Sensitivity and Specificity of Radiographic Detection of Canine Elbow Incongruence in an in Vitro Model

Abstract

Canine elbow incongruence is believed to be the consequence of underdevelopment of the radius. The purpose of this study is to determine the sensitivity and specificity of radiography to detect elbow incongruence in an in vitro model and to assess the optimal elbow angle and radiographic beam position. Five normal cadaveric canine left forelimbs were used. A four-pin, type 1 external fixator with a linear motor side bar was fixed to the cranial part of the radius of each limb and a 1 cm segment of bone was removed from the mid-diaphysis to allow radial shortening. Each elbow was subjected to the same protocol. They were radiographed at two different angles (90 degrees and 135 degrees) of flexion, with 10 different radiographic beam positions (centered on the humeral condyle, 3 cm cranial, 3 cm caudal, 3 cm distal, 3 cm proximal, 3 cm cranio-proximal, 3 cm cranio-distal, 3 cm caudo-proximal, 3 cm caudo-distal and on the shoulder joint) and at four different level of radial shortening (0, 1, 2 and 3 mm). In addition, a radiographic view centered on the elbows flexed at 135 degrees was made after simulating weight bearing. The acquired digital images were independently evaluated by three evaluators unaware of the elbows status. The elbows were judged normal, incongruent or borderline based on specific criteria. The sensitivity for detection of elbow incongruence at and beyond 2 mm was excellent at 90 degrees (median = 100% for all views) and good at 135 degrees (median = 80%) of flexion with no difference between examiners. The sensitivity at 1 mm of incongruence was unchanged at 135 degrees but was reduced at 90 degrees of flexion (median = 60%) with a significant difference between the evaluators. The specificity was significantly different between the evaluators and ranged from 70% to 90% at 90 degrees of flexion and from 50% to 80% at 135 degrees. The lowest specificities at 90 degrees were obtained with the proximal displacements of the X-ray beam. Simulating weight bearing significantly decreased the sensitivity at 1 mm (from 80% to 50%) and 3 mm (from 100% to 80%) of incongruence and slightly increased the specificity (from 55% to 65%). Radiography is a sensitive and specific test to detect moderate-to-severe radio-ulnar incongruence (2 mm and over) if the elbow is flexed at a 90 degrees angle regardless of the radiographic beam position. Finally, canine elbow incongruence appeared reduced after an in vitro weight-bearing simulation.

Elbow dysplasia and lesions of the medial coronoid process: correlation between tomographic and arthroscopic findings in thirty cases

“…This is explicable taking into consideration that the radial incisure of the ulna is a precocious site of structural alteration in CT and the morphostructural anomalies observed (hypodensites, irregularity, geodi, ostephytes, etc) can induce to the formulation of false positives. We also have to remember that for the peculiar spatial orientation of the PCM, the orthogonality between object and scans cannot be maintained for the whole phase of the acquisition and therefore it is possible that under critical conditions the machine can produce small artifacts (Van Bree and Van Ryssen 1995;Reichle et al 2000;Rovesti 2002;Blond et al 2005). It is difficult for the CT to establish the entity of alterations of the cartilage, an aspect which is more easily observable with the arthroscopic lenses.…”

“…(Olsson 1975;Guthrie and Pidduck 1990). It can be revealed in various forms, (FCP,UAP,OCD,INC) and if it is not precociously diagnosed it also leads, sometimes inevitably, to forms of severe arthrosis (Olsson 1975;Hornof et al 2000;Kunzel et al 2004;Blond et al 2005). The diagnostic procedure consists, besides the clinical examination, of a standardized radiographic examination according to the indications furnished by the International Elbow Working Group (IEWG), that however gives only information on the presence or lack of secondary osteoarthrosic damage (Van Bree and Van Ryssen 1995;Hornof et al 2000;Blond et al 2005).…”

“…It can be revealed in various forms, (FCP,UAP,OCD,INC) and if it is not precociously diagnosed it also leads, sometimes inevitably, to forms of severe arthrosis (Olsson 1975;Hornof et al 2000;Kunzel et al 2004;Blond et al 2005). The diagnostic procedure consists, besides the clinical examination, of a standardized radiographic examination according to the indications furnished by the International Elbow Working Group (IEWG), that however gives only information on the presence or lack of secondary osteoarthrosic damage (Van Bree and Van Ryssen 1995;Hornof et al 2000;Blond et al 2005). For this reason, in the last decade the use of second level imaging techniques as CT and arthroscopy, which has the undeniable advantage to offer both diagnostic and therapeutic options, has increased (Van Bree and Van Ryssen 1995;Bardet 1997;Van Ryssen and Van Bree 1997;Hornof et al 2000;Reichele et al 2000;De Rycke et al 2002;Rovesti 2002;Schultz et al 2004;Blond et al 2005;Martini 2006).…”

“…The diagnostic procedure consists, besides the clinical examination, of a standardized radiographic examination according to the indications furnished by the International Elbow Working Group (IEWG), that however gives only information on the presence or lack of secondary osteoarthrosic damage (Van Bree and Van Ryssen 1995;Hornof et al 2000;Blond et al 2005). For this reason, in the last decade the use of second level imaging techniques as CT and arthroscopy, which has the undeniable advantage to offer both diagnostic and therapeutic options, has increased (Van Bree and Van Ryssen 1995;Bardet 1997;Van Ryssen and Van Bree 1997;Hornof et al 2000;Reichele et al 2000;De Rycke et al 2002;Rovesti 2002;Schultz et al 2004;Blond et al 2005;Martini 2006). The present works is to be considered as a retrospective investigation performed on 30 articulations affected by elbow dysplasia to find a possible correlation between CT and arthroscopic findings of different nature and degree, contextually analyzing the possibilities and limits of each technique.…”

Avaliação radiográfica e tomográfica da articulação umerorradioulnar em cães

“…A incongruência umeroulnar pode ser causada por diminuição do rádio, da curvatura da incisura troclear da ulna em relação a tróclea umeral (WIND, 1981;FOURIE, 1998;BLOND et al, 2005;SAMOY et al, 2006;MICHELSEN, 2012) ou quando a cabeça do rádio é deslocada cranialmente à incisura ulnar, causando subluxação da articulação (PROKS et al, 2011). Essas alterações levam ao aumento da pressão no processo coronóide, processo ancôneo e consequente NUPA e FPCM (WIND, 1986;GEMMILL et al, 2005 O diagnóstico clínico é frequentemente realizado por exclusão radiográfica de outras causas de osteoartrose, presença de esclerose de osso subcondral em região do processo coronóide medial e dor à palpação na topografia do processo coronóide medial (PUCCIO et al, 2003).…”