Bone allografting: an original method for biological osteosynthesis and bone reinforcement in children with osteogenesis imperfecta.

PURPOSE: Osteogenesis imperfecta (OI) is a genetic disorder responsible for various symptoms including deformities and frequent fractures. Bone allografting is poorly documented in this condition. The objective of this study was to describe our experience and assessments in a consecutive series of OI patients. METHODS: Thirty-nine lower limb allograft procedures (28 femurs, 11 tibias) were performed in 26OI patients (mean age, 12.9 years). They were classified as type III of Sillence (17), type IV (6), and 3 recessive forms. The indications for surgery were correction of deformity (19), fracture (16), and non-union (4). In all cases, bone allografting was added to reinforce areas of fragility and in 28 cases for osteosynthesis to lock the rotations at the osteotomy site and to avoid screwed metallic plate. The duration of bone consolidation and allograft fusion was assessed. Complications and Gillette functional score were reported. RESULTS: The mean follow-up was 6.7years (range, 2 to 10 years). On average, bone consolidation was achieved after 3.3 months and graft fusion after 7.7 months. No bone allograft-related complications were observed and there was any secondary displacement. The Gillette functional score was improved in 23 patients and stable in three cases. Complications were reported in two cases: one partial allograft resorption and one delayed consolidation of a non-union. One refracture was observed but after a significant trauma in a child who had regained significant physical activity. CONCLUSIONS: Bone allografting in children with OI is a reliable method of biological fixation, allowing efficient fusion and contributing to increased bone capital and functional outcome.

Tibial Sliding Elastic Nailing Technique in Moderate-to-Severe Osteogenesis Imperfecta: Long-term Outcomes.

BACKGROUND: Osteosynthesis of leg fractures and deformities in children with osteogenesis imperfecta should align the skeleton and overcome its fragility during growth with a telescopic effect. A high rate of mechanical complications is associated with various surgical techniques described in the literature. PURPOSE: The objective of this work was to assess the long-term clinical and radiologic outcomes of tibial sliding elastic nailing technique. METHODS: A total of 22 children with an average age of 4.7 years were operated using the technique between 2004 and 2018 unilaterally (6) or bilaterally (16), that is, 38 operations. They were listed according to the Sillence classification into type I (3), III (17), or V (2). The nails were introduced percutaneously at the distal tibial epiphysis through the medial malleolus, and in the prespinal area for the proximal tibial epiphysis. The stainless-steel rods diameter was 1.5 to 2.5 mm, adapted to the size and weight of the patient. Realignment osteotomies were performed if necessary. Radiographic data including the correction of the deformation in the frontal and sagittal planes, as well as the width at mid-shaft of the tibia in the frontal and sagittal planes, were reviewed. Gillette Functional Score, assessment of pain, mechanical and infectious complications were collected. RESULTS: The average follow-up was 8.6 years. In the frontal plane, preoperative average varus was 8 degrees (maximum, 40 degrees), 5 degrees (maximum, 13 degrees) postoperatively, and 6 degrees (maximum, 12 degrees) at last follow-up. Preoperative valgus was 11 degrees (maximum, 22 degrees), 9 degrees (maximum, 15 degrees) postoperatively, and 9 degrees (maximum, 14 degrees) at the last follow-up. In the sagittal plane, the mean sagittal bowling of the tibia was 32 degrees (4 to 75 degrees) preoperatively, 9 degree (1 to 26 degrees) postoperatively, and 9 degrees (1 to 24 degrees) at last follow-up. The width at mid-shaft of the tibia in the frontal plane was 1.1 cm (0.6 to 1.8 cm) preoperatively and 1.3 cm at the last follow-up (0.7 to 2.0 cm). In the sagittal plane, it was 1.25 cm (0.7 to 2.7 cm) preoperatively and 1.27 cm (0.8 to 2.8 cm) at the last follow-up. Ten patients did not require revision surgery during their follow-up. Sixteen mechanical complications occurred in 12 patients (12 fractures or deformities following a lack of overlap of the 2 rods at an average time of 4.9 years after the initial surgery, 3 prominence of the nail, 1 pseudarthrosis). No infectious complication was reported. Gillette Functional Score was 20.54/65. Fifteen patients were able to walk at last follow-up, and 18 had no painful discomfort. CONCLUSIONS: The tibial sliding elastic nailing technique provides satisfactory clinical and radiologic results over time. Performed in case of fracture or as a preventive treatment, it allows a good correction of angular deformations. It is particularly suitable for young patients with a narrow medullary shaft. LEVEL OF EVIDENCE: Level IV-therapeutic study.

Can Chiari Osteotomy Favorably Influence Long-term Hip Degradation in Multiple Epiphyseal Dysplasia and Pseudoachondroplasia?

BACKGROUND: Multiple epiphyseal dysplasia (MED) and pseudoachondroplasia (PSACH) are congenital skeletal disorders characterized by irregular epiphyses, mild or severe short stature and early-onset osteoarthritis which frequently affect the hips. The current study evaluates the long-term results of the Chiari osteotomy in MED and PSACH patients. METHODS: Twenty patients (14 MED and 6 PSACH) were retrospectively included. Clinical assessment used the Postel Merle d'Aubigné (PMA) score and the Hip disability and Osteoarthritis Outcome Score (HOOS). Risser index, Sharp angle, acetabular depth index, center-edge angle, Tönnis angle, and femoral head coverage were measured on the preoperative radiographs and at last follow-up. The Treble index, which identifies the hip at risk in MED patients, was also determined. Stulberg classification (grades I to V) was used to evaluate the risk of osteoarthritis in the mature hips.Statistical analyses determined differences between preoperative and postoperative data. The Kaplan Meier method was used to calculate the survival rate of the operated hips using total hip arthroplasty as the endpoint. RESULTS: Thirty-three hips which underwent a Chiari osteotomy were reviewed. The average follow-up was 20.1 years. The PMA scores were significantly better at last follow-up than preoperatively. All radiographic parameters significantly improved. Moreover, the Sharp angle, center-edge angle, and femoral head coverage improved to a normal value at hip maturity. All of the operated hips had a Treble index of type I. At hip maturity, a majority of hip were aspherical congruent (Stulberg grades of III and IV). The survival rate of the operated hips was 80.7% at 24 years postoperative. CONCLUSIONS: The Chiari osteotomy is a satisfying solution for severe symptomatic hip lesions in MED and PSACH patients. At long-term follow-up, this procedure lessens pain and improves hip function, which delays total hip arthroplasty indication. LEVEL OF EVIDENCE: Level IV.

Multicentric carpotarsal osteolysis syndrome: long-term follow-up of three patients.

Multicentric carpotarsal osteolysis (MCTO) is a rare skeletal disorder characterized by progressive carpal and tarsal destruction. The upper and lower limbs may be involved, leading to deformities and joint limitation. These anatomic features may be associated with progressive renal failure. The radiographs obtained during childhood showed a carpal and tarsal osteolysis and an asymmetrical involvement. Here, we report on the long-term clinical and radiological findings of three patients with skeletal manifestations of MCTO.

Surgical Treatment of Enchondromas of the Hand During Childhood in Ollier Disease.

PURPOSE: The objective of the present study was to evaluate the outcome of surgical treatment of hand lesions in Ollier disease (OD) carried out during childhood. METHODS: A retrospective review was carried out of 10 pediatric patients with hand involvement of OD, who had undergone surgery for metacarpal or phalangeal enchondromas. The technique comprised curettage and cortical bone reconstruction with corticoplasty, to restore a near-normal phalangeal volume. The range of finger motion (pulp-to-palm distance), the shortened Disabilities of the Arm, Shoulder, and Hand (QuickDASH) questionnaire score, cosmetic improvement, radiological findings (according to Tordai's classification), and recurrence were recorded after a mean follow-up of 7.5 years (range, 4-11.3 years). RESULTS: The mean age at surgery was 10.7 years (range, 6-14 years). Curettage was performed on 35 enchondromas, and 9 cavities were filled with a bone graft. The mean pulp-to-palm distance was significantly lower after surgery (from 1.5 cm to 0.25 cm; P < .05). The mean QuickDASH score was 3.84 (range, 0-11.4). A marked cosmetic improvement was noted for 83% of the hands. Three enchondromas recurred in 1 patient, requiring a second curettage. Fifty-seven percent of the cavities were completely filled with bone (Tordai stage 1) at last follow-up. The outcome did not depend on the presence or absence of a bone graft. CONCLUSIONS: Our results suggest that early surgical treatment comprising curettage and corticoplasty leads to good clinical, cosmetic, and radiological outcomes. Early surgical treatment of well-developed and/or symptomatic enchondromas of the hand in OD should be considered. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

'In-Out-In' K-wires sliding in severe tibial deformities of osteogenesis imperfecta: a technical note.

Severe infant osteogenesis imperfecta requires osteosynthesis. Intramedullary tibia's osteosynthesis is a technical challenge given the deformity and the medullar canal's narrowness. We describe an extramedullary technique: 'In-Out-In' K-wires sliding. We performed an anteromedial diaphysis approach. The periosteum was released while preserving its posterior vascular attachments. To obtain a straight leg, we did numerous osteotomies as many times as necessary. K-wires ('In') were introduced into the proximal epiphysis, and the medial malleolus ('Out') bordered the cortical and ('In') reach their opposite metaphysis. K-wires were cut, curved and impacted at their respective epiphysis ends to allow a telescopic effect. All tibial fragments are strapped on K-wires, and the periosteum was sutured over it. Our inclusion criteria were children with osteogenesis imperfecta operated before 6 years old whose verticalization was impossible. Seven patients (11 tibias) are included (2006-2016) with a mean surgery's age of 3.3 ± 1.1 years old. All patients received intravenous bisphosphonates preoperatively. The follow-up was 6.1 ± 2.7 years. All patients could stand up with supports, and the flexion deformity correction was 46.7 ± 14.2°. Osteosynthesis was changed in nine tibias for the arrest of telescoping with flexion deformity recurrence and meantime first session-revision was 3.8 ± 1.7 years. At revision, K-wires overlap had decreased by 55 ± 23%. Including all surgeries, three distal K-wires migrations were observed, and the number of surgical procedures was 2.5/tibia. No growth arrest and other complications reported. 'In-Out-In' K-wires sliding can be considered in select cases where the absence of a medullary canal prevents the insertion of intramedullary rod or as a salvage or alternative procedure mode of fixation. It can perform in severe infant osteogenesis imperfecta under 6 years old with few complications and good survival time.

Orthopedic and neurosurgical care of X-linked hypophosphatemia.

X-linked hypophosphatemia (XLH) is due to mutations in the PHEX gene leading to unregulated production of FGF23 and uncontrollable hypophosphatemia. XLH is characterized in children by rickets, short stature, waddling gait, and leg bowing of variable morphology and severity. Phosphate supplements and oral vitamin D analogs partially or, in some cases, fully restore the limb straightness. XLH patients may also be affected by premature, complete, or partial ossification of sutures between cranial bone, which could eventually result in cranial dysmorphia, decreased intracranial volume, and secondary abnormally high intracranial pressure with a cerebral compression. Our goal is to address the criteria and the management of the skeletal complications associated with XLH, mainly orthopedic and neurosurgical care, and reflect on decision-making and follow-up complexities.

Heterozygous FGFR1 mutation may be responsible for an incomplete form of osteoglophonic dysplasia, characterized only by radiolucent bone lesions and teeth retentions.

Non-ossifying fibromas are seen in different disorders recognizable by specific features. Indeed, osteoglophonic dysplasia (OD) is characterized by radiolucent bone lesions associated with severe short stature, dysmorphism and failure of dental eruption. This syndrome is caused by heterozygous activating mutations in the immunoglobulin-like D3 domain of the FGFR1 gene, encoding a tyrosine kinase. Here, we report three patients from the same family presenting with radiolucent bone lesions and teeth retentions. Exome sequencing allowed identification of a novel mutation c.917C > T, p. Pro306Leu in exon 7 of the FGFR1 gene. Our patients present with normal stature and no severe dysmorphism. This report describes a mild form of OD and expands the phenotype related to FGFR1 mutations. These findings emphasize the need to consider FGFR1 variants in the case of multiple non-ossifying bone lesions associated with dental eruption anomalies.

A new osteogenesis imperfecta with improvement over time maps to 11q.

Osteogenesis imperfecta (OI) is basically divided into four clinical types, I-IV. Type IV clearly represents a heterogeneous group of disorders. Here we describe two OI patients in the same family. They would typically be classified as having type IV, but are distinguishable from other OI type IV patients by the improving and resolving course of their disease. Mutation screening did not identify mutations affecting glycine codons or splice sites in the coding regions of the two collagen I genes. Genome-wide screening of DNA samples from the two homozygous patients identified one region of high concordance of homozygosity on chromosome 11 on the long arm (11q23.3-11q24.1).

Achondroplasia.

Achondroplasia (MIM 100800) is the most common non-lethal skeletal dysplasia. Its incidence is between one in 10,000 and one in 30,000. The phenotype is characterized by rhizomelic disproportionate short stature, enlarged head, midface hypoplasia, short hands and lordotic lumbar spine, associated with normal cognitive development. This autosomal-dominant disorder is caused by a gain-of-function mutation in the gene encoding the type 3 receptor for fibroblast growth factor (FGFR3); in more than 95% of cases, the mutation is G380R. The diagnosis is suspected on physical examination and confirmed by different age-related radiological features. Anticipatory and management care by a multidisciplinary team will prevent and treat complications, including cervical cord compression, conductive hearing loss and thoracolumbar gibbosity. Weight counselling, psychosocial guidance and professional integration programmes play an important role in the global quality of life of these patients and their families.

Coxa vara in chondrodysplasia: prognosis study of 35 hips in 19 children.

BACKGROUND: To better understand anatomical and functional outcomes of coxa vara in chondrodysplasia according to the initial presenting hip morphology, disease type, and impact of surgery. METHODS: Clinical and radiographic records of 19 children (35 hips) diagnosed with coxa vara and with osteochondrodysplasia were reviewed. We classified the hip radiographic findings into 2 groups: (a) group I, coxa vara with a fragmented and/or nonossified head; and (b) group II, coxa vara with a regular femoral head. Surgical indications in coxa vara included decreased range of hip motion (usually diminished abduction, extension, and internal rotation), coxa vara with progression documented on regular follow-up hip radiographs, and/or severe coxa vara with a Hilgenreiner epiphyseal angle (HEA) of 60 degrees or more. Follow-up was until the completion of growth and, for some patients, into early adulthood. Mean follow-up was 8 years. RESULTS: Twenty-five hips were operated on in 13 patients. In 23 hips, the procedure was a valgus osteotomy fixed by pins and wire. A pelvic extension osteotomy without valgus osteotomy was performed in one patient (2 hips). Coxa vara recurred in 7 hips. In 4 of these hips, repeat surgery with hypervalgus osteotomy was indicated to stop epiphyseal slipping (3 hips) or to improve the arc of motion (1 hip). Functional outcomes were poor in coxa vara associated with poor epiphyseal development (nonossified or fragmented epiphysis) as seen in spondyloepiphyseal dysplasia congenita, spondyloepimetaphyseal dysplasia, Kniest disease, and multiple epiphyseal dysplasia. Coxa vara with physeal instability as observed in spondylometaphyseal dysplasia resulted in deformity recurrence postoperatively during growth. In contrast, outcome was better in cases of coxa vara with nonphyseal/nonepiphyseal involvement, that is, good femoral head morphology, stable physis, and good articular cartilage, as seen in cases of metaphyseal dysplasia and cleidocranial dysplasia. CONCLUSIONS: Coxa vara with physeal and epiphyseal involvement and severe impairment of the articular cartilage has a poor prognosis even after reconstructive surgery. In coxa vara with an abnormal physis, there were numerous postsurgical recurrences of the deformity during growth if the physis was not stabilized at the time of valgus osteotomy. In these cases, we should delay osteotomy until an HEA greater than 60 degrees. Coxa vara in which only the metaphysis of the femoral neck is involved, the deformity is milder and often requires no treatment. Indications for surgery in this group are increasing coxa vara, Trendelenburg gait, or an HEA greater than 60 degrees.

[When to think of a constructional bone disease?]. / Quand penser à une maladie osseuse constitutionnelle ?

When to think of a constitutional bone disease?. Constitutional bone diseases are a heterogenous group of disorders, variably causing: growth anomalies, joint limitation and/or hypermobility, pain, bone frailty and/or dysmorphic elements in the craniofacial sphere and the extremities. Clinical examination, radiographies with a phosphocalcic test allow to guide the diagnosis. Medical therapy for these pathologies is most of the time symptomatic, combining painkillers, kinesitherapy, and functional and/or surgical orthopedic treatment. Genetic consultation is essential to confirm the diagnosis, possibly suggest the adequate molecular analysis, discuss the genetic counselling and suggest an outline of medical therapy.

Quand penser à une maladie osseuse constitutionnelle ?. Les maladies osseuses constitutionnelles constituent un groupe hétérogène d'affections entraînant de façon variable : une anomalie de croissance, des déformations osseuses, des limitations et/ou une hypermobilité articulaire, des douleurs, une fragilité osseuse et/ou des éléments dysmorphiques de la sphère cranio- faciale et des extrémités. L'examen clinique, les radiographies avec le bilan phosphocalcique permettent d'orienter le diagnostic. La prise en charge de ces pathologies est le plus souvent symptomatique, conjuguant des antalgiques, de la kinésithérapie, et des prises en charge orthopédiques fonctionnelles et/ou chirurgicales. La consultation de génétique est indispensable pour affirmer le diagnostic, éventuellement proposer l'étude moléculaire adéquate, parler du conseil génétique et proposer les grandes lignes de prise en charge.

Long-term outcome in Desbuquois dysplasia: a follow-up in four adult patients.

Desbuquois dysplasia is a rare chondrodysplasia characterized by short stature, joint laxity, and specific radiographic findings. We report the natural history of four patients (three boys and one girl) with Desbuquois dysplasia ages 16-22 years. The mean height in adulthood was 114 cm (-8.5 SD) with progressive deceleration of the growth curve from birth (-4 SD) to adulthood. Obesity was noted consistently and facial abnormalities were still present but less obvious than in childhood. Three of four patients had mental retardation of varying degree. Hyperlaxity was persistent but limited motion of various joints was also noted. Orthopedic complications included coxa vara or valga (3/4), scoliosis (3/4), marked lordosis (3/4), and ambulatory difficulties (3/4). Surgical treatment was necessary for all four patients, involving large joints, spine and hands. Other complications included acute open-angle glaucoma secondary to a congenital malformation of the angle in one case. In addition to consistent radiological findings, elevated greater trochanter, generalized osteoporosis especially of the spine, scoliosis and/or lordosis, wide metaphyses, flat epiphyses, and coxa vara or valga were part of the natural history of the disorder. Our study emphasizes the care of older patients with Desbuquois dysplasia.