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Purpose of review: The biomechanical aspects of gait and the impact of alignment have been recognized as important in the development and progression of knee osteoarthritis. Improving malalignment and altering the dynamic forces on the involved compartment of the knee during gait have the potential to improve the symptoms of knee osteoarthritis. This review examines the use of foot orthoses and knee braces to change the biomechanical forces on the knee joint and to reduce pain and improve function in patients with existing symptomatic knee osteoarthritis.
Recent findings: Malalignment has been shown to have an impact on the development and progression of knee osteoarthritis. Patients with medial compartment knee osteoarthritis who have a visible varus thrust will also progress at a more rapid rate than patients without a varus thrust. Lateral wedge foot orthoses have been shown in biomechanical studies and clinical studies to reduce the load on the medial compartment and improve the symptoms of medial compartment knee osteoarthritis. Knee braces that stabilize the knee joint and provide a valgus stress have been shown to improve pain and function in patients with medial compartment knee osteoarthritis.
Summary: The development of symptomatic knee osteoarthritis and the progression of joint space loss is in part a biomechanical process. To improve patients' function and possibly reduce disease progression, a biomechanical approach should be included in the treatment plan for patients with knee osteoarthritis. Foot orthoses and knee braces have been shown in selected patients to have a role in the management of unicompartmental knee osteoarthritis.
Is anyone actually using lateral foot wedgeing for knee OA? (I know Kevin has written a Precision Intricast Newsletter on the topic)
__________________
Craig Payne
Department of Podiatry
La Trobe University
Melbourne, Australia http://www.latrobe.edu.au/podiatry
__________________________________________________ ___________________________________ God put me on this earth to accomplish a certain number of things - right now I am so far behind, I will never die.
The views expressed above are those of the author and not that of La Trobe University This is where I am, where are you?
Last edited by Admin : 15th December 2007 at 08:52 PM.
Reason: deleted link no longer working
Osteoarthritis of the knee is a common condition that can cause considerable pain and disability. Various forms of lateral wedging may be effective in the treatment of medial compartment osteoarthritis, but it is not known whether incorporating a lateral wedge into a custom-molded foot orthosis will achieve similar results. Therefore, 30 subjects (21 men and 9 women) aged 29 to 77 years (mean ± SD, 58.1 ± 11.6 years) with radiographically confirmed medial compartment knee osteoarthritis were issued custom-molded foot orthoses with a 5° lateral heel wedge. Pain levels were recorded using a 100-mm visual analog pain scale on the date of issue of the orthoses (baseline) and again 3 and 6 weeks later. Mean ± SD pain levels were significantly reduced at 3 weeks (34 ± 22 mm) and 6 weeks (23 ± 22 mm) versus baseline (69 ± 19 mm) (F2 = 39.57). The degree of pain reduction was greater in patients with less severe osteoarthritis. At 6 weeks, all subjects had achieved at least some reduction in pain, and 28 reported that their orthoses were comfortable. This preliminary study indicates that laterally wedged foot orthoses may be beneficial in the treatment of mild-to-moderate osteoarthritis of the medial compartment of the knee. Further investigations using a larger sample, longer follow-up, and a no-treatment control group seem warranted.
[quote=Craig Payne]Is anyone actually using lateral foot wedgeing for knee OA? (I know Kevin has written a Precision Intricast Newsletter on the topic)
QUOTE]
I have successfully used lateral (i.e. valgus) wedging for lateral compartment knee osteoarthritis (OA) and medial (i.e. varus) wedging for medial compartment knee OA for about 15 or more years in my patients. Actually, when you go back in the orthopedic literature, this technique has been used for quite a few years, but I was never taught about it in podiatry school or my Biomechanics Fellowship at CCPM. I have found both varus and valgus wedging extremely effective in patients with mild to moderate thinning of the articular cartilage in the medial and/or lateral compartments of the knee.
As Craig noted, I have proposed a mechanical model for the action of valgus wedging in insoles and foot orthoses for medial knee OA in a couple of recently published Precision Intricast Newsletters: "Lateral Heel Skive Orthosis Technique" in September 2004 and "Foot Orthoses for Medial Compartment Osteoarthritis of the Knee" in October 2004. We hope to put these out for general publication as a 20 year collection of Precision Intricast Newsletters in a couple of years.
In addition, Eric Fuller and I describe a similar model for the mechanical action of valgus wedges for medial knee OA in our chapter "Subtalar Joint Equilibrium and Tissue Stress Approach to Biomechanical Therapy of the Foot and Lower Extremity" in a book edited by Stephen Albert, DPM that should be published within the next six months.
One other related item is that Bart VanGheluwe, Friso Hagman and I will have a paper published in JAPMA in the next six months that on the mechanical effects of simulated genu valgum and genu varum on STJ moments during gait (Van Gheluwe B, Kirby KA, Hagman F: Effects of simulated genu valgum and genu varum on ground reaction forces and subtalar joint function in gait. JAPMA, Accepted for publication.) This paper explores STJ moments and GRF variablity with different gait patterns in normal subjects but the model that we generated and discussed in this paper may have application in discussing/predicting moments and forces within the knee joint.
The discussion of center of pressure (CoP) location on the plantar foot relative to the angle subtended by the hip joint center, knee joint center and the CoP location is critical to understanding the frontal plane moments generated at the knee during weightbearing activities. By far, the best discussion of these hip and knee moments and the pathomechanics behind medial and lateral knee OA is from a book that is now out of print but is one of my favorite books on knee mechanics by Maquet (Maquet, Paul G.J.: Biomechanics of the Knee. Springer-Verlag, New York, 1984).
This is a fascinating and important subject for podiatrists to explore since we routinely treat knee pathology with in-shoe inserts by alteration of the location, magnitude and temporal patterns of CoP on the plantar foot with these inserts.
__________________
Sincerely,
Kevin
**************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
Thinking about and working on a hypothesis that we may have some data on soon.
A high abductor moment at the knee is probably one of he most important risk factors for medial knee OA..... a lateral foot wedge is one of the more effective ways to reduce that abductor moment ---- problem is, it does not always do so.... so what is being considered is that it might have something to do with STJ ROM. If there is a range of eversion at STJ --> wedge pronates foot and internally rotates knee --> no change in abductor moment. If there is no range of eversion at STJ --> wedge can not pronate foot --> decrease in abductor moment at knee. It is surprising how many people in the age group with knee OA have no or very little eversion from their RCSP.
__________________
Craig Payne
Department of Podiatry
La Trobe University
Melbourne, Australia http://www.latrobe.edu.au/podiatry
__________________________________________________ ___________________________________ God put me on this earth to accomplish a certain number of things - right now I am so far behind, I will never die.
The views expressed above are those of the author and not that of La Trobe University This is where I am, where are you?
Last edited by Craig Payne : 13th August 2005 at 08:48 PM.
Thinking about and working on a hypothesis that we may have some data on soon.
A high abductor moment at the knee is probably one of he most important risk factors for medial knee OA..... a lateral foot wedge is one of the more effective ways to reduce that abductor moment ---- problem is, it does not always do so.... so what is being consideed is that to might have something to do with STJ ROM. If there is a range of eversion at STJ --> wedge pronates foot and internally rotates knee --> no change in abductor moment. If there is no range of eversion at STJ --> wedge can no pronate foot --> decrease in abductor moment at knee. It is surprising how many people in the age group with knee OA have no or very little eversion from there RCSP.
Let me clarify what Craig wrote above so that there isn't any confusion for those of you that are following along. We must be careful when we speak of moments at a joint and be certain to distinguish if we are speaking of an internal moment or an external moment. If there is a large magnitude of external knee adduction moment then medial knee OA will be more likely to occur since the internal knee abduction moment will be of greater magnitude.
A good way to explain whether the knee pain will be relieved by a valgus wedge or not is if the center of pressure (CoP) is shifted laterally or not. In the foot that pronates the CoP will not shift as far laterally with application of a valgus wedge as the foot that does not pronate. Also, it doesn't surprise me how many patients have maximally pronated subtalar joints in relaxed bipedal stance....I see them all day long in my clinic!
__________________
Sincerely,
Kevin
**************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
I have been using lateral wedging / lateral heel skives and similar for many years to treat medial knee compartment OA.
Typically we all see a genu/tibial varum with this deformity, and I often wonder about the chicken and egg scenario to explain it. My gut tells me these (mostly) men had excessive tibial varum first, which compressed the medial compartment over time, then created a more pronounced genu varum...
I find this approach very successful, the aim being to transfer CoP forces from the 'damaged' to the relatively 'undamaged' compartment. How you prove this is nigh on impossible, except in a theoretical sense. You would know better than I about such things.
My usual caveat is we are going to sacrifice 'ideal' foot function to provide symptomatic relief at the knee, also that it wil be a stop-gap measure to delay need for high tibial osteotomy or TKR.
My usual caveat is we are going to sacrifice 'ideal' foot function to provide symptomatic relief at the knee, also that it wil be a stop-gap measure to delay need for high tibial osteotomy or TKR.
None of the studies on lateral wedging reported in the literature and none that I have been involved with has there been reported any foot symptoms developing as the result of the lateral wedge pronating the foot more.
__________________
Craig Payne
Department of Podiatry
La Trobe University
Melbourne, Australia http://www.latrobe.edu.au/podiatry
__________________________________________________ ___________________________________ God put me on this earth to accomplish a certain number of things - right now I am so far behind, I will never die.
The views expressed above are those of the author and not that of La Trobe University This is where I am, where are you?
I have noted the same in my readings, particularly the Japanese ortho literature...
However, I still throw this one out there to cover my derriere, for if they shop around to another podiatrist who notes that I am attempting to 'pronate' the STJ - I have no doubt that some would get up in arms about the concept and hoodwink the patient into believing that it is an inappropriate course of action.
Its funny that we (the podiatry profession) have no hesitation whatsoever in supinating a foot ad nauseum, but when you do the opposite some podiatrists consider it grand herecy!
I think we may only be teaching our students one half of the pie sometimes...
I just saw a patientwith medial knee pain and lower leg pain.I applied a lateral wedge to his shoes.I will tell everyone how he made out.I had no idea that these can help,but I know now.As Drs.Kirby& Payne said ,a wedge can shift the center of gravity laterally and this can alleviate pain. :p
Patient responses seem to vary...I have often tried it in my rehab(70+ age group usually ) work...and now I tend to say .." let's see what happens....you will be the best judge of how you feel after a week or three...." I tend to agree with the idea about long term degen often contributed to by greater tib varum...as previously said and I tend to think the respnse you get to lateral wedging depends on how bad it already is and what there is left to work with.
Regards Phill Carter
I have a note of how Yasuda and Sasaki (1987) used a wedged board, load transducers, and x-rays to demonstrate how a lateral tilt in the weightbearing foot decreased excessive loading on the medial compartment of the knee. I assume that anyone doing work on this subject will have read this paper?
For those who haven't, its a nice study :) , but the cohort is a little small (n=10).
The full ref is
Yasuda k, Sasaki T. The Mechanics of Treatment of the Osteoarthritic Knee with a Wedged Insole. Clin Orth and Related Research. . No 215, 162-172, 1987.
I have been using lateral wedging / lateral heel skives and similar for many years to treat medial knee compartment OA.
Typically we all see a genu/tibial varum with this deformity, and I often wonder about the chicken and egg scenario to explain it. My gut tells me these (mostly) men had excessive tibial varum first, which compressed the medial compartment over time, then created a more pronounced genu varum...
I find this approach very successful, the aim being to transfer CoP forces from the 'damaged' to the relatively 'undamaged' compartment. How you prove this is nigh on impossible, except in a theoretical sense. You would know better than I about such things.
My usual caveat is we are going to sacrifice 'ideal' foot function to provide symptomatic relief at the knee, also that it wil be a stop-gap measure to delay need for high tibial osteotomy or TKR.
A very nice mechanical explanation, including different types of stress analysis, of how tibial/genu varum deformity causes medial compartment osteoarthritis (OA) was done by Maquet over 20 years ago (Maquet, Paul G.J.: Biomechanics of the Knee. Springer-Verlag, New York, 1984). In one analysis technique, he made photoelastic models of the knee using plexiglass and then observed them under various loading conditions while illuminated by white polarized light. The resultant light and dark lines within the plastic model are indicative of the magnitude and direction of stress within the knee.
Maquet also calculated loads on the knee using graphic modeling techniques and developed explanations for the cause of medial knee OA with a tibial/genu varum deformity. I use these models in my lectures on varus and valgus wedging for knee OA to this day.
Currently, within the international biomechanics literature, finite element analysis techniques have been extensively used in designing knee implants and this more advanced modeling technique will certainly be the wave of the future in predicting knee joint loading forces.
These techniques are not just theoretical. They are scientifically based mechanical analysis techniques used every day by engineers worldwide to design buildings, boats, bridges, automobile engines, etc. The future of advances in podiatric biomechanics will be based on the understanding of these modeling techniques that will ultimately allow podiatrists to better understand the most efficient methods by which to reduce the abnormal stresses on the injured structural components of the foot and lower extemity with in-shoe and/or external shoe modifications, or other treatment techniques.
__________________
Sincerely,
Kevin
**************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
Feet insoles and knee osteoarthritis: evaluation of biomechanical and clinical effects from a literature review.
Ann Readapt Med Phys. 2005 Jun 13; [Epub ahead of print] [Article in French]
Gelis A, Coudeyre E, Aboukrat P, Cros P, Herisson C, Pelissier J.
Quote:
Objective. - To determine the biomechanical and clinical effectiveness of foot insoles in patients with knee osteoarthritis. Materials and methods. - A systematic review of the literature (Medline, Pascal and Embase) using the MESH words knee, and insole and plantar orthosis for the biomechanical part and osteoarthritis, and insole and plantar orthosis for the clinical part. Clinical studies were classified by 2 independent readers using the Jadad scale. Results. - Two biomechanical theories were found: the adduction moment theory, which explains the effect of heel wedging, and articular chain theory, which explains the effect of lateral wedged insoles. The clinical effect was explained more by an anti-algesic effect than an anatomic or functional effect: the treated group consumed fewer nonsteroidal anti-inflammatory drugs than the placebo group for up to 2-years of treatment. Evidence is lacking because of methodological weakness and few clinical trials. The information on side effects is limited. Discussion. - Laterally wedged foot insoles are proposed for the treatment of knee medial compartment osteoarthritis. The clinical effect is probably limited, but the treatment may reduce the digestive and renal side effects of prolonged use of nonsteroidal anti-inflammatory drugs. Foot insoles could be recommended in clinical practice despite the lack of evidence in comparing the effectiveness of other therapeutics in knee osteoarthritis. Conclusion. - Use of foot insoles is a nonpharmacologic treatment of osteoarthritis of the knee medial compartment.
The collected data was interested in that the films showed no appreciable change, but their comfort was almost immediate. 4/7 patients I still see for their lateral wedge orthotics. A couple of them are very active, but avoid any impact actvities. They find the orthotics very comfortable with no foot problems. I use this method of treatment very often with good success.
Freeman
[quote=Kevin Kirby]I have successfully used lateral (i.e. valgus) wedging for lateral compartment knee osteoarthritis (OA) and medial (i.e. varus) wedging for medial compartment knee OA for about 15 or more years in my patients. [quote]
Valgus wedging will increase compressive forces in the lateral compartment.
Varus wedging will increase compressive forces in the medial compartment.
Have you got this the right way? Or am I reading it the wrong way?
Patient responses seem to vary...I have often tried it in my rehab(70+ age group usually ) work...and now I tend to say .." let's see what happens....you will be the best judge of how you feel after a week or three...." I tend to agree with the idea about long term degen often contributed to by greater tib varum...as previously said and I tend to think the respnse you get to lateral wedging depends on how bad it already is and what there is left to work with.
Regards Phill Carter
No, the reason why the response varies is this. We all seem to think that medial knee pain is caused by medial joint compression/OA alone. Truth be known it is not. Medial knee pain can be caused by a completely 'opposite' pathology...that being MCL tensile pathology.
Applying a valgus wedge will "open up" the medial compartment. The OA will love it; the MCL will hate it. Hinman can't understand why 33% of "medial knee joint OA's" were worse after lateral wedging. I say that these 33% were suffering clinical medial ligament tensile issues over and above any radiographic and/or rheumatological diagnoses of OA.
[quote=Atlas][quote=Kevin Kirby]I have successfully used lateral (i.e. valgus) wedging for lateral compartment knee osteoarthritis (OA) and medial (i.e. varus) wedging for medial compartment knee OA for about 15 or more years in my patients.
Quote:
Valgus wedging will increase compressive forces in the lateral compartment.
Varus wedging will increase compressive forces in the medial compartment.
Have you got this the right way? Or am I reading it the wrong way?
OOPS! Valgus wedging should be used for medial knee OA and varus wedging should be used for lateral knee OA. Thanks for pointing out my typo!
__________________
Sincerely,
Kevin
**************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
the varus deformity of medial compartment osteoarthritis
The varus deformity that accompanies medial compartment osteoarthritis (MCOA) develops as a result of the disease and is correctable in sitting. It is not the cause. The fact that the lesion of MCOA is so localised within one compartment of the knee within a tricompartmental joint is a pointer to the fact that it is the result of a biomechanical failure not a systemic one or a genetic problem of cartilage. There is some evidence that the development of MCOA is associated with the pronated foot, the tibia being held in internal rotation for too long while the femur rotates externally in late midstance while the knee is extending leading to increased torsion and tissue damage. The rate of repair of tissue diminishes with age and eventually in the elderly this leads to tissue breakdown. There is a link between MCOA and obesity and there is also a link between increased pronation and obesity. If there is an association between the over pronated foot and MCOA it seems unlikely that a lateral wedge which will increase this is likely to lead to any long term improvement. A recent systematic review of lateral wedges has indicated that there really is no evidence that it has any long term positive effects. Also, it must be important to examine the foot before applying a treatment which causes a change in the foot dynamics. An already pronated foot leads to problems of the whole musculo skeletal system - is it ethical to increase this risk. It must surely be relevant to examine the foot carefully before applying any wedging. Medial wedging might seem to be the answer to a pronated foot but because of the varus deformity of the knee in MCOA this may increase the pain - that does not lead to the conclusion that lateral wedging is the answer. Has anyone examined the long term results of the use of lateral wedges ?
Thank you for your note. I have been doing lateral (valgus) wedging for 25 years witha a variety of orthopaedic surgeons in Halifax Nova Scotia. I first started it on a research project wityh Dr. Bill Stanish. Xrays confirming medial OA on remarkable tib varum patients with significant pain showed no change on the joint line from the uncorrected standing films to the medially wedged(valgus) films. However instant relief was experienced in 80% of those patients. I am still treating some of those same patients, and buckets more very successfully. There is a compromise to a certain degree becasue I am medially wedging an already pronated foot, however it seems that bigger pain in medial joint line OA which untreated is quite unbearable. I have treated medial OA patients with memdial/varus wedging as per some MD's requests and more often than not they return to have it reversed.
The varus deformity that accompanies medial compartment osteoarthritis (MCOA) develops as a result of the disease and is correctable in sitting. It is not the cause. The fact that the lesion of MCOA is so localised within one compartment of the knee within a tricompartmental joint is a pointer to the fact that it is the result of a biomechanical failure not a systemic one or a genetic problem of cartilage. There is some evidence that the development of MCOA is associated with the pronated foot, the tibia being held in internal rotation for too long while the femur rotates externally in late midstance while the knee is extending leading to increased torsion and tissue damage.
What evidence is that? The evidence that I have seen is that it an increase in the adduction moment is the risk factor and NOT the alignment.
Quote:
There is a link between MCOA and obesity and there is also a link between increased pronation and obesity. If there is an association between the over pronated foot and MCOA
You can't make that leap to come to a conclusion.
Quote:
it seems unlikely that a lateral wedge which will increase this is likely to lead to any long term improvement. A recent systematic review of lateral wedges has indicated that there really is no evidence that it has any long term positive effects.
That recent systematic review did not include all the recent studies, most of which are still in press. It did also not break the studies down into OA severity and the effects of lateral wedges (grade does matter). It did also not break the studies down into the type of wedge used (length of wedge does matter)
Quote:
Also, it must be important to examine the foot before applying a treatment which causes a change in the foot dynamics. An already pronated foot leads to problems of the whole musculo skeletal system - is it ethical to increase this risk.
What evidence do you have a that a pronated foot is a risk factor for anything? Of the ~25 studies that I have seen on risk factors of lower extremity problems, a pronated foot was only shown to be a minor risk factor in one of them.
Quote:
Has anyone examined the long term results of the use of lateral wedges ?
In every study done on lateral wedging for knee OA (and we 24 months into ours with >100 subjects recruited so far), not one of them has reported any subject getting any other symptoms or any foot pain. Its just another of those podiatric myths that pronating a foot more is a problem (the forces associated with pronation are a problem, but not the motion or position of pronation). I thought we had moved on from that mindset.
__________________
Craig Payne
Department of Podiatry
La Trobe University
Melbourne, Australia http://www.latrobe.edu.au/podiatry
__________________________________________________ ___________________________________ God put me on this earth to accomplish a certain number of things - right now I am so far behind, I will never die.
The views expressed above are those of the author and not that of La Trobe University This is where I am, where are you?
Last edited by Craig Payne : 8th November 2006 at 10:34 PM.
Reason: changed abduction to adduction
Patients I have seen have ranged from obese to emaciated runners of which I am one. The outcomes are very good. Again I will emphasize that medial OA c an be excruciating and disabling, not that foot pain isn't...but weighing out the bigger picture in terms of nonsurgical relief I have tended to use a heel to forefoot valgus wedge.
I will aslo say that if I am treating a patient with a foot problem and no medial knee pain who has remakable tib varum I make sure they tell me if they get any medial knee pain with the orthotics...I am very careful to treat the foot with as little as I can get away with, as far as medial posting is concerned so that I do not create problems up at the knee
I do know some practicioners who cannot bring themselves to placing a valgus wedge or post on any patient for any rerason because they "cannot bring themselves to willfully pronate a foot".
The last comment in my ranting/raving here, is that when I began to help my colleague Dr. Stanish, I did not understand fully all about why I was doing what he was asking me to do when he asked me to apply lateral (valgus) wedging or posting). It has worked well, and I have learned by faith, moreso than my own understanding.
Dear Kathleen,I have tended to use a heel to forefoot valgus wedge.
Thats the key - if you look at the literature, the studies that showed no change in abductor moments at the knee used a shorter wedge (thats if you can actually work out from the publication what they actually used as a "wedge". We putting finishing touches to manuscript for submission on "Length Does Matter" (though we suspect that the journal editor will want to change the title ) - we tested several different length wedges - only the full length reduced knee abductor moment (and abductor moment increase is numero uno risk factor for medial knee OA).
__________________
Craig Payne
Department of Podiatry
La Trobe University
Melbourne, Australia http://www.latrobe.edu.au/podiatry
__________________________________________________ ___________________________________ God put me on this earth to accomplish a certain number of things - right now I am so far behind, I will never die.
The views expressed above are those of the author and not that of La Trobe University This is where I am, where are you?
The Cochrane Review on this topic, is also worth being aware of:
Cochrane Database Syst Rev. 2005 Jan 25;(1):CD004020.
Braces and orthoses for treating osteoarthritis of the knee.
Brouwer RW, Jakma TS, Verhagen AP, Verhaar JA, Bierma-Zeinstra SM.
Orthopaedic surgery, Erasmus Medical Centre Rotterdam, Dr. Molewaterplein 40, Rotterdam, Netherlands, 3015 GD. r.w.brouwer@mzh.nl
BACKGROUND: Patients with osteoarthritis of the knee can be treated with a brace or orthosis (shoe insole). The main purpose of these aids is to reduce pain, improve physical function and, possibly, to slow disease progression. OBJECTIVES: To assess the effectiveness of a brace or orthosis in the treatment of osteoarthritis of the knee. SEARCH STRATEGY: We searched Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE (Current contents, Health STAR) up to October 2002. The reference lists of the publications in the identified trials were also screened. SELECTION CRITERIA: Extracted studies were included in the final analysis if they met the pre-defined inclusion criteria: 1) a randomised controlled clinical trial or a controlled clinical trial, 2) all patients had osteoarthritis of the knee, 3) the intervention in one of the studied groups was a brace or an orthosis. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected the trials and assessed the methodological quality using the Delphi-list and one additional question about care programs. Three reviewers independently extracted the data on the intervention, type of outcome measures, follow-up, loss to follow-up, and results, using a pre-tested standardized form. Study authors were contacted for additional information. MAIN RESULTS: Four trials involving a total of 444 people were included in this review. One study investigated a knee brace and three studies examined different types of orthoses for medial compartment osteoarthritis of the knee. Two studies were of high methodological quality while the other two studies were low. Notably, the randomisation and the blinding procedures were either insufficient or not described. The follow-up period (six weeks to six months) was too short to demonstrate long-term results. Pooling was difficult primarily due to the heterogeneity of the data and the way the information was presented.The pain, stiffness and physical function (WOMAC and MACTAR) scores of a brace group showed greater improvement at six months compared with a neoprene sleeve group, which showed greater improvement compared with a control group.The numbers of days of non-steroidal anti-inflammatory drug (NSAID) intake decreased significantly (relative percentage difference 23.9%) compared with baseline in a group with laterally wedged insoles,and remained unchanged in the neutrally wedged group. Patient compliance with the laterally wedged insole was significantly better compared with the neutrally wedged insole. In one study, the Visual Analogue Pain (VAS) pain score was significantly decreased from baseline in a strapped insole group (RPD - 24%), but not in the traditional lateral wedge group, but this strapped insole showed more adverse effects (popliteal pain, low back pain, and foot sole pain) compared with the traditional lateral wedge insole. Pain during bed rest, after getting up, after getting up from seated position and walking distance was significantly improved in a subtalar strapped group compared with baseline, and no improvement was found in a sock type group. No studies were found that assessed the effectiveness of a brace or orthosis to treat lateral compartment osteoarthritis or general osteoarthritis of the knee, or that compared a knee brace with a wedge insole, or that compared a brace or orthosis with operative treatment. AUTHORS' CONCLUSIONS: Based on one brace study we conclude there is limited evidence that: a brace has additional beneficial effect (WOMAC, MACTAR, function tests) for knee osteoarthritis compared with medical treatment alone.(Silver) a sleeve has additional beneficial effect (WOMAC, function tests) for knee osteoarthritis compared with medical treatment alone.(Silver) a brace is more effective (WOMAC, function tests) than a neoprene sleeve.(Silver) Based on 3 orthoses studies, of which 2 were high quality, (n=2) we conclude there is limited evidence that: a laterally wedged insole decreases NSAID intake compared with a neutral insole. (Silver) patient compliance is better in the laterally wedged insole compared with a neutral insole. (Silver) a strapped insole has more adverse effects than a lateral wedge insole. (Silver).
I have also found over the past 20 years of using valgus wedges for medial knee osteo-arthritis that the full length wedge is most effective for the patient. One of the methods I use in the office for a "quick and dirty test" is to take the sockliner out of the shoe and then place one to two pieces of 1/8" (3 mm) adhesive felt in the shape of a valgus wedge to the sulcus (see illustration below). This works quite well. If necessary, a full length orthosis is prescribed with lateral heel skive and valgus forefoot extension.
These valgus wedges cause an increase in magnitude of external knee abduction moment (i.e. increase in magnitude of internal knee adduction moment) which will lessen the medial compartmental pressure in the knee and increase the lateral compartment pressure in the knee. I believe that the reason that forefoot valgus wedging is important in treating this problem is that the forefoot is more laterally positioned to the long axis of tibia than the heel is. Therefore, an increase in GRF on lateral forefoot (with a valgus forefoot wedge) has more ability to generate increased knee abduction moments than increases in GRF on the lateral heel (with a valgus heel wedge). This can be easily demonstrated by modelling the foot and knee with the apparent forces and moments applied. I presented these ideas previously in my October 2004 Precision Intricast Newsletter "Foot Orthoses for Medial Compartment Osteoarthritis of the Knee."
__________________
Sincerely,
Kevin
**************************************************
Kevin A. Kirby, DPM
Adjunct Associate Professor
Department of Applied Biomechanics
California School of Podiatric Medicine at Samuel Merritt College
Working in an orthopaedic hospital I have had the opportunity to look at lots of feet - not to treat them but to observe. The differences in foot type of the patients who were about to have hip replacements and those who were about to have an Oxford unicompartmental knee replacement for end stage arthritis was marked and I published a paper on this in Foot and Ankle international. The hip patients' feet were more homogenous. The OA of those patients with medial compartment problems was often secondary to earlier knee surgery, occupation and it appeared to be excess weight gain. The differences in their feet is what made me doubtful about using lateral wedges indiscriminately. None of the studies seemed concerned about the foot they were applying the wedge to - I thought this should be an initial consideration. Recently I have had the opportunity to review patients 5 years after hip replacement. Some have had leg length discrepancy - in the literature this has been demonstrated to have no ill effects but many of these patients are complaining of severe back ache. This is a topic I hope to investigate - the long term effects have not been fully investigated because no one really cares a few years down the line. But I think that very small changes around the feet can have, over time, major effects further up the musculo skeletal system. Also the knee abduction moment is part of normal gait, there is more pressure in the medial compartment in normal gait that is apparent from the anatomy of the knee. What pronated and supinated feet do is upset normal gait patterns - supinated feet inhibit internal rotation of the tibia, knee flexion and internal rotation of the hip whereas pronated feet inhibit external rotation of the tibia, knee extension and external rotation of the hip. The effects go further but essentially applying wedges to any foot type will not bring about the same results and it may be the reason that the research shows no real lasting changes though of course clinically these may be obvious. Is it possible that the successes with wedges have depended on the foot types they were applied to ?
What pronated and supinated feet do is upset normal gait patterns - supinated feet inhibit internal rotation of the tibia, knee flexion and internal rotation of the hip whereas pronated feet inhibit external rotation of the tibia, knee extension and external rotation of the hip. The effects go further but essentially applying wedges to any foot type will not bring about the same results and it may be the reason that the research shows no real lasting changes though of course clinically these may be obvious.
Forget about rotations and motions - knee OA is about moments and forces.
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Is it possible that the successes with wedges have depended on the foot types they were applied to ?
We testing hypothesis that those with feet at STJ everted end range of motion are more likely to respond to lateral wedging - ie they change the knee adductor moment, but can't change motions/rotations.
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Craig Payne
Department of Podiatry
La Trobe University
Melbourne, Australia http://www.latrobe.edu.au/podiatry
__________________________________________________ ___________________________________ God put me on this earth to accomplish a certain number of things - right now I am so far behind, I will never die.
The views expressed above are those of the author and not that of La Trobe University This is where I am, where are you?
Teichtahl et al, J Sci Med Sport 2006, 9(1-2):67-71 "Foot rotation - a potential target to modify the knee adduction moment. This study finds an association between foot rotation and the knee adduction moment during late stance - implying that changing foot kinematics can modify the medial tibiofemoral joint load during gait. Andrews et al, J. Orthop Res 1996, 14(2):289-95 "Lower limb alignment and foot angle are related to stance phase knee adduction in normal subjects: a critical analysis of the reliability of gait analysis data". The study suggests that the alignment of the lower limb and foot progression angle can serve as predictors of knee joint loading in healthy individuals which may have implications for nonsurgical treatment of knee problems. There are people out there who think that foot rotation and obviously subsequent tibial rotation do influence knee loading and the knee adduction moment. It seems that in spite of many years of gait analysis there is still no one answer, probably because there are many answers.
Effects of disease severity on response to lateral wedged shoe insole for medial compartment knee osteoarthritis. Arch Phys Med Rehabil. 2006 Nov;87(11):1436-41
Shimada S, Kobayashi S, Wada M, Uchida K, Sasaki S, Kawahara H, Yayama T, Kitade I, Kamei K, Kubota M, Baba H
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OBJECTIVE: To determine the effects of lateral wedged insoles on knee kinetics and kinematics during walking, according to radiographic severity of medial compartment knee osteoarthritis (OA).
DESIGN: A prospective case control study of patients with medial compartment OA of the knee. SETTING: Gait analysis laboratory in a university hospital.
PARTICIPANTS: Forty-six medial compartment knees with OA of 23 patients with bilateral disease and 38 knees of 19 age-matched healthy subjects as controls.
INTERVENTIONS: Not applicable.
MAIN OUTCOME MEASURES: We measured the peak external adduction moment at the knee during the stance phase of gait and the first acceleration peak after heel strike at the lateral side of the femoral condyles. Kellgren and Lawrence grading system was used for radiographic assessment of OA severity.
RESULTS: The mean value of peak external adduction moment of the knee was higher in OA knees than the control. Application of lateral wedged insoles significantly reduced the peak external adduction moment in Kellgren-Lawrence grades I and II knee OA patients. The first acceleration peak value after heel strike in these patients was relatively high compared with the control. Application of lateral wedged insoles significantly reduced the first acceleration peak in Kellgren-Lawrence grades I and II knee OA patients.
CONCLUSIONS: The kinetic and kinematic effects of wearing of lateral wedged insoles were significant in Kellgren-Lawrence grades I and II knee OA. The results support the recommendation of use of lateral wedged insoles for patients with early and mild knee OA.
I have not applied wedges clinically for OA but have thought about the concept for some time. I have a much more simplistic view of how these work- which is purely in the frontal plane. I feel that the lateral wedges tilt the tibia in the frontal plane when the STJ can't accommodate to the wedge. I don't think much internal leg rotation is happening.
In view of all the studies, it seems that lateral wedges have more of an affect on the knee then medial. I assume this is because the STJ has the ability to invert much more than evert, esp in the max pronated patient, which can't evert at all. That being said, most can accommodate better to the varus wedge rather than the valgus at the level of the STJ due more available ROM.
With respects to the max pronated patient (which most knee OA are), they would repond to a lateral wedge much like someone with a triple arthrodesis. Both are standing in heel valgus without the ability to pronate further. As such, the GRF of the lateral wedge must be resolved proximally with little triplanar motion since the STJ has little/no movement. The tibia is thrust medially in the frontal plane and genu valgum is the result.
Lateral foot wedging for medial knee OA
the varus deformity of medial compartment osteoarthritis
) - we tested several different length wedges - only the full length reduced knee abductor moment (and abductor moment increase is numero uno risk factor for medial knee OA).
Linear Mode
