algorithm of treatment is also proposed. Further studies are needed to understand which is the best strategy to correct this deformity during childhood.

LEVEL OF EVIDENCE

level IV prognostic study.

Morphometric study of the primary ossification center of the fibular shaft in the human fetus

PURPOSES

Precise morphometric data on the development of ossification centers in human fetuses may be useful in the early detection of skeletal dysplasias associated with delayed ossification center development and mineralization. The present study was performed to quantitatively examine the primary ossification center of the fibular shaft with respect to its linear, planar and volumetric parameters.

MATERIALS AND METHODS

Using methods of CT, digital-image analysis (Osirix 3.9 MD) and statistics (Student's t-test, Shapiro-Wilk, Fisher's test, Tukey's test, Kruskal-Wallis test, regression analysis), the size of the primary ossification center of the fibular shaft in 47 spontaneously aborted human fetuses (25 ♂ and 22 ♀) aged 17-30 weeks was studied. In each fetus, the assessment of linear dimensions (length, transverse diameters for: proximal end, middle part and distal end), projection surface area and volume of the fibular shaft ossification center was carried out.

RESULTS

With no sex and laterality differences, the best fit growth dynamics for the primary ossification center of the fibular shaft was modelled by the following functions: y = - 13.241 + 1.567 × age ± 1.556 (R2 = 0.94) for its length, y = - 0.091 + 0.063 × age ± 0.073 (R2 = 0.92) for its proximal transverse diameter, y = - 1.201 + 0.717 × ln(age) ± 0.054 (R2 = 0.83) for its middle transverse diameter, y = - 2.956 + 1.532 × ln(age) ± 0.090 (R2 = 0.89) for its distal transverse diameter, y = - 69.038 + 4.699 × age ± 4.055 (R2 = 0.95) for its projection surface area, and y = - 126.374 + 9.462 × age ± 8.845 (R2 = 0.94) for its volume.

CONCLUSIONS

The ossification center in the fibular shaft follows linear functions with respect to its length, proximal transverse diameter, projection surface area and volume, and natural logarithmic functions with respect to its middle and distal transverse diameters. The obtained morphometric data of the fibular shaft ossification center is considered normative for their respective prenatal weeks and may be of relevance in both the estimation of fetal age and the ultrasound diagnostics of congenital defects.

Hypertrophy Associated With Vascular Malformations: Analysis of Growth and Results of Epiphysiodesis

Limb-length inequality is a clinical problem in children with hypertrophy associated with vascular malformations. The purpose of this study was to determine a pattern of growth, predict discrepancy at maturity, and evaluate the timing and results of epiphysiodesis. Hypertrophy with vascular malformation, follow-up from childhood until maturity, annual physical examination, and annual orthoroentgenograms and anteroposterior left hand-wrist radiographs were the inclusion criteria. The developmental pattern of the growth discrepancy was established. Limb-length discrepancy and remaining growth were calculated. All 3 patients underwent distal femur or proximal tibia and fibula percutaneous epiphysiodesis. All cases showed the constant upward slope of the developmental pattern of discrepancy until the time of epiphysiodesis. The length of the uninvolved limb at maturity corresponded to the length predicted by the methods that used skeletal age, allowing calculation of the proper timing for epiphysiodesis. The multiplier and the rule of thumb methods failed, with skeletal age not corresponding to chronological age. In these 3 cases, limb-length discrepancy was successfully treated with percutaneous epiphysiodesis, and there were no complications. [Orthopedics. 2018; 41(4):e574-e579.].

Amniotic band syndrome with pseudoarthrosis of tibia and fibula: A case report

Constriction of the lower limb by congenital amniotic band has been proposed to explain the development of pseudoarthrosis of tibia and fibula. We report a case of amniotic band syndrome in a preterm infant with pseudoarthrosis of tibia and fibula. Simple release of constriction band with Z-plasty resulted in the growth of mature bone, replacing the pseudoarthrosis and hence did not require surgical amputation. Our case confirms the potential for bone growth in ABS, once the constricting band is released. Early limb preserving surgery with release of the constricting band with an intention to salvage the limb appears appropriate.

Long bone robustness during growth: A cross-sectional pQCT examination of children and young adults aged 5-29years

Skeletal robustness (cross-section size relative to length) is associated with stress fractures in adults, and appears to explain the high incidence of distal radius fractures in adolescents. However, little is known about the ontogeny of long bone robustness during the first three decades of life. Therefore, we explored the ontogeny of tibial, fibular, ulnar and radial robustness in a cross-sectional sample of 5 to 29year-old volunteers of both sexes. Peripheral quantitative computed tomography (pQCT) was used to evaluate cross-sections of the leg (4%, 14%, 38% and 66%), and forearm (4%, and 66%) in N=432 individuals. Robustness was evaluated as the total bone area divided by bone length. Differences between age-groups, sexes, and age-group×sex interactions were evaluated with ANOVA with Tukey's post hocs where appropriate. Most bone sites exhibited more robust bones in men than women (P<0.001 to 0.02), and in older age-groups than younger (P<0.001). Sex×age-group interaction was observed at the 66% and 38% tibia sites with robustness increasing more with age in men than in women (P=0.006 to 0.042). Post-hoc analyses indicated no sex differences prior to 13years-of-age, and notable exceptions to increasing robustness with age at the 4% radial and 66% tibial sites, which exhibited reduced robustness in age groups close to peak height velocity. In conclusion, the present results suggest that very little sexual dimorphism in long bone robustness exists prior to puberty, and that divergence occurs primarily after cessation of longitudinal growth. A period of relative diaphyseal slenderness was identified at age-groups coinciding with the adolescent growth spurt, which may be related to the relatively high incidence of frank and stress fracture in adolescents.

Development of genu varum in achondroplasia: relation to fibular overgrowth

Genu varum in the achondroplastic patient has a complex and multifactorial aetiology. There is little mention in the literature of the role of fibular overgrowth. Using the ratio of fibular to tibial length as a measurement of possible fibular overgrowth, we have related it to the development of genu varum. Full-length standing anteroposterior radiographs of 53 patients with achondroplasia were analysed. There were 30 skeletally-immature and 23 skeletally-mature patients. Regression analysis was performed in order to determine if there was a causal relationship between fibular overgrowth and the various indices of alignment of the lower limb. Analysis showed that the fibular to tibial length ratio had a significant correlation with the medial proximal tibial angle and the mechanical axial deviation in the skeletally-immature group. We conclude that there is a significant relationship between fibular overgrowth and the development of genu varum in the skeletally-immature achondroplastic patient.

Evaluation of activity of epiphyseal plates in growing males and females

To investigate the age-related activity of the epiphyseal plates, a retrospective study of (99m)Tc-methylene diphosphonate bone scans was undertaken. The study comprised 81 males and 46 females aged 2 weeks to 24 years. The total percentage (%) whole-body (ratio of total physis activity to whole-body activity) and the regional % whole-body (ratio of physis activity of one region to whole-body activity) were derived. The ratio of physis activity of one region to the total physis activity was defined as % physis. Before age 12, total physis activity was found to contribute about 10% to whole-body activity. All total and regional % whole-body activities followed sigmoid curves with age. The differences of the parameters (transition centers and widths) suggested that there might be a later and longer period for the disappearance of physis activity in males than in females. For all the regions, % physis changed little with age until after puberty. At age <1, the proportion of bone activity in the body was about 30-35% for skull, 20-25% for lower limbs, and 5-15% for the rest of the regions. The maximal changes during growth occurred in the skull and the lower limbs. The age-related changes of physis activity during growth reflect a combination of the potential of bone to grow and the processes of bone growth and bone turnover. Bone scintigraphy is useful in understanding the changes of physis activity during growth.

Irreversible morphological changes in leg bone following chronic gravitational unloading of growing rats

Effects of gravitational unloading or loading on the growth and development of hindlimb bones were studied in rats. Male Wistar rats were hindlimb-unloaded or loaded at 2-G from the postnatal day 4 to month 3. The morphology and mineral content of tibia and fibula, as well as the mobility of ankle joints, were measured at the end of 3-month suspension or loading, and 1, 2, and 3 months after ambulation recovery. Growth-related increases of bone weight and mineral density were inhibited by unloading. But they were gradually recovered toward the control levels, even though they were still less than those in the age-matched controls after 3 months. None of the parameters were influenced by 2-G loading. However, here we report that chronic unloading causes abnormal morphological development in hindlimb bone of growing rats. Irreversible external bend of the shaft and rotation of the distal end of tibia, which limit the dorsiflexion of ankle joints, were induced following chronic gravitational unloading during developing period. It is also suggested that such phenomena are caused by the abnormal mechanical forces imposed by muscle utilization with altered patterns. The activity of ankle dorsiflexor was increased and that of plantarflexor was inhibited during unloading.

Partial physeal growth arrest treated by bridge resection and artificial dura substitute interposition

We treated four cases of partial physeal growth arrest by resecting the bone bridge and interposing an expanded polytetrafluoroethylene membrane, which has minimal tissue response. We evaluated three cases with sufficiently long follow-up. No apparent recurrence of the bone bridge and no limb length discrepancy occurred in any of the cases. No remodeling after the operation occurred. In one case, which underwent this operation and corrective osteotomy of the proximal tibia, slight recurrence of the varus deformity occurred which was detected only by radiographs, and did not compromise the alignment of the leg. There were no complications.

[Growth defects of fibular flaps in children]

BACKGROUND

Mandibular reconstruction with fibula free flap is a challenge in pediatric patients because of the size of the bone and absence of growth without epiphyseal transplantation.

CASE REPORT

We report 2 cases of free fibula flap in children for mandibular reconstruction. The 2 patients presented with growth insufficiency of the bone graft after few years of evolution.

DISCUSSION

Growth insufficiency was treated with different surgical procedures which were discussed We review the consequences on growth after fibula free flap and the specific indications to achieve epiphyseal fibular growth in children.

The corpus fibulae in sheep (Ovis ammon f. aries)--ontogeny, persistence, size and shape from the fetal period to adulthood

Osteological characteristics are often used to identify animal species. In this regard it is believed that the corpus fibulae of the sheep is represented by a tight cord of connective tissue--the so-called "ligamentum fibulare". The results of the present morphometric study indicate, however, that in 67% of the fetuses, 61% of the lambs or 48% of the adult sheep out of the 160 examined animals, the corpus fibulae is represented by a pin-shaped flattened piece of bone. The length of the corpus fibulae increases with age and varies greatly between individuals but in lambs and adult animals its centre is located close to the border between the proximal and intermediate third of the tibia (distal type) or closely attached to the caput fibulae by connective tissue fibres (proximal type). The cartilaginous fetal anlage is either transformed to bone or catabolised during fetal life. Desmal ossification should play an important role in the growth of the corpus fibulae since no cartilage could be detected in juvenile and adult sheep. Since there are many similarities in the expression of the corpus fibulae between sheep, goat and fallow deer, this osteological characteristic may not be used for a rapid specific and simple animal species identification procedure.

Double-elevating osteotomy for late-presenting infantile Blount’s disease

We reviewed 34 knees in 24 children after a double-elevating osteotomy for late-presenting infantile Blount’s disease. The mean age of patients was 9.1 years (7 to 13.5).

All knees were in Langenskiöld stages IV to VI. The operative technique corrected the depression of the medial joint line by an elevating osteotomy, and the remaining tibial varus and internal torsion by an osteotomy just below the apophysis. In the more recent patients (19 knees), a proximal lateral tibial epiphysiodesis was performed at the same time.

The mean pre-operative angle of depression of the medial tibial plateau of 49° (40° to 60°) was corrected to a mean of 26° (20° to 30°), which was maintained at follow-up. The femoral deformity was too small to warrant femoral osteotomy in any of our patients. The mean pre-operative mechanical varus of 30.6° (14° to 66°) was corrected to 0° to 5° of mechanical valgus in 29 knees. In five knees, there was an undercorrection of 2° to 5° of mechanical varus. At follow-up a further eight knees, in which lateral epiphysiodesis was delayed beyond five months, developed recurrent tibial varus associated with fusion of the medial proximal tibial physis.

Ankle instability after vascularized fibular harvest for tumor reconstruction

BACKGROUND

The vascularized fibular graft is an important tool in the reconstruction of defects caused by resections of orthopedic tumors. Children often undergo this form of reconstruction, but there is little information about the complications after vascularized fibular graft harvest in this age group.

METHODS

We present a series of 32 patients who underwent this procedure to reconstruct an extremity in our institution. There were 12 children and 20 adults.

RESULTS

The residual distal fibula was significantly longer in adults as compared with children (P < .048). Among children, 3 of 11 undergoing the procedure developed ankle instability, in distinction to adults, none of whom developed this complication (P < .041). This reflects a disruption of normal ankle function that develops in skeletally immature patients with a short residual fibula but not in patients with a longer residual fibula (P < .008). When the sum of patient age in years and residual fibula length in centimeters was less than 16, 3 of 6 patients developed deformity, in contrast to no deformity developing in the remaining 23 when the sum was >16 (P < .004). Adults were more likely to develop pain than instability.

CONCLUSIONS

Our series suggests that children with an age-length sum <16 should be considered for prophylactic tibiofibular synostosis creation.

[Diagnostic image (182). A neonate with a bend in one lower leg. Posteromedial bowing of tibia and fibula]

A preterm girl was born with posteromedial bowing of the left lower leg, and dorsiflexion and calcaneovalgus position of the left foot. The bend reduced spontaneously.

Histologic examination of bone development in juvenile chimpanzees

The purpose of this study is to determine whether histologic skeletal development in chimpanzees (Pan troglodytes) differs from that in humans. Currently, minimal quantitative data are available on the bone histology of great apes. In addition to providing baseline data on juvenile chimpanzee bone histology, the data generated by this study have potential applications for studying the comparative development between chimpanzees and humans and other primates, as well as investigating the evolution of human bone development, differences in development among limb elements, and differences in histology related to locomotor function. The study sample includes thin sections from the femoral, tibial, and fibular midshafts of 13 chimpanzees originally prepared by Kerley ([1966] Tulane Stud. Zool. 13:71-82) as part of a study on skeletal age changes in the chimpanzee. Twelve juveniles, ranging in known age from 2-15.3 years, and one adult, with a known age of 35 years, are represented. For each specimen, numbers of osteons, osteon fragments, and non-Haversian canals were counted, and percent lamellar bone was estimated. Results were compared with data extracted from Kerley ([1965] Am. J. Phys. Anthropol. 23:149-164) on a juvenile human sample. Results indicate that juvenile chimpanzees and humans exhibit similar age-related changes in histologic variables. However, age is not as strong a predictor of variation in microstructural variables in chimpanzees as it is in humans.

A randomized, controlled lower leg growth study of vitamin D supplementation to healthy children during the winter season

BACKGROUND

The deceleration of longitudinal growth in children during winter occurs simultaneously with a decrease in the number of daylight hours and a reduction in vitamin D status. Due to worries about deleterious effects on bone of a relative insufficiency, vitamin D supplementation to healthy children has been suggested.

AIM

To see whether supplementation of vitamin D to healthy children during winter affects seasonal growth.

SUBJECTS AND METHODS

Twelve girls and eight boys aged 6.2-13.7 (mean 9.8) years, all healthy, were enrolled in a double-blind, randomized, placebo-controlled cross-over study with two 4-week treatment periods and 2-week run-in and wash-out periods. Vitamin D(3) 600 IU was given in one tablet ABCDin daily. Knemometry of the right lower leg was performed on the first and last day of each period.

RESULTS

Lower leg growth rates (mean +/- SEM) during placebo and vitamin D(3) administration were identical: 0.28 +/- 0.04 mm per week (p = 0.94, t = 0.1, 95% CI: - 0.12-0.13 mm per week).

CONCLUSION

Supplementation with vitamin D(3) 600 IU day(-1) to healthy children during winter may not improve seasonal growth. Therefore, supplementation may not be recommended on the grounds of concerns about growth; however firm conclusions await randomized long-term studies.

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%.

Observations on the cause of bowlegs in achondroplasia

An analysis of 148 radiographs of the tibia during skeletal maturation in patients with achondroplasia was performed. The fibula was always longer than the tibia. The distance between the proximal tibial and fibular physis was less than normal throughout growth. The distance between the distal tibial and fibular physis was normal in childhood and became increasingly greater during growth. Tibia varus increased during growth, and there was a particular increase in distal tibia varus toward the end of growth. The altered growth characteristics of the bones suggest a formulation of cause of bowlegs in achondroplasia.

Modified Ertl osteomyoplasty for terminal overgrowth in childhood limb deficiencies

Terminal overgrowth continues to be a problem in children with amputations. Many operative treatment methods have been proposed, but no consensus has been reached regarding the procedure of choice. Six patients underwent a modified Ertl procedure for the treatment of terminal overgrowth in seven residual lower limbs (one bilateral). All these patients were skeletally immature. The average age at index procedure was 5 years 9 months (range, 1 year 3 months-6 years 11 months). Revision was necessary in four patients, with one patient requiring two revisions of the same limb. The modified Ertl osteomyoplasty can be performed safely in children, but appositional overgrowth may continue through the tibiofibular synostosis. The procedure is not recommended in skeletally immature patients.

Altered fibular growth patterns after tibiofibular synostosis in children

BACKGROUND

Iatrogenic synostosis of the tibia and fibula following an operation on the leg in a child has been reported rarely in the literature, and the effects of this complication on future growth, alignment, and function are not known. This is a retrospective case series, from one institution, of crossunions of the distal parts of the tibia and fibula complicating operations on the leg in children. The purpose is to alert surgeons to this possible complication.

METHODS

The senior author identified eight cases of iatrogenic tibiofibular synostosis seen in children since 1985. The patients had various diagnoses and were from the practices of four pediatric orthopaedic surgeons. Synostosis developed in six patients after osteotomies of the distal parts of the tibia and fibula, in one after internal fixation of distal tibial and fibular metaphyseal fractures through a single incision, and in one after posterior transfer of the anterior tibialis tendon through the interosseous membrane combined with peroneus brevis transfer to the calcaneus. Medical records were reviewed, and preoperative and follow-up radiographs were analyzed for changes in the relative positions of the proximal and distal tibial and fibular physes and in the alignment of the ankle.

RESULTS

Five patients were symptomatic after crossunion; they presented with prominence of the proximal part of the fibula, ankle deformity, or ankle pain. Three patients were asymptomatic, and a synostosis was identified on routine follow-up radiographs. Intraoperative technical errors caused two of the crossunions; the cause of the others was unknown. Following tibiofibular synostosis, growth disturbances were noted radiographically in every patient. The normal growth pattern of distal migration of the fibula relative to the tibia was reversed, resulting in a decreased distance between the proximal physes of the tibia and fibula as well as proximal migration of the distal fibular physis relative to the distal part of the tibia. Shortening of the lateral malleolus led to greater valgus alignment of the ankle.

CONCLUSIONS

Tibiofibular synostosis can complicate an operation on the leg in a child. After crossunion, the normal distal movement of the fibula relative to the tibia is disrupted, resulting in shortening of the lateral malleolus and ankle valgus as well as prominence of the fibular head at the knee. The synostosis also interferes with the normal motion that occurs between the tibia and fibula with weight-bearing, potentially leading to ankle pain.

Reconstruction of the lateral malleolus using a reverse-flow vascularized fibular head: a case report

We report a case of a 7-year-old girl in whom a vascularized fibular head with preserved epiphyseal and metaphyseal blood supply was used to reconstruct the missing lateral malleolus. Two-year follow-up showed good bony stability and growth potential of the transplanted epiphyseal plate.

[Percutaneous epiphyseodesis for treating limb length inequality in children --results after termination of growth]

Results of percutaneous epiphyseodesis for limb length egalization in 25 children (10 girls and 15 boys) after termination of growth are presented. Mean age at the surgery was 12.9 years (range 10.9-14.4 years), mean limb length discrepancy 4.3 cm (range 2-10 cm), mean follow-up was 50 months (range 14-86 months). In 17 cases distal femoral epiphyseodesis was done, in 7 cases distal femoral, proximal tibial and fbular and in 1 case only proximal tibial and fibular epiphyseodesis was performed. In 13 cases CT served to assess the area of removed physis. Among complications knee hemarthrosis was encountered twice and once subcutaneous hematoma of the lower leg occurred. At the final follow-up full range of motion in the knee and correct axial alignment was observed in all cases. Residual limb length discrepancy was 1.3 cm (range 0-4 cm). Between 20 and 60% of total area of the physis was destroyed. Yearly rate of femoral bone growth inhibition was the same in patients with 27% and 40% of physis removed.

Ilizarov lengthening in centralized fibula

Tibial hemimelia often produces major limb length problems (1,6,9,15) as well as foot deformity. The decision to perform reconstructive surgery depends on the expected leg-length discrepancy, the anomalies of the foot, and the status of the knee (4,6,8,15). Congenital bone deficiencies usually have a constant rate of growth inhibition (8), and leg lengthening is often associated with more complications (5,13). The complication rate is also increased with the increased leg-length discrepancy (5). In tibial hemimelia with functioning quadriceps (types I and II) and a functional foot, centralization of the fibula onto the talus and synostosis with the proximal tibia is an accepted reconstructive procedure (1,4,6,7,9,15). However, when the transplanted fibula produces a functional limb for the patient, the correction of leg-length inequality would be a challenge. This is a report of such a case.

Prenatal ultrasonographic diagnosis of posteromedial bowing of the leg: two case reports

Congenital posteromedial bowing of the leg was prenatally detected in two pregnancies, at 20 and 31 weeks of gestation. Posteromedial bowing is a rare anomaly of unknown etiology. The prenatal course, monitored by ultrasonography, and the postnatal clinical and radiographic outcomes are discussed and show a complex differential diagnosis. The initial postnatal therapy is conservative. Leg length discrepancy can eventually be treated by lengthening or epiphysiodesis on the contralateral side.

Chronic recurrent subluxation of the peroneal tendons in a pediatric patient. Surgical recommendations

Numerous surgical and non-operative approaches have been used to treat chronic recurrent subluxation of the peroneal tendons in adult athletes. There have been no published reports of surgical repair in children. In this report on a skeletally immature patient a modification of the Chrisman-Snook procedure (previously described for lateral ligament reconstruction) is described to correct recurrent subluxation of the peroneal tendons, child.

Role of bone bark during growth in width of tubular bones. A study in human fetuses

The morphologic features of bone bark, a structure surrounding the distal and proximal ends of long bones, were studied in the distal femur, proximal tibia, and proximal fibula of 77 spontaneously aborted human fetuses varying in gestational age from 10 to 20 weeks. Standard histologic techniques used in addition to in situ immunohistochemical staining allowed the examination of the structure of the bone bark and localization of Types 1, 2, and 3 collagens at different gestational ages. The bone bark was shaped like a cylindrical sheath of bone lamellae of varying thickness. The epiphyseal end of the bone bark, known as the groove of Ranvier, was covered outwardly by a fibrous layer and inwardly by the epiphyseal cartilage and contained mesenchymal cells, chondroblastic precursor cells, and densely packed cells differentiating into osteoblasts. Neither the cell density in the groove nor the thickness of the bone bark were identical circumferentially, indicating an unequal growth in width. In addition, the presence of periosteal apposition and endosteal resorption of the bone bark on one side and of endosteal bone deposition accompanied by periosteal resorption of the bone bark on the opposite side support the concept of a spatial drift of bones. These observations furnish histologic proof that groove and bone bark, although assuring an equal growth in length, contribute to an unequal and eccentric growth in width.

Distal tibiofibular diastasis secondary to osteochondroma in a child

An 18-month-old girl with a distal tibiofibular diastasis secondary to an osteochondroma was seen with a valgus deformity of the ankle. The patient underwent operative excision of the osteochondroma at the age of 2 years. At 13-year followup there was resolution of the diastasis, and the patient was free of symptoms. Early excision obviates the need for complex reconstructive surgery to correct ankle deformity later.

Growth after extendible endoprosthetic replacement of the distal femur

We report our results in 24 children with malignant primary bone tumours of the distal femur treated with a Stanmore extendible endoprosthesis (SEER). This consists of a femoral component that can be lengthened, a constrained knee and an uncemented sliding tibial component which crosses the proximal tibial physeal plate perpendicularly. The average age of the patients at diagnosis was ten years and the mean follow-up was 4.7 years (2.5 to 7.9). The mean growth of the affected tibia was 76% (18 to 136) and of the fibula 83% (15 to 750) of the growth of the unaffected limb. Measurement of growth arrest lines showed that the mean growth of the proximal tibial physis on the affected side was 69% (43 to 100) of that of the normal side. The great variability in the growth of the physis cannot yet be explained.

Growth and growth prediction of the fibula

Growth prediction data and graphs have not been available previously for the fibula. In this report, this information is wholly derived from a longitudinal radiographic study of growth in children. Teleradiographs of the tibia and fibula in 244 children (123 boys and 121 girls) were made at 6-month intervals from age 7 until skeletal maturity. Length measurements determined the growth of the fibula. The subjects were healthy well nourished middle class Americans, mostly of Northwest European descent. Growth occurring at the fibular growth plates was determined by the relationship to the tibia. The contribution of the proximal and distal growth plates to total length was determined by multiplying the percentage of growth occurring at each age by the longitudinal growth remaining. Graphs then were constructed using the logarithmic adjustment of Colin Moseley to produce a straight line graph. The proportion of growth occurring at the proximal and distal growth plates is not equal. More growth occurs at the proximal growth plate of the fibula than at the proximal growth plate of the tibia. The overall growth contribution of the proximal fibular growth plate is 61% compared with 57% for the proximal tibia. The graphs provided allow accurate prediction of fibular growth.

Varus and internal rotational deformity of the ankle secondary to distal tibial physeal injury

Nine children who sustained Lauge-Hansen's supination-inversion injury of distal tibial physeal injury with intact distal fibular physis, were followed until their maturity. The average varus deformity was 39 degrees (maximum, 80 degrees) with 23 degrees of internal rotational deformity. The longitudinal growth of the fibula was retarded compared with opposite normal leg. There was early closure of the medial distal tibial physis, gradual upward migration of medial malleolus, and eventually medial subluxation of the ankle; these resulted in gradual varus and internal rotational deformities of the injured ankle. It is thought that the resultant disabling deformity of ankle should be prevented by any means, though presently there are no available effective methods of treatment. It is suggested that the repeated corrective osteotomy should be carried out before epiphyseal deformity of the distal tibia and subluxation of the ankle joint develop.

Experimental vascularized bone transplantations

The postoperative hypertrophy of the vascularized fibula graft is of particular interest. In order to clarify the etiology of the hypertrophy, we conducted experimental projects on vascularized bone grafts using fluorochrome bone labelings, histomorphometry and measurement of blood flow in rats and rabbits. In the murine vascularized tibio-fibula graft for bone defects of the tibia, where mechanical stress to the graft can be expected, cross-sectional bone growth was maintained with acceleration of new bone formation and an alteration of growth direction at 3 weeks after the transplantation. In vascularized bone grafts where no mechanical stress to the graft is expected, more bone resorption was seen than bone formation. In the murine tail bone graft to a bony defect of the femur, the cancellous bone gradually disappeared, and the trabeculae took on an architecture characteristic of the femur. This process slowly transforms the graft into a femur with the morphologic features of a long bone. These results suggested that remodeling of the graft corresponding with the changes in the dynamic environment was accompanied by adequate resorption. The cross-age transplantation of vascularized tibio-fibula grafts in rats showed that the younger the donor, the faster the hypertrophy. Age is one of the important factors affecting remodeling of the vascularized bone graft. The blood flow of the grafted bone in the rabbits increased immediately after the transplantation as a reaction to surgery. Thereafter the blood flow of the graft may depend on the biological demands for new bone formation in adapting to the biomechanical environment of the recipient site.

Normal maturing distal tibia and fibula: changes with age at MR imaging

PURPOSE

To describe the normal appearance of the maturing distal tibia and fibula at magnetic resonance (MR) imaging.

MATERIALS AND METHODS

The authors retrospectively studied 50 MR examinations of patients aged 2 months to 21 years, dividing them into six developmental groups according to the appearance of the distal tibia and fibula. Epiphyseal ossification, physeal closure, and the signal characteristics of physeal cartilage were evaluated.

RESULTS

Distal tibial epiphyseal ossification and physeal closure both began anteromedially and usually occurred earlier than in the fibula. The tibial physis developed an anteromedial undulation (Kump hump) before closure; volume averaging at the Kump hump simulated premature closure. The cartilaginous epiphysis had a lower signal intensity than the physis on T2-weighted images. The physis was most conspicuous on gradient-recalled-echo and fat-suppressed spin-echo proton-density-weighted images.

CONCLUSION

Developmental cartilaginous and bone changes in the distal tibia and fibula follow a definite pattern and are well seen at MR imaging.

Recurrent medial ankle instability: the result of distal fibular growth arrest

Recurrent medial ankle instability is an uncommon clinical entity. A case that resulted from a distal fibular physeal arrest is described. Symptoms resolved after a one-stage fibular lengthening.

Bilateral distal fibular growth abnormalities in a dog

A 6-month-old Shetland Sheepdog was examined because of a valgus deformity of the left hind limb. Six weeks earlier, the dog had developed a fracture of the distal portion of the right fibula, which was successfully treated by use of external coaptation. Radiography revealed valgus deformity centered at the left distal tibial and fibular physes. Radiographically, the left fibula was 1.5 cm shorter than the left tibia, and the right fibula was 1.3 cm shorter than the right tibia. A distal tibial closing wedge ostectomy was performed to correct the left hind limb angular deformity. The angular deformity was believed to have developed because of abnormal growth of the left distal fibular physis. It is likely, considering the displacement of the right fibular head, that the dog also had premature closure of its right distal fibular physis. The fracture of the right fibula may have prevented development of an angular deformity of the right hind limb.

[Age-dependent development of the long hollow bones in white New Zealand meat rabbits and chinchilla-hybrid laboratory rabbits]

The age dependent development of the long bones' diaphyses (humerus, os femoris and os tibiofibulare) was examined macroscopically, morphometrically and histologically using 15 White New Zealand Rabbits (WN) and 15 Chinchilla-Bastard-Experimental-Rabbits (Chbb) in 5 different age groups. The main growth of bone occurs in the first three months of life. The remodelling from juvenile to adult bone began in the period from the 4th-12th week. The different bones show various characteristic remodelling zones for each localization. Until the 12th week the resorption of juvenile bundled bone predominates. Afterwards an increasing bone formation by osteal bone can be observed. The bone growth is terminated between the 17th and 33rd week. The os tibiofibulare in both breeds represents the major part of the compact bone area on the whole cross-section area. Principally the bone-remodelling process proceeds equally in both breeds. Breed dependent differences in the adult bone are seen in the construction of the circumferential lamellae. These are formed considerably more irregularly by the Chbb-rabbits than by the WN-rabbits.

Roentgen stereophotogrammetric short-term analysis of growth rate in children operated for Crohn's disease

Roentgen stereophotogrammetry is a new method for short term analysis of growth rate. Growth is measured over the growth zone in the distal fibula and is a fraction of the total statural growth. Normal growth rate in the distal fibula is about 15 micrograms/day at a total growth rate of 5 cm/year. The method was used to follow growth six months before and six months after surgery in six growth retarded children with Crohn's disease. Growth rate increased significantly (p less than 0.01) within three months after surgery from 5.8 microns/day before operation to 15.8 microns/day three months after operation and six months postoperatively had reached 18.0 micron/day. Improved growth could be recorded as early as four weeks after operation. The Roentgen stereophotogrammetric analysis (RSA) gives a unique possibility to follow short-term changes in growth rate in children with disturbed growth and to use growth rate as a quick assessment of response.

[The development of the torsion angle of the tibia-fibula unit in various age groups]

We studied the torsion angle of the tibiofibular unit in both lower legs of 1588 schoolchildren of both sexes (998 girls and 590 boys), aged between 3 and 18 years divided into four age groups. The torsion angle of the tibio-fibular unit progressively increases with age. Stable values were measured only in the 11-15 years age group. Statistically significant differences of the torsion angle between one lower limb and the other were detected in the girls of the 6-10 and 11-15 age groups, and in the boys of the 6-10 age groups.

Postnatal epiphyseal development: the distal tibia and fibula

At birth, the distal tibial physis is a transverse structure. However, as the tibia enlarges diametrically and the epiphyseal ossification center matures, the physis becomes increasingly undulated, with peripheral lappet formation. The anteromedial area is the first to develop undulation (Poland's hump). This should not be misinterpreted as an injury or premature epiphyseodesis subsequent to trauma. The tibial secondary ossification center forms within the central epiphysis. The medial margin is irregular and may have peripheral foci of ossification. Between the ages of 7 and 8 years, this secondary center extends into the medial malleolus, reaching the distal tip during adolescence. The malleolar tip may develop accessory ossification. Physiologic epiphyseodesis begins over the medial malleolus and then extends laterally, a pattern of closure that affects fracture patterns (e.g., the fracture of Tillaux). The distal fibular physis also begins as a transverse structure that becomes undulated and has extensive peripheral lappet formation. This physis usually becomes level with the articular surface of the distal tibia after the first year. Enchondromalike extensions of the physis into the metaphysis are common. Accessory ossification may develop at the distal end.

Two rare developmental defects of the lower limbs with confirmation of the Lewin and Opitz hypothesis on the fibular and tibial developmental fields

We report on two unrelated patients with malformations of the lower limbs. One had a unilateral apparent doubling of the volume of the femur with distal bifurcation, shortness of the tibiae, absence of fibulae, and lateral ray deficiencies of both feet. The other had a partial duplication of the distal left femur, hypoplasia and proximal dislocation of the ipsilateral tibia, syndactyly of the right 1st and 2nd toes, and preaxial polydactyly of the left foot. This report supports the hypothesis of Lewin and Opitz on the presence of two distinct fields of development: the fibular and the tibial.

[Acute infantile osteomyelitis]

In infants acute haematogenous osteomyelitis presents with few and subtle clinical signs. Only early diagnosis and proper treatment of this orthopedic emergency are able to prevent late deformities. Delay in diagnosis, persistence in apparently not effective conservative therapy and inadequate surgery lead to ugly and severe deformities, of which the corrective treatment is a heavy burden for the child and its parents.

Longitudinal growth of the distal fibula in children with slipped capital femoral epiphysis

The longitudinal growth rates of the distal fibula were measured, using a roentgen stereophotogrammetric method, in 32 children treated for slipped capital femoral epiphysis and compared with growth rates in a series of normal children. The growth rates in patients were similar to the growth rates in normal children, in both boys and girls. However, at the time of slippage, 13 patients had a body height exceeding the normal value by greater than 1 SD, indicating an above-average growth rate before slippage. This pattern was found in one boy whose distal fibular growth rates were measured both before and after slippage. In conclusion, there are indications that the skeletal growth rate is slightly accelerated before slippage and more normal after slippage.

The role of the epiphyseal and metaphyseal circulations on longitudinal growth in the dog: an experimental study

An experimental model using the immature canine proximal fibular epiphysis was developed to isolate and investigate the effects of the epiphyseal and metaphyseal circulations on longitudinal growth. Experimental constructs studied the epiphyseal circulation, the epiphyseal and metaphyseal circulations, a devascularized growth plate, and a control group. Twenty-four limbs were studied by serial x-ray films and microangiographic and histologic analyses at time of death, 24 weeks after surgery. The data from this preliminary study show that both metaphyseal and epiphyseal circulations are necessary for predictable longitudinal growth.

Heterotopic microvascular growth plate transplantation of the proximal fibula: an experimental canine model

The reconstructive potential of microvascular transplantation of skeletal growth plates was investigated through heterotopic transfers. The distal radius was resected in two series of puppies of a known large breed and substituted with a microsurgically revascularized transplant from the proximal fibula. Evaluation was conducted through serial roentgenograms, goniometric registration of joint mobility, volume measurements, histology, and fluorescent bone labeling. In the first series, development of neuropathic-like destruction of the weight-bearing graft ensued in the majority of the animals. In the second series, prolonged protection from weight bearing inhibited this destruction and resulted in hypertrophy of the revascularized epiphyseal end of the transplant but clearly reduced longitudinal growth, with only one transplant exhibiting longitudinal growth that exceeded 50 percent of the value for the control. This experiment demonstrates that skeletal growth plates possess a capacity for hypertrophy under the influence of increased loads. Whether this adaptability is sufficient to allow microvascular transplantation of growth plates to become a clinically useful procedure in children remains unclear. Further laboratory investigations are mandatory prior to clinical application of microvascular transfers of epiphyseal growth plates.

Fractured fibulae in broiler fowls

Fibular diaphyseal fractures were identified bilaterally or unilaterally in 15 broilers aged between 13 and 105 days. Incomplete cortical defects were also identified on radiographs in a further 8 birds. Fractures and incomplete defects always occurred at the Tuberculum M. iliofibularis of fibulae. The character of bone at this site differed from bone elsewhere in the diaphysis. Following fracture, cartilaginous callus united the diaphyseal segments and pseudarthrosis or fibrous non-union were common sequelae. The concept that fibular fractures in broilers are always a consequence of abnormal proximal tibiotarsal curvature is not supported by this study. It is suggested that differential growth of the paired crural bones is of primary importance.

Longitudinal growth rate of the distal tibia and fibula in children

In 61 children (30 boys and 31 girls), the growth rates in the distal tibia and fibula were recorded by use of a roentgen stereophotogrammetric technique. The average observation time was about one year and seven months. The growth rates were correlated with chronologic and skeletal age. Adjusting for skeletal age did not significantly change the average growth rates or the scattering of the values. The mean growth rate and the remaining growth from about nine years of age in the boys and eight years of age in the girls were calculated for separate age groups. In the distal tibia in the boys and the girls, the average growth rate decreases from a plateau of about 11 and ten years of age, respectively. Decreasing growth rates were found somewhat later in the distal tibia than in the distal fibula in both the boys and the girls. The growth rates were close to zero at about the same time in the distal tibia and fibula in both sexes. In determining the remaining growth, the large biologic variability indicates the importance of serial measurements on the individual patient. The individual growth charts, together with clinical and radiographic estimation of maturity, provide a guideline for treatment of a patient with growth disturbance of the distal tibia and fibula.

Changes in tibiofibular relationships due to growth disturbances after ankle fractures in children

We analyzed the longitudinal growth of the distal tibial and fibular physes and the longitudinal displacement of the distal metaphysis and epiphysis of the fibula relative to the distal metaphysis and epiphysis of the tibia during growth using a roentgenstereophotogrammetric technique in eight children: six with a traumatic growth disturbance in one or both of the distal tibial and distal fibular physes and two with a normal ankle. In the normal ankles the distal fibular metaphysis moved distally in relation to the distal tibial metaphysis and the growth in the distal fibular physis was slower than that in the distal tibial physis. Growth arrest in the distal fibular physis and continued growth in the distal tibial physis resulted in distal displacement of the fibular metaphysis relative to the tibial metaphysis, probably due to traction on the distal ligaments of the fibula or more rapid growth in the proximal fibular physis than in the proximal tibial physis, or both. Valgus deformity of the ankle developed when the growth of the distal tibial physis exceeded the distal sliding of the fibula, as shown by the stereophotogrammetric analyses and orthoroentgenograms. Growth arrest in the distal tibial physis and continued growth in the distal fibular physis resulted in proximal sliding of the fibula, as shown by the roentgenstereophotogrammetric analyses and serial orthoroentgenograms. This mechanism compensated to some extent for the overgrowth of the fibula. Simultaneous growth arrest in both the distal tibial and the distal fibular physis was associated with movement of the distal end of the fibula in a distal direction relative to the tibia, probably due to the more rapid growth in the proximal fibular physis than in the proximal tibial growth plate. Therefore, growth arrest of the distal tibial or fibular physis may result in either proximal or distal sliding of the fibular metaphysis in relation to the tibial metaphysis. Probably growth arrest in the distal fibular physis has a less favorable prognosis than arrest in the distal tibial physis, because after tibial arrest proximal sliding of the fibula may compensate for overgrowth of the fibula better than distal sliding of the fibula can compensate for fibular arrest and overgrowth of the tibia.

Congenital posteromedial bowing of the tibia and fibula

Patterns of growth and development are presented for 33 patients with congenital posteromedial bowing of the tibia and fibula. The bowing is accompanied by shortening of the tibia and fibula, an initial calcaneovalgus deformity of the foot, and a decrease in ankle motion that does not improve with age. In general, the greater the initial bowing, the greater the ultimate extremity length discrepancy. The proportionate length differences between the normal and the bowed tibiae remained stable after the age of 12 months. This allowed a projection of anticipated extremity length discrepancy at maturity and a determination of the proper treatment. At birth the bowing varied from approximately 25 to 70 degrees, and at maturity the absolute tibial length discrepancies varied from 3.3 to 6.9 cm. Both the posterior and the medial components of the bow became markedly reduced with increasing age, but a mild residual medial portion of the bow remained. Soft tissue enlargement was observed in the posterior aspect of the affected legs in early life and developed to a relative muscle atrophy in later years.

[Experimental study of vascularized fibular grafting including the epiphyseal growth plate--autogenous orthotopic grafting]

Advancements of microsurgery opened up a new horizon in various facets of surgery. Vascularized bone grafting is one of them and promised viable bone grafting with superb results. Whether this bone grafting along with the epiphyseal growth plate yields continuous bone growth is a matter of great concern and the purpose of the present study. Thirty-nine puppies were used for the experiment, and they were divided into two groups. The proximal portion of the fibula was resected with the popliteal artery and vein including their branches to the epiphysis and the metaphysis, and then, the fibula was returned to the original place and fixed with two Kirschner wires. In group 1, the artery and vein were anastomosed with 10-0 Nylon sutures under operative microscope. In group 2, the bone was treated in a same fashion, but without vascular anastomosis. The roentgenological and histopathological changes were sequentially studied in the both groups. Results were summarized as follows: In group 1, 13 dogs were followed until the epiphyseal closure completed. In two dogs, the treated fibula was of equal length with the non-treated opposite fibula, whereas in five dogs there was slight hypogrowth (average 1.8 mm) and in six dogs there was slight overgrowth (average 2.2 mm). Otherwise, The roentgenological appearance was essentially normal. There was no significant difference in the histopathology of the epiphyseal plates in the treated and the non-treated fibulas. In group 2, all the treated fibulas failed to show epiphyseal growth. Roentgenologically destruction and absorption appeared as early as in the first and second week postoperatively, followed by a fracture line through the metaphysis with displacement and nearly complete absorption of the grafted bone. Histopathological findings consisted of early destruction of the growth plate and early necrosis of the bone marrow as well as the bone trabeculae of the epiphysis, metaphysis and diaphysis. Some reparative new bone formation was noted in the grafted area. In conclusion, the results of the experiment showed the possibility of normal bone growth when a bone is grafted with its epiphyseal growth plate provided the vascular supply to them is reconstructed.

Pathogenesis of idiopathic clubfoot

During embryonic development the foot passes consecutively into three different positions: (1) when the embryo is in the 15-mm stage the foot is in a straight line with the leg (initial position); (2) by 30 mm the foot passes to a marked equinovarus-adductus position (embryonic position); and (3) finally, by 50 mm, the foot changes to a slightly equinovarus adductus position (fetal position). The morphologic and structural changes of the foot from the initial to the embryonic position result from the growth of the distal ends of the fibula and of the skeletal elements of the lateral foot during the "fibular phase" of rapid growth (from 21 to 30 mm). The changes from the embryonic to the fetal position are due to the growth of the distal ends of the tibia and of the skeletal rays of the medial foot during the "tibial phase" of rapid growth. Many known noxious industrial chemicals (and probably many more yet to be recognized) have antimitotic and antimetabolic action. Depending on the characteristics of the chemical, some produce permanent arrest and therefore congenital malformation, while others cause temporary growth arrest, e.g., Harris transverse lines, which is frequently unnoticed. Finally, some substances, e.g., glucocorticoids, cause a growth delay. Depending on the developmental stage of the embryo and the duration of the action of the noxious substance, growth arrest of the foot occurs in an attitude close to the embryonic position. If it occurs at the end of the fibular phase and during the first half of the tibial phase, the foot will remain in a permanent and marked equinovarus-adductus position, and a severe clubfoot will result. When a noxious chemical acts only during the last half of the tibial phase, a mild, flexible clubfoot will result because by this stage most parts of the embryonic components have been corrected. If it occurs at the end of the tibial phase, a simple metatarsus adductus deformity will persist. As soon as the growth arrest phase ends, all of the skeletal elements begin to grow again, but only from a later point in development. If the growth disturbance occupies the entire tibial phase, neither the tibia nor the skeletal elements of the foot would be able to complete a rapid growth spurt, since by that stage the moment genetically programmed for such growth has already passed. The morphology of the deformities existing in the clubfoot corresponds to the morphologic program of the embryonic foot.(ABSTRACT TRUNCATED AT 400 WORDS)