Purpose. This study aims to report the radiological corrections achieved and complication profile of Peri-Acetabular Osteotomy (PAO) undertaken through the minimally invasive approach. Method. 106 PAOs were performed in 103 patients, by senior author, using a minimally invasive approach from 2007 to 2015. Pre- and post-operative radiographs were reviewed and the degree of acetabular re-orientation was analysed. Case notes were examined retrospectively to identify haemoglobin levels and complications across two sites. Results. 73 female and 30 male patients underwent PAO procedures at a mean age of 25 years (9 – 54 years). Follow-up ranged from 23 to 80 months. 26 patients had concurrent proximal femoral osteotomies. Pre-operatively the average centre edge angle measured −1.6° with the vertical centre edge angle reading −0.2°. Post-operative radiographs confirmed correction of these values to 30° and 25.1° respectively. Sharp's angle also improved from a mean value of 49.5° to 33.3°. Review of the Tönnis angle showed correction from an average of 24.1° to 6.9°. The average drop in haemoglobin was calculated as 39 g/L with around 50 % of the patients requiring a peri-operative blood transfusion. The mean preoperative modified Harris Hip Score was 65.6 (Standard deviation σ=11.6) and the same at follow-up was 84.1(σ=11.5). Our outcome scores were comparable with recent PAO series including that of Gray et al. 10 patients reported lateral cutaneous nerve hypoesthesia and 9 had problematic screws. 2 patients underwent washouts as treatment for haematoma and infection. 4 patients had delayed union of the pubic osteotomy and a further 8 patients had asymptomatic osteotomy non-union. One posterior column non-union necessitated plating. One painful fibrous union of ischium and 3 inferior pubic rami stress fractures. Conclusion. This study shows that minimally invasive approach has favourable outcomes and that it is feasible to achieve adequate correction with results/complication profile comparable to traditional approach

Aims

We wished to examine the effectiveness of tibial lengthening using a two ring Ilizarov frame in skeletally immature patients. This is a potentially biomechanically unstable construct which risks the loss of axial control.

We treated eight dysplastic acetabula in six skeletally mature patients with Down’s syndrome by a modified Bernese periacetabular osteotomy. The mean age at the time of surgery was 16.5 years (12.8 to 28.5). Mean length of follow-up was five years (2 to 10.4).

Pre-operatively the mean (Tönnis) acetabular angle was 28°, the centre-edge angle was −9°, and the extrusion index was 60%; post-operatively they were 3°, 37°, and 17%, respectively. Two patients with post-operative (Tönnis) acetabular angles > 10° developed subluxation post-operatively and required secondary varus derotation femoral osteotomies. Another patient developed a late labral tear which was treated arthroscopically. All eight hips remain clinically stable, and are either asymptomatic or symptomatically improved.

These results suggest that the modified Bernese periacetabular osteotomy can be used successfully in the treatment of acetabular dysplasia in patients with Down’s syndrome.

Osteofibrous dysplasia is an unusual developmental condition of childhood, which almost exclusively affects the tibia. It is thought to follow a slowly progressive course and to stabilise after skeletal maturity. The possible link with adamantinoma is controversial and some authors believe that they are part of one histological process.

We retrospectively reviewed 16 patients who were diagnosed as having osteofibrous dysplasia initially or on the final histological examination. Their management was diverse, depending on the severity of symptoms and the extent of the lesion. Definitive (extraperiosteal) surgery was localised ‘shark-bite’ excision for small lesions in five patients. Extensive lesions were treated by segmental excision and fibular autograft in six patients, external fixation and bone transport in four and proximal tibial replacement in one. One patient who had a fibular autograft required further excision and bone transport for recurrence. Six initially underwent curettage and all had recurrence. There were no recurrences after localised extraperiosteal excision or bone transport. There were three confirmed cases of adamantinoma.

The relevant literature is reviewed. We recommend extraperiosteal excision in all cases of osteofibrous dysplasia, with segmental excision and reconstruction in more extensive lesions.

Extensive limb lengthening may be indicated in achondroplastic patients who wish to achieve a height within the normal range for their population. However, increasing the magnitude of lengthening is associated with further complications particularly adjacent joint stiffness and fractures. We studied the relationship between the magnitude of femoral lengthening and callus pattern, adjacent joint stiffness and fracture of the regenerate bone in 40 femoral lengthenings in 20 achondroplastic patients. They were divided into two groups; group A had lengthening of less than 50% and group B of more than 50% of their initial femoral length. The patterns of radiological callus formation were classified according to shape, type and features. The incidence of callus features, knee stiffness and regenerate bone fracture were analysed in the two groups. Group B was associated with an increased incidence of concave, lateral and central callus shapes, adjacent joint and stiffness and fracture. Statistically, the incidence of stiffness in adjacent joints and regenerate bone fracture was significantly associated with the magnitude of lengthening.

We suggest that careful radiological assessment of the patterns of callus formation is a useful method for the evaluation and monitoring of regenerate bone.