Cemented revision total hip arthroplasty with impaction bone grafting in Gaucher's disease

Total hip replacement in Gaucher's disease: effects of enzyme replacement therapy

Total hip replacement in patients with Gaucher's disease with symptomatic osteonecrosis of the femoral head is controversial because of the high early failure rates. We describe four patients who had an uncemented total hip replacement following enzyme replacement therapy for a median of two years and one month (1 to 9.8 years) prior to surgery, and who remained on treatment. At operation, the bone had a normal appearance and consistency. Histopathological examination showed that, compared with previous biopsies of untreated Gaucher's disease, the Gaucher cell infiltrate had decreased progressively with therapy, being replaced by normal adipose tissue. The surfaces of viable bone beyond the osteonecrotic areas showed osteoblasts, indicating remodelling. In one case acetabular revision was carried out after 11 years and eight months. The three remaining patients had a mean follow-up of six years and four months (3.3 to 12 years). We recommend initiating enzyme replacement therapy at least one to two years prior to total hip replacement to facilitate bone remodelling and to allow implantation of uncemented components in these young patients.

Musculoskeletal complications encountered in the lysosomal storage disorders

The lysosomal storage disorders are a heterogeneous group of inherited metabolic diseases resulting from defects in the degradation or transport of several distinct by-products of cellular turnover. The various subtypes are characterized by multi-systemic involvement; the wide range in patient ages at symptom onset is only partly explained by the underlying mutation(s). Neurodegenerative features and musculoskeletal complications are often seen in the most severe variants, and are features of the disease that have the most significant impact on patients' physical and functional well-being. Until recently, the care of affected individuals relied mainly on palliative or supportive measures. The introduction of therapies directed at correcting the primary defect (i.e., deficient enzyme activity) in several of these disorders has led to modification of the phenotype and natural history or disease course; however, clinical problems arising from brain and bone involvement remain major sources of morbidity. Factors that might influence therapeutic outcome include pre-existing pathology at the time of treatment initiation, drug access to tissues sites of pathology, and - in the case of enzyme therapy - antibody formation. Increasing understanding of the pathogenesis or relevant mechanism(s) of diseases is providing insights into additional therapeutic targets, enabling the potential for optimized patient outcomes with the use of adjunctive or supplemental agents. Physical and occupational therapy remain critical components of a comprehensive approach to patient care.

Musculoskeletal complications associated with lysosomal storage disorders: Gaucher disease and Hurler-Scheie syndrome (mucopolysaccharidosis type I)

PURPOSE OF REVIEW

Enzyme therapy for lysosomal storage disorders directed at correcting the underlying cause of disease represents the most significant recent advance in patient management. This review focuses on two disease groups: glycosphingolipidoses and mucopolysaccharidoses. Specifically, Gaucher disease and Hurler-Scheie syndrome have been selected as the prototypical disorder for each respective class.

RECENT FINDINGS

Musculoskeletal complications are encountered in several of the lysosomal storage disorders and often represent a major source of extraneurologic morbidity, particularly in the subacute or chronic variants. Enzyme therapy has led to improvements in physical and functional well-being. However, bone involvement remains a recalcitrant feature, especially among patients with established disease before institution of therapy.

SUMMARY

Early diagnosis and appropriate timely intervention are critical in achieving the best therapeutic results. A better understanding of the fundamental mechanisms of bone pathology may enable the identification of complementary approaches (eg, the use of bisphosphonates for severe osteopenia) for optimized outcomes. Symptomatic care and rigorous physical and occupational therapy remain critical components of a comprehensive management approach.