Background

The anterior cruciate ligament (ACL) is a band of tough tissue inside the knee that helps stabilise the knee during movement. Rupture of the ACL is a common injury during some sporting activities, such as football and skiing. Anterior cruciate ligament injuries are often treated surgically. This usually involves keyhole (arthroscopic) ACL reconstruction, where the torn ACL is replaced by a piece of tendon (graft). The graft is usually extracted from another place near the patient’s affected knee. In ACL reconstruction, bone tunnels are drilled at the knee into the tibia (shin bone) and the femur (thigh bone) to place the ACL graft in almost the same position as the torn ACL.

This review compared two ACL reconstruction techniques: one-incision versus two-incision. The more common two-incision technique involves drilling the femoral (from the thigh bone) tunnel from outside to inside the knee joint with an incision made in the outward aspect of the thigh to reach the bone. In the one-incision technique, there is no (second) incision into the thigh. Instead the graft is fixed to the femur from inside to outside the joint through arthroscopic guidance.

Results of the search

We searched the medical literature databases up to August 2017 for randomised studies comparing one-incision versus two-incision arthroscopic ACL reconstruction techniques. We included five trials involving 320 people undergoing ACL reconstruction with patella tendon grafts. Most of the study participants were in their 20s.

Key results

We found no differences between the two techniques in self reported knee function at around three months, 12 months, or between two and five years. There were no data for quality of life or for the overall number of participants incurring an adverse event. However, we found evidence of little between-group differences in individual adverse events such as infection, knee stiffness, and graft failure. There was evidence of little difference between the two groups in final activity levels or the numbers of participants with normal or nearly normal knee function assessed by clinicians at a year or more after surgery.

Quality of the evidence

All five studies had weaknesses that could seriously affect the reliability of their results. We considered the evidence to be of very low quality, meaning that we are unsure of the results.

Conclusions

The lack of reliable evidence means that we are uncertain whether one-incision arthroscopically assisted ACL techniques are any better (or worse) than two-incision techniques. Further research would help to answer this question but may not be a current priority.