Aworth is the primary author on this. He deserves all the credit for this study and this talk. He's not permitted to be on the panel twice via AOSSM criteria, and therefore I'm giving this talk. I'm the current president of ROC, but I'd like to thank not just Ben, but all of the authors on this. There were tens of thousands of hours for setup and this study included, and a special thanks to the late, great Alan Anderson and Lucas Murnahan. Our ROC surgeons have their disclosures on the Academy website. Funding directly related to this study was AOSSM Young Investigator Grant to Ben Hayworth. As background, OCD is a focal idiopathic alteration of subchondral bone with risk for instability and disruption of adjacent cartilage that may result in premature arthritis. This was a collective effort by our ROC group, but it was published by Eric Edmonds and Kevin Shea. Also really nice work by Jen Weiss out of LA to show that the lateral aspect medial femoral condyle is affected in two thirds of cases. In terms of background, these intact lesions arthroscopically appear as cue ball or shadow as previously published by our ROC group. There are two functional methods of non-operative intervention and these are activity restricting activities and impact loading and also unloader bracing and a variable use of unloader bracing and crutch use which have been shown to be efficacious in two thirds of cases to one half of cases as shown in separate studies out of Cincinnati and Boston. Trans-articular drilling has been shown by the late Alan Anderson and well as Min Coker to be efficacious in terms of healing times as well as radiographic outcomes and patient reported outcomes and that trans-articular drilling is the K wire is pushed through the cartilage and then drilled through the sclerotic bone to entice healing factors to enhance this process of healing. Retroarticular drilling is described out of Northwestern and also San Diego and similarly, excellent healing times, radiographic outcomes and patient reported outcomes. The purpose of this study was to compare the two most common drilling techniques in a prospective comparative randomized study which was only one of two orthopedic studies registered with the NIH at that time. The hypothesis was that trans- and retroarticular drilling would demonstrate similar rates of healing, time to return to sports and patient reported outcomes. There were 13 academic high volume centers and 17 surgeon investigators experienced with both techniques. There was clinical equipoise. The inclusion criteria was skeletal image for patients with stable OCDs of the medial femoral condyle that had failed non-operative treatment. Exclusion criteria is listed here to eliminate confounders of healing and knee function. Primary outcome measures were patient reported outcomes, pediatric IKDC and secondary outcome measures, patient reported outcomes of Leishon, Marks and Kuss as well as complications, time to radiographic healing and return to sport. Power analysis was performed and such that statistical significance would be obtained with a group sample size of at least 40. In terms of results, the patient's bone age, sex and demographic and pre-surgical factors were comparative in each group. In terms of the anatomic OCD features and treatment data, the wire size was for the most part 0.45 millimeter drilling and that was known beforehand and agreed upon by the group and 0.62 millimeter K wire for retroarticular drilling. Tourniquet time was higher in the retroarticular drilling group. In terms of functional outcomes and activity levels, both groups had significant improvement in all patient reported outcomes, baseline to six, 12 and 24 months and there was no difference between the groups in all patient reported outcomes in all time points. Radiographic healing of the OCD lesion did reveal differences. There was more complete healing in the transarticular group at six and 12 months. There was no difference between the groups at 24 months. Return to sports was seen earlier in the trans over the retroarticular groups as shown in what is here is a functionally a reverse survivorship analysis curve. Secondary surgery in terms of revision drilling, drilling and fixation, transarticular in 4%, retro in 10%, there was no statistical difference. In conclusion, transarticular drilling demonstrated shorter tourniquet time, fluoroscopy time, bony healing was greater at six and 12 months and return to sports was earlier. Both techniques demonstrated consistent interval healing, high rates of clinical improvement in return to sports prior to complete healing, which may not occur before one to two years and excellent patient reported outcomes at six, 12 and 24 months. There were also low revision surgery rates and both were safe effective techniques for surgical management of stable OCD in this series. However, long-term follow-up studies are needed to assess for possible DJD. The transarticular drilling group therefore may be technically simpler and more reliable, particularly for those who do not perform a high volume of these surgeries. Thank you.

drilling techniques

surgical management

osteochondritis dissecans

transarticular drilling

retroarticular drilling