Part 5: Mid-substance ACL Injury - case example

Interview with the mother...

Mid-substance ACL laxity

In this Part we will briefly outline the management of a young boy with mid-substance image of his ACL following a ski injury. In contrast to the girl presented in Part 4, this procedure 'all-epiphyseal', again using fluoroscopic imaging to follow the drill, and in this case to ensure that on both femur and tibia the drill holes did not go through the growth plates.

As with the girl in Part 4, a FibreLink tape was used as a temporary 'internal brace' and then removed after some months.

Patient: 'Sh'
History

At the age of 6 this young patient had a skiing accident. He was in ski school, so the parents did not actually see the injury but the child explained that the ski binding did not release, and the torque of the ski severely twisted his left knee.

On fetching him, the mother was sure that he had torn his ACL, based upon her own experience as she had previously suffered an ACL tear herself. What is of interest is that by the time he went for MRI imaging two weeks later he was walking normally, but the MRI confirmed that the ACL was indeed torn.

After discussion with several clinicians, he was referred to Professor Adrian Wilson, who decided to repair the ligament and use an internal brace until it healed. He decided on an 'all-epiphyseal' approach.

Examination-under-anaesthesia and Surgery

Examination under anaesthesia confirmed that there was excessive antero-posterior laxity and increased pivot shift, confirming the damage to the ACL.

The surgeon continued to surgery, preparing to do an arthroscopy to assess the damage, after which is was decided to do a repair - all-epiphyseal​ - and to brace the repair with FibreTape.

The arrow points to the 2.4 mm drill within the epiphysis on the femur, that is below the growth plate of the femur. 

Similarly the tibial drill hole was kept within the epiphysis on the tibia (see arrow), that is above the growth plate.

One-year Follow-up

His toes are not quite level here in the right hand picture, giving the appearance of the left being shorter, but long leg X-rays confirmed that there was no shortening.

At one year he reported a normal knee with no subjective symptoms.  He wanted to play football but his mother was worried about this.

Clinical examination was normal, with negative Lachman, pivot shift and anterior drawer tests.​ There was no growth disturbance evident on long leg X-ray. Range-of-motion was -5 to +145 degrees. Scoring tests revealed a KOOS of 100, a Lysholm of 100 and a Tegner of 4.

The Lachmann test at 30 degrees & the pivot shift test assessed with a KIRA demonstrated less than 2 mm side-to-side difference​.

Commentary

Paediatric ACL injury is traditionally perceived as relatively uncommon. However, it is increasingly common in competitive sports, accounting for 0.5-3% of all ACL injuries. This may be because of:

  • increased awareness
  • improved imaging
  • greater demands on athletes at an earlier age
Additional Resources (Click to view)

Internal Bracing Reinforcement

FAQ

Here are answers to some frequently asked questions:

What is internal bracing?

Don't you get synovitis from the tape?

What is FibreTape?

What is a FibreLink suture?

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