An amateur runner with hip pain and antalgic gaitBMJ 2016; 353 doi: https://doi.org/10.1136/bmj.i2400 (Published 03 May 2016) Cite this as: BMJ 2016;353:i2400
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Low serum testosterone levels and stress fractures. How low is low, and are they clinically meaningful ?
Hughes and Kluzek1 present a case of a tension-side stress fracture of the femur in a middle-aged amateur runner who had recently increased his running distance. The authors mention finding low serum testosterone levels, but this finding is not further explored in their paper. The questions that arise are: how low is low, and were these low testosterone levels reflected in the patient’s physical examination? After all, at issue is whether these low hormone levels thus should be considered of being of clinical significance or not. I certainly would be interested in hearing whether the authors believe this finding is instrumental to the injury, especially since it previously has been suggested that there is no relationship between subnormal testosterone and stress fractures in healthy young male athletes; when testosterone levels are decreased, they usually are still within normal ranges for adult men.2,3 These findings are distinctively different from what has been observed in women, where there exists a close and well documented association between endogenous sex steroid levels, at least as far as estrogen is concerned.4-6
Fatigue stress fractures are caused by the application of abnormal muscular stress or mechanical torque to a bone that has normal elasticity and mineral content.7,8 Bones are dynamic structures that respond to the external forces placed upon them, according to Wolff’s Law. However, this response in bone may be delayed when compared to muscle, since muscles typically adjust to increased demands at a faster rate than bone. Hence, fatigue fractures have previously been reported in various special populations subject to rapid changes in anthropometry, such as active children,9 or pregnant women.10
The case study presented2 required surgical intervention due to the suggested high risk of failure and completion of tension side fractures of the superior aspect of the femoral neck. The majority of stress fractures in both men and women can be treated conservatively, with attention for pain control, rest and physical therapy. Although pain control is often achieved by non-steroidal anti-inflammatory drugs, these drugs may impair the union of bone fractures due to their interference with Prostaglandin E2. Long immobilizations, while reducing physical stress, also may exert important negative effects and an increased risk for loss of muscle strength and physical fitness. This is an important concern when dealing with competitively active athletes. Depending on the duration of the immobilization and the age and health of the patient there is a further risk for deep venous thrombosis, pulmonary embolus, negative calcium balance, and osteopenia. In addition, lengthy periods of rest often may cause a significant gain in body mass, which is a strongly undesired effect for any athlete, but particularly for those injured athletes involved in weight class events.
Conversely, early mobilization and active life-style involving weight-bearing exercise will ―according to Wolff's Law― positively affect osteoblast activity and bone formation. Whether manual physical therapy contributes much to the positive evolution of this injury is debatable despite, apparently, often being prescribed by GPs and family physicians. Instead, novel noninvasive methods to promote fracture healing should be considered, including pulsed electromagnetic fields (PEMF), low-intensity pulsed ultrasound (LIPU),11 and especially, high-energy extracorporeal shockwave therapy (ESWT).12
1 Hughes HJ, Kluzek S. An amateur runner with hip pain and antalgic gait. BMJ 2016;353:i2400. Doi: http://dx.doi.org/10.1136/bmj.i2400.
2 Skarda ST, Burge MR. Prospective evaluation of risk factors for exercise-induced hypogonadism in male runners. West J Med 1998;169:9-13.
3 Barrow GW, Saha S. Menstrual irregularity and stress fractures in collegiate female distance runners. Am J Sports Med 1988;16:209-16. PMID: 3381976.
4 Choi H-J, Cho H-M. Multiple stress fractures of the lower extremity in healthy young men. J Orthopaed Traumatol 2012;13:105–10. Doi: 10.1007/s10195-011-0156-9.
5 Dugowson CE. Nontraumatic femur fracture in an oligomenorrheic athlete. Med Sci Sports Exerc 1991;23:1323-5. PMID: 1798372.
6 Lloyd T, Triantafyllou SJ, Baker ER. Women athletes with menstrual irregularity have increased musculoskeletal injuries. Med Sci Sports Exerc 1986;18:374-9. PMID: 3747798.
7 Fanciullo JJ, Bell CL. Stress fractures of the sacrum and lower extremity. Curr Opin Rheumatol 1996;8:158-62.
8 Whiting W, Zernicke R. Biomechanics of Musculoskeletal Injury – 2nd Edition. Champaign, IL: Human Kinetics; 2008, pp. 1-360.
9 Grier D, Wardell S, Sarwark J, Poznanski AK. Fatigue fractures of the sacrum in children: two case reports and a review of the literature. Skeletal Radiol 1993;22:515-8.
10 Schmid L, Pfirrmann C, Hess T, Schlumpf U. Bilateral fracture of the sacrum associated with pregnancy: a case report. Osteoporosis Int 1999;10:91-3.
11 Behrens SB, Deren ME, Matson A, Fadale PD, Monchik KO. Stress fractures of the pelvis and legs in athletes: a review. Sports Health 2013;2: 165-74. doi: 10.1177/1941738112467423.
12 Moretti B, Notarnicola A, Garofalo R. Shock waves in the treatment of stress fractures. Ultrasound Med Biol 2009;35:1042-9.
Competing interests: No competing interests