Minimally invasive anterior lumbar interbody fusion followed by percutaneous pedicle screw fixation for isthmic spondylolisthesis.

BACKGROUND CONTEXT

Most surgeons have thought that posterior decompression is necessary to treat isthmic spondylolisthesis with leg pain. However, the surgical procedure not only requires wide muscle dissection but can also lead to spinal instability. The authors' treatment concept for isthmic spondylolisthesis is one-stage anterior reduction and posterior stabilization with minimally invasive surgical procedure without touching the spinal thecal sac and nerve.

PURPOSE

To investigate a new surgical concept of minimally invasive anterior-posterior fusion without posterior decompression for the treatment of isthmic spondylolisthesis with leg pain.

STUDY DESIGN

This is a retrospective study of 73 patients with isthmic spondylolisthesis who underwent minimally invasive anterior lumbar interbody fusion (mini-ALIF) followed by percutaneous pedicle screw fixation (PF) between October 2000 and February 2002.

PATIENT SAMPLE

A total of 73 patients with low-grade isthmic spondylolisthesis (46 with Grade 1 and 27 with Grade 2) who underwent mini-ALIF followed by percutaneous PF were retrospectively analyzed. There were 20 men and 53 women, with a mean age of 50.6 (range, 19 to 77) years. All patients had low back pain and referred or radicular leg pain or neurogenic intermittent claudication in walking or standing. Average duration of symptoms was 26 (range, 3 to 120) months.

OUTCOME MEASURES

The clinical outcome was graded according to the modified Macnab criteria.

METHODS

The authors retrospectively reviewed clinical and radiological data of 73 patients who had isthmic spondylolisthesis. All patients underwent mini-ALIF and percutaneous PF on the same day between October 2000 and February 2002. The mean follow-up period was 16 months (range, 12 to 26).

RESULTS

The mean operating time, blood loss and hospital stay were 210 minutes, 135 ml and 4.1 days, respectively. No blood transfusion was necessary. Clinical outcome was excellent in 26 patients (35.6%), good in 43 (58.9%), fair in 3 (4.1%) and poor in 1 (1.4%). The fusion rate was 97.3% (71 of 73). There were 6 cases (8.2%) of mini-ALIF complications and 6 (8.2%) of percutaneous PF complications. There were no postoperative neurologic deficits.

CONCLUSIONS

Mini-ALIF followed by percutaneous PF is an efficacious alternative for low-grade isthmic spondylolisthesis, and posterior decompression is not necessary to relieve leg symptoms. This minimally invasive combined procedure offers many advantages, such as preservation of posterior arch, no nerve retraction, less blood loss, excellent cosmetic results, high fusion rate and early discharge.