Skeletal Dysplasias & Dwarfisms
Achondroplasia – or dwarfism, is a genetic condition resulting in abnormally short stature and disproportionately short limbs relative to the body's trunk and rhizomelic disproportion of the limb segments (relating to the hip or shoulder joints). Associated deformities include genu varum (bowlegs), genu valgum (knock knees), hip flexion deformity with compensatory hyperlordosis (exaggerated lumbar curve) of the spine and spinal stenosis (narrowing), dislocated radial head, flexion deformity of the elbow and trident hand. We perform extensive limb lengthening (ELL) for stature and for restoration of proportion of the limbs to the trunk, in which the upper to the lower bone segments (femur to tibia, humerus to forearm) is combined with correction of deformities of the ankles, knees, hips, elbows and hands. The correction of the hip deformity indirectly improves the hyperlordosis and spinal stenosis.
Cartilage Hair Hypoplasia (McKusick Syndrome) – is a disorder of bone growth resulting in short stature and other skeletal abnormalities as well as fine, sparse hair and compromised immune system function. These patients have disproportionate dwarfism but are usually shorter than achondroplastic dwarves. We successfully treat them by extensive limb lengthening of both femurs and tibias.
Chondroectodermal Dysplasia – also known as Ellis-van Creveld Syndrome. It is an autosomonal (genetically passed through both parents) recessive skeletal dysplasia that results in short-limbed disproportionate dwarfism. The most severe deformity is the knock knee deformity due to lack of development of the lateral plateau of the tibia. We perform a special intra-articular osteotomy (bone cutting inside the joint or bone) to elevate the lateral tibial plateau.
Congenitial Pseudarthosis of the Tibia – a condition in which the tibia develops a fracture that does not heal. This is probably a disease of the periosteum (the tissue covering the bone). The periosteum essentially strangles the underlying bone leading it to become thinner and also fracture. Over half of all cases have neurofibromatosis. The other half are idiopathic (no known cause) or related to fibrous dysplasia. We treat this with pharmacologic treatment using biphosphonates to prevent bone absorption by the osteoclast cells, as well as surgery to fix the bone with a rod and bone as well as periosteal graft and external fixator.
Diastrophic Dwarfism – a skeletal dysplasia characterized by scoliosis (abnormal lateral curvature of the spine), hitchhiker thumb due to shortening of the first metacarpal bone, cleft palate, malformed ear with calcification, and clubbed foot. We treat these patients with reconstruction of the hip, knee, and foot. Lengthening is not as common in this group due to the severe joint problems.
Fibrous Dysplasia – a bone disorder in which scar-like (fibrous) tissue grows in place of normal bone, weakening the bone, and often leading to deformity, fracture, and leg length difference. We treat this condition by correcting the deformity and in some cases by removal of the benign tumors and bone grafting.
Hurler's Disease – a hereditary disease characterized by severe abnormalities in the development of skeletal cartilage and bone often resulting in dwarfism and limb deformities. We correct the limb deformities associated with this condition.
Hypochondroplasia – a form of dwarfism similar to but milder than achondroplasia, (see also) and also characterized by disproportion of the limbs to the trunk and rhizomelia (disproportion of the tibia to the femur and the forearm to the humerus). Unlike achondroplasia, it involves less facial malformation and less spinal stenosis (narrowing) and lumbar hyperlordosis (exaggerated curvature of the lumbar spine). We treat these patients with extensive limb lengthening techniques for the femur, tibia and humerus similar to those used for achondroplasia. The only difference is that for hypochondroplasia we do less lengthening in amount and less deformity correction.
Madelung's Deformity – is a deformity of the wrist where part of the distal radius does not develop properly leading to subluxation (partial dislocation) of the wrist bones between the radius and ulna. The distal joint between the radius and ulna is dislocated leading to a prominent bump from the head of the ulna. Many cases are hereditary, some are related to Mesomelic Dysplasia. We treat this by opening the wrist joint from the palmer side and performing a complicated intra-articular osteotomy (bone cutting inside the joint) to elevate the depressed part of the radius and reduce the wrist bones into a joint combined with a second osteotomy to realign the lower radius and fix it with a metal plate. We combine the osteotomies with reduction and ligamentous reconstruction of the distal radio-ulnar joint.
Pseudoachondroplasia – a severe type of dwarfism characterized by joint laxity and severe deformities affecting the hips, knees and ankles. Realignment of the joints is the first priority. Extensive limb lengthening can be done with neutralization of joint forces by extending the external fixators (device) across the joints.
Spondyloepiphyseal Dysplasia – a severe type of dwarfism in which the cartilage of the joints is very deformable leading to deformities of the hips, knees and ankles. In the hip it can mimic AVN. (See AVN - avascular necrosis). Surgery to cover and reshape the hips and realign the knees and ankles is often warranted. Lengthening for stature can be done in modest amounts.