Aim: To determine that the aetiology of cord compression in mucopolysaccharidoses (MPS) type VI. To illustrate the variability of this complication of mucopolysaccharidoses even within families. To report the youngest MPS VI patient yet described with spinal cord compression and to present the technique and results of spinal stabilisation.

Method: The course, clinical findings and management of three patients with MPS VI and two with MPS IV were reviewed.

Results: The patients with MPS VI demonstrated that the pathogenesis of spinal cord compression in this condition is complex, with elements of joint instability, bony disease and soft tissue compression. Two of the patients with MPS VI are siblings: the younger sibling was 30 months old when she required surgery. She is the youngest reported patient with this complication of MPS VI. The patients with MPS IV are presented to illustrate similarities and differences in the pathogenesis of the same problem in the two disorders. Results of cervical spine stabilisation were found to be satisfactory.

Conclusions: In both MPS IV and MPS VI spinal cord compression may be multi-factorial. This complication of the mucopolysaccharidoses needs to be considered even when the patient is very young.

The benefits of total hip arthroplasty (THA) may be significantly magnified in children, since the improvement in quality of life has a far greater exposure time and occurs during key developmental stages which may help to maximise lifetime achievement. The purpose of this study is to describe implant survival and patient reported outcomes (PROMS) in a cohort of children following THA. Retrospective cohort review of all patients treated with THA in a single centre. Routine data analysis did not require ethical approval. Survival was estimated using Kaplan-Meier and PROMs were recorded (EQ5D-S, Oxford hip score and modified Harris Hip Score) in a sub-group of patients. 66 hips in 47 patients with a median age of 16 years (range 10 to 19 years) underwent THA between 1971 and 2023. 57% (38/68) patients were female, the commonest indications were Mucopolysaccharidoses n = 15, Stills disease (n=15), and Avascular necrosis (n=12). 27 (41%) of constructs were cemented, 5 (8%) were hybrid, and 34 (51%) were cementless. 30 stems were custom made cementless stems. Median follow up was 3.8 years (range 0–34 years). Implant survival was 87% at 10 years, 61.6% at 20 years and 52.8% at 30 years. PROMS demonstrated mean preoperative OHS was 12, preoperative MHHS was 23 and EQ5Ds VAS of 38. PROMS improved steadily overtime with mean OHS of 43, MMHS of 75 and EQ5Ds VAS of 89 at one year. THA was associated with a very large change in patient reported hip function and quality of life. In this study, THA delivered a long-lasting solution to hip pain with survival similar to that seen in patients undergoing THA in the fourth and fifth decades of life. Socioeconomic benefits of THA need further investigation to establish treatment guidelines for children suffering with hip pain