Computer-assisted anterior spinal surgery for a case of recurrent giant cell tumor

Management of spinal giant cell tumors

BACKGROUND CONTEXT

Spinal giant cell tumors (SGCT) remain challenging tumors to treat. Although advancements in surgical techniques and adjuvant therapies have provided new options for treatment, evidence-based algorithms are lacking.

PURPOSE

This study aims to review the peer-reviewed literature that addresses current treatment options and management of SGCT, to produce an evidence-based treatment algorithm.

STUDY DESIGN/SETTING

A systematic review was performed.

METHODS

Articles published between January 1, 1970 and March 31, 2015 were selected from PubMed and EMBASE searches using keywords "giant cell tumor" AND "spine" AND "treatment." Relevant articles were selected by the authors and reviewed.

RESULTS

A total of 515 studies were identified, of which 81 studies were included. Complete surgical resections of SCGT resulted in the lowest recurrence rates. However, morbidity of en bloc resections is high and in some cases, surgery is not possible. Intralesional resection can be coupled with adjuvant therapies, but evidence-based algorithms for use of adjuvants remain elusive. Several recent advancements in adjuvant therapy may hold promise for decreasing SGCT recurrence, specifically stereotactic radiotherapy, selective arterial embolization, and medical therapy using denosumab and interferon.

CONCLUSIONS

Complete surgical resection of SGCT should be the goal when possible, particularly if neurologic impairment is present. Denosumab holds promise as an adjuvant and perhaps stand-alone therapy for SGCT. Spinal giant cell tumors should be approached as a case-by-case problem, as each presents unique challenges. Collaboration of spine surgeons, radiation oncologists, and medical oncologists is the best practice for treating these difficult tumors.

Robotic assisted surgeries for the treatment of spine tumors

Background

Surgery plays an important role in the treatment of patients with metastatic or primary spine tumors. In recent years, various new techniques, such as robotic assisted spine surgery have been developed which has shown some promising results by improving the accuracy of spinal instrumentation and reducing potential complications. The purpose of this study was to evaluate our early experience using robotic guidance in the treatment of spinal tumors.

Methods

Data were collected from medical records for each surgery in which the robotic system was used to assist with biopsy, pedicle screw placement and/or vertebral augmentation in the treatment of spinal tumors. Patient's age, gender, diagnosis and surgical procedure were documented. The surgical time, estimated blood loss, peri-operative and post-operative complications were obtained. The visual analog scale (VAS) for back pain and leg pain were also recorded.

Results

A total of 9 consecutive patients (7 female, 2 male) were included in this study, beginning with the first case experience. The mean age of the patients was 60 years (range 47-69). All patients presented with thoracic or lumbar vertebral collapse and/or myelopathy. Robotic assisted posterior instrumentation was successfully performed in all patients. Robotic assisted vertebral augmentation was performed in 4 patients. The average number of levels instrumented was 5. The average surgery time (skin to skin) was 4 hours and 24 minutes and the mean blood loss was 319 ml. There were no complications perioperatively or through the latest follow-up. Seven of the 9 patients reported improved back pain and/or leg pain at the latest follow-up and the data were not available in two patients.

Conclusions

The published complication rates of spinal tumor surgeries range between 5.3% and 19%. With robotic assistance, the surgical complication rate appears improved over the historical figures. Our study shows that the robotic system was safe and performed as desired in the treatment of metastatic and primary spine tumors. These results support that further evaluation in a larger series of patients.

What is the learning curve for robotic-assisted pedicle screw placement in spine surgery?

BACKGROUND

Some early studies with robotic-assisted pedicle screw implantation have suggested these systems increase accuracy of screw placement. However, the relationship between the success rate of screw placement and the learning curve of this new technique has not been evaluated.

QUESTIONS/PURPOSES

We determined whether, as a function of surgeon experience, (1) the success rate of robotic-assisted pedicle screw placement improved, (2) the frequency of conversion from robotic to manual screw placement decreased, and (3) the frequency of malpositioned screws decreased.

METHODS

Between June 2010 and August 2012, the senior surgeon (IHL) performed 174 posterior spinal procedures using pedicle screws, 162 of which were attempted with robotic assistance. The use of the robotic system was aborted in 12 of the 162 procedures due to technical issues (registration failure, software crash, etc). The robotic system was successfully used in the remaining 150 procedures. These were the first procedures performed with the robot by the senior surgeon, and in this study, we divided the early learning curve into five groups: Group 1 (Patients 1-30), Group 2 (Patients 31-60), Group 3 (Patients 61-90), Group 4 (Patients 91-120), and Group 5 (Patients 121-150). One hundred twelve patients (75%) had spinal deformity and 80 patients (53%) had previous spine surgery. The accuracy of screw placement in the groups was assessed based on intraoperative biplanar fluoroscopy and postoperative radiographs. The results from these five groups were compared to determine the effect on the learning curve. The numbers of attempted pedicle screw placements were 359, 312, 349, 359, and 320 in Groups 1 to 5, respectively.

RESULTS

The rates of successfully placed screws using robotic guidance were 82%, 93%, 91%, 95%, and 93% in Groups 1 to 5. The rates of screws converted to manual placement were 17%, 7%, 8%, 4%, and 7%. Of the robotically placed screws, the screw malposition rates were 0.8%, 0.3%, 1.4%, 0.8%, and 0%.

CONCLUSIONS

The rate of successfully placed pedicle screws improved with increasing experience. The rate of the screws that were converted to manual placement decreased with increasing experience. The frequency of screw malposition was similar over the learning curve at 0% to 1.4%. Future studies will need to determine whether this finding is generalizable to others.

LEVEL OF EVIDENCE

Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Multiplanar osteotomies guided by navigation in chondrosarcoma of the knee

Surgical resection with adequate margins is the treatment of choice in chondrosarcoma. However, well-circumscribed lesions can be completely resected by performing multi-planar osteotomies guided by computer-assisted navigation. This type of resection had been recently described in select patients with sarcomas; however, these osteotomies are technically demanding to plan and perform intraoperatively. The use of navigation to assist in surgery is becoming more frequently described in orthopedic oncology.The authors performed multiplanar osteotomy resections guided by navigation and reconstruction with intercalary allografts in 5 patients with chondrosarcoma around the knee. All the patients were women, with a mean age of 56 years. Four tumors were located in the distal femur and 1 in the proximal tibia. The 5 surgical anatomic specimens were 3-dimensionally reconstructed postoperatively and superimposed on a preoperative plan to check whether the resected specimen was consistent with the preoperative planned resection. At final follow-up, no patient experienced a local recurrence or metastasis. Four osteotomies each were performed in 3 patients, and 3 osteotomies each were performed in 2 patients, so 18 planes were evaluated. Mean difference in distance between preoperative vs final planes was 2.43 mm. Average functional score was 29 points. All patients resumed activities of daily living without restriction. This study's results show that navigation with adequate preoperative planning allows surgeons to intraoperatively reproduce the planned resection with accuracy in complex multiplanary resections.

Robotic-assisted pedicle screw placement: lessons learned from the first 102 patients

INTRODUCTION

Surgeons' interest in image and/or robotic guidance for spinal implant placement is increasing. This technology is continually improving and may be particularly useful in patients with challenging anatomy. Only through careful clinical evaluation can its successful applications, limitations, and areas for improvement be defined. This study evaluates the outcomes of robotic-assisted screw placement in a consecutive series of 102 patients.

METHODS

Data were recorded from technical notes and operative records created immediately following each surgery case, in which the robotic system was used to guide pedicle screw placement. All cases were performed at the same hospital by a single surgeon. The majority of patients had spinal deformity and/or previous spine surgery. Each planned screw placement was classified as: (1) successful/accurately placed screw using robotic guidance; (2) screw malpositioned using robot; (3) use of robot aborted and screw placed manually; (4) planned screw not placed as screw deemed non essential for construct stability. Data from each case were reviewed by two independent researchers to indentify the diagnosis, number of attempted robotic guided screw placements and the outcome of the attempted placement as well as complications or reasons for non-placement.

RESULTS

Robotic-guided screw placement was successfully used in 95 out of 102 patients. In those 95 patients, 949 screws (87.5 % of 1,085 planned screws) were successfully implanted. Eleven screws (1.0 %) placed using the robotic system were misplaced (all presumably due to "skiving" of the drill bit or trocar off the side of the facet). Robotic guidance was aborted and 110 screws (10.1 %) were manually placed, generally due to poor registration and/or technical trajectory issues. Fifteen screws (1.4 %) were not placed after intraoperative determination that the screw was not essential for construct stability. The robot was not used as planned in seven patients, one due to severe deformity, one due to very high body mass index, one due to extremely poor bone quality, one due to registration difficulty caused by previously placed loosened hardware, one due to difficulty with platform mounting and two due to device technical issues.

CONCLUSION

Of the 960 screws that were implanted using the robot, 949 (98.9 %) were successfully and accurately implanted and 11 (1.1 %) were malpositioned, despite the fact that the majority of patients had significant spinal deformities and/or previous spine surgeries. "Tool skiving" was thought to be the inciting issue with the misplaced screws. Intraoperative anteroposterior and oblique fluoroscopic imaging for registration is critical and was the limiting issue in four of the seven aborted cases.

Navigation-assisted surgery for bone and soft tissue tumors with bony extension

BACKGROUND

The navigation system was introduced to orthopaedic surgery in the 1990s. More recently, CT-based navigation systems have been used more commonly in spine and joint replacement surgery because of their precision.

QUESTIONS/PURPOSES

The aim of our study was to evaluate the accuracy and efficacy of navigation-assisted excision of bone and soft tissue tumors.

METHODS

From 2006 to 2009, we performed navigation-assisted surgery in 16 patients, 11 males and five females, with a mean age of 39 years (range, 13-70 years). We diagnosed nine benign bone tumors and seven malignant bone and soft tissue tumors. In two patients, the malignant soft tissue tumors infiltrated the adjacent bones. Nine excisional biopsies for benign tumors and seven en bloc excisions for malignant tumors were performed. In all cases, the point registration method was performed using 10 skin markers, which were placed around the tumor. Each excisional difference between the preoperative and postoperative plans was evaluated histologically or by postoperative CT.

RESULTS

The mean accuracy of this system, which was determined using skin markers, was 0.93 mm (range, 0.6-1.2 mm). All biopsy and excision samples were evaluated by pathologic examination and postoperative CT imaging. The mean difference between the planned margin and postoperative CT or excised histologic specimen was 0 mm to 4 mm. The mean followup was 34 months (range, 10-54 months). There were no local recurrences, except for excision of skip metastases in a patient with a chordoma.

CONCLUSION

We report our experience with navigation-assisted surgery for bone and soft tissue tumors. Navigation-assisted surgery could be indicated for sufficiently reliable, accurate, and minimally invasive resections.

Cervicothoracic giant cell tumor expanding into the superior mediastinum: total excision by combined anterior-posterior approach

This article describes a case of cervicothoracic giant cell tumor expanding into the superior mediastinum treated by total spondylectomy. A 42-year-old-man presented with back pain and paraparesis. Magnetic resonance imaging revealed the collapse of the T2 vertebral body. The spinal cord was severely compressed by the tumor mass. The tumor had spread from T2 to the mediastinum, so that the tumor was in contact with many vital structures. To resect the tumor completely, total spondylectomy from T1 to T3 was performed through a combined anterior-posterior approach. The tumor was dissected from the vital structures using an anterior low cervical approach and splitting one-third of the sternum. En bloc vertebral resection from Th1 to Th3, including the tumor pseudocapsule, was possible through a posterior approach. The tumor around the nerve roots or dura was resected piece by piece since it was possible to separate the capsulated tumor from the dura. Splitting one-third of the sternum allowed separation of the tumor from the anterior vital structures, under direct vision. This allowed en bloc vertebral resection of the tumor that had spread to the mediastinum from T2 and in the craniocaudal direction from T1 to T3. Although giant cell tumor is benign, it can be locally aggressive. Complete excision of a giant cell tumor is the best treatment option even for the cervicothoracic spine, to protect the vital structures or neural function.

Extensive total spondylectomy for recurrent giant cell tumor in the thoracic spine

✓The authors report the case of a 47-year-old woman who harbored a giant cell tumor at the T-5 level. She had undergone curettage of the tumor via a combined anterior and posterior approach at a regional hospital and was later referred to the authors' institution for treatment after the tumor recurred. On examination she exhibited progressive paraparesis and was nonambulatory due to cord compression caused by the tumor, which had invaded the spinal canal and extended to the right paravertebral muscles and right thoracic cavity. A spondylectomy was performed through a single posterior approach. The tumor, together with a portion of the dura mater, pleura, and muscles, was resected en bloc from T-4 to T-6. After resection, spinal reconstruction was performed by placement of an anterior titanium mesh cage as well as posterior pedicle screw and rod instrumentation. The patient's postoperative course was uneventful, and she exhibited substantial neurological recovery and became ambulatory. Two and a half years after surgery, the patient was tumor free.

En bloc resection of a recurrent giant cell tumor was successfully achieved through a single posterior approach. This surgical technique can be an effective option for this pathological condition, which is difficult to manage using other conventional treatment options including repeated curettage and radiotherapy.