Crepitus is a first indication of patellofemoral osteoarthritis (and not of tibiofemoral osteoarthritis).

OBJECTIVE: The patellofemoral joint (PFJ) is important in early detection of knee osteoarthritis (OA). Little is known about the relationship between specific clinical findings and PFJ Magnetic resonance Imaging (MRI) features. The objective was to examine the relationship between (early) clinical findings and PFJ MRI features in females (45-60 years) without knee OA (PFJ or tibiofemoral joint (TFJ) OA) based on a recently suggested MRI definition. METHODS: MRIs of knees of women of a sub-study of the Rotterdam Study were scored with semi-quantitative scoring. Specific patellar tests were performed on physical examination. Current knee pain and history of patellar knee pain were reported. Binomial logistic generalized estimated equations were used to determine the association between clinical findings of OA and PFJ MRI features. All associations were adjusted for age, body mass index (BMI) and TFJ MRI features. RESULTS: In 888 women (1776 knees, mean age: 55.1 years and mean BMI: 27.0 kg/m(2)) we found significant associations between crepitus and all PFJ MRI features (Odds ratios (OR) range: 2.61-5.49). A history of patellar pain was significantly associated with almost all PFJ MRI features (ORcartilage: 1.95; ORcysts: 1.86; ORbone marrow lesions: 1.83), except for osteophytes. No significant associations were found between the clinical findings and TFJ MRI features. CONCLUSION: Crepitus and history of patellar pain are clinical findings that indicate PFJ lesions seen on MRI. These tests could help to indicate signs of PFJOA. Follow-up data needs to confirm whether these tests have an additional diagnostic value for early knee OA in PFJ or TFJ.

Development of radiological knee osteoarthritis in patients with knee complaints.

OBJECTIVES: It is currently impossible to identify which patients with knee complaints presenting to the general practitioner will develop knee osteoarthritis (OA) pathology at a later stage. This study examines the determinants for developing OA pathology on x-ray in patients with knee complaints but no radiological OA at baseline in the painful knee. METHODS: Data from the prospective Rotterdam cohort study (including subjects aged ≥55 years) were used. Analysis was performed on 623 subjects with knee complaints at baseline and their data at 6-year follow-up (T1; n=607) and at 11-year follow-up (T2; n=457). At baseline, none had radiological OA (rOA=Kellgren and Lawrence (KL) grade ≥2) in the painful joint. At follow-up, predictors for rOA were determined using multivariate ordinal logistic regression analysis. RESULTS: At T1, 8.5% of the group had developed knee rOA and, by T2, this had increased to 23%. Determinants remaining significant in the multivariate analysis were female gender (OR 1.95, 95% CI 1.15 to 3.36), other joint complaints (OR 2.22, 95% CI 1.12 to 4.35) and KL grade 1 at baseline in the painful knee joint (OR 7.14, 95% CI 4.55 to 11.1). All outcomes are adjusted for all included determinants. CONCLUSION: The best predictors of development of knee rOA are a combination of female gender, other joint complaints and KL grade 1 in the painful joint. KL grade 1 in combination with knee pain should be considered as early OA in patient management.

Impact of different descriptions of the Kellgren and Lawrence classification criteria on the diagnosis of knee osteoarthritis.

OBJECTIVES: Although the Kellgren and Lawrence (K&L) criteria for defining radiological osteoarthritis are widely used in epidemiological and clinical studies, the authors previously documented the existence of five different versions of these criteria. This study identifies the impact of the use of alternative versions of the K&L criteria and evaluates which description has the highest association with knee complaints. METHODS: Two readers scored most radiographs of the knees of participants of the Rotterdam Study with the original K&L description (90%). In addition, each alternative description was used in a random part (20%) of the radiographs. The authors calculated reproducibility of all descriptions, and compared sensitivity and specificity of the alternative descriptions for three cut-off points with the original description as reference standard (K&L≥1, K&L≥2 and K&L≥3). The authors calculated κ statistics to compare agreement between the original and alternative descriptions, and evaluated the association with knee complaints. RESULTS: The dataset comprises radiographs of knees of 3071 people. For cut-off K&L≥1 all four alternatives classified more people as having osteoarthritis than the original description; κ was low, and sensitivity and specificity were moderate to good. For cut-offs K&L≥2 and K&L≥3 there was little difference in the number of cases and κ, sensitivity and specificity were good to perfect. The original description and alternative 3 showed the strongest association with knee complaints. CONCLUSIONS: The different descriptions of the K&L criteria have impact on the classification of osteoarthritis in the lowest grade (K&L≥1). All descriptions have strengths and weaknesses. It depends on the purpose which is the best description.

Limited evidence for a protective effect of unopposed oestrogen therapy for osteoarthritis of the hip: a systematic review.

Above the age of 50 yrs, the incidence of OA rises steeply in women but less in men, suggesting an association with changes in female hormone levels in the menopause. This systematic review summarizes the evidence on the assumed association between exogenous hormone use and OA. Medline was searched up to March 2008 for articles assessing associations between OA of hand, hip or knee and menopause-related aspects. Methodological quality of the studies was assessed systematically. The results were summarized in a best-evidence synthesis. Nineteen studies on exogenous hormone use are included. Limited evidence was seen for a protective effect of unopposed oestrogen use for incidence of hip replacement/joint replacement, and a protective trend for incident radiological OA (ROA) of the knee. In prevalence studies, conflicting evidence was observed for hormone replacement therapy (HRT) use with DIP ROA and 'any joint OA', and oestrogen use with clinical knee OA. We found limited evidence for a significantly increased risk by using HRT for clinical hip OA and a significant protective effect of long-term unopposed oestrogen use for hip ROA. For all other relations studied no associations were found. Heterogeneity between the hormones used and outcome measurements made statistical data pooling impossible. The assumed relationship between the exogenous hormone use and OA was not clearly observed in this review. The relationship is perhaps too complex, or other aspects, yet to be determined, play a role in the increased incidence in women aged over 50 yrs. However, there is some evidence of a protective effect of unopposed oestrogen use for hip OA.