Weight-Bearing CT Scans in Foot and Ankle Surgery

Matthew S. Conti, MD; Scott J. Ellis, MD

Disclosures

J Am Acad Orthop Surg. 2020;28(14):e595-e603. 

In This Article

Summary

The advent of cone-beam CT technology in place of conventional multidetector CT scanner configurations has made the development of WBCT scans possible. Cone-beam CT technology also has the advantage of reducing ionizing radiation exposure to the patient. It has two-thirds the effective radiation dose of a conventional CT scan but approximately 2.5 times as much radiation as a standard, three-view weight-bearing radiograph of the foot.[18] Compared with conventional nonweight-bearing CT scans, WBCT scans better demonstrate the true orientation of the bones and joints during loading conditions and help to identify underlying pathologies such as malalignment, impingement, and instability. They have provided new insight into common foot and ankle disorders such as AAFD, HV, ankle fractures, and lateral ankle instability. WBCT scans, however, have not replaced lower cost weight-bearing radiographs, which are often sufficient to adequately diagnose and manage most foot and ankle pathologies. At this time, WBCT scans may be better used as an adjunct. In clinical practice, WBCT scans may help surgeons assess subtalar and subfibular impingement and hindfoot alignment in AAFD. This technology may also help evaluate rotational deformities such as pronation of the first metatarsal in patients with HV. As WBCT scanners become more frequently used to evaluate foot and ankle pathologies, additional indications will soon emerge. Understanding the application of WBCT scans to clinical practice is becoming increasingly important for surgeons as they strive for better outcomes in the management of complex foot and ankle disorders.

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