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Author Topic: Which Brace  (Read 25879 times)

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Offline Snoopydog

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Which Brace
« on: November 30, 2007, 05:19:21 PM »
Hi people,
Sorry if this has been asked before!

In February this year I had a skiing accident (after 20yrs+ with no probs :()which snapped my ACL and did other damage to the other ligaments surrounding the knee joint-I had an operation in the Austrian clinic the next day where they pinned and replaced the ACL.
The operation seems to be a great success although I am lacking that last 10% of movement.
Although I only ski once a year (For 2 weeks) I do play a lot of squash and mountain bike riding, therefore I am looking for a brace that will enable me to get back on the squash court and bike but will also give me confidence and some piece of mind to ski next year.

I am looking at either the Donjoy armour or the Donjoy Playmaker, does anyone have experience with these or are able to suggest any other 'off the shelf' braces?
I understand that there are different thoughts on wearing a brace or not but I feel that it will help me.

Thanks in advance
Snoopydog

Offline Michael_Frind

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Re: Which Brace? -- Functional knee bracing for alpine skiing...
« Reply #1 on: December 11, 2007, 02:03:19 AM »


Dear Snoopy,

I would be intrigued to hear more about your knee injury.  You noted that the ACL was reconstructed; which graft was used?  And, what other ligaments were damaged, and to what extent?

The topic of functional knee bracing (both the various braces as well as the merits of wearing bracing for ligament-injury-history knees in general) is often discussed on Bob's ACL WWWBoard (factotem.org), and I have posted a number of responses regarding bracing in the context of alpine skiing.  Medical-journal articles and other professional-quality resources dealing with skiing-type knee injuries as well as ACL rehabilitation and other knee-related topics can be found in the Knee Library at http://factotem.org/library.  I will, however, discuss knee bracing for alpine skiing briefly here.

Any good-quality dual-hinged, dual-upright-type brace will protect very nicely against sideways forcing and injurious hyperextension.  The CTi2 will do this nicely, as will the products from Townsend and also DonJoy.  The DonJoy Playmaker, an economy neoprene sleeve with side struts, is too low-end a brace to be suitable for serious knee-injury protection.

You mentioned that you are heavily involved in squash (a lot of planting and twisting) and mountain biking, in addition to the alpine skiing.  With this in mind, it is clear that a custom-made functional brace would be best.  My first choice would be the Ossur (formerly Innovation Sports) CTi2, since this brace brings the advantages of full-tibial-shell construction (so, it grasps the tibial crest reliably), carbon-fibre-composite foam-core construction (so, maximum strength at minimum weight), a lifetime structural-mechanical warranty, and a one-year free-refit period.  The CTi2 is also unique because it brings the optional ski-boot attachment, a device which very nicely protects the skier's knee against twisting.  The device, discussed in more detail in the posting below, works by ensuring that the ski binding releases reliably (instead of the knee being twisted).  The benefits of such a device become clear when one considers how many skiing knee injuries are due to twisting.

http://www.factotem.org/cgi-bin/kneebbs.pl/read/325045

The goal of the ski-boot-attachment-equipped CTi2 is to ensure that, in the event of the ski being twisted (so that it would apply an axial twisting force on the tibia, hence potentially ruining the knee), the twisting force would be managed by the brace frame (which would then convert it into harmless compression where its upper shell meets the sides of the thigh, given that the knee would be flexed at about 90 degrees), whereupon it would then ensure that the bindings release in a timely manner.  Otherwise, without such a device, the bindings might not release before the knee is twisted.  This is so because the bindings cannot detect the torque at the knee, since said torque is itself a function of the angle at which the knee happens to be flexed at that point in time.

I think the CTi2 with the ski-boot attachment is by far the best option for anyone who partakes in alpine skiing.  The ski-boot attachment can easily be removed for other activities.  The advantages of dual-upright full-tibial-shell construction (i.e. much better protection against all types of abnormal forcing than any neoprene sleeve could ever provide) is especially desirable in your case, given that your knee's injury history involves not only the ACL, but other ligaments as well.

If you are tightly constrained to off-the-shelf knee bracing only, then you will have to make do with a brace that does not protect against twisting-type forcing in alpine skiing.  My first choice here would likely be the Ossur Morph (now also sold, in a slightly different form, as the CTi OTS), although the DonJoy Armor (and its siblings Legend and 4Titude) would be satisfactory too.  Keep in mind that the Armor is made of bent-to-shape stamped aluminum, and thus does not have the advantage of high strength at minimum weight that carbon-fibre braces like the CTi2 and Morph/CTi OTS have.  Also, if you are looking at the Armor, the Townsend Rebel series (also made of stamped aluminum) would be satisfactory.

Please keep me posted with regards to the knee.

Yours truly,
Michael Frind
Knee Library http://factotem.org/library
Profile: factotem.org/cgi-bin/kneebbs.pl/profile=michael+frind

Offline Snoopydog

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Re: Which Brace
« Reply #2 on: December 14, 2007, 07:19:22 PM »
Hi Michael,
In response to your question, I had a ACL replacement with semitendinosus and  gracilistendon fixed with trans fix and hybrid technic bioresorbable, also ruptured medial collareral ligaments. (quoted from my Austrian report)

What would be your view on the Breg x2k unlimited (apparently suitable for horse riding which is something else I do), Innovation Edge, Ossur CTi, DonJoy Armor with FourcePoint, DonJoy Armor (Extreme)Townsend Rebel PRO or Townsend Rebel in order of preference?

I am limited in my budget as to what brace I can purchase therefore 'off the shelf' is the way i have to go.

Regards
Snoopydog

Offline Michael_Frind

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Re: Which Brace -- Choosing amongst a variety of off-the-shelf knee braces....
« Reply #3 on: December 24, 2007, 07:26:00 PM »


Dear Snoopy,

Your knee-injury history entails a torn-and-reconstructed ACL, along with a torn MCL that has presumably scarred over and healed on its own adequately.  But the reliable protection against sideways forcing and injurious hyperextension (offered by any of the braces you mentioned) would be highly desirable.  And, for alpine skiing in particular, the protection against twisting-type injuries (as available only on the Ossur CTi2, now sold as the CTi-Custom) would be very beneficial.  Unfortunately, given that your financial situation restricts you to off-the-shelf bracing, this also means protection against twisting is not available to you.

You asked for my views on the Breg X2K Unlimited , Innovation Edge, Ossur CTi (presumeably you mean the off-the-shelf CTi-OTS), DonJoy Armor with FourcePoint, DonJoy Armor (Extreme)Townsend Rebel Pro or Townsend Rebel in order of preference.

First, I will list my order of preference, from first choice to last choice.  Please note that 1 and 2 are tied.

1. Innovation Sports/Ossur Edge or Morph.  The Edge has been replaced by the CTi-OTS (in other words, the CTi-OTS is the same as the Edge but with a few cosmetic changes), and the Morph is still available.  I would probably choose the Morph over the CTi-OTS, simply because the Morph has adjustable cuffs instead of flexible ones.  (My first choice overall would still be the CTi Custom, formerly known as the CTi2, which is the brace I have been wearing for the past decade.  Please remember that the CTi-OTS and CTi-Custom are very different braces, just like the Edge and CTi2 were very different braces.)
2. Innovation Sports CTi OTS.  As noted above, this is essentially the same as the Edge, a well-regarded carbon-fibre off-the-shelf brace with flexible cuffs. 
3. Townsend Rebel series (Regular, Pro, Lite, etc.)
4. DonJoy Armor series, with Fource Point hinge or without
5. Breg X2K series.

Now, I will discuss the various braces, in reverse order.

Breg's general frame design was a somewhat veiled copy of the Innovation Sports (now Ossur) CTi2 (now renamed the CTi), and thus was designed from the start to avoid the inside-upper-thigh area.  This is why the CTi2 is a good choice for horseback riding and similar activities that involve straddling something ridden.  But the Breg X2K has the drawback of being made of cheap stamped aluminum, bent to shape.  This results in a rather heavy brace of unimpressive strength.  Breg's braces are also expensive: they cost only a few dollars to make (stamp out the aluminum in a press and quickly bend it to shape), but are sold for the same price as carbon-fibre braces.  Breg continues its questionable practice of selling bent-to-shape off-the-shelf braces (stamped from a slightly different aluminum sheet, merely for legal reasons) as "custom-made", a practice I have repeatedly condemned as fraudulent.

DonJoy's Armor series braces are adequate, but like the Breg, they are made of stamped aluminum.  DonJoy, however, is honest in selling its Armor series (and the similar 4Titude and Legend) as off-the-shelf.  What I do not like about DonJoy's frame design (as found on the Armor, as well as the related products and also the custom-made Defiance) is that it deliberately avoids the tibial crest (i.e. the bony ridge running down the front of the shinbone).  This means that DonJoy's braces sit merely on the soft tissues of the leg.  So, when the muscles are activated, the entire brace frame shifts slightly with respect to the leg bones.  This is not a good design.  Also, no anti-twisting ski-boot attachment is offered.  DonJoy does offer ski-boot attachments, but these are merely intended to address the chafing problem that arises from the posterior-tibial-cuff frame design; they do nothing biomechanical.  Another drawback of DonJoy's frame design is that the footwear must be removed in order to don or doff the brace.  (DonJoy continues to advertise its frame design as having "the four points of leverage" with regards to providing anterior-drawer-counteraction forcing for the ACL-deficient knee.  Actually, any of the braces discussed here can provide such anterior-drawer-counteraction forcing: all that is necessary is to appropriately tighten the straps immediately above and below the knee.)

The Townsend Rebel series are again made of stamped aluminum, and are sold as off-the-shelf.  They can be customized, but are not custom-made.  The only custom-made functional braces Townsend makes are the Premier and the Air/Original; these are good braces, and I recommend these over the Rebel series.  Regrettably, Townsend does not offer a full-tibial-shell brace with a foam-core construction.  Nor does this firm offer a ski-boot attachment for any of its braces.  Amongst all the aluminum-framed (hence off-the-shelf, since all aluminum braces fall within the off-the-shelf realm) braces, the Townsend Rebel series would be my first choice...but I would definitely prefer the lightness and strength of carbon-fibre construction.

Innovation Sports (Ossur) remains the only major firm to produce carbon-fibre off-the-shelf bracing.  The Morph (with adjustable lateral arms) was originally intended to replace the Edge (which merely had flexible lateral arms).  When Iceland-based Ossur bought California-based Innovation Sports, the Edge was brought out again, but with a few cosmetic changes.  Ossur decided to brand it as the CTi-OTS.  Under Innovation Sports, the Morph and Edge had lifetime warranties (in fact, they were the only off-the-shelf braces to have such warranties), but now under Ossur the warranty is 2 years.  (The CTi-Custom has the same lifetime warranty as the CTi2.  It really is regrettable that your health insurance is not willing to cover a custom-made knee brace.) 

The Morph and Edge/CTi-OTS are carbon-fibre-composite braces, and represent one of the best off-the-shelf designs.  They bring excellent protection against injurious hyperextension, but are not quite as good at protecting against high-impact sideways forcing (e.g. in contact sports) as the CTi-Custom (or CTi2). 

Choosing between the Morph and CTi-OTS, I would probably choose the Morph.  I would also try out the Townsend Rebel.  Please note that different models of off-the-shelf braces fit different leg shapes differently.  If your leg shape is unusual (for example a markedly curved tibia, also known as recurvatum, or if you are bow-legged or knock-kneed), then getting any off-the-shelf brace to fit will be very difficult.  Things might be slightly easier for legs that are unusual in terms of disproportionate thigh-versus-calf sizing.  Townsend, upon special request, will size the top and bottom halves of the Rebel series differently (e.g. a large-size thigh and a medium-size calf), but even the results are unlikely to be as good as with custom-fabricated bracing.  Another possibility is the Ossur C180, a lightweight brace made of prepreg carbon-fibre material and thus very amenable to heating (with a simple heat gun) and reshaping in the field. 

If you can try out the various off-the-shelf offerings from Ossur and Townsend, and if your leg shape is not too different from average, and if your clinician/orthotist is willing to make minor modifications to the brace as required, then you should be able to obtain satisfactory results with one of these off-the-shelf braces.

I would be intrigued to hear about your experiences with the brace you choose.

Yours truly,
Michael Frind.
Knee Library http://factotem.org/library

Profile: factotem.org/cgi-bin/kneebbs.pl/profile=michael+frind

Offline histerbeto

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Re: Which Brace
« Reply #4 on: January 08, 2014, 11:26:43 PM »
friend Michael_Frind
friend, could you explain the design deficicnecias donjoy, particularly the anchor in the back of the tibia? that the difference between the anchor and the anchor back in the front of the tibia?

Offline Slippyknee

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  • LK dislocation, lcl laxity, pcl torn twice,
Re: Which Brace
« Reply #5 on: January 13, 2014, 07:41:02 AM »
hi there Michael
do you know anything about bracing for pcl injuries?
I've been looking for a while now but cannot find any good recommendations
for a good pcl brace!!
quick knee history, dislocated knee resulting in pcl,lcl tears cartledge trim. 20% lateral meniscus removed & a tear fixed. tore pcl again last yr spent 5months in a jack pcl brace(24/7)
returned to sport (tennis, badminton) with kne heavily strapped & using a medi m4s.

I'm currently looking @  getting a custom townsend brace?
your thoughts would be appreciated.
many thanks barry
LK dislocation,  cartlege trim, 20% lateral meniscus removed
Lcl laxity,  pcl tears, mcl tear

Offline Michael_Frind

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Re: Which Brace - DonJoy (DJ Ortho) bracing design aspects...
« Reply #6 on: January 27, 2014, 06:49:12 AM »
friend Michael_Frind
friend, could you explain the design deficiencies of donjoy, particularly the anchor in the back of the tibia? that the difference between the anchor and the anchor back in the front of the tibia?

Hi Histerbeto,

You asked about the design deficiency of DonJoy (now DJ Orthopedics) dual-upright functional knee braces (such as the Defiance, Legend, 4Titude, and so on).

DonJoy's rigid-framed knee braces all employ the same fundamental design: the lower half of the brace wraps only around the rear of the calf, thereby resting entirely on soft tissue and thus completely avoiding the tibial crest (shinbone).  Because the tibial crest (which can easily be felt as the bony ridge on the front of the lower leg) is the only suitable anatomical landmark via which a brace's lower shell can grasp the lower leg, it is inherently highly appropriate for a functional brace to be designed to interface as snugly as possible with the tibial crest. 

In light of the fact that ACL injuries very often involve twisting (and thus an ACL-injury-history knee forever retains a significant vulnerability to further twisting injuries, especially given that the standard single-bundle ACL graft only reproduces the anteromedial bundle of the natural ACL, thereby leaving the posterolateral bundle completely absent), any resistance to twisting that an externally worn brace can provide is highly desirable.  This is why traditional full-tibial-shell braces (like the Townsend Air/Original and the Innovation Sports CTi2) were designed with this foremost in mind.  (In the past few years, these two firms have both changed ownership, and their product focus has also changed.  Townsend is now part of the French firm Thuasne, and it now focuses on its open-frame Premier series, whose design offers less tibial-crest-gripping ability than the Air/Original series did.  A similar scenario has played out at Innovation Sports, which is now owned by the Icelandic firm Ossur.  The CTi2 has now become the CTi-Custom, with a concomitant shrinkage in lower-shell length and a subtle-yet-significant reduction in tibial-crest furrowing.  Both the Premier series and CTi-Custom remain very good braces, but the unique attributes for which the Townsend and Innovation Sports braces became famous for have, over the past half-decade, gradually been watered down.)

Unfortunately, the presence of the easily sheared soft tissues around the leg bones reduces the opportunity for a tibial-crest-grasping full-tibial-shell brace to grip the tibia well enough to prevent ACL-injurious twisting.  This is exactly why no knee brace can be guaranteed to prevent ACL injury.  In other words, a brace of full-tibial-shell design probably will not provide enough resistance to twisting to make a difference in violent planting-and-twisting-type ACL injury scenarios.

I realize that DonJoy, whose braces specifically avoid the hard-to-fit tibial crest, touts its "knee guarantee".  This pays 750 to 1000 US dollars (depending on the DonJoy brace model chosen) to anyone who reinjures an ACL-reconstructed knee while wearing one of its tibial-crest-avoiding braces.  Again, it needs to be made clear that no brace can be counted on to protect against twisting-type injuries.  And for the reasons noted above, this applies especially to DonJoy products.  The reason DonJoy can offer such a guarantee is because they know that any reasonably intelligent and foresightful person who tears an ACL (and who undergoes the grindstone of reconstructive surgery and the ensuing gruelling rehabilitation) will be extremely strongly motivated to take every precaution to avoid reinjuring the knee; for most people, this includes avoiding high-intensity planting-and-twisting-type sports.  So, in any case, I consider DonJoy’s Knee Guarantee to merely be overdone marketing.  In fact, I think every person who values the ability to walk and do other knee-dependent activities should see DonJoy’s Knee Guarantee as a personal insult.  Given how tremendously important the ACL is to both human-knee functionality as well as to long-term knee health, and given how enormously essential the knee is to nearly every physical activity, I think it should be abundantly clear that the ACL is worth far more than 1000 dollars!
 
For purposes of preventing injurious hyperextension and for protecting against sideways forcing, a DonJoy brace is perfectly fine.  But the fact that DonJoy continues to avoid interfacing with the tibial crest tells me that their priority is ease of fitting (i.e. convenience) instead of focusing on making their braces interface as securely as possible with the leg bones.  Here we see why DonJoy braces are so popular with doctors and clinicians -- because they sit solely on soft tissues, any error of fit (e.g. due to errors in measuring) will simply be accommodated by deformation of the leg's soft tissues (i.e. the muscles, in particular the calf muscles).  This is so because all dual-upright functional knee braces are inherently designed so that their key strap anchorage point is at the top (proximal end) of the calf musculature (so, the brace is worn so that the strap immediately below the knee is tightest, and the bottommost strap is second-tightest).
 
Because the knee ligaments connect the leg bones (femur in the upper leg, and tibia-and-fibula in the lower leg), the closer a brace frame interfaces directly with these bones, the better it will be able to inhibit abnormal movement while still allowing normal movement.  Given the aforementioned limitations imposed by the presence of the bone-surrounding soft tissues, the only way around this is to connect the brace's lower shell directly to some type of ankle-encasing device, as the CTi2 brace was able to do with its optional ski-boot attachment.  (This option is no longer available: Ossur ended it as the CTi-Custom replaced the CTi2.)

So, all things considered, I think it is best to think of a functional knee brace primarily as protection against injurious hyperextension and sideways forcing.  With this in mind, the DonJoy Defiance (and its siblings from this firm), the Townsend Premier series, and the Ossur CTi-Custom really all fulfill the same protective function.  The same goes for other dual-upright hinged knee braces from other manufacturers.

Again, please remember that it is not a good idea to expect significant protection against twisting injury from any of the functional braces currently on the market.  In other words, planting your foot and violently twisting your knee is a recipe for ACL tearing (or re-tearing), regardless of what orthosis you happen to be wearing.

Yours truly,
Michael Frind.
 
Profile: factotem.org/cgi-bin/kneebbs.pl/profile=michael+frind

Offline Michael_Frind

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Re: Which Brace
« Reply #7 on: January 31, 2014, 03:01:33 AM »
hi there Michael
do you know anything about bracing for pcl injuries?
I've been looking for a while now but cannot find any good recommendations
for a good pcl brace!!
quick knee history, dislocated knee resulting in pcl,lcl tears cartledge trim. 20% lateral meniscus removed & a tear fixed. tore pcl again last yr spent 5months in a jack pcl brace(24/7)
returned to sport (tennis, badminton) with kne heavily strapped & using a medi m4s.

I'm currently looking @  getting a custom townsend brace?
your thoughts would be appreciated.
many thanks barry

Hi Barry,

Depending on your expectations of what a functional brace can do for your knee, finding "a good PCL brace" is not as easy as your doctor (orthopedist), orthotist (clinician), or the knee-brace manufacturers might want you to think.  While bracing firms offer "PCL versions" of their braces, really all that these versions amount to is an additional strap or something of that ilk.  As I will discuss shortly, there are some fundamental limitations to what knee braces can do.

I recommend starting by taking a moment to think about the biomechanics of how knee braces interact with the leg.  (If you would like, I can e-mail you some simple diagrams.  There is no magic to how knee braces work.  The only understanding needed is that of drawing free-body diagrams, which you will remember from high school.  No calculations are needed: a sheet of paper and a pencil are all you need.)
 
So, let's take a moment to review the mechanical aspects germane to how a knee brace works when it is on your leg. 

Bracing for PCL injuries has one core similarity to ACL injuries: the need for protection against injurious hyperextension and also abnormal sideways forcing.  Protecting against damaging overextension (i.e. injurious hyperextension) is particularly important for any knee that has any injury history involving the PCL, LCL, or ACL.  This is so because all of these ligaments can be damaged by hyperextension-type injury, thus proving that these ligaments have some role in constraining how far the knee extends.  (Overall, the ACL and PCL together are the key limiters of extension.)
 
Because your knee injury involves the PCL and LCL, it is clear that violent forcing was involved.  This could have been hyperextension (of the type just discussed), or it could have been posterior-drawer forcing (i.e. with knee flexed, the tibia was violently forced backwards, as can occur when a knee impacts a car dashboard during a frontal collision; similar forcing can also occur in alpine skiing or in pedestrian-car collisions, among other scenarios), or it could have been some combination of these.  The knee could also have been forced outwards (thus explaining the LCL damage), a scenario that can occur in high-speed sports, collisions involving motor vehicles, and also contact/collision sports.  Certain modes of planting and twisting (especially if occurring in conjunction with any of the foregoing) can also damage the PCL.  (Granted, the ACL is the most commonly injured ligament when planting and twisting is involved, but it is not the only one.)
 
The mode of forcing that you want the knee brace to protect against is key.  Any properly fitted, good-quality (i.e. adequately engineered for structural-mechanical strength) rigid-framed, dual-upright functional knee brace (with one hinge on each side of the knee) will protect the knee against damage via the hyperextension mode.  Such a brace will also protect the knee against sideways forcing.  But twisting and drawer-type forcing is where braces become less useful.
 
The easiest way to conceptualize the limitations of functional knee braces and their interactions with the leg is to consider the forces at the brace-leg interface.  Any externally worn brace can only interact usefully with the leg in compression at each point of interface.  And, this is exactly what happens when a knee-brace-wearing leg is subjected to violent hyperextension or sideways forcing: assuming that the brace is properly fitted (and worn correctly) and that the frame and hinges do not fail, the brace effectively shields the knee against such forcing.  (In this example, I am assuming that hyperextension-type forcing is applied to the knee and not directly to the brace frame itself, and that the brace fits the leg snugly, securely, and comfortably, so that the brace and leg effectively work together as a unit.  Meanwhile, a sideways force often hits the brace at the hinge, which is fine as long as the brace is engineered for sufficient strength, although in my analysis I assume the forcing to be exerted directly on the knee joint itself.  The custom-made carbon-fibre-composite braces from DonJoy/DJ Ortho, Townsend/Thuasne, and Innovation Sports/Ossur all meet the requirement of good structural-and-mechanical engineering, so any of these is a safe bet.  At the other end of the quality spectrum is Breg, which makes the poorly-designed Fusion and other products such as the X2K.  Breg's products are unimpressive and cheaply made, yet are sold at high prices.)

For hyperextension-type forcing of a braced knee, compression will be felt at the straps that run behind the knee, and at the top-front and bottom-front of the brace.  Meanwhile, for sideways forcing, compression will be felt at one hinge (the outboard one if the knee is forced outwards; the inboard one if the knee is forced inwards) as well as at the top side of the brace frame (on the opposite side of the hinge at which compression is felt).

Now, let us consider twisting.  The problem with expecting protection against twisting from an externally worn brace is that the leg bones are surrounded by shear-prone soft tissues.  These bone-surrounding soft tissues interfere with any brace's ability to grip the leg bones securely enough to arrest violent twisting.  Although it is possible to design the brace to grip the tibial crest (shinbone, i.e. the easily felt bony ridge running down the front of your lower leg), and although such a design attribute (which I refer to as a full-tibial-shell brace, such as the Townsend Air/Original) is still desirable, it is important to remember the limitations imposed by the soft tissues of the leg.  In other words, don't expect any brace to give you immunity to twisting-type knee injuries or re-injuries.  (Remember, too, that a full-tibial-shell brace covers more skin area on the leg, which means a bit more sweatiness during hot weather or vigorous activity, as compared to an open-frame brace like the DonJoy Defiance.  But for knees with multiple ligament injuries, I consider the benefits of a full-tibial-shell design to outweigh the minor issue of a few extra square inches of brace-covered skin.)

Meanwhile, drawer-type forcing (i.e. the tibia being violently forced rearwards for PCL tearing or forwards for ACL tearing, with the knee partly flexed) is exactly the mechanism used by orthopedists for diagnostic testing.  These are the classic Lachmann drawer test, anterior drawer test (both for the ACL) and posterior sag test (or posterior drawer test) for the PCL. 

Violent rearwards forcing of the tibia (with the knee partly flexed) will damage the PCL (or other structures, if the PCL has already been compromised).  From your description, your natural PCL was torn and then reconstructed; the reconstructed PCL was subsequently torn, and now you are looking for a functional brace that can stand in for the missing PCL. 

Unfortunately, just like the limitation imposed (by the aforementioned presence of soft tissues) on twist-protection, it is not feasible to design a knee brace to protect against drawer-type forcing.  So, again, regardless of which brace you get, you will still have to be careful with your knee.  Once again, I prefer to think of a knee brace simply as protection from sideways forcing and injurious hyperextension.

Please keep in mind that the only feasible way to anchor any functional brace on the knee (and thus to ensure that it does not slip down the leg while in use) is to have the strap immediately below-and-behind the knee tightest.  Effectively, the brace sits on the calf (gastrocnemius/soleus complex) musculature.  (For most people, this is the only location where a brace strap can be worn very tightly without causing muscle cramping.  In simplest terms, trying to tighten other straps on the brace to this same amount of tightness can be expected to result in discomfort, although for some people it can be feasible for short periods such as a tennis match.  But it would not be feasible for all-day wearing, such as rough-terrain hiking.) 

So, for a full-tibial-shell brace, having the strap located immediately below the knee tightest ensures that the brace's tibial shell (which wraps around the front of the lower leg) is firmly pulled onto the tibia (and if that shell contains a suitably pronounced furrow, the it will register on and capture the tibial crest).   The brace's lowermost strap is also tightened, but not as much as the strap immediately below the knee.  So, now that we have the lower half of the brace anchored onto the leg, let us consider what happens at the upper half.

One caveat arises here: knee brace companies have, for many years, been touting their designs, with various strap arrangements that aim to counteract abnormal drawer-type forcing.  But when you think through these arrangements carefully, it becomes apparent that their ability to protect against injuries is seriously limited by how the brace interacts with the leg.  (Further complexities arise when one considers person-specific variables such as prior training, leg-muscle strength, reflexes, and how much proprioception [kinesthetic sense] was permanently lost in the tearing of the natural, original ligaments and other tissues; keep in mind that those natural tissues contain nerve endings responsible for feeding back position-in-space information to the brain in order to enable optimal decision-making for muscle activations.  This natural feedback is lost when ligaments are torn, and although some nerve endings can regrow in a reconstructed ligament, there remain serious questions about how usefully connected those regrown nerve endings end up being.  There is still a lot of research to do in this area.)

For an ACL-injury-history knee, brace manufacturers (most prominently DonJoy/DJ Ortho) argue that that if you maximally tighten the strap immediately above-and-behind the knee, then the tibia will be forced forwards, thereby counteracting anterior-drawer-type looseness (or protecting against anterior-drawer-type injury).  The problem with this reasoning is that the soft tissues behind the femur are quite thick, and the hamstring tendons are located here as well.  The end result is that it is infeasible to apply a strong enough forwards force on the distal end (i.e. the knee end) of the femur that anterior-drawer-type forcing is reliably prevented or counteracted (all while still keeping the brace reasonably comfortable to wear on the leg).

Another problem with trying to arrest anterior-drawer-type forcing with a knee brace is that any attempt at using a brace in the way described in the foregoing paragraph rapidly becomes less effective as the knee is flexed.  It is easy to conceptualize how a brace can (in theory) force an ACL-deficient knee (in which the tibia slides too far forwards with respect to the femur) into its correct alignment, if the knee is at full extension.  But as a knee is increasingly flexed (and in normal athletic pursuits, including the tennis and badminton that you pursue, the knee is normally always somewhat flexed), the top half of the brace increasingly interacts with the thigh in shear only.  And, as discussed earlier, a brace that interacts with the leg in shear cannot be very useful.  (Either the soft tissues of the leg shear, or the brace simply slips against the skin.)

So, for an "ACL version" brace, the brace is intended to be worn with the strap immediately-above-and-behind the knee being so tight that it would be uncomfortable to wear anyway.

For a PCL-specific situation such as yours, a similar situation arises: the brace is supposed to be worn so that it forces the distal end of the femur rearwards and the proximal (knee end) of the tibia forwards (so, the exact opposite of the ACL-specific scenario).  Again, although compression is involved in both cases, we have the problem whereby there exists enough soft tissue (e.g. behind the tibia) to interfere with the application of sufficient compressive forces to stop high posterior-drawer-type forcing.  Remember, too, that the massive quadriceps musculature at the front of the thigh connects at the patella, and there is a lot of tissue there that sits in front of the femur in this area.  Any rearwards compressive forces exerted by a brace strap must go through the quadriceps muscle-tendon unit at that location, and overtightening the strap there can cause cramping.

With this background in mind, and given the extensive and especially serious injury history of your knee, I think the Townsend Air/Original would be one of the most suitable braces for your knee.  With a full tibial shell, and worn with the intent of protection against injurious hyperextension, it would be helpful in preventing these types of injuries/reinjuries to your knee.  But please keep in mind that your PCL-and-LCL-injured knee will remain vulnerable to further problems -- and planting-and-twisting activities (such as vigorous tennis and badminton) are risky for it. 

So, I think a full-tibial-shell Townsend brace is a good choice, with other good-quality braces, such as the Townsend Premier, Ossur CTi-Custom, and DonJoy Defiance also being suitable (given that, as noted above, the key roles of functional knee bracing are the provision of protection against sideways forcing and injurious hyperextension).  Please remember that brace usage should be combined with diligently maintained leg musculature (i.e. training focused on strength, endurance, and proprioception).  But because of your extensive knee injury history, it will not be easy to select a suite of knee-safe exercises that is tailored (and safe) for your knee.  I recommend you discuss this in detail with both your orthopedist and a physiotherapist who specializes in the management of complex knee injuries.

Yours truly,
Michael Frind.

Profile: factotem.org/cgi-bin/kneebbs.pl/profile=michael+frind

Offline Slippyknee

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  • LK dislocation, lcl laxity, pcl torn twice,
Re: Which Brace
« Reply #8 on: January 31, 2014, 01:05:17 PM »
Stayed with medi
« Last Edit: March 14, 2016, 09:52:07 AM by Slippyknee »
LK dislocation,  cartlege trim, 20% lateral meniscus removed
Lcl laxity,  pcl tears, mcl tear

Offline sypo

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Re: Which Brace
« Reply #9 on: October 05, 2017, 01:21:29 PM »
Hi Michael - or anyone out there with a bunch of experience with knee braces,

I've snapped the ACL twice on my right leg from skiing. I've had it repaired twice (hamstring graft then patella tendon) and haven't skied for about 5 years, as I'm quite scared that I'll snap it again. However I've done a lot of rehab, as well as cycling and rowing, and I'm very keen to get back out on the slopes. Having read your (excellent and amazingly informative) previous posts, I understand that the CTi-Custom replaced the CTi2, but no longer has the ski-boot attachment.

Whilst I know that no brace will categorically prevent me rupturing my ACL again, what current custom brace (or off the shelf brace) would you recommend to give the best support and protection to my knee, whilst skiing?

Cheers,
 - Sypo.
« Last Edit: October 06, 2017, 12:24:41 AM by sypo »