Summary

Primary tunnel dilatation is a intra-operative complication in ACL reconstruction which most commonly occurs in the tibial tunnel during graft fixation with interference screw. This complication can lead to graft slippage which in turn can lead to failure.

Abstract

Aim

To study the occurance of primary tunnel dilatation in tibia as an intra-operative complication during Anterior cruciate ligament reconstruction.

Background

ACL reconstruction is one of the commonly performed arthroscopy surgeries. Primary tunnel dilatation can be described as widening of bone tunnel intra-operatively while fixing the graft with interference screws. This complication is more common in tibia and rarely happens in femur owing to the compactness of bone in femur. This complication is not well understood nor discussed in arthroscopy literature.

Study: Prospective study in a tertiary level university teaching hospital from June 2008- June2017.

Materials & Methods:1543 patients who underwent Arthroscopic ACL reconstructions were included in the study. All patients were operated by the same surgical team. ACL reconstructions were either performed using bone patella tendon bone, hamstrings & central quadriceps tendon autografts depending upon indications. ACL graft at the tibial tunnel was fixed using interference screw fixation in all the cases. Fixation of the graft in the femoral tunnel was either by extra-cortical suspensory fixation or by interference screw. All tibial tunnels were drilled using impaction reamers. Primary tunnel dilatation at the time of tibial interference screw fixation was noted when the author felt decreased implant fixation stiffness.

Results

Out of the 1543 patients, there were 85.98% males & 14.01% females. 56.19% belonged to the age group of 18-30years, 28.48% belonged to the age group of 30-40 years, 15.31% were more than 40 years of age. The total number of acute ACL injuries were 109 (7.1%), chronic cases were 737 (48.04%) and the rest 688 were sub-acute which constituted 44.86%. Primary tunnel dilatation was observed in 129 patients (8.37%). Further analysis revealed increased incidence of primary tunnel dilatation in chronic cases 73 patients, followed by sub-acute cases 37 patients and 19 patients in acute cases, with increase in incidence in elderly age group.

Conclusion

Primary tunnel dilatation is a unrecognised complication in ACL reconstruction. Bone quality should be given due importance while performing such surgeries. ACL reconstruction performed in acute stages can avoid this complication.