PT Classroom - Review of the Pathogenesis and Conservative Management of Stress Fractures of the Lower Extremity ׀ by Krista Formanek, DPT

Many studies on stress fractures are conducted in the military population due to consistency in training and readily available subjects. This creates problems with generalizing the results to the population of patients likely to report to physical therapy services in a more rural outpatient clinic. Regardless, the results provide techniques to guide initial treatment of patients with tibial stress fractures. The articles in this review consist mostly of a military recruit subject population, again because this population is widely researched in respect to tibial stress fracture pathology and treatment.

Tibial stress fractures are common injuries in runners, and females have been shown to have a greater risk than males. The study by Schaffer et al (2004) found that in female military recruits, a low aerobic fitness level and no menses for the past year were good predictors for development of a lower extremity stress fracture. In addition, female distance runners with previous tibial stress fractures had higher vertical force loading rates and peak tibial shock forces than females without history of stress fractures (Milner et al, 2006). The runners with increased vertical loading rates have a larger reaction force moving up from the contact surface and into their foot and tibia. This causes increased stresses on these bony structures and can lead to development of stress fractures. These females may benefit from education on proper alignment of the foot, ankle, knee and hip while running to avoid unnecessary and excessive stresses. When assessing female runners for potential causes of tibial stress fractures, Crossley et al (1999) found that body weight and height played a significant role in occurrence of stress fractures. For patients in the clinic, suggesting appropriate weight loss strategies would be beneficial to stress fracture treatment as well as the other weight bearing joints throughout the body.

Of the studies reviewed, ice and rest or activity modification were found to be superior to leg and shoe orthoses in treating tibial stress fractures (Johnston et al, 2006). Allen et al (2004) found no significant difference in improvements with or without the use of a pneumatic brace; however, the group wearing the brace had low compliance. The subjects felt the brace was awkward and uncomfortable. With adherence to treatment and continued use of this brace over a long period of time, abnormalities in gait mechanics and skin breakdown may occur and could lead to problems in the future in other joints, bony or subcutaneous structures. With this in mind, if a brace is used by a patient, proper fit needs to be ensured in order to avoid causing secondary problems related to the use of the brace. Ekenman et al (2002) found foot orthoses may decrease tibial strain in subjects without tibial stress fractures during walk but not while running on a treadmill. Patients that are at the lower and higher end of the weight spectrum (BMI under 19 or over 25 kg/m2) may benefit from use of an orthotic as a preventative measure in decreasing risk of developing stress fractures.

Conservative management techniques for tibial stress fractures lack supportive evidence. A few suggested treatments include pneumatic leg braces, shoe orthoses, and treatments including cryotherapy, stretching, strengthening, activity modification, rest and use of non-steroidal anti-inflammatory (NSAIDS) drugs. Future studies may find other treatments to be effective in managing tibial stress fractures, but current research supports ice and rest as the most beneficial strategy. Patient education regarding lower extremity biomechanics is also a key to preventing and decreasing stress fractures and the pain accompanying them.