Reduction in primary genu recurvatum gait after aponeurotic calf muscle lengthening during multilevel surgery.
Loosening tight calf muscles during one surgery cuts knee hyperextension by about 10 degrees in most kids with CP.
01Research in Context
What this study did
Doctors looked at kids with cerebral palsy who walked with knees bent too far back. This is called genu recurvatum.
They cut the tight calf muscle during one big surgery. Then they watched how the kids walked for 14 months.
What they found
Most kids gained 10 degrees more ankle bend and lost 10 degrees of knee hyperextension. That happened in 77 out of every 100 legs.
Walking looked smoother and the knee no longer snapped backward after heel strike.
How this fits with other research
Whitehouse et al. (2014) first showed that tight ankles and knee hyperextension travel together. The new study proves fixing the tight ankle really does fix the knee.
Eussen et al. (2016) extended the idea. They split kids into early and late hyperextension groups. Early group gained 11 degrees, late group only 6. So timing matters when you pick patients for surgery.
van Drongelen et al. (2013) used the same one-day multilevel surgery in twins. They also saw better gait, but they cared about trunk and genetics, not knees. Same surgery, different focus.
Why it matters
If a child with CP shows a knee that snaps backward right after the heel hits the floor, check ankle dorsiflexion first. Tight calves are likely the driver. Share these numbers with the orthopedic team to support a calf-lengthening decision. After surgery, use video gait clips to show families the 10-degree change in knee angle; visual feedback keeps everyone motivated.
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Join Free →Screen ankle dorsiflexion with a simple knee-to-wall test; if less than 10 cm, flag for medical consult.
02At a glance
03Original abstract
Knee hyperextension (genu recurvatum, GR) is often seen in children with bilateral spastic cerebral palsy (CP). Primary GR appears essential without previous treatment. As equinus deformity is suspected to be one of the main factors evoking primary GR, the purpose of this study was to determine whether lengthening the calf muscles to decrease equinus would decrease coexisting GR in children with bilateral spastic CP. In a retrospective study, 19 CP patients with primary GR (mean age: 9.4 years, 13 male, 6 female, 26 involved limbs) in whom an aponeurotic calf muscle lengthening procedure was performed during single-event multilevel surgery were included and investigated using three-dimensional gait analysis before and at a mean follow-up of 14 months after the procedure according to a standardized protocol. After calf muscle lengthening, a significant improvement in ankle dorsiflexion (9.5°) and a significant reduction (10.5°) in knee hyperextension (p<0.001) were found during mid-stance of the gait cycle. Six limbs (23%) showed no improvement concerning knee hyperextension and were designated as nonresponders. In these patients no significant improvement in ankle dorsiflexion was found after surgery either. Improvement in ankle dorsiflexion and reduction in knee hyperextension in stance phase correlated significantly (r=0.46; p=0.019). These findings indicate that equinus deformity is a Major underlying factor in Primary GR and that calf muscle lengthening can effectively reduce GR in patients with CP.
Research in developmental disabilities, 2013 · doi:10.1016/j.ridd.2013.08.019