Foot and Ankle cases 16

A 47-year old woman presents with 2 years of atraumatic hindfoot pain. She has noticed the gradual onset of pain that is worse in the morning and when first standing after sitting for long periods. Her review of systems is remarkable for episodic hip pain and diffuse morning stiffness. On examination, she is tender just anterior to the ankle joint, which has full motion. There is no heel tenderness. Radiographs of the foot were obtained (Fig. 5–30A and B).

 

 

Figure 5–30 A, B: AP and lateral radiographs of the foot.

 

What is the most likely diagnosis?

1. Plantar fasciitis

2. Posterior tibial tendon dysfunction

3. Talonavicular osteoarthritis

4. Talonavicular rheumatoid arthritis

 

Discussion

The correct answer is (D). It is not uncommon for RA to occur in the joints of the hindfoot and, in some patients, this is the initial presentation of the disease. The radiographs show isolated narrowing of the talonavicular joint. The lack of previous injury, combined with history of morning stiffness and other associated joint pain, support an inflammatory process as the diagnosis. Posterior tibial tendon dysfunction would not necessarily be associated with joint space narrowing. While “start-up” pain is characteristic of plantar fasciitis, the heel is not tender and symptoms have been present for 2 years.

Your patient returns 1 year later having been treated with medical management provided by a rheumatologist, who confirmed the diagnosis or RA. Further, there has been no relief with custom orthotics and a radiology-guided corticosteroid injection. Unfortunately, there is daily pain that significantly interferes with activities of daily living.

The most appropriate procedure would be:

1. Joint synovectomy and debridement

2. Isolated talonavicular arthrodesis

3. Triple arthrodesis

4. Interpositional arthroplasty

 

Discussion

The correct answer is (B). The diagnosis has been confirmed, nonoperative measures have been tried, and the patient remains substantially symptomatic. As such, surgery is reasonable. Isolated talonavicular fusion is the most appropriate option. The joint damage is too advanced for joint debridement. The other hindfoot joints are not significantly involved and therefore triple arthrodesis is not necessary. In the foot, interpositional arthroplasty is sometimes considered for the first metatarsal–phalangeal joint, but not for the talonavicular joint.

The patient has a nephew who is entering his first year of orthopaedic residency. She is concerned about loss of motion with isolated hindfoot fusion and decides to call him to inquire about this.

Loss of motion in which joint has the greatest effect on overall hindfoot motion?

1. Talonavicular

2. Calcaneocuboid

3. Talocalcaneal (subtalar)

4. Navicular–cuneiform

 

Discussion

The correct answer is (A). The three joints of the hindfoot are the talonavicular, talocalcaneal (subtalar), and calcaneocuboid. Together, these joints allow inversion and eversion of the foot, which in turn allows the foot to adapt to uneven ground. Another important concept to consider is that when the hindfoot is in valgus, as with heel strike, it is flexible and can better absorb ground reaction forces. When it is in neutral or varus, as with push off, it is more rigid and is a more effective lever.

A biomechanical study has demonstrated that eliminating motion at the talonavicular joint essentially eliminated motion at the other joints and that the talonavicular joint was the “key joint” of the triple joint complex.

 

Objectives: Did you learn...?

 

 

Discuss that it is not uncommon for inflammatory arthritis to affect the hindfoot? Describe the anatomy of the hindfoot as well as the associated biomechanics?

 

 

Describe the initial treatment of hindfoot inflammatory disease? Assess the appropriate surgical treatment for recalcitrant disease?