Background: Highly migrated intracanal disk herniation is not among the exclusion criteria of the interlaminar microendoscopic diskectomy (MED) procedure. The goal of this prospective, randomized, controlled study was to compare the effect of the size of the skin incision and the method of handling the multifidus muscle on the results of the interlaminar MED procedure versus conventional microdiskectomy in retrieving highly migrated intracanal disk herniations.
Methods: Seventy-three patients with highly migrated intracanal lumbar disk herniations treated with either minimal incision, multifidus-sparing MED or conventional microdiskectomy were observed for 2 years. Primary (clinical) outcomes data included the results of the Numerical Rating Scale (NRS) for back and leg pain and the Oswestry Disability Index (ODI) to quantify pain and disability, respectively. Secondary objective outcomes data included surgical time, blood loss, postoperative analgesics, length of hospital stay, time to return to work, the rates of revision surgery complications, and the results of the patient satisfaction index (PSI) and the modified MacNab criteria.
Results: At final follow-up, relief of leg pain was statistically significant for both groups. NRS back pain, ODI, PSI, and the modified MacNab criteria showed no improvement in the conventional microdiskectomy group. Secondary outcomes data in the MED group were significantly better than those for the control group.
Conclusions: Highly migrated intracanal lumbar disk herniations can be sufficiently retrieved using minimal incision, multifidus-sparing MED, which is an effective alternative to conventional microdiskectomy. The minimal skin incision and multifidus-sparing approach of the MED had a positive effect on clinical outcomes, which were stable throughout the 2-year follow-up period.
Level of Evidence: Therapeutic level II