Abstract
Post-polio equinocavovarus deformity is a rare and disabling condition that can significantly impair ambulation and function. We report the case of a 66-year-old male with a rigid, flaccid paralytic equinocavovarus deformity following childhood poliomyelitis who underwent single-stage talectomy and tibiocalcaneal arthrodesis via a transfibular approach. Surgical goals included restoration of plantigrade alignment and accommodation of standard shoe gear. Postoperative recovery was uneventful aside from a superficial heel ulcer managed operatively. Radiographic fusion was achieved by 16 weeks, with angular correction confirmed using tibioplantar and Hibbs angles. At final follow-up (>4 years), the patient remained pain-free, brace-free, and fully functional without assistive devices. Single-stage talectomy with tibiocalcaneal arthrodesis provided durable correction, pain relief, and functional independence at >4-year follow-up.
Introduction
Severe neuromuscular foot deformity secondary to poliomyelitis, though uncommon in developed countries, remains clinically relevant as adult patients from endemic regions may present with long-standing, neglected pathology. Poliovirus infection leads to flaccid paralysis and chronic muscle imbalance, resulting in a broad spectrum of deformities, including rigid equinocavovarus, which can cause substantial functional limitation, abnormal gait, and progressive joint degeneration when untreated into adulthood. ,, Both gradual correction using circular external fixation and acute correction strategies, including talectomy, have been described for neuromuscular equinocavovarus deformity across multiple etiologies. ,,,, However, literature specifically addressing acute talectomy combined with tibiocalcaneal arthrodesis in adult post-polio patients remains limited, with most reports involving mixed etiologies or pediatric populations. ,,,, The present case describes a severe, fixed, unilateral post-polio equinocavovarus deformity treated with single-stage talectomy and tibiocalcaneal arthrodesis via a transfibular approach. This report highlights the importance of individualized surgical planning in complex neuromuscular deformity and demonstrates that acute correction can achieve a durable, painless, plantigrade foot with high patient satisfaction in carefully selected adult patients.
Case report
The patient is a 66-year-old Spanish-speaking male who sought medical attention for evaluation of a fixed right foot equinocavovarus deformity. Medical history was obtained from both the patient and his daughter. The patient had a BMI of 31, was a non-smoker, and had no known medical comorbidities. His foot deformity developed in early childhood following an unknown illness; no similar conditions were reported in his family. The patient was born in Mexico and did not receive vaccination against poliovirus. He has adjusted to the functional limitations it poses at his job where he is a laborer. The patient had no prior operative intervention and had been managed nonoperatively by another provider with activity modification and shoe gear adjustments, which failed to provide meaningful functional improvement. Preoperative patient-reported outcome measures were not obtained, reflecting the retrospective nature of this case; postoperative PROMIS metrics were therefore used to characterize pain and functional interference following surgical correction.
On examination, neurological findings and clinical observation suggested a static, flaccid paralytic deformity with no active dorsiflexion or peroneal muscle function present in the affected limb. The right ankle was fixed in equinus plantarflexion with a severe cavovarus foot deformity; the deformity was not passively reducible ( Fig. 1 e-g). Gait analysis revealed a “steppage” gait pattern. There were diffuse areas of callosities on the ball and dorsolateral aspect of the foot where the metatarsals and head of the talus were distinctly prominent and palpable, respectively. During stance, the right heel was elevated 5–6 cm from the weightbearing surface, and heel purchase could not be actively or passively achieved. Preoperative weightbearing radiographs demonstrated a rigid, multiplanar equinocavovarus deformity with degenerative changes to the tibiotalar and subtalar joint and anterior subluxation of the talus ( Fig. 1 a-d). Testing for poliovirus was completed and is consistent with signs of prior poliovirus infection ( Fig. 3 ). Confirmatory poliovirus titers were assessed via neutralization assay; infectious disease specialists were consulted for interpretation.
Preoperative radiographs and clinical photos demonstrating rigid, multiplanar equinocavovarus deformity with fixed equinus, midfoot cavus, and forefoot adduction.
Fig. 1 a–h. Preoperative radiographic and clinical evaluation of severe post-polio equinocavovarus deformity.
Fig. 1 a: Lateral radiograph showing fixed plantarflexion with anterior talar subluxation.
Fig. 1 b: Lateral Meary’s angle demonstrating severe midfoot cavus.
Fig. 1 c. AP ankle baseline radiograph.
Fig. 1 d: Tibioplantar angle confirming hindfoot plantarflexion.
Fig. 1 e: AP Meary’s angle demonstrating transverse plane forefoot adduction.
Fig. 1 f-h: This case features a severe, rigid equinocavovarus deformity with <10% passive reducibility on preoperative exam.
Talectomy with tibiocalcaneal arthrodesis was selected to address the severe, rigid, non-reducible deformity with associated joint degeneration. Complete talar excision was necessary to achieve adequate hindfoot mobility, reduce soft-tissue tension, and allow for plantigrade realignment. Tibiocalcaneal arthrodesis was then performed to provide durable stability in the absence of functional musculature. The patient underwent surgical correction on 03/19/2021.
Operative technique
A curvilinear incision approximately 10 cm in length was made over the distal fibula, extending distally along the lateral aspect of the subtalar joint toward the base of the fourth metatarsal. A fibular takedown was performed to create a transfibular approach, allowing direct visualization of the ankle and subtalar joints to facilitate total talectomy. The talus was completely excised, morselized, and reserved for autogenous bone grafting of the tibiocalcaneal fusion site. A complete Achilles tendon tenotomy was then performed to release the posterior soft-tissue contracture contributing to the equinus deformity. Given the flaccid paralytic nature of the deformity, no additional posterior compartment lengthening procedures were required beyond Achilles tenotomy, particularly following talar excision, which further reduced soft-tissue tension. The opposing tibial and calcaneal joint surfaces were denuded of cartilage and fenestrated to expose bleeding cancellous bone. A mixture of proximal tibial bone marrow aspirate concentrate and morselized autograft was packed into the tibiocalcaneal interface to enhance osteogenic potential and support reliable fusion. The limb was positioned to achieve plantigrade alignment, defined as a neutrally aligned foot with the plantar surfaces of the heel and forefoot in full contact with the weightbearing surface. The fusion surfaces were then reapposed under fluoroscopic guidance. Internal fixation was achieved using four 6.5 mm partially threaded headless screws placed from the calcaneus into the tibia in a crossed configuration to optimize compression and stability across the fusion site. Screw fixation was selected over intramedullary nail fixation due to the patient’s anatomy, absence of structural bone loss or segmental deficiency requiring load-sharing fixation, and the ability to achieve stable compression across the fusion site with a lower-profile construct. Although the talus was excised as part of the procedure, bone stock within the tibia and calcaneus was adequate to support screw fixation. Additional advantages included technical simplicity, versatility with the transfibular approach, and avoidance of intramedullary canal–related complications. Additional advantages included technical simplicity, versatility with the transfibular approach, and avoidance of intramedullary canal–related complications. Total operative time was 171 min, with estimated blood loss 100 mL. A pneumatic thigh tourniquet was applied at 275 mmHg for 90 min. Postoperatively, the patient received IV cefazolin every 8 h for 24 h and baby aspirin for DVT prophylaxis. He was maintained non-weightbearing for seven weeks, then advanced to protected weightbearing in a controlled ankle motion (CAM) boot until transition to a postoperative shoe at ten weeks and regular shoe gear by sixteen weeks. A superficial medial heel pressure ulcer developed between postoperative weeks 4–6, attributed to friction from postoperative immobilization. The wound initially responded to offloading and local wound care, with apparent resolution. However, the ulcer subsequently recurred, prompting operative management due to delayed healing. On April 28, 2025, the patient underwent right heel soft tissue biopsy, right heel bone biopsy, wound bed preparation (16.9 cm²), and application of a skin substitute. Persistent focal nonhealing led to a second procedure on June 6, 2025, consisting of right foot wound delayed secondary closure (0.66 cm²). Following this intervention, the wound healed definitively without further recurrence and without compromise of the underlying tibiocalcaneal fusion or final functional outcome.
Postoperatively, a mild residual pes cavus deformity ( Fig. 2 c–f) and limb length discrepancy were noted. Radiographic assessment demonstrated restoration of a plantigrade alignment of the right foot and ankle, with alignment confirmed by the relationship of the calcaneus to the tibial shaft and relationship of the calcaneal to the first metatarsal on lateral radiographs. Following talectomy, standard ankle-based angular measurements such as the tibiotalar angle are no longer applicable due to removal of the talus. Accordingly, alignment was assessed using alternative reproducible metrics, including the tibioplantar angle to evaluate sagittal plane hindfoot alignment relative to the tibial axis and Hibbs angle was used to assess midfoot cavus correction relative to the calcaneal axis. These angles were selected for their reproducibility and applicability in the absence of the talus. These measures allowed consistent pre- and postoperative comparison and correlated with clinical restoration of plantigrade alignment. The tibioplantar angle ( Fig. 2 a) improved toward neutral, and the Hibbs angle ( Fig. 2 b) demonstrated improved alignment, indicating correction of the midfoot cavus component. Radiographic fusion at the tibiocalcaneal interface was achieved by 16 weeks postoperatively, corresponding with a stable, painless, and plantigrade foot.
