Patient #19: Anterior Shin Pain .
History and Chief Complaint
- 22 year old professional ballet dancer presents with bilateral shin pain making it difficult to dance
- His dance company had recently finished a tour of Europe
- He complained that the European stages were more slanted (“raked”) than in the US. They all slant towards the audience.
- He said that the pain was level 5-6 mostly with an occasional 10 sharp pain that would quickly disappear
- He had some swelling pointing to the front of his shins
- It started on the right, but over a few weeks was equal on both sides
- He had felt some symptoms in the 3 weeks prior to leaving, but was afraid to say anything for fear of not being able to go
- He did not feel that he was limping
Question #1: Professional ballet, unfortunately, is a tough profession where dancing through pain is common. Imagine this dancer on a raked stage facing the audience balancing a ballerina with his arms. Is the convex side of the tibias bowed forward towards the audience?
Gait Evaluation
- Excessive External Angle of Gait walking
- Marked Tibial Varum
- Inverted Heels with Contact Phase Lateral Instability
- Excessive Shock at Impact
Question #2: The Biomechanics of most ballet injuries can only be assessed by watching ballet technique and not walking gait. Explain how the natural anterior bowing of the tibias can cause stress to occur? Also, how would that stress be increased on a forward slanting floor?
Physical Examination
- Perhaps slight swelling anterior right shin
- Palpable soreness along the anterior crest of the tibia both sides
- Bilateral tibial bone compression pain from anterior to posterior
- No ecchymosis or erythema
- Good strength and no pain testing anterior leg muscles (AT, EHL, and EDL)
Question #3: How would one perform the tibial compression test and for what purpose?
Cursory Biomechanical Examination and Asymmetry Noted
- Tibial Varum bilateral
- RCSP inverted right greater than left
- AJDF -5 (knee straight) right -2 (knee straight) left
- AJDF 15 knee bent both sides
Question #4: How does a tight gastrocnemius muscle/tendon affect the pull of the extensors?
Tentative Working Diagnosis
- Tibial Stress Fractures
Question #5: Making this diagnosis is based on experience treating ballet, compression testing, and pain levels. Explain how the dynamics of lifting a ballerina on a raked stage repeatedly can produce this problem.
Common Differential Diagnosis (2ndary Working Diagnosis)
- Anterior Shin Splints
Question #6: Our tentative diagnosis is in part based on what we must rule out first, and of course, what makes the most sense. How is the Common Differential Diagnosis typically made after the Tentative Diagnosis (in general)?
Occam’s Razor and Rule of 3
- Simplest Solutions are stretch achilles and strengthen anterior muscles
- Rule of 3 comes from our findings and experience: stretch super tight achilles, strengthen anterior shin muscles, and correct supination tendencies for better shock absorption since we are considering this a stress fracture until proven otherwise
Question #7: What in our gait evaluation led us to categorize this patient as a supinator?
Question #8: Why do patients with contact phase supination have poor shock absorption?
What Phase of Rehabilitation?
- Immobilization
Question #9: Does placing a patient in the Immobilization Phase mean that you have to place them in a cast?
Should We Image?
- Yes, bilateral tib/fib x rays were taken and the patient had 4 anterior crest stress fractures on each side
- One of the four stress fractures on each side had the “dreaded black line” of non-union and would need to be drilled
Question #10: Drilling across these fractures stimulates bone formation. What would be another one or two improvements to be added for bone healing?
First Decision: How to Reduce Pain 0-2
- Since the condition was on both sides, cam walker did not make sense
- He was taken off ballet and scheduled for surgery to drill into the bone defects to stimulate healing (it was March and wanted to try to have him ready for next September season)
- Exogen bone stimulator was used for 9 months on both sides
Question #11: In terms of healing any bone issue, how could you investigate the general bone health of the patient? In this case, bone health was found to be poor.
Second Decision: Inflammation Concerns
- Ice Packs only, no NSAIDs due to bone injury
Question #12: What is the Lewis hunting response to cold therapy?
Third Decision: Any Nerve Component?
- None apparent
Question #13: What 2 nerves are the most common causes of neuropathic pain to the anterior shin and what nerves are they off of?
Fourth Decision: Initial Mechanical Changes
- In this case, the biggest mechanical change was not dancing
Question #14: This injury is fairly unique to ballet due to the anterior bowing of the tibia coupled with the raked stage. What typical muscle imbalance feeds into this scenario or problem?
Common Mechanical Changes for Tibial Stress Fractures
- Simple to Complex Pronatory Measures
- Simple to Complex Supinatory Measures*
- Pure Shock Absorption Inserts*
- Shock Absorption Shoe Recommendations*
- Heel Cushions
- Leg Strengthening Exercises*
- Support Hose/Compression Hose*
- Appropriate Stretching Exercises*
- Shoe Selection*
- Training Techniques*
- Limb Length Discrepancy Lifts for Short Leg
I have starred the ones above that were used in the 6 months I worked with this dancer. The goal was to decrease the day to day shock absorption and leg stress with the dance instructors gradually increasing the return to ballet routine. He did not even start on small jumps (petite allegros) until mid July or 4 months after the surgery. Since his mechanics were supinatory, I used valgus wedges in all of his shoes to make him pronate for shock absorption. I switched his main walking shoe to a Hoka One One for maximal cushion, although I tended to see him in a similar Sketcher’s shoe which he loved. He wore a sports compression hose for support and venous return. He worked hard on extensor strengthening and achilles flexibility work. He missed the first part of the season, but was back for Nutcracker in November.
What is with the 4 stress fractures on both sides? The final conclusion was that every season he would break the tibias and then let them heal over the 3 summer months. Dancers will not only minimize their pain, but put off seeing anyone for fear of not being able to dance. Also, indoor sports are prone for stress fractures due to transient Vitamin D deficiency (especially in the winter months). This particular patient had major dietary issues, and chronic low Vitamin D. Part of the team to help him continue 10 more years in ballet was an endocrinologist who dealt with bone density issues and a sports nutritionist. Of course, early in the treatment, I ordered his first Vitamin D level (very low), and talked to him about a healthy diet.
Answers:
- Yes
- Convex side has a bending moment (rotatory torque) as it bows further due to perpendicular forces acting on the weakest point. The more raked the floor is the more bending moments are produced and the harder the ankle extensors and Achilles Complex has to work to keep the dancer upright.
- The tibial compression test is applied 1-2 inches above the point of maximum tenderness and one of the examiners forearms are behind the leg perpendicular to the tibia, and other hand pushes straight down on the tibia. Pain typically signifies problem at the bone level (but must not be done at painful spot from superficial palpation).
- The tighter the gastroc-soleus complex, the harder the extensors have to pull to do their job.
- The male ballet dancer is firing his extensors on this slanted surface, and with fatigue comes more ballistic contractions. When you add the weight of a 100 lb ballerina to the mix that must be supported, producing moments over 200 pounds greater, there is tremendous strain on the extensors.
- Xrays will be taken since you have to rule out the most serious of possible injuries. Of course, some stress fractures will not be seen until an MRI is performed. Once a tibial stress fracture is ruled out, then our treatment will be changed to our Common Differential Diagnosis of Shin Splints (much more benign).
- High Tibial Varum with Inverted Heels and lateral instability
- We need contact phase pronation for our shock absorption in our leg. Contact Phase supination robs the patient of that shock absorption mechanism.
- No, but of course it depends on your protocols for immobilization with each injury. In this case, no immobilization other than no dancing is required.
- Electrical bone stimulation
- Vitamin D and Bone Density workups
- After a period of cold, the capillaries open up to bring in massive amounts of blood.
- The nerve innervation to the tibia is a mixed bag. I typically think superficial peroneal nerve off the tibial nerve and saphenous nerve off the femoral nerve.
- The gastroc-soleus complex is so much stronger than the ankle extensors naturally creating a muscle imbalance that can feed into this scenario.
