The patient came to the clinic 23-April with agonizing bilateral sciatica and severe weak both feet with inability to walk more than 100 meters.

The patient was operated elsewhere 22-May-2006 for PLD L4-5 with subsequent deterioration of her condition.

MRI done 26-January-2007 with LSS X-ray confirmed the presence of III degree spondylolisthesis L4-5 with complete absence of the isthmi.

On examination: the patient had exaggerated scoliotic stance with SLRS 40 degrees both sides with more pain in the right. The right foot dorsi and planterflexion were 3/5 and the left 4/5. There was hypalgesia of the right L5 and S1 territories.

Skeletonization of the lateral masses of L5-S1 both sides and the L4-5 respectively. There were no lateral masses. The transverse processii were identified and using transpedicular screws 45 mm length and 7.5 mm width with 2 polyaxial type in the upper side and monoaxial in the lower part, transpedicular screw fixation was performed with distraction-reduction with bridge inserted between the 2 rods.

Smooth postoperative recovery with normalization of the power of both feet.

The patient underwent surgery for discectomy 1 year ago elsewhere. The isthmi were destroyed with subsequent progression of III degree spondylolisthesis. It is hard to tell if that was the result of surgery, or a hidden finding, which was escaped during surgery. It happens, as in this example, that the patient got fracture of the isthmi before surgery, but removing the isthmi during the first surgery still possible.

In either cases, considering, that the patient had deterioration, without improvement during the 12 months period, surgery with fusion is the only solution to this situation.