Background: Midsubstance tears of the anterior
cruciate ligament in skeletally immature patients are increasingly
common and are a challenging problem. The results of nonoperative
treatment are no better in children than they are in adults. Physeal-sparing reconstructive
procedures have yielded poor results. Reconstructive procedures
that are utilized in adults violate the physis, potentially resulting
in growth abnormalities. The objective of this study was to provide
a model for reconstruction of the anterior cruciate ligament in
skeletally immature patients by evaluating the effects of a tensioned
connective-tissue graft placed across the canine physis.
Methods: Twelve ten-week-old beagles underwent reconstruction
of the anterior cruciate ligament consisting of placement of fascia
lata autograft through drill-holes across the femoral and tibial
physes, tensioning of the graft to 80 N, and fixing it with screws
and washers. The contralateral limb served as a control. One dog
was eliminated from the study secondary to a postoperative infection.
Four months postoperatively, the dogs were killed and were inspected
grossly, radiographically, and histologically for any evidence of
growth disturbance.
Results: Significant valgus deformity of the distal
part of the femur (p < 0.001) and significant varus deformity
of the proximal part of the tibia (p = 0.03) developed
in the treated limbs. Neither radiographic nor histologic examination
demonstrated any evidence of physeal bar formation.
Conclusions: Significant growth disturbances occur with excessively
tensioned transphyseal reconstruction of the anterior cruciate ligament
in the canine model. These growth disturbances occur without radiographic
or histologic evidence of physeal bar formation.
Clinical Relevance: This study illustrates the risk
to the physis associated with transphyseal reconstruction of the
anterior cruciate ligament with the use of a tensioned connective-tissue
graft in skeletally immature patients. We do not recommend transphyseal
reconstruction of the anterior cruciate ligament in this patient
population.