What is spondylolysis?

  • This injury occurs due to a stress fracture through part of a vertebra(e) known as the pars interarticularis of the lumbar vertebrae (located in the lower back). The pars interarticularis is a thin bone segment joining two vertebrae.

How common is spondylolysis?

  • This condition is common in the first two decades of life (1).
  • 20% more likely to occur in an active population of adolescents and young adults, particularly in sports that require repetitive rotation and extension (backwards bending) of the lower spine (4).
  • Stress fractures in the lumbar spine are present in 3%-10% of the adult population, but not all cause pain (3, 6, 9).
  • Up to 95% of stress fractures of the pars interarticularis occur at the junction between the lumbar and sacral spine (9).

Should I worry?

  • No.
  • When diagnosed in an appropriate time frame most stress fractures of the pars interarticularis can be managed without need for surgery (1,2).
  • Back pain in an adolescent lasting more than 2 weeks should be assessed by a physiotherapist (1, 8).

Who is most likely to suffer from spondylolysis?

  • Males are twice likely to suffer from this condition.
  • Those with a family history of low bone density.
  • More common in those aged below 25.
  • More common in Caucasians.
  • More common in sports where you arch your back such as tennis, gymnastics, dance, football and rugby.
  • Those who have had sudden increases in training load (returning to sport after injury, start of pre-season).

What are the common symptoms?

  • Pain onset that can be acute or gradual, after intense sporting activity (1).
  • Direct contact to that part of the spine (1).
  • Aching in the centre of the spine or just to the side.
  • Referral of pain into the buttock or back of the leg (5).
  • Morning stiffness that takes 30-60 minutes to settle.
  • Pain when arching the back backwards or twisting (6).
  • Rest usually relieves the symptoms (2).
  • Intense pain that restricts activities of daily living or sporting performance (6, 7).

What can I do?

  • Activity modification – initially this may mean total rest or using crutches, depending on the severity of injury (3).
  • Physiotherapy – after the initial period of rest, exercise can help strengthen the muscles around the spine (2).
  • Seek input from a musculoskeletal specialist who might suggest investigations and medication (2, 3).

How long will it take to recover?

  • This will depend upon several factors including, but not limited to, the severity of the injury and bone density (8).
  • Most stress fractures of the pars interarticularis take between 3-4 months to heal (2).
  • More severe cases can take 4-6 months to heal and return to sport (6).
  • In rare cases, if symptoms persist for 6 months without improvement with good conservative management, then referral for surgical opinion is warranted (1, 3, 8).

1. Introduction

Stress fractures of the pars interarticularis are defined as an injury to the bony bridge at the back of the vertebra which causes pain felt in the centre, or just off centre, of the lower back (1, 2) but can also cause pain in the buttock and back of the leg to the knee. This is often referred to as spondylolysis.

Each vertebra has two pars interarticularis, one on each side of the vertebra, and damage can occur on just one side or both (9). Symptoms can occur gradually over time or after a one-off movement (1, 6). Stress fractures of the pars interarticularis are present in around 5%-10% of the general population and are up to 20% higher in the athletic population under 20 (1, 2, 8).

There are different grades of injury:

All can cause pain and if pain is present for 2 weeks or more you should seek advice (1, 2, 3, 6).


2. Signs & Symptoms

3. Causes

This condition tends to affect young people in the first two decades of life (1, 3, 5). Activities that require extending the back (such as dance and gymnastics), twisting of the back (such as tennis or golf) or sports that require fast change of direction (such as football, rugby or basketball) (1, 6, 8) might contribute to the development of this condition. These activities place a lot of force across the bony bridge and can cause damage to the bone structure (8, 9).

As we grow and develop, our bones grow and our soft tissues, such as muscles and ligaments, adjust to this development. Due to this period of development our soft tissues are less efficient at supporting the spine in taking the load of activity and this causes our spine to take too much load around the pars interarticularis and cause injury (1, 6).


4. Risk Factors

This is not an exhaustive list. These factors could increase the likelihood of someone developing spondylolysis. It does not mean everyone with these risk factors will develop symptoms (1, 2, 3, 5, 7).


5. Prevalence

Stress fractures of the pars interarticularis are present in around 5%-10% of the general population and up to 12% of the athletic population under 20 (1, 2, 7, 8). Most of the injuries occur as a younger child and then become symptomatic as we continue to load the spine as an adolescent or young adult (3, 5, 7). After the age of 20, a new stress fracture of the pars interarticularis is significantly less likely.

6. Assessment & Diagnosis

Musculoskeletal physiotherapists and other appropriately qualified healthcare professionals can provide you with a diagnosis by obtaining a detailed history of your symptoms. A series of physical tests might be performed as part of your assessment to rule out other potentially involved structures and gain a greater understanding of your physical abilities to help facilitate an accurate working diagnosis.

Your treating clinician will want to know how your condition affects you day-to-day so that treatment can be tailored to your needs and personalised goals can be established. Intermittent reassessment will ascertain if you are making progress towards your goals and will allow appropriate adjustments to your treatment to be made.

Further investigations or imaging may include assessment of vitamin D levels; this is in the form of a blood test that will give an indication of bone health. If your symptoms have not resolved in sufficient time, you might be referred for further investigations such as X-ray, magnetic resonance imaging (MRI) or CT Scan to get a definitive diagnosis of the problem and help to decide the best treatment options. If you have had previous stress fractures and another one is suspected, you may be sent for a DEXA (dual energy X-ray absorptiometry) scan that will give an indication of your overall bone health.

7. Self-Management

Initial self-management includes activity modification and resting from aggravating activities for two weeks. If pain settles, then gently resume exercise. If pain returns or never subsides, seek further assessment from a musculoskeletal specialist.

As part of the sessions with your physiotherapist, they will help you to understand your condition and what you need to do to help the recovery from your spondylolysis. This may include reducing the amount or type of activity, as well as other advice aimed at reducing your pain. It is important that you try and complete the exercises you are provided as regularly as possible to help with your recovery. Rehabilitation exercises are not always a quick fix, but if done consistently over weeks and months then they will, in most cases, make a significant difference.


8. Rehabilitation

This will depend entirely on your symptoms and the outcome of any imaging that may be requested.

For all grades of injury your physiotherapist will work with you to progress toward your goals of rehabilitation that you have agreed. Below are three rehabilitation programmes created by our specialist physiotherapists targeted at addressing stress fractures of the pars interarticularis. In some instances, a one-to-one assessment is appropriate to individually tailor targeted rehabilitation. However, these programmes provide an excellent starting point as well as clearly highlighting exercise progression.

9. Spondylolysis Rehabilitation Plans

Early Plan

This programme will begin the process of increasing the strength of the muscles around the lower back, abdomen and pelvis. It should be performed regularly as the level of exercise is quite light. This should not exceed any more than 3/10 on your perceived pain scale.

Early Plan - Rating

Intermediate Plan

Here the exercises progress to more challenging positions and increased effort level. This is with the aim of increasing the strength in the area. This should not exceed any more than 3/10 on your perceived pain scale.

Intermediate Plan - Rating

Advanced Plan

In this stage, we add more challenging exercises and more whole-body movements to further increase strength and to prepare the back towards a return to normal activity. This should not exceed any more than 3/10 on your perceived pain scale.

Advanced Plan - Rating

10. Return to Sport/Normal Life

Returning to sport after stress fracture of the pars interarticularis is a gradual process of slowly increasing the difficulty of strengthening exercises and reintroduction to preferred sporting activities (1, 3, 8).

For patients wanting to achieve a high level of function or return to sport, we would encourage a consultation with a physiotherapist as you will likely require further progression beyond the advanced rehabilitation stage.

As part of a comprehensive treatment approach, your musculoskeletal physiotherapist may also use a variety of other pain-relieving treatments to support symptom relief and recovery. Whilst recovering you might benefit from further assessment to ensure you are making progress and establish appropriate progression of treatment. Ongoing support and advice will allow you to self-manage and prevent future reoccurrence (1, 6, 8).

A small percentage of adolescents and young adults do no heal and if, after 6 months of appropriate conservative management, things are not improving, you may be referred to a specialist orthopaedic consultant where surgery may be considered (1, 5).

11. Other Treatment Options

Specific treatment methods such as some electrotherapies and supplements, such as vitamin D, have been found to help with the healing process and may be included in your rehabilitation if appropriate.

For those who do not recover with activity modification, exercises and other comprehensive treatments, the next option is often surgical (1, 6, 8).

  • Surgical pinning – here a small incision is made in the back and using a live CT scan of the lumbar spine a screw is placed across the fracture site to bring the two bone ends together. A special protein is then injected around the fracture site that stimulates the bone to heal (6).
  • Bisphosphonates – a medication that helps suppress the cells in the body that reabsorb bone, thus providing a good environment within the bone for healing. They can have associated side-effects so it is worth reading up on them before deciding to use them.

Book and Appointment

Please book an appointment with one of our physiotherapists if you think you are suffering from this condition and would like to find out more.

We have Pure Physiotherapy clinics across the country including Norwich, Great Yarmouth, Manchester, Stockport, Sheffield and Rotherham. Please view our clinics to find the closest physiotherapy clinic for you.


  1. Astur, D.C., Zanatta, F., Arliani, G.G., Moraes, E.R., Pochini, A.D.C. & Ejnisman, B. (2016). Stress fractures: definition, diagnosis and treatment. Revista brasileira de ortopedia, 51(1), 3-10.
  2. Leone, A., Cianfoni, A., Cerase, A., Magarelli, N. & Bonomo, L. (2011). Lumbar spondylolysis: a review. Skeletal radiology, 40(6), 683-700.
  3. Ruiz-Cotorro, A., Balius-Matas, R., Estruch-Massana, A.E. & Angulo, J.V. (2006). Spondylolysis in young tennis players. British journal of sports medicine, 40(5), 441-446.
  4. Field, A.E., Gordon, C.M., Pierce, L.M., Ramappa, A. & Kocher, M.S. (2011). Prospective study of physical activity and risk of developing a stress fracture among preadolescent and adolescent girls. Archives of paediatrics & adolescent medicine, 165(8), 723-728.
  5. Cavalier, R., Herman, M.J., Cheung, E.V. & Pizzutillo, P.D. (2006). Spondylolysis and spondylolisthesis in children and adolescents: I. Diagnosis, natural history, and nonsurgical management. JAAOS-Journal of the American Academy of Orthopaedic Surgeons, 14(7), 417-424.
  6. Robberecht J. Stevens N. & Sys J. (2016). Treatment of Acute Spondylolysis in elite Athletes. Literature Review and Presentation of a new Percutaneous Grafting Technique Open Access Journal of Neurology and Neurosurgery, 1(4), 1-6.
  7. Depalma M. (2011). iSpine: Evidence-based interventional spine care, Demos Medical Publishing p. 156-157. (Level of evidence: 5).
  8. Haun D. & Kettner N. (2005). Spondylolysis and spondylolisthesis: a narrative review of etiology, diagnosis, and conservative management. Journal of chiropractic medicine 4(4): 206–217 https://doi.org/10.1016/S0899-3467(07)60153-0.
  9. Ruff, A.N., Cornelson, S.M., Wells, C.B. & Kettner, N.W. (2019). Neural Arch Bone Marrow Edema and Spondylolysis in Adolescent Cheerleaders: A Case Series. Journal of Chiropractic Medicine, 18(4), 335-342.
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