- Lumbar Instability is typically defined as the loss of structural integrity between two adjacent vertebrae resulting in increased motion (hypermobility) at those segments.
- This increase in motion is usually greater than the normal anatomical limit of those segments.
- Lumbar instability is most often caused by Spondylolisthesis
- Severe lumbar spain or strain can also cause elements of lumbar instability. Other causes include repetitive strain and trauma.
- Differential Diagnosis
History, Signs & Symptoms
- Commonly a history of lower back pain, which may or may not be accompanied by sciatica (with or without neurological signs).
- Lumbar pain is often relived by rest or by waring a support, but may recur with a small amount of movement, such as a twist or sprain.
- Pain made worse by maintaining one posture for a long period of time (standing or sitting).
- Pain is usually relieved by mobilisation or manipulation, often with complete resolution of leg pain and neurological symptoms. However, relief is temporary, giving way to recurring pain a few days later with no obvious triggers.
- In some patients, a steadily increasing lumbosacral ache when extremes of spinal movement are sustained for more then 15 seconds
- Some patients may also report a painful arc with lumbar flexion or coming out of flexion.
- In some cases, lumbar instability may cause a ‘catch’ in the back or even a ‘locking’ sensation.
- Range of Movement: Patients may have trouble bending forward because of pain; flexion or returning from flexion may show visible asymmetry with a painful catch.
- General muscle hypertonicity to help stabilise unstable lumbar joints, multiple myofascial trigger points (MFTPs)
- Lumbar joint may be palpate for hypermobile or even “clunk” during Stork test or extension from a prone postion
- Orthopaedic Exam:
- Nerve tension tests may be positive in late stages
- Neurological deficits are usually absent, but may be present in the late stages
- Patient may experience pain in the first part of a sit-up arc, but no pain in the last part of the arc (Farfan compression test)
- In acute instability, patient may be unable to perform active bilateral leg raise
- In most cases x-ray imaging may show degenerative changes to the lumbar spine. However, only in severe lumbar instability would an x-ray demonstrate anterior shifting in affected vertebrae.
- In minor lumbar instability, osseous manipulation with focus on the hypomobile segments will help reduce symptoms.
- Rehabilitation exercises to stabilise hypermobile segments are an essential part of treatment
- Standard manual therapy protocol
- Ice and rest
- Massage therapy, hydrotherapy
- Conditioning & proprioceptive retraining
- Electrotherapy: TENS, IFC, Ultrasound
- Patient education – positions & activities to avoid
Severe Lumbar Instability
- With more severe grades of instability alternate treatment & caution should be employed
- Consider bracing to help stabilize lumbar spine
- Consider surgical consultation in severe cases or in the presence of neurocompressive radiculopathy
- Surgical treatment is usually spinal fusion