The role of plain film radiography in the diagnosis and management of knee pain

Abstract

Background: Attempts to determine the association between the radiographic and clinical findings of knee pathology have produced conflicting results. It is also not yet known how knee radiographs influence the conservative management of patients with knee pain. Objectives: 1. To determine the association between the clinical and radiographic diagnoses of knee pain. 2. To record the consultation at which a radiograph of the knee was requested by the student or clinician and the reasons thereof. 3. To record the suspected clinical diagnoses and management of the patients prior to referral for radiographs of the knee. 4. To determine the number of incidental radiographic findings in the selected radiographs. 5. To determine any change in the clinical diagnoses and management following radiographic reporting of the selected radiographs. Method: Radiographic and clinical data from 1 January 1997 to 31 December 2010 were retrospectively collected from knee radiographs and corresponding patient files from the archives of the Chiropractic Day Clinic (CDC). Statistical analysis included the use of percentages, mean, standard deviation, range and frequency counts for the descriptive objectives. Diagnoses were categorized into specific groups and to construct two-by-two tables of absence or presence of radiographic vs. clinical diagnosis for each specific diagnosis to determine the association indicator variables were used. Results: The overall agreement between the clinical and radiographic diagnoses was 85.5%. For degenerative joint disease there was a 97.8% agreement while in Osgood Schlatter’s disease the agreement was 100%, and in chondromalacia patella the agreement was 50%. However, there was no agreement between the clinical and radiographic diagnoses for each of the other specific conditions. Degenerative changes were the most common radiographic findings. The iv majority of the knee radiographs were requested at the initial consultation and as the length of treatment increased, the frequency of radiograph requests decreased. The most common reasons for referral for radiographs were to identify degenerative changes (47.5%) and to assess for unspecified pathology (37.4%). Of the 146 patients in this study, 125 patients did not have a change in diagnosis after radiographs were obtained which means that 85.6% of the diagnoses remained the same after radiographic examination. There was a wide range of treatment modalities utilized in the management of patients with knee pain, including soft tissue therapy, electrotherapeutic modalities and manual therapy (manipulation and mobilization). The use of manual therapy increased from 67.8% prior to radiographs being taken to 82.9% after radiographs were obtained. Conclusion: Knee radiographs were over-utilized at the CDC and the findings on radiography did not have much influence on the diagnosis and the management of the patient presenting with knee pain. The majority of the clinical diagnoses were degenerative causes of knee pain.