Surgical technique: Iliosacral reconstruction with minimal spinal instrumentation

Abstract

Background: Posterior pelvic ring reconstruction can be challenging and controversial. The choice regarding whether to reconstruct and how to reconstitute the pelvic ring is unclear. Many methods provide stability but often are technically difficult and require excessive dissection. DESCRIPTION OF SURGICAL TECHNIQUE: This unique reconstructive technique uses the anterior aspect of the iliac crest with its attached muscle pedicle to provide a biologic scaffold for healing. The construct is secured with pedicle screws into the posterior column and S1 vertebral body with a spinal rod locked in compression. No additional fixation is used proximally into the lumbar spine. The iliac crest remains attached to the gluteus medius, allowing potential abductor function.

Methods: We retrospectively reviewed six patients who underwent iliosacral resection with this reconstruction. The mean age of the patients was 41 years. Complications were recorded. One patient died 6 months postoperatively. Musculoskeletal Tumor Society 1993 (MSTS '93) score and Toronto Extremity Salvage Score (TESS) were obtained at a minimum 1-year followup in five patients. Healing was assessed radiographically. The minimum followup was 6 months (median, 33 months; range, 6-53 months).

Results: The mean MSTS '93 score was 72% and mean TESS was 66. All posterior column graft sites healed. At last followup, four of the five surviving patients had a stable pseudarthrosis at the proximal sacral site. One patient had a local recurrence and experienced failure of instrumentation without collapse or rotation of the hemipelvis 3 years postoperatively.

Conclusions: This technique provides a simple way to reconstruct the pelvic ring after iliosacral resection with clinical outcomes comparable to those for other methods. The method is a potential alternative for reconstruction of the posterior pelvic ring after resecting the ilium although reliable healing of the sacral site needs to be improved.

Fig. 1

The planned resection of a tumor in the posterior left ilium is shown in this drawing. The uninvolved anterior iliac crest graft is harvested as part of the exposure with a portion of the gluteus medius attached.

Fig. 2

The pelvis and anterior iliac crest pedicle graft after tumor resection is shown.

Fig. 3

The graft inserted as a strut between the acetabulum and sacrum with the instrumentation in place can be seen in this illustration of the lateral side.

Fig. 4A–D

(A) An AP radiograph of the pelvis of a 17-year-old girl with a fibrosarcoma of the posterior left ilium is shown. Her (B) T1 and (C) T2 axial MR images show a localized mass sparing the acetabulum and anterosuperior iliac spine. (D) Four years after reconstruction, the patient occasionally takes NSAIDs for pain. She had an asymptomatic, stable pseudarthrosis at the sacral site. Her MSTS ’93 score was 93% and TESS was 87.5. She has no restriction of function and can walk for unlimited distances with nearly normal gait and good abductor function.

Fig. 5A–B

(A) AP and (B) lateral radiographs of the pelvis of a 31-year-old woman obtained at her 4-year followup show the reconstruction after Types I/IV resection. There is healing of the acetabular and sacral sites.

Fig. 6A–C

(A) An AP radiograph of the pelvis of a 58-year-old man and (B) a T1-weighted MRI axial cut are shown. The patient had a diagnosis of chondrosarcoma of the right ilium. He underwent a primary excision and reconstruction. (C) At 34 months, he had slight pain with a loose sacral screw and stable pseudarthrosis. He walks with a cane, and his MSTS ’93 score was 76 and TESS was 53.