Findings detail efficacy of anterior distal femoral hemiepiphysiodesis for arthrogrypotic knee flexion contractures

Although anterior distal femoral hemiepiphysiodesis alone was effective for knee flexion contractures of 25° or less in growing children with arthrogryposis and was relatively reliable with the addition of a posterior release for patients with contractures of 40° or less, researchers found half of knees with contractures of greater than 40° were adequately corrected.

The research was presented at the Limb Lengthening and Reconstruction Society Annual Scientific Meeting.

“For contractures less than 40°, the growth guidance techniques are a reliable way of getting knee flexion contractures resolved in children with arthrogryposis,” Harold J.P. van Bosse, MD, from the Shriners Hospital for Children in Philadelphia, told Healio.com/Orthopedics. “[In] contractures of 25°, we recommend a posterior knee release along with the application of the hemiepiphysiodesis plates.”

van Bosse and colleagues reviewed the cases of 37 consecutive pediatric patients (60 knees) with arthrogryposis and knee flexion contractures treated with anterior distal femoral hemiepiphysiodesis. At surgery, the mean age was 6.9 years. The mean follow-up was 3.2 years. Investigators noted posterior release was needed in 48 knees at the time of surgery. Patients were treated with a knee-ankle-foot orthosis in full extension at night during correction and after plate removal.

Preoepratively, the mean knee flexion contracture was 35°. By the time the plates were removed, it improved by 6°. The epiphysiodesis plates, on average, were removed 19 months after implantation. The average correction rate was 6° per 100 days. Knees that did not have a posterior release and had contractures of 25° or less corrected well. With the addition of a posterior release, knees with contractures of 30° to 40° corrected well. However, investigators found 50% of knees with contractures of greater than 40° were corrected to 10° or less. The mean total arc of motion preoperatively and at the follow-up was 70° and 65°, respectively.

The mean contracture was 16° at latest follow-up, and all knees were ligamentously stable. However, at 38 months after plate removal, five patients required repeat hemiepiphysiodesis for contracture recurrence. Seven patients who were initially nonambulatory became ambulatory after their procedure and 10 patients who ambulated with a walker became independent walkers after their procedure.

“We are trying to find a more efficient way of putting the plate in that is also less uncormfortable for patients,” he said. “[The] plates are kind of in the front of knee, so near the side of the knee cap, and for that reason it can cause irritation of the knee. So, we are trying to find a way that we can lessen that irritation across the knee.” – by Monica Jaramillo

Reference:

van Bosse HJP, et al. Correction of mild to moderate arthrogrypotic knee flexion contractures with guided growth. Presented at: Limb Lengthening and Reconstruction Society Annual Scientific Meeting; July 13-14, 2018; San Francisco.

Disclosure: van Bosse reports no relevant financial disclosures.