Progressive acetabular dysplasia in a boy with mucopolysaccharoidosis type IV A (Morquio syndrome): a case report

Clinical overview and outcome of the Stuve-Wiedemann syndrome: a systematic review

BACKGROUND

Stuve-Wiedemann syndrome (SWS) is a rare and severe genetic disease characterized by skeletal anomalies and dysautonomic disturbances requiring appropriate care. Peer support is mandatory to fill the lack of clinical recommendations in such rare diseases. We report a new case and provide the first systematic review of all previous published cases.

OBJECTIVE

To better describe the timeline of SWS and to improve paediatric management.

DATA SOURCES

SWS English publications available on Pubmed until 31/03/2021.

STUDY SELECTION

Case description combining typical osteo-articular and dysautonomic involvement (with 2 items by categories required for children < 2 years and 3 items > 2 years).

DATA EXTRACTION

Demographic, clinical, genetics and outcome data.

RESULTS

In our cohort of 69 patients, the median age at report was 32 months. Only 46% presented antenatal signs. Mortality rate is higher during the first 2 years (42% < 2 years; 10% > 2 years) mainly due to respiratory failure, pulmonary arterial hypertension appearing to be a poor prognosis factor (mortality rate 63%). After 2 years, orthopaedic symptoms significantly increase including joint mobility restriction (81%), spinal deformations (77%) and fractures (61%).

CONCLUSIONS

Natural history of SWS is marked by a high mortality rate before 2 years due to dysautonomic disturbances. A specialized multidisciplinary approach is needed to address these early mortality risks and then adapt to the specific, mainly orthopaedic, needs of patients after 2 years of age. Further research is required to provide clinical guidelines and improve pre-natal counselling.

Hip disease in Mucopolysaccharidoses and Mucolipidoses: A review of mechanisms, interventions and future perspectives

The hips are frequently involved in inheritable diseases which affect the bones. The clinical and radiological presentation of these diseases may be very similar to common hip disorders as developmental dysplasia of the hip, osteoarthritis and avascular necrosis, so the diagnosis may be easily overlooked and treatment may be suboptimal. Mucopolysaccharidosis (MPS) and Mucolipidosis (ML II and III) are lysosomal storage disorders with multisystemic involvement. Characteristic skeletal abnormalities, known as dysostosis multiplex, are common in MPS and ML and originate from intra-lysosomal storage of glycosaminoglycans in cells of the cartilage, bones and ligaments. The hip joint is severely affected in MPS and ML. Hip pathology results in limitations in mobility and pain from young age, and negatively affects quality of life. In order to better understand the underlying process that causes hip disease in MPS and ML, this review first describes the normal physiological (embryonic) hip joint development, including the interplay between the acetabulum and the femoral head. In the second part the factors contributing to altered hip morphology and function in MPS and ML are discussed, such as abnormal development of the pelvic- and femoral bones (which results in altered biomechanical forces) and inflammation. In the last part of this review therapeutic options and future perspectives are addressed.

Hip Dysplasia in Mucopolysaccharidosis Type IVA (Morquio A Syndrome) Treated by Proximal Femoral Valgization Osteotomy: A Case Report

Introduction

Morquio A syndrome or mucopolysaccharidosis type IVA (MPS IVA) is a progressive lysosomal storage disorder caused by an N-acetylgalactosamine-6-sulfatase deficiency. The abnormal metabolism of glycosaminoglycans among other medical problems leads to various skeletal disorders caused by a dysfunction of endochondral ossification of epiphyseal cartilage. Severe hip dysplasia is common and can lead to pain and impaired mobility.

Case Report

We report on a 15-year-old girl suffering from MPS IVA. At the age of 5 years, hip pain and a reduced walking distance were described for the 1sttime. At the age of 9 years, acetabulofemoral dysplasia associated with genuavalga was diagnosed. After pre-operative assessment of the hips including plain radiographs, magnetic resonance imaging, and arthrography with dynamic testing a valgization osteotomy of the proximal femur in combination with a shelf acetabuloplasty was performed. The patient was followed for 6 years with a stable hip joint and without any sign of redislocation.

Conclusion

Some treatment strategies of hip dysplasia in patients with MPS IVA are described in the literature. The techniques used for congenital hip dysplasia, varisation of the femur in combination with Pemberton, Salter, or shelf acetabuloplasty, are widely reported. Nevertheless, resubluxations were described in some cases. The well-known surgical procedure with valgization of the proximal femur is not reported in literature for MPS IVA patients. In our opinion, dynamic testing with arthrography should strongly be considered for this particular problem before surgical intervention. Pathology-related decisions should be made under consideration of the different surgical techniques.

Orthopedic management of the extremities in patients with Morquio A syndrome

BACKGROUND

Musculoskeletal involvement in Morquio A syndrome (mucopolysaccharidosis IVA; MPS IVA) contributes significantly to morbidity and mortality. While the spinal manifestations of the disorder have received considerable attention in the literature, there have been few reported studies to date to guide the management of the orthopedic problems associated with the lower and upper extremities.

PURPOSE

The objective was to develop recommendations for the management of the extremities in patients with Morquio A syndrome.

METHODS

A group of specialists in orthopedics, pediatrics and genetics with experience in the management of Morquio A patients convened to review and discuss current clinical practices and to develop preliminary recommendations. Evidence from the literature was retrieved. Recommendations were further refined until consensus was reached.

RESULTS AND CONCLUSIONS

This present article provides a detailed review and discussion of the lower and upper extremity deformities in Morquio A syndrome and presents recommendations for the assessment and treatment of these complications. Key issues, including the importance of early diagnosis and the implications of medical therapy, are also addressed. The recommendations herein represent an attempt to develop a uniform and practical approach to managing patients with Morquio A syndrome and improving their outcomes.

The lower extremity in Morquio syndrome

BACKGROUND

The modalities and results of surgical intervention in the lower extremity in children with Morquio syndrome type A [mucopolysaccharidosis-IV (MPS-IVA)] have not been well described. The aims of this study are to define the lower extremity deformities, and describe the results of intervention in MPS-IVA patients.

METHODS

Retrospective chart and radiograph review of 23 MPS-IVA patients with a minimum follow-up of >2 years. Patients were divided into no intervention and surgical groups. Demographic data, surgical details, clinical results, and complications were recorded. Standard lower extremity radiographic measurements made on standing radiographs at initial presentation, preoperatively (in surgical group), and at the final follow-up were used to study the deformities and effects of hip, knee, and ankle surgery. Descriptive statistics were performed.

RESULTS

There were 11 boys and 12 girls. The average age at presentation was 6.8±3.4 years and at the last visit was 13.5±5 years with a mean follow-up of 6.7±3.7 years. Progressive hip subluxation, genu valgum, and ankle valgus were observed in all patients without intervention. Twenty patients had a total of 159 lower extremity surgical procedures (average, 8 procedures per patient). There were 61 hip, 78 knee, and 20 ankle procedures. Surgery resulted in improvement of the center edge angle, femoral head coverage, lateral distal femoral angle, medial proximal tibial angle, tibiofemoral angle, and lateral distal tibial angle. Mechanical axis of the lower extremities improved after intervention. Six patients (12 hips) had recurrence of hip subluxation after acetabular osteotomies and/or femoral varus derotation osteotomy, and 8 patients (16 knees) had postoperative genu valgum recurrence requiring subsequent intervention. There was no recurrent hip subluxation after shelf acetabuloplasty.

CONCLUSIONS

Progressive hip subluxation, genu valgum, and ankle valgus were seen and often needed surgery. After shelf acetabuloplasty and varus derotation osteotomy, there was no recurrent hip subluxation. Recurrence after genu valgum correction was common.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Pathogenesis of skeletal and connective tissue involvement in the mucopolysaccharidoses: glycosaminoglycan storage is merely the instigator

The mucopolysaccharidoses (MPSs) are a series of rare genetic disorders in which progressive bone and joint disease represents a key source of morbidity for patients. The recent introduction of enzyme replacement therapy for many of the MPSs has led to a need for increased physician awareness of these rare conditions in order to ensure that treatment is initiated at a time that leads to optimal benefit for patients. In addition, the current experiences of the clinical responsiveness of patient's symptoms to enzyme replacement approaches have also fuelled an interest in the development of alternative and adjunctive therapeutic approaches directed particularly to the rheumatological aspects of disease. Understanding the underlying pathogenesis of the MPSs is a key element for advancements in both of these areas. This review highlights the current knowledge underlying the pathophysiology of disease symptoms in the MPSs and underscores the importance and role of pathogenic cascades.