Useful ultrasonographic evaluation of the medial meniscus as a feature predicting the onset of radiographic knee osteoarthritis.

OBJECTIVE: Medial radial displacement (MRD) of the medial meniscus is a feature proving a dysfunction in the medial meniscus in osteoarthritis (OA) of the knee. MRD was measured in radiographic pre-OA knee and early osteoarthritis of the knee (early-OA) longitudinally using ultrasound (US) to investigate the characteristics involved in the onset and progression of OA. METHODS: Fifty-five patients with pain on the medial side of the knee participated in the present study. It was possible to follow-up 46 patients for 5 years, and, thus, they were divided into 32 pre-OA patients (female: 59%, mean age: 69.0 years) and 14 early-OA patients (female: 78%, mean age: 74.4 years) based on radiography at the baseline time-point. MRD was measured in standing and supine positions at baseline and after 1 and 5 years using US. MRD corrected with the skeletal size, i.e., the medial displacement index (MDI), was analyzed. The pre- and early-OA groups were divided into subgroups at 5 years: stable and OA progression groups, following the Kellgren/Lawrence classification, and ⊿MDI (gap of the MDI between the standing and supine positions) were retrospectively compared between the subgroups at baseline, 1 and 5 years. RESULTS: In the overall pre-OA group, MDI increased by 7% and 10% at 5 years in the supine and standing position, showing a significant increase (P = 0.044, 0.0147). ⊿MDI was significantly greater in the subgroup with OA progression in the pre- and early-OA groups (P = 0.02 and 0.03, respectively), and was continuously 6-7% in the pre-OA progression group, showing that the displacement rate was 2-fold or higher than in the stable group. CONCLUSION: An increase in ⊿MDI on US may be an important risk factor for the disease stage progression of OA and useful as a feature predicting the onset of radiographic knee OA.

Ultrasonographic evaluation of medial radial displacement of the medial meniscus in knee osteoarthritis.

OBJECTIVE: To evaluate medial radial displacement (MRD) of the medial meniscus in osteoarthritic (OA) and normal knees, with and without weight bearing, using ultrasonography (US), and to prospectively evaluate the time course of changes in MRD in OA knees. METHODS: The study subjects were 78 patients with OA of the knee (69% female; mean age 66.4 years) and 20 healthy, asymptomatic subjects (70% female; mean age 64.5 years) who served as a control group. The OA stage was determined according to the Kellgren/Lawrence (K/L) radiographic grading system. US measurement of MRD was performed with subjects in the supine and standing positions. With the exception of subjects who dropped out, 58 OA knees (followup rate 74%) were evaluated at baseline and ∼1 year later. RESULTS: The medial meniscus was significantly displaced radially by weight bearing in control knees (P<0.001) and in knees with K/L grades 1-3 OA (P<0.01 for each comparison). MRD in either the supine or the standing position was not significantly different between the control knees and the K/L grade 1 knees, but significant differences were noted between the control knees and K/L grade 2 or more severe OA knees (P<0.01 for each comparison). MRD of the medial meniscus had increased significantly on followup in all knees (P<0.05 for each comparison) excluding K/L grade 4 knees in the standing position. CONCLUSION: MRD of the medial meniscus increased with weight bearing and during followup. These findings suggest a close association between extraarticular displacement of the medial meniscus and progression of OA.

Recent trends in adult-onset septic arthritis of the knee and hip: retrospective analysis of patients treated during the past 50 years.

This study was a retrospective analysis of 53 adult patients with septic arthritis (SA) of the knee or hip treated during the years from 1955 to 2005 in Tottori University Hospital in Japan. Patients with postoperative infection, infection caused by trauma, and periprosthetic infection were excluded. The 50-year period between 1955 and 2005 was divided into five periods: there were 5 patients in the first decade, 9 in the second decade, 11 in the third decade, 10 in the fourth decade, and 18 in the fifth decade. All SA occurred in the knee until the fourth decade. Five cases of septic arthritis in the hip occurred in the fifth decade. In contrast to the decrease in direct infections (post intraarticular injection), hematogenous infections were observed to increase after 1986. The rate of SA caused by Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus, MRSA) had been highest during the 50 years. Infections caused by MRSA, comprising 22% of all staphylococcal infection, occurred in the fifth decade. The numbers of patients with comorbid conditions such as diabetes increased during the 50-year period. This study indicated that patients with SA have been increasing in number. Furthermore, hematogenous SA has been increasing. The increase in occurrence of SA could result from increase in opportunistic infection, occurrence of SA of the hip, and increase in MRSA infection.

Knee deformity in rheumatoid arthritis is closely correlated with generalized osteoporosis.

To examine the relationship between knee deformity and osteoporosis in women with rheumatoid arthritis (RA), bone mineral density (BMD) in the lumbar spine and distal radius was measured using dual X-ray absorptiometry, and knee deformity (valgus or varus deformity) was measured using plain radiograms in 55 women with RA. Associations between knee deformity and BMD, disease related variables, including RA stage, RA duration, age, cumulative doses of administered glucocorticosteroids, body mass index, or postmenopausal period were evaluated. Cut-off values of the BMD defining RA patients with knee deformity were very close to the BMD value corresponding to 70% of young adult mean in the lumbar spine and distal radius. The femorotibial alignment was significantly correlated with age and deformity of the proximal tibia. Deformity of the proximal tibia was negatively correlated with the radial BMD and lumbar BMD. Deformity of the proximal tibia showed a significant difference between the groups of less than 5 years after menopause and the group of 5-10 years after menopause. We concluded that knee deformity in RA derived from deformity of the proximal tibia, and it was closely correlated with generalized osteoporosis.