Poor functional outcome following total knee replacement due to underlying lumbar canal stenosis: A case report

Why This Matters

Persistent leg pain and poor functional recovery after total knee replacement may not always originate from the knee or prosthesis. Lumbar spinal stenosis can produce overlapping lower-extremity symptoms, creating a diagnostic challenge when significant knee and spine pathology coexist.

This case highlights the importance of maintaining a broader differential diagnosis when postoperative symptoms are disproportionate to the apparent knee findings or fail to improve with rehabilitation. Recognizing a spinal source may substantially change evaluation, treatment planning, and the patient’s ability to participate in rehabilitation.

What the Research Found

This case report described a 59-year-old woman with bilateral lower-limb pain who underwent bilateral total knee replacement for radiographically severe osteoarthritis but continued to have disabling leg pain and poor functional improvement despite structured rehabilitation.

Subsequent spine evaluation identified neurogenic claudication with limited walking tolerance, and lumbar MRI demonstrated severe L4-L5 lumbar canal stenosis. Following lumbar decompression, her leg pain and neurogenic symptoms substantially improved, allowing better participation in knee rehabilitation.

KEY POINTS

  • Persistent symptoms after knee replacement were ultimately associated with lumbar spinal stenosis. Despite bilateral knee replacement and rehabilitation, the patient continued to experience disabling lower-extremity pain and poor functional recovery.
  • The clinical presentation included neurogenic claudication and limited walking tolerance. These findings prompted evaluation beyond the replaced knees.
  • Lumbar MRI demonstrated severe L4-L5 canal stenosis. The spinal abnormality provided an alternative explanation for the persistent lower-extremity symptoms.
  • Lumbar decompression substantially relieved the patient’s neurogenic symptoms. Improved leg symptoms subsequently allowed greater participation in knee rehabilitation.
  • Overlapping knee and lumbar symptoms complicated diagnosis. The authors emphasize evaluating lumbar pathology when symptoms are atypical, disproportionate, or persist despite apparently appropriate knee treatment.

Clinical Takeaways

    • Maintain a broad differential when recovery after knee replacement is unexpectedly poor. Persistent lower-extremity pain may reflect pathology outside the knee, including lumbar spinal stenosis.
    • Look for features suggesting a spinal source. Neurogenic claudication, restricted walking tolerance, and symptoms that do not correspond well with the knee or prosthesis should prompt consideration of lumbar evaluation.
    • Avoid assuming persistent postoperative pain represents prosthetic failure. In this case, prosthetic alignment was preserved while severe L4-L5 stenosis accounted for the ongoing neurogenic presentation.
    • Incorporate spine assessment when symptoms are atypical or disproportionate before knee replacement. The authors recommend considering coexisting lumbar pathology during preoperative planning in appropriate patients.
    • Recognize that unresolved neurologic symptoms may interfere with rehabilitation. Treating the identified lumbar stenosis in this patient improved neurogenic symptoms and enabled better participation in knee rehabilitation.

Where Collaborative Spine Care May Support This

Collaborative spine evaluation may be particularly useful when lower-extremity symptoms persist despite appropriate knee treatment or do not fit the expected postoperative course. Coordinated assessment among orthopedic, spine, rehabilitation, and other musculoskeletal clinicians may help distinguish knee-related limitations from neurogenic symptoms and identify when additional spine evaluation or escalation is appropriate.

Reference

Shafeeq GM, Faizan M, Bang P. Poor functional outcome following total knee replacement due to underlying lumbar canal stenosis: A case report. Cureus. 2026;18(3):e105668. doi:10.7759/cureus.105668.

VIEW FULL ABSTRACT

View full abstract: https://pubmed.ncbi.nlm.nih.gov/42028488/