Spinal pelvic reconstruction after total sacrectomy for en bloc resection of a giant sacral chordoma. Technical note

Nerve Root Sparing En Bloc Resection of Sacral Chondrosarcoma: Technical Note and Review of the Literature

BACKGROUND

Total en bloc sacrectomy provides the best long-term local control for large primary bony sacral tumors, but often requires lumbosacral nerve root sacrifice leading to loss of ambulation and/or bowel, bladder, and/or sexual dysfunction. Nerve-sparing techniques may be an option for some patients that avoid these outcomes and accordingly improve postoperative quality of life.

OBJECTIVE

To describe the technique for a posterior-only en bloc hemisacrectomy with maximal nerve root preservation and to summarize the available literature.

METHODS

A 38-yr-old woman with a 7.7 × 5.4 × 4.5 cm biopsy-proven grade 2 chondrosarcoma involving the left L5-S2 posterior elements underwent a posterior-only left hemisacrectomy tri-rod L3-pelvis fusion. A systematic review of the English literature was also conducted to identify other descriptions of high sacrectomy with distal sacral nerve root preservation.

RESULTS

Computer-aided navigation facilitated an extracapsular resection that allowed preservation of the left-sided L5 and S3-Co roots. Negative margins were achieved and postoperatively the patient retained ambulation and good bowel/bladder function. Imaging at 9-mo follow-up showed no evidence of recurrence. The systematic review identified 4 prior publications describing 6 total patients who underwent nerve-sparing sacral resection. Enneking-appropriate resection was only obtained in 1 case though.

CONCLUSION

Here we describe a technique for distal sacral nerve root preservation during en bloc hemisacrectomy for a primary sacral tumor. Few prior descriptions exist, and the present technique may help to reduce the neurological morbidity of sacral tumor surgery.

Team Approach: Oncologic Sacrectomy

Oncologic sacrectomy is used in the curative treatment of patients with primary sacral malignancies or select locally invasive visceral malignancies. A systematic surgical approach involves preoperative imaging, diagnosis, and multidisciplinary surgical execution. Close collaboration with pediatric, medical, and radiation oncology colleagues is often necessary to individualize treatment plans.

Compassionate use of a custom 3D-printed sacral implant for revision of failing sacrectomy: case report

Reconstruction of the spinopelvic continuity after sacral resection for primary sacral tumors remains challenging. Complex anatomical and biomechanical factors of this transition zone may be addressed with the advancement of 3D-printed implants. Here, the authors report on a 67-year-old patient with a sacral chordoma who initially underwent total en bloc sacrectomy followed by standard spinopelvic reconstruction. Pseudarthrosis and instrumentation failure of the lumbosacral junction construct subsequently developed. A custom 3D-printed sacral prosthesis was created using high-resolution CT images. Emergency Food and Drug Administration approval was obtained, and the custom device was implanted as a salvage reconstruction surgery. Made of porous titanium mesh, the custom artificial sacrum was placed in the defect based on the anticipated osteotomic planes and was fixed with a screw-rod system along with a fibular bone strut graft. At the 18-month follow-up, the patient was disease free and walking short distances with assistance. CT revealed excellent bony incorporation into the graft.The use of a custom 3D-printed prosthesis in spinal reconstruction has been rarely reported, and its application in sacral reconstruction and long-term outcome are novel. While the implant was believed to be critical in endowing the region with enough biomechanical stability to promote healing, the procedure was difficult and several key learning points were discovered along the way.

Reconstruction of the pelvic ring after total en bloc sacrectomy using a 3D-printed sacral endoprosthesis with re-establishment of spinopelvic stability: a retrospective comparative study

AIMS

The aim of this study was to describe the use of 3D-printed sacral endoprostheses to reconstruct the pelvic ring and re-establish spinopelvic stability after total en bloc sacrectomy (TES) and to review its outcome.

PATIENTS AND METHODS

We retrospectively reviewed 32 patients who underwent TES in our hospital between January 2015 and December 2017. We divided the patients into three groups on the basis of the method of reconstruction: an endoprosthesis group (n = 10); a combined reconstruction group (n = 14), who underwent non-endoprosthetic combined reconstruction, including anterior spinal column fixation; and a spinopelvic fixation (SPF) group (n = 8), who underwent only SPF. Spinopelvic stability, implant survival (IS), intraoperative haemorrhage rate, and perioperative complication rate in the endoprosthesis group were documented and compared with those of other two groups.

RESULTS

The mean overall follow-up was 22.1 months (9 to 44). In the endoprosthesis group, the mean intraoperative hemorrhage was 3530 ml (1600 to 8100). Perioperative complications occurred in two patients; both had problems with wound healing. After a mean follow-up of 17.7 months (12 to 38), 9/10 patients could walk without aids and 8/10 patients were not using analgesics. Imaging evidence of implant failure was found in three patients, all of whom had breakage of screws and/or rods. Only one of these, who had a local recurrence, underwent re-operation, at which solid bone-endoprosthetic osseointegration was found. The mean IS using re-operation as the endpoint was 32.5 months (95% confidence interval 23.2 to 41.8). Compared with the other two groups, the endoprosthesis group had significantly better spinopelvic stability and IS with no greater intraoperative haemorrhage or perioperative complications.

CONCLUSION

The use of 3D-printed endoprostheses for reconstruction after TES provides reliable spinopelvic stability and IS by facilitating osseointegration at the bone-implant interfaces, with acceptable levels of haemorrhage and complications. Cite this article: Bone Joint J 2019;101-B:880-888.

The extended posterior approach for resection of sacral tumours

PURPOSE

The conventional posterior approach is mostly advocated for excision of sacral tumours below S2. We describe an operative technique of single-stage en bloc resection of sacral tumours, extending up to S1, through an extended posterior approach.

METHOD

Nine patients, who had undergone resection of sacral tumours, by the described technique formed the basis of this study. Four patients had chordomas, whereas schwannoma, neurilemmoma, giant-cell tumour, malignant paraganglioma and recurrent Ewing's sarcoma were seen in one patient each. They were followed up at regular intervals with a mean follow-up of 45.4 months. Perioperative complications, their functional and oncological outcomes at final follow-up were analysed.

RESULT

None of the patients had any perioperative complications like uncontrolled haemorrhage, injury to the rectum, deep vein thrombosis or pulmonary embolism. One patient had a superficial wound infection which subsided with regular dressing, and another patient developed a wound breakdown that required an additional flap procedure. At final follow-up, six patients were able to walk without any assistive devices, six patients had normal bladder function, and five patients had normal bowel function. Five patients did not have any recurrence at final follow-up, whereas two were alive with the disease and two had died.

CONCLUSION

The reported technique allows en bloc resection of sacral tumours up to S1, through a posterior-only approach. It is less invasive with minimal morbidity. The functional and oncological outcomes are similar to those reported by other investigators. These slides can be retrieved from electronic supplementary material.

[Development and current situation of reconstruction methods following total sacrectomy]

Objective

To review the development of the reconstruction methods following total sacrectomy, and to provide reference for finding a better reconstruction method following total sacrectomy.

Methods

The case reports and biomechanical and finite element studies of reconstruction following total sacrectomy at home and abroad were searched. Development and current situation were summarized.

Results

After developing for nearly 30 years, great progress has been made in the reconstruction concept and fixation techniques. The fixation methods can be summarized as the following three strategies: spinopelvic fixation (SPF), posterior pelvic ring fixation (PPRF), and anterior spinal column fixation (ASCF). SPF has undergone technical progress from intrapelvic rod and hook constructs to pedicle and iliac screw-rod systems. PPRF and ASCF could improve the stability of the reconstruction system.

Conclusion

Reconstruction following total sacrectomy remains a challenge. Reconstruction combining SPF, PPRF, and ASCF is the developmental direction to achieve mechanical stability. How to gain biological fixation to improve the long-term stability is an urgent problem to be solved.

Effects of primary and recurrent sacral chordoma on the motor and nociceptive function of hindlimbs in rats: an orthotopic spine model

OBJECTIVE Chordoma is a slow-growing, locally aggressive cancer that is minimally responsive to conventional chemotherapy and radiotherapy and has high local recurrence rates after resection. Currently, there are no rodent models of spinal chordoma. In the present study, the authors sought to develop and characterize an orthotopic model of human chordoma in an immunocompromised rat. METHODS Thirty-four immunocompromised rats were randomly allocated to 4 study groups; 22 of the 34 rats were engrafted in the lumbar spine with human chordoma. The groups were as follows: UCH1 tumor-engrafted (n = 11), JHC7 tumor-engrafted (n = 11), sham surgery (n = 6), and intact control (n = 6) rats. Neurological impairment of rats due to tumor growth was evaluated using open field and locomotion gait analysis; pain response was evaluated using mechanical or thermal paw stimulation. Cone beam CT (CBCT), MRI, and nanoScan PET/CT were performed to evaluate bony changes due to tumor growth. On Day 550, rats were killed and spines were processed for H & E-based histological examination and immunohistochemistry for brachyury, S100β, and cytokeratin. RESULTS The spine tumors displayed typical chordoma morphology, that is, physaliferous cells filled with vacuolated cytoplasm of mucoid matrix. Brachyury immunoreactivity was confirmed by immunostaining, in which samples from tumor-engrafted rats showed a strong nuclear signal. Sclerotic lesions in the vertebral body of rats in the UCH1 and JHC7 groups were observed on CBCT. Tumor growth was confirmed using contrast-enhanced MRI. In UCH1 rats, large tumors were observed growing from the vertebral body. JHC7 chordoma-engrafted rats showed smaller tumors confined to the bone periphery compared with UCH1 chordoma-engrafted rats. Locomotion analysis showed a disruption in the normal gait pattern, with an increase in the step length and duration of the gait in tumor-engrafted rats. The distance traveled and the speed of rats in the open field test was significantly reduced in the UCH1 and JHC7 tumor-engrafted rats compared with controls. Nociceptive response to a mechanical stimulus showed a significant (p < 0.001) increase in the paw withdrawal threshold (mechanical hypalgesia). In contrast, the paw withdrawal response to a thermal stimulus decreased significantly (p < 0.05) in tumor-engrafted rats. CONCLUSIONS The authors developed an orthotopic human chordoma model in rats. Rats were followed for 550 days using imaging techniques, including MRI, CBCT, and nanoScan PET/CT, to evaluate lesion progression and bony integrity. Nociceptive evaluations and locomotion analysis were performed during follow-up. This model reproduces cardinal signs, such as locomotor and sensory deficits, similar to those observed clinically in human patients. To the authors' knowledge, this is the first spine rodent model of human chordoma. Its use and further study will be essential for pathophysiology research and the development of new therapeutic strategies.

One-step reconstruction with a 3D-printed, custom-made prosthesis after total en bloc sacrectomy: a technical note

BACKGROUND

Surgeries for primary malignancies involving upper sacrum require total en bloc sacrectomy followed by complex mechanical reconstruction, which might be simplified by application of the three-dimensional (3D) printing technique.

PURPOSES

To describe the design of a 3D-printed custom-made prosthesis for reconstruction after total en bloc sacrectomy, the surgical technique, and the clinical and functional outcome of a patient.

METHODS

A 62-year-old patient with recurrent sacral chordoma was admitted in our center. One-stage total en bloc sacrectomy through posterior approach was planned, and a 3D-printed sacral prosthesis was prepared for reconstruction according to the anticipated osteotomic planes.

RESULTS

The patient received one-stage total en bloc sacrectomy through posterior approach followed by reconstruction with the 3D-printed sacral prosthesis. The whole procedure took 5 h, and intra-operative blood loss was 3400 ml. The patient recovered uneventfully and started ambulation at 3 weeks after surgery. An asymptomatic instrument failure was found radiographically at 8-month follow-up. At 1 year after surgery, the patient was disease free and could walk over short distance with crutches without pain or any mechanical instability.

CONCLUSIONS

The advantages of our reconstruction method included: (1) the prosthesis provided an optimal reconstruction of lumbosacral and pelvic ring by integrating spinal pelvic fixation, posterior pelvic ring fixation, and anterior spinal column fixation in one step and (2) its porous surface could induce bone ingrowth and might enhance stability. Although there was an instrumental failure, we considered that it could be one reconstructive option. More research is warranted focusing on the modification of locations, diameters, and quantity of screws and biomechanical characteristics. The long-term functional and bone in-growth outcome will be followed to validate the use of the prosthesis.

Pelvic Reconstruction Surgery Using a Dual-Rod Technique with Diverse U-Shaped Rods After Posterior En Bloc Partial Sacrectomy for a Sacral Tumor: 2 Case Reports and a Literature Review

BACKGROUND

Spinopelvic reconstruction after sacrectomy for a sacropelvic tumor can result in various complications and requires a highly complicated surgical technique. We report 2 cases of pelvic reconstruction surgery using diverse U-shaped rods (USRs) after partial sacrectomy.

CASE DESCRIPTION

A partial sacrectomy was performed for 2 different cases: one case was a metastatic sacral tumor and the other was a chordoma. In the first case, reconstruction was completed with an inner straight rod and an outer USR. The other patient underwent reconstruction using an inner USR and an outer straight rod. In both cases, there was no instrument failure, and the lumbosacral junction was reconstructed in balance. One of the patients died of metastatic lung cancer, and the other patient is alive and has experienced no other complications.

CONCLUSIONS

A pelvic reconstruction technique using diverse USRs showed good spinopelvic stability without complications. This technique may be a surgical option for reconstructive surgery after partial sacrectomy.

Reconstructive surgery using dual U-shaped rod instrumentation after posterior en bloc sacral hemiresection for metastatic tumor: case report

Despite various complications associated with sacrectomy to remove sacral tumors, total or en bloc sacrectomy has been suggested as the most appropriate surgical treatment in such cases. The authors present the case of a 62-year-old male patient with intractable back pain and voiding difficulty whom they treated with posterior en bloc sacral hemiresection followed by reconstruction using dual U-shaped rods. They report that good spinopelvic stability was achieved without complications. The authors conclude that this technique is relatively simple compared with other sacral reconstructive techniques and can prevent complications, including herniation.

Is total en bloc sacrectomy using a posterior-only approach feasible and safe for patients with malignant sacral tumors?

OBJECT In this study the authors' aim was to describe their experience with total en bloc sacrectomy using a posterioronly approach and to assess the outcome of patients with malignant sacral tumors who underwent this procedure at their center. METHODS The authors identified and retrospectively reviewed the records of 10 patients with malignant sacral tumors who underwent a total en bloc sacrectomy via a single posterior approach at their center. The pathological diagnosis was chordoma in 4 patients, chondrosarcoma in 1, osteosarcoma in 1, malignant schwannoma in 1, malignant giant cell tumor in 1, and Ewing's sarcoma in 2. Radiological examination revealed that the tumor involved S1-5 in 7 patients, S1-4 in 1, S1-3 in 1, and S1-2 in 1. RESULTS All 10 patients were stable during the perioperative period. The mean surgery duration was 282 minutes (range 250-310 minutes). The median estimated blood loss was 2595 ml (range 1500-3200 ml). All patients were followed up for 13-29 months (mean 22 months). Two patients had a local recurrence. Two patients died of disease, 1 patient was alive with disease, and 7 patients were alive without evidence of disease. Among the 8 surviving patients, 6 were able to walk without assistive devices, and 2 were able to walk with crutches. The total complication rate was 40% (4 of 10). Wound complications (deep infection and wound healing problems) occurred in 3 patients, and a distal deep vein thrombosis occurred in 1 patient. CONCLUSIONS Total en bloc sacrectomy using a posterior-only approach is feasible and safe in selected patients and is an important procedure for the treatment of primary malignant tumor involving the entire sacrum or only the top portion.

Spinal tumor surgery: management and the avoidance of complications

BACKGROUND

Complication avoidance is paramount to the success of any surgical procedure. In the case of spine tumor surgery, the risk of complications is increased because of the primary disease process and the radiotherapy and chemotherapeutics used to treat the disease. If complications do occur, then life-saving adjuvant treatment must be delayed or withheld until the issue is resolved, potentially impacting overall disease control.

METHODS

We reviewed the literature and our own best practices to provide recommendations on complication avoidance as well as the management of complications that may occur. Appropriate workup of suspected complications and treatment algorithms are also discussed.

RESULTS

Appropriate patient selection and a multidisciplinary workup are imperative in the setting of spinal tumors. Intraoperative complications may be avoided by employing proper surgical technique and an understanding of the pathological changes in anatomy. Major postoperative issues include wound complications and spinal reconstruction failure. Preoperative surgical planning must include postoperative reconstruction. Patients undergoing spinal tumor resection should be closely monitored for local tumor recurrence, recurrence along the biopsy tract, and for distant metastatic disease. Any suspected recurrence should be closely watched, biopsied if necessary, and promptly treated.

CONCLUSIONS

Because patients with spinal tumors are normally treated with a multidisciplinary approach, emphasis should be placed on the recognition of surgical complications beyond the surgical setting.

Pelvic reconstruction after subtotal sacrectomy for sacral chondrosarcoma using cadaveric and vascularized fibula autograft: Technical note

A novel method of spinopelvic ring reconstruction after partial sacrectomy for a chondrosarcoma is described. Chondrosarcoma is one of the most common primary malignant bone tumors, and en bloc resection is the mainstay of treatment. Involvement of the pelvis as well as the sacrum and lumbar spine can result in a technically difficult challenge for en bloc resection and for achievement of appropriate load-bearing reconstruction. After en bloc resection in their patient, the authors achieved reconstruction with a rod and screw construct including vascularized fibula graft as the main strut from the lumbar spine to the pelvis. Additionally, a cadaveric allograft strut was used as an adjunct for the pelvic ring. This is similar to a modified Galveston technique with vascularized fibula in place of the Galveston rods. The vascularized fibula provided appropriate biomechanical support, allowing the patient to return to independent ambulation. There was no tumor recurrence; neurological status remained stable; and the allograft construct integrated well and even increased in size on CT scans and radiographs in the course of a follow-up longer than 7 years.

A new type of reconstruction of the hemipelvis after Type 3 amputative sacrectomy using pedicled fibula

This is a technical note of pelvic reconstruction performed by an advanced multidisciplinary team. The authors report a new 3-stage reconstruction of the hemipelvis after Type 3 sacrectomy involving instrumented spinoiliac arthrodesis and pedicled fibula grafting in 2 patients.

The anterior stage of the procedure begins with a transabdominal approach to mobilize the viscera and to free up the tumor from the vessels. The posterior divisions of internal iliac vessels, the middle sacral vessels, and the lateral sacral vessels are then ligated. An anterior vertebrectomy is done at the appropriate level, followed by an anterior osteotomy through the lateral planed surgical margin of the sacrum close to the salvaged sacroiliac joint. The second stage includes a major sacral resection with lower-extremity amputation from the pubic symphysis through the intact side of the sacrum, ipsilateral pedicled fibula harvesting, and closure with an ipsilateral pedicled quadriceps flap. The final stage involves reconstruction with lumboiliac instrumentation. The pedicled fibular graft left from the second stage is then placed distally within the previously created iliopectineal docking site and proximally within the L-5 docking site.

The authors believe that this is a feasible and reproducible technique with theoretical advantages that have to be proved in the long-term follow-up.

[Chordoma]

PURPOSES

To review in the literature, all the epidemiological, clinical, radiological, histological and therapeutic data regarding chordomas as well as various notochordal entities: ecchordosis physaliphora, intradural and intraparenchymatous chordomas, benign notochordal cell tumors, parachordomas and extra-axial chordomas. To identify different types of chordomas, including familial forms, associations with tuberous sclerosis, Ollier's disease and Maffucci's syndrome, forms with metastasis and seeding. To assess the recent data regarding molecular biology and progress in targeted therapy. To compare the different types of radiotherapy, especially protontherapy and their therapeutic effects. To review the largest series of chordomas in their different localizations (skull base, sacrum and mobile spine) from the literature.

MATERIALS

The series of 136 chordomas treated and followed up over 20 years (1972-2012) in the department of neurosurgery at Lariboisière hospital is reviewed. It includes: 58 chordomas of the skull base, 47 of the craniocervical junction, 23 of the cervical spine and 8 from the lombosacral region. Similarly, 31 chordomas in children (less than 18 years of age), observed in the departments of neurosurgery of les Enfants-Malades and Lariboisière hospitals, are presented. They were observed between 1976 and 2010 and were located intracranially (n=22 including 13 with cervical extension), 4 at the craniocervical junction level and 5 in the cervical spine.

METHODS

In the entire Lariboisière series and in the different groups of localization, different parameters were analyzed: the delay of diagnosis, of follow-up, of occurrence of metastasis, recurrence and death, the number of primary patients and patients referred to us after progression or recurrence and the number of deaths, recurrences and metastases. The influence of the quality of resection (total, subtotal and partial) on the prognosis is also presented. Kaplan-Meier actuarial curves of overall survival and disease free survival were performed in the entire series, including the different groups of localization based on the following 4 parameters: age, primary and secondary patients, quality of resection and protontherapy. In the pediatric series, a similar analysis was carried-out but was limited by the small number of patients in the subgroups.

RESULTS

In the Lariboisière series, the mean delay of diagnosis is 10 months and the mean follow-up is 80 months in each group. The delay before recurrence, metastasis and death is always better for the skull base chordomas and worse for those of the craniocervical junction, which have similar results to those of the cervical spine. Similar figures were observed as regards the number of deaths, metastases and recurrences. Quality of resection is the major factor of prognosis with 20.5 % of deaths and 28 % of recurrences after total resection as compared to 52.5 % and 47.5 % after subtotal resection. This is still more obvious in the group of skull base chordomas. Adding protontherapy to a total resection can still improve the results but there is no change after subtotal resection. The actuarial curve of overall survival shows a clear cut in the slope with some chordomas having a fast evolution towards recurrence and death in less than 4 years and others having a long survival of sometimes more than 20 years. Also, age has no influence on the prognosis. In primary patients, disease free survival is better than in secondary patients but not in overall survival. Protontherapy only improves the overall survival in the entire series and in the skull base group. Total resection improves both the overall and disease free survival in each group. Finally, the adjunct of protontherapy after total resection is clearly demonstrated. In the pediatric series, the median follow-up is 5.7 years. Overall survival and disease free survival are respectively 63 % and 54.3 %. Factors of prognosis are the histological type (atypical forms), localization (worse for the cervical spine and better for the clivus) and again it will depend on the quality of resection.

CONCLUSIONS

Many different pathologies derived from the notochord can be observed: some are remnants, some may be precursors of chordomas and some have similar features but are probably not genuine chordomas. To-day, immuno-histological studies should permit to differentiate them from real chordomas. Improving knowledge of molecular biology raises hopes for complementary treatments but to date the quality of surgical resection is still the main factor of prognosis. Complementary protontherapy seems useful, especially in skull base chordomas, which have better overall results than those of the craniocervical junction and of the cervical spine. However, we are still lacking an intrinsic marker of evolution to differentiate the slow growing chordomas with an indolent evolution from aggressive types leading rapidly to recurrence and death on which more aggressive treatments should be applied.

Surgical resection and reconstruction after resection of tumors involving the sacropelvic region

OBJECTIVES

Surgical management of tumors in the sacropelvic region is a challenging field of spine surgery because of the region's complex local anatomy and biomechanics. Recent developments in anesthesia and intensive care have allowed us to perform extended surgeries focused on the en bloc resection of sacropelvic tumors. Various techniques for the resection and for the reconstruction were published in the last decade.

METHODS

Sacropelvic tumor resection techniques and methods for the biomechanical and soft-tissue reconstruction are reviewed in this paper.

RESULTS

The literature data is based on case reports and case-series. Several different techniques were developed for the lumbopelvic stabilization after sacropelvic tumor resection according to three different reconstruction principles (spinopelvic fixation (SPF), posterior pelvic ring fixation (PRF), and anterior spinal column fixation (ACF)); however, long-term follow-up data and comparative studies of the different techniques are still missing. Soft-tissue reconstruction can be performed according to an algorithm depending on the surgical approach, but relatively high complication rates are reported with all reconstruction strategies. The clinical outcome of such surgeries should ideally be evaluated in three dimensions; surgical-, oncological-, and functional outcomes. The last and most important step of the presurgical planning procedure is a careful presentation of the surgical goals and risks to the patient, who must provide a fully informed consent before surgery can proceed.

DISCUSSION

Sacropelvic tumors are rare conditions. In the last decade, growing evidence was published on resection and reconstruction techniques for these tumors; however, experience at most medical centers is limited due to the low numbers of cases. The formation of international expert groups and the initiation of multicenter studies are strongly encouraged to produce a high level of evidence in this special field of spine surgery.

Gait-simulating fatigue loading analysis and sagittal alignment failure of spinal pelvic reconstruction after total sacrectomy: comparison of 3 techniques

OBJECT

Reconstruction after total sacrectomy is a critical component of malignant sacral tumor resection, permitting early mobilization and maintenance of spinal pelvic alignment. However, implant loosening, graft migration, and instrumentation breakage remain major problems. Traditional techniques have used interiliac femoral allograft, but more modern methods have used fibular or cage struts from the ilium to the L-5 endplate or sacral body replacement with transiliac bars anchored to cages to the L-5 endplate. This study compares the biomechanical stability under gait-simulating fatigue loading of the 3 current methods.

METHODS

Total sacrectomy was performed and reconstruction was completed using 3 different constructs in conjunction with posterior spinal screw rod instrumentation from L-3 to pelvis: interiliac femur strut allograft (FSA); L5-iliac cage struts (CSs); and S-1 body replacement expandable cage (EC). Intact lumbar specimens (L3-sacrum) were tested for flexion-extension range of motion (FE-ROM), axial rotation ROM (AX-ROM), and lateral bending ROM (LB-ROM). Each instrumented specimen was compared with its matched intact specimen to generate an ROM ratio. Fatigue testing in compression and flexion was performed using a custom-designed long fusion gait model.

RESULTS

Compared with intact specimen, the FSA FE-ROM ratio was 1.22 ± 0.60, the CS FE-ROM ratio was significantly lower (0.37 ± 0.12, p < 0.001), and EC was lower still (0.29 ± 0.14, p < 0.001; values are expressed as the mean ± SD). The difference between CS and EC in FE-ROM ratio was not significant (p = 0.83). There were no differences in AX-ROM or LB-ROM ratios (p = 0.77 and 0.44, respectively). No failures were noted on fatigue testing of any EC construct (250,000 cycles). This was significantly improved compared with FSA (856 cycles, p < 0.001) and CS (794 cycles, p < 0.001).

CONCLUSIONS

The CS and EC appear to be significantly more stable constructs compared with FSA with FE-ROM. The 3 constructs appear to be equal with AX-ROM and LB-ROM. Most importantly, EC appears to be significantly more resistant to fatigue compared with FSA and CS. Reconstruction of the load transfer mechanism to the pelvis via the L-5 endplate appears to be important in maintenance of alignment after total sacrectomy reconstruction.

Surgical techniques for spinopelvic reconstruction following total sacrectomy: a systematic review

PURPOSE

To identify all available reconstruction methods for a total sacrectomy. Secondarily, we aimed to evaluate outcomes based on different interventions.

METHODS

We searched PubMed to identify sacral resections for tumors requiring internal fixation for stabilization. Demographic information, fixation techniques and postoperative outcomes were abstracted.

RESULTS

Twenty-three publications (43 patients) met inclusion criteria from an initial search of 856 (κ 0.93). Mean age was 37 years and follow-up was 33 months. Fixation methods included a combination of spinopelvic fixation (SPF), posterior pelvic ring fixation (PPRF), and/or anterior spinal column fixation (ASCF). For the purposes of analysis, patients were segregated based on whether they received ASCF. Postoperative complications including wound/instrument infections, GI or vascular complications were reported at a higher rate in the non-ASCF group (1.63 complications/patient vs. 0.7 complications/patient). Instrument failure was seen in 5 (16.1 %) out of the 31 patients with reported outcomes. Specifically, 1 out of 8 patients (12.5 %) with ASCF compared with 4 out of 23 patients (17.4 %) without ASCF had hardware failure. At final follow-up, 35 of 39 patients were ambulating.

CONCLUSION

While surgical treatment of primary sacral tumors remains a challenge, there have been advances in reconstruction techniques following total sacrectomy. SPF has shifted from intrapelvic rod and hook constructs to pedicle and iliac screw-rod systems for improved rigidity. PPRF and ASCF have adapted for deficiencies in the posterior ring and anterior column. A trend toward a lower rate of hardware failure emerged in the group utilizing anterior spinal column support. Despite a more involved reconstruction with ASCF, surgical complications such as infection rates and blood loss were lower compared to the group without ASCF. While we cannot definitively say one system is superior to the other, based on the data gleaned from this systematic review, it is our opinion that incorporation of ASCF in reconstructing the spinopelvic junction may lead to improved outcomes. However, most importantly, we recommend that the treating surgeon operate on patients requiring a total sacrectomy based on his or her level of comfort, as these cases can be extremely challenging even among experts.

One-stage total en bloc sacrectomy: a novel technique and report of 9 cases

STUDY DESIGN

Nine patients with malignant sacral tumor underwent 1-stage total sacrectomy. The oncological and functional results are analyzed.

OBJECTIVE

To describe the surgical technique and evaluate the clinical outcome of the surgery.

SUMMARY OF BACKGROUND DATA

Very few reports specifically address total sacrectomy, and the 2-stage procedure combining the anterior and posterior approach is the most common method used for treatment.

METHODS

Between July 2007 and July 2010, 9 patients (7 males, 2 females; mean age, 33 yr; range, 13-59 yr) with malignant sacral tumor underwent 1-stage total sacrectomy the Peking University People's Hospital. The pathological diagnosis was chordoma in 3 patients, osteosarcoma in 2, chondrosarcoma in 2, malignant schwannoma in 1, and Ewing sarcoma in 1.

RESULTS

Oncological results: All 9 patients were followed-up for 11 to 35 months (mean follow-up time, 19.7 mo). Local recurrence was detected in the right ilium in the patient with Ewing sarcoma at 7 months after surgery, and locally in another patient with osteosarcoma at 3 months after surgery. The recurrent lesion in the right ilium was widely resected in the patient with Ewing sarcoma and no new lesion was found at the last follow-up, but this patient died of the lung metastases. The local recurrent lesion in the patient with osteosarcoma was treated with adjuvant chemotherapy and local radiation. Functional result: The S1 nerve root was cut bilaterally in 8 patients during surgery, resulting in the loss of foot plantar flexion. The 5 lumbar vertebrae were also resected with the sacrum in 1 patient, but the bilateral L5 nerve roots were preserved, and dorsiflexion was maintained in this patient.

CONCLUSION

Total sacrectomy can be performed successfully using a 1-stage combined anterior and posterior approach and is an important procedure for the treatment of primary malignant tumor involving the top portion of or the whole sacrum.

Posterior-Only Approach for En Bloc Sacrectomy

BACKGROUND:

En bloc resection of primary sacral tumors has a demonstrated survival benefit. Total and high sacral amputations are traditionally performed by using a staged anterior and subsequent posterior approach. However, we have found that en bloc resection and biomechanical reconstruction of the spinal column is possible from a posterior-only approach in many cases.

OBJECTIVE:

To assess our series of posterior-only sacrectomies, emphasizing postoperative complications and overall surgical and oncologic outcome.

METHODS:

Sixty-nine consecutive patients underwent sacral resections for tumor at our institution between 2004 and 2009. Medical records of all patients were reviewed, and patients were excluded if they had an intentional intralesional resection, hemipelvectomy, or a previous operation. The records of the resulting 36 consecutive patients who underwent primary posterior-only en bloc sacral resections were retrospectively reviewed.

RESULTS:

Of the posterior-only patients, all underwent midline posterior approaches for en bloc sacral resection. Sacral amputation was defined by the by sacral root preservation: total (2 cases), high (8 cases), middle (9 cases), low (12 cases), and distal (5 cases). Chordoma was the most common tumor type (30 cases), and surgical margins were marginal in 34 cases and contaminated in 2. Overall, there were 13 complications, including 9 wound infections/revisions. The extent of sacrectomy, and thus the extent of roots sacrificed, correlated with functional outcome.

CONCLUSION:

It may be possible to perform a posterior-only approach to en bloc sacral resections/reconstructions in patients with tumors that do not extend beyond the lumbosacral junction or invade the bowel requiring bowel resection and diversion.

Lumbopelvic reconstruction after combined L5 spondylectomy and total sacrectomy for en bloc resection of a malignant fibrous histiocytoma

BACKGROUND

Primary sacral neoplasms that extend superiorly to involve the distal lumbar spine represent complex surgical problems. Treatment options for these patients are often limited to hemicorporectomy.

OBJECTIVE

To detail our surgical technique for en bloc resection of a sarcoma involving the L5 vertebral segment and sacrum and the reconstruction of the lumbopelvic junction.

METHODS

A 52-year-old woman presented with intractable pain secondary to a sarcoma involving the L5 vertebral segment and sacrum. She underwent a combined L5 spondylectomy and total sacrectomy for en bloc resection of her neoplasm. A novel lumbopelvic reconstruction technique was used to establish a liaison between the lumbar spine and pelvis.

RESULTS

Operative complications included a venous vascular injury and a nonviable myocutaneous flap. Postoperatively, the patient had complete resolution of her pain. Unfortunately, the patient developed metastatic disease and died 5 months after her initial surgical procedure.

CONCLUSION

We describe a patient who underwent a combined L5 spondylectomy and total sacrectomy for en bloc resection of a lumbosacral sarcoma. Additionally, we report a novel technique to reconstruct the lumbopelvic junction. The operative procedures are detailed with the aid of radiographs, intraoperative photographs, and illustrations.

Sacral tumor resection and the impact on pelvic incidence

Object

Pelvic incidence (PI) directly regulates lumbar lordosis and is a key determinant of sagittal spinal balance in normal and diseased states. Pelvic incidence is defined as the angle between the line perpendicular to the S-1 endplate at its midpoint and the line connecting this point to a line bisecting the center of the femoral heads. It reflects an anatomical value that increases with growth during childhood but remains constant in adulthood. It is not altered by changes in patient position or after traditional lumbosacral spinal surgery. There are only 2 reports of PI being altered in adults, both in cases of sacral fractures resulting in lumbopelvic dissociation and sacroiliac (SI) joint instability. En bloc sacral amputation and sacrectomy are surgical techniques used for resection of certain bony malignancies of the sacrum. High, mid, and low sacral amputations result in preservation of some or the entire SI joint. Total sacrectomy results in complete disruption of the SI joint. The purpose of this study was to determine if PI is altered as a result of total or subtotal sacral resection.

Methods

The authors reviewed a series of 42 consecutive patients treated at The Johns Hopkins Hospital between 2004 and 2009 for sacral tumors with en bloc resection. The authors evaluated immediate pre- and postoperative images for modified pelvic incidence (mPI) using the L-5 inferior endplate, as the patients undergoing a total sacrectomy are missing the S-1 endplate postoperatively. The authors compared the results of total versus subtotal sacrectomies.

Results

Twenty-two patients had appropriate images to measure pre- and postoperative mPI; 17 patients had high, mid, or low sacral amputations with sparing of some or the entire SI joint, and 5 patients underwent a total sacrectomy, with complete SI disarticulation. The mean change in mPI was statistically different (p < 0.001) for patients undergoing subtotal versus those undergoing total sacrectomy (1.6° ± 0.9° vs 13.6° ± 4.9° [± SD]). There was no difference between patients who underwent a high sacral amputation (partial SI resection, mean 1.6°) and mid or low sacral amputation (SI completely intact, mean 1.6°).

Conclusions

The PI is altered during total sacrectomy due to complete disarticulation of the SI joint and discontinuity of the spine and pelvis, but it is not changed if any of the joint is preserved. Changes in PI influence spinopelvic balance and may have postoperative clinical importance. Thus, the authors encourage attention to spinopelvic alignment during lumbopelvic reconstruction and fixation after tumor resection. Long-term studies are needed to evaluate the impact of the change in PI on sagittal balance, pain, and ambulation after total sacrectomy.

En Bloc Resection for Primary and Metastatic Tumors of the Spine

BACKGROUND

The efficacy of en bloc resection for spinal tumors is unknown because most of the current evidence is provided by small, single-institution clinical series or case reports.

OBJECTIVE

To combine all previously published reports of en bloc resection for primary and metastatic spinal tumors, to describe the overall pattern of disease-free survival, and to investigate potentially prognostic factors for recurrence.

METHODS

A complete MEDLINE search for all articles reporting survival data for en bloc resection of spinal tumors was undertaken; 44 articles met inclusion criteria from which 306 eligible patients were identified.

RESULTS

There were 229 cases of primary tumors with a mean follow-up of 65.0 months and 77 cases of solitary metastatic tumors with a mean follow-up of 26.5 months. Median time to recurrence was 113 months for the primary group and 24 months for the metastatic group. Disease-free survival rates at 1, 5, and 10 years were 92.6%, 63.2%, and 43.9%, respectively, for the primary group and 61.8%, 37.5%, and 0%, respectively, for the metastatic group; 5-year disease-free survival rates were 58.4% for chordoma and 62.9% for chondrosarcoma. After adjusting for covariates, age, male sex, metastatic tumors, and osteosarcomas were significantly associated with a tumor recurrence.

CONCLUSION

This study provides the largest published series of patients undergoing en bloc resection for spinal tumors. Median time to recurrence reached almost 10 years in patients with primary tumors; however, it was only 2 years in those with isolated metastatic tumors.

En bloc sacrectomy and reconstruction: technique modification for pelvic fixation

BACKGROUND

When the management of sacral tumors requires partial or complete sacrectomy, the spinopelvic apparatus must be reconstructed. This is a challenging and infrequently performed operation, and as such, many spine surgeons are unfamiliar with techniques available to carry out these procedures.

CASE DESCRIPTION

A 34-year-old man presented with severe low back pain, mild left ankle dorsiflexion weakness, and left S1 paresthesias. Imaging revealed a large sacral mass extending into the L5/S1 and S1/S2 neural foramina as well as the presacral visceral and vascular structures. Needle biopsy of this mass demonstrated a low-grade chondrosarcoma. A 2-stage anterior/posterior en bloc sacrectomy with a novel modification of the Galveston L-rod pelvic ring reconstruction was carried out. Our modification takes advantage of new materials and implant technology to offer another alternative in reconstruction of the spinopelvic junction.

CONCLUSION

Understanding the anatomy and biomechanics of the spinopelvic apparatus and the lumbosacral junction, as well as having a familiarity with the various techniques available for carrying out sacrectomy and pelvic ring reconstruction, will enable the spine surgeon to effectively manage sacral tumors.

Sacrectomy for primary sacral tumors

PURPOSE

En bloc resection with adequate margins has provided a chance for cure of primary sacral tumors. However, high sacral lesions are challenging because of the complexity of the surgical approach. The aims of this study were to describe a modification in technique and to evaluate the outcomes.

METHODS

This is a study of eight sacrectomies performed at King Chulalongkorn Memorial Hospital between February 2000 and July 2007. Cadaveric dissections were carried out prior to surgery. We have modified the technique by ligation of the branches of the external iliac veins, resulting in "isolation" of the external iliac veins. Spinopelvic reconstruction was performed for total and extended total sacrectomy. Closure of the sacral defect was done with use of the Hartmann stump and the gluteus maximus flaps.

RESULTS

Two total sacrectomies, one extended total sacrectomy, and five subtotal S1 sacrectomies were performed. En bloc resection with adequate margins was achieved in all patients. The patient who underwent extended total sacrectomy and one patient who underwent total sacrectomy had nonunion requiring removal of the spinopelvic instrumentation. Five patients who underwent subtotal sacrectomy were ambulating well postoperatively, except for one who had an S1 fracture after falling. No sacral hernias were observed. None of the patients developed recurrence of the primary tumor. Mean follow-up time was four years.

CONCLUSIONS

Sacrectomy for primary sacral tumors can be safely conducted, achieving tumor-free margins and acceptable functional and long-term outcomes.

Evaluation of factors associated with postoperative infection following sacral tumor resection

Object

Resection of sacral tumors has been shown to improve survival, since the oncological prognosis is commonly correlated with the extent of local tumor control. However, extensive soft-tissue resection in close proximity to the rectum may predispose patients to wound complications and infection. To identify potential risk factors, a review of clinical outcomes for sacral tumor resections over the past 5 years at a single institution was completed, paying special attention to procedure-related complications.

Methods

Between 2002 and 2007, 46 patients with sacral tumors were treated with surgery. Demographic data, details of surgery, type of tumor, and patient characteristics associated with surgical site infections (SSIs) were collected; these data included presence of the following variables: diabetes, obesity, smoking, steroid use, previous surgery, previous radiation, cerebrospinal fluid leak, number of spinal levels exposed, instrumentation, number of surgeons scrubbed in to the procedure, serum albumin level, and combined anterior-posterior approach. Logistic regression analysis was implemented to find an association of such variables with the presence of SSI.

Results

A total of 46 patients were treated for sacral tumor resections; 20 were male (43%) and 26 were female (57%), with an average age of 46 years (range 11–83 years). Histopathological findings included the following: chordoma in 19 (41%), ependymoma in 5 (11%), rectal adenocarcinoma in 5 (11%), giant cell tumor in 4 (9%), and other in 13 (28%). There were 18 cases of wound infection (39%), and 2 cases of repeat surgery for tumor recurrence (1 chordoma and 1 giant cell tumor). Factors associated with increased likelihood of infection included previous lumbosacral surgery (p = 0.0184; odds ratio [OR] 7.955) and number of surgeons scrubbed in to the operation (p = 0.0332; OR 4.018). Increasing age (p = 0.0864; OR 1.031), presence of complex soft-tissue reconstruction (p = 0.118; OR 3.789), and bowel and bladder dysfunction (p = 0.119; OR 2.667) demonstrated a trend toward increased risk of SSI.

Conclusions

Patients undergoing sacral tumor surgery may be at greater risk for developing wound complications due to the extensive soft-tissue resections often required, especially with the increased potential for contamination from the neighboring rectum. In this study, it appears that previous lumbosacral surgery, number of surgeons scrubbed in, patient age, bowel and bladder dysfunction, and complex tissue reconstruction may predict those patients more prone to developing postoperative SSIs.

Solitary lymph node metastasis without local recurrence of primary chordoma

Chordoma is a malignant neoplasm believed to arise from notochord remnants. Its incidence is highest in the sixth decade and is generally regarded as a locally aggressive tumor with slow progression growth rate. Its metastatic incidence ranges from 5 to 40%, and it is generally believed that metastases without local recurrence of primary neoplasm are extremely rare. We report a case of a 38-year-old male patient with solitary inguinal lymph node metastasis without local recurrence of a previously surgically treated primary sacrococcygeal chordoma.

En Bloc Total Sacrectomy Performed in a Single Stage through a Posterior Approach

Objective:

Total sacrectomies are performed for extensive en bloctumor resections. Exposure traditionally combines a posterior approach with a laparotomy to facilitate vascular control. We present a case of a total en bloc sacrectomy performed entirely through the posterior approach, thereby avoiding the need for a laparotomy.

Clinical Presentation:

A 57-year-old man presented with sacral pain and loss of bowel and bladder function. A large sacral mass was identified and submitted to biopsy. Results were consistent with an osteoblastoma, although osteosarcoma could not be excluded on pathological examination. The patient was taken to the operating room for a total sacrectomy and en bloc resection of the mass.

Technique:

Lateral iliac osteotomies were performed, followed by an L5–S1 discectomy and resection of the annulus, thus mobilizing the sacrum. Gradual distraction of the interspace coupled with upward traction of the sacrum provided an anterior exposure through which the internal iliac vessels were controlled, dissected, and divided. A combined transperineal approach completed the posterior dissection and the tumor was delivered en bloc. Lumbopelvic reconstruction was performed simultaneously.

Conclusion:

With the use of interspace distraction and sacral elevation to facilitate vascular control, a total sacrectomy was performed without the need for the anterior exposure of a laparotomy.

Biomechanical testing of a novel four-rod technique for lumbo-pelvic reconstruction

STUDY DESIGN

A biomechanical testing protocol was used to study different lumbo-pelvic fixation techniques in a human cadaveric lumbar spine model.

OBJECTIVE

To compare the in vitro biomechanics of a novel four-rod lumbo-pelvic reconstruction technique with and with out cross-links, to that of a conventional cross-linked two-rod technique.

SUMMARY OF BACKGROUND DATA

Numerous lumbo-pelvic reconstruction methods based on the Galveston two-rod technique have been proposed for cases involving total sacrectomy. Recently a technique that proposes novel use of 4 supporting longitudinal rods across the lumbo-pelvic junction has been reported. No comparative in vitro biomechanical testing has been previously done to evaluate these different reconstruction methods.

METHODS

Five spines were evaluated in flexion, extension, left-right lateral bending and left-right axial rotation in a human total sacrectomy model. The model was comprised of cadaveric lumbar spines (L1-L5) with custom fabricated polyethylene blocks used to simulate pelvic fixation. Three conditions were evaluated: Linked Four-Rod, Linked Two-Rod, and Four-Rod (no cross-links). Flexibility and motion data were compared using a one-way repeated measures analysis of variance and SNK tests.

RESULTS

The Linked Four-Rod and Four-Rod conditions significantly decreased flexibility and reduced L5-Pelvic motion over the Linked Two-Rod construct in flexion and extension. The Linked Four-Rod condition significantly decreased flexibility in left-right axial rotation compared with the Four-Rod and Linked Two-Rod conditions. No significant differences occurred in relative lateral movement between left and right pelvic polyethylene blocks.

CONCLUSION

The four-rod technique improved fixation stability over the conventional linked two-rod technique in flexion and extension, and when cross-linked, in left-right axial rotation. The four-rod technique also significantly reduced L5-Pelvic junction movement in flexionand extension, which may have implications for bony fusion. The use of cross-links is recommended.