Limb length discrepancy and congenital limb anomalies in fibular hemimelia

Characteristics of terminal hemimelia: What is the difference between terminal hemimelia and classic fibular hemimelia?

Purpose

Fibular hemimelia has denoted a spectrum of postaxial longitudinal deficiency with fibular aplasia/hypoplasia; the term "terminal hemimelia" is reserved for patients with postaxial longitudinal deficiency having a normal fibula. We aimed to delineate the characteristics of terminal hemimelia.

Methods

In total, 30 patients with postaxial longitudinal deficiency who had a normal or hypoplastic fibula and visited our institution between 1992 and 2022 were reviewed. Patients were divided into terminal hemimelia and classic fibular hemimelia groups, and their demographic characteristics and clinical and radiographic findings were compared.

Results

Femoral shortening, knee valgus, and tibial spine hypoplasia were less common in terminal hemimelia (n = 13) than in classic fibular hemimelia (n = 17) (p = 0.03, p < 0.001, and p = 0.003, respectively). None of the patients in the terminal hemimelia group exhibited knee instability, whereas 12% of patients with classic fibular hemimelia did. Ball-and-socket ankle and absence of lateral rays were commonly observed in both groups. However, tarsal coalition was observed less frequently in terminal hemimelia (p = 0.004). All terminal hemimelia patients exhibited a painless plantigrade foot without ankle instability. Despite limb-length discrepancy at maturity averaging 40.4 mm for terminal hemimelia and 67.0 mm for classic fibular hemimelia (p < 0.001), patients with terminal hemimelia, except for one, exhibited > 20 mm of limb-length discrepancy. However, 46% of them underwent limb-length equalization procedures, mostly single-stage tibial lengthening, at a mean age of 11.2 years.

Conclusion

Terminal hemimelia may present with a milder phenotype than classic fibular hemimelia. It mainly overlaps with the symptoms of fibular hemimelia below the ankle joint and manifests as limb-length discrepancy. However, a considerable number of patients with terminal hemimelia required limb-length equalization procedures, for example single-stage tibial lengthening.

Level of evidence

level IV.

Foot Oligodactyly as the Main Dysplasia in Children

Introduction Foot oligodactyly is usually associated with fibular insufficiency or cleft foot syndrome. A foot with a reduced number of rays may occasionally have an isolated dysplasia. Methods We reviewed the clinical notes and X-rays of six children with oligodactyly, having a normal development of the tibia and fibula. Clinical evaluation recorded the plantigrade or deviated foot, appropriate shoe wear, and aesthetic presentation of barefoot children. Radiological examination revealed missing or hypoplastic bones in the foot, the presence of other deformities, and leg length discrepancy (LLD) of the affected limb. Results On clinical evaluation, all children except one had a plantigrade foot with normal shoe wear; the lesion was not spotted in three of them unless informed of the presence of the dysplasia. Radiological examination in four of them revealed the absence or hypoplasia of the navicular, with a normal shape of the first metatarsal. Calcaneocuboid joints were normal in five of them; LLD was the main problem in three children. The girl with bilateral oligodactyly presented as a normal child. Conclusion Oligodactyly may present as an isolated dysplasia. LLD in these patients, which is less severe than in children with fibular or tibial insufficiency, is the main issue that requires surgical management in later life. Prenatal diagnosis of oligodactyly as an isolated dysplasia is an important feature for appropriate counseling of parents.

Does Focal Osteolysis in a PRECICE Stryde Intramedullary Lengthening Nail Resolve after Explantation?

Concerns surrounding osteolysis near and around the modular junction of a stainless-steel intramedullary lengthening rod prompted a manufacturer recall from the United States market in early 2021. These actions were preceded by similar steps taken in Europe. A concomitant review of stainless-steel lengthenings at our institution demonstrated signs of adverse tissue reaction including periosteal reaction and osteolysis at the modular junction and/or male-sided locking screws. Nearly half of our patients presented with these findings on radiographic images. At the time of the previous review, only half of the nearly 60 implanted stainless-steel devices met a 6-month follow-up. At this juncture, many patients have had their devices explanted. Given the suspected adverse tissue reactions caused by a component of the internal device, we sought to examine the rate of osteolysis post-explantation following removal of a stainless-steel nail. We reviewed a consecutive series of patients who underwent implantation of a stainless-steel limb lengthening device in the femur and/or tibia at a single institution between December 2018 and December 2020. Patients were included if their device was explanted. Periosteal reaction and osteolysis was classified according to a novel and validated classification system, as analyzed by five fellowship-trained surgeons. In addition, changes observed prior to explantation were tracked post-explantation to assess for resolution. The incidence of periosteal reaction and osteolysis prior to explantation was 22/57 (39%) and 15/57 (26%), respectively. Of the 15 patients with osteolysis pre-explantation, 14 patients’ implants were explanted. Of these, eight patients had available follow-up films. Two patients were identified as having partial osteolysis resolution at mean 1-year follow-up, while six patients were identified as having complete osteolysis at mean 18-months follow-up. Periosteal tissue reaction and osteolysis largely resolved following explantation in a subset of patients. These results provide further support to the claim that the stainless-steel device contributed to the changes seen. Further follow-up is warranted to examine the longer-term effects of adverse tissue reaction in this patient population.

Case report: Single-session double-Ilizarov lengthening technique in the treatment of a child with congenital fibular deficiency

BACKGROUND

Congenital fibular deficiency is a rare disease with a broad spectrum of deformities. Associated anomalies complicate the symptoms of patients and, consequently, individualized treatments that aim at normal function and acceptable appearance.

CASE PRESENTATION

We present a case of congenital femoral and fibular shortening in the right lower limb with foot anomaly at school age. The patient underwent limb lengthening procedure in a single session on the right femur and tibia at the same time using a double-Ilizarov frame. The functional and cosmetic of his right lower extremity achieved a good outcome. Complications were minimal except for the superficial infection. Treatment lasted for 9.2 months, allowing for returning the patient to functional activity as soon as possible.

CONCLUSION

A satisfactory result was obtained with limb lengthening in a single session using double Ilizarov external fixators in a school-aged patient with congenital fibular deficiency.

Embryology of the lower limb demonstrates that congenital absent fibula is a radiologic misnomer

The congenitally shortened limb (CSL) with fibular deficiency or absence has historically been graded by plain radiography, while associated cartilaginous and arterial soft tissue anomalies have been comparatively neglected. Consistent pathological evidence of remnant cartilaginous bodies in place of the fibula presupposes earlier existence of a preformed cartilaginous template of the fibula. In complete fibular radiographic absences, often associated with midline metatarsal deficiencies, the two usual nutrient arteries to the fibula fail to form, as they normally would have, around the (16-18 mm stage) sixth embryonic week. The histopathology of fallow persisting fibular anlagen, in association with missing arteries and retained primitive arteries, suggests the anlage is a dystrophic, but otherwise normally prefigured, cartilaginous scaffold of the fibula. Thus, the widely employed term absent fibula, which has been grounded in plain radiography, is a misnomer. Additionally, since the metatarsals missing in congenitally shortened limb are midline, the related term, fibular hemimelia, is similarly inaccurate. A new taxonomy, based on embryological principles rather than radiographic appearance alone, will promote limb dystrophism as a more accurate term combining arrested embryonic vascular development and congenitally shortened limb of the lower extremity.

The vascular origins of antero-medial tibial bowing in congenital fibular deficiency

Anteromedial bowing and shortening of the tibia are intrinsic features of limbs with congenital fibular deficiency (CFD). Tibial bowing occurs more frequently when the fibula is radiographically absent rather than deficient. The bowing has been attributed to rapid longitudinal growth of the tibial anlage coupled with anteromedial tibial bending moments of the posterior crural and lateral peroneal musculature unopposed in the absence of a fibular strut. Eccentric mechanical loading results in asymmetric mineral deposition and thickening of the diaphyseal cortex. Skeletogenesis depends upon an intimate interplay between the normally prefigured tibial cartilage anlage and beginning muscular contractile actions during initial vascularization of the anlage, while the embryonic limb vasculature is undergoing a series of transitions. A diaphyseal periosteal collar normally forms at the site of nutrient artery invasion and stabilizes the growing anlage. In CFD however, arteriography consistently reveals anomalous tibial nutrient arterial branches, which originate from a primitive axial artery rather than from the usual posterior tibial artery. These anomalous nutrient arteries enter the tibial shaft at the posterior aspect of the proximal metaphysis, establishing an eccentric bone collar. The developing vasculature of the embryonic limb is responsive to the then most metabolically active tissues. Disruption of the reciprocal relationship between the transitioning vasculature and the developing long bones is pivotal in producing the diverse skeletal malformations of the congenital short limb (CSL). Embryonic vascular dysgenesis contributes not only to the well-recognized congenital tibial and fibular shortenings but also predisposes to congenital anteromedial bowing of the tibia.

Missing Midline Metatarsals Conform to Plantar Arterial Arch Dysgenesis

Midline metatarsal ray deficiencies, which occur in approximately half of congenital short limbs with fibular deficiency, provide the most distal and compelling manifestation of a fluid spectrum of human lower-extremity congenital long bone reductions; this spectrum syndromically affects the long bone triad of the proximal femur, fibula, and midline metatarsals. The bony deficiencies correspond to sites of rapid embryonic arterial transitioning. Long bones first begin to ossify because of vascular invasions of their respective mesenchymal/cartilage anlagen, proceeding in a proximal-to-distal sequence along the forming embryonic limb. A single-axis artery forms initially in the embryonic lower limb by means of vasculogenesis. Additional arteries evolve in overlapping transitional waves, in proximity to the various anlagen, during the sixth and seventh weeks after fertilization. An adult pattern of vessels presents by the eighth week. Arterial alterations, in the form of retained primitive embryonic vessels and/or reduced absent adult vessels, have been observed clinically at the aforementioned locations where skeletal reductions occur. Persistence of primitive vessels in association with the triad of long bone reductions allows a heuristic estimation of the time, place, and nature of such coupled vascular and bony dysgeneses. Arterial dysgenesis is postulated to have occurred when the developing arterial and skeletal structures were concurrently vulnerable to teratogenic insults because of embryonic arterial instability, a risk factor during arterial transition. It is herein hypothesized that flawed arterial transitions subject the prefigured long bone cartilage models of the rapidly growing limb to the risk of teratogenesis at one or more of the then most rapidly growing sites. Midline metatarsal deficiency forms the keystone of this developmental concept of an error of limb development, which occurs as a consequence of failed completion of the medial portion of the plantar arch. Therefore, the historical nomenclature of congenital long bone deficiencies will benefit from modification from a current reliance on empirical physical taxonomies to a developmental foundation.

Congenital fibular dystrophisms conform to embryonic arterial dysgenesis

The congenital short limb (CSL) with fibular deficiency has traditionally been graded by plain radiography. The most popular orthopedic classification sorts the fibular dysmorphologies into three radiographic groupings: IA (thinned), IB (proximally truncated), or II (absent). In contrast, the soft tissues have been relatively neglected. Since bone formation of the fibula progresses from the anlage, a scaffolding cartilage mold intermediate, cartilage transformation to bone is dependent upon timely embryonic arterial invasion. Absences of the requisite arteries predicate specific skeletal dysmorphologies. The usual arterial supply of the fibula is comprised primarily of the anterior tibialis artery (ATA), which uniquely supplies the proximal portion of the fibula, and also joins the peroneal artery (PA) in supplying the mid to distal fibular shaft. Combinations of the two nutrient arteries allow four potential variations of fibular vascular supply, among which the ATA and PA conjoin to supply the normal fibula and variably supply the three dysmorphic fibular models. The IA and IB deformities conform, respectively, to the absences of the PA and the ATA. Combined ATA and PA absences present in the radiographically "absent" fibula. Thus, each of the four fibular (dys)morphologies conforms to a specific embryonic pattern of arterial development. The term "dystrophism" most accurately characterizes such malformed long bones.

Postaxial limb hypoplasia (PALH): the classification, clinical features, and related developmental biology

Postaxial limb hypoplasia (PALH) is a group of nonhereditary diseases with congenital lower limb deficiency affecting the fibular ray, including fibular hemimelia, proximal femoral focal deficiency, and tarsal coalition. The etiology and the developmental biology of the anomaly are still not fully understood. Here, we review the previous classification systems, present the clinical features, and discuss the developmental biology of PALH.

The Nature of Foot Ray Deficiency in Congenital Fibular Deficiency

BACKGROUND

Absent lateral osseous structures in congenital fibular deficiency, including the distal femur and fibula, have led some authors to refer to the nature of foot ray deficiency as "lateral" as well. Others have suggested that the ray deficiency is in the central portion of the midfoot and forefoot.We sought to determine whether cuboid preservation and/or cuneiform deficiency in the feet of patients with congenital fibular deficiency implied that the ray deficiency is central rather than lateral in patients with congenital fibular deficiency.

METHODS

We identified all patients with a clinical morphologic diagnosis of congenital fibular deficiency at our institution over a 15-year period. We reviewed the records and radiographs of patients who had radiographs of the feet to allow determination of the number of metatarsals, the presence or absence of a cuboid or calcaneocuboid fusion, the number of cuneiforms present (if possible), and any other osseous abnormalities of the foot. We excluded patients with 5-rayed feet, those who had not had radiographs of the feet, or whose radiographs were not adequate to allow accurate assessment of these radiographic features. We defined the characteristic "lateral (fifth) ray present" if there was a well-developed cuboid or calcaneocuboid coalition with which the lateral-most preserved metatarsal articulated.

RESULTS

Twenty-six patients with 28 affected feet met radiographic criteria for inclusion in the study. All affected feet had a well-developed cuboid or calcaneocuboid coalition. The lateral-most ray of 25 patients with 26 affected feet articulated with the cuboid or calcaneocuboid coalition. One patient with bilateral fibular deficiency had bilateral partially deficient cuboids, and the lateral-most metatarsal articulated with the medial remnant of the deformed cuboids. Twenty-one of 28 feet with visible cuneiforms had 2 or 1 cuneiform.

CONCLUSIONS

Although the embryology and pathogenesis of congenital fibular deficiency remain unknown, based on the radiographic features of the feet in this study, congenital fibular deficiency should not be viewed as a global "lateral lower-limb deficiency" nor the foot ray deficiency as "lateral."

LEVEL OF EVIDENCE

Level IV-prognostic study.

Clinical Results and Complications of Lower Limb Lengthening for Fibular Hemimelia: A Report of Eight Cases

Fibular hemimelia is a rare but the most common congenital long bone deficiency, encompassing a broad range of anomalies from isolated fibular hypoplasia up to substantial femoral and tibial shortening with ankle deformity and foot deficiency. Most cases of fibular hemimelia manifest clinically significant leg length discrepancy (LLD) with time that requires adequate correction by bone lengthening for stable walking. Bone lengthening procedures, especially those for pathological bones, are sometimes associated with severe complications, such as delayed consolidation, fractures, and deformities of the lengthened bones, leading to prolonged healing time and residual LLD at skeletal maturity. The purpose of this study was to review our clinical results of lower limb lengthening for fibular hemimelia.This study included 8 Japanese patients who diagnosed with fibular hemimelia from physical and radiological findings characteristic of fibular hemimelia and underwent single or staged femoral and/or tibial lengthening during growth or after skeletal maturity. LLD, state of the lengthened callus, and bone alignment were evaluated with full-length radiographs of the lower limb. Previous interventions, associated congenital anomalies, regenerate fractures were recorded with reference to medical charts and confirmed on appropriate radiographs. Successful lengthening was defined as the healing index <50 days/cm without regenerate fractures.A significant difference was observed in age at surgery between successful and unsuccessful lengthening. The incidence of regenerate fractures was significantly correlated with callus maturity before frame removal. LLD was corrected within 11 mm, whereas mechanical axis deviated laterally.Particular attention should be paid to the status of callus maturation and the mechanical axis deviation during the treatment period in fibular hemimelia.

Massage therapy effects in a long-term prosthetic user with fibular hemimelia

BACKGROUND

Individuals with lower limb amputation (LLA) commonly experience low back pain (LBP). Although massage effects on LBP are well-documented, research regarding massage for individuals with LLA is scarce.

OBJECTIVES

This study evaluated the effectiveness of massage therapy to promote activity level, decrease LBP, and improve health-related quality of life (HRQOL) in a long-term prosthetic user.

METHODS

The 50-day study consisted of two baseline sessions, seven treatment sessions that included a 50-min massage applied to major gait muscles, and two follow-up sessions. Pedometer-measured ambulatory activity level, visual analog scale-measured pain level, and RAND-36 Health Survey 1.0-determined HRQOL were assessed.

RESULTS

Pain level decreased, HRQOL increased, and no change occurred in ambulatory activity level.

CONCLUSION

For the participant, therapeutic massage intervention lead to successful LBP symptom management.

Prevention of recurrence of tibia and ankle deformities after bone lengthening in children with type II fibular hemimelia

PURPOSE

This study aimed to evaluate development of the tibia after Ilizarov lengthening and deformity correction depending on whether or not the simultaneous resection of fibular anlage was performed in children with fibular aplasia type II, who did not undergo early surgery.

METHODS

The study analyses results of reconstructive treatment in 38 children at the age of over four years. Two groups of children are compared: bifocal tibial lengthening with the Ilizarov device (group I) and bifocal lengthening associated with resection of the fibular anlage (group II). The results were estimated at 12 months and in the long-term exceeding three years.

RESULTS

Radiological data of measurement of the anatomical lateral distal tibial angle (aLDTA) show surgical correction of deformities achieved in both groups. During the further limb growth a tendency to normalisation of the aLDTA was observed only in the group II. Quick relapse of the angular deformities of the tibial shaft in the first group occurred mainly during further growth of the limb regardless of complete correction at the time of treatment. On the other hand, there were no recurrences of diaphyseal deformities in the group II.

CONCLUSIONS

In children with congenital fibular deficiency of type II at the age of four years, the bone lengthening and deformity correction should be associated with fibular anlage resection. That approach improves conditions for distal tibia development and prevents or decreases significantly the recurrence of deformities of the tibia and ankle joint in long-term follow-up.

Internal lengthening device for congenital femoral deficiency and fibular hemimelia

BACKGROUND

Patients with congenital limb shortening can present with joint instability, soft tissue contractures, and significant leg length discrepancy. Classically, lengthening is done with external fixation, which can result in scarring, pin site infection, loss of motion, and pain. We therefore developed an alternative to this approach, a new, controllable, internal lengthening device for patients with congenital limb shortening.

QUESTIONS/PURPOSES

We evaluated this device in terms of (1) healing index, (2) complications, (3) accuracy of the device's external controller, and (4) adjacent-joint ROM.

METHODS

Between January 2012 and May 2013, we treated 66 patients for congenital limb shortening, of whom 21 were treated using this device. During this period, general indications for using the device were patients with leg length discrepancies of 2 cm or more, with intramedullary canals able to withstand rods of at least 12.5-mm diameter and 230-mm length, without active infection in the affected bone, able to comply with the need for frequent lengthening, and without metal allergies or an implanted pacemaker. We included only those patients who had completed their course of treatment and were currently fully weightbearing, leaving 18 patients (21 bone segments) available for followup at a minimum of 6 months after limb lengthening (mean, 14 months; range, 6-22 months). Mean age was 19 years (range, 9-49 years). Sixteen femurs and five tibias were lengthened a mean of 4.4 cm (range, 2.1-6.5 cm). Mean distraction index was 1.0 mm/day (range, 0.5-1.8 mm/day). Healing index, complications, device accuracy, and ROM were recorded. To date, 10 of the 21 devices have been removed. This was typically done 12-24 months after insertion when the bone was solidly healed on all four cortices.

RESULTS

Mean healing index was 0.91 months/cm (range, 0.2-2.0 months/cm). There were seven complications requiring an additional unplanned surgery, including one hip flexion contracture, three femurs with delayed healing, one tibia with delayed healing, one hip subluxation/dislocation, and one knee subluxation. The external controller was accurate as programmed and actual lengthening amounts were consistent. ROMs of the hip, knee, and ankle were essentially maintained.

CONCLUSIONS

This device is completely internal, allowing for satisfactory joint motion during treatment in most patients. Lengthening was achieved in an accurate, controlled manner, and all patients reached their goal length. Complications remain a concern, as is the case with all approaches to this complex patient population. Both future comparative studies and longer-term followup are needed.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Internal derangement of the knee in fibular hemimelia: radiographic and MRI findings

BACKGROUND

Fibular hemimelia is a rare bone dysplasia with partial or complete absence of the fibula. There are many associated lower limb deformities.

METHODS

We describe the commonly associated bone and soft tissue abnormalities in the knee joint in a case series of six knees in five patients with fibular hemimelia who underwent both radiographic and MR imaging.

RESULTS

In all knees, there was an elongated conjoint tendon of the lateral collateral ligament and biceps femoris. In five out of six knees, there was trochlear dysplasia. In four out of six, there was complete absence of the anterior cruciate ligament. In four out of six, there was an abnormal lateral meniscus (three were hypoplastic and one absent).

CONCLUSION

These associations in fibular hemimelia, although unpredictable, have relevance in the guidance of further orthopaedic management in this complex condition.

Congenital fibular deficiency

Congenital fibular deficiency (CFD) is characterized by a wide spectrum of manifestations ranging from mild limb length inequality (LLI) to severe shortening, with foot and ankle deformities and associated anomalies. The etiology of CFD remains unclear. Treatment goals are to achieve normal weight bearing, a functional plantigrade foot, and equal limb length. The recent Birch classification system has been proposed to provide a treatment guide: the functionality of the foot, LLI, and associated anomalies should be taken into account for decision-making. Treatment options include orthosis or epiphysiodesis, Syme or Boyd amputation and prosthetic rehabilitation, limb lengthening procedures, and foot and ankle reconstruction. The outcome of amputation for severe forms of CFD has shown favorable results and fewer complications compared with those of limb lengthening. Nevertheless, advances in the limb lengthening techniques may change our approach to treating patients with CFD and might extend the indications for reconstructive procedures to the treatment of severe LLI and foot deformities.