O. Lawani1, S. Agboola2 1Cedarcrest Hospital, Children’s Orthopaedic Unit, Department Of Paediatric Orthopaedics, Abuja, FEDERAL CAPITAL TERRITORY, Nigeria 2Cedarcrest Hospitals, Department Of Radiology, Abuja, FEDERAL CAPITAL TERRITORY, Nigeria 3University of Abuja Teaching Hospital, Division Of Paediatric Surgery, Abuja, FEDERAL CAPITAL TERRITORY, Nigeria
Introduction: This abstract describes radiologic measures we have adopted for infantile Blount’s disease and our treatment algorithm based on this. It also discusses our early results.
Infantile Blount’s disease is fairly common amongst persons of African descent. Current radiologic assessment techniques include the landmark works of Langenskiold, Drennan and Lamont. A high risk of recurrence following surgery is documented despite treatment based on correcting the mechanical axis to valgus. This is often due to under – estimation of the severity of disease at presentation.
Methods:
A review of 8 knees was conducted in children less than 12 years with infantile onset of Blount’s treated in our unit. All the children were assessed using plain supine films of the knees and CT scans of the physis. Goniometric readings were obtained for the following parameters:
Distal femur valgus (DFV) – target value < 10 degrees
Proximal tibia Metaphyseal – Diaphyseal angle (MDA) for open physes / Centre of rotational abnormality (CORA) for closed physes
Proximal tibia medial joint line depression (MJLD) – target value < 30 degrees
Presence or absence of physeal bar (PB) / physeal closure
Langeskiold grading
Our algorithm prescribes specific surgery to correct the MJLD and MDA to target and resect physeal bars as required. All the children had a standardised bracing regimen for the first 12 – 16 weeks postoperative. Supervised weightbearing was then started. Pre – and post – operative measurements for each limb are documented in tabular form. Analysis was with simple measures of dispersion were used to summarise the data.
Results:
Goniometric measurement of the five radiologic parameters was done. Surgery was conducted to correct abnormal values and restore a valgus mechanical axis of the affected lower limb sufficient to maintain loading through the lateral tibia plateau during simulated weightbearing. The mean postoperative distal femur valgus (DFV) was 7.9 degrees. Mean correction achieved in medial joint line depression (MJLD) was 21.3 degrees. Mean postoperative metaphyseal – diaphyseal valgus angle achieved was 19.5 degrees. Mean duration of follow – up was 1 year.
Conclusion:
Combining radiologic measures with targets has helped to streamline our surgical treatment for infantile Blount’s disease and reduce the risk of recurrence due to under – correction.