Hi again everyone, it's Stephanie Meyer from the University of Colorado. In this talk, I'll be presenting on ischial tuberosity fractures, specifically focusing on the reduction and fixation techniques that we use. This is my one disclosure, which is not really relevant to this talk. Ischial tuberosity fractures will make up somewhere between about 10 and 50% of the pelvic avulsion fractures that you'll see. It occurs in many different sports in adolescence, but typically it's going to be involved with some sort of forced stretch along with an eccentric contraction like sprinting, and there's definitely a male predominant. Most proximally, the semimembranosus tendon is going to insert on the superior and lateral aspect of the ischial tuberosity, and then the semimembranosus, sorry, semitendinosus and biceps femoris are going to come together to form the conjoined tendon, just distal to that. Slightly more distal and medial is the adductor magnus, which really is involved in a lot of these ischial tuberosity fractures, even though we think of them primarily as just hamstring injuries. The group from San Diego has recently published a paper classifying these injuries, basically into type 1 and type 2 fractures, with type 1 involving mostly the lateral aspect of the ischial tuberosity, where the hamstrings themselves are inserting, and type 2 involving the entire apophysis, also including the adductor magnus. They then added a displacement category with displaced or minimally displaced basically being one or less centimeters of displacement. When we think about how to treat these, one of the main things we're thinking about is what the outcome is going to be as far as union or nonunion as well as symptoms. The classification system is helpful because it does show that the type 1 fractures, which occur mainly in younger patients, are slightly less displaced and therefore have a lower rate of nonunion at about 30%, whereas about 75% of them went on to union. The type 2 fractures really only had about a 25% rate of union and a 70% rate of nonunion. Now not all of these are going to be symptomatic, but it definitely makes a difference when you're making a decision on how to treat these patients, whether operatively or nonoperatively. For nonoperative treatment, this is mainly going to be used for minimally displaced fractures, although it's sort of debatable what that number of centimeters of displacement is that is considered minimally displaced, but it's probably somewhere around 1 to 2 centimeters. In both of those studies from the San Diego group, 1 centimeter of displacement of an ischial tuberosity fracture was associated with somewhere between a 25% and 80% chance of a nonunion. Again, not all of them symptomatic, but some of them are, and a 2 centimeter displacement of pelvic abulsion fractures in general had about a 26 times higher chance of a nonunion within that study. If you are headed for operative treatment of one of these fractures, your options are essentially three, screw fixation of the fragment, suture anchor fixation of the fragment, or essentially excision of the fragment, and then a hamstring repair. As far as the operative approach of any of those techniques, you're going to be utilizing either a transverse or longitudinal incision, depending upon how you like to make the incision and your comfort level with each of them. A longitudinal incision is definitely useful when the fragment is very displaced or when you're going to have to be performing a neuralysis of the sciatic nerve over a long portion of the nerve. The next thing you'll encounter after your skin incision is the posterior femoral cutaneous nerve and its branches. And if you can find the main branch of this nerve, this will also lead you down to the sciatic nerve itself. At that point, you'll split the fascia over the gluteus maximus and lift it up in sort of an oblique direction. And then the hamstrings right underneath that, you can follow over to the abulsion itself. At this point, you'll mobilize the avulsion fracture fragment, and I really recommend scraping out a lot of the fissus and definitely getting rid of all of that soft tissue that may be there, scar tissue formation that may be there in that nonunion bed. I think this is really important to prevent a further nonunion or to prevent the fissus from giving you the appearance of a nonunion, kind of similar to a medial epicondyle fracture in the elbow, how that sometimes happens. Scraping the tendon is important because a lot of these do need to be pulled back up to the donor site by several centimeters. And ensuring that the sciatic nerve is not scarred or tethered over to that tendon as you mobilize it is really important, because that could obviously cause a lot of sciatic symptoms if it gets tethered and kinked as you pull the fragment in the tendon proximally. Provisional fixation, if you're going to use screw fixation with either a clamp or a K-wire is helpful. If you're going to be performing suture anchor fixation, this is not as helpful as you're going to be putting the suture anchors in the donor site itself, so you sort of need that to be open. If you're not comfortable performing a sciatic nerve neuralysis, as I am not, I strongly urge you to consider the use of a hand surgeon or a tumor surgeon to perform a co-surgery with you to perform this neuralysis in cases that have chronicity of over really three to four months, even less than that in some cases if it seems like there's a lot of scar formation, or in cases with significant displacement where you're really going to have to be mobilizing that tendon and pulling it proximal by a significant amount of surface area, or if the patient already has sciatic symptoms. Screw fixation of these fragments, in my opinion, is the hardest technique, but it is definitely useful in some cases, especially when you have a larger fragment with a lot of bone surface area. The horizontal trajectory that you need for those screws is more than you would think, and the soft tissue of the buttocks oftentimes prevents you from getting the trajectory that you really need with that drill bit or to put the screws themselves in. Remember that there may look like there's a gap despite some really good purchase that you're feeling with the screws if you did not scrape out all of that fissus or all of the soft tissue. So just be aware of that during the case that it may look different than what it feels like with the screws. This is an example of some post-op images of a healed ischial tuberosity avulsion fragment with some different images and trauma views that I got just showing all the trajectories of those screws. Suture anchor fixation, I think, is a really good technique and something that a lot of us are familiar with due to already doing some proximal hamstring repairs. I think that is a useful technique in cases where there may not be quite as much bone on the bone avulsion fragment as in this case where the fracture fragment was pretty hypertrophied and I felt that I was going to be scraping out a lot of that bone and that I was going to be left with kind of more of a shell of bone and mainly to perform a hamstring repair. This is a 15-year-old male with an injury that was about four months old with pretty significant displacement. And so I felt that those suture anchors were going to be a good way to shuttle and really cinch that fragment down after we scraped out the hypertrophied abnormal bone. The reduction and mobilization and preparation of the bony fragment is the same as screw fixation. We did perform a sciatic nerve neuralysis in this particular case, and with this, I typically use two to three larger double-loaded anchors right into that ischial tuberosity donor site. In this type of case, we will suture these through and also sometimes around the fragment with a Mason-Allen type of stitch to cinch it down and shuttle it down to create good fixation. Lastly, debriding the fragment itself and just performing a primary hamstring repair, I think, is a very viable option in several situations. If you have a very small fragment where you're really not going to be able to get good purchase of a screw or even good purchase of a suture anchor suture through the fragment itself, this is a great option. In an older patient that may not have as good bone-to-bone healing as a young patient, especially if it's a chronic avulsion, this may be a good option. In revision situations where the bone has shown that it is not going to hold a suture anchor or a screw, this is a good option. And also in this particular case here, this was a 20-something year old male that had a very chronic and very hypertrophied fragment. A lot of his symptoms were with sitting, and I did not feel that just reducing this fragment down by those couple of millimeters was going to change that symptom. So we chose to excise most of that bone or all of that bone really in this case, which mostly was hypertrophied and heterotopic ossification type of bone within the hamstring tendon origin. So here we are debreeding all of that abnormal bone and debreeding and peeling it away from the hamstring tendons themselves, and we performed essentially a primary hamstring repair after that. This is another case where debreedment was useful. This is a 15-year-old male who in this MRI here was about six months out from our original suture anchor repair of a very small sliver of bone on the avulsion fragment. He had a re-rupture after he was essentially completely rehabbed and back to football, and there was really minimal bone on the fragment at that time. So we debrided the fragment and the rest of the physis and performed again, essentially a primary hamstring repair, and that healed quite nicely. And he's now playing college football and that has held up really well. So in summary, think about initial tuberosity fracture as a source of pain in a patient that has a story involving especially sprinting and feeling a pop, especially if it's an adolescent male. Consider a surgery for these fractures if there is more than one to two centimeters of displacement. And as far as options go, you have screw fixation, suture anchors, or excision of the fragment and primary hamstring repair as your options. Thanks so much for your attention, and if you have any questions at all, please feel free to email me at the email address below.

Stephanie Meyer

University of Colorado

ischial tuberosity fractures

pelvic avulsion fractures

sports injuries