Review Question - QID 211891

Posterior Tibial Tendon Insufficiency (PTTI) Treatment Operative QID: 211891 (SBQ18FA.72)

QID 211891 (Type "211891" in App Search)

A 57-year-old man presents to the clinic with bilateral flatfoot deformity. On physical exam, standing evaluation demonstrates the deformities seen in Figure A. With double-leg heel rise, the hindfoot inverts bilaterally. Silfverskiold test demonstrates neutral ankle dorsiflexion with the knee extended and 15° ankle dorsiflexion with the knee flexed. Weight bearing AP and lateral foot x-rays demonstrate a Meary's angle of 12°, talonavicular uncoverage of 50°, and plantar gapping between the medial cuneiform and first metatarsal base. Which of following is an indication for a modified Lapidus procedure in this patient?

Type & Select Correct Answer

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Hindfoot valgus

54/1688

Meary's angle

93/1688

Talonavicular uncoverage

14%

233/1688

Plantar gapping between medial cuneiform and first metatarsal base

75%

1265/1688

Positive Silfverskiold test

32/1688

Select Answer to see Preferred Response

Plantar gapping between the medial cuneiform and first metatarsal base indicates instability of the first tarsometatarsal (TMT) joint. A modified Lapidus procedure is indicated in patients with flatfoot deformity and first TMT instability.

The modified Lapidus procedure involves fusion of the first TMT joint with concomitant distal soft tissue procedure, often a modified McBride, and/or a medial cuneiform osteotomy. A Lapidus, or TMT fusion, is indicated in patients with flatfoot deformity and first TMT arthritis, instability, hypermobility, or neuromuscular conditions. This procedure is performed in combination with joint-sparing procedures in the flexible flatfoot or arthrodesis procedures in patients with rigid flatfoot.

McCormick and Johnson discuss the use of medial column procedures for the treatment of forefoot varus in patients with adult acquired flatfoot deformity. They discuss the importance of restoring hindfoot and midfoot alignment with corrective procedures to recreate the "tripod" of the foot. They recommend medial column (NC or first TMT joint) arthrodesis if arthritis, instability, or hypermobility of these joints is present. If none of these problems exist, a Cotton (plantarflexion medial cuneiform) osteotomy may be performed.

Deland provided a comprehensive review of adult acquired flatfoot deformity. He discussed conservative and surgical treatment options for all 4 stages of deformity. He concludes that surgical intervention can be considered in all 4 stages of deformity to achieve proper foot alignment and maintain flexibility to optimize long-term patient outcomes.

Figure A: Clinical photograph demonstrating bilateral flatfoot deformity with medial arch collapse, hindfoot valgus, and forefoot abduction.

Incorrect Answers:
Answer 1: Flexible hindfoot valgus, as seen in this patient, is not an indication for a modified Lapidus.
Answer 2: Meary's angle of 12° is abnormal, indicating pes planus. It is not an indication for modified Lapidus.
Answer 3: Talonavicular uncoverage of 50° indicates forefoot abduction. Flexible forefoot abduction is best treated with a lateral column lengthening.
Answer 5: Positive Silfverskiold test indicates gastrocnemius contracture. This is best treated with a gastrocnemius recession.