Genu recurvatum is present when the knee is hyperextended, 5 degrees is sufficient. This is present when there is an accident to the knee forcing it backwards or an acquired birth deformity.
Cause
- A defined connective tissue disorder
- Laxity of the knee ligaments
- Instability of the knee joint due to ligaments and injuries to the joint capsule (anterior cruciate ligament)
- Irregular alignment of the femur and tibia
- A deficit in the joints
- A discrepancy in the length of the lower limb
- Certain diseases: cerebral palsy, multiple sclerosis, muscular dystrophy
- Congenital / congenital anomaly
Clinical presentation
- Knee gives way to hyperextension
- Difficulty with endurance activities
- Pinching at the front of the knee
- Anteromedial or posterolateral joint pain
- anteromedial: due to compressive force at the tibiofemoral compartment and is accentuated if a genu varus is present.
- posterolateral: due to tension placed on the posterior structures and is aggravated by an extension force.
The genu recurvatum will cause internal rotation of the femur and tibia. The patella will be deflected inwards and cause premature deterioration of the cartilage on the lateral surface of the patella.
