Conquering Medial Tibial Stress Syndrome
Tibial stress injuries have become an increasingly frequent reason for visits to sports medicine offices and clinics over the past decade. Unfortunately, these patients often leave the office with a diagnosis of shin splints. This nonspecific “diagnosis” has little clinical usefulness in light of the present day understanding of exercise-induced leg pain and, specifically, tibial stress injuries. The term “shin splints” merely describes a symptom of tibial stress injury and has little clinical or diagnostic value. Researchers have proposed many alternative terms to shin splints over the years. Most terms have a more descriptive anatomic and/or pathophysiologic basis. These terms include tibial stress syndrome, medial tibial stress syndrome, medial tibial syndrome, posterior tibialis syndrome, soleus syndrome and tibial periostitis. Tibial stress syndrome or medial tibial stress syndrome are the terms that most authors and sports medicine clinicians currently favor since Mubarek introduced the term (credited to Drez) in 1982.1 A diagnosis of medial tibial stress syndrome (MTSS) specifically excludes exertional compartment syndrome and tibial stress fracture (TSF). It offers the most accurate description of the involved anatomy and presumed pathophysiology of this most common form of tibial stress injury. With these points in mind, let us take a closer look at the diagnostic and therapeutic approach to MTSS. A familiarity with the current state of knowledge regarding exercise-induced leg pain, a logical, well directed history and physical, and appropriate special tests will help rule out other causes of exercise-induced leg pain that are beyond the scope of this article (see “Exercise-Induced Leg Pain: A Differential Diagnosis” below).2 Although one should not rule out any potential cause for chronic exercise-induced leg pain without a thorough history and physical, certainly one should have a higher index of suspicion for the most commonly encountered causes: MTSS, TSF and exertional compartment syndrome (ECS). Also keep in mind that two or more of these conditions may exist concurrently (e.g. MTSS and ECS) or sequentially (e.g. MTSS and TSF), causing symptoms to overlap and cloud the diagnosis. A thorough knowledge of anatomy and biomechanics as well as an understanding of the specific injuries will help the clinician sort these out. The lower leg is second only to the knee as the most common site of running injuries.3 However, it has been difficult to establish the precise incidence of MTSS (particularly in the general population) due to inconsistent definitions of the condition and the varied use of terminology in the past. Recent studies report up to a 35 percent incidence of MTSS in actively training military recruits and 13 percent in civilian runners.4 Bennett looked at high school cross-country runners over the course of a season and found 12 percent developed MTSS (19 percent in females).5 Taunton’s retrospective analysis of over 2,000 running injuries ranked MTSS as the fifth most common injury and, when combined with TSF, would be the third most common injury behind only patellofemoral pain syndrome and iliotibial band friction syndrome.6 By any measure, tibial stress injuries represent a significant cause of exercise-induced leg pain. Most recent studies rank MTSS as the leading cause of chronic exercise-induced leg pain ahead of TSF and ECS. I have found this to be the case in my own experience as well. Runners account for the majority of MTSS cases one sees in sports medicine practices although any running, jumping or cleated sport can contribute to MTSS cases.