Neurosurgical management of achondroplasia: a systematic review

The objective was to synthesize denominator-based evidence on indications, techniques, and postoperative outcomes of cervicomedullary decompression (CMD), spinal canal stenosis surgery, and cerebrospinal fluid (CSF) diversion for hydrocephalus in achondroplasia.

This systematic review followed PRISMA 2020 and was prospectively registered (PROSPERO CRD42025626915). MEDLINE (via PubMed), Embase, Scopus, Web of Science, and the Cochrane Library were searched from inception through November 2025. The authors included observational studies of patients with achondroplasia who underwent CMD, spinal canal stenosis surgery, or CSF diversion for hydrocephalus with extractable outcomes and definable denominators. Two reviewers independently screened studies and extracted data. Risk of bias was assessed using ROBINS-I. Random-effects single-arm meta-analyses were performed for prespecified endpoints (any improvement, complete resolution, and mortality) only in cohorts with fully categorizable symptom status.

The authors included 38 observational studies (1442 patients): 18 CMD studies with 600 patients, 18 spinal stenosis studies with 686 patients, and 4 hydrocephalus studies with 156 patients. No study was at low risk of bias. For CMD (mean age 3.5 years; mean follow-up 27.8 months), any improvement was observed in 93% (95% CI 84%-97%) of patients and complete resolution in 44% (95% CI 16%-77%), and pooled mortality was 0% (95% CI 0%-5%). For spinal stenosis (mean age 36.6 years; mean follow-up 53.1 months), any improvement was observed in 92% (95% CI 78%-97%) and complete resolution in 30% (95% CI 16%-51%), and pooled mortality was 1% (95% CI 0%-2%). Hydrocephalus management was predominantly ventriculoperitoneal shunting (74.4%), with endoscopic third ventriculostomy in 23.1%, but symptom outcomes were rarely classifiable (9.6%), precluding strategy-level inference.

CMD and spinal stenosis surgery were frequently followed by symptom improvement in published series, whereas complete resolution was variably defined and inconsistently reported. Hydrocephalus studies described practice patterns but lacked outcome reporting adequate for comparing diversion strategies. Validated patient-reported outcomes were rarely reported, limiting inference on health-related quality of life.