The Interrater and Intrarater Agreement of a Modified Neer Classification System and Associated Treatment Choice for Lateral Clavicle Fractures.
BACKGROUND
As there is substantial variation in the classification and diagnosis of lateral clavicle fractures, proper management can be challenging. Although the Neer classification system modified by Craig has been widely used, no study has assessed its validity through inter- and intrarater agreement.


OBJECTIVE
To determine the inter- and intrarater agreement of the modified Neer classification system and associated treatment choice for lateral clavicle fractures and to assess whether 3-dimensional computed tomography (3D CT) improves the level of agreement.


METHODS
Cohort study (diagnosis); Level of evidence, 3.


METHODS
Nine experienced shoulder specialists and 9 orthopaedic fellows evaluated 52 patients with lateral clavicle fractures, completing fracture typing according to the modified Neer classification system and selecting a treatment choice for each case. Web-based assessment was performed using plain radiographs only, followed by the addition of 3D CT images 2 weeks later. This procedure was repeated 4 weeks later. Fleiss κ values were calculated to estimate the inter- and intrarater agreement.


RESULTS
Based on plain radiographs only, the inter- and intrarater agreement of the modified Neer classification system was regarded as fair (κ = 0.344) and moderate (κ = 0.496), respectively; the inter- and intrarater agreement of treatment choice was both regarded as moderate (κ = 0.465 and 0.555, respectively). Based on the plain radiographs and 3D CT images, the inter- and intrarater agreement of the classification system was regarded as fair (κ = 0.317) and moderate (κ = 0.508), respectively; the inter- and intrarater agreement of treatment choice was regarded as moderate (κ = 0.463) and substantial (κ = 0.623), respectively. There were no significant differences in the level of agreement between the plain radiographs only and plain radiographs plus 3D CT images for any κ values (all P > .05).


CONCLUSIONS
The level of interrater agreement of the modified Neer classification system for lateral clavicle fractures was fair. Additional 3D CT did not improve the overall level of interrater or intrarater agreement of the modified Neer classification system or associated treatment choice. To eliminate a common source of disagreement among surgeons, a new classification system to focus on unclassifiable fracture types is needed.
Pain Research Center, Department of Orthopedic Surgery, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea oscho5362@dsmc.or.kr.
Chul-Hyun
CH
Cho
Department of Orthopedic Surgery, Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea.
Joo Han
JH
Oh
Department of Orthopedic Surgery, Gospel Hospital, Kosin University School of Medicine, Busan, South Korea.
Gu-Hee
GH
Jung
Department of Orthopedic Surgery, Pohang St Mary's Hospital, Pohang, South Korea.
Gi-Hyuk
GH
Moon
Upper Extremity and Microsurgery Center, Department of Orthopedic Surgery, Pohang Semyeng Christianity Hospital, Pohang, South Korea.
In Hyeok
IH
Rhyou
Department of Orthopedic Surgery, Kyungpook National University Hospital, Daegu, South Korea.
Jong Pil
JP
Yoon
Department of Orthopedic Surgery, Gyeongju Hospital, Dongguk University College of Medicine, Gyeongju, South Korea.
Ho Min
HM
Lee
D000293:Adolescent; D000328:Adult; D000368:Aged; D002968:Clavicle / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D005592:Fracture Fixation; D050723:Fractures, Bone / Q000145:classification* / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
Neer-Craig classification; agreement; fracture; interrater; intrarater; lateral clavicle; treatment