Spinal manifestations of skeletal dysplasias

Best practice guidelines for management of spinal disorders in skeletal dysplasia

BACKGROUND

Disorders of the spine present a common and difficult management concern in patients with skeletal dysplasia. Due to the rarity of these conditions however, the literature, largely consisting of small, single institution case series, is sparse in regard to well-designed studies to support clinical decision making in these situations.

METHODS

Using the Delphi method, an international, multi-disciplinary group of individuals, with significant experience in the care of patients with skeletal dysplasia, convened to develop multi-disciplinary, "best practice" guidelines in the care of spinal disorders in patients with skeletal dysplasia.

RESULTS

Starting with 33 statements, the group a developed a list of 31 "best practice" guidelines.

CONCLUSIONS

The guidelines are presented and discussed to provide context for clinicians in their decision making in this often-challenging realm of care.

Brace treatment of thoracolumbar kyphosis in spondylometaphyseal dysplasia with restoration of vertebral morphology and sagittal profile: a case report

BACKGROUND CONTEXT

The Kozlowski type of spondylometaphyseal dysplasia (SMD-K) is characterized by vertebral and metaphyseal abnormalities. The longitudinal evolution of thoracolumbar kyphosis associated with vertebral anomalies in SMD-K is unclear.

PURPOSE

To document the longitudinal changes in sagittal alignment and vertebral morphology in a patient with SMD-K treated nonoperatively with a Milwaukee brace.

STUDY DESIGN/SETTING

Case report.

PATIENT SAMPLE

Patient with SMD-K having multiple vertebral anomalies and a thoracolumbar kyphosis.

METHODS

A girl with SMD-K seen initially at 21 months old was followed for 14 years. She presented with thoracolumbar kyphosis associated with multiple vertebral anomalies consisting primarily of hypoplasia at L1, beaking at L2, and ovoid shape of adjacent vertebrae. The patient was treated with a Milwaukee brace and followed until she was 16 years old.

RESULTS

After initiation of brace treatment, the thoracolumbar kyphosis gradually resolved and she had a normal sagittal alignment at last follow-up. Normal vertebral morphology was also completely restored in the sagittal plane. The patient developed a main thoracic scoliosis that did not require additional treatment.

CONCLUSIONS

Nonoperative treatment with bracing can be attempted in patients with SMD-K affected by thoracolumbar kyphosis and multiple vertebral anomalies, because full restoration of normal sagittal alignment and vertebral morphology is possible.

Severe neurological complications in skeletal dysplasias: two case reports

Skeletal dysplasias form a diverse and genetically heterogeneous group of disorders, but also share many clinical and radiographic features. We describe two illustrative cases and provide a short review of the literature on the neurological complications associated with various groups of skeletal dysplasias. These two cases illustrate that management of skeletal dysplasias requires a multidisciplinary approach, aimed at preventing or minimizing medical complications. Follow-up should include regular comprehensive neurological evaluation, as neurological complications can be severe and are often treatable if diagnosed at an early stage.

Expression of cartilage oligomeric matrix protein (COMP) by embryonic and adult osteoblasts

Cartilage oligomeric matrix protein has been implicated as an important component of endochondral ossification because of its direct effects on chondrocytes. The importance of this protein for skeletal development and growth has been recently illustrated by the identification of mutations in cartilage oligomeric protein genes in two types of inherited chondrodysplasias and osteoarthritic phenotypes: multiple epiphyseal dysplasia and pseudoachondroplasia. In the present study, we report the presence of cartilage oligomeric protein in embryonic and adult osteoblasts. A foot from a 21-week-old human fetus, subchondral bone obtained from knee replacement surgery in an adult patient, and a limb from a 19-day-postcoital mouse embryo were analyzed with immunostaining and in situ hybridization. In the human fetal foot, cartilage oligomeric protein was localized to osteoblasts of the bone collar and at the newly formed bone at the growth plate and bone diaphyses. Immunostaining was performed on the adult subchondral bone and showed positive intracellular staining for cartilage oligomeric protein of the osteoblasts lining the trabecular bone. There was no staining of the osteocytes. Immunostaining of the mouse limb showed the most intense staining for cartilage oligomeric protein in the hypertrophic chondrocytes and in the surrounding osteoblast cells of the developing bone. Cartilage oligomeric protein mRNA and protein were detected in an osteoblast cell line (MG-63), and cartilage oligomeric protein mRNA was detected from human cancellous bone RNA. These results suggest that the altered structure of cartilage oligomeric protein by the mutations seen in pseudoachondroplasia and multiple epiphyseal dysplasia may have direct effects on osteoblasts, contributing to the pathogenesis of these genetic disorders.