Outcomes of Limb Lengthening With Computer-assisted Hexapod External Fixators in the Treatment of Fibular Hemimelia.

BACKGROUND: Fibular hemimelia (FH) represents the most common deficiency of the long bones and is associated with multiple deformities. Reconstructive treatment with external fixators in FH restores normal lower extremity alignment and length with plantigrade feet for a balanced and effective gait. The aim of this study is to evaluate the outcomes of lower limb lengthening and simultaneous tri-plane deformity correction with a computer-assisted hexagonal external fixator in children with FH. METHODS: A retrospective review was performed for FH cases treated with a computer-assisted hexagonal external fixator in a tertiary referral center. Leg length discrepancy (LLD), interphyseal angles, tibiocalcaneal distances, healing index (HI), and callus shapes were analyzed for radiologic evaluation, and the Pediatric Quality of Life Inventory (PedsQL) was used for functional assessment. Limbs with HI <50 days/cm, PedsQL >75, and without regenerate fractures were considered successful lengthenings. RESULTS: Twenty-four limbs of 23 patients were included. The limbs were lengthened for a mean of 7.24 cm (range, 4.7 to 15.6). The initial LLD of 5.6 cm (range, 0.5 to 19 cm) increased to 1.7 cm (range, 0.1 to 6 cm), and the mean interphyseal angle was 12.7 degree (range, 1.5 to 54.2 degree), tibiocalcaneal distance was 0.85 cm (range, 0.1 to 1.7) at final follow-up. The most common regenerated bone morphology was cylindrical, as seen in 11 limbs (45.8%). The average PedsQL score was 83.5 (range, 69.5 to 96.7). Sixteen limbs (66.7%) had successful lengthening at their first, and 4 limbs (80%) had successful lengthening at their second surgeries. Seven limbs had complications requiring surgical intervention (29.1%), with 3 (12.5%) regenerate fractures after external fixators removal. CONCLUSIONS: Limb reconstruction with computer-assisted hexapod fixators is a successful and reliable option for the treatment of LLD in FH, and patients demonstrate good functional outcomes. Surgeons should be aware of potential complications and should utilize prophylactic measures when necessary. LEVELS OF EVIDENCE: Level III, retrospective comparative study.

Anesthetic management in an infant with tetra-amelia syndrome with congenital maxillomandibular fusion: A case report.

A 10-month-old girl who had tetra-amelia syndrome and congenital maxillomandibular fusion (syngnathia) was scheduled for the surgical fusion separation. Anesthetic management for this case was considerably challenging. Standard monitoring was still applied to the patient's extremities. IV access was suspected to be difficult but firmly needed before intubation to provide resuscitation during an emergency. Connecting anesthetic circuit with nasopharyngeal airway was the preferred technique due to its benefits such as maintaining spontaneous ventilation, providing inhaled anesthetic, as well as monitoring oxygenation and ventilation. Importantly, the cornerstones for handling such complicated cases are multidisciplinary approach and teamwork.

Roberts syndrome in an Indian patient with humeroradial synostosis, congenital elbow contractures and a novel homozygous splice variant in ESCO2.

Roberts syndrome (also known as Roberts-SC phocomelia syndrome) is an autosomal recessive developmental disorder, characterized by pre- and postnatal growth retardation, limb malformations including bilateral symmetric tetraphocomelia or mesomelia, and craniofacial dysmorphism. Biallelic loss-of-function variants in ESCO2, which codes for establishment of sister chromatid cohesion N-acetyltransferase 2, cause Roberts syndrome. Phenotypic spectrum among patients is broad, challenging clinical diagnosis in mildly affected individuals. Here we report a 3-year-old boy with a mild phenotype of Roberts syndrome with bilateral elbow contractures, humeroradial synostosis, mild lower limb disparity, and facial dysmorphism. Trio whole-exome sequencing identified the novel biallelic splice variant c.1673+1G>A in ESCO2 in the patient. Aberrant ESCO2 pre-mRNA splicing, reduced relative ESCO2 mRNA amount, and characteristic cytogenetic defects, such as premature centromere separation, heterochromatin repulsion, and chromosome breaks, in patient cells strongly supported pathogenicity of the ESCO2 variant affecting one of the highly conserved guanine-thymine dinucleotide of the donor splice site. Our case highlights the difficulty in establishing a clinical diagnosis in individuals with minor clinical features of Roberts syndrome and normal intellectual and social development. However, next-generation sequencing tools allow for molecular diagnosis in cases presenting with mild developmental defects.

Lengthening With Monolateral External Fixation Versus Magnetically Motorized Intramedullary Nail in Congenital Femoral Deficiency.

BACKGROUND: Limb lengthening for congenital femoral deficiency (CFD) with or without fibular hemimelia can be performed with both external and internal devices. The purpose of this study is to compare clinical outcomes of femoral lengthening utilizing monolateral external fixation versus a magnetically motorized intramedullary nail in patients with CFD with or without fibular hemimelia. METHODS: This retrospective review included 62 patients with femoral lengthening, 32 patients had monolateral external fixation (group A), 30 patients had internal lengthening nail (group B). Mean age in years was 9.4±3.8 and 15.4±4.9 for groups A and B, respectively. Mean follow-up in years was 4.47±2.7 and 1.86±0.7 years for groups A and B, respectively. RESULTS: Mean lengthening achieved was 5.6±1.7 and 4.8±1.4 cm for group A and group B, respectively (P=0.052). Mean distraction index was 0.7±0.2 mm/d for group A and 0.7±0.2 mm/d for the group B (P=0.99). Mean consolidation index for group A was 29.3±12.7 and 34.8±11.2 d/cm for group B (P=0.08). Mean arc of motion before surgery and at final follow-up were similar between groups (P=0.35). Group A had significantly less range of motion at the end of distraction (P=0.0007) and at consolidation (P<0.0001). Both groups had similar rates of obstacles and complications. A significant difference between groups was found in the total problems (P<0.001) specifically with pin site/superficial infection (P<0.0001). CONCLUSIONS: The intramedullary nail had superior range of motion during the lengthening phase and at consolidation and an overall lower problem complication rate, while maintaining similar distraction and healing indices to monolateral external fixation. Internal lengthening nails represent a significant advance in technology for CFD lengthening. LEVEL OF EVIDENCE: Level IV-therapeutic.

Use of Paley Classification and SUPERankle Procedure in the Management of Fibular Hemimelia.

BACKGROUND: Fibular hemimelia is the most common deficiency involving the long bones. Paley classification is based on the ankle joint morphology, identifies the basic pathology, and helps in planning the surgical management. Reconstruction surgery encompasses foot deformity correction and limb length equalization. The SUPERankle procedure is a combination of bone and soft tissue procedures that stabilizes the foot and addresses all deformities. METHODS: We retrospectively reviewed 29 consecutive patients (29 limb segments), surgically treated between December 2000 and December 2014. Among the 29 patients, 27 were treated with reconstructive procedures. Type 1 (8 patients) cases were treated with only limb lengthening, and correction of tibial deformities. Type 2 (7 patients) cases were treated by distal tibial medial hemiepiphysiodesis or supramalleolar varus osteotomy. In type 3 (10 patients) cases, the foot deformity was corrected using the SUPERankle procedure. Type 4 (2 patients) cases were treated with supramalleolar osteotomy along with posteromedial release and lateral column shortening. In a second stage, limb lengthening was performed, using the Ilizarov technique. In the remaining 2 patients (type 3A and type 3C), amputation was performed using Syme technique as a first choice of treatment. RESULTS: The results were evaluated using Association for the Study and Application of Methods of Ilizarov scoring. Excellent results were obtained in 15 of 27 (55%) patients. Six (22%) patients had good results, 4 (14.8%) had fair results, and 2 (7%) had poor results. Mean limb length discrepancy at initial presentation was 3.55 cm (range: 2 to 5.5 cm) which significantly improved to 1.01 cm (range: 0 to 3 cm) after treatment (P=0.015). CONCLUSIONS: Our results and a review of the literature clearly suggest that limb reconstruction according to Paley classification, is an excellent option in the management of fibular hemimelia. Our 2-staged procedure (SUPERankle procedure followed by limb lengthening) helps in reducing the complications of limb lengthening and incidence of ankle stiffness. Performing the first surgery at an earlier age (below 5 y) plays a significant role in preventing recurrent foot deformities. LEVEL OF EVIDENCE: Level IV.

Complex Anatomic Abnormalities of the Lower Leg Muscles and Tendons Associated With Phocomelia: A Case Report.

Musculoskeletal anatomy is widely known to have components that stray from the norm in the form of variant muscle and tendon presence, absence, origin, insertion, and bifurcation. Although these variant muscles and tendons might be deemed incidental and insignificant findings by most, they can be important contributors to pathologic physiology or, more importantly, an option for effective treatment. In the present case report, we describe a patient with phocomelia and Müllerian abnormalities secondary to in utero thalidomide exposure. The patient had experienced recurrent bilateral foot pain accompanied by numbness, stiffness, swelling, and longstanding pes planus. These symptoms persisted despite conservative treatment with orthotics, steroids, and nonsteroidal anti-inflammatory drugs. Radiographic imaging showed dysmorphic and degenerative changes of the ankle and foot joints. Further investigation with magnetic resonance imaging revealed complex anatomic abnormalities, including the absence of the posterior tibialis and peroneus brevis, lateralization of the peroneus longus, and the presence of a variant anterior compartment muscle. The variant structure was likely a previously described anterior compartment variant, anterior fibulocalcaneus, and might have been a source of the recurrent pain. Also, the absence of the posterior tibialis might have caused the pes planus in the present patient, considering that posterior tibialis tendon dysfunction is the most common cause of acquired pes planus. Although thalidomide infrequently affects the lower extremities, its effects on growth and development were likely the cause of this rare array of anatomic abnormalities and resulting ankle and foot pathologic features.

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.

A child with split-hand/foot associated with tibial hemimelia (SHFLD syndrome) and thrombocytopenia maps to chromosome region 17p13.3.

We describe a-2-year-old boy who presented with a neonatal history of thrombocytopenia associated with a constellation of limb malformations mimicking split hand/foot malformation with long bone deficiency (SHFLD) syndrome. Limb malformations consisted of unilateral monodactyly with radial aplasia, unilateral split foot and bilateral club foot. Tibial aplasia of one limb and tibial hypoplasia of the other limb were notable. Partial agenesis of the sacrum was additional skeletal malformation. Craniofacial features included dense thick scalp hair, narrow frontal area, thick eye-brows, deep-set eyes, depressed nasal bridge, and small overhanging nasal tip, full-cheeks, and large ears. Array-CGH showed duplication of the short arm of chromosome 17p13.3 in the boy and his father, respectively. The father was free from any skeletal abnormalities, though he shares similar craniofacial dysmorphic features like his son. In addition, a paternal sib (uncle of the proband) manifested a phenotype similar to that of the proband. To the best of our knowledge the overall phenotypic and genotypic characterizations were consistent but not completely compatible with the traditional type of TAR syndrome or with SHFLD syndrome. We report on what might be a novel variant of SHFLD associated with transient thrombocytopenia, dysmorphic facial features, and a constellation of bone malformations.

A case of severe proximal focal femoral deficiency with overlapping phenotypes of Al-Awadi-Raas-Rothschild syndrome and Fuhrmann syndrome.

Proximal focal femoral deficiency (PFFD) is a heterogeneous disorder characterized by various degrees of femoral deficiencies and associated anomalies of the pelvis and lower limbs. The etiology of the disease has not been determined. We report on a 3-year-old boy with severe PFFD, who showed almost completely absent femora and fibulae, malformed pelvis and ectrodactyly of the left foot. These features were partially overlapped with those of Al-Awadi-Raas-Rothschild syndrome or Fuhrmann syndrome, both of which are caused by WNT7A mutations. Molecular analysis of our case, however, demonstrated no disease-causing mutations in the WNT7A gene.

A fetus with hemifacial microsomia and sirenomelia. The same mesodermal defect spectrum?

Sirenomelia is the most severe malformation complex affecting the human caudal pole, although its etiology is unclear, a primary defect of blastogenesis has been proposed. Studies consider sirenomelia as the most severe form of caudal dysgenesis, VACTERL association, or axial mesodermal dysplasia, although others still support the idea of a different pathologic entity. We report the prenatal, clinical, and pathologic features of a fetus with cleft lip and palate, microtia, cardiac, renal and intestinal malformations, radial aplasia, and sirenomelia. Karyotype, chromosomal breakage studies, and SHH sequence analysis were normal. The occurrence of cephalic, midline-paramedial, and caudal malformations in the same patient imply the diagnosis of hemifacial microsomia and sirenomelia. These entities are part of the same mesodermal malformation spectrum and the clinical presentation depends on environmental and genetic interactions in embrionic development. Future clinical and genome wide studies will help to better delineate this spectrum.

Case report: vertebral body tethering for idiopathic scoliosis in a patient with bilateral phocomelia.

PURPOSE: The purpose of this study is to present a case report of a patient with bilateral upper extremity phocomelia with progressive scoliosis, who underwent vertebral body tethering (VBT). METHODS: This is a case report on the use of VBT in a patient with scoliosis and bilateral congenital phocomelia, with 5 year follow-up. RESULTS: A male patient with bilateral phocomelia had early onset scoliosis that progressed to 45° at age 10. Surgical options were discussed, including traditional VBT, posterior spinal fusion, growing rods, magnetically controlled growing rods, and vertical expandible prosthetic titanium ribs. These options would limit the flexibility of the spine. Given these pitfalls, VBT was chosen, as it would address the scoliosis while maintaining trunk flexibility. Preoperatively, he had 45° right main thoracic curve, bending to 22°; he was Risser 0 with open triradiate cartilage. He underwent T6-T11 thoracoscopic VBT, with postoperative correction to 37°. Postoperatively, the patient was able to continue to use his lower extremities for writing, feeding, and personal grooming. He had no postoperative complications. At 3 years, his curve was 21°, and at 5 years was 19°. CONCLUSION: This case describes a novel technique for treating scoliosis in patients with bilateral phocomelia. Other forms of scoliosis surgical treatment limit motion of the spine. Due to this, we present VBT as an option for this unique set of patients for correcting scoliosis, while also preserving trunk flexibility for its role in feeding and self-care.

Simultaneous femoral and tibial lengthening for severe limb length discrepancy in fibular hemimelia.

BACKGROUND: Fibular Hemimelia (FH) is the most common longitudinal limb deficiency. Significant limb length discrepancy (LLD) will necessitate long treatment times and multiple settings to compensate for LLD when associated with femoral shortening. This study evaluates the outcome of simultaneous femoral and tibial lengthening using the Ilizarov frame. METHODS: This retrospective study included the cases of 12 children with severe limb length discrepancy caused by combined FH and ipsilateral femoral shortening from May 2015 to August 2022. The total LLD ranged from 7 to 14.5 cm. All patients underwent single-session femoral and tibial lengthening using the Ilizarov ring external fixator technique. Additional procedures were performed in the same setting, including Achilles tendon lengthening, fibular anlage excision, peroneal tendons lengthening, and iliotibial band release. Follow-up ranged from 2 to 4 years. RESULTS: The planned limb lengthening was achieved in ten cases (83%). No cases of joint subluxation or dislocation were encountered. No neurovascular injury has occurred during the treatment course. In all cases, the bone healing index was better on the femoral side than on the tibia. Poor regeneration and deformity of the tibia occurred in two cases (16.6%). CONCLUSION: Simultaneous femoral and tibial lengthening using the Ilizarov fixator is a relatively safe procedure with the result of correction of total LLD in one session in a shorter time and less morbidity.

[Sirenomelia--a rare cause of an oligoanhydramnion in the second trimester--a case report]. / Sirenomelie--eine seltene Ursache für ein Oligo-hydramnion im zweiten Trimester--Ein Fallbericht.

Sirenomelia is a rare, but complex and lethal malformation. It is caused by a primary defect of the caudal axial skeleton and damage to the primary streak, which appears due to a vascular steal phenomenon. Sirenomelia appears sporadic with an incidence of 1-64,000 births. A risk for sirenomelia can be also found in patients with poorly controlled diabetes mellitus and in monocygotic twins. Leading ultrasound findings are fusioned lower extremities, bilateral renal agenesis, single umbilical artery and a distinct oligohydramnios. 3D ultrasound and color Doppler sonography can additionally be used for diagnostic, as well as amnioninfusion. There are 3 forms of sirenomelia, depending on missing or presence of the feet it is distinguished as sympus apus, monopus or dipus. We are presenting a case of sirenomelia with sympus dipus, which was transferred for further diagnostic of severe oligohydramnios in 21 weeks of gestation by the gynecologist.

Fibular hemimelia.

Fibular hemimelia is defined as a partial or complete absence of the fibula. Alongside fibular deformities, there is a wide spectrum of anomalies, foot deformities, and absent rays. A literature review showed only a handful of cases of prenatal diagnosis of fibular hemimelia. It is a rare disorder that might be isolated or associated with visceral anomalies.

Possible mistakes in prediction of bone maturation in fibular hemimelia by Moseley chart.

The purpose of this study was to establish a nomogram in order to predict limb length discrepancies in children with unilateral fibular hemimelia more accurately. In 31 children with unilateral fibular hemimelia the femoral-tibial length and skeletal age were determined an average of seven times per case by sequential radiographs during growth. From the data, a skeletal age nomogram was developed which shows a steeply declining mean skeletal age pattern in unilateral fibular hemimelia (the slope in girls was -0.59 and in boys -0.64). This nomogram crosses the normal mean skeletal age line of the Moseley straight-line graph at 10.5 years in girls and at 12 years in boys, and continues to decline until maturity. The results demonstrate an abnormal skeletal maturation process in patients with unilateral fibular hemimelia. The consistently declining steep skeletal age nomogram in unilateral fibular hemimelia makes prediction of skeletal maturity and limb length discrepancy inaccurate by the standard predictive methods particularly when using early skeletal ages. The skeletal age nomogram from our data determines skeletal maturation in children with unilateral fibular hemimelia more accurately, and allows a correct prediction of limb length discrepancy.

Recurrence of axial malalignment after surgical correction in congenital femoral deficiency and fibular hemimelia.

PURPOSE: Recurrent genu valgum deformity complicates treatment of congenital femoral deficiencies (CFD) and fibular hemimelia (FH). We analysed factors influencing recurrence. METHODS: Patients who underwent limb lengthening or deformity correction for CFD and/or FH were reviewed. Radiographs after surgery and after a minimum of a further six months were analysed. Change in parameters of mechanical axis deviation per month (∆ MAD/month) and of angle per month were calculated. These parameters were tested against cofactors patient age, baseline MAD, type of CFD and FH, severity of ball-and-socket joints, ankle-joint stiffness, absence of cruciate ligaments and resection of the fibular anlage. RESULTS: Recurrent valgus deformity was found in 23 of the 42 limbs included with a mean change of MAD of 23.4 mm (5-60 mm). There was no significant difference between patients with ∆ MAD/month <0.5 mm versus >1 mm regarding MAD in the first radiograph and patient age. CFD cases Pappas types VII and VIII showed a ∆ MAD/month of 1.6 mm, whereas milder cases of Pappas IX showed a ∆ MAD/month of 0.8. Mild FH (type Ia) showed a mean ∆ MAD/month of 0.39 mm, whereas mean ∆ MAD/month for FH type Ib/II was 0.72 mm. In FH type II cases, mean ∆ MAD/month was 0.79 mm after resection of the fibular anlage compared with 1.98 mm in those without resection. CONCLUSIONS: Recurrence in FH and CFD was not dependent on patient age but partly on FH and CFD type. Limbs with more severe ball-and-socket knee joints showed more recurrence. Overcorrection depending deformity type should be performed.

Sirenomelia and VACTERL association in the offspring of a woman with diabetes.

Sirenomelia and VACTERL association are defects of blastogenesis of unknown cause. Although they appear clinically distinct, some epidemiological and experimental studies suggest a common pathogenetic mechanism. We report on the reproductive history of a 28-year-old obese, diabetic mother who had three pregnancies. The first resulted in the birth of a sirenomelic child, the second in a miscarriage, while the third was terminated for fetal malformations, diagnosed post-mortem as VACTERL association. This observation supports the relationship between sirenomelia and VACTERL, which probably represent the two ends of the same phenotypic spectrum. Their occurrence in the same sibship also indicates a possible common cause. The coexistence with maternal diabetes seems more than a chance occurrence and the constellation of malformations observed in the present family may be explained as the pleiotropic effect of the same teratogenic agent interacting with genetic predisposition to diabetes and/or obesity.

A novel homozygous Arg222Trp missense mutation in WNT7A in two sisters with severe Al-Awadi/Raas-Rothschild/Schinzel phocomelia syndrome.

Al-Awadi/Raas-Rothschild/Schinzel phocomelia (AARRS) syndrome, a rare autosomal recessive disorder, comprises malformations of upper and lower limbs with severely hypoplastic pelvis and abnormal genitalia. Mutations in WNT7A have been reported as cause of the syndrome. We report on two sisters in a Thai family with short and malformed long bones, absent fibulae, flexion contracture of digits, and a/hypoplastic nails. Fusion between severely malformed femora and slender tibiae has never been reported in patients with WNT7A mutations. Lower limbs were more severely malformed than the upper ones and the pelvis was also severely affected. Multiple fusions of long bones and of the femoral heads to the acetabula were evident. A novel homozygous missense mutation in coding exon 4 of the WNT7A was detected in both affected daughters (c.664C > T) leading to an amino acid exchange from arginine to tryptophan (p.Arg222Trp; R222W). The phenotype is likely to result from an abnormality of all three signaling centers in the developing limb resulting in ventralization with a loss of dorsal structures (aplasia/hypoplasia of nails) a loss of anterior-posterior identity (single distal bones in lower limb without polarity) and an outgrowth defect resulting in distal truncations.

Genetic and pathologic aspects of retinoic acid-induced limb malformations in the mouse.

Because all-trans retinoic acid (atRA) is teratogenic in all species tested and many of the specific defects induced are common across the phylogenetic spectrum, it would be logical to predict that murine strain differences in teratology to this agent are minimal. However, for specific defects, strain susceptibilities are vastly different. Studies with atRA have shown stark differences between C57BL/6 and SWV mouse strains in susceptibility to postaxial forelimb ectrodactyly and ectopic hindlimb formation, with the C57 strain being more susceptible for both defects. Various approaches were used to determine why these strains differ in susceptibility, but the mechanisms remain unknown. Hindlimb duplications were hypothesized to be caused by the formation of ectopic posterior body axes. For forelimb ectrodactyly, a locus on chromosome 11, Rafar, has linkage to the strain difference, and mRNA localization has shown that specific genes (Fgf8, Dlx3, Bmp4, and Sp8) in the postaxial preAER (prior to formation of the apical ectodermal ridge) of the developing limb bud (the site of the defect) were downregulated hours after atRA administration more in the susceptible C57 than in the SWV strain. Because both atRA and divalent cadmium induce postaxial forelimb ectrodactyly (right-sided predominance) at a high rate in C57BL/6 and low in the SWV strain, there is debate as to whether they share a common mechanism. These teratogens cause a greater-than-additive level of forelimb ectrodactyly when coadministered at low doses, but cadmium does not induce ectopic hindlimb formation. The hypothesis is that these agents have separate molecular pathologic pathways that converge to perturb a common anatomic structure.