Traditionally, hip arthroscopy is conducted on a post-based traction table. However, recently postless traction systems have been developed with purported benefits of minimizing perineal pressure and complications, simplifying patient positioning, and also potentially improving the range of motion of the instrumentation during surgery. Both of these are solutions for a key technical challenge in accessing the hip joint, which is optimizing your working space or distraction distance while at the same time minimizing the applied traction force and trauma across the hip joint. There is yet controversy regarding which one of these methods is most practical and or superior. Post-based traction methods provide a distal and lateral traction force vector, which may be advantageous. Theoretically, this may increase the working space available when instrumenting the hip. However, there's a greater potential for soft tissue injury given more rigid application of traction across the joint. Postless traction methods demonstrate a distally directed traction force vector with theoretically a smaller central compartment working space given less rigid application of traction. However, this is thought to minimize the potential for groin and soft tissue trauma. Our group set out to answer a couple of questions within this controversy regarding how traction application method, be it either post or postless traction, affects the traction forces throughout the duration of the procedure and also how distraction distance or working space is affected. To do this, we reviewed a single surgeon series of FAI patients. We used a historical control methodology with post-based distraction being the historical control and postless distraction being the intervention. An S-type load cell was retrofitted to the traction table to capture continuous traction force data. And then distraction distance was measured fluoroscopically using a normalized value for percent ephemeral head size. Regarding our results, you can see our demographics here. There were minimal differences in the demographics and clinical characteristics of the post-based patients and those that were operated on in a postless table. Age was very similar as well as was Baten score and alpha angle indicating that there are minimal changes in the demographics or indications for surgery across the two groups. Here regarding traction force, you can see the postless distraction data in the solid line and the post traction data in the dashed line. And you can see at all points measured during the surgery that the traction force was significantly less in the postless group, be it at maximal traction force, pre-venting, post-venting, pre-capsulotomy and post-capsulotomy. Regarding normalized distraction distance, I'll just draw your attention to this line here. Post-capsulotomy is perhaps the most clinically relevant as this is when one would be instrumenting the hip. And in the post group, you could see that the distraction distance was about 29% of the ephemeral head diameter. And postless distraction, although different, was minimally different at about 27% of the ephemeral head diameter for mean distraction distance. So in conclusion, postless distraction decreased overall traction force at all points during the procedure at which we measured the traction force. This amounted to a 20-25% reduction in traction force throughout the duration of the central compartment procedure. And this was associated with a minimal reduction in distraction distance or the available working space. So in summary, postless distraction is a useful tool for the hip arthroscopist to be able to minimize the traction force or trauma applied to the joint during distraction while at the same time optimizing the working space. Here are my references. Thank you.

post-based traction system

postless traction system

hip arthroscopy

traction force

working space