Windswept knee deformity is a problem with the alignment of the knees. It’s a rare condition nowadays, but one we do see from time to time in our clinics.
So what exactly does “windswept” refer to, what causes it and – most importantly – how would you treat it? Here’s a brief guide to an unusual but challenging condition.
Understanding knee alignment
Windswept deformity is what we call a malalignment issue. Think of your knees as the midpoint in an imaginary line running down each leg. This line (doctors call it the “long axis of the leg”) starts in the centre of your hip and runs down to your ankle. In an ideal world, the axis would fall in the middle of your knee joint. In reality, most people’s alignment isn’t quite so perfect. Most of us have knees that point either outwards or inwards:
Varus alignment – is the medical term for knees that angle outwards, arching the legs (“bowlegged”)
Valgus alignment – is when the knees point inwards, towards each other (“knock knees”)
You can find out more about the implications of varus and valgus knees in this article: I’m a bit knock kneed / bow-legged: is that a problem?
What are “windswept knees”?
While most people’s alignment tilts either inwards or outwards on both knees, windswept deformity (WSD) is different. With WSD, one knee is in valgus misalignment while the other is varus. This gives the condition its very visual name. The legs appear to lean in the same direction, like an object that has been blown by a strong gust of wind.
What causes windswept knees?
The potential reasons are quite varied. In children, windswept deformity is usually linked to bone disorders like rickets (now rare in developed countries), growth issues or rare genetic conditions such as Blount’s disease (tibia vara). In adults, it’s more likely to be an acquired condition. Common causes in adults include:
Past surgery – if you’ve had an osteotomy or an operation to remove your lateral meniscus
Injury – if you’ve badly damaged your knee, for instance by fracturing the outer side of your tibial plateau (the upper surface of your shinbone)
Inflammatory disease – if you suffer from an inflammatory joint condition like inflammatory arthritides or rheumatoid arthritis
Degenerative arthritis – if you develop “wear-and-tear” arthritis: windswept deformity is 20 times more common in people who suffer from osteoarthritis
Are windswept knees a problem?
Misalignment in the knees isn’t necessarily a problem. As we’ve seen, some degree of malalignment in adulthood is very common. The key is whether it progresses – ie gets worse over time – and / or starts to cause symptoms. What are the potential symptoms of windswept knee deformity? The main ones are:
Instability – as the centre of balance in your legs shifts, you become more prone to falling
General discomfort – the imbalance puts more pressure on the outer-side muscles and bones in one joint, and the inner parts of your other knee, causing persistent pain through the hips, knees and ankles
Pain – the pressure points can begin to cause cartilage wear and acute pain in certain parts of the knee joints.
How do you diagnose windswept knees?
Interestingly, it’s quite common for loved ones to notice the condition before the patient does. That’s partly because acquired windswept deformity is insidious; like osteoarthritis, it tends to creep up on you over time. In the early stages, many people imagine it’s just part of the ageing process. In clinic, we can usually identify WSD with a physical examination. After that, we would normally want to order some imaging so that we can take a more detailed look at the overall alignment of your legs.
What are the treatments for windswept knees?
If windswept deformity is beginning to cause problems, we always start with conservative treatments. That usually means:
Physiotherapy – to help you build up strength in the supportive muscles around your knees and to improve the mobility of your joints
Bracing – If the deformity is still correctable – meaning we can manually straighten your legs to a degree – we may try to correct the deformity with a brace (though the braces can be quite bulky and tricky to get used to).
But if conservative approaches don’t work, we can look to corrective surgery instead. The two main operations here are:
Osteotomy
This is a procedure that’s designed to relieve painful pressure on a specific section of the knee joint. We remove a small wedge of bone near the joint in order to gently alter the alignment of the leg and shift your body weight away from the damaged compartment and onto healthier cartilage.
Total knee replacement
Knee replacement is an operation for joints that are suffering from serious, ongoing pain or stability problems. With WSD, the goal is to completely realign and restabilise your legs, and this normally involves both knees at the same time, with a specialised implant design to straighten each limb alignment and properly redistribute the mechanical forces going through your legs. Though knee replacement for windswept deformity is complex, studies have shown it can be highly effective when the surgeon carefully tailors the soft tissue balancing and alignment angles for each distinct knee.
Noticed a worrying shift in your knee alignment, or concerned about a loved one’s changing balance? We’re here to help. Whether you have questions about corrective surgery, want to discuss a specific joint concern or just need some expert reassurance, you can call or email us to book an appointment and get help with the next steps. We’ll be delighted to help you find the support you need.
