Reproducibility of radiographic classification of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist

Abstract

The aim of this study was to measure inter- and intra-observer agreement on the radiographic classification of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist. Radiographs of 41 patients with SLAC wrist and 47 patients with SNAC wrist were graded on two separate occasions by four orthopaedic consultants specializing in hand and wrist surgery. Inter-observer agreement was evaluated using the multi-rater kappa value. Landis and Koch criteria were used to assess the level of agreement. Intra-observer agreement was tested by re-grading the radiographs after an interval of 2 to 4 weeks and calculating the weighted kappa value. For SLAC wrist, the inter-observer agreement was moderate (kappa value = 0.59) and intra-observer agreement substantial (kappa value = 0.65). For SNAC wrist, the inter-observer agreement was slight (kappa value = 0.20) and intra-observer agreement was fair (kappa value = 0.29). Radiographic classification of SLAC wrist has moderate reliability and reproducibility, whereas classification of SNAC wrist has limited reliability.

Comparison of Magnetic Resonance Imaging and Radiographs for Evaluation of Carpal Osteoarthritis

“…One study showed moderate interobserver and substantial intraobserver reliability for SLAC, with kappa of 0.59 and 0.65, respectively. 17 For SNAC measures of reliability were lower with slight interobserver and fair moderate interobserver agreement (kappa: 0.20 and 0.29, respectively). 17 Another study demonstrated low interobserver agreement with kappa < 0.5 among five different readers, with the level of agreement being unrelated to the level of expertise of the reader.…”

“…17 For SNAC measures of reliability were lower with slight interobserver and fair moderate interobserver agreement (kappa: 0.20 and 0.29, respectively). 17 Another study demonstrated low interobserver agreement with kappa < 0.5 among five different readers, with the level of agreement being unrelated to the level of expertise of the reader. 18 The authors suggested that a more reliable method than radiographic staging is required to assess OA in these patients when planning treatment.…”

Arthroscopic Management of Scaphoid Nonunions

“…[1][2][3] With scaphoid nonunion, the wrist can frequently become pa inful with loss of function and progressive degenerative changes or carpal arthritis. To diminish symptoms and arthrosis over the long term, it has been emphasized that surgery for scaphoid nonunions should achieve a bony union and restore normal anatomy of the scaphoid and carpal mechanics.…”

Does a Comparison View Improve the Reliability of Staging Wrist Osteoarthritis?

“…Recent studies 13,20 concluded that SNAC staging based on anteroposterior (AP) radiographs has limited reliability. One possibility is that it can be difficult to distinguish between early stages of osteoarthritis and normal anatomy.…”