Occult Intra-articular Knee Injuries in Children With Hemarthrosis

Abstract

Seventy percent of the patients aged 9 to 14 years with traumatic knee hemarthrosis had a serious intra-articular injury that needed specific medical attention. Fifty-six percent of these patients had no visible injury on plain radiographs. Physicians who treat this group of patients should consider MRI to establish the diagnosis when there is no or minimal radiographic findings. The most common serious knee injury was a lateral patellar dislocation. This should be taken into consideration to improve prevention strategies and treatment algorithms in pediatric knee injuries.

The patellofemoral joint: from dysplasia to dislocation

“…A cross-sectional study comparing demographic and anatomical features of 103 skeletally immature patients with lateral patellar dislocation with a matched control group addressed some important points. 24 Overall, 96% of patients with patellar dislocation presented at least one anatomical abnormality among trochlear dysplasia (trochlear depth < 3 mm), abnormal patellar tilt (> 20°), increased TT-TG distance (> 15 mm) or patella alta (Caton-Deshamps Index > 1.2) compared with 42% of the control group. Specifically, 17% of the patellar dislocation group had all four instability factors, 27% had three, 35% had two and only 17% had one abnormality, with trochlear dysplasia the most recurrent one and increased TT-TG never present as an isolated abnormality.…”

Anterior cruciate ligament injuries in children and adolescents

“…However, plain radiographs may miss 56% of serious knee injuries. 16 MRI is accurate at diagnosing ACL tear in children and adolescents, with a reported missed injury rate of only 1.9%. 18 MRI may also aid in preoperative planning of ACL reconstruction.…”

“…This is most commonly caused by patellar dislocation, ACL injury, or tibial spine fracture. 16 If effusion is present with a known injury, MRI is recommended for further evaluation.…”

(i) Knee injuries in children

“…Cruciate ligament injuries Anterior cruciate ligament (ACL) ruptures in children are not an uncommon occurrence, with an incidence of approximately 0.2 per 1000 population per year, 11 and one that causes a management dilemma for many orthopaedic surgeons. Consultation with leading surgeons routinely exposed to such injuries demonstrates widespread variation in management with nearly 60% electing to manage these patients non-operatively, and 26% delaying reconstruction until skeletal maturity.…”