Cruciate repair is an older procedure that is making a comeback - using more modern methods to repair rather than reconstruct the damaged ligament.
The Sherman classification defines where the damage has occurred on the ligament - whether it is torn through the midsubstance of the ligament or whether the ligament has torn off the bone at the upper or lower end. This helps to determine the suitability of the ligament for a repair rather than a reconstruction.
The Location of Anterior Cruciate Ligament Tears: A Prevalence Study Using Magnetic Resonance Imaging. van der List JP, Mintz DN and DiFelice GS. Orthop J Sports Med. 2017 Jun; 5(6): 2325967117709966.
Cruciate ligament repair in children
With the increase in sporting activies of the modern child, and better awareness from the medical fraternity, more and more children are being assessed for torn cruciate ligaments, particularly the anterior cruciate ligament. Teenage girls are at particular risk. After the acute incident the knee may seem to settle down but the child may be reluctant to continue with sporting activities and may start to walk with a peculiar gait.
The particular problem with children is that their growth plates are still open at the ends of the bones, and reconstruction - and even repair - procedures may damage the growth plate and lead to later deformity of the limb. So it is important to identify carefully exactly where the damage has occurred and then assess the bony maturity of the child before planning any procedure, and also to ensure that the parent understands the issues.
High speed injury in the younger child, such as during skiing, may tear the ligament off from its bony attachment on the femur. The midsubstance tear is commoner in the older child or adolescent. Forceful traction in the younger child may lead to an avulsion fracture at the lower end of the ligament, tearing a piece of the tibia bone off with the ligament still intact.
In adult injuries, the tear is usually in the upper or middle part of the ligament, but the fact that in children it is very often where the ligament attaches to bone, sometimes with a bit of the bone still attached allows - in expert hands - the ligament to be re-attached, leaving the ligament intact without need for any graft.
See this useful article on ACL repair in children by Professor Adrian Wilson.
Paediatric ACL repair reinforced with temporary internal bracing. Smith JO, Yasen SK, Palmer HC, Lord BR, Britton EM and Wilson AJ. Knee Surg Sports Traumatol Arthrosc. 2016 Jun;24(6):1845-51. doi: 10.1007/s00167-016-4150-x. Epub 2016 May 3.
Cruciate ligament repair in adults
Adults do not have the same issue with the growth plates that children do, but the greater forces through the adult ligament means that repair is only attempted when the situation is particularly favourable.