Association of Hip Radiograph Findings With Pain and Function in Patients Presenting With Low Back Pain.

BACKGROUND: Relationships between low back pain (LBP) and the hip in patient cohorts have been described primarily in patients with moderate to severe hip osteoarthritis (OA). Less is known about the links of LBP with hip radiographic findings of hip deformity and minimal OA.

OBJECTIVE: To describe the incidence of radiographic hip deformity or hip OA; to describe and compare spine- and hip-related pain and function in the subset of patients who were found to have radiographic hip deformity or hip OA; and to compare patients with evidence of radiographic hip deformity or hip OA to patients without hip radiographic findings.

DESIGN: Prospective cohort study with cross-sectional design.

SETTING: Tertiary university.

PATIENTS: A total of 63 patients (40 women, 23 men) with a mean age of 48.5 ± 14 years with LBP and a minimum of one positive provocative hip test.

METHODS: Hip radiographs were assessed by an independent examiner for hip OA and deformity.

MAIN OUTCOME MEASUREMENTS: Comparisons of hip and lumbar spine pain and function were completed for patients with radiographic findings of hip OA or deformity.

RESULTS: Moderate to severe hip OA was found in 12 of 60 patients (20.0%). At least one measurement of femoroacetabular impingement (FAI) was found in 14 of 60 patients (23.3%) to 33 of 45 patients (73.3%). At least one measurement of developmental hip dysplasia (DDH) was found in 7 of 60 patients (11.6%) to 11 of 63 patients (17.4%). Greater pain and reduced hip and lumbar spine function were found in the patients with moderate to severe hip OA. Patients with LBP and FAI were found to have significantly greater extremes of pain and reduced lumbar spine function.

CONCLUSION: Links between the hip and the spine affecting pain and function may be found in patients with LBP and hip deformity and before the onset of radiographic hip OA, and may be associated with hip deformity. Further investigation is needed to better understand these links and their potential impact on prognosis and treatment of LBP.

LEVEL OF EVIDENCE: II.