Stand-alone craniocervical decompression is feasible in children with mucopolysaccharidosis type I, IVA, and VI

Background context: In patients with mucopolysaccharidosis (MPS), glycosaminoglycan deposits in the dura mater and supporting ligaments cause spinal cord compression and consecutive myelopathy, predominantly at the craniocervical junction. Disease characteristics of craniocervical stenosis (CCS) in patients with MPS differ profoundly from other hereditary and degenerative forms. Because of high periprocedural morbidity and mortality, patients with MPS pose a substantial challenge to the inexperienced medical care provider. As literature remains scarce, we present our experience with a large cohort of patients with MPS treated for CCS without atlanto-occipital instrumentation.

Purpose: The present study aimed to describe a safe and least traumatic approach for treating CCS in children with MPS, avoiding primary instrumentation.

Study design: This is a prospective follow-up (cohort) study.

Patient samples: We report 15 consecutive patients with CCS related to MPS, who were treated with stand-alone cervical decompression.

Outcome measures: Myelopathy was assessed using magnetic resonance imaging (MRI), somatosensory evoked potentials, and clinical evaluation. Cervical instability was evaluated using plain x-ray and MRI. The disability status is quantified using either the Karnofsky or Lansky Performance Score.

Methods: We describe 15 consecutive patients treated with craniocervical decompression. Data were collected prospectively. The mean follow-up is 6 years (5 standard deviation). The technique and treatment principles are described.

Results: The overall clinical outcome in this patient cohort is good (mean Karnofsky Performance Score of 80). No patient developed signs of C0-C1-C2 instability or progressive myelopathy. Restenosis occurred in seven patients, requiring a total of eight reoperations.

Conclusions: Surgery in patients with MPS is associated with high morbidity and mortality of up to 4.2%. Because of the unique nature of the disease, recurring stenosis is inevitable. To shorten the procedure time and simplify the anticipated reoperation, we provide data that craniocervical decompression is feasible without the necessity of primary osteosynthesis. In the absence of craniocervical instability, decompression surgery without occipitocervical stabilization yields good postoperative results and challenges the long-standing paradigm of prophylactic craniocervical fixation.