Failure within one year following subtotal lumbar discectomy.

BACKGROUND: Reherniation within the first year following subtotal lumbar discectomy is a rare but noteworthy event. We performed a retrospective, case-controlled study to evaluate the clinical outcomes after early recurrent lumbar disc reherniation.

METHODS: The records of 1320 patients who had undergone primary subtotal lumbar discectomy were analyzed retrospectively by an independent reviewer. Patients with documented reherniation within twelve months were evaluated with regard to the location of the reherniation, the neurologic status, the rate of reoperation, and the subjective outcome. Patients were evaluated on the basis of a physical examination and a review of medical records. Disc morphology, anular competence, and the presence of free fragments were categorized with use of a modified five-part Carragee classification system. The mean duration of follow-up for this group was 52.6 months. Clinical outcomes were assessed with use of the Oswestry score and the modified criteria of McNab. Twenty-nine historical control patients who had undergone uncomplicated subtotal lumbar discectomy were selected.

RESULTS: We identified fourteen recurrent lumbar disc herniations within one year after the index procedure. All fourteen patients had radicular pain and weakness prior to, and complete relief of radiculopathy after, the index procedure. All reherniations occurred at the same level as the index procedure, but eight occurred in a different direction than the original herniation. All patients underwent reexploration and discectomy, and two underwent single-level posterolateral arthrodesis. Two patients underwent a third procedure. The average Oswestry score at the time of the latest follow-up was 6.4 for the recurrent herniation group, compared with 6.9 for the controls. The outcomes according to the modified McNab criteria were not significantly different between the groups, with the numbers available. The mean duration of follow-up after the second discectomy was 52.6 months.

CONCLUSIONS: The rate of early reherniation after subtotal lumbar discectomy is low (1%). It is important to consider the possibility of iatrogenic instability during surgery on the lumbar spine for the treatment of reherniation. Patients who undergo reoperation because of early recurrent lumbar disc herniation can have clinical outcomes comparable with those of patients undergoing an uncomplicated subtotal lumbar discectomy.