Unloader Research
Unloader Knee Brace Clinical Research: A synopsis of the latest research on the Unloader Knee Brace for Osteoarthritis
Presentations
Karen K Briggs, Lauren M Matheny, J Richard Steadman, Hannah Aultman
Use of an Unloader Brace for medial or lateral compartment Osteoarthritis of the Knee
Podium Presentation: 2010 Annual Meeting of the American Academy of Orthopaedic Surgeons.
Click to view the presentation abstract.
Use of an Unloader Brace for medial or lateral compartment Osteoarthritis of the Knee
Medial and lateral unloader bracing groups significantly improved. Medial group had more disability prior to brace. Lateral group showed more disability in patients with more varus alignment.
The purpose was to determine if there was a difference in factors affecting outcomes when comparing medial versus lateral unloader braces. Our hypothesis was that patients with unloader braces will have improved disability over 6-months.
Forty-six patients(17 females,29 males), with mean age of 61 years(range:48-87),were enrolled in a prospective cohort study. Patients completed WOMAC score prior to brace use, 6-weeks, 6-months. Fourteen patients were fitted with a lateral unloader and 32 with medial unloader.
There was no difference in average age between medial and lateral braced patients(both=61;p=0.9). Mean medial joint space for medial group was 2.4mm(range:0-4.2) and mean lateral joint space was 4.2mm(range:2.0-8.0) for lateral braces. Percent deviation from neutral alignment was 26%(medial) and 19%(lateral). Pre-brace pain was greater in medial group compared to lateral(8vs.5;p=0.008). Medial group also had higher pre-brace total WOMAC(34vs.23). Both groups showed significant improvement in total WOMAC from pre-brace to 6-weeks and 6 months. At 6-weeks and 6 months there was no difference in total WOMAC between groups. More improvement was seen in WOMAC for medial(12points) compared to lateral group(9points). For lateral group, 6-month total WOMAC was strongly correlated with deviation from neutral alignment(r=0.847). For medial group, pre-brace total WOMAC correlated with medial joint space(r=-0.561), as did 6-week total(r=-0.61) and 6-month total WOMAC(r=-0.496).
Few differences were seen between medial and lateral unloader bracing. Both groups significantly improved. Medial group had more disability prior to brace use and more improvement. The smaller the medial joint space, the more disability in medial group. Lateral group showed more disability in patients with more varus alignment.
Thorvaldur Ingvarsson, Jonas Franklin, Elin Hardardottir
Patients with moderate and severe knee OA do benefit from using an valgus knee brace
Podium Presentation: 2010 Annual Meeting of the American Academy of Orthopaedic Surgeons.
Click to view the presentation abstract.
Patients with moderate and severe knee OA do benefit from using an valgus knee brace
An valgus knee brace did decrease pain and improve function as shown by significant improvement in WOMAC score. It should be considered as treatment alternative in unicompartmental knee OA.
Valgus braces are designed to decrease the load on the symptomatic compartment of the OA knee by changing alignment. This should reduce pain and improve function. The purpose of this study is to document outcomes following 6 months of use of a valgus brace in a cohort of patients with knee OA.
Patients diagnosed by orthopedic surgeons, GP and rheumatologists with mild, moderate or severe unicompartmental knee OA who had prescription for valgus brace were enrolled in the study. OA was graded according to K&L from weight bearing radiographs. Patients answered WOMAC (3.1) questionnaires; before receiving the brace, after 3 weeks, 3 and 6 months. The main outcomes were the three WOMAC subscale scores (pain, stiffness, function) and the combined total WOMAC score.
82 patients participated in the study. 33 women mean age 59.7 years (40-81), 49 men average age 60.9 years (38-85). Mean BMI (SD) in men was 30.3 (±5.0) and in women 31.0 (±6.1). 5 patients discontinued using the brace because of pain during the study. 75 of the patients had radiographic medial knee OA (K&L;13 grade I, 25 grade II, 32 grade III and 11 grade IV). 7 patients had radiographic lateral knee OA (K&L;4 grade II and 3 grade III). At baseline total WOMAC score was 50 and decreased to 34 after 3 weeks. The improvement continued for six months. This is a moderate to high responsiveness according to OARSI criteria. Significant improvements compared to baseline was seen in (pain (p<0.001), stiffness (p<0.001) and function (p<0.001)). No correlation was between severity of OA (K&L) and improvement in WOMAC score. The only variable (age, gender, side, BMI, K&L, medial/lateral) which had a significant effect on WOMAC score was gender; women had a higher score.
An valgus knee brace did decrease pain and improve function as shown by significant improvement in WOMAC score for pain, stiffness and function. An valgus brace is a treatment alternative in moderate and severe unicompartmental knee OA.
Research Papers
Kirkley A, Webster-Bogaert S, Litchfield R, Macdonald S, Amendola A, MaCalden R, Fowler P
The Effect of Bracing on Varus Gonarthrosis
Journal of Bone and Joint Surgery, 81(4): 539-547, 1999.
Randomized, controlled clinical outcome study comparing the Generation II Unloader knee brace to a neoprene sleeve and to standard medical treatment, (NSAIDs or Acetaminophen, patient education and exercise), (n=119).
Results indicate that patients who have varus gonarthrosis experience a decrease in pain and improvement in disease specific quality of life with the use of an unloader brace, in addition to standard medical treatment. The Unloader brace was more effect than the neoprene sleeve.
Pollo FE, Otis JC, Backus SI, Warren RF, Wickiewicz TL
Reduction of Medial Compartment Loads with Valgus Bracing of the Osteoarthritic Knee.
American Journal of Sports Medicine, 30 (3): 414-421, 2002.Prospective cohort study measuring the load sharing capabilities of the Generation II Unloader knee brace and estimation of its effect on medial compartment force in patients with medial OA, (n=11).
Results indicate that adjustable valgus bracing (Unloader) was effective in reducing medial compartment load and subsequent pain while also improving knee function in patients with osteoarthritis.
Pollo FE, Wright, RW
Knee bracing for Unicompartmental Osteoarthritis.
Journal of the American Academy of Orthopaedic Surgeons, 14:5-11, 2006.A meta-analysis revealed that knee bracing for osteoarthritis may effectively relieve pain and improve function. Braces that reduce excessive loading on the damaged portion of the knee have been proven to be valid brace designs (Unloader brace).
Hillstrom HJ, Brower DJ, Bhimji S, McGuire J, Whitney K, Snyder H, Zonay L, Clayburne G, Sieck M, Schumacher HR
Assessment of Conservative Realignment Therapies for the Treatment of Varus Knee Osteoarthritis.
Gait & Posture, 11(2): 170-171, 2000.Prospective, randomized clinical outcomes study evaluating the efficacy, biomechanical gait analysis and changes to joint pathophysiology using the Generation II Unloader knee brace with and without in-shoe foot orthoses for the treatment of varus knee osteoarthritis (n=15).
Results indicate that valgus knee bracing, (Unloader), and neutral position foot orthoses, significantly improve lower extremity biomechanics during gait, ADLs and pain assessments in varus knee OA patients.
Horlick, SG, Loomer, RL
Valgus Knee Bracing for Medial Gonarthrosis.
Clinical Journal of Sports Medicine, 3:251-255, 1993.Randomized double cross-over study evaluating pain and function in patients with
medial compartment gonarthrosis (n=39).
Results indicate that valgus bracing, using the Generation II Unloader, can be a useful treatment modality for reducing pain in patients with medial gonarthrosis.
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