»» Hi. My name is Shannon. I'm going to talk to you today about the anterior displacement of tibial spine fractures and whether or not anatomic reduction matters. I'd like to thank the tibial spine reg and Dr. Yen for allowing me to present this research. I have no relevant disclosures to share with you today. So tibial spine fractures represent an avulsion injury of the ACL from its insertion on the tibia. These injuries result in increased laxity of the ACL and if they're treated without the ACL in mind, patients can heal with loose ACLs and that drastically decreases their knee stability and increases their risk for ACL tears of the injured knee. Measurements of tibial spine fractures are measured in millimeters and they're taken from the anterior tibial plateau to the superior aspect of the fragment. This measurement represents the anterior lip displacement or as we'll refer to it as the ALD. So the goals of operative treatment are to reduce the fragment as anatomically as possible as well as to retain tension to the ACL. But despite these efforts, anatomic reduction is not always achieved. So historically surgeons focused more on the reduction of the fragment and this left patients with ACL laxity and it was commonly understood that the poor reduction of the fragment could hinder the range of motion of the knee. The modern technique incorporates more thought about restoring ACL tension and that is in hopes to increase knee stability for the patients. On the left we have preoperative x-rays and on the right are post-op and as you can see the surgeon nicely reduced this fragment and there's very little displacement remaining. Here's an example of a not so good reduction and we're looking at the post-op x-rays on the right. We can see the fragment still has significant anterior and posterior displacement even after reduction. Our study focused on this residual displacement to see if the anterior portion of the tibial spine affected that range of motion or the laxity in post-operative and non-operatively treated tibial spine fracture patients. We did a medical record review at 10 institutions. Our inclusion criteria was patients age 0 through 25 and if they presented to a clinic with a tibial spine fracture between January 1, 2000 and January 31, 2019. We reviewed radiographic imaging data and measured and collected anterior lip displacement. We also reviewed clinical data and reviewed range of motion and laxity. The complications we focused on were arthrofibrosis and ACL tears of the injured knee. So we grouped the patient residual anterior lip displacements into four categories, excellent being 0 to 1 millimeter, good being 1 to 3 millimeters, fair being 3 to 5 millimeters and poor being greater than 5 millimeters. And we took this from the patient's initial pretreatment measurement to their final follow-up visit in clinic. For the entire cohort, the median ALD treatment prior to treatment was 6.1 millimeters and decreased to 0.7 millimeters after treatment and this number was statistically significant. Looking at the clinical lax, we found there was no difference across four groups. And this tells us we really don't need a perfect reduction to get that same degree of laxity in the knee. And for ACL preconstructions for tears of the injured knee, it was not statistically significant across the groups. For range of motion, like I previously discussed, it was believed that if the anterior lip remains elevated that the patient is going to have a difficult time reaching full extension. If we look at the median across these groups, the difference was only 10 degrees when we get to the group that received the poor reduction. But we also see that patients who did receive an excellent and good reduction still had to be brought back into the operating room for manipulation under anesthesia or laces of adhesions to regain that full range of motion. In the operative group, we broke down range of motion into extension and flexure contractures with the goal of visualizing where these patients were struggling in achieving their full range of motion. Essentially, the incidence of flexion contractures was no more than 10 degrees, which some would argue is clinically significant. And this is the same across all four groups. Looking at extension contracture, it was all very similar across all four groups. So what we determined from this data is that residual anterior lip displacement does not influence laxity, extension or flexion contracture, or reoperation rates. Here we have two postoperative x-rays. On the left we have a patient who received a good reduction with a screw fixation. On the right we have a patient who received a not-so-good reduction with a suture fixation. So as you can see, the screw is sticking up the same amount as the fracture is on the right knee. And that's just an important reminder that even though the residual anterior lip displacement didn't influence these outcomes, we can continue to look in the future research at different factors. So to conclude, reduction is definitely important. But the surgeons don't have to stress about this in the OR about attaining anatomic position to influence these outcomes. Thank you.

anterior displacement

tibial spine fractures

anatomic reduction

ACL avulsion

knee stability