Degenerative Disc Disease (Lumbar Spondylosis): Pathology, Physiotherapy Evaluation, and Rehabilitation Program

Introduction

Degenerative Disc Disease (DDD), often associated with lumbar spondylosis, is a common condition characterized by the progressive degeneration of the intervertebral discs and associated structures in the lumbar spine. It is a major cause of chronic low back pain, affecting 60–85% of adults at some point in their lives, with symptoms ranging from mild and transient to chronic and debilitating. This article explores the pathology of DDD, outlines physiotherapy evaluation techniques, and details a structured rehabilitation program, drawing on evidence from PubMed where relevant.

Pathology of Degenerative Disc Disease (Lumbar Spondylosis)

Lumbar spondylosis encompasses degenerative changes in the intervertebral discs, vertebral bodies, and facet joints, often resulting from aging, mechanical stress, or genetic predisposition. The intervertebral discs, composed of a soft nucleus pulposus and a fibrous annulus fibrosus, provide support, flexibility, and load-sharing in the spine. Degenerative changes disrupt this architecture, leading to pain and functional impairment.

Pathological Changes

  1. Disc Degeneration: The process begins with disc desiccation (loss of water content), reducing disc height and elasticity. The annulus fibrosus may develop tears, which can progress to radial tears, increasing the risk of disc protrusion or herniation. These changes impair the disc’s ability to absorb mechanical stress, contributing to pain.
  2. Facet Joint Degeneration: Degeneration of the zygapophyseal (facet) joints, termed facet syndrome, occurs alongside disc changes. This can lead to subluxation, instability, or the formation of facet cysts, further contributing to pain or neural compression.
  3. Endplate and Vertebral Changes: Sclerosis of the vertebral endplates and formation of osteophytes (bone spurs) at the vertebral apophyses are common. These changes can narrow the spinal canal or neural foramina, potentially causing spinal stenosis or radiculopathy.
  4. Phases of Degeneration:
    • Phase I (Dysfunction Phase): Early annular tears and disc desiccation begin, often asymptomatic but detectable on imaging.
    • Phase II (Instability Phase): Progressive disc resorption, annular tears, and facet degeneration lead to mechanical instability, increasing pain and dysfunction.
    • Phase III (Stabilization Phase): Fibrosis, continued disc narrowing, and osteophyte formation stabilize the spine but may cause stiffness and persistent pain.
  5. Genetic and Environmental Factors: Twin studies suggest that 47–66% of disc degeneration variability is due to genetic factors, with environmental factors like physical loading contributing only 2–10%. Polymorphisms in inflammatory pathways and Vitamin D receptor alleles are linked to progression.

Clinical Presentation

Patients with lumbar spondylosis present with a range of symptoms, including:

Physiotherapy Evaluation

A thorough physiotherapy evaluation is critical to assess the extent of impairment, identify pain generators, and guide treatment. The evaluation includes subjective and objective assessments, tailored to the patient’s presentation.

Subjective Assessment

Objective Assessment

  1. Postural Analysis: Observe for abnormal spinal alignment, such as loss of lumbar lordosis or scoliosis, which may indicate compensatory mechanisms.
  2. Range of Motion (ROM): Measure lumbar flexion, extension, lateral flexion, and rotation using a goniometer or inclinometer. Restrictions may indicate stiffness or instability.
  3. Neurological Examination: Test reflexes, sensation, and muscle strength to identify nerve root involvement. For example, L4-L5 or L5-S1 disc herniations may affect the L4, L5, or S1 nerve roots, causing specific sensory or motor deficits.
  4. Special Tests: Perform tests like the Straight Leg Raise (SLR) for radiculopathy or the Stork Test for spondylolisthesis to assess stability and neural tension.
  5. Palpation and Manual Testing: Assess for tenderness, muscle spasm, or joint dysfunction in the lumbar spine and surrounding musculature.
  6. Functional Testing: Evaluate movement patterns during activities like sitting, standing, or walking to identify compensatory strategies or weaknesses.

Imaging and Correlation

While imaging (X-rays, MRI, CT) is not always necessary, it can confirm degenerative changes like disc space narrowing, osteophytes, or stenosis. MRI is preferred for assessing soft tissue and disc pathology, using classifications like Pfirrmann (for disc morphology) or Modic (for endplate changes). However, imaging findings should be correlated with clinical symptoms, as asymptomatic individuals often show similar changes.

Rehabilitation Program

Conservative management, including physiotherapy, is the cornerstone of treatment for lumbar spondylosis, particularly in the absence of severe neurological deficits. A multimodal rehabilitation program aims to reduce pain, improve mobility, restore function, and prevent progression. The following program is evidence-based, drawing on PubMed literature where applicable.

Phase 1: Pain Management and Protection (0–6 Weeks)

Goals: Reduce pain and inflammation, protect the spine, and educate the patient.

Phase 2: Mobility and Strengthening (6–12 Weeks)

Goals: Restore ROM, improve muscle strength, and enhance spinal stability.

Phase 3: Functional Restoration and Maintenance (12+ Weeks)

Goals: Enhance functional capacity, prevent recurrence, and promote long-term spine health.

Special Considerations

Conclusion

Degenerative Disc Disease (lumbar spondylosis) is a multifactorial condition with significant impacts on quality of life. Its pathology involves progressive degeneration of the discs, facet joints, and vertebral structures, influenced by genetic and mechanical factors. Physiotherapy evaluation provides a comprehensive assessment of pain, function, and neurological status, guiding conservative management. A structured rehabilitation program, emphasizing pain relief, mobility, strengthening, and functional restoration, is effective for most patients, supported by evidence from PubMed. While surgical options exist, nonoperative care remains the first line, with physiotherapy playing a central role in improving outcomes and preventing progression.