What is it?
Medial tibial stress syndrome (MTSS), which is also known as Medial Tibial Traction Periostitis, describes exercise-induced pain along the posteromedial border of the tibia (shin bone). The condition is commonly referred to as “shin splints” and is usually found in athletes and soldiers. MTSS is responsible for about 15% of all running injuries.
The condition affects the insertion points of the tibial fascia and deep ankle flexors along the shin bone. MTSS is believed to result from repetitive eccentric movements of the deep flexors during running, jumping, and impact loading. Repetitive traction on the shin bone, results in myofascial strain, inflammation, and bony stress reaction. The stress of exercise can weaken the bone.
The leading mechanism of injury is repetitive eccentric contraction from running or jumping on hard surfaces. Excessive or improper training is the leading cause of in the development of MTSS. Athletes that run more than 20 miles per week are at an increased risk developing this condition. Also, those that are inexperienced runners or with poor technique are at a greater risk.
Additional risk factors include a prior history of MTSS, increased BMI, higher pelvic tilt, increased internal rotation of the hip, a collapsing foot, and an excessive navicular drop.
Clinical Presentation
The clinical presentation of shin splints includes vague, diffuse pain over the shin bone. Athletes often present these symptoms following an increase in activity intensity or duration.
A clinical evaluation demonstrates diffuse tenderness over the tibial border. Prolonged stress to the area may generate a periosteal reaction that is detectable as a rough or bumpy feel.
Clinicians should assess for the presence of hypertonicity in the gastroc or soleus which is commonly present in patients with shin splints. Assessment of gait or running patterns can identify biomechanical errors that can be fixed.
Clinicians should also assess for potential risk factors, including inflexibility or imbalance of the hamstrings and the quadriceps. Postural issues should be taken into consideration for example genu varus or valgus, tibial torsion, femoral anteversion, and leg length discrepancies. Hip abductor weakness is a common contributing factor for many lower chain overuse injuries. Excessive external rotation of the hip is another known contributor.
Diagnosis
Imaging of early and uncomplicated medial tibial stress syndrome is often unnecessary. Radiographs taken within the first 2-3 weeks are not likely to show any change.
Imaging is appropriate with certain symptoms which include focal tenderness, pain at rest, or when the patient does not improve after a reasonable period of time with conservative care. Unresponsive patients or those with a higher likelihood of stress fracture may benefit from advanced imaging, including MRI, CT, or bone scan. An MRI is the best imaging to grade the progression of a stress reaction in the tibia.
Management
The successful management of medial tibial stress syndrome requires the removal of risk factors and selective rest. A clinician can help determine the combination of training errors and biomechanical risk factors that led to the development of the patient’s condition.
Athletes may need to decrease frequency, intensity, and duration of impact activities such as running and jumping. Athletes may also need to consider non-weight bearing cross-training like stationary cycling, swimming or running in a pool.
To solve MTSS it is important to correct any associated kinetic chain dysfunction. Stretching and myofascial release are appropriate for the gastroc, soleus, hip external rotators, tibialis posterior, and tibialis anterior muscles. Strengthening exercises may be appropriate for the tibialis posterior and hip abductors.
Manipulation should be used to resolve joint restrictions in the spine, sacroiliac joint, pelvis, and lower extremity.
Additional possibilities for the management of MTSS include dry needling or acupuncture. Patients can include ice or an ice massage in the acute phase to help with inflammation.
Return to activity should start slowly with a graded running program, for example beginning with one-fourth mile run and progressing by a fourth mile each time the athlete has no pain for two consecutive workouts. Athletes should initially avoid running on hard or uneven surfaces. Runners should begin at a lower intensity and distance, increasing by no more than 10-15% per week. Runners should also first increase distance, then pace, and avoid uneven surfaces such as hills. Running shoes lose half of their shock absorption capacity after 300-500 miles and should be replaced within that range.
Surgical interventions are very rarely indicated for medial tibial stress syndrome.