Epidemiology of internal derangement of knee

Aim: In patients with traumatic knee injury, to study the spectrum of structural injury, as visualised on MRI.
Materials and Methods: 48 patients of traumatic knee injury from a military training centre who reported to a peripheral hospital with traumatic joint hemarthrosis, underwent MRI of the injured knee within 1 week of injury. Structural injury as visualised on MRI in relation to age, sex and activity at injury was studied.
Results: The majority of injuries (43.75%) occurred during training activities. ACL tear was the most common structural injury (58.33%) with a similar number of medial meniscus injury (58.33%). Isolated ACL injury was rare (4.16%) and was mostly associated Medial Meniscus injury (37.5%). The age group of 30-40 years is most commonly affected (45.83%).Male sex is more commonly affected (97.91%).
Conclusion: ACL injury is the commonest Internal derangement of knee followed closely by Medial meniscus injury. Isolated ACL tear is rare and is most commonly associated with medial meniscus injury. Male sex and the age group of 30-40 years is most commonly affected.
Limitations: This study has certain limitations. The sample size is small and may not be fully representative of the general population since the patients who reported to the health care centre involved mostly young adult males undergoing rigorous physical training. There was a single female patient who was included in this study who sustained a Road traffic accident.