J Wrist Surg 2015; 04 - A010
DOI: 10.1055/s-0035-1567902

The CMC View: A Comparison of Three Radiographic Views by Eaton-Glickel Classification and Correlation to Clinical Disease Severity

D. Mercer 1, C. Salas 2, C. Carlston 1, N. Thompson 1, A. Lopez 1, M. Moneim 1
  • 1Presenting author
  • 2Primary investigator

Purpose: We introduce a new radiographic view of the wrist known as the “carpometacarpal (CMC) view” and compare this technique with commonly used X-rays of the hand (posteroanterior [PA] and Roberts view) using Eaton-Glickel (E-G) classification for characterization of disease severity. Radiographic staging is correlated to clinical disease severity through gross dissection of the joint in cadaveric hands.

Materials and Methods: Twenty fresh-frozen human cadaveric hands were X-rayed using the CMC, PA, and Robert views by a trained radiology technician. The CMC view is performed as follows:

  • Hand in a lateral position, wrist in ulnar deviation

  • 25° sponge placed under hand allowing true PA view of CMC joint

  • Thumb placed on sponge crest, hand rests on slope

Two attending hand surgeons and two hand fellows reviewed each image independently and staged each radiograph based on the E-G classification system. Inter-rater reliability (IRR) was calculated for all readings and for each view independently. One attending and one fellow surgically excised trapeziums. The trapezium, first metacarpal, and scaphotrapeziotrapezoidal (STT) joint surfaces were inspected. Descriptions of joint surfaces were graded using a 1–4 value corresponding with that of the E-G system, and these values were correlated to radiographic staging.

Results: Average pairwise Cohen's kappa (κ) of IRR using the E-G classification system across all views was 0.459. IRR for each view is as follows: 0.461 for PA, 0.411 for CMC, and 0.508 for Roberts. When comparing the E-G classification to clinical disease severity using each view, we found the following average pairwise κ values: 0.470 for PA, 0.447 for CMC, and 0.377 for Roberts.

Conclusions The CMC view is comfortable for the patient and allows for a clear view of the CMC and STT joints. IRR of E-G classification is lowest for the CMC view. The CMC view predicts clinical disease severity better than the Roberts view.