Transarticular invasion of bone tumours across the sacroiliac joint

Imaging of spinal chordoma and benign notochordal cell tumor (BNCT) with radiologic pathologic correlation

Benign notochordal cell tumor (BNCT) and chordoma are neoplasms of notochordal differentiation. BNCT represents notochordal rests, commonly an incidental lesion present in the spine in 19% of cadaveric specimens. BNCTs are often radiographically occult. CT of BNCT frequently reveals patchy sclerosis between areas of maintained underlying trabeculae. BNCT demonstrates marrow replacement on T1-weighted MR images with high signal intensity on T2-weighting. BNCTs are frequently smaller than 35 mm and lack significant enhancement, bone destruction, cortical permeation, or soft tissue components. Biopsy or surgical resection of BNCT is usually not warranted, although imaging surveillance may be indicated. Chordoma is a rare low-grade locally aggressive malignancy representing 1-4% of primary malignant bone tumors. Chordoma is most frequent between the ages of 50-60 years with a male predilection. Clinical symptoms, while nonspecific and location dependent, include back pain, numbness, myelopathy, and bowel/bladder incontinence. Unfortunately, lesions are often large at presentation owing to diagnosis delay. Imaging of chordoma shows variable mixtures of bone destruction and sclerosis, calcification (50-70% at CT) and large soft tissue components. MR imaging of chordoma reveals multilobulated areas of marrow replacement on T1-weighting and high signal intensity on T2-weighting reflecting the myxoid component within the lesion and areas of hemorrhage seen histologically. Treatment of chordoma is primarily surgical with prognosis related to resection extent. Unfortunately, complete resection is often not possible (21-75%) resulting in high local recurrence incidence (19-75%) and a 5-year survival rate of 45-86%. This article reviews and illustrates the clinical characteristics, pathologic features, imaging appearance spectrum, treatment, and prognosis of BNCT and spinal chordoma.

Reconstruction With 3D-Printed Prostheses After Sacroiliac Joint Tumor Resection: A Retrospective Case-Control Study

Background

Sacroiliac joint tumor is rare, and the reconstruction after tumor resection is difficult. We aimed to analyze and compare the clinical effects of three-dimensional (3D) printed prostheses and bone cement combined with screws for bone defect reconstruction after sacroiliac joint tumor resection.

Methods

Twelve patients with sacroiliac joint tumors who underwent tumor resection and received 3D-printed prostheses to reconstruct bone defects in our hospital from January 2014 to December 2020 were included in the study group Twelve matched patients who underwent sacroiliac joint tumor resection and reconstruction with bone cement and screws in the same time period were selected as the control group.

Results

In the 3D-printing group, six cases were extensively excised, and six cases were marginally excised. All patients were followed up for 6–90 months, and the median follow-up time was 21 months. Among them, nine patients had disease-free survival, two survived with tumor recurrence, and one died due to tumor metastasis. The MSTS-93 score of the surviving patients was 24.1 ± 2.8. The operation time was 120.30 ± 14.50 min, and the intraoperative bleeding was 625.50 ± 30.00 ml. In the control group, seven cases were extensively excised, and five cases were marginally excised. All patients were followed up for 6–90 months, with a median follow-up time of 20 months. Among them, nine patients had disease-free survival, one survived with tumor recurrence, and two died due to tumor metastasis. The MSTS-93 score of the patients was 18.9 ± 2.6. The operation time was 165.25 ± 15.00 min, and the intraoperative bleeding was 635.45 ± 32.00 ml. There was no significant difference in survival status, intraoperative blood loss, or complications between the two groups (P>0.05). However, there were statistically significant differences in operative time and postoperative MSTS-93 scores between the two groups (P<0.05).

Conclusions

After resection of the sacroiliac joint tumor, reconstruction using 3D printed prostheses was shorter and resulted in better movement function.

Sacral tumours and their mimics: pictorial review and diagnostic strategy

Sacral tumours encompass an extensive range of differential diagnosis. The clinical presentation is often non-specific, including neurological deficits and low back pain. Accurate diagnosis of sacral lesions is challenging and requires a comprehensive imaging strategy and robust knowledge on the imaging characteristics of different pathological processes. This review will provide an updated overview of the computed tomography (CT), magnetic resonance imaging (MRI), and integrated positron-emission tomography (PET)-CT features of some common and rare sacral tumours and their mimics. Several clinical scenarios with specific diagnostic considerations and treatment implications will be described.

Sacroiliitis in cancer patients: a review of current literature

The sacroiliac (SI) joint can be directly jeopardized by malignancy and indirectly by ergonomic changes of pelvic obliquity that introduces uneven weight distribution. Cancer treatment can exacerbate preexisting arthritis and cause diffuse arthropathies, but these are unlikely to be isolated to the SI joint. The cancer population is exposed to unique stressors that might facilitate development of SI joint pain that includes cancer itself and therapy-related complications. Like the general population, cancer patients are subject to aging and BMI and musculoskeletal structural changes that affect symmetric body functioning and posturing. No frank association between sacroiliitis and cancer has been identified. Therefore, we believe there is a need to characterize any relationship between cancer and SI joint dysfunction and pain.

En Bloc Resection and Pelvic Ring Reconstruction for Primary Malignant Bone Tumors Involving Sacroiliac Joint

Objective

To observe the process of sacroiliac joint invasion by primary malignant tumors of sacrum and iliac bone, and to explore the methods of surgical resection and reconstruction.

Methods

From January 2009 to November 2017, there were nine patients with primary malignant bone tumors involving sacroiliac joints, five males and four females, aged from 16 to 63 years, with an average age of 35 years. Of these there were three cases of primitive neuroectodermal tumors, three cases of chondrosarcoma, and three cases of osteosarcoma. Pelvic ring reconstruction was performed with longitudinal half sacrum, sacroiliac joint and partial iliac bone block excision and screw‐rod system combined with bone grafting.

Results

The operation time was 155–310 min, with an average of 245 ± 55 min, and the bleeding volume was 1400–8500 ml, with an average of 3111 ± 2189 ml. Follow‐up ranged from 5 to 108 months, with a median follow‐up of 24 months. Three patients (33.3%) had local recurrence, three patients (33.3%) survived without tumors, and one patient had lung metastasis 2 years after operation, and survived with tumors. Five patients (55.6%) died, of which four died of lung metastasis and one died of brain metastasis. Survival analysis showed that the 3‐year overall survival rate was 57%. Bone grafts did not heal in four patients, and bone grafts healed in five patients. The healing time ranged from 5 to 7 months, with an average of 6.2 months. Complications: one patient developed deep infection 2 months after operation; one patient had skin edge necrosis; titanium rod loosening and displacement were found in two patients with nonunion of bone graft, and no fracture of nail rod was found. The MSTS 93 functional score of nine patients ranged from 20% to 50%, with an average of 34%.

Conclusion

The tumors around the sacroiliac joint often invade the contralateral bone by ligament, and the en bloc resection and pelvic ring reconstruction for primary malignant bone tumors involving sacroiliac joint was feasible.

Synovium as a widespread pathway to the adjacent joint in undifferentiated high-grade pleomorphic sarcoma of the tibia: A case report

RATIONALE

Undifferentiated high-grade pleomorphic sarcoma (UPS), originated from bone, is a rare tumor, accounting for 2% to 5% of all primary maligment bone neoplasms. Skip lesion can be found in undifferentiated high-grade pleomorphic sarcoma of bone (UPS-B). However, the direct invasion across the articular synovium to bone has not been reported previously.

PATIENT CONCERNS

We report an unusual case of a 65-year-old man complained of a year history of pain, swelling, and limitation of activity in the left knee joint. At the proximal tibia, there was extensive invasion of articular synovium, which provides a direct anatomic pathway for the tumor invasion to the adjacent bone, including patella and femoral condyle.

DIAGNOSES

Magnetic resonance imaging was important in defining the marrow involvement and joint invasion, including the thickening articular synovium. Subsequent pathological examination confirmed the diagnosis of UPS.

INTERVENTIONS

The patient underwent an extensive resection of the knee joint, except for the patellar.

OUTCOMES

After operation, routine chemotherapy was performed. Unfortunately, half a year later, soft tissue swelling of whole thigh was found. Then this patient came our hospital again. Positron emission tomography imaging showed there was recurrence of UPS with lung metastasis. A week later, this patient died.

LESSONS

In contrast to frequent infiltration pathway, the articular synovium as a media for this tumor spread is rare. This study adds a better understanding of this direct invasion way to the medical literature.

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.

Reconstruction of the hemipelvis with a modular prosthesis after resection of a primary malignant peri-acetabular tumour involving the sacroiliac joint

We report our early experience with the use of a new prosthesis, the Modular Hemipelvic Prosthesis II, for reconstruction of the hemipelvis after resection of a primary malignant peri-acetabular tumour involving the sacroiliac joint.

We retrospectively reviewed the outcome of 17 patients who had undergone resection of a pelvic tumour and reconstruction with this prosthesis between July 2002 and July 2010.

One patient had a type I+II+III+IV resection (ilium + peri-acetabulum + pubis/ischium + sacrum) and 16 had a type I+II+IV resection (ilium + acetabulum + sacrum). The outcome was assessed at a mean follow-up of 33 months (15 to 59). One patient was alive with disease, 11 were alive without disease and five had died of disease. The overall five-year survival rate was 62.4%. Six patients had a local recurrence. The mean Musculoskeletal Tumour Society score was 58% (33 to 77). Deep infection occurred in two patients, problems with wound healing in five and dislocation in one.

For patients with a primary malignant peri-acetabular sarcoma involving the sacroiliac joint, we believe that this new prosthesis is a viable option for reconstruction of the bony defect left following resection of the tumour. It results in a satisfactory functional outcome with an acceptable rate of complications.

Cite this article: Bone Joint J 2014;96-B:399–405.

Preservation of the contralateral sacral nerves during hemisacrectomy for sacral malignancies

PURPOSE

This study aimed to evaluate the oncologic and functional outcome of the cases treated with hemisacrectomy through a sagittal plane in the sacrum and simultaneous en bloc resection together with the ipsilateral sacroiliac joint without sacrificing the contralateral sacral nerves and summarize tumor resection techniques and reconstruction strategy.

METHODS

En bloc resection of a sacral malignancy with ipsilateral sacroiliac joint and preservation of the contralateral sacral nerves by sagittal hemisacrectomy had been performed in 15 patients. An intra-abdominal aortic balloon was used in all these cases and a combined posterior-anterior approach was adopted. A modified Galveston technique was used to reestablish spinopelvic stability and a nonvascularized fibula autograft was used in selected cases.

RESULTS

Contralateral sacral nerves were preserved in all 15 patients. Adequate margins (wide and marginal margin) were accomplished in 10 patients. Local recurrence occurred in seven (47%) patients, and four of these had an inadequate margin. There was no perioperative death. Four (27%) patients had wound problems. No mechanical breakdown occurred until the last follow-up. All the patients were able to walk without the use of a walking aid. Sphincter function was partially preserved in all these patients. At the last follow-up, seven (47%) patients survived without evidence of disease, two (13%) patients lived with disease, and six (40%) patients had died of disease.

CONCLUSIONS

This procedure has an oncologic outcome that is similar to that of other high sacrectomy and a much better function outcome. Although demanding, it is indicated in selected patients.

Imaging of sarcomas of pelvic bones

Sarcomas are the most common nonhematologic primary malignancies of bones in the pelvis. Chondrosarcoma, osteosarcoma, and Ewing's sarcoma are the most common sarcomas to originate from the pelvic bones. Various imaging modalities such as magnetic resonance imaging and computed tomography play an important role in the detection, characterization, and staging of these lesions. Biopsy, usually performed with imaging guidance, is essential for the histologic diagnosis of these tumors and for planning therapeutic options. Despite considerable advances in treatment options, sarcomas in the pelvic bones generally are associated with poorer outcomes than sarcomas in the appendicular skeleton because of the larger size of the lesions at the time of discovery and the difficulty of obtaining a wide surgical resection margin. In this review, we discuss the various types of pelvic bone sarcomas and the role of imaging in patients with these lesions.

Bone and soft tissue tumors of hip and pelvis

Objective is to identify epidemiologic and radiologic criteria allowing specific diagnoses of tumors and tumor-like lesions in the hip region and pelvis, and to optimize pre-operative staging. Patients with pelvic tumors are usually older, and their tumors are larger relative to patients with tumors in extremities. The majority of tumors in the pelvis are malignant (metastases, myeloma, chondrosarcoma, Ewing-, osteo-, and MFH/fibrosarcoma), while those in the proximal femur are in majority benign (fibrous dysplasia, solitary bone cyst, and osteoid osteoma). Soft tissue masses in the thigh in the elderly are typically sarcomas without tumor specific signs. Common tumor-like lesions occurring in the hip and pelvis that can mimic neoplasm are: infections (including tuberculosis), insufficiency/avulsion fractures, cysts, fibrous dysplasia, aneurysmal bone cyst, Langerhans cell histiocytosis, and Paget's disease. Local MR staging is based on the compartmental anatomy. The psoas and gluteal muscles are easily invaded by sarcoma originating in the ileum. The pectineus muscle protects the neurovascular bundle at the level of the hip. The thigh is separated into three compartments, some structures (Sartorius muscle) cross borders between compartments. Immobile joints (SI-joints, osteoarthritic hip) are relatively easily crossed by sarcoma and giant cell tumor.

Transarticular spread of Ewing sarcoma mimicking septic arthritis

Transarticular spread of tumor is rare; it has only been reported in the sacroiliac joint, intervertebral disk spaces, and facet joints. The anatomic and kinetic characteristics of the sacroiliac joint, as well as the changes the joint undergoes during a lifetime, make it particularly vulnerable to transarticular tumor invasion. Although extremely rare, Ewing sarcoma can extend through the sacroiliac joint and be virtually indistinguishable radiologically from septic arthritis. Furthermore, the clinical presentation of a child with Ewing sarcoma can be similar to that of a child with osteomyelitis. Laboratory values are quite nonspecific and are not always helpful in differentiating between the entities. Therefore, the possibility of sacroiliac joint transarticular Ewing sarcoma should be considered in a child presenting with hip pain, despite clinical, radiological and laboratory findings suggesting an infectious process.

Primary tumors of the osseous spine

Primary tumors of the spine are less frequent than metastatic disease, multiple myeloma, and lymphoma. MR imaging is commonly used to evaluate the spine in patients presenting with pain and can further characterize lesions that may be encountered on other imaging studies, such as radiographs, bone scintigraphy, or CT. This article guides radiologists in identifying these lesions and referring physicians to the appropriate patient evaluation. It also offers directions for avoiding all-encompassing broad differential diagnosis lists in situations where the clinical scenario or specific imaging features can significantly limit the diagnostic possibilities.

Osteoblastoma crossing the sacro-iliac joint

Osteoblastoma is a rare primary bone tumour which is well-described in the spine and sacrum. We report a case of histologically confirmed osteoblastoma in a 20-year-old male which crossed the sacroiliac joint. This has not previously been described to our knowledge. The imaging features of osteoblastoma and sacroiliac joint involvement by bone tumours are reviewed.