An 11 year old child with an unstable knee as a result of rupture of the anterior cruciate ligament and which is frequently giving way in spite of attempts to either brace the knee or modify activity, is a worrying problem. The correct surgical treatment is still controversial. The two questions which need to be asked are firstly is it safe to continue without reconstruction of the anterior cruciate ligament and secondly how should it be reconstructed?
In this paper the authors state that this is a common injury. It is still relatively unusual but does seem to be becoming more common. In recent years the trend has been very much towards reconstruction of the anterior cruciate ligament in an unstable knee in a child of this age and surgeons are increasingly faced with having to do it. Adult knee surgeons may be reluctant or may not have the facilities for treating young children and paediatric surgeons may not have the experience with anterior cruciate ligament reconstruction to feel comfortable.
The real question is, however, whether or not a surgeon, either adult or paediatric should use a technique such as this Clocheville Technique with which they are not familiar or use the technique with which they are familiar, which would, of course, be a standard transphyseal technique using hamstrings as used in adults.
The authors have considerable experience using their Clocheville technique for reconstructing the anterior cruciate ligament in children. Their results are as good as other techniques and there is no worry of growth plate damage although the other concern of angular deformity by tethering still exists but again their results show that this is theoretical rather than real. The graft is interesting in that it takes a central strip of patellar tendon in continuity with the periosteum overlying the tibial tuberosity and proximally over the front of the patella. In young children this periosteum is thick and can be excised as a strip with the patellar tendon. In the adult, of course, it cannot and this is a concern in older children too. There is always the anxiety that where the graft joins the periosteum is a weak point. Another concern is the fixation of the graft distally. It is placed in a groove on the anterior aspect of the tibial epiphysis and held with sutures. This requires the leg to be immobilised in a plaster cast in slight flexion for 6 weeks post operatively. This is a major disadvantage when other techniques allow early mobilisation. However in these children it does not seem to produce any long term problems. There is also potential concern about the placement of the femoral end of the graft. This is a combination of going over the top of the back of the femur and then through a metaphyseal tunnel where it is held with an interference screw. This paper is short on the technique of how the metaphyseal tunnel is made and where the interference screw is placed. On the post operative radiographs and the MRI it does seem to be placed a very long way away from the femoral epiphysis minimising the risk of damage. However, with over the top techniques there is potential to damage the perichondral ring at the back of the femoral growth plate although again this appears to be only theoretical.
There remains the question of who should do these reconstructions. Surely it is best done by a surgeon who does a lot of anterior cruciate ligament reconstruction using their usual technique which would be a standard transphyseal technique using hamstrings but the point must be made that great care must be taken, drilling very slowly across the growth plates, clearing all bone debris out of the tunnels and using fixation placed well away from the growth plate. There is evidence that this is safe, even in young children and the outcome is likely to be better than a surgeon doing an unfamiliar procedure just because it is a young child.
Mr David Hunt
106 Harley Street
London W1G 7JE