The mucopolysaccharidoses (MPS) are a group of inherited lysosomal storage disorders with clinical manifestations relevant to the orthopaedic surgeon. Our aim was to review the recent advances in their management and the implications for surgical practice.

The current literature about MPSs is summarised, emphasising orthopaedic complications and their management.

Recent advances in the diagnosis and management of MPSs include the recognition of slowly progressive, late presenting subtypes, developments in life-prolonging systemic treatment and potentially new indications for surgical treatment. The outcomes of surgery in these patients are not yet validated and some procedures have a high rate of complications which differ from those in patients who do not have a MPS.

The diagnosis of a MPS should be considered in adolescents or young adults with a previously unrecognised dysplasia of the hip. Surgeons treating patients with a MPS should report their experience and studies should include the assessment of function and quality of life to guide treatment.

Cite this article: Bone Joint J 2017;99-B:1132–9

Osteoarticular infections in paediatric population are primarily hematogenous in origin, although cases secondary to penetrating trauma, surgery or contiguous site are also reported. Despite being rare, numerous studies report infection relapse rates around 5 %. Osteomyelitis complications in children include septic arthritis, osteonecrosis of the bone segment, impaired growth. 7 years old male patient presented with history of traffic injury in January 2004. He sustained closed diaphyseal fracture of the right femur initially treated by elastic osteosynthesis. Four years after traffic injury he was diagnosed at our Institution of chronic femoral Osteomyelitis with positive cultures for methicillin sensible Staphylococcus aureus, requiring multiple surgical debridements and systemic antibiotic therapy. Five years follow- up the patient developed valgus deformity of his right knee (mechanical axis 11° genu valgum) with limb length discrepancy of 15 mm, intermalleolar distance of 15 cm and bone edema in external compartment of the knee (MRI). At this time the patient did not present any recurrence of septic process with normalization of laboratory parameters (ESR and CRP) and clinically asymptomatic. In February 2014, at the end of growth, a distal femoral varus osteotomy was used to treat valgus knee malalignment. Medial closing wedge osteotomy was performed satisfactorily using Tomofix® Osteotomy System (DePuySynthes). 18 months follow- up after varus osteotomy the patient progressed satisfactorily without pain and a normal function of his right knee. Correction limb length discrepancy was achieved (5 mm) with a normal alignment of his right limb (mechanical axis 3° genu valgum). Although Osteomyelitis is not very frequent in children population, its treatment requires not only prolonged antibiotic therapy but also multiple surgical debridements. We recommend monitoring over a long period of time children affected with Osteomyelitis in order to prevent and treat correctly impaired growth

Rebound growth after hemiepiphysiodesis may be a normal event, but little is known about its causes, incidence or factors related to its intensity. The aim of this study was to evaluate rebound growth under controlled experimental conditions.

A total of 22 six-week-old rabbits underwent a medial proximal tibial hemiepiphysiodesis using a two-hole plate and screws. Temporal growth plate arrest was maintained for three weeks, and animals were killed at intervals ranging between three days and three weeks after removal of the device. The radiological angulation of the proximal tibia was studied at weekly intervals during and after hemiepiphysiodesis. A histological study of the retrieved proximal physis of the tibia was performed.

The mean angulation achieved at three weeks was 34.7° (standard deviation (sd) 3.4), and this remained unchanged for the study period of up to two weeks. By three weeks after removal of the implant the mean angulation had dropped to 28.2° (sd 1.8) (p < 0.001). Histologically, widening of the medial side was noted during the first two weeks. By three weeks this widening had substantially disappeared and the normal columnar structure was virtually re-established.

In our rabbit model, rebound was an event of variable incidence and intensity and, when present, did not appear immediately after restoration of growth, but took some time to appear.

Cite this article: Bone Joint J 2015;97-B:862–8.

Objectives

The development of tibiofemoral angle in children has shown ethnic variations. However this data is unavailable for our population.

Introduction. It is recommended that the ankle be held in dorsiflexion at the time of placement of syndesmosis screw. We assessed the validity of this recommendation. Materials and methods. A two-part roentgenographic and computerised analysis of distal tibiofibular syndesmosis. The first part involved recruitment of 30 healthy adult volunteers. The second part involved 15 ankle fractures with syndesmotic injury requiring syndesmosis screw placement. In the first part individuals maximally dorsiflexed and plantarflexed their ankles in a specialised jig for standardisation. Mortice views were taken and intermalleolar distance measured. In the second part mortice views were taken in plantarflexion and dorsiflexion before and after the placement of syndesmosis screw in theatre. The intermalleolar distance was then measured. Results. In both parts of the study we found the change in intermalleolar distance between the positions of plantarflexion and dorsiflexion was not more than 0.9 mm. This change is significantly less than the calculated difference between the anterior and posterior talar body width of 3-5 mm. Conclusion. This study shows that the width of ankle mortice is independent of the position of the talus occupying it and hence dorsiflexion of the ankle at the time of syndesmosis screw placement is totally unwarranted

Introduction This study aims to improve knee arthroplasty prosthetic alignment by determining if an algorithm based on establishing the most prominent points on the medial and lateral malleolion 3D CT scans can be used to establish the true center of the ankle joint. Methods Axial, coronal and sagittal multi-planar reconstructions were generated on 20 ankles. Two observers independently identified the most prominent medial and lateral malleolar points, in the coronal plane, and the highest talar dome point, in the sagittal plane. Ratios were calculated comparing total intermalleolar distance to distance to medial and lateral malleolus, and the ratio of medial to lateral distance. The distance from the true center of the joint, in the sagittal plane, to the computer calculated center was determined. Statistical analysis using ANOVA, paired t-tests and regression analysis was performed. There were 17 normal ankles, two arthritic ankles, and one previously fractured ankle. Results In the coronal plane there was a strong correlation between the measurements of each observer. The mean intermalleolar distance was 70.2 mm (95% CI 68.3–72.0). The strongest correlation was seen in the ratio of lateral distance to total distance (r=0.728) which was 0.57 in normal ankles (95% CI 0.55–0.58). The ratio for arthritic ankles was 0.48 (95% CI 0.46–0.50) and for the fractured ankle 0.57 (95% CI 0.15–0.99). These were significantly different at the five percent level (p< 0.02). The normal ankle ratio was substantiated by regression analysis. There was a poor correlation between the individual measurements in the sagittal plane (r=0.218). The mean distances from the calculated line to the true center were not statistically different with the true center always lying posterior to the calculated line (4.2 mm (95% CI 2.5–5.9) and 2.8 mm (95% CI 1.7–3.8) posterior. For the combined data this means that the mean distance that the true center of the ankle joint’s from a line joining the medial and lateral malleoli is 3.2 mm (95% CI 2.3–4.0 mm). The data was reproducible with a small standard deviation in each plane. Assuming a 300 mm tibial length, angular error in tibial alignment generated by a computer navigation system is less than one degree in both planes. Conclusions The algorithm presented can give accurate measurements of normal ankle joints in knee navigation surgery

We measured the clinical tibiofemoral (TF) angle and the intercondylar (IC) or intermalleolar (IM) distance in 427 normal European children (212 male and 215 female) aged from 10 to 16 years. In our study, girls had a constant valgus (5.5 degrees) and displayed an IM distance of < 8 cm or an IC distance of < 4 cm. By contrast, boys had a varus evolution (4.4 degrees) during the last two years of growth and displayed an IM distance of < 4 cm or an IC distance of < 5 cm. Values above these for genu varum or genu valgum may require careful follow-up and evaluation