Medial-Tibial Stress Syndrome (MTSS)

Exercise related lower leg pain is common complaints among the athletes, and medial-tibial stress syndrome (MTSS) is one of the most common lower leg disorders which also known as shin splints. MTSS is an overuse injury and locates two-third along the posteromedial border of the tibia (Brunkner & Khan, 2012, p.748).

It clinically presents as diffuse tenderness and pain along the tibial border which has strongly associated with contributing factors such as abnormal structure of leg or foot, over duration or intensity of the activities, and individual’s physical history. However the tenderness usually alleviate with rest (Tolbert & Binkley, 2009)

Particularly running and jumping activities that MTSS accounts up to 17 to 22% among the lower

leg injuries (Epperly & Fields, 2001; Kirby, 2010). An excessive stress can increase damage to the bone that leads to tibial bending or fracture. The other biomechanical etiology that MTSS is caused by excessive posterior leg muscle tensile or traction forces on the medial border of the tibia (Tolbert & Binkley, 2009). Females have higher risk in developing MTSS than males (Strauch & Slomiany, 2008).

Clinical presentation
A 44-year old female presented to the uniclinic complaining soreness on medial side of the right lower leg.

She is a regular long-distance runner. Gradual onset of intense pain occurred for last two weeks since the recent ‘city to surf’ marathon competition. Pain was only occurred during running activities, 6 from VAS scale, but diminished when rest or walking. There was no history of trauma and the patient was otherwise fit and healthy with no relevant medical history or current issue and no known allergies.

Assessment
It is important to compare bilateral limbs always. She walked in normal without aids and no vascular, neurological or dermatological deficits were observed. Entire lower limbs were inspected and combination of forefoot valgus and tibial varum observed bilaterally. Foot posture index revealed she has a moderate pes planus both feet. No limb length discrepancy observed.
Palpation observed diffused tenderness about 10cm above medial malleolus in posteriomedial border of the right. This pain is hallmark of MTSS, but no bony irregularity, erythema or swellings were found. Tuning folk vibration did not exacerbate the pain, and hop test elicited a pain on the right tibia. Palpating through the relaxed overlying posterior leg muscles had no strains or rupture, but the right posterior thigh and calves were tighter. She had full range of active movement to knee and ankle joints, but ankle eversion of the right elicited pain. Passive resistance on the right foot eversion was weaker, but otherwise all within normal limits.

Possible ddx (referred to table 1)
- Tibial bone stress fracture
- Anterior compartment syndrome
- Arterial or nerve entrapment
- Deep venous thrombosis
- Fascial herniations
- Infection
- Muscle injuries
- Medial tibial stress syndrome
Usual footwear is brooks glycerin, neutral type, and it was heavily worn out from forefoot to medial longitudinal arch bilaterally.

If initial treatment unsuccessful and pain or warmth occurs at rest, a further diagnose will require to rule out other pathologies like MTSF (Tolbert & Binkley, 2009). May refer to MRI and orthopedist, which is able to detect swelling within soft tissue and bone. According to the assessments, a provisional diagnosis of MTSS was made.

Management

Aim is to decrease pain, increase functional mobility and early return to training. Advise patient to cease running for two weeks. Otherwise reduce training duration, intensity and avoid hard surface training (Galbraith & Lavallee, 2009). Recommend non-weightbearing exercises such as swimming or cycling to keep up her fitness without pain.

Ice massage over the medial border of tibia about 10 minutes twice daily to reduce the symptom of inflammation (Fogarty, 2014). Topical non-steroid anti-inflammatory drug (NSAIDs) gel such as diclofenac can help for pain

relief.

Modify shoe insoles or over-the-counter orthoses to reduce the symptoms. Felt padding through forefoot to midfoot varus extension with heel lift can initially benefit as shock absorption, anti-pronation and help the tightened posterior muscles (Galbraith & Lavallee, 2009).

Focusing on posterior leg muscles (Tolbert & Binkley, 2009). Tight hamstrings will cause a compensatory ankle dorsiflexion and increase stress on the lower leg. Towel stretch to warm-up before standing stretches begins. Stretch and hold for 15 to 30 seconds then release. Repeat 3 times.

Stretch and hold the hamstrings for 10 to15 seconds until a stretching sensation is felt. Perform 5 times each side with 15 seconds break. Repeat at least 3 times or as much as possible through a day. Stretching exercise for calves can improve running style more midfoot and rearfoot strikes as runners are usually forefoot strikers (Tolbert & Binkley, 2009).

Perform two eccentric stretches, heel-drop, of calves and hamstrings for 10 to 15 repetition, and perform all stretches 3 times each side with 15 seconds break. Repeat 2 times daily (Brunkner & Khan, 2012, p.789). Stretching anterior thigh and leg as holding for 10 to 15 seconds depends on her pain limit, and repeat 3 times daily both sides. Bilateral ankle range of motion exercise while sitting or standing for 10 times each direction. Perform this as many as possible through a day.

Strengthening therapy of the posterior muscle is to prevent weakening of the muscles and to reduce chance of developing MTSS. Perform ankle plantarflexion and inversion 10 to 15 times each side with 20 seconds break. Perform 3 sets each side for 2 to 3 times a day. Heel and toe raise exercise. Hold for 5 seconds each and perform 3 sets of 10 (Brunkner & Khan, 2012, p.767). Recommend anti-pronation running shoes like asics forte or kayano. Patient is to be reviewed in two weeks.

Custom foot orthoses which depends on patient response and for prevention purpose. Inverted orthoses with varus forefoot extension and medial heel skive to the symptomatic side that will decrease valgus bending and medial tibial border tensile forces during running cycle with heel lift to accommodate the tightened posterior muscles (Kirby, 2012). Thickness of wedge can then be modified.

Physical therapy modalities are beneficial such as deep tissue massages, trigger point release and extracorporeal shockwave therapy (ESWT). ESWT can expect promised interventions among chronic MTSS patients if they have tightness or focal thickening along the muscles (Moen et al., 2012; Winters et al., 2013)

Refer to physiotherapist and trainer for review and correct the training error or method. But in severe case, surgery like tibial fasciotomy may be performed with 70% success rate (Brunkner & Khan, 2012, p. 749).

MTSS usually resolve 6 to 8 weeks if the patient is an absolute compliant with the prescribed interventions, and continue the treatment regimen to prevent the reoccurrence. Keep monitoring the patient.

Conclusion

The etiology of MTSS can arise from many factors, and it is more of stress injury of the leg, which may or may not progress on to bone fracture. Structural risk factors that develop MTSS are abnormal alignment of forefoot, rearfoot and tibia with foot pronation, and tibia bone density.

A proper diagnosis should be made ruling out differential diagnosis, correction of poor techniques and an appropriate rehabilitation protocol are important. Treatment should be in combination of rest, ice, stretching and strengthening exercises with orthotic management and other physical modalities like ESWT.