Guided growth may not be the best option for knee valgus deformity in adolescent patients with Morquio-A

Valgus deformity in knees is a common concern in Morquio-A patients, preceding premature arthrosis and pain leading to walking disability and loss of ambulatory status. Treatment alternative is the guided growth, but this is sometimes not applied on time. Due to short height reached on these patients, not all will benefit from guided growth surgery.

The purpose of this study is to describe early results of physeal osteotomy for acute valgus correction in adolescent patients and those almost at height peak to achieve alignment.

We perform the osteotomy in four knees of 10- and 14-year-old patients, fixed with Kirschner wires, and allow early weight bearing. This is compared with one patient who was managed by guided growth.

The average acute correction osteotomy was 39 degrees with intermalleolar distance of 350 and 240 mm. At final follow-up, this measure was reduced to 70 and 20 mm, respectively, with clinical valgus of 4° and 2°. For the patient with guided growth, she was operated at 10.2 years old and 36 months in follow-up; preoperative valgus was 28/24° with intermalleolar distance of 140 mm. At the end of follow-up, this distance was increased to 150 mm with clinical valgus of 18/22°. During this follow-up, none of the patients lost ambulatory status. As a part of multi-organic disease progression, none of the three patients completed the 6-min walking test at final follow-up.

This physeal osteotomy is a feasible and optimal option to achieve acute valgus correction on severe deformity when there is not enough remaining growth on adolescent Morquio-A patients, and may help reduce arthritis progression in adjacent joints.