Aims: To assess the value of hip arthrography in planning definitive treatment for children with DDH and Perthes’ disease.

Background: It is sometimes unclear whether children with DDH and Perthes’ disease need an operation. Surgeons are guided by the clinical symptoms and signs together with the radiographic appearances of the affected hip. In our Unit children on whom an operation is considered undergo an examination under anaesthetic (EUA) and a hip arthrogram. This prospective study was developed to assess whether treatment was modified by the arthrogram.

Methods: All patients who underwent an EUA and hip arthrogram for DDH or Perthes’ disease over a 10 month period were entered into this prospective study. Prior to arthrography a Consultant Children’s Orthopaedic Surgeon formulated a treatment plan. A standard arthrogram was performed which included anteroposterior, frog lateral, Von Rosen and oblique views. Traction axial loading views were taken to assess stability. Following EUA and arthrogram the Consultant Surgeon formulated a definitive treatment plan. Three Children’s Consultants were then invited subsequently to review the preoperative and arthrographic appearances blindly to monitor reproducibility. Twenty-one patients with DDH and 19 with Perthes’ disease were entered into the study.

Results: In the DDH group of patients the treatment plan was modified in 12 of the 21 patients as a consequence of the arthrogram. Six of the 19 patients (31.6 %) of the Perthes’ affected patients had their treatment modified. When it was felt likely prior to EUA a conservative treatment was indicated. The correlation of intra-observer Consultant agreement was high but inter-observer Consultant agreement was moderate only. In both groups of patients the range of hip motion was significantly greater under anaesthesia.

Conclusion: Static and dynamic arthrography helps decision making in patients with DDH and Perthes’ disease.

Introduction and Aims: The effects of injury to the posterior cruciate ligament (PCL) and posterior-lateral corner (PLC) on physical function are not as well documented compared to the more common injury to the anterior cruciate ligament. This study aimed at improving our understanding of PCL/PLC injury through gait analysis and electromyographic (EMG) testing.

Method: We studied 19 patients, average age 30 years (20–55) with clinically and radiologically confirmed PCL/PLC deficiency in isolation. Ninety percent of patients complained of instability when performing the activities of daily living and all complained of pain. All patients were assessed using the Lysholm and Gillquist functional knee score as well as gait analysis, including Kinematics, Kinetics and EMG of the quadriceps, hamstrings and gastrocnemius muscles. Findings were compared to our normal database. The mean Lysholm score was 51/100 (24–90). Those with a Lysholm greater than 50 were designated as ‘copers’.

Results: There were 12 ‘non-copers’ and seven ‘copers’. Fifty percent of patients demonstrated a varus thrust through stance. Forty-two percent of patients demonstrated hyperextension of the knee through stance. Sixty-three percent of patients demonstrated premature and prolonged hamstring activity. Thirty-seven percent of patients had premature activity of the gastrocnemius muscle in stance. Fifty-seven percent of the ‘copers’ demonstrated premature and prolonged hamstring activity through the gait cycle compared to forty-five percent of ‘non-copers’ (non-significant p=0.25 Fishers Exact Test). Fifty-five of ‘non-copers’ demonstrated premature activity of the gastrocnemius muscle in stance compared to none of the ‘copers’ (significant p=0.025 Fishers Exact Test).

Conclusion: The observed varus thrust may be responsible for the development of medial and patellofemoral compartment osteoarthritis, a recognised problem in PCL deficient knees. Hyperextension that occurs dynamically during gait could explain failure of PCL/PLC reconstruction over time. The observed abnormal hamstrings activity is unlikely to be a compensatory mechanism.

Introduction: The purpose of this study was to quantify changes in lower limb muscle strength in children with spastic diplegic cerebral palsy 6 months after multi-level orthopaedic surgery.

Method: A consecutive sample of 20 children ( 10 girls and 10 boys, mean age 10.6) with spastic diplegia was studied prospectively. All participants had soft-tissue and bony surgical procedures performed as part of their clinical management. Physiotherapy treatment commenced following surgery. Lower limb muscle strength, pre and 6 months post-surgery, was measured, in addition to routine gait and function assessment. Maximum voluntary isometric strength of 5 muscle groups was measured bilaterally using a digital dynamometer. Paired-samples t-tests were performed.

Results: There was a marked deterioration of muscle strength (p < 0.05) in all muscle groups. Medial hamstrings and hip flexors showed the greatest decline with an average decrease of 54% and 41% respectively. Analysis of gait parameters showed a significant improvement in kinematics (p< 0.05) but a decrease in walking velocity and cadence. Motor function decreased significantly (p< 0.05). There was reduced motor power in 18 of the 20 at 6 months.

Discussion: Our results quantified objectively the magnitude of strength changes after multi-level surgery and show that weakness may be greater and persist longer than expected. This information will be useful for planning treatment after multi-level surgery and is part of a randomised trial investigating strength training. In general there is a decrease in power but an improvement in gait.

Introduction: Traditionally, the degree of correction for derotational femoral osteotomies in cerebral palsy has been based on clinical or radiographic measures. Recently, three dimensional gait analysis has been used to plan and evaluate orthopaedic surgery. Our aim was to assess the outcome of derotation osteotomies, where the degree of rotation at surgery was guided by transverse plane kinematics (aiming at reducing peak hip rotations to normal limits).

Method: Pre and post-operative gait analyses were reviewed in a group of these patients (16 legs) and compared with a similar group of 8 patients (16 legs) who had soft tissue procedures only.

Results: Improvement following derotation osteotomy occurred in all but one case; 11/16 osteotomies resulted in peak internal rotation within one standard deviation (SD) of peak normal internal rotation (normal range −6° to +11°), the other 4 were within 1.4 SDs.

Discussion: Objective improvement in hip rotation during gait was measured in 15/16 subjects undergoing dero-tation osteotomy based on gait analysis. There was no rotational change overall in patients who had soft tissue procedures only. Average dynamic correction of internal rotation during gait was slightly less than intra-operative correction, possibly due to tensioning of spastic muscles.