What is the prognosis of a patient after multilevel lumbar (lower back) microdiscectomy with no residual symptoms, except for a diminished knee jerk reflex, and who is otherwise functioning well?

From the Guidelines

The prognosis for a patient who has undergone multilevel lumbar microdiscectomy and is currently functioning well with only diminished knee jerk reflex is generally favorable. Most patients who reach this stage of recovery without significant residual symptoms can expect to maintain their improved functional status long-term. The diminished knee jerk reflex (patellar reflex) likely indicates some residual nerve root involvement, typically affecting the L3-L4 nerve roots, but this isolated finding without accompanying pain or weakness is not usually functionally limiting.

Some key points to consider in the management and prognosis of such patients include:

• Physical therapy focusing on core strengthening and proper body mechanics should be continued for at least 6-12 months post-surgery to optimize outcomes and prevent recurrence 1.
• The patient should avoid heavy lifting (>20 pounds) for at least 3 months and gradually return to normal activities as tolerated.
• Regular follow-up appointments at 3,6, and 12 months post-surgery are recommended to monitor for any changes in neurological status.
• The isolated reflex abnormality without other symptoms suggests that while there may be some permanent nerve damage affecting the reflex arc, the functional nerve pathways responsible for strength, sensation, and pain transmission have adequately recovered.
• This pattern is consistent with successful decompression of the affected nerve roots with some residual subclinical neuropathy that does not impact daily function.

It's also important to note that the natural history of lumbar disc herniation with radiculopathy in most patients is for improvement within the first 4 weeks with noninvasive management 1. However, for patients with persistent radicular symptoms despite noninvasive therapy, discectomy or epidural steroids are potential treatment options 1.

In terms of diagnostic approaches, magnetic resonance imaging (MRI) or CT is recommended for evaluating patients with persistent back and leg pain who are potential candidates for invasive interventions 1. Clinicians should be aware that findings on MRI or CT are often nonspecific, and decisions should be based on the clinical correlation between symptoms and radiographic findings, severity of symptoms, patient preferences, surgical risks, and costs 1.

Overall, the prognosis for a patient who has undergone multilevel lumbar microdiscectomy and is currently functioning well with only diminished knee jerk reflex is generally favorable, with most patients able to maintain their improved functional status long-term with appropriate management and follow-up.

From the Research

Prognosis After Multilevel Lumbar Microdiscectomy

The prognosis of a patient after multilevel lumbar microdiscectomy with no residual symptoms, except for a diminished knee jerk reflex, and who is otherwise functioning well can be considered favorable based on existing studies.

• Studies have shown that patients who undergo multilevel minimally invasive lumbar decompression and/or microdiscectomy experience significant improvements in functional outcomes and pain scores 2.
• A study comparing clinical outcomes in patients undergoing one- and two-level minimally invasive lumbar microdiscectomy found that patients who underwent two-level discectomy had similar improvements in patient-reported outcome measures (PROMs) compared to those who underwent one-level discectomy, although patients who underwent one-level discectomy had greater improvement in leg pain 3.
• Another study on patient-reported outcome measures after multilevel lumbar total disc arthroplasty for the treatment of multilevel degenerative disc disease found that patients experienced significant and sustained improvements in pain and disability scores, with 92% of patients reporting good or excellent satisfaction with treatment at final review 4.
• A prognostic model for failure and worsening after lumbar microdiscectomy developed using data from the Norwegian Registry for Spine Surgery found that the model could be useful in assisting physicians and patients in the clinical decision-making process prior to surgery, although the study did not specifically address the prognosis of patients with a diminished knee jerk reflex 5.
• The presence of a diminished knee jerk reflex may be a residual effect of the surgery or the underlying condition, but it is not necessarily indicative of a poor prognosis, as patients can still experience significant improvements in functional outcomes and pain scores despite residual neurological deficits 6, 2.