Incidence and type of foot deformities in patients with spina bifida according to level of lesion

Aim: The previously suggested association between the incidence of high-level foot deformity and muscle imbalance is no longer supported, when evaluated independent from motor and sensory loss and level of lesion, by current studies. The purpose of this study was to evaluate the association between level of lesion and foot deformity.

Methods: Of 545 patients, a total of 136 (272 feet) patients admitted to the spina bifida clinic between 2010 and 2014 were included in this study. Levels of all lesions were evaluated using initial operation data, the motor-sensory exams, and direct radiography. All patients were categorized into four different groups: Thoracic region (group 1), high-level lumbar-L1-2 region (group 2), mild and lower lumbar regions (L3-4-5) (group 3), and Sacral region (group 4).

Results: The mean follow-up time was 34.9 months (range 8-176 months). Group 1, group 2, group 3, and group 4 included 24 (17.6%), 14 (10.3%), 19 (14%), and 79 (58.1%) patients with regards to level of lesion, respectively. The incidences of foot deformity were 85.4, 85.7, 81.5, and 50.6% in groups 1, 2, 3, and 4, respectively. Of all patients, 22% (61 feet) had clubfoot, 16% (44 feet) pes cavus, 10% (26 feet) pes valgus, 6% (17 feet) isolated equinus, 6 % (17 feet) pes calcaneus, and 5% (13 feet) metatarsus adductus. Patients without a foot deformity (81% of normal feet) usually had a lesion at the sacral level (p ≤ 0.05). On the other hand, isolated equinus (70%) and clubfoot (49%) deformities were mostly observed in spinal lesions (p > 0.05). The incidence of pes calcaneus, pes valgus, and adductus deformities inclined as the lesion level decreased (p > 0.05).

Conclusion: In this study, it was concluded that foot deformities were directly related to the level of lesion. The comparison of higher and lower level lesions revealed that the types of foot deformity differed significantly. The muscle imbalance due to spina bifida was not sufficient to explain the pathology. On the other hand, the level of spinal lesion is an important factor for the type of deformity.