What causes outside knee pain? How do you treat it? Let’s go over all of this and also review how one patient avoided a huge surgery.
What’s On the Outside of the Knee?
You have a couple of key structures here (1). They include the:
- Lateral meniscus
- Lateral joint compartment
- Popliteus tendon
- Iliotibial band
- Lateral collateral ligament and anterolateral ligament
The meniscus is a figure-8 shaped fibrous structure (shown here from above) that is a shock absorber for the knee joint. It has an outside part (lateral meniscus) which cushions the joint. The meniscus can become torn or degenerated. If you’re young, then a meniscus tear is more likely to cause pain. For patients over 35, it’s less likely that a meniscus tear is causing the pain (11). However, in either instance, a meniscus that isn’t doing its job may be causing the cartilage and bone to degenerate and cause outside knee pain.
The lateral joint compartment is the outside of the knee joint where the thigh bone (femur) meets the leg bone (tibia). There is cartilage here and when you start to lose cartilage and get bone spurs, this is called arthritis which can cause outside knee pain. In this case, this is called lateral compartment knee osteoarthritis.
There are two tendons on the outside of the knee including the terminus of the Iliotibial Band (aka the ITB) where it inserts into tibia as well as the popliteus tendon. The ITB begins on the outside of the pelvis and hip and travels down the outside of the leg. See my video below to find out more about that structure. If you have chronically tight ITB’s, this can eventually cause painful tendinopathy here. Another tendon that can cause outside knee pain is the popliteus which has its muscle belly on the back of the knee (see image here). This tendon can get damaged or beat up as well.
There are also two critical ligaments on the outside of the knee. One is the Lateral Collateral Ligament or LCL, which acts as the duct tape on the outside of the knee and stabilizes this area. The Anterolateral Ligament (ALL) is also on the outside of the knee and stabilizes this area and helps the ACL ligament (see the image to the right). These ligaments can be sprained or torn.
Finally, the fibula is the outside knee bone that attaches to the main leg bone (tibia) via strong ligaments. The bone can become bruised or the ligaments that hold it in place can become injured. Finally, there is a small joint between the fibula and tibia and this joint can become arthritic.
How do you Treat Outside Knee Pain?
Treating outside knee pain all depends on the cause. Oftentimes just rest or physical therapy is the answer, but if not, let’s review some state of the art treatments:
- Lateral meniscus-Tears in the outside meniscus that don’t respond to physical therapy are often treated surgically by cutting out the torn part (partial meniscectomy). However, recent research has shown this procedure to be no better than placebo or physical therapy, so there is no evidence that this surgery helps, despite its common use (2). Recently, research on platelet-rich plasma injections into the torn meniscus has shown this to be a promising treatment (3).
- Lateral compartment knee arthritis-Physicians will often want to inject steroids to help reduce pain and improve swelling, but we now know these shots kill off knee cartilage (4). Other options, if you have mild to moderate arthritis, include hyaluronic acid (HA), which is a lubricating gel or prolotherapy (prolo) which is a shot that causes a brief inflammatory healing response (5). Another injection that has been shown to be better than HA or prolo is platelet-rich plasma (PRP). Finally, if the arthritis is more severe, bone marrow stem cell injections have shown promise (6). If nothing else less invasive works, partial knee replacement is often recommended.
- ITB and Popliteus Tendon-The Iliotibial band can often be treated by rolling it out with a foam roller which can improve circulation (7). If this or physical therapy doesn’t help, in my experience a PRP injection can often help heal the ITB or popliteus tendon.
- Lateral Collateral Ligament or Anterolateral Ligament-These can be injured with trauma or wear and tear and can make the outside of the knee unstable. If these ligaments are sprained, then bracing as well as physical therapy to try to strengthen muscles is usually prescribed. If this fails, both of these ligaments can be surgically reconstructed (8,9), but we often find that a PRP injection can help and tighten them without having to rip out the existing ligament.
- Fibula-If this bone is bruised, this often takes weeks to months to heal. However, the ligaments that hold it in place can also be damaged and in my experience, these usually respond well to prolotherapy or platelet-rich plasma.
Fixing Outside Knee Pain to Ski the Haute Route in the Alps
The Haute Route is a 125-mile long, high mountain trail connecting Chamonix with Zermatt that takes seven days to ski with 43,000 feet of vertical. It was the dream of a patient of mine from Atlanta to make this trek on skis. However, in 2012 he was told that needed a knee replacement. However, this type of route would never be compatible with that procedure, hence he went looking for other options and found our clinic. Due to the severity of his knee arthritis, he was taken down to an advanced practice site in Grand Cayman where we can use culture-expanded stem cells derived from his bone marrow (10). In 2015 he skied the Haute Route in 6 days having never had that knee replacement! He’s now back for a tune-up treatment at 7 years after his initial knee stem cell injection.
The upshot? There are many things that can cause outside knee pain. Most will heal on their own. However, if they don’t heal, I would recommend using newer interventional orthopedics techniques rather than older surgical techniques!
(1) Schweller EW, Ward PJ. Posterolateral Corner Knee Injuries: Review of Anatomy and Clinical Evaluation. J Am Osteopath Assoc 2015;115(12):725–731. doi: 10.7556/jaoa.2015.148.
(2) Sihvonen R, Paavola M, Malmivaara A, et al. Arthroscopic partial meniscectomy versus placebo surgery for a degenerative meniscus tear: a 2-year follow-up of the randomised controlled trial. Ann Rheum Dis. 2018;77(2):188–195. doi:10.1136/annrheumdis-2017-211172
(3) Kaminski R, Maksymowicz-Wleklik M, Kulinski K, Kozar-Kaminska K, Dabrowska-Thing A, Pomianowski S. Short-Term Outcomes of Percutaneous Trephination with a Platelet Rich Plasma Intrameniscal Injection for the Repair of Degenerative Meniscal Lesions. A Prospective, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Study. Int J Mol Sci. 2019;20(4):856. Published 2019 Feb 16. doi:10.3390/ijms20040856
(4) McAlindon TE, LaValley MP, Harvey WF, et al. Effect of Intra-articular Triamcinolone vs Saline on Knee Cartilage Volume and Pain in Patients With Knee Osteoarthritis: A Randomized Clinical Trial. JAMA. 2017;317(19):1967–1975. doi:10.1001/jama.2017.5283
(5) Arias-Vázquez PI, Tovilla-Zárate CA, Legorreta-Ramírez BG3 Burad Fonz W, Magaña-Ricardez D, González-Castro TB, Juárez-Rojop IE, López-Narváez ML. Prolotherapy for knee osteoarthritis using hypertonic dextrose vs other interventional treatments: systematic review of clinical trials. Adv Rheumatol. 2019 Aug 19;59(1):39. doi: 10.1186/s42358-019-0083-7.
(6) Centeno C, Sheinkop M, Dodson E, et al. A specific protocol of autologous bone marrow concentrate and platelet products versus exercise therapy for symptomatic knee osteoarthritis: a randomized controlled trial with 2 year follow-up. J Transl Med. 2018;16(1):355. Published 2018 Dec 13. doi:10.1186/s12967-018-1736-8
(7) Okamoto T, Masuhara M, Ikuta K. Acute effects of self-myofascial release using a foam roller on arterial function. J Strength Cond Res. 2014 Jan;28(1):69-73. doi: 10.1519/JSC.0b013e31829480f5.
(8) Grawe B, Schroeder AJ, Kakazu R, Messer MS. Lateral Collateral Ligament Injury About the Knee: Anatomy, Evaluation, and Management. J Am Acad Orthop Surg. 2018 Mar 15;26(6):e120-e127. doi: 10.5435/JAAOS-D-16-00028.
(9) Sonnery-Cottet B, Daggett M, Fayard JM, et al. Anterolateral Ligament Expert Group consensus paper on the management of internal rotation and instability of the anterior cruciate ligament – deficient knee. J Orthop Traumatol. 2017;18(2):91–106. doi:10.1007/s10195-017-0449-8
(10) Centeno CJ, Schultz JR, Cheever M, Freeman M, Faulkner S, Robinson B, Hanson R. Safety and complications reporting update on the re-implantation of culture-expanded mesenchymal stem cells using autologous platelet lysate technique. Curr Stem Cell Res Ther. 2011 Dec;6(4):368-78. https://www.ncbi.nlm.nih.gov/pubmed/22023622
(11) Englund M, Guermazi A, Gale D, et al. Incidental meniscal findings on knee MRI in middle-aged and elderly persons. N Engl J Med. 2008;359(11):1108–1115. doi:10.1056/NEJMoa0800777
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