Femoral Neck Stress Fractures: Late Rehab

Stress fractures are very, very tough - and they can be even tougher in specific sites, like the femoral neck. The femoral neck is considered a high-risk site, meaning that it's at higher risk for non-union or requiring surgical treatment. Knowing this, recognition and prompt diagnosis becomes more important - which we talked about in the early stage rehab blog here

So once we're past the initial stage of non-weight bearing (usually 6-8 weeks in this region, but could be 12-14 in severe cases), we want to gradually re-load the bone. In the case of a femoral neck stress fracture, we'll often start with toe-touch or partial weight-bearing on the crutches for 1-2 weeks, followed by getting rid of the crutches and resuming 2-legged daily activities.

Pain is used as the guide for progression - we want these all to be pain-free, unlike most other running-related injuries, where mild pain is typically fine to continue progressing through.

While still in the partial weight-bearing phase, the athlete should continue doing pain-free, non-weight bearing exercises to reduce muscle atrophy and maintain tendon health.

In addition, I like to initiate double leg bodyweight exercises with an uneven weight distribution e.g. 75% on unaffected leg, 25% on affected leg. Obviously this is impossible to measure and very subjective; however, once you start walking, all of your weight is on that leg while the other leg swings - so I feel it's appropriate to start to partially load it before going straight into full weight-bearing ambulation.

Once fully weight-bearing with daily activities, the athlete can initiate a strength training program (now with equal weight-bearing on both legs). Focusing on the muscle groups most utilized during distance running is a good place to start. A very general & basic progression for the lower body could be something like:

  1. Double leg bodyweight squat, hinge, heel raise, bridge, modified side plank

  2. Double leg + add weight to the above, split squat or lunges

  3. Single leg bodyweight squat, hinge, heel raise, bridge, full side plank

  4. Single leg + add weight to the above

  5. Double leg plyometrics

  6. Single leg plyometrics

Each of the above stages of progression can last from 1-2 weeks depending on the severity of the injury, the athlete's tolerance, and the athlete's injury history. During this time, the runner can also be biking or swimming for cardiovascular fitness. From a running tolerance perspective, I also prescribe fast walks, starting with 15 minutes and working up to 45 at a brisk pace. 

Some examples of single leg exercises I'll have my athletes do post-stress fracture, pre-return to run are:

It's important that we don't have the athlete initiate a walk-run program until at least 12 weeks to allow the bone adequate healing time, even if clinical testing is free of pain. The average time to return-to-run following femoral neck stress fracture was 14 weeks in a study by Ramey & colleagues in 2016 (1). 

Once the runner is past 12 weeks, able to walk briskly for 45 minutes multiple times per week without pain, and is able to pass a battery of clinical tests (e.g. single leg step down, single leg squat, single leg heel raise, etc.), we'll initiate a return-to-run that consists of walk-run intervals. From there, the ratio of run:walk time gradually increases over a period of months (allll easy running) until the runner has made it back to their desired level. 

If you have questions about your own stress fracture rehab or that of your patient's, let's chat - schedule a free phone consult below!

Reference:

1. Ramey L N, McInnis K C, Palmer W E. Femoral neck stress fracture: can MRI grade help predict return-to-running time? Am J Sports Med. 2016