Newswise — SAN DIEGO — Use of a patellofemoral knee brace can improve pain symptoms and bone marrow lesions in patients with a type of osteoarthritis of the knee, according to new research findings presented this week at the American College of Rheumatology Annual Meeting in San Diego.
Osteoarthritis, or OA as it is commonly called, is the most common joint disease affecting middle-age and older people. It is characterized by progressive damage to the joint cartilage—the cushioning material at the end of long bones—and causes changes in the structures around the joint. These changes can include fluid accumulation, bony overgrowth, and loosening and weakness of muscles and tendons, all of which may limit movement and cause pain and swelling.
Knee osteoarthritis is a common form of osteoarthritis and is caused by cartilage breakdown in the knee joint. Factors that increase the risk of knee osteoarthritis include being overweight, age, injury or stress to the joints, and family history.
Researchers at the University of Manchester, the University of Warwick in the United Kingdom and Boston University studied the effects of six weeks of patellofemoral knee brace use in 126 OA patients between the ages of 40 and 70. The patients included in the study all had KL grade two or three patellofemoral OA, and their average pain score at the beginning of the study was 64.6. Ninety patients who had MRI scans at the beginning of the study showed patellofemoral bone marrow lesions – damage that is caused in part by focal stress on this joint. Patients in the bracing group wore a BIOSKIN patellar tracking Q brace for an average of 7.3 hours a day; the patients in the control group wore no brace.
The study’s aim was to measure the effects of a patellofemoral brace on knee pain and bone marrow lesions, as these braces have been shown to increase contact area in the joint, decreasing focal stress and possibly correcting joint malalignment.
Patients were given both questionnaires to measure symptoms like pain and tenderness, and MRI scans to measure their bone marrow lesions at the beginning and end of the six-week period. The patients who wore the knee brace showed significant reduction in patellofemoral joint pain, as well as a decrease in the volume of bone marrow lesions in their patellofemoral joint. However, the brace did not improve bone marrow lesions in the tibiofemoral joint. The researchers concluded that bracing is effective at reducing both pain and lesions in patellofemoral osteoarthritis, and that further trials of OA treatments could use bone marrow lesions as a way to measure outcomes and efficacy.
“This research is important for two reasons,” explains William F. Harvey, MD, MSc; assistant professor of medicine; clinical director, Division of Rheumatology; Tufts Medical Center; and a researcher who has collaborated with the study’s lead investigator on a previous clinical trial of a patellofemoral brace. “There is a desperate need for effective non-pharmacologic treatments that avoid all the potential side effects of treatment with medications. Additionally, this treatment is one of only a very few that have demonstrated the ability to improve both pain and the underlying structure of the joint in persons with knee osteoarthritis.”
Patients should talk to their rheumatologists to determine their best course of treatment.
The American College of Rheumatology is an international professional medical society that represents more than 9,000 rheumatologists and rheumatology health professionals around the world. Its mission is to advance rheumatology. The ACR/ARHP Annual Meeting is the premier meeting in rheumatology. For more information about the meeting, visit http://www.acrannualmeeting.org/ or join the conversation on Twitter by using the official hashtag: #ACR13
Editor’s Notes: Dr. Felson will present this research during the ACR Annual Meeting at the San Diego Convention Center at Noon on Monday, October 28 in Room 6 A. Dr. Felson will be available for media questions and briefing at 1:30 PM Monday, October 28 in the on-site press conference room, 27 AB.
Abstract Number: 1694
A Randomised Trial Of A Brace For Patellofemoral Osteoarthritis Targeting Knee Pain and BoneMarrow Lesions
David T. Felson1, Matthew J. Parkes1, Andrew D. Gait1, Elizabeth J. Marjanovic1, Mark Lunt2, Charles E. Hutchinson3, Laura Forsythe1, Timothy F. Cootes1 and Michael Callaghan1, 1University of Manchester, Manchester, United Kingdom, 2Arthritis Research UK Epidemiology Unit, University of Manchester, Manchester, United Kingdom, 3University of Warwick, Coventry, United Kingdom
Background/Purpose: Patellofemoral (PF) braces have been shown to increase contract area in this joint, decreasing focal stress and may also correct patellar malalignment. Bone marrow lesions (BMLs) are lesions in the subchondral bone of osteoarthritis (OA) knees on MRI that are caused in part by focal stress in the joint. Because BML size correlates with knee pain severity, because they predict structural progression and because recent evidence suggests, unlike cartilage, that their volumes fluctuate substantially in as little as 6 weeks, BML's may be a good outcome to test short term structure modification in OA trials. We performed a trial testing the efficacy of the BIOSKIN patellar tracking Q brace (Ossur, inc).
Methods: Eligible subjects had to have pain daily of >=40/100 for the last 3 months during a PF activity and on examination had tenderness over patellar facet or a positive patellar compression test. X-rays had to show KL grade 2 or 3 PFOA which was worse than tibiofemoral disease. At baseline, subjects were randomly allocated to immediate or 6 weeks provision of the brace; the trial lasted 6 weeks. Subjects with other forms of arthritis were excluded as were those ineligible for MRIs or with impaired renal function. Gadolinium MRIs were acquired on a 1.5 T MRI at baseline, and at 6 weeks. Postgadolinium fat suppressed sagittal and PD weighted axial images were used for BML's which were manually segmented (blinded to sequence and to treatment) at all time points. The primary symptom outcome was the change in pain at 6 weeks (0 – 100 VAS scale) during the PF painful activity in the more symptomatic knee and the primary structural outcome was BML volume in the PF joint of that knee (patella and trochlea). We also examined tibiofemoral (TF) BML volumes as a control untreated region. Analyses used multiple linear regression with an ITT approach.
Results: We randomised 126 subjects age 40-70 years (mean age 55.5 years (SD 7.5 years); 72 females (57.1%). Mean pain score at baseline was 64.6. Ninety of the 125 with MRI scans (72%) had PF BML's at baseline. Subjects wore the brace for a mean of 7.4 hrs/day. Six subjects withdrew during the RCT (an additional 2 did not attend one session, and therefore had only one MRI). Compared with the control group, the brace group had both a significant reduction in PF-related knee pain and a decrease in the volume of BML's in the PF but not in the TF joint (see Table).
Conclusion: A patellofemoral brace is efficacious for treatment of PF OA reducing both symptoms and BML volumes in the targeted compartment. BML's may be a responsive outcome measure in OA trials.
Disclosures: D. T. Felson, None.
M. J. Parkes, None.
A. D. Gait, None.
E. J. Marjanovic, None.
M. Lunt, None.
C. E. Hutchinson, None.
L. Forsythe, None. T. F. Cootes, None. M. Callaghan, None.