Neurological function after total en bloc spondylectomy for thoracic spinal tumors

Application of contralateral osteotomy for the en bloc resection of paraspinal and spinal tumours: a report of three cases

We herein report the effectiveness of contralateral osteotomy of the pedicle and posterolateral elements for en bloc resection (COPPER) of paraspinal and spinal tumours. This surgical method allows for complete resection of the localized tumour in the lateral posterior lesion without removing the entire vertebral body, as in total en bloc spondylectomy. Complete resection of paraspinal and spinal tumours is challenging for spinal surgeons because of anatomical complexities. Although the COPPER method has been introduced as a less invasive surgical procedure for wide resection of spinal tumours, no studies have reported the usefulness of this technique. We identified three patients with paraspinal or spinal tumours who underwent wide resection using the COPPER method and reviewed their clinical, radiological, and pathological outcomes. In all cases, we resected the spinal and paraspinal tumours extending to the anterior column and extravertebral component using the modified COPPER method. All patients underwent en bloc resection with a negative margin. We report three cases of spinal and paraspinal tumours extending to the anterior column and extravertebral component.

En Bloc Surgery in the Thoracic Spine: Indications, Results, and Complications in a Series of Eighty-Five Patients Affected by Primary and Secondary Malignant Bone Tumors

BACKGROUND

En bloc resection remains the cornerstone treatment for malignant bone tumors affecting the spine. The thoracic spine poses unique challenges because of the proximity of crucial structures. This study assesses outcomes of patients who underwent en bloc spondylectomy for malignant bone tumors at the thoracic level.

METHODS

We retrospectively reviewed 85 cases of primary and secondary bone tumors in the thoracic spine, undergoing en bloc spondylectomy from 1996 to 2016. Evaluation encompassed clinical presentation, tumor characteristics, surgical outcomes, complications, survival, and recurrence.

RESULTS

Of 85 patients, 40 presented directly, whereas 45 had undergone previous intralesional surgery. Chondrosarcoma and chordoma comprised the most prevalent primary histologic types; thyroid and kidney carcinomas were the most frequent secondary tumors. Pain was reported in 75 patients at diagnosis. Margins were adequate in 54 cases and intralesional in 31. Immediate postoperative deaths amounted to 4. Major complications included substantial blood loss, neurologic deterioration, and paraplegia. The 5-year local recurrence-free survival was 58.7%, significantly influenced by the surgical margin: patients with wide margins experienced a 5-year local recurrence-free survival of 85.7%, whereas those with marginal and intralesional margins had rates of 56.7% and 45.6%, respectively; overall recurrence was 22.3%, with no notable disparities between previously treated and untreated patients. The 5-year overall survival was 63.2% and 56.2% for primary and secondary tumors, respectively. The overall survival was not significantly influenced by surgical margins.

CONCLUSIONS

Managing malignant thoracic bone tumors poses significant challenges. This study underscores the criticality of achieving adequate margins, particularly after previous intralesional approaches.

Axial Axis Metastasis

Axial axis metastasis remains a challenge for surgical as well as other treatment modalities, like chemotherapy, immunotherapy, and radiotherapy. It is unequivocal that surgery provides pain improvements and preservation of neurological status, but this condition remains when associated with radiotherapy and other treatment modalities. In this review, we emphasize the current forms of surgical treatment in the different regions of the spine and pelvis. The evident possibility of percutaneous treatments is related to early or late cases, and in cases in which there are greater risks and instability to conventional surgeries associated with radiotherapy and have been shown to be the appropriate option for local control of metastatic disease.

Complication Avoidance in Surgical Management of Vertebral Column Tumors

The surgical management of spinal tumors has grown increasingly complex as treatment algorithms for both primary bone tumors of the spine and metastatic spinal disease have evolved in response to novel surgical techniques, rising complication rates, and additional data concerning adjunct therapies. In this review, we discuss actionable interventions for improved patient safety in the operative care for spinal tumors. Strategies for complication avoidance in the preoperative, intraoperative, and postoperative settings are discussed for approach-related morbidities, intraoperative hemorrhage, wound healing complications, cerebrospinal fluid (CSF) leak, thromboembolism, and failure of instrumentation and fusion. These strategies center on themes such as pre-operative imaging review and medical optimization, surgical dissection informed by meticulous attention to anatomic boundaries, and fastidious wound closure followed by thorough post-operative care.

Neurologic Complications of Preoperative Embolization of Spinal Metastasis: A Systemic Review of the Literature Identifying Distinct Mechanisms of Injury

BACKGROUND

Preoperative embolization of spinal metastases may improve outcomes of resection by reducing surgical blood loss and operative time. Neurologic complications are rarely reported and the mechanisms leading to injury are poorly described.

METHODS

We present 2 illustrative cases of embolization-related neurologic injury from distinct mechanisms and the findings of a systemic literature review of similar complications according to the PRISMA guidelines.

RESULTS

A 77-year-old man with a history of renal cell carcinoma presented with gait dyscoordination and arm pain/weakness. Magnetic resonance imaging showed a C7/T1 mass causing severe compression of the C7/T1 roots and spinal cord. After embolization and tumor resection/fusion, lethargy prompted imaging showing multiple posterior circulation infarcts believed to be secondary to reflux of embolic particles. A 75-year-old man with renal cell carcinoma presented with L1 level metastasis causing conus compression and experienced paraplegia after superselective particle embolization presumed to be secondary to flow disruption of the artery of Adamkiewicz. Analysis of the literature yielded 6 articles reporting instances of cranial infarction/ischemia occurring in 10 patients, 12 articles reporting spinal cord ischemia/infarction occurring in 17 patients, and 5 articles reporting symptomatic postembolization tumoral swelling in 5 patients.

CONCLUSIONS

Neurologic injury is a risk of preoperative embolization of spinal metastasis from either compromise of spinal cord vascular supply or cranial stroke from reflux of embolic particles. Postprocedural tumor swelling rarely leads to clinical deficit. Awareness of these complications and the presumed mechanisms of injury may aid clinicians in implementing interventions and in counseling patients before treatment.

Unilateral Nerve Root Ligation for Multilevel Vertebral Column Resection After Fixed Post-infectious Deformity

Kyphotic deformity is a well-recognized complication of thoracic vertebral osteomyelitis, often requiring multi-level vertebral column resection for mobilization of the spine and reduction of the deformity. We present a case of severe post-infectious kyphosis treated with multi-level vertebral column resection via a unilateral approach. We obtained excellent decompression and deformity correction without neurologic decline. We review relevant literature regarding spinal cord blood supply and known potential complication of nerve root ligations.

The Safety Profile of Intentional or Iatrogenic Sacrifice of the Artery of Adamkiewciz and Its Vicinity's Spinal Segmental Arteries: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

There is paucity of consensus on whether (1) the artery of Adamkiewicz (AoA) and (2) the number of contiguous segmental spinal arteries (SSAs) that can be safely ligated without causing spinal cord ischemia. The objective of this review is to determine the risk of motor neurological deficits from iatrogenic sacrifice of the (1) AoA and (2) its vicinity's SSAs.

METHODS

Systematic review of the spine and vascular surgery was carried out in accordance to PRISMA guidelines. Outcomes in terms of risk of postoperative motor neurological deficit with occlusion of the AoA, bilateral contiguous SSAs, or unilateral contiguous SSAs were analyzed.

RESULTS

Ten articles, all retrospective case series, were included. Three studies (total N = 50) demonstrated a postoperative neurological deficit risk of 4.0% when the AoA is occluded. When 1 to 6 pairs of SSAs (without knowledge of AoA location) were ligated, the postoperative neurological deficit risk was 0.6%, as compared with 5.4% when more than 6 bilateral pairs of SSAs were ligated (relative risk [RR] = 0.105, 95% CI 0.013-0.841, P = .0337). For unilateral ligation of SSAs of two to nine levels, the risk of postoperative neurological deficit does not exceed 1.3%.

CONCLUSION

The current best evidence indicates that (1) occlusion of the AoA and (2) occlusion of up to 6 pairs of SSAs is associated with a low risk of postoperative neurological deficit. This limited number of low quality studies restrict the ability to draw definitive conclusions. Ligation of AoA and SSAs should only be undertaken when absolutely required to mitigate the small but devastating risk of paralysis.

Surgical Strategies for Chordoma

Chordomas are rare tumors of the axial skeleton whose slow growth belies a relentless tumor with a propensity for recurrence and late metastasis. Local control remains an issue with chordoma in spite of aggressive operative management. High local failure rates have led to the exploration of alternative methods of treatment. Radiation continues to gain acceptance as an adjuvant to surgery and, in some cases, as a standalone treatment. However, the use of radiation remains controversial, and operative management remains the standard of care in spite of relatively high morbidity.

En bloc vertebrectomy for the treatment of spinal lesions. Five years of experience in a single institution: a case series

OBJECTIVES

The objective of this study is to describe the experience of a Brazilian public university hospital regarding the treatment of metastatic or benign spine lesions with en bloc vertebrectomy of the thoracic and lumbar spines.

METHODS

This study was a retrospective case series and included all medical records of patients with benign aggressive, primary malignant, or metastatic spine lesions who underwent en bloc vertebrectomy from 2010 to 2015.

RESULTS

A total of 17 patients were included in the analysis. Most of them (71%) were indicated for surgery based on an oncologic resection for localized disease cure. Overall, 10 of the 17 patients (59%) underwent vertebrectomy via an isolated posterior approach using the technique described by Roy-Camille et al. and Tomita et al., while 7 patients (41%) underwent double approach surgeries. Of the 17 patients who underwent the en bloc resection, 8 are still alive and in the outpatient follow-up (47%), and almost all patients with metastatic lesions (8/9) died. The average survival time following the surgical procedure was 23.8 months. Considering the cases of metastatic lesions and the cases of localized disease (malignant or benign aggressive disease) separately, we observed an average survival time of 15 months and 47.6 months respectively.

CONCLUSION

This study demonstrates and reinforces the reproducibility of the en bloc vertebrectomy technique described by Tomita et al.

Predictive value of pedicle involvement with MRI in spine metastases

OBJECTIVES

The study aimed to retrospectively evaluate the accuracy and value of magnetic resonance imaging (MRI) in predicting pedicle involvement for patients with spine metastases.

METHODS

Forty-five patients with a vertebral metastasis encroaching at least one pedicle were studied using MRI before surgery and regularly after surgery. Patients were categorized on the basis of their numbers of pedicle involvement (Group 1: one pedicle was involved, n = 23; Group 2: two pedicles were involved, n = 22). The diagnostic accuracy was calculated, and comparisons of intraoperative blood loss and recurrence rate between the two groups were performed.

RESULTS

The overall performance of MRI in predicting the pedicle involvement was as follows: accuracy, 94.4%; sensitivity, 95.5%; and specificity, 91.3%. Less intraoperative blood loss was observed for Group 1 compared with Group 2 (1,661 ± 672 ml and 2,173 ± 790 ml, respectively, P = 0.024). Tumor relapse occurred in 8.7% (2/23) of Group 1 and in 22.7% (5/22) of Group 2 with median recurrence free survival time 14 and 9 months, respectively.

CONCLUSIONS

MRI is a reliable approach to assess pedicle involvement. It has potential for use in the evaluation of the clinical characteristics of patients with spine metastases.

[Total en bloc spondylectomy for spinal tumours: Technical aspects and surgical details]

OBJECTIVE

To describe the specific surgical details and report the lessons learned with a series of patients suffering from spinal tumours that underwent total en bloc spondylectomy (TES).

METHODS

A retrospective case series review is presented, together with an analysis of the clinical and technical variables, as well as the outcomes.

RESULTS

A total of 10 patients underwent TES (2000-2016) for primary (osteosarcoma, chondrosarcoma, fibrosarcoma and chordoma) and secondary spinal tumours (lung, breast, thyroid, oesophagus, and meningioma metastases). According to the Tomita classification, 2 patients had intra-compartmental tumours, and the rest presented as extra-compartmental. All patients experienced an improvement in their pain level after surgery. Nine patients preserved ambulation post-operatively and one patient developed paraplegia. Six patients needed subsequent operations for wound debridement, tumour recurrence, or revision of the fixation. Other complications included pneumothorax, pleural effusion and venous thrombosis. Four patients remain alive (4 months to 15 years follow-up). The rest died due to primary tumour progression (6.5 months to 12 years). A detailed description of the surgical steps, tips, and pitfalls is provided. Modifications of the technique and adjuncts to resection are commented on. Observation of some considerations (selection of candidates, careful blunt vertebral dissection, strict blood loss control, careful handling of the spinal cord, and maintenance of the radical resection concept at all stages) is key for a successful operative performance.

CONCLUSION

TES is a paradigmatic operation, in which the concept of radical resection provides functional effectiveness and improves survival in selected patients suffering from spinal tumours. Our preliminary experience allows us to highlight some specific and relevant features, especially those favouring a simpler and safer operation.

Total en bloc spondylectomy for locally aggressive vertebral hemangioma causing neurological deficits

Vertebral hemangiomas are common; however, aggressive vertebral hemangiomas with extraosseous extensions causing neurological deficits are rare. The treatment for this subtype of hemangioma remains controversial, since there are few reports on long-term clinical outcomes or tumor recurrence rates. We describe a case of aggressive vertebral hemangioma treated by total en bloc spondylectomy, with a literature review focusing on long-term recurrence. A 52-year-old male with a two-month history of numbness in the bilateral lower extremities was referred to our hospital. Imaging studies showed a tumor originating in the T9 vertebra and extending to the T8 and T10 vertebrae, with extraosseous extension causing spinal-cord compression. Ten months after onset, the patient presented with progressive paraparesis and hypalgesia. Total en bloc spondylectomy was performed, and pathology was consistent with cavernous hemangioma. Motor and sensory deficits improved significantly, and no signs of recurrence are seen at 2.5 years after operation. A review of literature revealed a recurrence rate of 12.7% (10/79 cases). The available evidence indicates satisfactory long-term outcomes for total tumor resection without adjuvant radiotherapy.

Multilevel en bloc spondylectomy for tumors of the thoracic and lumbar spine is challenging but rewarding

BACKGROUND

Over the years, en bloc spondylectomy has proven its efficacy in controlling spinal tumors and improving survival rates. However, there are few reports of large series that critically evaluate the results of multilevel en bloc spondylectomies for spinal neoplasms.

QUESTIONS/PURPOSES

Using data from a large spine tumor center, we answered the following questions: (1) Does multilevel total en bloc spondylectomy result in acceptable function, survival rates, and local control in spinal neoplasms? (2) Is reconstruction after this procedure feasible? (3) What complications are associated with this procedure? (4) is it possible to achieve adequate surgical margins with this procedure?

METHODS

We retrospectively investigated 38 patients undergoing multilevel total en bloc spondylectomy by a single surgeon (AL) from 1994 to 2011. Indications for this procedure were primary spinal sarcomas, solitary metastases, and aggressive primary benign tumors involving multiple segments of the thoracic or lumbar spine. Patients had to be medically fit and have no visceral metastases. Analysis was by chart and radiographic review. Margin quality was classified into intralesional, marginal, and wide. Radiographs, MR images, and CT scans were studied for local recurrence. Graft healing and instrumentation failures at subsequent followup were assessed. Complications were divided into major or minor and further classified as intraoperative and early and late postoperative. We evaluated the oncologic status using cumulative disease-specific and metastases-free survival analysis. Minimum followup was 24 months (mean, 39 months; range, 24-124 months).

RESULTS

Of the 38 patients, 34 (89%) were alive and walking without support at final followup. Thirty-one (81%) had no evidence of disease. Two patients died postoperatively and another two died of systemic disease (without local recurrence). Only three patients (8%) had a local recurrence. There were 14 major complications and 22 minor complications in 25 patients (65%). Only one patient required revision of implants secondary to mechanical failure. Two cases of cage subsidence were noted but had no clinical significance. Wide margins were achieved in nine patients (23%), marginal in 25 (66%), and intralesional in four (11%).

CONCLUSIONS

In patients with multisegmental spinal tumors, oncologic resections were achieved by multilevel en bloc spondylectomy and led to an acceptable survival rate with reasonable local control. Multilevel en bloc surgery was associated with a high complication rate; however, most patients recovered from their complications. Although the surgical procedure is challenging, our encouraging mid-term results clearly favor and validate this technique.

LEVEL OF EVIDENCE

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

Surgical site infection after total en bloc spondylectomy: risk factors and the preventive new technology

BACKGROUND CONTEXT

Surgical site infection (SSI) associated with instruments remains a serious and common complication in patients who undergo total en bloc spondylectomy (TES). It is very important that the risk factors for SSI are known to prevent it.

PURPOSE

The purpose of the study was to identify independent risk factors for SSI after TES and evaluate the positive effect of iodine-supported spinal instruments in the prevention of SSI after TES.

STUDY DESIGN

This is a retrospective clinical study.

PATIENT SAMPLE

One hundred twenty-five patients who underwent TES for vertebral tumor were evaluated.

OUTCOME MEASURES

Incidence rate of SSI, risk factors for SSI after TES, and safety of iodine-supported spinal instruments were the outcome measures.

METHODS

Risk factors for SSI were analyzed using logistic regression. In recent 69 patients with iodine-supported spinal instruments, the thyroid hormone levels in the blood were examined to confirm if iodine from the implant influenced thyroid function. Postoperative radiological evaluations were performed regularly.

RESULTS

The rate of SSI was 6.4% (8/125 patients). By multivariate logistic regression, combined anterior and posterior approach and nonuse of iodine-supported spinal instruments were associated with an increased risk of SSI. The rate of SSI without iodine-supported spinal instruments was 12.5%, whereas the rate with iodine-supported spinal instruments was 1.4%. This difference was statistically significant. There were no detected abnormalities of thyroid gland function with the use of iodine-supported instruments. Among the 69 patients with iodine-supported spinal instruments, 2 patients required additional surgery because of instrument failure. However, there were no obvious involvements with the use of iodine-supported spinal instruments.

CONCLUSIONS

This study identified combined anterior and posterior approach and nonuse of iodine-supported spinal instruments to be independent risk factors for SSI after TES. Iodine-supported spinal instrument was extremely effective for prevention of SSI in patients with compromised status, and it had no detection of cytotoxic or adverse effects on the patients.

Four- and five- level en bloc spondylectomy for malignant spinal tumors

STUDY DESIGN

Retrospective study.

OBJECTIVE

To report results of 4- and 5-level en bloc spondylectomy (EBS) in the treatment of malignant spinal tumors.

SUMMARY OF BACKGROUND DATA

EBS is widely used to avoid local recurrence in the treatment of spinal malignant tumors. Four- and 5-level EBS are aggressive procedures associated with complications and morbidity.

METHODS

We conducted a retrospective study of all patients treated with minimum 4-level EBS. Patient and surgical data were noted. Radiographs, magnetic resonance images, and computed tomographic scans were studied for local recurrence, graft, and instrumentation failures at subsequent follow-up. Type of excision was classified into intralesional, marginal, and wide margins. Complications were divided into major or minor and were further classified as intraoperative, early, and late postoperative. At the last follow-up, the patients were classified as alive with no evidence of local or systemic disease, alive with evidence of local or systemic disease or both, dead with evidence of local disease, or systemic disease or both, and dead without evidence of local and systemic disease.

RESULTS

Nine patients were identified who required a minimum 4-level en bloc resection. Five males and 4 females. Average age was 41.66 years (11-66). There were 8 primary malignant tumors: 3 chordomas, 3 osteosarcomas, 1 chondrosarcoma, 1 primary lung tumor and 1 metastatic alveolar soft part sarcoma. Six were operated with 4-level en bloc and 3 with 5 levels. The mean surgical time was 713 minutes and estimated blood loss was 4.5 L. Mean follow-up was 27.7 months (8-84). At the last follow-up, 6 patients were alive with no evidence of local or systemic disease, 1 alive with evidence of systemic disease, 1 dead with evidence of local disease, or systemic disease or both, and 1 DNLS. Only 1 (11%) patient had a local recurrence. Three patients with Frankel D had full neurological recovery. Histopathological assessment showed marginal margins in 7 patients and wide in 2. There were 9 major and 9 minor complications in 7 patients. Five of 7 patients (71%) with complications, had fully recovered from their complications at the last follow-up.

CONCLUSION

Multilevel EBS, can be offered to a patient to prevent local recurrence of disease. Even in experienced hands, the risks of intra- and postoperative complications are high (78%). However, most of the patients with complications, recovered completely (71%). Although the surgery itself may prove beneficial, patients should be well informed regarding the morbidity associated with it.

LEVEL OF EVIDENCE

4.

Spinal intradural myxoid chondrosarcoma

The authors present a rare case of intradural extramedullary spinal chondrosarcoma. This 38-year-old man presented with urinary retention and lower-limb weakness. Magnetic resonance imaging demonstrated a thoracic intradural extramedullary spinal tumor, which was resected. Histopathology revealed a meningeal myxoid chondrosarcoma. Despite adjuvant radiotherapy, the patient had multiple recurrences and metastases and died 18 months following his first surgery. The management of the rare entity of spinal canal chondrosarcoma is discussed.

Two-stage multilevel en bloc spondylectomy with resection and replacement of the aorta

OBJECTIVE

We report a case of multilevel spondylectomy in which resection and replacement of the adjacent aorta were done. Although spondylectomy is nowadays an established technique, no report on a combined aortic resection and replacement has been reported so far.

METHODS

The case of a 43-year-old man with a primary chondrosarcoma of the thoracic spine is presented. The local pathology necessitated resection of the aorta. We did a two-stage procedure with resection and replacement of the aorta using a heart-lung machine followed by secondary tumor resection and spinal reconstruction.

RESULTS

The procedure was successful. A tumor-free margin was achieved. The patient is free of disease 48 months after surgery.

CONCLUSION

En bloc spondylectomy in combination with aortic resection is feasible and might expand the possibility of producing tumor-free margins in special situations.

Modified total en bloc spondylectomy for thoracolumbar spinal tumors via a single posterior approach

PURPOSE

The objectives of this study were to describe our surgical management with a modified total en bloc spondylectomy (TES) and to evaluate the clinical effects in patients with thoracolumbar tumors.

METHODS

Sixteen consecutive patients with thoracolumbar neoplasms underwent a modified TES via single posterior approach followed by dorsoventral reconstruction from December 2008 to July 2011. Details of the modified technique were described and the patients' clinical information was retrospectively reviewed and analyzed.

RESULTS

Significant improvements in neurological function were achieved in most of the patients. Local pain or radicular leg pain was relieved postoperatively. The mean operation time was 7.2 h, with an average blood loss of 2,300 ml. No major complications, instrumentation failure or local recurrence was found at the final follow-up. Five patients died of the disease during mean 14-month (3.0-23) follow-up.

CONCLUSIONS

The modified TES with a single posterior approach is feasible, safe and effective for thoracolumbar spine tumors.

Late instrumentation failure after total en bloc spondylectomy

Object

The object of this study was to investigate failures after spinal reconstruction following total en bloc spondylectomy (TES), related factors, and sequelae arising from such failures in patients with malignant spinal tumors.

Methods

Fifteen patients (12 males and 3 females, with a mean age of 46.5 years) with malignant spinal tumors who underwent TES and survived for more than 1 year were included in this analysis (mean follow-up 41.5 months). Seven patients had primary tumors, including giant cell tumors in 4 patients, chordoma in 2, and Ewing sarcoma in 1. Eight patients had metastatic tumors, including thyroid cancer in 6 and renal cell cancer and malignant fibrous histiocytoma in 1 patient each. Seven patients without prominent paravertebral extension of the tumor were treated using a posterior approach alone, and 8 patients who exhibited prominent anterior or anterolateral extension of the tumors into the thoracic or abdominal cavity were treated using a combined anterior and posterior approach. Spinal reconstruction after tumor resection was performed using a combination of anterior structural support and posterior instrumentation. The relationship between instrumentation failure and clinical and radiographic factors, including age, sex, history of previous surgery, preoperative radiotherapy, tumor histology, tumor level, surgical approach, number of resected vertebrae, rod diameter, number of instrumented vertebrae, and cage subsidence, was investigated.

Results

Six patients (40%) with spinal instrumentation failure were identified: rod breakage occurred in 3 patients, and breakage of both the rod and the cage, combined cage breakage and screw back-out, and endplate fracture arising from cage subsidence occurred in 1 patient each. All of these patients experienced acute or chronic back pain, but only 1 patient with a tumor recurrence experienced neurological deterioration upon instrumentation failure. Cage subsidence (≥ 5 mm), preoperative irradiation, and the number of instrumented vertebrae (≤ 4 vertebrae) were significantly related to late instrumentation failure.

Conclusions

Late instrumentation failure was a frequent complication after TES. Although patients with instrumentation failure experienced back pain, the neurological sequelae were not catastrophic. For prevention, meticulous preparation of the graft site and a longer posterior fixation should be considered.