[Is There a Correlation Between the Clinical, Radiological and Intrasurgical Findings of Osteoarthritis of the Knee? A Prospective Study on 103 Patients]

Aim: The aim of this study was to compare the different diagnostic features (symptoms, physical examination, radiographic features and intraoperative findings) of osteoarthritis of the knee before total joint replacement and consequently relate them with each other.

Method: Patients with primary osteoarthritis of the knee, who where accepted for total joint replacement in our clinic, were integrated in our study. The medical conditions were recorded by using the Womac score, the knee subscore (KS) of the Knee Society Clinical Rating System and a visual analogue scale (VAS). A physical examination was also performed. The radiological evaluation was performed by using standardised radiographs. Joint space narrowing, subchondral sclerosis, osteophytes, knee alignment and the Kellgren score were recorded. During surgery an orthopaedic specialist documented the progression of cartilage lesions using the classification of chondromalacia described by Outerbridge. The analysis of correlation was performed by using the Spearman correlation (SpK) coefficient.

Results: 103 patients were integrated in the study (mean age: 68 years, 70 women). No significant correlation could be found between the Womac score or VAS and the results of the radiological examination (SpK [Womac - Kellgren score]: - 0.04; SpK [VAS - Kellgren score]: 0.08). There was a significant correlation between the KS and the results of the radiological examination as well as the progression of the cartilage lesions, caused by the results of the physical examination documented in the KS (SpK [KS - Kellgren score]: - 0.39). The radiographic features, with the exception of subchondral sclerosis, showed a significant correlation with the degree of chondromalacia (SpK [Kellgren score - chondromalacia]: 0.43). The amount of osteophytes correlated the most with the cartilage lesions: SpK: 0.43.

Conclusion: The knee subscore appears to be an efficient method for staging the clinical progression of osteoarthritis of the knee for clinical practice as well as for clinical trials. The Womac score especially serves to record the level of pain. We were able to confirm that the presence of osteophytes is the most significant radiographic feature of osteoarthritis of the knee. The Kellgren score turned out to be a reliable method for monitoring the radiographic progression of osteoarthritis of the knee.