Posteror cortex violation unrecognized during LCA reconstructive surgery

Abstract

One of the most important technical demands in ACL surgery is good fixation of the graft. Integrity of the posterior femoral cortex is necessary for Interference screws fixation. The femoral tunnel, placed as posterior as possible, is also mandatory for good graft position and potentially leads to violation of the cortex. The divergence between screw and tunnel could result in perforation of the posterior wall. Without intraoperative x-ray it is difficult to be sure that position of the screw is correct, even with good graft tension. Still, the problem exists with absorbable screws. The aim of the study is to show results of 6 patients with this complication treated without revision of the femoral fixation with mean follow up of 1.5 year. Potential pitfall in ACL reconstruction is posterior cortex breakout and loss of fixation. If it is recognized during surgery changing the type of fixation can solve the problem, but if not, in the early phase of rehabilitation and weight bear, graft failure is feasible. The tibia tunnel angle and length, the footprint of femoral tunnel reamer and hyper flexion of the knee during screw insertion are methods for preventing the breakout of the posterior wall and screw-tunnel divergence. Modification of the early postoperative treatment and less aggressive rehabilitation protocol reduced the need for revision surgery. Even with best surgical technique, skill and experience this complication is possible to occur.

Length of the femoral tunnel in anatomic ACL reconstruction: comparison of three techniques

“…When drilling the femoral tunnel during anatomic reconstruction of the ACL, the surgeon is faced with at least two problems: adequate length of the tunnel and perforation of the posterior femoral cortex [9, 19]. These two issues are at the opposite ends of the lever called the selection of the femoral graft insertion site.…”

“…Perforation of the posterior femoral cortex during tunnel drilling not only increases the duration of the procedure, but also prevents fixation and leads to a new, most frequently non‐anatomic, position of the femoral graft fixation. This type of complication is not very frequent, but it does occur in a certain number of cases [9].…”

No difference in initial fixation or 1-year outcomes with outside in metallic or bioabsorbable interference femoral screws in rectangular tunnel bone-patellar tendon-bone graft for anterior cruciate ligament reconstruction

“…Regarding femoral fixation with IFSs, posterior wall breakage was reported to lead to poor postoperative outcomes unless it was recognised during surgery and another fixation method was performed 12. Although surgeons can confirm the state of the posterior wall by arthroscopically probing and viewing it before passing the graft, it is difficult to evaluate the condition of the posterior wall after IFS insertion.…”

“…Because posterior wall breakage was reported to be associated with poor postoperative outcomes, unless it was recognised during surgery and another fixation method was performed,12 the security of tunnel placement posterior to the ridge with IFS fixation should be investigated. To examine initial fixation failure during surgery, we developed and performed a ‘tensioning trial’ during each operation.…”

The influence of the position of the medial portal and of lower leg flexion on the length of the femoral tunnel in anatomic anterior cruciate ligament reconstruction: A cadaveric study

“…The key to successful anterior cruciate ligament (ACL) reconstruction lies in the proper positioning of the femoral tunnel within the anatomical footprint and in providing for an adequate length of this tunnel without perforation to the lateral cortex. Surgically speaking, it is necessary to choose the place of anatomic insertion on the medial aspect of the lateral condyle, and then it is necessary to drill a tunnel of adequate length across that spot without compromising the integrity of the posterior femoral cortex 1 . By decreasing the angle between the reamer and the medial aspect of the lateral condyle the length of the tunnel is increased, but the position of the tunnel is brought closer to the posterior cortex.…”