SLR - May 2017 - Kevin P. Patel
Reference: Kimura, Tadashi, Makoto Kubota, Tetsuya Taguchi, Naoki Suzuki, Asaki Hattori, and Keishi Marumo. Evaluation of First-Ray Mobility in Patients with Hallux Valgus Using Weightbearing CT and a 3-D Analysis System. The Journal of Bone and Joint Surgery. 2017 Mar; 99:247–55.Scientific Literature Review
Reviewed By: Kevin P. Patel, DPM
Residency Program: Temple University Hospital
Podiatric Relevance: Most studies to evaluate hallux valgus deformity focuses on sagittal and transverse planes displacement, but the inversion and eversion component should also be addressed. This study focuses on analyzing entire first ray three-dimensional (3D) mobility using weightbearing and nonweightbearing computed tomography (CT) images with 3D reconstruction of abnormal and normal feet. Therefore, this study will help demonstrate that hallux valgus deformity does not affect just the TMT joint, but it can cause significant displacement to the talonavicular joint, medial cuneonavicular joint and first metatarsophalangeal joint.
Methods: This is a case control study that examined 10 patients with no foot deformity and 10 patients with symptomatic hallux valgus between June 2014 and June 2015 at Jikei University Katsushika Medical Center in Tokyo, Japan. Exclusions criteria were hallux valgus with inflammatory arthritis or another foot condition. Standing radiographs were obtained for all patients with hallux valgus deformity. CT images of all patients were obtained first in a nonweightbearing position and then using a prefabricated device to simulate weightbearing. An outcome measure for foot parameter was hallux valgus angle, intermetatarsal angle, lateral talo-first metatarsal angle and calcaneal pitch angle. An outcome measure for mobility of medial column joints was assessed by evaluating displacement of proximal bone relative to the distal bone.
Results: There was strong correlation between angles used to measure foot parameters between standing radiographs and weightbearing CT. This would indicate that the prefabricated loading device can reproduce foot alignment in a standing position. Compared to the control group, at the talonavicular joint, there was significant displacement observed in the dorsiflexion of navicular relative to talus in the hallux valgus group. At the medial cuneonavicular joint, there was significantly greater eversion and abduction of the medial cuneiform compared to the navicular in the hallux valgus group. At the TMT joint, there was greater dorsiflexion, inversion and adduction observed of the first metatarsal relative to the medial cuneiform in the hallux valgus group. At the first MPJ joint, there was significantly greater eversion and abduction observed of the first proximal phalanx relative to the first metatarsal in the hallux valgus group.
Conclusion: The authors concluded that placing a foot in weightbearing position causes significant displacement not only at the TMT joint, but it affects the entire medial column joints. Overall, this article helps emphasize that hypermobility extends across the entire medial column and not only at the TMT joint. However, further study designs need to include the role of surrounding soft tissue as it plays a vital role in joint mechanics and stability.