ACL Rupture in Skeletally immature (children)

Diagnosis of Anterior Cruciate Ligament (ACL) Rupture in the skeletally immature can be more difficult. It is found that there is poorer correlation between history, clinical examination, and arthroscopic findings.

Imaging is best by MRI scan, however this technique is less sensitive and specific than in adults because of less experience, variations in developmental anatomy, smaller anatomic structures, a higher rate of partial rupture and a higher rate of false-positive meniscal tears because of the greater vascularity of the paediatric meniscus could be miss diagnosed as tears.

Pathology – partial tears are more common than in adults. They can be up to 60% in some studies. Meniscal tears are less common than in adults (though still very common).

Around 50% of children with a haemarthrosis (blood collection in the joint) will have an ACL injury.

Natural history is manifested by a high rate of symptomatic instability and secondary injury such as meniscal and chondral (articular cartilage).

Treatment could be non-operative, which includes functional bracing, a comprehensive rehabilitation program and avoidance of sport activities that may expose the patient to meniscal and cartilage injuries. Such activities include any twisting and pivoting of the knee joint. The aim is to delay surgery until approaching skeletal maturity.

The latest evidence based medicine supports a surgical treatment in children similar to adults, with some modifications. The main concern about surgery is damage to the growing bone of the lower femur and upper tibia.

Operative treatment options include intra-articular reconstruction, which could be done in one of three different techniques.

Physeal sparing where the whole reconstruction process is done outside the growth plate so less chance of growth arrest.

Partial transphyseal techniques keep the tibial attachment of either hamstrings, or PT, and have them run either through the tibia (partial transphyseal) or over the front of the tibia (physeal sparing), to insert in an over-the-top position on the femur. This technique may need revision to adult technique after reaching skeletal maturity.

Complete transphyseal (adult technique) with some modifications including using smaller drill tunnel, more vertical tunnel, clearing the tunnel from any bony debris and avoiding using a bone block across the growth plate.

The other option is using extra-articular technique such as Ilio-tibial band or Patellar tendon tenodesis. This technique is not so commonly used since the results are poor; the grafts are non-anatomic and non-isometric.

For further information, refer to the adult ACL reconstruction.[i1] .