Purpose of the study: Treatment for tears of the anterior cruciate ligament (ACL) in paediatric patients has been a long-discussed issue because of complications associated with ligament reconstruction in the presence of growth plates. Various fixation materials and their efficiency as well as ACL techniques are still under investigation. The aim of our study was to find an optimal strategy of treating acute intra-articular ACL injury in childhood.
Material and methods: The paediatric patients treated for primary traumatic ACL injury between 2003 and 2013 were retrospectively evaluated. Only patients with a healthy contralateral knee (with no signs of instability or previous injury) and no record of previous ACL repair were included. A total of 78 patients were assessed; there were 39 girls and 39 boys with an average age of 15.4 years (11 - 16). The physical development of the patients was assessed on the Tanner scale, their satisfaction was recorded on the basis of the IKDC subjective knee evaluation form and the Tegner-Lysholm scoring system. The instrumented Lachman test using a rollimeter was performed to assess knee stability at 12 and 24 months of follow-up. In addition, the range of knee motion in comparison with the other side, complications and the re-rupture rate of reconstructed ACLs were recorded. Four patients with open growth plates were operated on using the transepiphyseal technique, the remaining 74 underwent reconstruction by the standard transphyseal method.
Results: The average Tegner-Lysholm scores were 54 (41-62) pre-operatively and 86.1 (74-96) at 24 months post-operatively. The average IKDC score increased from 48 (42-56) points to 91 (73-97) points. The Lachman test was positive in all patients before ACL reconstruction and negative in 96% of them at 12 and 24 months after surgery. The full range of joint motion was restored after ACL surgery, with minimal motion restriction in flexion and extension, in 70 (89.7%) patients. Motion restriction by 15° or less in flexion and 5° or less in extension was recorded in seven (9%) patients and a significant restriction in extension exceeding 10° was found in one (1.3%) patient. No differences in results were found between the two scoring systems. Five patients (6.4 %) sustained a re-tear in the reconstructed ACL due to a trauma. Non-traumatic subjective instability after the primary repair was not recorded. Revision ACL surgery was carried out due to fixation materials protruding from the bone surface in two patients and because of a Cyclops lesion with extension deficit in one patient. No development of deformity or instability was observed at 24 months in the patients in whom the transepiphyseal technique was used. DISCUSSION In the current literature ACL reconstruction by the transphyseal technique has been described in patients older than 15 years of age but no optimal age has been suggested. Animal experiments have shown that tunnels taking up more that 7-9% of the growth plate surface can result in growth restriction or angular deformity. ACL reconstruction in patients with distinct bone immaturity carries a high risk. The effect of growth on the biomechanical properties of a graft and a long-term consequence of surgical intervention in the growth plate is not yet understood.
Conslusions: Although indications for surgical ACL repair and its timing are bound to be different in each patient, we consider the age of over 15 years to be ideal for ACL reconstruction. In patients younger than 15 years, the necessity of surgical treatment is questionable and conservative therapy can give good outcomes. No adverse effect of an applied graft on the post-operative results was demonstrated. The features of an immature skeleton are specific and complicated therefore, in our view, the relevant health care for paediatric patients should be concentrated into specialised institutions.