Pars Defect: What it Means and What to Do About it

Pars defect

Pars defect describes a crack or fracture in your pars interarticularis which is a small connecting bone in your lower spine. A defect in the pars interarticularis is a common cause of lower back pain and can result in pain when walking and stiffness in the lumbar region. A pars defect can also cause radiated pain in the buttock, thighs, or the backs of your legs.

Pars defect is closely connected with two conditions that cause pain in the lower back – spondylolysis and spondylolisthesis. These painful lower back conditions can be the result of overusing the lower back, trauma when playing sports or due to genetic factors.

Usually, to help ease the pain that pars defect causes, doctors recommend a course of physical therapy. This is to relax the muscles and strengthen the core and lower back area. Very often, heat compresses applied to the lower back can help to alleviate lumbar pain and increase flexibility. Strengthening the back muscles and using a correct posture are usually the best ways to prevent pain and discomfort caused by pars defect.

This article looks at the many causes of pars defect and how you can treat symptoms of spondylolysis and spondylolisthesis. First of all, it’s important to know something about the anatomy of your lower spine.

The Anatomy of Your Lower Spine

The area of your lower spine is generally referred to as your lumbar area. The bottom of your spine contains 5 lumbar vertebrae which are numbered one to five: from L1, which starts around your middle back, to L5, which connects to your sacrum (the triangular-shaped bone between your hip bones).

Dr. Stephen Kishner on Medscape says that your lumbar spine contains large muscles, ligaments, tendons, vertebrae, and sensitive nerves. These elements provide strength to your body and allow the body to move, bend, and pivot freely.1

Your pars interarticularis (or, just pars for short) is a small piece of bone at the base of your spine where L4 and L5 vertebrae are located. Any defect of the pars interarticularis will cause stiffness, pain, and severe discomfort in your lumbar area. This could be due to trapped nerves, muscle soreness, or inflammation.1

Spondylolysis vs. Spondylolisthesis

Very often, when searching for painful conditions that affect the lower back and are connected with pars defect, you will come across spondylolysis and spondylolisthesis. You will probably have spondylolysis or spondylolisthesis if you damage your pars interarticularis. Although these lumbar conditions cause similar symptoms, there is a difference between them.


Spondylolysis is a stress fracture that commonly occurs in the pars interarticularis at the L5 vertebra. According to the Asian Spine Journal, spondylolysis is a common cause of lower back pain. This is a common condition among sports people or individuals who frequently lift heavy items.2


Dr. William Blahd on WebMD says that spondylolisthesis occurs when a vertebra slides forward over the bone below it. This is usually the L4 or L5 lumbar vertebra that slips out and pushes on the bone below. This can be caused by joint damage from aging or a trauma.

Spondylolisthesis often causes pain in the lower back area and pain and numbness in one or both legs.3 You may also suffer from sciatic pain (pain radiating down one or both legs).

According to Dr. Gerard Malanga from New Jersey Sports Medicine, spondylolisthesis commonly happens when the L5 vertebra slips forward and presses on the sacrum causing pain and discomfort.4

Causes of Pars Defect

Let’s look in more detail at various conditions that can cause a pars defect. This will also help you know what to do about a defect in the pars interarticularis and how to avoid putting more strain on your lower back.

Stress fractures

Stress fractures in the L4 or L5 vertebrae are the most common reason for pars defect that can also lead to spondylolysis and spondylolisthesis.

According to Dr. Sally Harris from the Palo Alto Medical Foundation, pars stress fractures are often the result of repetitive stress and overuse. This can result in the pars bone weakening so much that a crack develops or it breaks completely.5

Dr. David Green from the Hospital for Special Surgery reports that pars stress fractures can result in spondylolysis on one side of the spine or both sides. Bilateral spondylolysis can result in the L5 vertebra becoming so weakened that it slips forward and causes spondylolisthesis.6

To diagnose stress fractures in the vertebrae of the lower back, doctors sometimes perform a one-legged hyperextension test. The British Journal of Sports Medicine reports that this test involves the patient standing on one leg then leans backward to see if any lumbar pain is felt. However, the best way to confirm pars defect is an MRI scan.7

Researchers from the Cleveland Clinic say that physical therapy and exercise can help to strengthen core muscle and prevent L4 or L5 stress fracture issues. This helps to support the lower back better and improves flexibility.8

Muscular problems

Straining muscles in your lower back can put extra pressure on your lower spine and eventually lead to a pars defect.

According to doctors from the American Academy of Orthopedic Surgeons, spondylolysis and spondylolisthesis can show symptoms of lower back muscle weakness and spasms. Usually, if this is the case, doctors will recommend physical therapy to stretch tight hamstring muscles and strengthen core muscles.9

Degenerated discs

Aging and arthritis can cause a pars defect as discs and vertebrae in the lower back become weaker and dry out.

Doctors from the American Academy of Orthopedic Surgeons say that pars fractures in adolescence may not show any symptoms until later on in adulthood. Wear and tear on your lower back as well as inflammation can cause vertebrae in the lower spine to slip forward and press on nerves in your lower back. This results in great discomfort and lumbar pain.10

If wear and tear have affected your L4 and L5 vertebrae, you may also develop leg weakness after standing or walking for a long time. It is also possible that you have tingling or pain in your legs.

Herniated disc

A herniated disc between your L4 and L5 vertebrae can cause shooting pains in your lower back and cause a defect in your pars interarticularis.

Spinal discs are small jelly-like discs that act as “cushions” between the vertebrae in your spine. Doctors from the Mayo Clinic says that a herniated or ruptured disc happens when the “jelly” pushes out of the disc membrane. This results in pain and weakness in your lower back when a herniated disc occurs in your lumbar vertebrae.11

The journal European Review for Medical and Pharmacological Sciences reports that a herniated disc can be associated with pars defect. It was found that spondylolysis can put extra pressure on the lumbar spine and increase the load on the spinal discs.12

Sacroiliac joint dysfunction

Related to pars defect and lower back pain is sacroiliac joint dysfunction.

The sacroiliac joint is between your sacrum – the large bone at the base of your spine – and your hip bones. The last vertebra (L5) at the base of your spine connects to the sacrum. Because sacroiliac joint dysfunction and pars defect can cause similar symptoms, it can be difficult to distinguish between the two.

According to the journal ClinicoEconomics and Outcomes Research, dysfunction in the sacroiliac joints should also be considered as a cause of chronic lumbar pain.13

Symptoms of L4-L5 Pars Defect

A pars defect of the L4 and L5 vertebrae often causes lower back pain that can become chronic and difficult to treat. However, not everyone who suffers from pars defect has painful symptoms.

Doctors from the American Academy of Orthopedic Surgeons report that the most common symptom of pars defect is lower back pain. Depending on the extent of the pars defect and if there are symptoms of spondylolysis, you may also experience pain that is felt in your upper thigh or buttocks.9

If pars defect has caused the L5 vertebra to slip, you will usually experience pain and discomfort in your lower back and other symptoms of spondylolisthesis. Expert in arthritis and rheumatic diseases, Dr. Catherine Burt Driver says that the common symptoms of spondylolisthesis are tight hamstring muscles, weakness in the legs, and stiffness in the lower back.

Home Remedy Treatments for Pars Defect

Treating pars defect usually involves managing the pain with pain relief treatments and physical therapy. If you are looking for ways to treat chronic low back pain caused by a defect in pars interarticularis, here are some of the best home treatments for lumbar pars defect.

Warm compress

A warm compress on your lumbar area can help to relieve chronic pain caused by pars defect.

Heat from a compress helps to increase blood circulation to the painful area in your lower back and also relaxes the nerves and muscles. In fact, Dr. Catherine Driver says that warm compresses can help get rid of back pain caused by spondylosis.15

How to make a warm compress at home for pars defect pain

It is very easy to make a warm compress to help soothe lower back pain caused by pars defect. This is what you should do:

  1. Take a clean cotton sock and fill it with dry rice, leaving about 3 inches clear at the top.
  2. Tie the end of the sock in a knot or use a piece of string to tie it shut.
  3. Microwave the sock on full power for 1-2 minutes.
  4. Wrap the sock in a damp hot washcloth and place on your lower back just above your buttocks.
  5. Leave for 15-20 minutes to relieve lumbar pain.
  6. If necessary, you can put the compress back into the microwave and reheat for up to 1 minute.
  7. Use whenever you need to get rid of pain caused by L4 or L5 pars defect.

Physical therapy

For many sufferers of chronic low back pain, physical therapy is the best way to alleviate the discomfort that spondylolysis or spondylolisthesis cause.

According to the Journal of Chiropractic Medicine, a course of physical therapy can help to manage lower back pain. Researchers have found that physical therapy techniques are some of the best ways to treat L4 and L5 pars defect, even if the severity of the defect was classed as a high-grade fracture.16

The Journal of Bodywork and Movement Therapies also found that treatment by a physical therapist can help to reduce pain and restore movement in the lumbar region caused by spondylolisthesis.17

To know what type of exercises are the most beneficial to reduce lower back pain, you should visit a qualified physical therapist. You can also try some of my great exercises to do at home to strengthen your back and get rid of back pain. Some of these include using a tennis ball to relieve lumbar pain and doing foam roller exercises for back pain.

Natural ways to manage lower back pain

There are also many excellent effective home remedies that you can use to help manage chronic back pain caused by pars defect. Here are some of the most effective natural pain relieving remedies you can try at home.

Turmeric. Turmeric is one of the best spices to help get rid of joint pain and reduce inflammation. Turmeric supplements containing piperine can help to manage chronic pain that arthritis or other degenerative conditions cause. For example, the journal Springerplus reported that studies into curcumin (the main compound in turmeric) have shown to be beneficial in treating pain caused by inflammatory joint conditions.18

Ginger. Ginger is closely related to turmeric and also has anti-inflammatory and analgesic properties. A study in the journal Arthritis and Rheumatism reported that ginger supplements help to reduce symptoms of osteoarthritis like joint pain.19

Before taking ginger or turmeric supplements for lower back pain, please read my articles about why ginger should be avoided by some people and turmeric should be avoided by these people.

Essential oils. Many essential oils help to relieve pain, relax muscles, and improve blood flow to the lower back area. For example, lavender essential oil has been shown to contain anti-inflammatory properties that can help manage joint pain. Other great essential oils to relieve tension in joints include chamomile essential oil, eucalyptus oil, sandalwood, and ginger oil.

How Long Does Par Defect Take to Heal?

Depending on the extent of the pars defect, it could take up to 2 months to heal completely.

Doctors from the Palo Alto Medical Foundation say that healing a pars defect or pars fracture requires plenty of rest and time. Usually, treatment involves 2 months of graded physical therapy to repair most of the damage in the lower back.5

Other physiotherapists say that, depending on your symptoms, it can take 6 to 12 weeks to resolve the pain and help prevent a recurrence.

How to Prevent Pars Defect

According to clinical physiotherapist John Miller, the best way to prevent pars defect is to avoid overstressing your lower back. This requires learning how to move properly and also strengthening your abdominal and lower back muscles.20

Proper posture to prevent pars defect symptoms

One easy way to prevent pars defect symptoms is to learn proper posture. Dr. Gerard Malanga on Medscape says that correct posture is essential to prevent putting extra strain on your lumbar spine and protect the injured pars.21

For easy ways to improve your posture, please read my article on how to exercise to get a better posture. For example, learning how to sit to avoid back pain is essential if you have pars defect. Plank exercises also help to improve posture by strengthening your core muscles.

Strengthen core muscles

Dr. Michael Smith on WebMD says that you can ease back pain by strengthening your core muscles. For example, strengthening your glutes can help to stabilize the lower back and prevent pain.22 You can also find some excellent core-strengthening exercises on this website.

When to See a Doctor for Lower Back Pain

Usually, with proper rest and using effective home remedies for back pain, the discomfort in your lumbar region caused by a pars defect should go in a few weeks.

However, doctors from the Mayo Clinic advise that in some circumstances you should see a doctor for low back pain.23 These include:

  • Back pain that is constant or intense pain that is worse at night or when lying down.
  • The pain from your lower back spreads down one or both legs to your hamstrings, calf muscles or ankles.
  • You experience tingling or weakness in one or both legs.
  • You also notice swelling or redness on your back.
  • Along with the intense back pain, you also have bowel or bladder control problems.

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Article Sources

  1. Medscape. Lumbar spine anatomy.
  2. Asian Spine J. 2014 Dec; 8(6): 856–863.
  3. WebMD. Spondylolisthesis.
  4. Medscape. Pars interarticularis injury.
  5. PAMF. Pars stress fractures of the lumbar spine.
  6. HSS. Spondylolysis.
  7. Br J Sports Med. 2006 Nov; 40(11): 940–946.
  8. ClevelandClinic. Spondylolysis.
  9. AAOS. Spondylolysis and spondylolisthesis.
  10. AAOS. Adult spondylolisthesis in the low back.
  11. MayoClinic. Herniated disk.
  12. Eur Rev Med Pharmacol Sci.2012 Nov;16(13):1859-65.
  13. Clinicoecon Outcomes Res. 2016; 8: 23–31.
  14. MedicineNet. Spondylolisthesis.
  15. eMedicineNet. Spondylosis.
  16. J Chiropr Med. 2009 Sep; 8(3): 125–130.
  17. J Bodyw Mov Ther.2016 Jul;20(3):554-64.
  18. Springerplus. 2013; 2: 56.
  19. Arthritis Rheum.2001 Nov;44(11):2531-8.
  20. PhsioWorks. Spondylolysis.
  21. Medscape. Pars interarticularis injury treatment & management
  22. WebMD. Relieve back pain with core strength training.
  23. MayoClinic. Back pain: symptom.

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