Pertinent Roundtable Pearls On Orthotic Management

   These expert panelists expound on the use of orthotic treatment for a range of issues including hyperpronation, overuse injuries and posterior tibial tendon dysfunction. They also discuss treating pediatric patients with both flexible flatfoot and those with non-compensating equinus.

   Q: What are your insights into the orthotic treatment of pediatric flexible flatfoot following reconstructive surgery?

   A: Edwin Harris, DPM, divides the surgical management of pediatric flatfoot into two main types. The first type is implanting devices in the sinus tarsi to control excessive heel eversion. As he notes, it may be necessary to perform surgery on the medial column if there is a rigid sagittal plane deformity.

   The second category entails managing both triplane and transverse plane dominant pronation. Dr. Harris notes one can accomplish this by lengthening the lateral column and plantarflexing the medial column as close to the apex of the deformity as possible. For both types of surgery, he advises DPMs to consider the impact of ankle equinus.

   If one can perform a subtalar arthroereisis without doing osseous work along the medial column, Dr. Harris notes that subsequent orthotic control is not necessary. He does note an exception when either tendo-Achilles lengthening or some form of gastrocnemius/soleus recession is necessary to control equinus. For these patients, he prefers an ankle foot orthosis (AFO) for six months following surgery. Dr. Harris says the AFO protects the tendo-Achilles component of the surgery, preventing over-lengthening and rupture.

   Lateral column lengthening and medial column plantarflexing correction almost always require surgical management of the equinus deformity, according to Dr. Harris. Incorporation of bone graft into the lateral column in children occurs very quickly and he notes this does not seem to be influenced by either the use of an allograft or an iliac crest graft. Incorporation is usually complete by eight weeks.

   When it comes to osteotomies along the medial column, Dr. Harris follows the same aforementioned principles in postoperative management. When the patient no longer requires a cast, he places the patient in a solid ankle AFO for six months. After six months, he transitions the patient to a UCBL orthosis, which the patient wears for a year after surgery. At the one year mark, he will either continue use of a non-pronating orthosis or discontinue orthotic therapy altogether. However, Dr. Harris cautions that he does not necessarily recommend a solid AFO for all osteotomies of the medial column unless there has also been a surgery for equinus or a lateral column lengthening.

   For Scott Spencer, DPM, treatment depends on the procedure(s) one performs during the reconstruction. For subtalar arthroereisis procedures, he concurs that orthotics may be overkill. On the other hand, for most other procedures or a combination of procedures, he feels a functional foot orthotic device should be part of the postoperative management.

   Dr. Spencer notes the orthotic device one uses following flatfoot reconstruction should be designed to augment the correction. He adds that the device should also provide an extra layer of control and support while the patient heals and incorporates the surgical correction.

   Q: Hyperpronation has a direct association with the development of overuse syndromes. What is your rationale in the treatment of these problems with orthotics?

   A: Howard Dananberg, DPM, notes that the muscles of the foot and lower extremity are designed to act in a phasic manner, and there is delineation between stand and swing function. When muscles act out of phase, he notes many symptoms can be present. These symptoms may include shin splints, leg cramps, low back pain, arch fatigue, plantar fasciitis and heel strain. Dr. Dananberg emphasizes that the exam should focus not only on pronation but also on joint ranges of motion and muscle strength. As he notes, it is not unusual for a stronger muscle to be symptomatic because it is taking over the effect of the weaker muscles.

   Dr. Dananberg notes the existence of manual techniques for restoring motion and strength, particularly when the weakness is related to arthrogenic inhibition (weakening related to joint dysfunction, not disuse). These techniques include manipulation of the ankle, which he says can positively impact the strength of the peroneal muscles. When these muscles are weak, he notes anterior tibial overuse can develop with pain on the anterior lower leg.

   When treating overuse syndromes, Dr. Spencer considers two main factors. The first is addressing the activity that caused the overuse and modifying the patient’s activity. The second is addressing the abnormal motions that contribute to the overuse syndrome.

   Dr. Spencer emphasizes that one of the most important areas for an orthotic prescribed for an overuse syndrome is contouring the arch to the patient’s foot. He notes that the literature shows the arch of the orthotic is primarily involved in controlling leg rotation. As Dr. Spencer elucidates, one of the factors with overuse syndromes is leg rotation as a contributing factor to soft tissue stress, especially in the lower leg. By allowing the arch of the orthotic to closely conform to the arch of the patient’s foot, he says one can better address the leg rotation component of the pathology. Dr. Spencer adds that this will also allow any posting or other modifications designed to exert control over subtalar joint motion to work more effectively.

   As Dr. Harris notes, most of the patients with hyperpronation are athletic teenagers. He says the severity of the biomechanical disorder does not necessarily correlate with clinical symptoms. As he explains, many patients show transverse plane dominant pronation with some degree of fixed forefoot varus and many also exhibit residual tibia varum.

   Under these circumstances, such patients function with the calcaneus maximally everted. Dr. Harris says this severely diminishes the ability to dampen rotational movement, which is supposed to take place during running activities. He says designing an orthosis with the heel in slight varus and the forefoot accommodated will allow patients some frontal plane movement and relieve some of the stress on the lower limb.

   Q: What is your treatment plan for the pediatric patient who presents with a non-compensating equinus and a resultant painful heel and tendo-Achilles?

   A: Dr. Harris says for a long time, physicians have overlooked equinus in planning the management of pediatric flatfoot. He says there are several options for management of these patients. The first option is initiating physical therapy in an attempt to improve range of motion. Although this may be successful, he notes this approach requires a great deal of effort and adherence on the part of the child and the family.

   Alternatively, borrowing from the principle used in managing idiopathic toe walking syndrome, Dr. Harris says serial stretching casting may improve the range of motion. However, he says this may prove to be a problem because most of these children are older. If one uses this technique, it requires either casting one side at a time or casting both limbs at the same time, which he notes can be a hardship on both the child and the family. Although there may be some short-term success with heel lifts and gel cushions, Dr. Harris says the treatment is purely palliative and has no effect on the anatomical pathology.

   Appropriate surgical management of the equinus deformity is the ideal solution, according to Dr. Harris. However, he cautions that both the child and the parents may be very resistant to this form of therapy.

   Dr. Dananberg cites the efficacy of manipulating the ankle as a very effective method of care for such patients, noting that ankle manipulation has demonstrated “extremely positive” changes in motion.1 He says one of the most important features of manipulation is the neurologic effect on muscle strength, an effect one cannot attain simply by lengthening the Achilles tendons. He adds that aside from the neurologic change, the effect of manipulation is instantaneous in comparison to the months of recuperation and risk of excessive long-term weakness with tendon lengthening surgery.

   If the problem is an uncompensated equinus, Dr. Spencer says the main concern is the absence of heel contact during the gait cycle. In pediatric patients, he has found this is usually the result of congenital or spastic causes. He notes that age is an important factor along with the underlying cause of the uncompensated equinus. If the child is young enough, Dr. Spencer says one may employ serial casting or bracing, and make incremental adjustments to attempt to stretch the tendo-Achilles. For older kids, one can attempt stretching but in patients who have failed all conservative methods, he will refer them for surgical correction of the equinus.

   If the problem is apophysitis secondary to traction from the equinus deformity, Dr. Spencer uses a combination of stretching and functional foot orthotic devices. He has found that the orthosis’ decreasing plantar foot tension coupled with the stretching of the Achilles tendon results in rapid resolution of the condition due to the decreasing of traction forces pulling on the calcaneal apophysis.

   Q: What is your conservative orthotic approach in the treatment of posterior tibial tendon dysfunction (PTTD)? In patients who have undergone previous surgery, how do you control the foot postoperatively?

   A: Dr. Spencer conservatively manages the posterior tibialis dysfunction patient with either a functional foot orthotic device or a Richie style brace, depending on the severity of the condition. For patients with mild to moderate PTTD, he will use a functional foot orthotic device with a medial heel skive, wide width and somewhat deeper heel cup, close to a UCBL style device. In the more severe PTTD patient, he says a Richie style brace will permit the patient to function with the deformity.

   For patients who have undergone surgery for PTTD, Dr. Spencer will use a functional foot orthotic device that may incorporate a medial heel skive. He attempts to conform the arch of the orthotic device closely to the arch of the patient’s foot postoperatively and will initially order the orthotic in a wide width, which one can narrow as needed.

   For patients with PTTD, Dr. Dananberg says foot control should include some amount of inversion of the cast prior to the orthotic shell being pressed. He says this aids in the positioning and permits improved control of the foot. Dr. Dananberg emphasizes that manipulation is a very valuable technique that is underutilized for management of PTTD. For PTTD patients, he says it is the posterior tibial muscle that is inhibited as related to ankle equinus, and mobilizing it can be a very positive adjunct to care.

   Dr. Dananberg advises against over-posting of the orthotic as internal hip joint rotation is limited by rearfoot posting and orthotic inversion. He cites the necessity of balancing the patient’s needs with being mindful of more proximal function.

   Dr. Harris says that tibialis posterior dysfunction, as one would see in adult orthopedic medicine, implies inflammatory change in the tibialis posterior tendon. This change leads to varying degrees of degeneration and rupture, resulting in painful rigid or flexible acquired flatfoot. However, as a pediatric specialist, Dr. Harris say this pattern “is so seldom seen in the child that it may not even exist, except in children with seronegative or seropositive arthritis.” Some adolescents have pain from unstable accessory naviculars and Dr. Harris says one can best manage them by excising the accessory navicular alone if indicated or in combination with other flatfoot reconstruction procedures.

   However, if such a clinical pattern corresponding to adult tibialis posterior dysfunction should develop in the child, Dr. Harris says management requires control of the foot and ankle in all three planes, which one can only accomplish through the use of a solid ankle AFO.

Dr. Dananberg is in private practice in Bedford, N.H.

Dr. Harris is a Clinical Associate Professor in the Department of Orthopaedics and Rehabilitation at the Loyola Medical Center in Maywood, Ill. He is a Fellow of the American College of Foot and Ankle Surgeons.

Dr. Spencer is an Associate Professor of Orthopedics/Biomechanics at the Ohio College of Podiatric Medicine. He is also a Diplomate of the American Board of Orthopedics and Primary Podiatric Medicine.

Dr. Jay is a Fellow of the American College of Foot and Ankle Surgeons. He is a Professor of Foot and Ankle Orthopedics at the Temple University School of Podiatric Medicine and is board-certified in foot and ankle surgery. Dr. Jay is in private practice at Cumberland Orthopedics in Vineland, N.J. He is the author of “Pediatric Foot and Ankle Surgery,” which is published by Saunders/Elsevier.

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References:

1. Dananberg HJ, Shearstone J, Guiliano M. Manipulation method for the treatment of ankle equinus. JAPMA 2000; 90(8):385-89.