Knee Pain

Knee Pain

Almost everyone has had knee pain.  Knee pain is one of the most common reasons people come to see me in sports medicine.  This article will review the most common causes of knee pain, important information about each, and recommended treatment.

Causes of Knee Pain

  1. Runner’s Knee (Patellofemoral Pain Syndrome)
  2. Jumper’s Knee (Patellar Tendonitis)
  3. Osteoarthritis
  4. Knee Cap (Patellar) Laxity
  5. Patellar tendon pulling bone (Osgood Schlater’s or Sindig-Larson-Johansen)
  6. Pes Anserine Bursitis
  7. Acute Injuries
    • Ligament sprain (ACL, MCL, IT Band, etc.)
    • Acute tendon strain (quad, patellar, hamstring)
    • Meniscal tear
  8. Others

Knee pain exam

Knee Pain Stats

  • Affects approximately 25% of adults
  • Knee pain prevalence has increased 65% over the past 20 years
  • Causes 4 million primary care visits per year
  • Knee symptoms are the 10th most common reason for outpatient visits
  • Recent studies support NO SURGERY for common knee diseases, such as osteoarthritis and meniscal disease because of poor outcomes
  • History is essential and will often lead to a diagnosis
  • X-rays whenever a fracture is suspected, for sprains (ACL, MCL, PCL), patellar dislocations, and meniscal injuries

Runners sports medicine

Runner’s Knee

  • The most common cause of knee pain in the front, especially in women
  • Pain is often described as deep, behind the knee cap
  • Worsened by running, jumping, deep squats, lunges, going up or down stairs
  • Knee pain also worsened after prolonged periods of sitting (the “theater sign”)
  • Symptoms: swelling, knee creaking with motion
  • Pain reproduced by applying direct pressure at the front of the knee cap
  • Tenderness also reproduced by pushing around the knee cap or actually moving the kneecap around
  • X-rays, MRI, and other imaging are NOT indicated
  • Caused By:

    • Poor tracking of the knee cap – think of your knee cap as a race car in a race track, with runner’s knee your race car driver is drink and hitting the side walls of your race track
    • Weak gluteus muscles – Butt muscles stabilize your hip and in turn stabilize your knee. Weakness is due to sitting on our butts too much.  Try a one-legged squat, if you are wobbly or your leg makes an L shape then start doing butt crunches
    • IT Band tightness – the IT band partially attaches to the outside edge of the knee cap, so if it’s tight it pulls the knee cap out and off track
  • Treatment:

    • Physical therapy – Studies show quadriceps and hip strengthening combined with stretching of quadriceps, hamstrings, hip flexors, and iliotibial band three times weekly for six to eight weeks is effective in reducing pain and improving functionality.
    • Weight loss – less weight means less pressure and force on knees
    • Glut strengthening: butt muscles control the stability of the knee and people end up sitting on them for most of the day, they weaken and cause knocked-knees, especially when doing activities (running, jumping, lunges, etc.)
    • NSAIDs (Motrin, Aleve, Ibuprofen, Celebrex, Mobic, topical creams etc.) are effective for short-term relief of pain

shoes and dumbbells

Jumper’s Knee

  • Pain, irritation, and inflammation of the patellar tendon usually seen with jumping sports (volleyball, basketball)
  • Most commonly occurs in teenage boys, particularly during a growth spurt
  • Patients report vague anterior knee pain that persists for months and worsens after activities such as walking down stairs, jumping, or running.
  • Tenderness on the patellar tendon (connects your knee cap to your lower leg)
  • Pain is reproduced by resisting a kicking motion
  • There is usually no swelling
  • X-rays are NOT indicated.
  • Caused By:
    • Overuse of the tendon that connects from your knee cap to your lower leg.  It’s basically how your quad muscles connect to your lower leg.
  • Treatment:
    • Acute pain relief with Tylenol and NSAIDs
    • Physical therapy
    • Lengthening Exercises (eccentrics)
    • Temporarily Resting from jumping activities

knee x-ray



  • Common after 60 years of age
  • Morning stiffness that gets better with activity
  • Knee pain worsened by prolonged periods of rest and inactivity
  • Chronic joint stiffness and pain, with acute periods of worsening and pain
  • Physical examination with decreased range of motion, creaking, joint swelling, and palpable joint spurs.
  • Plain X-rays will confirm diagnosis with joint space narrowing, wearing down of the joint, cysts, and bone spurs.
  • Caused by:

    • Age – more living means more wear and tear on your joints
    • Obesity/Overweight – more weight causes more pressure on your joints
    • Jumping out of airplanes – activities with a lot of repetitive jarring of the knees will cause early arthritis of the knees
  • Treatment:

    • Tylenol and NSAIDs (Motrin, Aleve, Ibuprofen, Celebrex, Mobic, topical creams etc.) are first-line treatments for arthritis
    • Exercise – more activity means keeping your joints moving and better lubricated.  I recommend non-impact activities like bicycling, swimming, elliptical
    • Physical therapy – For strengthening and stabilization of the knee
    • Weight loss – less weight means less pressure and force on knees
    • Injections – I do a lot of knee injections.  Mostly steroids (anti-inflammatory) and hyaluronic acid (Synvisc- a synthetic version of a naturally occurring joint lubrication).  There is also pretty good evidence for a Platelet Rich Plasma (PRP) injections.  There is NO good research to support stem cell injections, yet, but these are now available as well.
    • Knee Replacement – They last only 15-20 years, so the goal is to try to prevent knee replacement with alternative options as much as possible until after age 70+.  Plus it’s a big surgery, I advise patients to weigh the risks and benefits before deciding.
    • Glucosamine/chondroitin supplements show mixed benefit and are not recommended by the American Academy of Orthopedic Surgeons.  However these supplements have minimal side effects and if they work for you personally then I always recommend continuing them.
    • Knee braces – Very small evidence exists for pain relief with a very specific and expensive unloader brace.  Studies for most braces show no benefit.


Medial unloader braces shown to have minimal benefit


These knee braces have NOT been shown to help knee pain.  Knee braces in general can be harmful because of the weakness they facilitate.

Knee Cap (Patellar) Laxity

  • Comes in the form of dislocations, subluxations (almost dislocations), looseness
  • Occurs more often in girls and young women because of our wider hips
  • Discomfort and apprehension is caused by pushing the kneecap out-of-place toward the IT Band
  • Mild swelling is usually present after the kneecap dislocates or almost dislocate
  • Severe knee swelling may indicate blood in the joint, which suggests dislocation with cartilage damage
  • X-rays are necessary to look for fractures
  • Caused by:
    • Loose ligaments around the kneecap, often people are just born with extra knee cap movement
    • Muscle weakness, which results in poor knee cap stabilization
  • Treatment:
    • Physical therapy to stabilize and prevent recurrent episodes
    • Acute pain relief with NSAIDs and Tylenol
    • Special knee cap taping may help with stabilization
    • Knee braces when active may help.  They have specialized braces with knee cap stabilizers built-in.
    • Risk of recurrence is increased in younger people
    • There are surgical interventions (ligament reconstruction) for people who dislocate often and all other treatment options have failed

Patellar stabilization braces when active may help prevent subluxations/dislocations.

Patellar Tendon Pulling Bone (Apophysitis)

  • Also known as Osgood-Schlatter disease when at the end of the patellar tendon or Sindig-Larson-Johansson when at the top of the patellar tendon (at the bottom of the knee cap).
  • The typical patient is a 13- or 14-year-old boy (or a 10- or 11-year-old girl) who has recently gone through a growth spurt
  • Patients with Osgood-Schlatter generally report waxing and waning knee pain for months
  • Pain worsens with squatting, walking up or down stairs, or forceful contractions of the quads.
  • Exacerbated by jumping and hurdling.
  • On exam there will be a tender and swollen lump at the top of the shin bone that may feel warm.
  • There is no swelling
  • X-rays are usually negative; rarely, they show the tendon pulling at the bone
  • Caused By:
    • Repetitive hard landings place excessive stress on where the patellar tendon connects to bone.
  • Treatment:
    • NSAIDs or Tylenol as needed for acute pain
    • Relative rest
    • Usually pain stops on its own as the growth plates close

fallen athlete


Pes Anserine Bursitis

  • Inflammation of a bursa below the knee joint line toward the inside, where 3 muscles connect to the lower leg
  • It can be confused easily with a ligament sprain or osteoarthritis of the inside of the knee
  • Tenderness at the location of the bursa.
  • The bursa itself may be slightly swollen without knee joint swelling
  • X-rays are usually not indicated.
  • Caused By:
    • Bursa inflammation as a result of overuse or a direct blow.
  • Treatment:
    • Acute pain relief with NSAIDs and Tylenol
    • Steroid injection (6+ weeks relief)
    • Physical therapy for stretching and strengthening.  A comprehensive and individualized rehabilitation program is the best.

Knee Pain Meniscus

Acute Injuries

  • Ligament sprain (ACL, MCL, IT Band, etc.) and Acute tendon strain (quad, patellar, hamstring)

    • Knee swelling after traumatic ligament sprain usually occurs immediately and is bloody
    • Knee will feel unstable after sprain
    • Patient often has to stop activity immediately due to pain and instability
    • There will be pain and tenderness on top of the actual structure injured
    • History concerning for an ACL injury is a twist with a pop and swelling
    • Complete tendon tears will result in profound weakness and sometimes a bulge where the muscle has retracted.
    • X-rays and MRI are indicated for suspected complete ACL or any complete tendon tears
    • Isolated MCL or PCL tears get an x-ray and do not need an MRI
    • Caused By:
      • Acute injury by stretching or tearing of the ligament or tendon
    • Treatment:
      • NSAIDs and Tylenol for pain
      • Ice immediately to help with swelling
      • Physical therapy for strengthening and stabilization, and to restore range of motion
      • PT is especially important prior to ACL repair as it improves outcomes after surgery
      • Surgery is indicated for complete ACL tears and complete tendon tears/ruptures
      • PCL sprains and tears or partial tendon strains do not need surgery
      • If you suspect a complete ACL or complete tendon tear then I recommend that you see your health care provider as these will often require surgery
  • Meniscal tear

    • Acute meniscus tears can occur with sudden twisting of the knee, like when a runner suddenly changes direction.
    • Meniscal tears also may occur over time, like with osteoarthritis, or a missing ACL
    • Knee pain is reported with episodes of catching or locking, especially with squatting or twisting
    • Tenderness is along the joint line.
    • Standing on one leg and twisting causes pain
    • X-rays are usually negative and are seldom indicated
    • MRI is the radiologic test of choice because it demonstrates most significant meniscal tears and is recommended only after physical therapy and other non-surgical options have failed
    • Knee swelling is delayed, usually until the next day after the injury
    • Treatment:
      • Physical therapy (PT)
      • Active rehabilitation (PT) has the SAME outcomes as surgical treatment, with improved pain and function in patients (isn’t it awful, they actually did FAKE surgery on a large number of people to prove that real surgery didn’t make a difference)
      • Surgery recommended only with severe symptoms of locking and catching that persists after PT

medication and needles


I definitely have simplified the causes of knee pain above into the most common.  This list has also skipped over the more systemic causes of knee and joint pain, like gout and rheumatoid arthritis, because they usually occur in multiple joints, not just the knees.  There are other causes of course, so if your knee pain is severe or doesn’t fit into any of these categories then please see your health care provider.  You should also go to a medical professional for any children with knee pain because their bones are still maturing, they often have referred pain, and their treatment is more conservative.

I recommend a sports medicine doc like me, but family physicians are also well trained in musculoskeletal injuries and a lot of times you really just need some dedicated physical therapy to fix the muscle weakness or imbalances that are causing your pain.  In other words lack of exercise is one of the most common contributing causes of knee pain, so aside from physical therapy one of the most important recommendations I give for knee pain is alternative physical activity.  I usually prescribe yoga and pilates to get you lean and strong, while stretching out your muscles.  Swimming, biking, and elliptical are great activities to keep you moving without a lot of knee impact.  Exercise allows for strengthening and weight loss.


Who Needs an Orthopedic Surgeon Referral?

  • Knee cap that doesn’t go back in place
  • Any fractures
  • Recurrent knee cap dislocation with high level activity, if continuing high level sport/activity
  • Meniscal tears on MRI that are causing locking/catching or persistent bad symptoms even after a trial of PT, NSAIDs, rest, and activity modification
  • Complete ACL or tendon tears for repair
  • PCL tears only if there is also another ligament or meniscal injury

knee Arthroscopy


Please let me know if you have any questions.  You can also reach me through Facebook or Instagram through the follow me links under my bio.



  1. Nguyen US, Zhang Y, Zhu Y, Niu J, Zhang B, Felson DT. Increasing prevalence of knee pain and symptomatic knee osteoarthritis: survey and cohort data. Ann Intern Med. 2011;155(11):725–732.
  2. Cherry DK, Woodwell DA, Rechtsteiner EA; Centers for Disease Control and Prevention. National Ambulatory Medical Care Survey: 2005 summary. Accessed Nov 4, 2017.

  3. Buchbinder R, Richards B, Harris I. Knee osteoarthritis and role for surgical intervention: lessons learned from randomized clinical trials and population-based cohorts. Curr Opin Rheumatol. 2014;26(2):138–144.

  4. Calmbach WL, Hutchens M. Evaluation of patients presenting with knee pain: part I. History, physical examination, radiographs, and laboratory tests. Am Fam Physician. 2003;68:907–12.

  5. Calmbach WL, Hutchens M. Evaluation of patients presenting with knee pain: part II. Differentail Diagnosis. Am Fam Physician. 2003 Sep 1;68(5):917-922.


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