Weight-Bearing CT Scan After Tibial Pilon Fracture Demonstrates Significant Early Joint-Space Narrowing

Abstract

Background: Posttraumatic osteoarthritis (PTOA) is a common and early sequela of tibial pilon fractures resulting in substantial long-term disability. New approaches are needed to objectively and reliably quantify early disease progression in order to critically assess the impact of interventions aimed at preventing or mitigating PTOA. Weight-bearing computed tomography (WBCT) scans provide a means for measuring joint space while the ankle is in a loaded, functional position. We assessed the interrater and intrarater reliability of a standardized, regional method to quantify joint-space loss following tibial pilon fracture compared with the uninjured contralateral ankle. Methods: We prospectively enrolled 20 patients with intra-articular tibial pilon fractures that were surgically treated at 1 of 2 level-I trauma centers. Six months after injury, bilateral ankle WBCT scans were obtained. Joint space was measured by 4 reviewers at 9 discrete regions of the tibiotalar articulation on sagittal images. Measurements were repeated by reviewers 2 weeks later. To characterize the measurement method, interrater correlation coefficient estimates and test-retest reproducibility were calculated. Results: The mean tibiotalar joint space was 21% less in the injured ankles compared with the contralateral uninjured ankles (p < 0.0001). The middle-lateral and middle-central regions of the joint demonstrated the greatest decrease in joint space between injured and uninured ankles. The interrater correlation coefficient of the measurement technique was 0.88, and the test-retest reproducibility was 0.80, indicating good reliability and reproducibility of the method. Conclusions: We developed a simple, standardized, and reliable technique to quantify tibiotalar joint space following tibial pilon fracture on WBCT. Significant loss of joint space is seen 6 months after the injury. This tool can be used to longitudinally quantify loss of joint space following pilon fracture and assess the impact of interventions to reduce PTOA.

Assessment of Progressive Collapsing Foot Deformity Using Semiautomated 3D Measurements Derived From Weightbearing CT Scans

“…2,4 The recent introduction of weightbearing (cone-beam) computed tomography (WBCT) systems has enabled us to overcome the aforementioned shortcomings and allows an accurate assessment of foot and ankle disorders. 3,18,29,35 Studies have shown that WBCT allows for a reliable assessment of hind-and midfoot deformities in patients with PCFD. 9,16 However, most studies have used 2D measurements performed on single CT images to evaluate the deformity.…”

Comparative assessment of midfoot osteoarthritis diagnostic sensitivity using weightbearing computed tomography vs weightbearing plain radiography

“…While other studies do exist that measure foot and ankle alignment using WBCT vs. NWBCT or WBPR [27][28][29][30][31][32], to the authors' knowledge, no studies exist in current literature comparing the sensitivity and specificity of NWBCT and WBCT performance in midfoot OA. Recently, Willey et al used WBCT to demonstrate significant postoperative ankle joint-space narrowing in patients who underwent surgical treatment for a tibial pilon fracture [33].…”

Weightbearing Computed Tomography for Assessment of Foot and Ankle Deformities: The Iowa Experience

“…18,19 Syndesmotic instability, lateral ligament instability, Lisfranc ligament injury, hallux rigidus and post-traumatic conditions are gaining attention from the scientific community as the WBCT portrays a natural and physiological stress to the evaluated region. [20][21][22][23] Research focusing in WBCT applicability in knee and hip disorders are also increasing while new devices gain the capability of a more proximal evaluation. 24,25 As such, this study aims to report the University of Iowa's experience utilizing WBCT for the care of a large cohort of foot and ankle patients.…”