Getting a Leg Up on Femoral Stress Fractures

Stress fractures are common among members of the military, runners, and endurance athletes. With an incidence of 31% in military personnel and 21% in track and field athletes, this area needs to be thoroughly understood by clinicians working in a direct access environment.

While femoral stress fractures only account for 5-7% of all stress fractures, there is currently no validated clinical decision rule to identify those at risk. So, we need to consider all factors when assessing and treating femoral stress fractures.3,8,13,14,15,16

What Causes a Femoral Stress Fractures?

Stress-related bone and soft-tissue injuries occur in response to an excessive progression of repetitive loading activities. These injuries develop when the extent of the micro-damage exceeds the ability of the remodeling process to keep up with the demands placed upon it. With regards to femoral stress fractures, during running, the largest bending moments about the anterior to posterior axes of the proximal femur occurs during the impact phase of loading response. As this occurs, the largest stress is then placed on the medial aspect of the femur.7

Who is at Risk?6,8

Stress fracture injury rates are highest in girls cross country, girls gymnastics, and boys cross country. In endurance athletes, female sex (odds ratio = 2.31) and a history of stress fracture (OR = 4.99) are significant risk factors. The presence of concomitant ipsilateral femoroacetabular impingement shows a higher incidence in both the general and military populations.9,10 Sudden increases in training volume, especially in relatively inactive individuals, also elevates risk.

What is the Clinical Presentation?6,11

Vague pain in the thigh that radiates into the hip and/or groin region can indicate a femoral stress fracture. Patients may also present with the following:

  • Anterior thigh (45.9%), hip (27.0%), and/or groin (8.1%) pain
  • Groin pain with single leg hop (70%)
  • Hip A/PROM not typically limited, but can be painful (femoral shaft stress fractures)
  • Gross limitation in A/PROM can be present in femoral neck stress fractures

What Special Testing Can We Use?1,2

The patellar-pubic percussion test can help identify femoral stress fractures. The sensitivity, specificity, and +LR shown below suggest that a positive result on this test may change the probability of a positive stress fracture diagnosis.

Patellarpubic Percussion Test
Reliability Sensitivity Specificity +LR -LR
.89 .89 – .96 .82 – .95 5.1 – 20.4 .06 – .75

The fulcrum test may also be useful when screening for stress fractures:

Fulcrum Test
Reliability Sensitivity Specificity +LR -LR
N/A 1.00 1.00 0.00

Is Conservative Management Effective?

Several case reports and case series show successful diagnosis, treatment, and return to sport following conservative management. Unfortunately, at this time, no high-level studies support physical therapy as an intervention in this population. In those cases of successful management, programs included progressive posterolateral hip strengthening, neuromuscular re-education, and a graded return to running/physical activity.4,5,11

Without the clinical decision rules for identification of fracture that are available for the foot/ankle (Ottawa Ankle Rules), knee (Ottawa Knee Rules, Pittsburgh Knee Rules), and cervical spine (Canadian Cervical Spine Rules), evaluation of a potential femoral fracture needs to be managed with the best available evidence. By taking into consideration patient demographics, subjective report of training volume/progression, and using tests/measures supported in the literature, we can more accurately identify those athletes in need of further radiological evaluation.

References
  1. Reiman et al. Diagnostic accuracy of clinical tests of the hip: a systematic review with meta-analysis. Br J Sports Med. 2012
  2. Reiman MP, Mather RC, Cook CE. Physical examination tests for hip dysfunction and injury. British Journal of Sports Medicine. 2015;49(6):357-361. doi:10.1136/bjsports-2012-091929.
  3. Weishaar M. Identification and Management of 2 Femoral Shaft Stress Injuries. Journal of Orthopaedic & Sports Physical Therapy. 2005;35(10):665-673.
  4. Ivkovic A. Stress fractures of the femoral shaft in athletes: a new treatment algorithm. British Journal of Sports Medicine. 2006;40(6):518-520. doi:10.1136/bjsm.2005.023655.
  5. Kang L. Stress fractures of the femoral shaft in women's college lacrosse: a report of seven cases and a review of the literature. British Journal of Sports Medicine. 2005;39(12):902-906. doi:10.1136/bjsm.2004.016626.
  6. Wright AA, Taylor JB, Ford KR, Siska L, Smoliga JM. Risk factors associated with lower extremity stress fractures in runners: a systematic review with meta-analysis. British Journal of Sports Medicine. July 2015:bjsports–2015–094828–8. doi:10.1136/bjsports-2015-094828.
  7. Edwards WB, Gillette JC, Thomas JM, Derrick TR. Internal femoral forces and moments during running: Implications for stress fracture development. Clinical Biomechanics. 2008;23(10):1269-1278. doi:10.1016/j.clinbiomech.2008.06.011.
  8. Bennell KL, Matheson G, Meeuwisse W, Brukner P. Risk factors for stress fractures. Sports Med. 1999;28:91-122.
  9. Carey T, Key C, Oliver D, Biega T, Bojescul J. Prevalence of radiographic findings consistent with femoroacetabular impingement in military personnel with femoral neck stress fractures. J Surg Orthop Adv. 2013 Spring; 22(1):54-8.
  10. Goldin M, Anderson CN, Fredericson M, Safran MR, Stevens KJ. Femoral Neck Stress Fractures and Imaging Features of Femoroacetabular Impingement. PM R. 2015 Jun;7(6):584-92. doi: 10.1016/j.pmrj.2014.12.008. Epub 2015 Jan 13.
  11. Weishaar M. Identification and Management of 2 Femoral Shaft Stress Injuries. Journal of Orthopaedic & Sports Physical Therapy. 2005;35(10):665-673.
  12. Bennell KL, Malcolm SA, Thomas SA, et al. Risk factors for stress fractures in track and field athletes. A twelve- month prospective study. Am J Sports Med. 1996;24:810-818.
  13. Milgrom C, Giladi M, Stein M, et al. Stress fractures in military recruits. A prospective study showing an unusu- ally high incidence. J Bone Joint Surg Br. 1985;67:732- 735.
  14. Matheson GO, Clement DB, McKenzie DC, Taunton JE, Lloyd-Smith DR, MacIntyre JG. Stress fractures in athletes. A study of 320 cases. Am J Sports Med. 1987;15:46-58.
  15. Monteleone GP, Jr. Stress fractures in the athlete. Orthop Clin North Am. 1995;26:423-432.
  16. Changstrom BG, Brou L, Khodaee M, Braund C, Comstock RD. Epidemiology of Stress Fracture Injuries Among US High School Athletes, 2005-2006 Through 2012-2013. American Journal of Sports Medicine. 2014;43(1):26-33. doi:10.1177/0363546514562739.