Managing Stress Fractures In Athletes

When getting athletes back on their feet following a stress fracture, one must balance the need to return to sport with the need for safe healing. Combining a thorough review of the literature with practical pearls from his clinical experience, this author offers salient diagnostic insights and perspectives on non-weightbearing, bone stimulation and other treatment measures.

The treatment of stress fractures in athletes can be a challenging task. Athletes who are competing in school, professionally or at the highest recreational levels often have a narrow timeframe to train and compete in their desired sporting activities. Reducing healing time by every means possible is crucial to the success of these athletes and, in turn, achieving success as a sports medicine physician.

   The goal of any sports medicine professional should always be to return the athlete back to activity as soon as is safely possible for the athlete. Most competitive athletes will straddle the fine line between optimal fitness and injury in order to achieve the best performance possible.

   In 1855, Breithaupt first described stress fractures as “march fractures” and made the clinical description of swelling and pain in the foot of a metatarsal stress fracture.1 The fractures were closely associated with the marching of soldiers. In 1897, Stechow described the radiographic appearance in military recruits forced to go on long marches, establishing the association between stress fractures and overuse.2

   Matheson and colleagues analyzed cases of 320 athletes with bone scan positive stress fractures treated over 3.5 years and assessed the results of conservative management.3 The most common bone injured was the tibia (49.1 percent). This was followed by the tarsals (2.3 percent), metatarsals (8.8 percent), femur (7.2 percent), fibula (6.6 percent), pelvis (1.6 percent), sesamoids (0.9 percent) and spine (0.6 percent). Stress fractures were bilateral in 16.6 percent of cases.

What Are The Most Frequent Causes Of Stress Fractures?

Much of the literature points to overuse as one of the main causes of a stress fracture. Overuse or training errors can account for the extrinsic factors in an injury. However, there are typically other more intrinsic factors such as poor bone density, low body weight, weakness of the core muscles and biomechanical abnormalities including limb length differences, all of which can lead to a stress fracture. It is the duty of the physician to make the proper diagnosis and ascertain the possible cause to attempt to prevent future injuries.

   Fredericson and colleagues found that athletes who played ball sports such as basketball or soccer during childhood had a decreased incidence of stress fractures as adults.4 One can make a correlation that these athletes have developed better core musculature such as their hip abductors, which leads to fewer injuries.

   Fredericson, Akuthota and respective colleagues have further proven that improving hip abductor strength is the key component for treatment of iliotibial band syndrome.5,6 They note that improving hip abductor strength is also useful in the prevention and treatment of other lower extremity injuries such as Achilles tendonitis and medial tibial stress syndrome.5,6 Athletes are often searching for ways to improve performance and adding a core strengthening program is arguably the best way to help prevent injury leading to improved performance.

   Always question injured athletes about their dietary habits, in particular their ingestion of dietary calcium. A prospective study by Tenforde and co-workers in 2010 showed a decrease in stress fractures in runners when there was an increase of their dietary calcium and Vitamin D intake.7 A referral to an endocrinologist is appropriate when an athlete presents with any signs of an eating disorder or multiple stress fractures in a short span of time.

Essential Diagnostic Tips

In order to diagnose and treat stress fractures effectively, one must have a high index of suspicion during the initial clinical exam. Successful conservative treatment of a stress fracture is extremely dependent on timely diagnosis and initiation of treatment. Palpation of the injured area and careful documentation of the injury history are key components of making a proper diagnosis. Stress fractures are often accompanied by increased pain as the activity or workout progresses. This is the opposite of soft tissue injuries, which typically hurt more at the start.

   One diagnostic test that works well is having the patient hop on the injured side. This produces sharp, pinpoint pain. One may also use the hop test as another test to determine if the bone is healed enough for the patient to return to activity.

   Most physicians have radiographs readily available and with the advent of digital X-ray equipment, it is sometimes possible to pick up a stress fracture earlier than ever. It is important to keep in mind that negative radiographs should almost never rule out a stress fracture. Some bones such as the navicular or cuboid may never exhibit radiographic changes in the presence of a stress fracture. While metatarsal stress fractures can sometimes be present, it is typically at the point where the bone has healed and symptoms have subsided that there is radiographic evidence of bone healing.

   If initial radiographs are negative and further testing is required, then the physician can choose between magnetic resonance imaging (MRI), Tc99 bone scintigraphy and computed tomography (CT) scanning. There is some debate as to whether MRI or bone scan is better for diagnosing a stress fracture.

   Dobrindt and colleagues recently published an article supporting the use of bone scintigraphy.8 Three different observers studied bone scans without any clinical information about the patient for the diagnosis of stress injuries in 50 of 93 patients. Researchers found that the mean sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 97.3 percent, 67.4 percent, 77.7 percent, 95.6 percent and 83.5 percent respectively. An analysis showed a high agreement among the three different observers.

   Research has shown MRI to have a higher specificity for detecting the exact location for the injury. However, one must use caution in interpreting MRI results as bone marrow edema, which is commonly associated with a stress reaction or stress fracture, can also be seen in asymptomatic individuals. Amol Saxena, DPM, observes that further testing and correlation with clinical symptoms is extremely important.9 Dr. Saxena had a patient who was being evaluated for a sesamoid injury via MRI of the feet and legs as a screening prior to signing a professional soccer contract. The athlete had spent the morning practicing with a lot of ball strikes and the physician read the MRI as multiple stress fractures of the metatarsals despite the fact that the patient did not have any symptoms in that area.

   A CT scan is a much better option for some bones such as the navicular or cuboid, and when an MRI is inconclusive, and shows an increase of bone marrow edema. Computed tomography shows the cortex of bone much better than MRI.

Is Complete Non-Weightbearing Required To Facilitate Stress Fracture Healing?

A stress fracture is one of the few injuries in an athlete that requires almost complete cessation of weightbearing exercise. One exception to this rule is use of the Alter G treadmill (Alter G), which creates a vacuum around the runner and allows running at a reduced body weight of down to 20 percent.

   Takacs recently presented a case study of a patient with multiple stress fractures, who used the Alter G treadmill while rehabilitating from these fractures.10 The patient experienced a significant reduction in pain and an improvement in ankle range of motion, walking speed and physical function, which the researchers assessed via the Foot and Ankle Module of the American Academy of Orthopaedic Surgeons Lower Limb Outcomes Assessment Instrument. Training did not appear to have any adverse effect on fracture healing as was evident on the radiograph.

   A good general rule of thumb to guide treatment is that patients should avoid anything that causes pain. Use of a surgical shoe to offload the painful area will often suffice for metatarsal stress fractures. If the patient has pain when walking in a surgical shoe, then it may be necessary to move to a controlled ankle motion (CAM) walker. If pain is still present, then non-weightbearing may be warranted. The addition of a high ankle brace can be helpful with tibial and fibular stress fractures.

   Navicular stress fractures in particular occur in runners at a surprisingly high rate and require more aggressive conservative treatment. The Matheson study found that 25 percent of the fractures were of tarsal bones.3 The diagnosis and treatment of navicular stress fractures require a high index of suspicion and eight to 10 weeks of immobilization including non-weightbearing.

What You Should Know About Bone Stimulation

Bone stimulation may also help an injured athlete recover faster from a stress fracture. A study by Saxena showed that using a pulsed electromagnetic field allowed athletes to return much quicker from their stress fractures.11 Saxena presented a small, prospective, unblinded analysis of 73 stress fractures that were confirmed via bone scan, MRI or CT scan. The electromagnetic group returned to activity in 8.8 weeks versus the non-electromagnetic group, which returned to activity in 17.6 weeks.

   Beck and co-workers evaluated femoral stress fractures, and their whole group analysis did not detect an effect of capacitively coupled electric field stimulation on tibial stress fracture healing.12 However, greater device use and less weightbearing loading enhanced the effectiveness of the active device. More severe stress fractures healed more quickly with capacitively coupled electric field stimulation.

   Uchiyama and colleagues presented an excellent paper on the use of low intensity pulsed ultrasound in the treatment of anterior tibial stress fractures.13 These fractures are notoriously slow to heal. One aspect of this paper that differentiates it from other papers is the evaluation of the return to full activity for athletes, making it more applicable for sports medicine. Athletes returned to full activity two to three times faster with the use of bone stimulation in comparison to other modalities for the same injury.

   Further scientific studies are warranted but even a few weeks of added training can mean a great difference to a professional runner or a college or high school runner with a limited amount of eligibility to compete. The use of bone stimulation has almost no downside other than cost.

   Extracorporeal shockwave therapy (ESWT) is another modality that shows promise to help improve healing times for stress fractures. Taki and colleagues examined five athletes who had delayed or nonunions of stress fractures, and each injury showed significant improvements.14 The authors opined that ESWT promotes osteogenesis and helped these athletes heal faster.

   Moretti and co-workers also found that ESWT can speed the healing process.15 They conducted a retrospective study of 10 athletes affected by chronic stress fractures of the fifth metatarsal and tibia who received three to four sessions of low-middle energy ESWT. The authors concluded that at the follow-up (eight weeks on average), the clinical and radiography results were excellent, and enabled all players to gradually return to sports activities.

   These reports show that ESWT is a noninvasive and effective treatment for resistant stress fractures. Similar to the use of bone stimulation, there are no known negative effects for the use of shockwave therapy for stress fractures.

When To Attempt Surgery

When conservative treatment fails to heal a navicular stress fracture, one should proceed to open reduction internal fixation. Two articles show a faster return to activity following surgical management of navicular fractures than conservative treatment.18,19 Saxena and colleagues proposed an excellent classification system for the treatment of these injuries based on CT findings. This classification system is both prognostic and diagnostic.18

   Surgery is often a last resort but it is a viable alternative and the athlete should be assured that full return to activity should be attainable. Navicular type II and III injuries that do not heal within the six to eight weeks of conservative treatment will respond well to surgery. After conservative options fail, one should also consider excision of sesamoids that do not heal.

In Conclusion

The most important aspects of treating stress fractures in athletes involve making a timely diagnosis, the prevention of causative factors in the future and giving consideration to reducing the return to activity to the shortest possible time that is safe for the athlete.

   Dr. Fullem is a Fellow of the American College of Foot and Ankle Surgeons, and the American Academy of Podiatric Sports Medicine. He is board-certified in foot and ankle surgery by the American Board of Podiatric Surgery. Dr. Fullem practices in Tampa, Fla.

References

1. Breithaupt J. Zur pathologie des menschlichen fussess. Medizin Zeitung. 1855; 24:169-177.
2. Stechow. Fussodem und Rontgenstrahlen. Dtsch Mil-artzl Z. 1897; 26:465-71.
3. 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(1):46-58.
4. Fredericson M, Ngo J, Cobb K. Effects of ball sports on future risk of stress fracture in runners. Clin J Sport Med. 2005; 15(3):136-41.
5. Fredericson M, Wolf C. Iliotibial band syndrome in runners: innovations in treatment. Sports Med. 2005; 35(5):451-9.
6. Akuthota V, Ferreiro A, Moore T, Fredericson M. Core stability exercise principles. Curr Sports Med Rep. 2008 Feb;7(1):39-44.
7. Tenforde AS, Sayres LC, Sainani KL, Fredericson M. Evaluating the relationship of calcium and vitamin D in the prevention of stress fracture injuries in the young athlete: a review of the literature. PMR. 2010 Oct;2(10):945-9.
8. Dobrindt O, Hoffmeyer B, Ruf J, et al. Blinded-read of bone scintigraphy: the impact on diagnosis and healing time for stress injuries with emphasis on the foot. Clin Nucl Med. 2011; 36(3):186-91.
9. Personal communication with Amol Saxena, DPM.
10. Takacs J, Leiter JR, Peeler JD. Novel application of lower body positive-pressure in the rehabilitation of an individual with multiple lower extremity fractures. J Rehabil Med. 2011; 43(7):653-6.
11. Saxena A. Treatment of lower extremity stress fractures with pulsed electromagnetic fields (PEMF): A case-control study and comparison to the literature. Foot Ankle Quarterly. 2000; 13(2):43-50.
12. Beck BR, Matheson GO, Bergman G, et al. Do capacitively coupled electric fields accelerate tibial stress fracture healing? A randomized controlled trial. Am J Sports Med. 2007; 36(3):545-53.
13. Uchiyama Y, Nakamura Y, Mochida J, Tamaki T. Effect of low-intensity pulsed ultrasound treatment for delayed and non-union stress fractures of the anterior mid-tibia in five athletes. Tokai J Exp Clin Med. 2007; 32(4):121-5.
14. Taki M, Iwata O, Shiono M, et al. Extracorporeal shock wave therapy for resistant stress fracture in athletes: a report of 5 cases. Am J Sports Med. 2007; 35(7):1188-1192.
15. Moretti B, Notarnicola A, Garofalo R, et al. Shock waves in the treatment of stress fractures. Ultrasound Med Biol. 2009; 35(6):1042-9.
16. Saxena A, Fullem B, Hannaford D. Results of treatment of 22 navicular stress fractures and a new proposed radiographic classification system. J Foot Ankle Surg. 2000; 39(2):96-103.
17. Khan KM, Fuller PJ, Brukner PD, Kearney C, Burry HC. Outcome of conservative and surgical management of navicular stress fracture in athletes. Eighty-six cases proven with computerized tomography. Am J Sports Med. 1992; 20(6):657-66.

   For further reading, see “Identifying And Treating Stress Fractures And Lateral Ankle Sprains In Athletes” in the February 2010 issue of Podiatry Today, “How To Detect And Treat Running Injuries” in the May 2005 issue or “Secrets To Treating Stress Fracture Of The Ankle” in the June 2002 issue.