How To Address Inferior Heel Pain

While plantar fasciitis is a common diagnosis for inferior heel pain, these authors emphasize the importance of a proper workup and differential diagnosis. They also offer pearls on conservative treatments such as corticosteroid injections and provide insights on surgical procedures such as plantar fasciotomy.

   When it comes to inferior heel pain, the most common diagnosis is plantar fasciitis. The well-known signs and symptoms include post-static dyskinesia, point tenderness to the plantar medial tubercle and radiating pain to the ankle and/or midfoot. While plantar fasciitis is the most common diagnosis, physicians should consider the long list of differential diagnoses for inferior heel pain.

   Many times, patients fail all manner of conservative care, go on to surgical intervention and fail to improve their symptoms because the initial diagnosis was incorrect or inadequate to treat the patient properly.

   One can find 80 percent of the information necessary to diagnose a patient successfully in the history and physical exam. Have a high suspicion of other etiologies of plantar heel pain if the patient does not fit nicely into the plantar fasciitis mold or does not respond to initial therapy. Examine the superstructure of the patient to see if the foot is compensating for a biomechanical abnormality in the leg. Inferior heel pain can be plantar fasciitis or it can be arch fatigue manifesting itself as inferior heel pain.

   Pain is a symptom that is difficult for the practitioner to assess and for the patient to describe. Key words are important in distinguishing different types of pain. Sharp, stabbing, burning, shocking, throbbing, aching and tingling are all words we should be using when asking patients about their pain in order to discriminate between mechanical and neurological pain. When you fully examine and palpate all surrounding joints, you may find pathology that could be causing pain that originates in the ankle, subtalar joint or midtarsal joints to the inferior heel.

   One may consider arthrography or diagnostic joint injections when there is no clear etiology for the patient’s inferior heel pain. Use the needle as an extension of the physical exam. If the local anesthetic takes away the patient’s pain, then you have a targeted area for therapy. In some cases, this may prove more beneficial than information one obtains with magnetic resonance imaging (MRI).

   The differential diagnosis may include:

   • plantar fasciitis;
   • calcaneal bony cyst/tumors;
   • plantar fibromatosis;
   • calcaneal intraosseous lipoma;
   • calcaneal stress fracture;
   • diffuse idiopathic skeletal hyperostosis (DISH) disease;
   • Reiter’s syndrome;
   • Baxter’s neuritis; and
   • medial calcaneal nerve entrapment.

   After arriving at a diagnosis, formulate a directed plan of therapy for not only that current visit but for the follow-up visit, always thinking about what to recommend to patients as the next step. Start with basic conservative therapy including modification of shoe gear. Many times, patients will only be wearing unsupportive sandals. Once patients get into more supportive tennis shoes, their symptoms lessen or resolve completely.

   Conservative therapy options also include changing shoe gear, strapping/ padding, stretching, physical therapy and passive and dynamic night splints. Other options are local anesthetic/corticosteroid injections in a series of up to three injections, custom orthoses or using a short leg walking cast for three weeks.

Pertinent Insights On Corticosteroid Injections

   After exploring the aforementioned options, physicians can move on to more aggressive conservative care including splinting and injection therapy. Patients may be fearful of getting injections in their heels as they are more Internet savvy and have probably entered a chat room or two regarding their heel pain. Many initially refuse an injection because someone told them it was worse than childbirth or passing a kidney stone.

   Make sure to prepare patients well. Use sodium bicarbonate in the injection to lessen the burning sensation of the local anesthetic. Spray the ethyl chloride until the skin blanches. Always inject from the medial aspect of the calcaneus, never the plantar aspect. Penetrate the skin quickly, inject slowly and remove the needle quickly. These tips will make for a more pleasant experience for the patient.

   Many theories abound as to what corticosteroid to inject. Our recommendations and practice are to use dexamethasone phosphate and/or triamcinolone (Kenalog, Bristol Myers-Squibb) in combination with a long-acting local anesthetic such as bupivacaine (Marcaine, Sanofi Aventis). The long-acting anesthetic gives the patient more pain relief while the steroids are acting to reduce the inflammation.

   If the patient fails trials of injection therapy and/or strapping and padding, one can progress to night splints/short leg walking casts while the patient is still in the acute phase. One may want to consider a low-Dye strap with “whale tail” pads in the patient’s shoe. If strapping/padding relieves the pain, fitting the patient for custom orthoses can be a good option.

Can Physical Therapy Modalities Have An Impact?

   There are a variety of physical therapy modalities that one can use in the first-line treatment of plantar fasciitis. DiGiovanni and colleagues performed a prospective study comparing the effectiveness of the typical Achilles/gastrocnemius stretch to a tissue-specific plantar fascia stretch.1

   The patient performs the plantar fascia stretch by crossing the affected foot over the contralateral knee. The toes of the affected foot should be maximally dorsiflexed in order to put a stretch on the plantar fascia. Instruct patients to stretch three times a day for 10 reps, holding the stretch for 10 seconds each time.1

   When it came to the plantar fascia stretch group, the study results showed significant improvement in the patients’ maximal pain and pain with first steps in the morning in comparison to patients who wore a prefabricated orthosis and performed Achilles tendon stretches.1

   There are other physical therapy modalities that can be important parts of a multimodal approach to successful treatment. These include icing, deep tissue massage, iontophoresis and nisplints. The benefits of these modalities are readily available to the patient and simply take a little time to instruct the patient properly. One can also use these techniques in combination. For example, performing a tissue-specific plantar fascial stretch in combination with icing or deep tissue massage over the plantar medial calcaneal tubercle can be effective.

Emphasizing The Importance Of The Biomechanical Exam

   A thorough biomechanical evaluation is necessary for all patients with inferior heel pain. In our experience, correction of biomechanical problems with a custom orthosis can have the most successful acute and long-term results. The acute problem is often a failure in the patient’s biomechanical stability.

   Besides the standard biomechanical measurements of relaxed calcaneal stance position and neutral calcaneal stance position, one must assess and address the forefoot-rearfoot relationship and sagittal plane dynamics. One can best examine the forefoot-rearfoot relationship with the patient lying prone, the lateral column loaded and the subtalar joint in neutral position. Many patients with collapsing pes planovalgus have a forefoot varus/supinatus component that compensates through collapsing the medial arch and everting the calcaneus. This subsequently causes strain on the plantar fascia, spring ligament and tibialis posterior.

   A varus forefoot post will help decrease the amount of collapse in the arch and eversion of the rearfoot. It is recommended to subtract 2 to 3 degrees from the initial measurement for correction of forefoot varus as many patients cannot tolerate a full correction.

Assessing The Potential Merits Of Radiofrequency Coblation

   Newer surgical techniques and technologies have emerged over the past five to 10 years. If the patient with inferior heel pain is recalcitrant to all conservative therapy and one has diagnosed the patient with chronic plantar fasciitis, surgical intervention may be the next step. As with conservative therapy, the surgeon may consider going from the least aggressive to the most aggressive surgical approach.

   Radiofrequency Coblation (Arthrocare) had developed out of the technology in the arthroscopic community. Following the theory that plantar fascial pain is due to more of a degenerative process than an inflammatory process, radiofrequency Coblation can induce an acute inflammatory reaction to allow the tissue to heal itself. The patient undergoes multiple stab incisions with the radiofrequency wand being buried into the plantar fascia with approximately 5 mm of separation between treatment zones.

   A more invasive procedure involves a skin incision that exposes the plantar medial attachment of the fascia and then the surgeon makes the same grid type pattern. Chronic processes in the body tend to stall because the milieu is stagnant. Coblation intends to jump-start the acute healing process. The literature notes good results not only with plantar fasciitis but also with Achilles tendinosis.2,3 This procedure facilitates an inflammatory response. Accordingly, nonsteroidal anti-inflammatory drugs (NSAIDs) are not recommended during the perioperative and postoperative course.

What About Plantar Fasciotomy Procedures?

   The multiple stab incision plantar fasciotomy has garnered favor in recent literature with good results.4 The procedure itself had been around for many years, stemming mostly from the peppering injection techniques in which a physician would make small holes in the plantar fascia with an 18-gauge needle to stimulate neovascularization as well as relieve the tension of the central medial band.

   The fasciotomy consists of 10 small stab incisions about the plantar medial tubercle in a 3-4-3 pattern in consecutive rows proximal to distal with a 64 blade on a beaver handle. Make the incision, use a hemostat for blunt dissection of the subcutaneous tissue and then insert the blade. The surgeon pushes and twists his or her hand to create the defect. Repeat this in the recommended grid pattern.

   Dress the wounds with Steri-Strips, Xeroform, 4x4 gauze and a soft roll. Have the patient wear a post-op shoe and allow him or her to bear weight as tolerated. The multiple stab incision technique has provided good results with fewer wound complications than the standard open technique. Patients in our practice who have undergone this procedure seem satisfied with good relief of their preoperative symptoms.

   The endoscopic plantar fasciotomy has had a waxing and waning popularity. There are some practitioners who perform this technique with great results.5 Visualization of the plantar fascia allows the surgeon to avoid most nerve complications as well as document and verify that only the medial one-third to one-half of the plantar fascia is transected. This is usually the majority of the central band. Other open or minimal incision techniques are popular and all usually include resection of the same amount of plantar fascia.

   The risk of over-aggressive transection of the fascia is destabilization of the longitudinal arch as well as cuboid syndrome. For those patients in whom it is necessary to release the entire band of the plantar fascia, a six-week period of non-weightbearing is recommended in order to allow the fascia to repair before weightbearing commences.

Keys To Releasing The First Branch Of The Lateral Plantar Nerve Compression

   Impingement of Baxter’s nerve can be a very debilitating condition. It also poses a significant diagnostic challenge. The symptoms tend to be subtly different and lab tests/radiographic techniques are generally not helpful. The pain often drifts and generally increases with activity. Pain radiates medial to lateral and can occasionally be tender with palpation of the proximal abductor hallucis muscle belly. There can be some sensory loss and motor weakness of the abductor digiti minimi since this is a sensory motor nerve. Not all patients can abduct their fifth toes. However, if there is a unilateral inability to abduct the fifth toe, it may be a clue.

   First-line treatment for Baxter’s neuritis involves attempting to relieve abnormal pronatory forces through the heel possibly to decrease the level of entrapment surrounding the nerve. However, the orthosis can sometimes pose a significant dilemma as some patients’ symptoms may worsen due to the pressure from the medial flare of the heel cup.

   Surgical treatment for Baxter’s neuritis involves exploration and decompressing the course of the affected nerves. It is imperative to identify and release the deep fascia of the abductor hallucis muscle as well as the medial slips of the plantar fascia. To release the deep fascia, incise the superficial fascia. Then reflect the abductor hallucis muscle belly plantarly to expose its deep fascia, which one subsequently releases. After a sufficient release, the surgeon should be able to manually palpate the released tunnels that the nerve courses through. One should ensure approximately two weeks of non-weightbearing while the incision and released fascial tissues heal.

In Conclusion

   Inferior heel pain has many etiologies. Proper diagnosis will allow the physician to treat the patients’ symptoms successfully. It is not always easy to make the proper diagnosis, especially when the normal treatment modalities are ineffective. Rule out rare but serious conditions including bony or soft tissue tumors. X-rays, MRIs, bone scans, EMGs, NCS and lab tests can be very useful in this regard at times. Do not be afraid to refer to a colleague/specialist for a second opinion or more extensive workup.

Dr. Lee is in private practice with the San Diego Podiatry Group in San Diego.
Dr. D’Amico is the Chief Podiatry Resident at Scripps Mercy/Kaiser in San Diego.

Dr. Green is the Director of Podiatric Surgical Residency at the Scripps Mercy Medical Center in San Diego. He is a Clinical Professor at the California School of Podiatric Medicine at Samuel Merritt University, and is a Fellow of the American College of Foot and Ankle Surgeons. Dr. Green is also a Clinical Assistant Professor at UCSD Medical School, a faculty member of the Podiatry Institute and has a private practice in San Diego.

References:

1. DiGiovanni BF, Nawoczenski DA, Lintal ME, et al. Tissue-specific plantar fascia-stretching exercise enhances outcomes in patients with chronic heel pain: a prospective, randomized study. JBJS-A 2003; 85-A(7):1270-1277. 2. Gomes JE, Kruel A, Müller LM. Mechanical changes induced by thermal stimulation in collagenous tissue. J Shoulder Elbow Surg. 2008 Jan-Feb;17(1 Suppl):93S-95s. 3. Liu YJ, Wang ZG, Li ZL, et al. Arthroscopically assisted radiofrequency probe to treat Achilles tendinitis. Zhonghua Wai Ke Za Zhi. 2008 Jan 15;46(2):101-3. 4. Benton-Weil W, Borrelli AH, Weil LS Jr, Weil LS Sr. Percutaneous plantar fasciotomy: a minimally invasive procedure for recalcitrant plantar fasciitis. JFAS 1998; 37(4):269-72. 5. Barrett SL, Kuo R, Tejwani N, et al. Endoscopic plantar fasciotomy: a multisurgeon prospective analysis of 652 cases. JFAS 1995; 34(4):400-406. 6. DiGiovanni CW, et al. Isolated gastrocnemius tightness. JBJS-AM 2002; 84(6):962-970. Additional References 7. Irving D, Cook J, Menz H. Factors associated with chronic plantar heel pain: a systematic review. J Sci Med Sport 2006; 9(1):11-22. 8. Landoff K, Keenan AM, Herbert R. Effectiveness of foot orthoses to treat plantar fasciitis: an randomized trial. Arch Int Med 2006; 166(12):1305-1310 9. Buchbinder R. Clinical practice: plantar fasciitis. NEJM 2004; 350(21):2159-2166.