Migration of Rod into Retroperitoneal Region: A Case Report and Review of the Literature

Abstract

Spinal stabilization with fusion is the widely used method for traumatic or pathologic fracture of spine, spinal stenosis, and spondylolisthesis. Complications may emerge during or after the operations. Infection, hematoma and neurological deficits are early noticed findings. Screw and/or rod fractures present in long-term after surgery. Rod migration in out of the spinal column is a rare entity. A 67-year-old woman was visited our clinic for right leg pain. She had a previous spinal instrumentation surgery for spondylolisthesis in another center 6 years before. After radiological work-up, a distally migrated rod piece was observed in the retroperitoneal portion. The patient was operated for degenerative change; old instruments were replaced and extended to the L2 level with posterior spinal fusion. After the operation, her right leg pain improved. The asymptomatic migrated rod piece has regularly been followed clinically and radiologically, since then. Although it has rarely been reported, migration of the instrumentation material should be kept in mind. Spinal fixation without fusion makes the mechanical system vulnerable to motion effects of spine, especially in a degenerative and osteoporotic background. Long-term, even life-long follow-up is necessary for late term complications.

Distal Migration of the Rods of a Constrained Polyaxial Pedicle Screw System

“…In addition, there were no signs of eccentric coupling between the nut and screw head intra-operatively at the index surgeries or at the times of revision. Although it has been reported that these rods can get loose and migrate leaving behind a tight and properly placed pedicle screw caps without evidence of loosening (7) , in our cases, the screw caps were loose and backed-off by one or two turns. It is unclear why the caps got loose although after experience with the first case, additional time was spent ensuring that the torque applied to the caps was of sufficient amount as prescribed by the manufacturer.…”

“…Leute et al (9) reported a case of set screw fracture with cage dislocation after an open TLIF procedure, they acknowledged this as malpositioning of set screws or flaws in their production. In another case by Bayri et al (7) , a patient, who had underwent spinal instrumentation surgery for spondylolisthesis 6 years ago, was detected to have migration of rod into retroperitoneal region, the reason for movement of the rod in this case was due to unbalanced motion at the instrumented level without any fusion. This type of implant failure may be secondary to several reasons: technique related, implant design defects, patient related factors and material failure with or without a non-rigid fixation (pseudoarthrosis).…”

“…Such a complication associated with very similar patients and a single instrumentation system has not been reported previously. The case reports of spine rod migrations are mainly of either Harrington rods or of Luque rod instrumentation system, both unconstrained systems in regard to the anchor-rod interface (7) . In all these cases described, there was a significant time lapse between the index surgery and discovery of a migrated rod.…”

Migration and Spontaneous Extrusion of a Lumbar Spinal Fusion Rod From the Gluteal Region

“…However, the exact soft tissue track of the migrated rod is not known and the patient was fortunate to not have developed skin or soft tissue complications such as a chronic or infected sinus tract formation. In a literature review of rod migration by Bayri et al [ 8 ], all cases necessitated surgical intervention for rod removal, apart from those cases where the patients declined surgery. Our case is unique and the first in the literature to have extruded from the soft tissue spontaneously, without the need for surgical removal.…”

Bilateral rod loosening and sequential distal migration after thoracolumbar junction fracture stabilisation.

“…Distal rod migration remains uncommon and has been reported in a variety of anatomical locations, including the retroperitoneal region, the knee, and the pelvis. 1,2,3 It is postulated that spinal fixation without fusion might allow the mechanical system some vulnerability to motion effects of the spine. Bilateral distal rod migration is rarer still.…”