Long-term survival following total sacrectomy with reconstruction for the treatment of primary osteosarcoma of the sacrum. A case report

Novel Graft Technique for Lumbopelvic Reconstruction After Sacral Tumor Resection: A Case Report

CASE

Reconstruction after sacral tumor resection carries a high risk of nonunion and requires a slow return to weight-bearing. A bilateral iliac-crest graft, mobilized on a muscular pedicle, was used to graft and fuse the spine and pelvis after resection of a massive sacral schwannoma. Long-term follow-up and three-dimensional computed tomography imaging demonstrate rapid incorporation and solid fusion, with hypertrophy of the graft struts and excellent return to function.

CONCLUSION

This novel graft technique provides structural autograft bone that bridges the iliolumbar resection gap, providing a vascularized autograft that incorporates rapidly and reliably.

One-Step Reconstruction with a Novel Suspended, Modular, and 3D-Printed Total Sacral Implant Resection of Sacral Giant Cell Tumor with Preservation of Bilateral S1-3 Nerve Roots via a Posterior-Only Approach

Objective

To investigate the efficacy and safety of spinopelvic reconstruction based on a novel suspended, modular, and 3D‐printed total sacral implant after total piecemeal resection of a sacral giant cell tumor (SGCT) with the preservation of bilateral S_1–3 nerve roots via a posterior‐only approach.

Methods

Five patients who had undergone total piecemeal resection of SGCT involving upper sacral segments (S₁ and S₂) and the midline with the preservation of bilateral S_1–3 nerve roots via a posterior‐only approach between September 2017 and July 2018 were retrospectively reviewed. A novel suspended, modular, and 3D‐printed total sacral implant had been used for reconstruction. This series included two female and three male patients, with a mean age of 42.2 years (range, 31–53 years). Surgical time, blood loss, complications, preoperative and postoperative neurological function, instrumentation failure, and local control were presented and analyzed.

Results

All patients underwent the operation without death or serious complications. The implant was installed on the defect, connecting the ilium and lumbar vertebrae, and fixed with a screw–rod system up to the level of L_3–4 or L_4–5. The mean operative time was 502 min (range, 360–640 min) and the mean operative blood loss 4400 mL (range, 3000–7000 mL). The mean follow‐up was 15 months. After the operation, pain was significantly relieved, and the patients resumed walking as early as 2 weeks later. The patients showed no neurogenic bladder dysfunction and no fecal incontinence or gait disturbance. Wound healing was poor in one patient. Patients recovered well without evidence of local recurrence. No implant failures or related clinical symptoms were detected during follow up. Satisfactory bone ingrowth and osseointegration at the bone‐implant junctions was found in follow‐up CT.

Conclusion

Although technically challenging, it is feasible and safe to use a suspended, modular, and 3D‐printed implant for reconstruction after total piecemeal resection with the preservation of bilateral S_1–3 nerve roots in patients with SGCT. We believe that this implant can be applied to sacral reconstruction in a wide variety of diseases.

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.

Factors Associated With Spinopelvic Fixation Mechanical Failure After Total Sacrectomy

STUDY DESIGN

We retrospectively analyzed factors associated with spinopelvic mechanical failure after total sacrectomy.

OBJECTIVE

To find the rate and type of mechanical fixation failure after total sacrectomy and to identify the associated risk factors.

SUMMARY OF BACKGROUND DATA

Although rigid fixation has been achieved, mechanical failure is sometimes encountered in reconstruction after total sacrectomy. The incidence and factors associated with spinopelvic fixation mechanical failure after total sacrectomy are still not clear.

METHODS

The study comprised 63 patients who underwent spinopelvic reconstruction after total sacrectomy. The potential risk factors for fixation mechanical failure after total sacrectomy were evaluated, which included age, sex, body mass index, type of tumor (benign or malignant), and adjuvant treatment received (e.g., chemotherapy, radiation therapy). The surgery-related factors included the classification of tumor resection (en bloc or piecemeal resection) and the type of iliosacral resection. Adoption of anterior spinal column fixation (ASCF), posterior pelvic ring fixation (PPRF), four-rod technique (FRT) of spinopelvic fixation (SPF), and structural or morselized bone grafting after total sacrectomy in patients were considered reconstruction-related factors. Cox regression models were used to analyze associations between postoperative fixation failure and risk factors for all models.

RESULTS

Postoperative fixation mechanical failure occurred in 25% of patients (16/63) who underwent total sacrectomy. Univariate analysis showed that the factors associated with spinopelvic fixation mechanical failure after total sacrectomy were the non-adoption of FRT of SPF and ASCF, the adoption of Type II sacroiliac resection, and female sex, whereas multivariate analysis demonstrated similar results, except for the adoption of Type II sacroilliac resection.

CONCLUSION

FRT connection of SPF and ASCF should be adopted in reconstruction after total sacrectomy, especially in female patients.

LEVEL OF EVIDENCE

3.

Surgical Treatment of Primary Osteosarcoma of the Sacrum: A Case Series of 26 Patients

STUDY DESIGN

Twenty-six patients were treated surgically for sacral osteosarcomas in our center. The oncological and functional results are analyzed.

OBJECTIVE

To describe the general characteristics and evaluate the outcome of surgical treatment of primary osteosarcoma of the sacrum.

SUMMARY OF BACKGROUND DATA

A very few reports have addressed the technique and outcome of surgical treatment of primary sacral osteosarcoma. The survival rate of such cases is low.

METHODS

The clinical data of 26 patients treated surgically for sacral osteosarcomas from June 2000 to December 2013 at our hospital were retrospectively reviewed.

RESULTS

There were 15 males and 11 females with a median age of 28 years (range, 12-68 years). Distal metastasis occurred in 13 patients (50%), and local recurrence occurred in 10 patients (38.5%, including 6 patients with additional distal metastasis). The 1-year and 5-year survival rates were 92.3% and 38.7%, respectively. Adequate and inadequate surgical margins were obtained in 16 and 10 cases, respectively. Patients with adequate margins had a significantly lower recurrence rate (P = 0.015) and higher event-free survival rate (P = 0.04) than those with inadequate margins. However, the overall survival rate did not differ significantly between patients with adequate and inadequate margins (P = 0.22). Only seven cases showed a good response based on necrosis rate (>90%). Patients with a better response to chemotherapy had better event-free and overall survival rates.

CONCLUSION

Adequate surgical margins are achievable in most cases of sacral osteosarcomas. Adequate margins can significantly improve the recurrence rate and event-free survival rate compared with inadequate margins. However, sacrectomy is still a challenging surgical technique. Adequate margins are also difficult to obtain in sacrectomy. In addition, only a few patients had a good response to chemotherapy. These reasons lead to a low 5-year survival rate in primary sacral osteosarcoma patients.

LEVEL OF EVIDENCE

4.

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.

Biomechanical evaluation of supplemental percutaneous lumbo-sacro-iliac screws for spinopelvic fixation following total sacrectomy

STUDY DESIGN

This is a cadaveric biomechanical study evaluating the biomechanical properties of a novel spinopelvic fixation technique with percutaneous lumbo-sacro-iliac (LSI) screws in an unstable total sacrectomy model.

OBJECTIVE

To compare standard posterior dual rod spinopelvic fixation alone with dual rod fixation supplemented with LSI screw fixation.

SUMMARY OF BACKGROUND DATA

Primary or metastatic tumors of the sacrum requiring a total sacrectomy can result in spinopelvic instability if inadequate fixation is achieved. Many fixation techniques have been proposed to address this instability. However, to date, an optimal fixation technique has not been established.

MATERIALS AND METHODS

Ten fresh-frozen cadaveric spinopelvic specimens were randomized according to bone mineral density (BMD) to either posterior rod fixation (control group) or posterior rod fixation with supplemental LSI screws (LSI group). After fixation, a total sacrectomy of each specimen was performed. Specimens where then potted and axially loaded in a caudal direction. Stiffness, yield load, energy absorbed at yield load, ultimate load, and energy absorbed at ultimate load were computed. A Student t test was used for statistical analysis with significance set at P<0.05.

RESULTS

The average age and BMD were not significantly different between the control and LSI groups (age: P=0.255; BMD: P=0.810). After normalizing for BMD, there were no significant differences detected for any of the biomechanical parameters measured between the 2 fixation techniques: stiffness (P=0.857), yield load (P=0.219), energy at yield load (P=0.293), ultimate load (P=0.407), and energy at ultimate load (P=0.773). However, both fixation techniques were able to withstand physiological loads.

CONCLUSIONS

Our study did not demonstrate any biomechanical advantage for supplemental LSI screw fixation in our axial loading model. However, given the theoretical advantage of this percutaneous technique, further studies are warranted that take into account forward bending and sagittal stability.

Soft-tissue reconstruction after total en bloc sacrectomy

OBJECT

Total en bloc sacrectomy is a dramatic procedure that results in extensive sacral defects. The authors present a series of patients who underwent flap reconstruction after total sacrectomy, report clinical outcomes, and provide a treatment algorithm to guide surgical care of this unique patient population.

METHODS

After institutional review board approval, data were collected for all patients who underwent total sacrectomy between 2002 and 2012 at The Johns Hopkins Hospital. Variables included demographic data, medical history, tumor characteristics, surgical details, postoperative complications, and clinical outcomes. All subtotal sacrectomies were excluded.

RESULTS

Between 2002 and 2012, 9 patients underwent total sacrectomy with flap reconstruction. Diagnoses included chordoma (n = 5), osteoblastoma (n = 1), sarcoma (n = 2), and metastatic colon cancer (n = 1). Six patients received gluteus maximus (GM) flaps with a prosthetic rectal sling following a single-stage, posterior sacrectomy. Four required additional paraspinous muscle (PSM) or pedicled latissimus dorsi (LD) fasciocutaneous flaps. Three patients underwent multistage sacrectomy with an anterior-posterior approach, 2 of whom received pedicled vertical rectus abdominis myocutaneous (VRAM) flaps, and 1 of whom received local GM, LD, and PSM flaps. Flap complications included dehiscence (n = 4) and infection (n = 1). During the 1st year of follow-up, 2 of 9 patients (22%) were able to ambulate with an assistive device by the 1st postoperative month, and 6 of 9 (67%) were ambulatory with a walker by the 3rd postoperative month. By postoperative Month 12, 5 of 9 patients (56%)—or 5 of 5 patients not lost to follow-up (100%)—were able to able to ambulate independently.

CONCLUSIONS

The authors' experience suggests that the GM and pedicled VRAM flaps are reliable options for softtissue reconstruction of total sacrectomy defects. For posterior-only operations, GM flaps with or without a prosthetic rectal sling are generally used. For multistage operations including a laparotomy, the authors consider the pedicled VRAM flap to be the gold standard for simultaneous reconstruction of the pelvic diaphragm and obliteration of dead space.

Locomotor biomechanics after total sacrectomy: a case report

STUDY DESIGN

Biomechanical analysis of locomotion after total sacrectomy in a single patient case.

OBJECTIVE

To describe the biomechanics of locomotion after successful total sacrectomy and spinopelvic reconstruction.

SUMMARY OF BACKGROUND DATA

Total sacrectomy is a complex surgery that has significant consequences for mobility after surgery due to loss of lower lumbar and sacral innervation to the lower extremities, and the anatomic dissociation of the spine from the pelvis. There is no existing literature quantifying locomotor biomechanics after total sacrectomy.

METHODS

A 22-year-old female with a sacral osteosarcoma underwent an en bloc sacrectomy with L3 to pelvis instrumented fusion. Neuromuscular function was tested 1 year after surgery using monopolar needle electromyography. Three-dimensional motion capture and surface electromyography were used to quantify spatiotemporal characteristics of locomotion and lower extremity kinematics, kinetics, and muscle function during locomotion at 6 months and 1 year after surgery.

RESULTS

Electrodiagnostic testing suggested partial preservation and reinnervation of S1 nerve root function on the right, resulting in greater than expected activity in the hamstrings, gluteus maximus, and triceps surae postsurgically. Unexpectedly on the left, there was residual activity in the hamstrings, despite the loss of sacral innervation and the sciatic nerve. At 1 year after surgery, the patient was able to walk independently. Kinematic and kinetic impairments and compensations were most evident in the sagittal and coronal planes.

CONCLUSION

Excellent locomotor outcomes are possible after total sacrectomy.

Imaging appearances and clinical outcome following sacrectomy and ilio-lumbar reconstruction for sacral neoplasia

OBJECTIVE

Sacrectomy and ilio-lumbar reconstruction is an uncommonly performed complex surgical procedure for the treatment of sacral neoplasia. There are many challenges in the post-operative period including the potential for tumor recurrence, infection, and construct failure. We present our experience of this patient cohort and describe the complications and imaging appearances that can be encountered during the follow-up period.

MATERIALS AND METHODS

Retrospective review of our Orthopaedic Oncology database was undertaken which has been collected over a 30-year period to identify patients that had undergone sacrectomy and ilio-lumbar reconstruction. Pre and post-operative imaging including radiographs, CT, and MRI was reviewed. These were viewed by two experienced musculoskeletal radiologists with consensus opinion if there was disagreement over the imaging findings. Data regarding patient demographics, tumor type, and dimensions was collected. Serial review of radiographs, CT, and MRI was performed to assess implant position and integrity, strut graft position and union, and for the presence of recurrence within the surgical bed.

RESULTS

Five male and two female patients (mean age 36 years, age range 15-54 years) were treated with this procedure. Histological diagnoses included chordoma, chondrosarcoma, osteosarcoma, and spindle cell sarcoma. Mean maximal tumor size on pre-operative imaging was 10.7 cm (range, 6-16 cm). Post-operative follow-up ranged from 10-46 months. A total of 76 imaging studies were reviewed. Commonly identified complications included vertical rod and cross-connector fracture and screw loosening. Fibula strut graft non-union and fracture was also evident on imaging review. Two patients demonstrated disease recurrence during the follow-up period.

CONCLUSIONS

This study demonstrates the spectrum and frequency of complications that can occur following sacrectomy and ilio-lumbar reconstruction for sacral neoplasia.

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.

The strain at bone-implant interface determines the effect of spinopelvic reconstruction following total sacrectomy: a strain gauge analysis in various spinopelvic constructs

PURPOSE

There is still some controversy regarding the optimal biomechanical concept for spinopelvic stabilization following total sacrectomy for malignancy. Strains at specific anatomical sites at pelvis/sacrum and implants interfaces have been poorly investigated. Herein, we compared and analyzed the strains applied at key points at the bone-implant interface in four different spinopelvic constructs following total sacrectomy; consequently, we defined a balanced architecture for spinopelvic fusion in that situation.

METHODS

Six human cadaveric specimens, from second lumbar vertebra to proximal femur, were used to compare the partial strains at specific sites in a total sacrectomy model. Test constructs included: (1) intact pelvis (control), (2) sacral-rod reconstruction (SRR), (3) bilateral fibular flap reconstruction (BFFR), (4) four-rods reconstruction (FRR), and (5) improved compound reconstruction (ICR). Strains were measured by bonded strain gauges onto the surface of three specific sites (pubic rami, arcuate lines, and posterior spinal rods) under a 500 N axial load.

RESULTS

ICR caused lower strains at specific sites and, moreover, on stress distribution and symmetry, compared to the other three constructs. Strains at pubic rami and arcuate lines following BFFR were lower than those following SRR, but higher at the posterior spinal rod construct. The different modes of strain distribution reflected different patient's parameter-related conditions. FRR model showed the highest strains at all sites because of the lack of an anterior bracing frame.

CONCLUSIONS

The findings of this investigation suggest that both anterior bracing frame and the four-rods load dispersion provide significant load sharing. Additionally, these two constructs decrease the peak strains at bone-implant interface, thus determining the theoretical surgical technique to achieve optimal stress dispersion and balance for spinopelvic reconstruction in early postoperative period following total sacrectomy.

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.

Comparison of four reconstruction methods after total sacrectomy: a finite element study

BACKGROUND

After total sacrectomy, it is mandatory to reconstruct the continuity between the lumbar spine and the pelvis. Only few biomechanical analyses exist which compare different reconstructions. Therefore, the aim of this study was to compare the lumbo-pelvic motion and the relative risk of implant breakage for four different reconstructions after total sacrectomy.

METHOD

Finite element analyses were performed for four general different reconstructions after total sacrectomy: sacral-rod reconstruction, four-rod reconstruction, bilateral fibular flaps reconstruction, and improved compound reconstruction. The rotations between L5 vertebra and ilium, the L5 shift-down displacement, and the maximum von Mises stress in the implants were calculated and evaluated for flexion, extension, lateral bending and axial rotation.

FINDINGS

The decreasing order of the rotations between L5 vertebra and ilium as well as of the L5 shift-down displacement for the studied reconstruction methods was four-rod reconstruction>sacral-rod reconstruction>bilateral fibular flaps reconstruction>improved compound reconstruction. The decreasing order of the maximum von Mises stress in the implants was sacral-rod reconstruction>four-rod reconstruction>bilateral fibular flaps reconstruction>improved compound reconstruction.

INTERPRETATION

From the mechanical point of view, improved compound reconstruction is superior to the other methods studied here as it shows the highest stability and the lowest maximum von Mises stress. However, clinical aspects must also be regarded when choosing a reconstruction method for a specific patient.

High long-term local control with sacrectomy for primary high-grade bone sarcoma in children

BACKGROUND

Sacrectomy may offer curative potential for primary sarcomas of the sacrum. However, it is unclear whether and to what extent sacrectomies achieve local control.

QUESTIONS/PURPOSE

We therefore determined the curative potential, walking ability, continence control, and quality of life for children after sacrectomy for primary bone sarcoma.

METHODS

We retrospectively reviewed eight children with high-grade primary bone sarcomas treated with sacrectomy. The average age of the patients was 14 years (range, 4-18 years). There were six Ewing sarcomas and two osteosarcomas. Five patients underwent partial and three underwent total sacrectomies with all resection margins free of tumor. We recorded local and distant recurrences, functional (Musculoskeletal Tumor Society [MSTS] score) and oncologic outcome (survival), walking ability, bladder and bowel control, independence, and reintegration in society. The average followup was 80 months (range, 54-204 months).

RESULTS

Six patients were alive without evidence of disease at last followup. Three patients had metastases develop and two died of disease 3 and 25 months postoperative. MSTS scores among survivors averaged 17.5 points (range, 5-25 points). Seven of the eight patients were able to ambulate, two independently. All initially were incontinent, but at last followup, two were continent and two were incontinent only under stress. Complications occurred in seven of eight, five of whom required additional surgery.

CONCLUSION

Despite the high incidence of neurologic deficits and complications, sacrectomy achieved local control in patients with high-grade bone sarcomas. Our observations suggest long-term survival and adequate quality of life are possible in the pediatric population.

LEVEL OF EVIDENCE

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

Structural stability of different reconstruction techniques following total sacrectomy: a biomechanical study

BACKGROUND

The biomechanical stability of spino-pelvis structure after varying reconstruction methods following total sacrectomy remains poorly defined. The objective of this study was to compare the structural stability of different reconstruction techniques.

METHODS

Six fresh human cadavers (L2-pelvis-femora) were used to compare biomechanical stability after reconstruction using four different techniques: (1) sacral rod reconstruction; (2) bilateral fibular flap reconstruction; (3) four-rod reconstruction; and (4) improved compound reconstruction. After total sacrectomy, the construction was carried out using each method once in each cadaver. Structural stiffness was evaluated by linear and angular ranges of motion. L5 relative shift-down displacement, abduction angle on the coronal plane and rotation angle on the sagittal plane, were calculated based on displacement of the identification point under 500N axial loading. Overall stiffness was estimated using load displacement curve.

FINDINGS

Improved compound reconstruction resulted in significantly higher stiffness than all three other techniques. The structural stability following bilateral fibular flap reconstruction was superior to that after sacral rod reconstruction. Four-rod reconstruction achieved worst stability due to the lack of anterior bracing applied in three other methods.

INTERPRETATION

Improved compound reconstruction produces optimal structural stability after total sacrectomy. This finding suggests that both anterior bracing and alternation of screw trajectory are important in achieving optimal structural stability.

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.

Diagnosis and management of sacral tumors

Sacral tumors pose significant challenges to the managing physician from diagnostic and therapeutic perspectives. Although these tumors are often diagnosed at an advanced stage, patients may benefit from good clinical outcomes if an aggressive multidisciplinary approach is used. In this review, the epidemiology, clinical presentation, imaging characteristics, treatment options, and published outcomes are discussed. Special attention is given to the specific anatomical constraints that make tumors in this region of the spine more difficult to effectively manage than those in the mobile portions of the spine.

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.

A novel "four-rod technique" for lumbo-pelvic reconstruction: theory and technical considerations

STUDY DESIGN

Surgical technique with case example.

OBJECTIVE

To report on a novel technique that allows for the placement of 4 separate longitudinal rods across the lumbo-pelvic junction.

SUMMARY OF BACKGROUND DATA

Despite advances in surgical techniques and instrumentation, lumbo-pelvic fixation remains a significant challenge. Fusions to the pelvis create long lever arms and generate high forces across the lumbosacral junction, resulting in high rates of screw pullout and implant fracture. In the attempt to achieve better bony fixation, techniques described include the use of bone cement, hydroxyapatite, and expandable screws. Although this process has decreased the incidence of screw pullout, it has not addressed the problem of rod fracture at the lumbo-pelvic junction.

METHOD

There are 4 separate longitudinal rods placed across the lumbo-pelvic junction that couples proximal lumbar screw anchors to 4 separate pelvic fixation points. Proximal lumbar fixation anchors are based on alternating Roy-Camille "straight ahead" screws and Magerl "lateral to medial converging" pedicle screws. There are 4 distal pelvic fixation anchors used based on 1 pair of Galveston-like screws and 1 pair of proximal iliac wing screws.

RESULTS

Early results of both ex vivo and in vivo reconstruction show that careful insertion of the lumbar and pelvic screws allows for divergent placement of the pedicle screw heads in a manner that 2 longitudinal rods can be placed per side, resulting in a total of 4 longitudinal rods across the lumbo-pelvic junction. Selection of cross-links in various combinations allows for additional axial and torsional stability, depending on the desired reconstruction.

CONCLUSION

Longer follow-up is necessary, and biomechanical and finite element studies are needed to show long-term efficacy of this technique, however, early results indicate that such a construct is feasible. Furthermore, depending on the general medical condition of the patient, immediate postoperative weight bearing is possible and reasonable.

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

Although radical resection prolongs the disease-free survival period, surgical management of primary sacral tumors is challenging because of their location and often large size. Moreover, in cases of lesions for which a radical resection necessitates total sacrectomy, reconstruction is required. The authors have previously described a modified Galveston technique in which a liaison between the spine and pelvis is achieved using lumbar pedicle screws and Galveston rods embedded into the ilia; additionally, a transiliac bar reestablishes the pelvic ring. Although this reconstruction technique achieves stabilization, several biomechanical limitations exist. In the present report the authors present the case of a patient who underwent spinal pelvic reconstruction after a total sacrectomy was performed to remove a giant sacral chordoma. They describe a novel spinal pelvic reconstruction technique that addresses some of the biomechanical limitations.

Level-adjusted perioperative risk of sacral amputations

BACKGROUND AND OBJECTIVES

Sacral amputations above the S2 body often involve increased surgical complexity leading to long-term morbidity. The purpose of this study was to determine whether proximal sacral amputations have substantially higher perioperative morbidity compared with more distal sacral amputations.

METHODS

We evaluated the effect of sacral amputation level on perioperative outcomes within 90 days of surgery. Outcome measures included blood loss, intensive care unit (ICU) and hospital stay, hospital cost, and incidence of a major and minor morbidity. Survival analyses were adjusted for the level of resection and histological appearance.

RESULTS

Thirteen proximal and 14 distal resections were performed. In comparing proximal versus distal resections, median estimated blood loss was 4 L versus 1 L (P < 0.001), ICU stay was 4 days versus 0 days (P = 0.012), hospital stay was 19 days versus 8 days (P = 0.001), hospital cost was 28,800 dollars versus 7,500 dollars (P = 0.003), with one or more major complications in 85% versus 29% (P = 0.011). Survival analysis demonstrated that the sacral resection level did not influence survival (P = 0.936), whereas the type of tumor did influence survival (P = 0.012).

CONCLUSION

Tumor resections above S2 demonstrate increased perioperative morbidity, suggesting that proximal osteotomies be reserved for patients with a realistic cure potential.

Osteogenic sarcoma of the sacral spine: an interdisciplinary team challenge

A child with osteogenic sarcoma of the sacral spine has complex nursing and interdisciplinary team needs. The course of one patient is discussed, both from the patient and family's perspective and that of her inter-disciplinary care team. The need for a coordinated, holistic approach to care that involves advance planning, continual reassessment of goals, and clear communication among the team members and consulting services is clearly demonstrated.

Osteosarcoma of the pelvis in children and young adults: the St. Jude Children's Research Hospital experience

BACKGROUND

Pelvic osteosarcomas are difficult to resect. The authors reviewed their institution's experience with patients who had such tumors to characterize the patients' clinical findings and to assess the impact of surgical resection on outcome.

METHODS

A review was conducted of the records from patients with pelvic osteosarcoma who were treated at the authors' institution between January, 1970 and March, 2004.

RESULTS

Among 442 patients with osteosarcoma, 19 patients (4%) had high-grade tumors arising in the pelvic bones, including the ilium in 15 patients, the pubis in 2 patients, and the sacrum in 2 patients. The median patient age at diagnosis was 16.8 years. Four tumors were secondary to radiation therapy. Five patients had metastases in the lung (n = 4 patients) or bone (n = 1 patient) at diagnosis. Ten tumors were chondroblastic. The median greatest tumor dimension for the 13 tumors with known size was 10 cm. Ten patients had unresectable pelvic tumors, and 9 patients underwent hemipelvectomy (2 internal and 7 external); complete resection with negative margins was achieved in 5 patients. Four patients survived, including one patient who survived with disease. Of the three patients who survived disease-free, one patient underwent complete resection, one patient underwent incomplete resection (nonviable tumor at the soft tissue margin) with a good response to chemotherapy, and one patient with a sacral tumor underwent radiotherapy only for local control. Of the 9 patients who underwent resection, 7 experienced disease recurrence (n = 5 patients) or progression (n = 2 patients) at distant sites and died. All patients with metastatic disease at diagnosis died.

CONCLUSIONS

Pelvic osteosarcomas often were large and unresectable. A high propensity for metastasis contributed to the poor outcome of patients with pelvic osteosarcoma. New therapeutic approaches are needed.

Extended total sacrectomy and reconstruction for sacral tumor

STUDY DESIGN

This case report includes the results of long-term follow-up after extended total sacrectomy in a 13-year-old boy with a sarcoma originating in the sacrum with an extraskeletal extension and infiltration into the left ilium.

OBJECTIVE

To report and discuss a case of sacral tumor treated by extended sacrectomy.

SUMMARY OF BACKGROUND DATA

Sacral tumors are often at an advanced stage with a large volume at diagnosis. Although total or extended sacrectomy is the only radical means to treat the massive sacral tumor, unavoidable complications in total sacrectomy are serious in the treatment selection.

METHODS

Initial histologic findings indicated a synovial sarcoma. Additional genetic analysis redesignated the tumor as an unclassified sarcoma. Preoperative neoadjuvant chemotherapy and radiotherapy were completed. The response to the preoperative treatment appeared as a reduction in tumor size (approximately 50%) on radiographs. After extended sacrectomy, the L5 vertebral body was fixed between the ilia, and the pelvic ring was compressed by the Zielke system. The ISOLA instrumentation system connected the lumbar spine and both ilia. All sacral nerve roots and the L5 root on the left side were cut.

RESULTS

At the 5-year follow-up examination, the patient was disease-free, could walk with crutches, and could climb stairs using the handrail and one crutch.

CONCLUSIONS

The patient's excellent response to preoperative antitumor treatment was considered crucial to the long-term outcome. But the decision between a radical resection with reconstruction and a less extensive procedure with combined therapy remains controversial.

Total sacrectomy and reconstruction for sacral tumors

STUDY DESIGN

Report of three patients in whom the lumbosacral junctions were successfully restored by spinal instrumentations after total sacrectomies.

OBJECTIVES

To describe the surgical technique of the reconstruction of the continuity between the pelvic ring and spinal column by using a transpedicular and iliac screw system.

SUMMARY OF BACKGROUND DATA

Although there have been case reports about reconstruction methods after total sacrectomy, biomechanical, and technical problems still remain unresolved.

METHODS

Total sacrectomy was carried out in three cases: two with chordomas and one with a recurrent giant cell tumor. In the first case, reconstruction was achieved with Zielke transpedicular screw and rod system and a sacral rod. The other two patients were reconstructed using a transpedicular and iliac screw system and a sacral rod for bilateral fixation of the iliac wings. In the third patient, the vertical rods were connected to transverse rod with rod connectors.

RESULTS

No instrumentation failure was observed, and the continuity between the pelvic wing and spinal column was established with the instrumentation and bone grafting. Although one patient died of metastatic chordoma, the lumbosacral junction was successfully reconstructed with the instrumentation. The other two patients could stand with double crutches 13 and 2 years after surgery, respectively.

CONCLUSIONS

Total sacrectomy is a feasible operation for primary malignant tumors involving the entire sacrum. Reconstruction of the union between the lumbar spine and the ilia with spinal instrumentation achieves stabilization suitable for ambulation.

Bowel and bladder function after major sacral resection

Major sacral resection generally is reserved for patients with malignant lesions. Because of the uncommon nature of these diseases, little is known about outcomes of surgical treatment. The current authors describe the retrospective analysis of bowel and bladder function in patients having major sacral resection at their institution during a 10-year period. Fifty-three patients were identified. In patients who had unilateral sacrectomy, in whom the contralateral sacral nerves were preserved, normal bowel and bladder function was retained in 87% and 89%, respectively. In patients who had bilateral S2-S5 nerve roots sacrificed, all had abnormal bowel and bladder function. In patients who had bilateral S3-S5 resection, normal bowel and bladder function was retained in 40% and 25%, respectively. In patients who had bilateral S4-S5 resection, with preservation of the S3 nerves bilaterally, normal bowel and bladder function was retained in 100% and 69%, respectively. In patients who had asymmetric sacral resections, with preservation of at least one S3 nerve root, normal bowel and bladder function was retained in 67% and 60%, respectively. These results show that unilateral resection of sacral roots or preservation of at least one S3 root in bilateral resection preserves bowel and bladder function in the majority of patients.

Improving function after total sacrectomy by using a lumbar-sacral corset

Total sacrectomy is a rarely used procedure to treat large sacral tumors, and postoperative rehabilitation has not been described in detail in the literature. The following case report describes the rehabilitation of a patient with a large sacral chordoma who underwent multistage surgery, including total sacrectomy. The use of a lumbar-sacral corset allowed earlier functional recovery and contributed greatly to successful pain management.

Reconstruction after total en bloc sacrectomy for osteosarcoma using a custom-made prosthesis: a technical note

STUDY DESIGN

A report of an innovative technique to restore the lumbosacral junction after resection of primary highly malignant osteosarcoma of the sacrum involving the whole sacrum, soft tissues, and adjacent posterior parts of both iliac wings.

OBJECTIVES

To describe the planning and design of a custom-made sacral prosthesis, the surgical technique, and clinical and functional outcome of the patient.

SUMMARY OF BACKGROUND DATA

Although there have been case reports about reconstruction methods after total sacrectomy, to date, there has not been a reported clinical case of successful reconstruction using an individual designed prosthesis based on a three-dimensional real-sized model.

METHODS

A 42-year-old woman was referred with progressive neurologic impairment due to primary osteosarcoma of the sacrum invading surrounding structures. Based on a three-dimensional real-sized model, a detailed surgical plan was developed to assure safe, wide surgical margins. In addition, the model enabled design and testing of a custom-made sacral prosthesis, to provide stable lumbosacral reconstruction.

RESULTS

After induction chemotherapy, a staged anteroposterior resection-reconstruction was successfully performed. After surgery, a superficial wound dehiscence was promptly treated. Within 3 weeks after surgery, mobilization began, and the adjuvant chemotherapy was continued. At the 36-month follow-up, the patient was disease free, had a stable, painless spinopelvic junction, and could walk short distances using ankle orthoses and crutches. Radiographs show complete incorporation of the pelvic grafts and unchanged position of the implant.

CONCLUSIONS

In planning and performing a total sacrectomy, including substantial parts of iliac wings, a three-dimensional real-sized model offers surgeons distinct advantages. Wide bony resection margins can be drawn on the model, and an individual custom-made prosthesis to re-establish spinopelvic continuity can be designed and tested before the intervention.