Paediatric intrasubstance posterior cruciate ligament rupture.

The authors present the case of a 4-year-old boy who sustained an intrasubstance posterior cruciate ligament (PCL) tear whist trampolining. He was managed non-operatively with return to full function by 8 months. A high index of suspicion is required when assessing paediatric hyperflexion/extension injuries at the knee as ligamentous injury may occur without osteochondral fracture and may be missed on routine radiographs. Early MRI can identify such injuries in addition to osteochondral avulsions which are often amenable to acute internal fixation. In the case of paediatric intrasubstance PCL tears, it appears that non-operative management yields a good functional outcome in the short term in the skeletally immature.