Pelvic Bone Tumors Research Articles

Pelvic reconstruction with different rod-screw systems following Enneking type I/I + IV resection: a clinical study.

The mechanical outcomes of patients with pelvic bone tumors involving zone I or zone I + IV who received resection and different reconstructions are not clear. Therefore, the purpose of this study was to compare the outcomes of different rod-screw systems in reconstruction for these patients, and evaluate the relative risk of mechanical failure for them. We reviewed 30 patients for a mean duration of 40.4 months of follow-up (range, 13.1–162.2 months), five patients had mechanical complications. The mechanical survival rate of two-rod and four-screw (TRFS) group was significantly higher than one-rod and two-screw (ORTS) group (p = 0.000). The implant survival rate was correlated with ages (p = 0.010), younger people are more likely to fail. Thus, TRFS fixation for pelvic reconstruction after Enneking type I/I + IV resection can provide better short to long-term mechanical stability compared with ORTS fixation, the strength of ORTS fixation is not enough. In addition, biological reconstruction such as autologous bone graft is recommended for the patients who are younger or suffered from benign tumor. As for the patients who are older, with malignant tumors, underwent adjuvant radiotherapy or chemotherapy, functional reconstruction with bone cement is a good choice.

Palliative treatment of pelvic bone tumors using radioiodine (125I) brachytherapy.

BackgroundComplete resection of pelvic bone tumors, especially recurrent and metastatic ones, is often impossible to achieve using conventional surgery. This study aimed to assess the benefits and adverse effects of computed tomography (CT)-guided radioiodine (125I) brachytherapy for inoperable recurrent and metastatic bone tumors of the pelvis.MethodsThis was a retrospective study of 22 patients with confirmed pelvic bone tumors (10 females and 12 males; 15–84 years; 21 with primary pelvic tumor and one with pelvic metastasis). CT-guided 125I brachytherapy was performed using 9–21 125I seeds (radioactivity of 0.5–0.7 mCi). Seed implantation was validated by postoperative CT scanning. Complications, pain, survival, and CT-estimated tumor size were carried out to evaluate the therapeutic benefits.ResultsPostoperative CT scans revealed satisfactory 125I seed implantation, and the radiation dose delivered to 90% of the target area (D90) was higher than the prescription dose (PD). No obvious complications were observed. Pain was reported by 19 of 22 patients, but 17 reported pain relief after implantation. Follow-up ranged 8–27 (median, 19) months. Tumor size was reduced in 11 patients within 1 month after surgery, nine patients showed no change, and tumor size increased in two patients. Finally, 1- and 2-year survival was 81.8 and 45.5%, respectively; 1- and 2-year local tumor control rates were 59.1 and 36.4%, respectively.Conclusions 125I seed implantation significantly reduced bone tumor size and relieved pain, with a low complication rate. These findings suggest that 125I brachytherapy treatment could be a useful palliative approach for pelvic bone tumor treatment.

Osteosarcoma of pelvic bones: imaging features

The metaphyseal locations of tubular bones with osteoid mineralization in young patients are important diagnostic radiologic features of osteosarcoma. The pelvic bones are an unusual location of osteosarcoma. Although osteosarcoma occurring in pelvic bones is not common, the osteoid matrix may be a critical finding for differentiating osteosarcoma from other common pelvic bone tumors. Therefore, the possibility of osteosarcoma in pelvic bones may be considered in the presence of osteoid matrix even in the old age group.

CORR Insights®: Hypotensive Epidural Anesthesia Reduces Blood Loss in Pelvic and Sacral Bone Tumor Resections.

CORR Insights®: Hypotensive Epidural Anesthesia Reduces Blood Loss in Pelvic and Sacral Bone Tumor Resections.

Hypotensive Epidural Anesthesia Reduces Blood Loss in Pelvic and Sacral Bone Tumor Resections

Resection of pelvic and sacral tumors can cause severe blood loss, complications, and even postoperative death. Hypotensive epidural anesthesia has been used to mitigate blood loss after elective arthroplasty, but to our knowledge, it has not been studied as an approach that might make resection of pelvic and sacral tumors safer. The purposes of this study were (1) to compare the blood loss and blood product use for patients undergoing pelvic and sacral tumor surgery under standard anesthesia or hypotensive epidural anesthesia; (2) to assess the frequency of end-organ damage with the two techniques; and (3) to compare 90-day mortality between the two techniques. Between 2000 and 2014, 285 major pelvic and sacral resections were performed at one center. A total of 174 (61%) had complete data sets for analysis of blood loss, transfusion use, complications, and mortality at 90 days. Of those, 102 (59%) underwent hypotensive epidural anesthesia, whereas the remainder received standard anesthetic care. The anesthetic approach was determined by the anesthetists in charge of the case with hypotensive epidural anesthesia exclusively performed by one of two subspecialty trained anesthetists as their routine for major pelvic or sacral surgery. The groups were comparable in terms of potential confounding variables such as age, gender, tumor volume, and operation performed. Hypotensive epidural anesthesia was defined as a technique using an extensive epidural block up to T2-3 dermatome, peripherally administered low-concentration intravenous adrenaline infusion, and using unimpeded spontaneous respiration to achieve controlled hypotension, precise rate control of the heart, and enhanced velocity of venous return, all aggregated thus to minimize blood loss during pelvic surgery while preserving vital perfusion. The groups were assessed for perioperative blood loss calculated from pre- and postsurgery hemoglobin and transfusion use as well as postoperative complications, morbidity, and mortality at 90 days. There was less mean blood loss in the hypotensive epidural anesthesia group (1457 mL, SD 1721, 95% confidence interval [CI], 1114-1801 versus 2421 mL, SD 2297, 95% CI, 1877-2965; p = 0.003). Patients in the hypotensive epidural anesthesia group on average received fewer packed red cell transfusions (2.7 units, SD 2.9, 95% CI, 2.1-3.2 versus 3.9 units, SD 4.4, 95% CI, 2.9-5.0; p = 0.03). There were no differences in the proportions of patients experiencing end-organ injury (7%, n = seven of 102 versus 6%, n = four of 72; p = 0.72). With the numbers available, there was no difference in 90-day mortality rate between groups (1.9%, n = two of 102 versus 1.3%, n = one of 72; p = 0.77). We found that hypotensive epidural anesthesia resulted in less blood loss, fewer transfusions, and no apparent increase in serious complications in pelvic and sacral tumor surgery performed in the setting of a high-volume tertiary sarcoma referral hospital. We recommend that further collaborative studies be undertaken to confirm our results with hypotensive epidural anesthesia in surgery for pelvic tumors. Level III, therapeutic study.

Pelvic ring reconstruction with a double-barreled free vascularized fibula graft after resection of malignant pelvic bone tumor

IntroductionIn patients undergoing limb-salvage internal hemipelvectomy, pelvic ring reconstruction is mandatory to maintain the stability of the pelvis and the spinal column, which finally expected to achieve a good functional outcome. However, no optimal reconstruction method has been established. In addition, no previous reports have highlighted the long-term complications of pelvic ring reconstruction after internal hemipelvectomy. We aimed to analyze the outcome of pelvic ring reconstruction using a double-barreled free vascularized fibula graft (VFG) after internal hemipelvectomy with special reference to long-term complications.Materials and methodsWe conducted a retrospective review of 9 consecutive patients (5 male, 4 female; mean age 31 years) who underwent pelvic ring reconstruction using a double-barreled free VFG after internal hemipelvectomy (P1, n = 4; P1 + 4, n = 3; P1 + 2, n = 2) at our institution between 1998 and 2013. The mean follow-up period was 55 months (range 3–131 months).ResultsThe mean length of the bone defect was 9 cm. The methods of fixation included a Cotrel-Dubosset rod (n = 4), screw (n = 3), and screw and plate (n = 2). Bone union was achieved in 5 of 8 patients (63 %) over a 1-year follow-up. The mean period required for bone union was 5.4 months (range 3–7 months). There were 3 early postoperative complications: 2 deep infections resulting in graft removal and 1 implant failure resulting in non-union. Among 3 patients, 2 developed scoliosis within 5 years. One patient developed lumbar disc hernia as a result of scoliosis, for which surgical intervention was required. The mean Musculoskeletal Tumor Society score was 57 % at the last follow-up.ConclusionsIn conclusion, this reconstruction method can achieve an early and high rate of bone union and provide good functional outcome. However, follow-up with careful attention to postoperative complications, including deep infection in the early postoperative period and spinal deformity in the long term, is necessary.

Resection and reconstruction of pelvic bone tumors.

The objective of this study was to assess outcome and recurrence rate after limb-salvage surgery with reconstruction for pelvic bone tumors and analyze complications and their relationship with surgery. The authors analyzed 129 patients followed for a mean of 6 years (range, 2-19 years). Chondrosarcoma was the most frequent histotype. Thirty-one cases with no acetabular involvement were reconstructed with allograft only. Acetabular resections were reconstructed with allograft prosthetic composite (n=60), allograft only (n=11), trabecular metal components (n=2), prosthesis only (n=10), saddle prosthesis (n=11), and iliofemoral arthrodesis (n=1). Margins were wide (n=94), wide contaminated (n=22), marginal (n=7), and intralesional (n=6). Oncologic outcomes were as follows: 75 patients were continuously disease free, 6 were disease free after treatment of relapse, 13 were alive with disease, 28 were dead of disease, and 5 were dead of other causes. Survival was 66% at 10 years. Local recurrence rate of malignant tumors was 22.1% and was not statistically influenced by margins (P=.140) or site (P=.933). Metastasis rate was 32.8%. Deep infection was observed in 30 (23.6%) cases, with no statistical difference between reconstructions with and without allograft (P=.09). Final external hemipelvectomy was performed in 16 cases. Newer techniques of reconstruction using stemmed acetabular cups or porous metal components combined with allograft are now available. Local control and satisfactory survival is achievable long term in patients with pelvic tumors, but this surgery implies a high rate of complications. Infection is a major complication, not influenced by the use of allografts. Amputation is rarely needed.

Navigated pelvic osteotomy and tumor resection: a study assessing the accuracy and reproducibility of resection planes in Sawbones and cadavers.

This Sawbones and cadaver study was performed to assess the accuracy and reproducibility of pelvic bone cuts made with use of a novel navigation system with a navigated osteotome and oscillating saw. Using a novel navigation system and a three-dimensional planning tool, we navigated pelvic bone cuts that were representative of typical cuts made in pelvic tumor resections. The system includes a prototype mobile C-arm for intraoperative cone-beam computed tomography, real-time optical tracking (Polaris), and three-dimensional visualization software. Three-dimensional virtual radiographs were utilized in addition to triplanar (axial, sagittal, and coronal) navigation. In part one of the study, we navigated twenty-four sacral bone cuts in Sawbones models and validated our results in sixteen similar cuts in cadavers. In part two, we developed three Sawbones models of pelvic tumors based on actual patient scenarios and compared three navigated resections with three non-navigated resections for each tumor model. Part three assessed the accuracy of the system with multiple users. There were ninety navigated cuts in Sawbones that were compared with fifty-four non-navigated cuts. In the navigated Sawbones cuts, the mean entry and exit cuts were 1.4 ± 1 mm and 1.9 ± 1.2 mm from the planned cuts, respectively. In comparison, the entry and exit cuts in Sawbones that were not navigated were 2.8 ± 4.9 mm and 3.5 ± 4.6 mm away from the planned osteotomy site. The navigated cuts were significantly more accurate (p ≤ 0.01). In the cadaver study, navigated entry and exit cuts were 1.5 ± 0.9 mm and 2.1 ± 1.5 mm from the planned cuts. The variation among three different users was 1 mm on both the entry and exit cuts. Navigation to guide pelvic bone cuts is accurate and feasible. Three-dimensional radiographs should be used for improved accuracy. Navigated cuts were significantly more accurate than non-navigated cuts were. A margin of 5 mm between the target tumor volume and the planned cut plane would result in a negative margin resection in more than 95% of the cuts. The accuracy of pelvic bone tumor resections and pelvic osteotomies can be improved with navigation to within 5 mm of the planned cut.

Computer-Assisted Planning and Patient-Specific Instruments for Bone Tumor Resection within the Pelvis: A Series of 11 Patients.

Pelvic bone tumor resection is challenging due to complex geometry, limited visibility, and restricted workspace. Accurate resection including a safe margin is required to decrease the risk of local recurrence. This clinical study reports 11 cases of pelvic bone tumor resected by using patient-specific instruments. Magnetic resonance imaging was used to delineate the tumor and computerized tomography to localize it in 3D. Resection planning consisted in desired cutting planes around the tumor including a safe margin. The instruments were designed to fit into unique position on the bony structure and to indicate the desired resection planes. Intraoperatively, instruments were positioned freehand by the surgeon and bone cutting was performed with an oscillating saw. Histopathological analysis of resected specimens showed tumor-free bone resection margins for all cases. Available postoperative computed tomography was registered to preoperative computed tomography to measure location accuracy (minimal distance between an achieved and desired cut planes) and errors on safe margin (minimal distance between the achieved cut planes and the tumor boundary). The location accuracy averaged 2.5 mm. Errors in safe margin averaged −0.8 mm. Instruments described in this study may improve bone tumor surgery within the pelvis by providing good cutting accuracy and clinically acceptable margins.

Infection After Surgical Resection for Pelvic Bone Tumors: An Analysis of 270 Patients From One Institution

Surgical treatment of pelvic tumors with or without acetabular involvement is challenging. Primary goals of surgery include local control and maintenance of good quality of life, but the procedures are marked by significant perioperative morbidity and complications. We wished to (1) evaluate the frequency of infection after limb salvage surgical resection for bone tumors in the pelvis; (2) determine whether infection after these resections is associated with particular risk factors, including pelvic reconstruction, radiotherapy or chemotherapy, type of resection, and age; and (3) analyze treatment of these infections, particularly with respect to the need of additional surgery or hemipelvectomy. From 1975 to 2010, 270 patients with pelvic bone tumors (149 with chondrosarcoma, 40 with Ewing's sarcoma, 27 with osteosarcoma, 18 with other primary malignant tumors, 11 with metastatic tumors, and 25 with primary benign tumors) were treated by surgical resection. Minimum followup was 1.1 years (mean, 8 years; range, 1-33 years). The resection involved the periacetabular area in 166 patients. In 137 patients reconstruction was performed; in 133 there was no reconstruction. Chart review ascertained the frequency of deep infections, how they were treated, and the frequency of resection arthroplasty or hemipelvectomies that occurred thereafter. A total of 55 patients (20%) had a deep infection develop at a mean followup of 8 months. There were 20 infections in 133 patients without reconstruction (15%) and 35 infections in 137 patients with reconstruction (26 %). Survivorship rates of the index procedures using infection as the end point were 87%, 83%, and 80% at 1 month, 1 year, and 5 years, respectively. Infection was more common in patients who underwent pelvic reconstruction after resection (univariate analysis, p = 0.0326; multivariate analysis, p = 0.0418; odds ratio, 1.7718; 95% CI, 1.0243-3.0650); no other risk factors we evaluated were associated with an increased likelihood of infection. Despite surgical débridements and antibiotics, 16 patients (46%) had the implant removed and five (9%) underwent external hemipelvectomy (four owing to infection and one as a result of persistent infection and local recurrence). Infection is a common complication of pelvic resection for bone tumors. Reconstruction after resection is associated with an increased risk of infection compared with resection alone, without significant difference in percentage between allograft and metallic prosthesis. When infection occurs, it requires removal of the implant in nearly half of the patients who have this complication develop, and external hemipelvectomy sometimes is needed to eradicate the infection.

Improved Accuracy with 3D Planning and Patient-Specific Instruments During Simulated Pelvic Bone Tumor Surgery

In orthopaedic surgery, resection of pelvic bone tumors can be inaccurate due to complex geometry, limited visibility and restricted working space of the pelvis. The present study investigated accuracy of patient-specific instrumentation (PSI) for bone-cutting during simulated tumor surgery within the pelvis. A synthetic pelvic bone model was imaged using a CT-scanner. The set of images was reconstructed in 3D and resection of a simulated periacetabular tumor was defined with four target planes (ischium, pubis, anterior ilium, and posterior ilium) with a 10-mm desired safe margin. Patient-specific instruments for bone-cutting were designed and manufactured using rapid-prototyping technology. Twenty-four surgeons (10 senior and 14 junior) were asked to perform tumor resection. After cutting, ISO1101 location and flatness parameters, achieved surgical margins and the time were measured. With PSI, the location accuracy of the cut planes with respect to the target planes averaged 1 and 1.2 mm in the anterior and posterior ilium, 2 mm in the pubis and 3.7 mm in the ischium (p < 0.0001). Results in terms of the location of the cut planes and the achieved surgical margins did not reveal any significant difference between senior and junior surgeons (p = 0.2214 and 0.8449, respectively). The maximum differences between the achieved margins and the 10-mm desired safe margin were found in the pubis (3.1 and 5.1 mm for senior and junior surgeons respectively). Of the 24 simulated resection, there was no intralesional tumor cutting. This study demonstrates that using PSI technology during simulated bone cuts of the pelvis can provide good cutting accuracy. Compared to a previous report on computer assistance for pelvic bone cutting, PSI technology clearly demonstrates an equivalent value-added for bone cutting accuracy than navigation technology. When in vivo validated, PSI technology may improve pelvic bone tumor surgery by providing clinically acceptable margins.

Biological Reconstruction Following the Resection of Malignant Bone Tumors of the Pelvis

Background. Surgical treatment of malignant pelvic bone tumors can be very challenging. The objective of this retrospective study was to evaluate the oncological as well as the clinical and functional outcome after limb salvage surgery and biological reconstruction. Methods. The files of 27 patients with malignant pelvic bone tumors, who underwent surgical resection at our department between 2000 and 2011, were retrospectively analyzed (9 Ewing's sarcoma, 8 chondrosarcoma, 4 osteosarcoma, 1 synovial sarcoma, 1 malignant fibrous histiocytoma, and 4 carcinoma metastases). Results. After internal hemipelvectomy reconstruction was performed by hip transposition (n = 16), using autologous nonvascularised fibular graft (n = 5) or autologous iliac crest bone graft (n = 2). In one patient a proximal femor prothetis and in three patients a total hip prosthesis was implanted at the time of resection. The median follow-up was 33 months. Two- and five-year disease-specific survival rates of all patients were 86.1% and 57.7%, respectively. The mean functional MSTS score was 16.5 (~55%) for all patients. Conclusion. On the basis of the oncological as well as the clinical and functional outcome, biological reconstruction after internal hemipelvectomy seems to be a reliable technique for treating patients with a malignant pelvic bone tumor.

Computer-Navigated Bone Cutting in the Resection of a Pelvic Bone Tumor and Reconstruction with a Massive Bone Allograft.

We present here a surgical technique using a navigation system and an oscillating saw for the resection of a pelvic bone tumor combined with an allograft reconstruction. The surgeon and radiologist together delineate the tumor on each magnetic resonance imaging (MRI) slice; then the surgeon defines target planes for tumor resection and transfers them to the allograft. With the patient in the lateral decubitus position, combine ilioinguinal with iliocrural and obturator surgical approaches to expose the ilium. Perform the osteotomies using the navigation system to guide the saw blade, following predefined target planes; perform a biopsy. Perform the osteotomies using the navigating saw, following the same target planes as used for the tumor resection. Fix the graft and cement a femoral stem in place; then reinsert all detached tendons and elevated muscles. Editor's note: This technique is based on preliminary work that has not been presented in a peer-reviewed case series publication. IndicationsContraindicationsPitfalls & Challenges.

Surgical treatment in patients with pelvic ring tumors

The results of treatment were analyzed in 34 patients with pelvic bone tumors. Extensive surgical treatment was performed as interiliac-abdominal exarticulation or amputation in 9 (26%) patients; pelvic bone-preserving surgery was made in 25 (74%) patients. Resections of the anterior or posterior pelvic semiring were carried out in 7 (28%) and 18 (72%) patients, respectively. Disease progression was diagnosed in 10 (29%) patients; 6 patients died at 6 to 16 months; 28 (82%) were alive with no signs of progression of the underlying disease at 4 to 46 months. Overall, the functional outcome of surgical treatment was rated as excellent in 17 (50%) patients, good in 8 (24%), and satisfactory in 4 (12%). Nine (26%) patients had a poor anatomic and functional status. Postoperative complications were diagnosed in 9 (26%) patients.

Hemipelvektomie: Worauf kommt es an?

Bei primär malignen Knochentumoren des Beckens ist die Hemipelvektomie oft das chirurgische Vorgehen der Wahl neben Polychemotherapie und Radiatio (bei Ewing-Sarkomen). Die Hemipelvektomie ist entweder intern (extremitätenerhaltend) oder extern möglich. Die externe Hemipelvektomie ist zumeist bei Tumorbefall von Glutealmuskulatur oder bei einer großen intrapelvinen Tumorkomponente indiziert. Inoperabilität besteht zumeist nur bei Mittellinienüberschreitung des Sakrums und Multifokalität. Eine komplette Sakrektomie ist möglich, aber äußerst mutilierend. Die Hemipelvektomie ist ein komplikationsreicher Eingriff, der aber oftmals die einzige kurative Möglichkeit für den Patienten darstellt. Postoperative Funktionsdefizite sind unumgänglich und müssen präoperativ individuell besprochen werden. Die Patienten sind aber zumeist trotz Funktionsdefizit zufrieden.

Surgical management of pelvic primary bone tumors involving the sacroiliac joint

Pelvic primary malignant bone tumours, especially when involving the sacroiliac joint are difficult to treat. Abdominoperineal amputations are today used, only in life-threatening situations. A precisely planed surgical technique can save the affected extremity without compromising the resection quality and subsequent patient survival. To assess the procedures used for resection and reconstruction of bone tumours invading the sacroiliac joint as well as their effects on cancer outcome and functional results. This is a continuous and retrospective analysis of 24 patients treated between 1986 and 2003. Six tumours affected the sacral body and 18 tumours involved the wing of the ilium. The joint articular surface was invaded in only six cases. Seventeen patients received neoadjuvant chemotherapy. The procedure was performed through an enlarged iliac crest incision, giving access to two sections of the pelvic ring. Six cases required neurological sacrifice. Initial tumour grading was based on the Enneking classification, and the functional results, on the Musculoskeletal Tumour Society (MSTS) scoring system. The average operation lasted 5.27 hours. Reconstruction was performed with bone autograft and instrumentation. Resection was large with adequate margins 11 times, marginal 12 times, and contaminated once. Average follow-up was 4.77 years. The 5-year survival rate was 50%. Twelve patients either died from their disease or were in the metastatic stage at final follow-up. Survival was linked to the quality of resection and initial tumour staging. Hemisacrectomy did not affect patient survival. Local recurrences had a poor prognosis with eight cases of secondary metastases out of 11. Bone healing occurred in 13 patients, 10 of whom survived. Of the 12 patients who survived and were in complete remission at final follow-up, the average MSTS score was 61%. The score was at 38.6% in cases involving neurological sacrifice, and at 77.1% for the rest of the group. It was at 64% in healed cases and 13% in nonunion cases. The survival of patients presenting with a sacroiliac joint tumour is substantially related to both tumour histology and resection quality. Local recurrences carry a poor prognosis with a high rate of secondary metastatic dissemination. In situations where disease control can be achieved, the proposed method of reconstruction allows, satisfactory bone healing and fair functional recovery, provided no major neurological sacrifice has taken place. level IV: Retrospective Therapeutic Study.

The surgical treatment of primary malignant bone tumors of pelvis

To evaluate the surgical treatment effect of primary malignant pelvic bone tumors. Retrospective study was carried out in 79 patients with primary malignant pelvic bone tumors treated surgically and followed up regularly between October 1992 and July 2007. In this cohort, 23 tumors were low-grade malignant of I B, and 56 tumors were high-grade malignant of II B. According to the preoperative diagnosis and the effect of chemotherapy, different methods of tumor resection and reconstruction were applied respectively. Surgical specimens were evaluated postoperatively for the surgical margins in accordance with Enneking's criteria. Functional results were assessed by MSTS system during follow-up. The mean time of follow-up was 28.6 months (range, 0-183 months). The minimum follow-up time in survival patients was 4 months. Seventy limb-salvage surgeries including 28 reconstructions, and 9 hemipelvectomy were carried out. In limb-salvage group, the mean MSTS functional scores both were 15 points for patients with (range, 5-29 points) or without (range, 2-30 points) reconstructions. The overall local recurrence rate was 31.6% (25/79). Statistical difference (P = 0.023) of local recurrence rate was seen between low-grade (13.0%) and high-grade (39.3%) groups. While, there was no difference (P = 0.620) between limb-salvage group (30.0%) and hemipelvectomy group (44.4%). Significant difference (P = 0.014) in local recurrence rate was found between inadequate surgical margin (intralesional and marginal margin) group (38.1%) and adequate surgical margin (wide margin) group (6.3%). In 14 patients developed postoperative distant metastasis, 12 in local recurrence group which incidence was 48.0%, compared to 2 in no-recurrence group which incidence was 3.7%, and the difference was significant (P = 0.000). The overall survival rate was 70.9%. Wide surgical margin is essential for successful resection of primary malignant pelvic bone tumors. How to choose and improve functional reconstruction is the focus of work in the future.

Insufficiency Fracture in the Para-Acetabulum, with Features Mimicking those of a Malignant Bone Tumor

Para-acetabular insufficiency fractures are rare and exceedingly difficult to diagnose without a high index of suspicion, since the images mimic those of bone tumors. We herein present the case of a 55-year-old woman who suffered from hip pain with subacute onset. She had undergone a hysterectomy-ovariectomy due to endometriosis when she was 41 years old. Her bone mineral density was normal due to supplemental treatment with female hormones. About 3 months after onset, she was referred to our institute with a diagnosis of pelvic bone tumor. Plain radiographs and computed tomography showed irregular osteosclerosis in the para-acetabulum. Bone scintigraphy demonstrated uptake in the para-acetabulum. Magnetic resonance imaging showed abnormal signal with low-signal intensity on T1-weighted images and high-signal intensity on T2-weighted images throughout the entire hemipelvic bone. Since the pain continued for more than 3 months, open biopsy was undertaken and the lesion was found to be non-neoplastic. Six months after onset, the pain disappeared. The clinical course suggested a diagnosis of insufficiency fracture in the para-acetabulum. Para-acetabular insufficiency fractures should always be considered in cases of hip pain, even in patients with prolonged symptoms.

Gelatin microspheres: Initial clinical experience for the transcatheter arterial embolization

Purpose The purpose of this study is to evaluate the embolization effects of gelatin microspheres (GMSs) when used as an embolic material for transcatheter arterial embolization (TAE) for several organs. Materials and methods We prepared GMSs that dissolves in 5 days in extravasuclar tissue. GMSs were used in five cases in total, four cases with multiple liver tumors and one case with a pelvic bone tumor. Results In all five cases, it was possible to treat the targeted tumors by TAE with GMSs. In the contrast-enhanced CT performed 2–4 weeks later, the embolized tumors did not show an enhancement effect. Passage of GMSs in the microcatheter was excellent. Conclusion GMSs showed sufficient potential to be used as an embolic material.

Pelvic Reconstruction with a Structural Pelvic Allograft After Resection of a Malignant Bone Tumor

Background: Reconstruction of the pelvic arch after resection of a malignant pelvic tumor remains a major surgical challenge because of the high rate of associated complications. The purpose of this investigation was to assess the functional outcome and complication rate following treatment with a bone allograft to reconstruct the pelvis. Methods: Twenty-four consecutive patients underwent excision of a malignant pelvic bone tumor and reconstruction with a pelvic bone allograft. The living patients were followed for a minimum of twenty-four months. There were nineteen primary malignant bone tumors, sixteen of which were high-grade sarcomas, and there were five isolated metastases. Patients were examined clinically and radiographically and were assessed functionally with the Musculoskeletal Tumor Society score. Results: The mean age of the patients at the time of the index surgery was thirty-four years, and the mean duration of follow-up was forty-one months. Eighteen of the twenty-four resections involved the periacetabular area and were followed by reconstruction either with a hip prosthesis (thirteen) or with an osteochondral allograft alone (five). The six other resections involved the iliac bone. All patients received a massive bone allograft that had been sterilely procured without secondary irradiation. At the time of our last evaluation, eight patients were alive and free of disease. Seven patients had a local recurrence. Neurological deficits were present in six patients, and three had a deep infection. Nonunion of three of the sixteen allografts that could be evaluated was observed. Neither graft fracture nor lysis was observed. Eleven patients underwent surgical revision, with nine of these revisions related to the reconstruction. The average Musculoskeletal Tumor Society score at the time of the latest follow-up was 73% of the maximal possible score. The average score was 82% for the eleven patients with an age of less than twenty years at the time of the index procedure and 65% for the thirteen older patients. Ten patients walked without any assistive device, and five of them had normal function with no or only a slight limp. Conclusions: Pelvic reconstruction after a limb-sparing resection is associated with a high risk of surgical complications and usually should be reserved for patients with a primary bone sarcoma. A pelvic allograft can restore the anatomy and provide good functional results, especially in young patients. Nonunion was the most common allograft-related complication. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.