Hindfoot-Driven Cavovarus Deformity

Macalus Hogan

Hindfoot Deformity

Preoperative Evaluation

Patient history and physical
- In cases of a tight Achilles tendon, a lengthening procedure or gastrocnemius recession should be performed before any osteotomy procedure.
- This will reduce deforming forces on the heel.
Preoperative radiographic analysis critical to surgical indication and determination (Figure 8-1)
Visual inspection and gait analysis
Motor and neurologic assessment
Compare to contralateral extremity
Perform Coleman block testing: determine the presence of fixed hindfoot deformity, thereby warranting additional surgical correction¹ (Figure 8-2).
- Place patient’s heel and lateral foot onto a 2.5-cm block, permitting the first to fourth metatarsals (MTs) to fall into pronation.
- Block size may be increased to reduce weight-bearing impact of first MT.
- Obtain anteroposterior (AP) and lateral x-rays to document deformity changes with block.
Document and prioritize muscle imbalances that contribute to deformity recurrence.

Surgical Planning and Sterile Instruments/Equipment

Radiolucent operating room table
C-arm flouroscopy
Thigh tourniquet

Figure 8-1. Preoperative lateral radiograph demonstrates moderate cavovarus deformity with early degenerative changes.

Figure 8-2. Coleman block testing used to determine the presence of flexible versus fixed hindfoot deformity.
#15 blade
Small Hohmann retractors
Narrow sagittal saw
Kirschner wires (1.6- or 2.0-mm K-wires)
Implants
- 6.5- or 6.7-mm partially threaded cancellous screws
Rasp
Smooth-toothed calcaneal laminar spreader
Joker and/or Freer elevator
Sutures (nonabsorbable)

Positioning/Prep

Visually inspect surgical leg in preoperative area.
- Confirm there are no active ulcers/infections.
- Mark the operative extremity.
- Preoperative ankle block with 1% lidocaine and 0.5% bupivacaine typically adequate for hindfoot procedure
Position patient supine on the table.
- Heel should be positioned near the end of the table.
- Place a bump (centered at the level of anterior superior iliac spine [ASIS]) under the hip of the operative leg to increase foot internal rotation.
- May use either bone foam or sterile bump (surgeon preference) to improve access to the medial and lateral aspects of the foot
Well-padded calf tourniquet
Use a plastic shield barrier or foam tape to prevent skin breakdown secondary to retained operative prep.