Orthotic Management of Posterior Tibial Tendon Dysfunction

Carey Glass CPO, LPO, FAAOP
President, C.G.Medical, Inc.
North Brunswick, New Jersey
Adjunct Professor, Rutgers University Dept. Biomedical Engineering
New Brunswick, New Jersey

Over the past few years there have been many designs that claim to be the answer for controlling this condition and each claim has its pros and cons but no one has attempted to develop a protocol that can be followed by physicians and orthotists in determining the best orthosis for a particular patient. I've attempted to give the orthotist and physician a blue print to decide on the orthosis that might best suit the particular patient.

The information was compiled with specific criteria based upon the same diagnostic procedures used by physicians and podiatrists in formulating definitive diagnoses. The information was collected in the following order.

Etiology of posterior tibial tendon insufficiency and dysfunction

  1. Trauma

  2. Chronic flat foot

  3. Inflammatory arthritis

  4. Degenerative tendonopathy

Location and History of Pain

  1. Post-malleolar pain

  2. Aching arches

  3. Progressive dropping of the arch

  4. Forefoot pain and deformity

  5. Persistent Edema of foot and ankle

After assembling the medical history the next stage is evaluation of the foot in passive and active ranges of motion such as: gait (observed), palpation along the tendon, manipulation of the feet to check for hind foot and forefoot tightness, check double heel raise standing, single heel raise test, post-malleolar tenderness, swelling and mobility.

Imaging
X-rays, CAT scans, MRI's

The views used should include standing hind foot alignment, standing lateral showing and talonavicular of both feet, standing AP showing forefoot and talometatarsal alignment and best MRI tendon assessment position.

By compiling this information we are able to classify the stages of the posterior tendon dysfunction based on the Johnson classification (1989). It is at this point that the choice of orthosis was matched to the particular stage. In Johnson's classification of treatment the specific medical option is discussed but in this format we have substituted specific orthotic recommendations based on the particular stage.

TABLE1: Pathology staging systems by Johnson (1989)(1)

Orthotic Treatment Recommendations:

STAGE I: Correct biomechanical defect by using UCBL or Flexure hinged low profile AFO

STAGE II: Correct biomechanical defect and control deformity by maintaining control of the hind foot and keeping motion in the AP plane. AFO with metal type hinge free motion, AFO with metal adjustable joints to control dorsi flexion and plantar flexion or Arizona style AFO

STAGE III: Maintain control of foot to prevent further deformity and pain. Arizona or AFO solid ankle with malleolar padding.

These suggested orthotic treatments were varied based on deformity and pain control. In Stage III the orthoses were usually used in conjunction with surgical intervention, which required more immobilization that could later be changed based on the patient's recovery from surgery. In Stages I and II the orthotic control was increased or decreased based on individual deformity and pain levels.

The casting procedure and fabrication of the orthosis was one of the primary reasons for success in the orthotic management of the posterior tibial tendon dysfunction patient. Although physicians and orthotists are taught that talar neutral is the optimum position for casting, it was found that a variation of the position based on relief of pain and function were more important in the success of the orthosis. The patients who were cast in talar neutral in almost all cases required adjustment or re fabrication of their orthosis.

Although the correction of hind foot malalignment is important, in some of the Stage II and III cases it was not possible due to deformity or pain. In these cases varus or valgus heel wedges can be added progressively.

Conclusion

The study sample of 59 patients showed a 90 percent success rate in reducing excessive pronation, pain and tenderness when patients used their orthoses regularly with proper footwear.

The use of good clinical evaluation tools and casting techniques provided the posterior tibial tendon patient with good results. The collaboration between the physician and orthotist is a major key in providing the patient with the proper orthosis to aid in their treatment and rehabilitation.

References

  1. Johnson, K.A. and Strom, D.E. Tibial Posterior Dysfunction. COOR 1989:239: 196- 206

  2. Moore, K.L., Dalley, A.F. Clinically Oriented Anatomy 4th ed Philadelphia; Lippinkott Williams & Wilkins 1999: 595-602

  3. Nicholas, J.A., Hershman, E.B., The Lower Extremity and Spine in Sports Medicine 2nd Ed St Louis; Mosby 1995 23: 441-442

  4. Lin, S.S. Momi, K.S., Berkman, A.Janisse, D., Castro, E., Johnson, J.E. Nonoperative Treatment of Posterior Tibial Tendonitis Using Arizona AFO tm, presented at AAOS in Anaheim, Ca. Feb 5, 1999.