Medial tibial stress syndrome
Medial tibial stress syndrome (MTSS), also known as shin splints, describes a spectrum of stress injury that occurs at the medial tibia. This term is often used to indicate any type of tibial stress injury or the earlier manifestations of a tibial stress lesion before a fracture component can be identified 1. It is considered a low risk stress fracture.
Typically occurs in athletes (e.g. runners/jumpers) and is characterized by localized pain that occurs during exercise at the medial surface of the distal two-thirds of the tibial shaft.
A "one-leg hop test" is a functional test, that can be used to distinguish between MTSS and a stress fracture: a patient with MTSS can hop at least 10 times on the affected leg where a patient with a stress fracture cannot hop without severe pain 2.
CT is not particularly sensitive (~40%) 3. It may reveal mild osteopenia as an early sign of fatigue damage of cortical bone in tibial diaphysis 3,4.
May show focal hyperechoic elevation of the periosteum with irregularity over the distal tibia and increased flow on Doppler interrogation.
MRI is the most sensitive radiological examination (~88%) 3. It may demonstrate a spectrum of findings ranging from normal to periosteal fluid to marrow edema to actual stress fracture 5. The medial cortex (+/- posterior cortex) is most commonly affected 3.
These findings are graded using the modified Fredericson classification system which allows grading of the MRI findings with a good correlation with clinical severity and outcome. It allows an estimate to a safe return to activity in athletes. It is as follows 7,8:
- grade 1: periosteal edema only
- grade 2: bone marrow edema appreciated only on T2-weighted sequences
- grade 3: bone marrow edema appreciated on both T1 and T2-weighted sequences
- 4a: multiple discrete areas of intracortical signal changes
- 4b: linear area(s) of intracortical signal change correlating with a frank stress fracture
Bone scintigraphy is relatively sensitive (~75%) 3 and may demonstrate high uptake in the affected region, characteristically along the posterior tibial aspect on lateral views.
- tibial stress fracture: there can be some overlap depending on the definition.
- 1. Bergman AG, Fredericson M, Ho C et-al. Asymptomatic tibial stress reactions: MRI detection and clinical follow-up in distance runners. AJR Am J Roentgenol. 2004;183 (3): 635-8. AJR Am J Roentgenol (full text) - Pubmed citation
- 2. Batt ME, Ugalde V, Anderson MW et-al. A prospective controlled study of diagnostic imaging for acute shin splints. Med Sci Sports Exerc. 1998;30 (11): 1564-71. Med Sci Sports Exerc (link) - Pubmed citation
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- 4. Gaeta M, Minutoli F, Vinci S et-al. High-resolution CT grading of tibial stress reactions in distance runners. AJR Am J Roentgenol. 2006;187 (3): 789-93. doi:10.2214/AJR.05.0303 - Pubmed citation
- 5. Anderson MW, Ugalde V, Batt M et-al. Shin splints: MR appearance in a preliminary study. Radiology. 1997;204 (1): 177-80. Radiology (abstract) - Pubmed citation
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- 8. Richard A. Marshall, Jacob C. Mandell, Michael J. Weaver, Marco Ferrone, Aaron Sodickson, Bharti Khurana. Imaging Features and Management of Stress, Atypical, and Pathologic Fractures. (2018) RadioGraphics. 38 (7): 2173-2192. doi:10.1148/rg.2018180073 - Pubmed
- 9. Amoako A, Abid A, Shadiack A, Monaco R. Ultrasound-Diagnosed Tibia Stress Fracture: A Case Report. (2017) Clinical medicine insights. Arthritis and musculoskeletal disorders. 10: 1179544117702866. doi:10.1177/1179544117702866 - Pubmed
- 10. Franklyn M, Oakes B. Aetiology and mechanisms of injury in medial tibial stress syndrome: Current and future developments. (2015) World journal of orthopedics. 6 (8): 577-89. doi:10.5312/wjo.v6.i8.577 - Pubmed
- 11. Moen MH, Tol JL, Weir A, Steunebrink M, De Winter TC. Medial tibial stress syndrome: a critical review. (2009) Sports medicine (Auckland, N.Z.). 39 (7): 523-46. doi:10.2165/00007256-200939070-00002 - Pubmed