Orthopaedic conditions in Ras/MAPK related disorders.

BACKGROUND: The RAS/MAPK disorders [Noonan syndrome, cardiofaciocutaneous (CFC) syndrome, Costello syndrome, and Leopard syndrome] are heterogenous conditions with phenotypic overlap. Their orthopaedic manifestations are not well defined, and their phenotypic similarity makes differentiating them difficult. METHODS: We prospectively evaluated 60 individuals: 26 with Noonan syndrome, 32 with CFC syndrome, and 2 with Costello syndrome. Each individual underwent a structured orthopaedic history and physical evaluation by an orthopaedic surgeon, and a syndromic evaluation by a geneticist. RESULTS: All groups had a high prevalence of scoliosis (8/26 Noonan syndrome, 8/32 CFC syndrome, and 1/2 Costello). Those with Noonan syndrome or CFC syndrome had a high instance of serious cervical spine disorders, including cervical stenosis, Arnold-Chiari malformation, and syringomyelia in the Noonan syndrome individuals and hydrocephalus, cervical stenosis, torticollis, and Arnold-Chiari in the CFC syndrome individuals. Noonan syndrome manifestations included chronic pain (n=21), pes planus (n=11), pes cavus (n=5), hip contractures (n=5), hand dysfunction (n=3), and hip dysplasia (n=2). Manifestations of CFC syndrome included pes planovalgus (n=20), knee flexion contractures (n=7), hip dysplasia (n=5), elbow flexion contractures (n=4), pedal calluses (n=4), toe crowding (n=4), and hip contractures (n=4). Individuals with Costello syndrome had shorter stature than the other groups and were prone to have hand contractures. CONCLUSIONS: Orthopaedic manifestations are frequent and diverse in Ras/MAPK disorders and can be used in phenotypic differentiation between these disorders. LEVEL OF EVIDENCE: II.

Shelf and/or reduction and containment surgery.

Hinge abduction occurs early in the fragmentation stage of Legg-Calvé-Perthes disease and should be suspected when abduction and internal rotation are lost. It can be confirmed by an AP radiograph in abduction and internal rotation in which the ossific nucleus is not covered by the acetabulum. An arthrogram can then yield greater information regarding the reversibility of the hinge abduction. Hinge abduction should be considered a contraindication to containment by redirectional pelvic or femoral varus osteotomy. However, good results have been reported with acetabular augmentation via shelf procedures or Chiari osteotomies. Valgus femoral osteotomies have also been beneficial in the treatment of the Legg-Calvé-Perthes hip with hinge abduction.

Precocious osteoarthritis in a family with recurrent COL2A1 mutation.

OBJECTIVE: To examine the genotypic and phenotypic characteristics of a Micronesian kindred with autosomal dominant precocious osteoarthritis (OA). METHODS: We reviewed records and radiographs of 3 index patients and their parents, administered questionnaires to 16 additional kindred members, performed whole-genome scans of 24 family members, and sequenced relevant genes from 16 family members. RESULTS: The kindred displayed early onset OA, enlarged epiphyses, platyspondyly, and brachydactyly with dysplastic findings consistent with mild spondyloepiphyseal dysplasia. Genetic analysis revealed an arginine to cysteine substitution at position 75 of the collagen 2A1 gene, a mutation that has been described in 4 other geographically distinct families. The major phenotypic differences among the families were in height (ranging from short to tall) and hearing loss noted in 3 of the 5 families. CONCLUSION: The presence of the COL2A1 Arg75Cys mutation in 5 geographically distinct areas helps to confirm a potential mutational hotspot. The diverse phenotypic spectrum suggests that modifier genes and environmental factors play a role in the expression of this mutation.

Treatment of chronic osteomyelitis in children resistant to previous therapy.

Patients admitted to the authors' institution with tibial osteomyelitis between 1978 and 1998 were reviewed. The purpose of this study was to determine the incidence, etiology, treatment, and outcome in chronic pediatric tibial osteomyelitis. The authors describe their treatment of chronic osteomyelitis in children resistant to previous therapeutic modalities. Thirty patients were identified with a mean age of 8.5 years at diagnosis. Mean age at admission was 9.6 years, indicating more than a 1-year duration of disease. Follow-up averaged 2.3 years. Patients underwent 97 procedures, averaging 3.2 procedures per patient. Hospital stay ranged from 2 weeks to 18 months, with an average stay of 4.7 months. Seventy-seven percent of patients were culture-positive, and 78% of positive cultures identified Staphylococcus aureus as the causative pathogen. Eighty percent of patients had a good outcome, 13% had a fair outcome, and there were no poor results. Patients with large tibial defects obtained good results with both tibiofibular synostosis and Ilizarov distraction osteogenesis. The authors describe the only reported group of pediatric patients successfully treated using Ilizarov bone transport for bony tibial defects due to osteomyelitis.