One of the greatest joys as a parent is watching our children compete in sports they love.
Sports like football, baseball, volleyball, gymnastics, wrestling, dance can be very physically
demanding with countless hours of practice that helps build character and shape their future.
Unfortunately, some will experience low back pain that will limit their performance and keep
them out of the competition, leaving you as parents searching for answers.
A commonly overlooked cause of back pain in teenage athletes is a pars fracture, also known as
spondylolysis. This stress fracture in the lower back develops due to chronic wear and tear
from physical sports activities that require repetitive motion – twisting, bending and
hyperextension (backwards bending of spine). When recognized and diagnoses early, many
pars fractures can heal with bracing and activity modification. However, delayed diagnosis can
lead to progression of the injury into a chronic nonunion of the bone and chronic pain, that can
result in requiring surgery.
Our comprehensive guide will help you understand what a pars fracture is, how it causes your
young athlete’s back pain, how it is diagnosed, and the nonsurgical treatment options and
minimally invasive surgical pars repairs available. Our goal is to provide education and
knowledge that will help you as a parent make an informed decision for your child’s safe return
to competitive sports and activities they love.
A pars fracture, medically called spondylolysis, is a small defect or stress fracture of the bone
called pars interarticularis. This bridge of bone connects upper and lower facet joints of a
vertebra. This condition is most common as a lumbar stress fracture in young adolescent
athletes complaining of low back pain.
Pars defects and fractures are most common in teenagers and young adult athletes who
participate in sports requiring repetitive bending backward (lumbar hyperextension) and
twisting (rotation) of the lower back, such as gymnastics, football, wrestling, diving,
weightlifting, baseball and softball pitchers and competitive dance. These repetitive
movements place significant stress on the pars interarticularis, leading to stress fractures over
time. Approximately 80–90% of pars defects occur at the L5 vertebra, the lowest lumbar
vertebra, because it experiences the greatest mechanical stress. While pars fractures affect
approximately 4–6% of the general population, they are found in 15–30% of adolescent
athletes participating in high-risk sports. In adults, pars defects are often the result of an injury
sustained during adolescence that never fully healed and may later become symptomatic due
to age-related degeneration or progression to spondylolisthesis.
Pars interarticularis fracture, also called pars fracture or spondylolysis, presents most
commonly in adolescent athletes with persistent lower back pain. A stress fracture in the low
back develops with repetitive bending and rotational stress instead of a single traumatic injury.
Many young athletes dismiss the low back pain as a muscle strain. However, the pars fracture
produces progressive pain development with continued sports activity.
Signs include:
Unlike a herniated disc, pars fracture (spondylolysis) usually does not include any radicular leg
pain, numbness or weakness unless another spinal condition is present.
Pars fracture is a type of stress fracture in the lower back that results from repetitive forces on
the spine. In young athletes, the small bridge bone called pars interarticularis is subject to
repeated mechanical stress during athletic training and competition. Over time, these repetitive
forces can develop tiny, microscopic cracks or defects and eventually progress to a stress
fracture if the bone does not heal.
The lumbar spine absorbs tremendous forces, especially the L5 vertebra, during athletic
activity. The pars interarticularis serves as a stabilizing bridge between the facet joints and the
vertebra. When athletes perform repeated movements, without proper rest and time, the bone
takes on stress that sometimes can exceed the ability of the bone to repair itself.
The primary biomechanical forces that contribute to lumbar pars fracture include:
Unlike a single accident of a broken bone, a stress fracture can progress gradually. Each
training session, practice, or competition can create a microscopic injury to the pars bone.
Under normal routine conditions, the body repairs this damage with proper rest periods.
However, when athletes continue high intensity training and competition without enough time
to rest, the damage can accumulate faster than bone can rebuild and repair itself. Over time
these small defects merge into a pars fracture, resulting in persistent athlete back pain that
worsens with activity and sometimes improves with rest.
Early recognition and prompt diagnosis of many cases of spondylolysis, by a qualified spine
surgeon, can heal successfully with activity modification, physical therapy and appropriate
treatment.
Diagnosing a pars fracture (known as a spondylolysis or interarticularis fracture) begins with an
evaluation by a spine specialist.
Many teen athletes assume their low back pain is “just soreness” from competition and
training. Unfortunately, a pars fracture can hide behind these minor symptoms. The sooner
persistent back pain is evaluated, the greater chance of healing the injury without surgery and
returning safely to the sports they love.
A spine specialist’s diagnosis starts with a medical history and thorough physical examination.
The back surgeon begins with asking the following questions regarding history and your
symptoms:
Physical Exam –
Physical exams can strongly suggest a lumbar pars fracture and image studies can confirm the
diagnosis. The following image studies are used by the spine specialist:
When a pars fracture (spondylolysis) is suspected, X-rays are typically the first imaging study
ordered. While X-rays cannot detect every pars fracture, they provide important information
about the alignment and stability of the lumbar spine and help determine whether additional
imaging is needed.
1. X-rays – typically the first imaging study ordered. They provide important information
and sometimes cannot detect every early-stage pars stress fractures. Additional image
studies are then ordered. The X-rays include: standing AP and lateral –
flexion/extension
2. MRI (Magnetic Resonance Imaging) – often the preferred imaging study for adolescent
athletes because it does not use radiation. If early development of stress fracture, MRI
can detect bone stress reactions before a complete fracture develops and can also
evaluate the surrounding soft tissue such as disc, ligaments, nerves and muscles.
3. CT Scan (Computed Tomography) – provide detailed images of the vertebra, facet
joints, and pars interarticularis. Considered the best test for defining the size, location
and severity of a pars fracture. Especially helpful determining if the fracture is healing,
chronic or progressed to a nonunion.
4. SPECT (Single Emission Computed Tomography) – usually recommended when other image studies are inconclusive. This test is the most sensitive, differentiates between
acute and chronic fracture and helps assess fracture healing.
A pars fracture progresses through stages as repetitive stress exceeds the bone’s ability to
repair and heal. Early diagnosis is essential and offers the best chance for complete healing
without surgery.
Non-operative treatment for pars fracture, also called a pars defect or spondylolysis, often
depends on the athlete’s age, symptoms, stage of the fracture, healing potential and if there is
an associated vertebral slippage(spondylolisthesis). Many of the young athletes improve
without surgery, especially when the injury is diagnosed early.
Alleviate Pain, Activity Modification and Rest
To start there is no gold standard treatment. The first step is to reduce and alleviate pain and
inflammation with ice, heat and physician directed medications. Nonsteroidal anti-
inflammatory medications are often prescribed to reduce pain and swelling. They do not heal a
fracture but aid alleviating the pain. The next step is rest and modify athletic activities for at
least 6 weeks. Avoid the following motions:
Once pain is well controlled—typically after approximately 6 weeks of activity modification
and rest—a structured physical therapy program can begin. The primary goals are to restore
flexibility, improve core strength, correct movement abnormalities, and safely return the
athlete to sports while protecting the healing pars fracture.
A comprehensive rehabilitation program should focus on:
One commonly utilized rehabilitation protocol is the Watkins Back Program, which consists of
seven exercises progressing through five levels of difficulty. Athletes advance only when they
can complete each stage without pain.
Throughout rehabilitation, progression should be based on the athlete's symptoms and
functional recovery—not simply the number of weeks since the injury. A safe return to sports
requires pain-free spinal motion, restored core strength, normal flexibility, and the ability to
perform sport-specific activities without symptoms.
Returning to sports for the young athletes with back pain should be based on healing and
functional recovery not just passage of time. Even though most adolescent athletes can return
safely with nonoperative care, advancing too rapidly may delay healing and increase the risk of
a chronic pars defect. Athletes should meet or exceed specific clinical standards before
advancing to the next phase. Before returning to full participation the athletes should
demonstrate pain-free strength, functional performance and flexibility with clearance from
their sports spine surgeon.
Most pars fractures in young adolescents and young adults heal with activity modification,
bracing and physical therapy. However, surgery may be indicated and recommended when the
fracture does not heal and continues to cause mechanical low back pain that limits work, sports
and daily activities. Historically, patients were advised to undergo at least six months of
conservative treatment before considering surgery. In part because the surgical techniques
were invasive. Today, advanced imaging and new ultra-minimally invasive percutaneous and
endoscopic techniques allow few but select sports spine surgeons to better select ideal
candidates for surgical intervention.
Not every pars defect requires surgery. The best candidates are typically adolescents and young
adults with persistent symptoms and imaging findings that indicate the fracture has become a
chronic nonunion.
Surgery may be recommended if you have:
By Christopher A. Yeung, M.D.