A retrospective study of iliac crest bone grafting techniques with allograft reconstruction: do patients even know which iliac crest was harvested? Clinical article.

OBJECT: Considerable biological research has been performed to aid bone healing in conjunction with lumbar fusion surgery. Iliac crest autograft is often considered the gold standard because it has the vital properties of being osteoconductive, osteoinductive, and osteogenic. However, graft site pain has been widely reported as the most common donor site morbidity. Autograft site pain has led many companies to develop an abundance of bone graft extenders, which have limited proof of efficacy. During the surgical consent process, many patients ask surgeons to avoid harvesting autograft because of the reported pain complications. The authors sought to study postoperative graft site pain by simply asking patients whether they knew which iliac crest was grafted when a single skin incision was made for the fusion operation. METHODS: Twenty-five patients underwent iliac crest autografting with allograft reconstruction during instrumented lumbar fusion surgery. In all patients the autograft was harvested through the same skin incision but with a separate fascial incision. At various points postoperatively, the patients were asked if they could tell which iliac crest had been harvested, and if so, how much pain did it cause (10-point Numeric Rating Scale). RESULTS: Most patients (64%) could not correctly determine which iliac crest had been harvested. Of the 9 patients who correctly identified the side of the autograft, 7 were only able to guess. The 2 patients who confidently identified the side of grafting had no pain at rest and mild pain with activity. One patient who incorrectly guessed the side of autografting did have significant sacroiliac joint degenerative pain bilaterally. CONCLUSIONS: Results of this study indicate the inability of patients to clearly define their graft site after iliac crest autograft harvest with allograft reconstruction of the bony defect unless they have a separate skin incision. This simple, easily reproducible pilot study can be expanded into a larger, multiinstitutional investigation to provide more definitive answers regarding the ideal, safe, and cost-effective bone graft material to be used in spinal fusions.

Compression fracture in the middle of a chronic instrumented fusion that developed into pseudarthrosis after balloon kyphoplasty.

There are only 2 documented cases of vertebral compression fractures occurring within a solid lumbar fusion mass: one within the fusion mass after hardware removal and the other within the levels of the existing instrumentation 1 year postoperatively. The authors report a case of fracture occurring in a chronic (> 30 years) solid instrumented fusion mass in a patient who underwent kyphoplasty. The pain did not improve after the kyphoplasty procedure, and the patient developed a posterior cleft in the fusion mass postoperatively. The patient, a 46-year-old woman, had undergone a T4-L4 instrumented fusion with placement of a Harrington rod when she was 12 years old. Adjacent-segment breakdown developed, and her fusion was extended to the pelvis, with pedicle screws placed up to L-3 to capture the existing fusion mass. Almost 2 years after fusion extension, she fell down the stairs and suffered an L-2 compression fracture, which is when kyphoplasty was performed without pain relief, and she then developed a cleft in the posterior fusion mass that was previously intact. She refused further surgical options. This case report is meant to alert surgeons of this possibility and allow them to consider the rare occurrence of fracture within the fusion mass when planning extension of chronic spinal fusions.

Operating room radiation exposure in cone beam computed tomography-based, image-guided spinal surgery: clinical article.

OBJECT: Surgeon and operating room (OR) staff radiation exposure during spinal surgery is a concern, especially with the increasing use of multiplanar fluoroscopy in minimally invasive spinal surgery procedures. Cone beam computed tomography (cbCT)-based, 3D image guidance does not involve the use of active fluoroscopy during instrumentation placement and therefore decreases radiation exposure for the surgeon and OR staff during spinal fusion procedures. However, the radiation scatter of a cbCT device can be similar to that of a standard 64-slice CT scanner and thus could expose the surgeon and OR staff to radiation during image acquisition. The purpose of the present study was to measure radiation exposure at several unshielded locations in the OR when using cbCT in conjunction with 3D image-guided spinal surgery in 25 spinal surgery cases. METHODS: Five unshielded badge dosimeters were placed at set locations in the OR during 25 spinal surgery cases in which cbCT-based, 3D image guidance was used. The cbCT device (O-ARM) was used in conjunction with the Stealth S7 image-guided platform. The radiology department analyzed the badge dosimeters after completion of the last case. RESULTS: Fifty high-definition O-ARM spins were performed in 25 patients for spinal registration and to check instrumentation placement. Image-guided placement of 124 screws from C-2 to the ileum was accomplished without complication. Badge dosimetry analysis revealed minimal radiation exposure for the badges 6 feet from the gantry in the area of the anesthesiology equipment, as well as for the badges located 10-13 feet from the gantry on each side of the room (mean 0.7-3.6 mrem/spin). The greatest radiation exposure occurred on the badge attached to the OR table within the gantry (mean 176.9 mrem/spin), as well as on the control panel adjacent to the gantry (mean 128.0 mrem/spin). CONCLUSIONS: Radiation scatter from the O-ARM was minimal at various distances outside of and not adjacent to the gantry. Although the average radiation exposure at these locations was low, an earlier study, undertaken in a similar fashion, revealed no radiation exposure when the surgeon stood behind a lead shield. This simple precaution can eliminate the small amount of radiation exposure to OR staff in cases in which the O-ARM is used.