Many medical problems have musculoskeletal implications. This section discusses some of the more common of those diagnoses, including hemophilia, sickle cell disease, and endocrine and metabolic disorders such as rickets and lysosomal storage disorders.
Hemophilia is a genetic disorder characterized by abnormal blood clotting secondary to congenital deficiency of clotting factors VIII and IX. It may result in musculoskeletal problems by way of hemophilic arthropathy and intramuscular hemorrhage. Hemophilic arthropathy occurs through spontaneous bleeding into a weight-bearing joint, resulting in cartilage degeneration and arthrosis as well as asymmetric growth stimulation and deformity.
Sickle cell disease is inherited in an autosomal dominant fashion and is characterized by production of abnormal hemoglobin. This results in reduced oxygen delivery to tissues and can lead to multiple musculoskeletal manifestations, including painful bone infarcts, osteomyelitis, avascular necrosis, and vertebral compression fractures.
Metabolic bone diseases, such as rickets, occur due to abnormal calcium and phosphate metabolism. Rickets occurs in many forms, including vitamin D deficiency, vitamin D resistance, hypophosphatemic rickets, and renal osteodystrophy. Regardless of the cause, the result is inadequate calcification of bone and cartilage, resulting in bone pain and deformity.
The most common lysosomal storage disease is Gaucher’s disease, an autosomal recessive condition characterized by a deficiency in the enzyme beta-glucocerebrosidase. In Gaucher’s disease, there is an accumulation of glucocerebrosides, which contain glucose, in the tissues. This results in musculoskeletal manifestations that include bone deformity secondary to bone marrow infiltration, avascular necrosis, bone pain, pathologic fracture, and osteomyelitis.