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

J Bone Joint Surg Am. 2020 May 6;102(9):796-803. doi: 10.2106/JBJS.19.00816.


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.

MeSH terms

  • Adult
  • Aged
  • Disease Progression
  • Female
  • Fracture Fixation, Internal
  • Humans
  • Male
  • Middle Aged
  • Osteoarthritis / diagnostic imaging*
  • Osteoarthritis / etiology
  • Prospective Studies
  • Tibial Fractures / complications
  • Tibial Fractures / diagnostic imaging*
  • Tibial Fractures / surgery
  • Tomography, X-Ray Computed / methods*
  • Weight-Bearing*
  • Young Adult