Review Question - QID 218673

This older patient is found to have symptomatic rigid flatfoot deformity with competent deltoid ligament, consistent with stage III adult-acquired flatfoot deformity. These patients can be reliably treated with surgical correction of their deformity through a double (talonavicular and subtalar) or triple (+ calcaneocuboid) arthrodesis (Answer 4).

Adult-acquired flatfoot deformity (AAFD) is a progressive condition that begins with posterior tibial tendon insufficiency, whose primary function is to lock the transverse tarsal joints during the toe-off phase of gait. The resultant change in biomechanics leads to the classic hindfoot valgus deformity (Illustration A) with compensatory forefoot abduction (Illustration B), the loss of ability to perform a single-leg heel rise, and eventual medial arch support collapse (i.e. spring ligament disruption). At this point, there have not been any arthritic changes and the deformity has remained “flexible” (i.e. is correctable on physical examination). Osteotomies combined with soft tissue procedures can appropriately correct the deformity and notably improve patients’ quality of life. If left untreated, the initially flexible deformity becomes rigid secondary to midfoot peri-talar arthritis, as described in this patient. These patients require fusion procedures (i.e. double or triple arthrodesis) to correct the deformity and adequately relieve pain. If not, further deltoid ligament incompetency can lead to tibiotalar valgus, debilitating arthritis, and near-complete loss of ankle range of motion.

Jackson and colleagues performed an updated, comprehensive review regarding the management of AAFD. They discuss the relevant anatomy, sequence of progressive deformity, and tailored surgical treatment options dependent on the patient’s individual deformity (Illustration C). They conclude that while nonsurgical management is the mainstay for early disease, patients who fail conservative management or have progressive disease can be reliably treated with these tailored surgical treatment plans.

Mehta and colleagues performed a retrospective review of their institutional data on the radiographic corrections of stage III AAFD treated with modified triple arthrodesis. They reported significant radiographic improvements in all parameters, including the medial cuneiform to floor distance, talonavicular uncoverage angle, and lateral talo-first metatarsal angle (i.e. Meary angle). The authors concluded that their modified triple arthrodesis technique results in a reliable and reproducible correction of the deformity seen in rigid stage III AAFD.

Moore and colleagues performed a single surgeon, retrospective cohort study comparing the standard double-incision approach to their novel single-incision approach to performing a modified triple arthrodesis for stage III AAFD. They reported no statistical difference between both groups regarding deformity correction, wound healing, complications, reoperations, rate of nonunion, or improvements in VAS pain scores. However, they noted a significantly shorter surgery time with the single-incision group. The authors concluded that their single-incision lateral approach for triple arthrodesis was at least equivalent to those of the standard dual-incision approach.

Figure A is a radiographic image of a medializing calcaneal sliding osteotomy fixed with two headless compression screws.
Figure B is a radiographic image of a lateral column lengthening procedure performed via lateral opening wedge calcaneal osteotomy.
Figure C is a radiographic image of a combined medial calcaneal sliding osteotomy, lateral column lengthening, and medial cuneiform dorsal opening wedge (“Cotton”) osteotomy.
Figure D is a radiographic image of a triple (talonavicular, calcaneocuboid, and subtalar) arthrodesis.
Figure E is a radiographic image of a tibiotalocalcaneal fusion via intramedullary nail procedure.
Illustration A demonstrates hindfoot valgus seen on physical examination.
Illustration B demonstrates the compensatory forefoot abduction.
Illustration C demonstrates a comprehensive chart of the diagnosis and treatment options for AAFD provided in the Jackson article.

Incorrect Answers:
Answer 1: Medializing calcaneal sliding osteotomy procedures correct FLEXIBLE hindfoot valgus deformities (i.e. mainly stage IIa AAFD). They are most often combined with other soft tissue (PT debridement vs. repair, gastrocnemius recession vs. Achilles tendon lengthening, spring ligament repair or reconstruction) or bony procedures as indicated.
Answer 2. Lateral column lengthening procedures correct FLEXIBLE hindfoot valgus deformities, especially with excessive talonavicular uncoverage of >30% (i.e. mainly stage IIb AAFD). Similar to the medial calcaneal sliding osteotomy, lateral column lengthening is most often combined with other soft tissue and bony corrective procedures as necessary to restore a plantigrade foot.
Answer 3. The medial calcaneal sliding osteotomy and lateral column lengthening can be combined to manage severe FLEXIBLE hindfoot deformities (Stage IIb AAFD). If both procedures are performed and the forefoot remains in varus, a medial cuneiform dorsal opening wedge (“Cotton”) osteotomy should be performed. This will correct the residual forefoot varus and allow for a final plantigrade foot.
Answer 5. The tibiotalocalcaneal fusion nail is a relatively newer technique to treat end-stage (stage IV) AAFD where tibiotalar arthritis has developed. It is primarily reserved as a salvage procedure, as the tibiotalar joint provides the majority of the range of motion when performing ankle dorsiflexion/plantarflexion.