Arthroscopy, a frequently used human diagnostic and surgical technique, now is being used in dogs to provide an alternative approach to study and diagnosis of joint diseases¹. The present study, performed in canine cadavers, evaluated the applicability of the arthroscopy as a diagnostic modality in the diseases that attempt the shoulder, elbow and stifle joints, in comparison with radiographic and macroscopic findings.

The arthroscopic examination was performed with a 2.7 mm 25° foreoblique arthroscope in a 4.0 mm outside-diameter sleeve. Handheld instruments included graduated probe and grasping forceps. The joint was distended and irrigated with Lactate Ringer´s solution. Light was supplied by a 150W halogen light source. The procedure was visualized via a camera mounted in the scope and a monitor. Preliminary studies on the articular anatomy of the elbow, shoulder and stifle had been carried out in canine cadavers. Ten animals were used in the experimental study, six males and four females, with average corporal mass of 30,8kg. Sixty joints (20 shoulders, 20 elbows and 20 stifles) were submitted to the radiographic and arthroscopic examination objectifying itself to evaluate the presence or absence of alterations that usually attempt these joints. The difficulties of technique and any complications during the arthroscopic procedures were gathered for posterior argumentation. After the arthroscopy, it was performed the arthrotomy of each joint, and its findings were stated as standard. The accuracy, sensitivity and specificity of the arthroscopy and radiographic examination were calculated to trace a comparative degree between the diagnostic techniques performed and to inquire the applicability of the arthroscopy. The evaluation was made by the agreement degree between the diagnostic methods using the Kappa statistics (k)². Fischer´s exact test was used to detect differences between the accuracy, sensitivity and specificity of the diagnostic techniques. The significant level was set at p<0,05.

By the radiographic examination, it could be mainly observed more serious injuries and in a more chronic stage, becoming in these cases, as efficient as arthroscopy, besides in some situations (ligaments calcifications) it makes necessary to associate both techniques. In spite of lack statistics evidences (in some cases), the arthroscopic examination demonstrated to be superior to the radiographic in sensitivity and accuracy, especially in the diagnosis of articular cartilages injuries.

The arthroscopic examination presented an agreement degree with arthrotomy always superior to that one observed in the radiographic examination, because it offered a direct magnified visibilization of the synovial surfaces, allowing the surgeon to detect very subtle articular alterations, and improving the precision in an eventual treatment procedure. Arthroscopy is an efficient diagnostic modality, able to propitiate early, accurate diagnoses possible in the affections that attempt the shoulder, elbow and stifle joints in dogs.

References

1. Goring, R.; Price, C. Arthroscopic examination of the canine scapulohumeral joint. J Am Anim Hosp Assoc. 1987; 23(5):551-55.

2. Landis, J.R.; Koch, G.G. The measurement of observer agreement for categorical data. Biometrics. 1977; 33(1):159-74.