Medial Tibial Stress Syndrome….It’s not what you think !

A topic that I routinely cover during the F.A.P. Lower Limb seminars is the origin/cause of Medial Tibial Stress Syndrome, or MTSS.  One of the major ‘themes’ discussed during our seminars is that if you don’t know the anatomy involved in a clinical condition, you cannot expect to treat said condition effectively and/or efficiently.  Despite some recent articles describing the suspected pathoanatomical origins of this condition (see below), many practitioners still hold on to the premise that the condition is caused by excessive hypertonicity in the intermediate or deep posterior compartment muscles…. namely the soleus, tibialis posterior, of flexor digitorum have all been accused culprits.

Even without the surfacing of the recent literature debunking this myth, standard anatomical knowledge should have lead practitioners to question this premise as the location of pain associated with this condition, the distal third of the postero-medial tibia, is void of ANY muscular attachments (origins or insertions).  What does make strong attachments into the periosteum of this area is the Deep Crural Fascia (recall that the crural fascia is the name given to the fascial covering of the entire lower limb…as the Fascia Lata is to the thigh).  A description of this anatomy is given in this recently published article:

Stickley, Hetzler, Kimura, Lozanoff.  Crural Fascia and Muscle Origins Related to Medial Tibial Stress Syndrome Symptom Location.  Med Sci Sports Exerc 2009, 41(11):1991-1996.

Current theories as to the pathogenesis of this complicated condition are:

1. Traction induced injury – traction from what we now know has to be the deep crural fascia (DCF) may occur due to over training, or due to biomechanical error such as excessive subtalar over pronation.  This excessive traction leads to inflammation of the fascia along with periosteal irritation of the tibia itself.  Note that DCF inflammation has commonly been found in biopsies obtained from individuals with recalcitrant MTSS.
2. Tibial microbending – opponents of the traction-induced injury theory site tibial microbending as a probable cause, which leads to increased osteoclastic activity along the concave side of the bone.  Although a relationship between tibial microbending and MTSS has not been firmly established, this mechanism has been shown to be closely related to the development of tibial stress fractures which has long been considered a complication of ignoring MTSS (the believed predecessor)

With either of these theories one thing is certain, this condition cannot be treated as simple muscle tension, or in the same manner as tendonopathies. 

Dr. Spina’s view:  when managing any MSK related injury, one of my personal rules is as follows…..if there is bone pain associated with a condition, then that individual is taken out of practice/training/competition until such time as that bone pain resolves (ie. Palpatory pain on the bone itself).  If the pain is in the soft tissues alone, then the individual is allowed to continue activities during the course of treatment.  This “rule” also holds true for insertional tendonopaties as well.  In the case of MTSS, I have never had much success until I have had the patient take a break from the causal activities, during which time emphysis is placed on reducing the inflammatory component in the DCF and the tibia itself; the treatment/release of the deep crural fascia (if palpation findings lead me that way!!!); and correcting any abnormal lower limb joint coupling…. sometimes with the help of orthotics in order to dampen the shock of walking or running.

Once the bone pain has subsided, and a corrective rehabilitation program has been completed (focusing on correcting joint coupling of the lower limb and pelvis) a gradual re-introduction to activities is undertaken.

The moral of the story…the assumption that this condition is causes by muscular tension has lead to treatment plans that are not strict enough, and prognosis’ that underestimate the amount of damage actually occurring.