Mucopolysaccharidoses (MPS) are a group of diseases characterized by abnormal accumulation of glycosaminoglycans (GAGs). Although there are differences among the various disease types, the osteoarticular system is always involved. The aim of the present study was to establish a framework for MPS-related orthopaedic manifestations and for their treatment. The authors, affiliated to three different Italian Orthopaedic Centres, report data taken from the literature reviewed in light of their accumulated professional experience. Bone alterations make up what is known as dysostosis multiplex, involving the trunk and limbs and with typical radiological findings. Joints are affected by pathological tissue infiltrations. The cervical spinal cord is involved, with stenosis and cervical and occipitocervical instability. In MPS there is a much higher incidence of scoliosis compared with healthy subjects without any particular distinctive feature. Kyphosis of the spine is more frequent and also more severe because of its possible neurological complications, and it is localized at the thoracolumbar level with a malformed vertebra at the top of the deformity. Evolving forms, and those associated with neurological damage, require anteroposterior spine fusion. The hip is invariably involved, with dysplasia affecting the femoral neck (coxa valga), the femoral epiphysis (loss of sphericity, osteonecrosis), and the femoral acetabulum which is flared. All these features explain the tendency to progressive hip migration. Genu valgum is often found (a deviation of the physiological axis with an obtuse angle opening laterally). This deformity is often localized at the proximal tibial metaphysis; it causes functional limitations and leads to an irregular erosion of the articular cartilage. In young patients who still have the growth plate, it is possible to execute a medial hemiepiphysiodesis, a temporary inhibition of cartilage growth, with progressive axis correction. In this paper, the characterisation of clinical features and the review of treatments are divided into separate sections based on the part of the body involved. The conclusions of each section are presented as a summary. One section discusses the high risk of anaesthesia-related complications requiring the collaboration of specifically trained personnel.

In all patients with mucopolysaccharidosis type I (MPS I), skeletal disease (dysostosis multiplex) is a prominent, debilitating, condition related complication that may impact strongly on activities of daily living. Unfortunately, it is not alleviated by treatment with hematopoietic cell transplantation (HCT) or enzyme replacement therapy (ERT). Although early kyphosis is one of the key features of dysostosis multiplex, there is no international consensus on the optimal management. Therefore, an international consensus procedure was organized with the aim to develop the first clinical practice guideline for the management of thoracolumbar kyphosis in MPS I patients. A literature review was conducted to identify all available information about kyphosis and related surgery in MPS I patients. Subsequently, a modified Delphi procedure was used to develop consensus statements. The expert panel included 10 spinal orthopedic surgeons, 6 pediatricians and 3 physiotherapists, all experienced in MPS I. The procedure consisted of 2 written rounds, a face-to-face meeting and a final written round. The first 2 rounds contained case histories, general questions and draft statements. During the face-to-face meeting consensus statements were developed. In the final round, the panel had the opportunity to anonymously express their opinion about the proposed statements. Eighteen case series and case reports were retrieved from literature reporting on different surgical approaches and timing of thoracolumbar kyphosis surgery in MPS I. During the face-to-face meeting 16 statements were discussed and revised. Consensus was reached on all statements. This international consensus procedure resulted in the first clinical practice guideline for the management of thoracolumbar kyphosis in MPS I patients, focusing on the goals and timing of surgery, as well as the optimal surgical approach, the utility of bracing and required additional assessments (e.g. radiographs). Most importantly, it was concluded that the decision for surgery depends not only on the kyphotic angle, but also on additional factors such as the progression of the deformity and its flexibility, the presence of symptoms, growth potential and comorbidities. The eventual goal of treatment is the maintenance or improvement of quality of life. Further international collaborative research related to long-term outcome of kyphosis surgery in MPS I is essential as prognostic information is lacking.

Background: Neonatal infectious spondylodiscitis is a rare bony infection with atypical clinical presentation and non-specific systemic symptoms. Diagnosis and treatment are often delayed resulting in vertebral destruction and severe complications. We retrospectively reviewed the case of an infant with infectious spondylodiscitis resulting in T12 body destruction and marked angular kyphosis. Case-report: A 4-week-old infant developed an infectious spondylodiscitis resulting in destruction of the T12 vertebral body and involvement of disc between T12 and L1. At 6 months of age, X-ray showed a marked thoracolumbar angular kyphosis above 50 Cobb degrees. Therefore, the patient underwent single time surgery with double anterior and posterior approach. At 9 years follow up, clinical and radiological findings show a stable correction with good aesthetic appearance. Conclusion: Neonatal spondylodiscitis could lead to marked kyphosis similar to the congenital one. Since treatment with casts and tutors is often inefficacious, prompt surgery should be considered. The double anterior and posterior approach is the best option in this condition.

Background: Hip dislocation is a common source of pain in children with neurologic impairment. When medical interventions fail, orthopedic surgery does not guarantee a definitive result as the displacement may continue postoperatively and a second operation is often required. Methods: Retrospective analysis of data regarding the safety and effectiveness of an intra-articular corticosteroid injection (IACI) in 11 patients, aged 15 ± 5 years old, collected through a telephonic questionnaire administered to parents. Results: 21 IACIs were performed, a mean number of 1.9 ± 1.5 times for each patient, at a mean age (of the first IACI) of 13.5 ± 5 years. According to the parents, the IACI significantly lowered the number of participants experiencing pain (82% reduction) and using analgesics (60% reduction). There was also a significant improvement in the children’s hip mobility (63% reduction in patients experiencing stiffness), decubitus (90% reduction in obligated positioning), behavior (80% reduction in lamenting or crying patients), sleep quality (87.5% reduction in patients awakening every night), and caregivers’ quality of life (91% reduction in worried parents). The mean reported duration of the IACIs’ benefit was 5.4 ± 2.4 months (range 1–9), with a positive correlation with the number of IACIs (r = 0.48; p-value = 0.04) and a negative correlation with the age at the first injection (r = −0.71; p-value = 0.02). The only reported adverse event was mild local swelling in one child. Conclusions: the IACI could represent a safe and effective intervention for painful hip dislocation, both before and after surgery, with a long-lasting benefit which seems to increase as multiple IACIs are performed.