Reconstruction of the pelvis after resection of malignant bone tumours in children and adolescents

The Diagnosis and Treatment of Osteosarcoma and Ewing's Sarcoma in Children and Adolescents

BACKGROUND

Osteosarcoma and Ewing's sarcoma in children and adolescents require age-specific interdisciplinary diagnosis and treatment to achieve optimal therapeutic outcomes.

METHODS

The diagnosis and treatment of malignant bone tumors in childhood and adolescence are presented in the light of publications retrieved by a selective search, pertinent guidelines, and the authors' extensive experience in an interdisciplinary cancer center.

RESULTS

Bone sarcomas make up approximately 5% of all malignancies in children and adolescents; the most common types are Ewing's sarcoma and osteosarcoma. Patients are often not referred to a specialized center until long after the onset of symptoms, as they and their physicians rarely consider the possibility of a bone tumor, and the symptoms are often trivialized. Bone pain of unknown origin, swelling, and functional limitations should be investigated with conventional x-rays. Lesions of unclear origin should be biopsied after a meticulous clinical and radiologic evaluation. Multimodal treatment consists of neo - adjuvant chemotherapy, limb-preserving resection if possible, and radiotherapy where indicated. In multicenter studies, patients with osteosarcoma achieve event-free survival in 64% of cases if their disease is localized, and 28% if it is metastatic; the corresponding figures for patients with Ewing's sarcoma are 80% and 27%, respectively.

CONCLUSION

With implementation of the current treatment recommendations, most children and adolescents with malignant bone tumors can be treated successfully with curative intent. These patients should be referred to a sarcoma center for diagnosis and treatment.

Pelvis reconstruction by proximal femur upshifting and total hip arthroplasty after radical resection of an adolescent patient pelvic Ewing's sarcoma, a case report, and literature review

INTRODUCTION AND IMPORTANCE

Pelvis reconstruction after tumor resection poses a challenge, especially in younger patients where preserving the patient's function and mobility is paramount.

CASE PRESENTATION

A 16 years old female presented in March 2019 with vague right iliac area pain, diagnosed as pelvic Ewing's sarcoma after imaging studies (MRI and MSCT scan) and obtaining an incisional biopsy. After initial chemotherapy cycles, the tumor decreased in size, and surgical intervention in two stages was performed. The first stage was in October 2019 and consisted of pelvic resection type I and II according to Enneking and Dunham classification, proximal femur upshifting to compensate for the pelvic bone defect, and a cement spacer to fill the space of the resected proximal femur. The second stage was performed after two months and consisted of implanting a total hip arthroplasty using Megaprostheses and a cementless dual mobility acetabular cup. No local recurrence or distant metastases were detected during follow-ups. At the final follow up after 36 months, the patient showed acceptable functional outcomes (HHS score 83, and MSTS score 23 (76.7 %) points), and the radiographs showed proper implant positioning and stability.

CLINICAL DISCUSSION

Treating pelvic Ewing's sarcoma requires a multidisciplinary team. After surgical resection, the pelvic reconstruction options include using allografts or autografts, femur upshifting, and hemipelvis prostheses, which should be chosen considering patients and tumor characteristics as well as surgical team efficiency.

CONCLUSION

Reconstructing the pelvic defect after bone tumor resection by proximal femoral upshifting is a valid biological option with acceptable outcomes.

Intra-articular Partial Acetabular Resection and Allograft Reconstruction for Synovial Sarcoma

Introduction:

The aim of this case report is to present an option of reconstruction in tumors involving the posterior wall and column of the acetabulum with sparing of the anterior column and the weight-bearing dome.

Case Report:

We are reporting a case of a 25-year-old female with histopathologically proven synovial sarcoma involving the left inferior pubic ramus, ischium, and posterior wall of the acetabulum, along with a large soft-tissue extension in the posterior and medial thigh. Wide local excision involving partial acetabular resection and reconstruction using a femoral head allograft was carried out. The patient was allowed full weight-bearing mobilization after 6 weeks. At 3 months’ follow-up, the patient was able to walk without support and was able to do active straight leg raising. There were no radiological signs of joint degeneration at the 12-month follow-up.

Conclusion:

Reconstruction with non-articular femoral head allograft can be a viable alternative after resection of tumor involving acetabulum. This procedure is expected to support the hip joint and restore function in the short term and recreate bone stock for future arthroplasty if the need arises.

Adolescent pelvic chondrosarcoma, surgical treatment, and unusual reconstruction with pedestal conic cup (LUMiC®): A case report

An 18-year-old male patient was diagnosed pelvic chondrosarcoma histopathologically. Hip joint involvement was detected. No metastasis or neurovascular invasion was seen. Type I+II pelvic resection and hip reconstruction were planned with pedestal cup (LUMiC®) and proximal femur tumor prosthesis. Surgery was performed in lateral decubitus position with extensive triradiate incision. Pelvic wide resection was performed. At the second year of follow-up, implant failure was detected and patient was revised with same pedestal cup. Axial stability was supported by a L5 screw and connector from L5 vertebrae to LUMiC® prosthesis. Except the implant failure, no oncological complication or infection was observed during the final 36^th month follow-up.

Complications following Iliac Wing Fibrosarcoma

The aim of this case report is to underline surgical strategies for complications in a case of a young man with fibrosarcoma of the bone treated with pelvic resection followed by reconstruction with massive bone allograft. A type I pelvic resection was performed as a radical resection of tumor followed by a biological reconstruction of iliac wing using frozen allograft. The iliac allograft was fixed in place using 4 screws. The immediate postoperative period was complicated with local sepsis of reconstructed site treated with pediculate omentoplasty. After 1 year from surgery, the X-ray exam showed an integrated allograft. After 20 years from the first surgery, the patient presented with the left hip pain of 3-month duration with mechanical pattern. The X-ray and CT exam showed the left hip arthritis and no signs of recurrence. A total hip arthroplasty with dual mobility cup and uncemented stem was performed. Despite the immediate postoperative local infection, the allograft was left in place and integrated after all. Omentoplasty could be a very useful technique in eradicating local infection, due to the immunogenic properties of the omentum. The allograft is still strong enough to give support for a hip arthroplasty at 20 years after implantation.

Temporary External Fixation Can Stabilize Hip Transposition Arthroplasty After Resection of Malignant Periacetabular Bone Tumors

BACKGROUND

The choice of reconstructive procedure to restore limb function is challenging after internal hemipelvectomy. Hip transposition arthroplasty, also known as resection arthroplasty, removes a malignant or aggressive tumor of the pelvis and acetabulum after which the remaining femoral head is moved proximally to the lateral surface side of the sacrum or the underside of the resected ilium after internal hemipelvectomy. It may provide reasonable functional results and have some advantages such as lowering the risk of an infected implant compared with other reconstructions because no foreign implants are used. Hip transposition is generally managed with prolonged bed rest or immobilization postoperatively to stabilize the soft tissue surrounding the remaining femur. Because enabling patients to be mobile while the soft tissues heal might be advantageous, we reviewed our experience with an external fixation for this procedure.

QUESTIONS/PURPOSES

(1) Does temporary external fixation facilitate postoperative physiotherapy in patients who undergo hip transposition arthroplasty? (2) What functional Musculoskeletal Tumor Society (MSTS) scores were achieved at short term in a small series of patients treated with hip transposition and temporary external fixation? (3) What were the complications of using external fixation in a small series of patients who received it for malignant tumors?

METHODS

Between 2008 and 2012, we treated seven patients (three men and four women; median age, 37 years; age range, 18-53 years) with acetabular resection for malignant bone tumors; all were managed with a hip transposition, initially stabilized using external fixation. No other types of procedures were used for this indication in this period. Minimum followup in this retrospective study was 45 months, except for one patient who died at 18 months (range of followup duration, 18-90 months; median followup, 57 months), and no patients were lost to followup. The pins for external fixation were inserted into the affected side of the femur and the healthy contralateral ilium. External fixation was removed 6 weeks postoperatively and weightbearing was started at that time. Preoperative chemotherapy was administrated in four patients, but postoperative chemotherapy was delayed since it was given after external fixation removal in three patients. The postoperative rehabilitation course and functional results were assessed by chart review, functional results were determined using MSTS scores, tallied by physiotherapists who were not part of the surgical team, and complications were ascertained through chart review. Major complications were defined as complications that were treated with additional operations, such as deep infection, or ones that could cause severe postoperative dysfunction, such as nerve injury.

RESULTS

With temporary external fixation, standing next to a bed was achieved in median 7 days (range, 6-9 days) postoperatively, transferring to a wheel chair in median 8 days (range, 6-28 days), and gait training using parallel bars in median 15 days (range, 7-48 days). At most recent followup, three patients could walk without a crutch or cane, three could walk with a cane, and one could walk with a crutch. The median MSTS score at most recent followup (median, 57 months) was 63%. Two patients had complications that resulted in reoperations; one had a wound dehiscence, and one had an abdominal herniation that gradually developed, and which was reconstructed using polypropylene mesh 2 years after pelvic resection. Two patients had nerve palsies that recovered by the end of the first year. All patients had pin tract infections that resolved with nonsurgical approaches.

CONCLUSIONS

Hip transposition with temporary external fixation can stabilize the bone soft tissue after pelvic resection. Although we did not have a comparison group of patients, we believe that external fixation facilitates early postoperative physiotherapy and rehabilitation and provides good functional results without major surgical complications. Because it delays the resumption of chemotherapy, more patients with longer followup are needed to determine whether this will be associated with poorer oncologic results.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Salidroside suppresses the growth and invasion of human osteosarcoma cell lines MG63 and U2OS in vitro by inhibiting the JAK2/STAT3 signaling pathway

Previous research has reported that salidroside exerts antitumor properties on numerous types of tumor cells; however, its effect on osteosarcoma cells remains unknown. The present study aimed to investigate the effects of salidroside on the viability, apoptosis and invasion of osteosarcoma cells in vitro, and determine the underlying mechanism of action. The results of an MTT revealed that salidroside suppressed the viability of osteosarcoma cells (MG63 and U2OS cells) in a time- and concentration-dependent manner. The results of cell morphological analysis (profile observations and Hoechst 33258 staining) and the detection of apoptosis by flow cytometry further indicated that the decrease in osteosarcoma cell viability induced by salidroside was associated with cell apoptosis. Western blot analysis not only confirmed these results but also suggested that salidroside induced the apoptosis of osteosarcoma cells by activating the caspase-9-dependent apoptotic pathway. In addition, we reported that salidroside induced G₀/G₁ phase arrest and suppressed the invasion of osteosarcoma cells, as measured by flow cytometric cell cycle analysis and a Transwell invasion assay, respectively. Western blot analysis confirmed the aforementioned results. Furthermore, our findings demonstrated that salidroside induced the apoptosis, G₀/G₁ phase arrest and suppressed the invasion of osteosarcoma cells by inhibiting the janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway, as determined by western blot analysis. In summary, the findings of the present study suggested that salidroside may inhibit the progression of osteosarcoma by suppressing the growth and invasion of osteosarcoma cells. Furthermore, the investigations into the underlying mechanism demonstrated that salidroside exerted notable antitumor activity in osteosarcoma cells by inhibiting the JAK2/STAT3 signaling pathway.

Acetabular Reconstruction With Femoral Head Autograft After Intraarticular Resection of Periacetabular Tumors is Durable at Short-term Followup

BACKGROUND

Pelvic reconstruction after periacetabular tumor resection is technically difficult and characterized by a high complication rate. Although endoprosthetic replacement can result in immediate postoperative functional recovery, biologic reconstructions with autograft may provide an enhanced prognosis in patients with long-term survival; however, little has been published regarding this approach. We therefore wished to evaluate whether whole-bulk femoral head autograft that is not contaminated by tumor can be used to reconstruct segmental bone defects after intraarticular resection of periacetabular tumors.

QUESTIONS/PURPOSES

In a pilot study, we evaluated (1) local tumor control, (2) complications, and (3) postoperative function as measured by the Musculoskeletal Tumor Society score.

METHODS

Between 2009 and 2015, we treated 13 patients with periacetabular malignant or aggressive benign tumors with en bloc resection, bulk femoral head autograft, and cemented THA (with or without a titanium acetabular reconstruction cup), and all were included for analysis here. During that time, the general indications for this approach were (1) patients anticipated to have a good oncologic prognosis and adequate surgical margins to allow this approach, (2) patients whose pelvic bone defects did not exceed two types (Types I + II or Types II + III as defined by Enneking and Dunham), and (3) patients whose medical insurance would not cover what otherwise might have been a pelvic tumor prosthesis. During this period, another 91 patients were treated with pelvic prosthetic replacement, which was our preferred approach. Median followup in this study was 36 months (range, 24-99 months among surviving patients; one patient died 8 months after surgery); no patients were lost to followup. Bone defects were Types II + III in five patients, and Types I + II in eight. After intraarticular resection, ipsilateral femoral head autograft combined with THA was used to reconstruct the segmental bone defect of the acetabulum. In patients with Types I + II resections, the connection between the sacrum and the acetabulum was reestablished with a fibular autograft or a titanium cage filled with dried bone-allograft particles which was enhanced by using a pedicle screw and rod system. Functional evaluation was done in 11 patients who remained alive and maintained the femoral head autograft at final followup; one other patient received secondary resection involving removal of the femoral head autograft and internal fixation, and was excluded from functional evaluation. Endpoints were assessed by chart review.

RESULTS

Two patients experienced local tumor recurrence. Finally, eight patients did not show signs of the disease, one patient died of disease for local and distant tumor relapse, and four patients survived, but still had the disease. Three of these four patients had distant metastases without local recurrence and one had local control after secondary resection but still experienced system relapse. We observed the following complications: hematoma (one patient; treated surgically with hematoma clearance), delayed wound healing (one patient; treated by débridement), deep vein thrombosis (one patient), and hip dislocation (one patient; treated with open reduction). The median 1993 Musculoskeletal Tumor Society score was 83% (25 of 30 points; range, 19-29 points), and all patients were community ambulators; one used a cane, three used a walker, and nine did not use any assistive devices.

CONCLUSIONS

In this small series at short-term followup, we found that reconstruction of segmental bone defects after intraarticular resection of periacetabular tumors with femoral head autograft does not appear to impede local tumor control; complications were in the range of what might be expected in a series of large pelvic reconstructions, and postoperative function was generally good.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

LUMiC® Endoprosthetic Reconstruction After Periacetabular Tumor Resection: Short-term Results

BACKGROUND

Reconstruction of periacetabular defects after pelvic tumor resection ranks among the most challenging procedures in orthopaedic oncology, and reconstructive techniques are generally associated with dissatisfying mechanical and nonmechanical complication rates. In an attempt to reduce the risk of dislocation, aseptic loosening, and infection, we introduced the LUMiC^® prosthesis (implantcast, Buxtehude, Germany) in 2008. The LUMiC^® prosthesis is a modular device, built of a separate stem (hydroxyapatite-coated uncemented or cemented) and acetabular cup. The stem and cup are available in different sizes (the latter of which is also available with silver coating for infection prevention) and are equipped with sawteeth at the junction to allow for rotational adjustment of cup position after implantation of the stem. Whether this implant indeed is durable at short-term followup has not been evaluated.

QUESTIONS/PURPOSES

(1) What proportion of patients experience mechanical complications and what are the associated risk factors of periacetabular reconstruction with the LUMiC^® after pelvic tumor resection? (2) What proportion of patients experience nonmechanical complications and what are the associated risk factors of periacetabular reconstruction with the LUMiC^® after pelvic tumor resection? (3) What is the cumulative incidence of implant failure at 2 and 5 years and what are the mechanisms of reconstruction failure? (4) What is the functional outcome as assessed by Musculoskeletal Tumor Society (MSTS) score at final followup?

METHODS

We performed a retrospective chart review of every patient in whom a LUMiC^® prosthesis was used to reconstruct a periacetabular defect after internal hemipelvectomy for a pelvic tumor from July 2008 to June 2014 in eight centers of orthopaedic oncology with a minimum followup of 24 months. Forty-seven patients (26 men [55%]) with a mean age of 50 years (range, 12-78 years) were included. At review, 32 patients (68%) were alive. The reverse Kaplan-Meier method was used to calculate median followup, which was equal to 3.9 years (95% confidence interval [CI], 3.4-4.3). During the period under study, our general indications for using this implant were reconstruction of periacetabular defects after pelvic tumor resections in which the medial ilium adjacent to the sacroiliac joint was preserved; alternative treatments included hip transposition and saddle or custom-made prostheses in some of the contributing centers; these were generally used when the medial ilium was involved in the tumorous process or if the LUMiC^® was not yet available in the specific country at that time. Conventional chondrosarcoma was the predominant diagnosis (n = 22 [47%]); five patients (11%) had osseous metastases of a distant carcinoma and three (6%) had multiple myeloma. Uncemented fixation (n = 43 [91%]) was preferred. Dual-mobility cups (n = 24 [51%]) were mainly used in case of a higher presumed risk of dislocation in the early period of our study; later, dual-mobility cups became the standard for the majority of the reconstructions. Silver-coated acetabular cups were used in 29 reconstructions (62%); because only the largest cup size was available with silver coating, its use depended on the cup size that was chosen. We used a competing risk model to estimate the cumulative incidence of implant failure.

RESULTS

Six patients (13%) had a single dislocation; four (9%) had recurrent dislocations. The risk of dislocation was lower in reconstructions with a dual-mobility cup (one of 24 [4%]) than in those without (nine of 23 [39%]) (hazard ratio, 0.11; 95% CI, 0.01-0.89; p = 0.038). Three patients (6%; one with a preceding structural allograft reconstruction, one with poor initial fixation as a result of an intraoperative fracture, and one with a cemented stem) had loosening and underwent revision. Infections occurred in 13 reconstructions (28%). Median duration of surgery was 6.5 hours (range, 4.0-13.6 hours) for patients with an infection and 5.3 hours (range, 2.8-9.9 hours) for those without (p = 0.060); blood loss was 2.3 L (range, 0.8-8.2 L) for patients with an infection and 1.5 L (range, 0.4-3.8 L) for those without (p = 0.039). The cumulative incidences of implant failure at 2 and 5 years were 2.1% (95% CI, 0-6.3) and 17.3% (95% CI, 0.7-33.9) for mechanical reasons and 6.4% (95% CI, 0-13.4) and 9.2% (95% CI, 0.5-17.9) for infection, respectively. Reasons for reconstruction failure were instability (n = 1 [2%]), loosening (n = 3 [6%]), and infection (n = 4 [9%]). Mean MSTS functional outcome score at followup was 70% (range, 33%-93%).

CONCLUSIONS

At short-term followup, the LUMiC^® prosthesis demonstrated a low frequency of mechanical complications and failure when used to reconstruct the acetabulum in patients who underwent major pelvic tumor resections, and we believe this is a useful reconstruction for periacetabular resections for tumor or failed prior reconstructions. Still, infection and dislocation are relatively common after these complex reconstructions. Dual-mobility articulation in our experience is associated with a lower risk of dislocation. Future, larger studies will need to further control for factors such as dual-mobility articulation and silver coating. We will continue to follow our patients over the longer term to ascertain the role of this implant in this setting.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Reconstruction After Hemipelvectomy With the Ice-Cream Cone Prosthesis: What Are the Short-term Clinical Results?

BACKGROUND

Reconstruction after internal hemipelvectomy resection likely provides better function than hindquarter amputation. However, many reconstruction methods have been used, complications with these approaches are common, and function often is poor; because of these issues, it seems important to investigate alternative implants and surgical techniques.

QUESTIONS/PURPOSES

The purposes of this study were (1) to identify the frequency of surgical site complications and infection associated with the use of the Ice-Cream Cone prosthesis for reconstruction after hemipelvectomy for oncological indications; (2) to evaluate the Musculoskeletal Tumor Society (MSTS) outcomes scores in a small group of patients treated with this implant in the short term; and (3) to quantify the surgical margins and frequency of local recurrence in the short term in this group of patients.

METHODS

Between 2008 and 2013, one center performed a total of 27 internal hemipelvectomies for oncological indications. Of those, 23 (85%) were treated with reconstruction. Our general indications for reconstruction were patients whose pelvic stability was affected by the resection and whose general condition was sufficiently strong to tolerate the reconstructive procedure. Of those patients undergoing reconstruction, 14 (61%) were treated with an Ice-Cream Cone-style implant (Coned^®; Stanmore Worldwide Ltd, Elstree, UK; and Socincer^® custom-made implant for the pelvis, Gijón, Spain), whereas nine others were treated with other implants or allografts. The indications during this time for using the Ice-Cream Cone implant were pelvic tumors affecting the periacetabular area without iliac wing involvement. Of those 14, 10 were available for followup at a minimum of 2 years (median, 3 years; range, 2-5 years) unless a study endpoint (wound complication, infection, or local recurrence) was observed earlier. Study endpoints were ascertained by chart review performed by one of the authors.

RESULTS

Surgical site complications occurred in five patients. Of those, two developed superficial infections with necrosis, two developed deep infections, and one patient developed wound necrosis without apparent infection. No prostheses were removed as a result of these complications [corrected]. Median MSTS score was 19 out of 30 when 0 is the worst possible result and 30 a perfect function and emotional status. Five of seven primary tumors had wide margin surgery and three of seven developed local recurrences by the end of the followup.

CONCLUSIONS

Pelvic reconstruction with the Ice-Cream Cone prosthesis yielded fair functional results at short-term followup. Longer term surveillance is called for to see whether this implant will represent an improvement over available reconstructive alternatives such as allograft, custom-made implants, and saddle prostheses. We are cautiously optimistic and continue to use this implant when we need to reconstruct the periacetabular area in patients without Enneking Zone 1 involvement.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Review of the outcomes of complex acetabular reconstructions using a stemmed acetabular pedestal component

Aim

Until now, there has been no consensus as to whether stemmed acetabular components are appropriate for use in patients undergoing revision total hip arthroplasty (THA) who have major acetabular defects or pelvic discontinuity. We wished to address this deficiency in the literature.

Patients and Methods

We carried out a retrospective study of 35 patients (six men and 29 women) with a mean age of 68 years (37 to 87), with major acetabular defects who underwent revision THA between 2000 and 2012.

Results

At a mean follow-up of 63 months (24 to 141), a total of 15 patients (43%) had required at least one further operation. Six implants (17%) loosened aseptically, four (11%) were further revised for infection and two (6%) for technical failure. By taking revision for any reason as the endpoint, the rate of survival of the implant was 61% after five years; by taking revision for aseptic loosening as the end point, it was 78%. The cumulative five-year survival for aseptic loosening was 94% in patients without pelvic discontinuity, and 56% in those with pelvic discontinuity.

Conclusion

These results indicate a significantly worse survival in patients with pelvic discontinuity (p = 0.020) and we advise caution in the use of the pedestal component in patients with major acetabular defects and pelvic discontinuity who require revision THA. As a result of these findings we have stopped using this implant and prefer to use particulate bone grafts protected with an anti-protrusion cage and posterior column plate fixation, if necessary. Take home message: Based on these poor results, we advise caution if using the pedestal component in patients with major acetabular defects with the presence of a pelvic discontinuity. Cite this article: Bone Joint J 2016;98-B:772–9.

Type 3 internal hemipelvectomy: a report of two cases

Type 3 internal hemipelvectomy involves resection of the pubis. We report on 2 patients who underwent type 3 internal hemipelvectomy. One patient developed a bladder hernia, tumour recurrence, and a pathological fracture of the proximal femur. These were resolved with external hemipelvectomy 7 months later. Another patient underwent additional fascia lata transplantation to prevent development of hernia. Both patients had a stress fracture in the contralateral posterior ilium mimicking bone metastasis.

[Hemipelvectomy for the treatment of high-grade sarcomas: Pronostic of chondrosarcomas compared to other histological types]

INTRODUCTION

The low incidence and histological heterogeneity of primary sarcomas located in the pelvis makes it difficult to find homogeneous cohorts.

OBJECTIVE

To describe the life and functional prognosis depending on the histological type of sarcoma in a series of locally advanced high-grade pelvis located sarcomas treated by hemipelvectomy.

METHODS

A descriptive epidemiological and functional study was conducted on 15 cases treated between 2006 and 2012. Survival analysis, functional assessment, and a comparative study by histological type were performed, comparing chondrosarcomas to other histological diagnoses.

RESULTS

The most frequent histological type was chondrosarcoma (46%), and the most frequent location was P2 (periacetabular) (73%). An internal hemipelvectomy was performed in 66% of cases, with a higher incidence (83%) in chondrosarcomas. Overall two-year survival was 54%, with higher survival in the chondrosarcoma group (67%) than in the other sarcomas (43%). Functional status depended on the type of intervention, with no differences in histological type or the performance of the reconstruction.

DISCUSSION AND CONCLUSIONS

Hemipelvectomy is a surgical procedure that is indicated for the treatment of locally advanced high grade pelvis located sarcomas, regardless of histological type. The incidence of limb preservation and overall survival is higher in chondrosarcomas compared to other sarcomas.

Ewing sarcoma of the acetabulum in children: a "growth plate-based" surgical strategy

BACKGROUND

Surgical strategy for Ewing sarcoma (ES) of the pelvis relies on Enneking classification. In adults, in case the acetabulum is involved, excision of the entire acetabulum is needed and often leads to loss of function. In children, the surgeon may adopt a strategy, such as in metaphyseal tumors of long bones where an unaffected growth plate allows a transepiphyseal resection, therefore sparing the joint.

METHODS

We present a "triradiate cartilage strategy" for the excision of ES of the pubic component of the acetabulum, which allows a wide resection while preserving most of the socket. The approach is ilioinguinal. Osteotomies of the iliopubic and ischio pubicrami are performed, followed by hip arthrotomy and anterior dislocation. Transacetabular resection is achieved using osteotomes, under image intensifier guidance, with no further reconstruction. Cases are presented for 2 boys aged 6.5 and 9.5 years, treated with chemotherapy and transacetabular resection.

RESULTS

Resections were all rated R0. Patient #1 remained asymptomatic, including during sport activities, and had normal hip range of motion at 12-year follow-up. Radiograph demonstrated mild protrusio acetabuli. Patient #2 had no complain at 3-year follow-up with normal hip range of motion, although he presented with an equinus gait. Radiographs demonstrated a well-covered femoral head without medial shift.

CONCLUSIONS

A "growth plate-based" surgical strategy can be adapted to malignant pelvic tumors in skeletally immature children. This technique leaves intact the ilio ischiatic component of the triradiate cartilage, which, according to Ponseti, contributes the most to the growth of the acetabulum. Joint sparing improves the functional result and decreases the risk of complication.

LEVEL OF EVIDENCE

IV.

What are the functional results and complications from allograft reconstruction after partial hemipelvectomy of the pubis?

BACKGROUND

In patients undergoing hemipelvectomies including resection either of a portion of the pubis or the entire pubis from the symphysis to the lateral margin of the obturator foramen while sparing the hip (so-called Dunham Type III hemipelvectomies), reconstructions typically are not performed given the preserved continuity of the weightbearing axis and the potential complications associated with reconstruction. Allograft reconstruction of the pelvic ring may, however, offer benefits for soft tissue reconstruction of the pelvic floor and hip stability, but little is known about these reconstructions.

QUESTIONS/PURPOSES

(1) What is the postoperative functional status after allograft reconstruction of Type III pelvic defects? (2) What are the rates of hernia, infection, and hip instability?

METHODS

In this case series, we reviewed all patients with Type III pelvic resections (with or without anterior acetabular wall resections) who underwent allograft reconstruction between 2005 and 2013 at one center (N = 14). During the period in question, reconstruction was the general approach used in patients undergoing these resections; during that time, three other patients were treated without reconstruction as a result of either surgeon preference or the patient choosing to not have reconstruction after a discussion of the risks and benefits. Of the 14 patients treated with reconstruction, complete followup was available at a minimum of 1 year in 11 (other than those who died before the end of the first year; median, 19 months; range 16-70 months among those surviving), one was lost to followup before a year, and two others had partial telephone or email followup. Patient demographics, disease status, functional status, and complications were recorded. For a portion of the cohort (four patients) later in the series, we used a novel technique for anterior acetabular wall reconstruction using the concave cartilaginous surface of a proximal fibula allograft; the others received either a long bone (humerus or femur) or hemipelvis graft. Seven patients died of disease; two had local recurrence, and five died of metastatic disease.

RESULTS

All patients remained ambulatory Pain at 12 months after surgery was reported as none in five, mild in two, moderate in two, and severe in one. Operative complications included infection in two, symptomatic hernia in one, hip instability in one, dislocated total hip arthroplasty on the first postoperative day in one, and graft failure in one.

CONCLUSIONS

Allograft reconstruction after Type III pelvic resections can provide functional reconstruction of the pelvic ring, pelvic floor, and, in certain patients with partial anterior acetabular resections, the resected anterior acetabulum. This has implications in preventing the occurrence of hernia and hip instability in this patient population that is classically not reconstructed, although longer-term outcomes in a larger number of patients would help to better delineate this because infection, hernia, hip instability, and graft nonunion still remain concerns with this approach. The most important unanswered question remains whether, on balance, any benefits that may accrue to these patients as the result of reconstruction are offset by a relatively high likelihood of undergoing secondary or revision surgery.

Clinical outcome of pedestal cup endoprosthetic reconstruction after resection of a peri-acetabular tumour

Peri-acetabular tumour resections and their subsequent reconstruction are among the most challenging procedures in orthopaedic oncology. Despite the fact that a number of different pelvic endoprostheses have been introduced, rates of complication remain high and long-term results are mostly lacking.

In this retrospective study, we aimed to evaluate the outcome of reconstructing a peri-acetabular defect with a pedestal cup endoprosthesis after a type 2 or type 2/3 internal hemipelvectomy.

A total of 19 patients (11M:8F) with a mean age of 48 years (14 to 72) were included, most of whom had been treated for a primary bone tumour (n = 16) between 2003 and 2009. After a mean follow-up of 39 months (28 days to 8.7 years) seven patients had died. After a mean follow-up of 7.9 years (4.3 to 10.5), 12 patients were alive, of whom 11 were disease-free. Complications occurred in 15 patients. Three had recurrent dislocations and three experienced aseptic loosening. There were no mechanical failures. Infection occurred in nine patients, six of whom required removal of the prosthesis. Two patients underwent hindquarter amputation for local recurrence.

The implant survival rate at five years was 50% for all reasons, and 61% for non-oncological reasons. The mean Musculoskeletal Tumor Society score at final follow-up was 49% (13 to 87).

Based on these poor results, we advise caution if using the pedestal cup for reconstruction of a peri-acetabular tumour resection.

Cite this article: Bone Joint J 2014;96-B:1706–12.

Robotic guidance for en bloc sacrectomy: a case report

STUDY DESIGN

Case report of a patient with primary osteosarcoma of the sacrum who underwent en bloc sacrectomy.

OBJECTIVE

To describe a novel approach using robotic guidance for sacral tumor resection.

SUMMARY OF BACKGROUND DATA

En bloc sacrectomy for aggressive primary malignancies or metastatic tumors of the sacrum can be technically challenging. Although imaging can delineate appropriately planned resection margins, the complex anatomy of the spinopelvic junction poses a challenge for the exact intraoperative execution of the preoperative plan.

METHODS

The patient was a 22-year-old male who was diagnosed with a primary sacral osteosarcoma. The mass extended to the left sacroiliac joint requiring a transiliac osteotomy. Preoperative robotic-guidance software was used allowing for virtual planning of the transiliac osteotomy.

RESULTS

During surgery, the robot was attached and synchronized with the preoperative imaging. Pilot holes were drilled along the planned iliac resection margin. With rigid tubes placed in the left iliac pilot holes, we passed a series of osteotomes parallel to the tubes to the same depth as our drillings and completed our left iliac osteotomy. Negative tumor margins were achieved and the postoperative course was uneventful.

CONCLUSION

We report the first case of robotic-guided en bloc transiliac resection of a primary sacral osteosarcoma with extension to the sacroiliac joint. Robotic guidance for tumor resection can be a useful tool in such challenging surgical procedures to fully resect the tumor, while minimizing disruption of the surrounding healthy anatomy.

LEVEL OF EVIDENCE

5.

Outcome of surgical resection of pelvic osteosarcoma

BACKGROUND

The aim of the following study is to evaluate the morbidity, oncologic results and functional outcome in nonmetastatic patients with primary osteosarcoma of the pelvis treated with surgical resection.

MATERIALS AND METHODS

Twelve cases of nonmetastatic osteosarcoma of pelvis were operated as part of their multimodality treatment regime between November 2003 and May 2011. There were 5 males and 7 females with a median age of 22 years (range 8-39 years). Ten patients underwent limb sparing resections while 2 had a hindquarter amputation. All 10 cases of limb sparing surgery included resection of the acetabulum. A pseudarthrosis was carried out in 7 cases. Extracorporeal radiation therapy and reimplantation of the bone followed by fixation with plates was used in 1 case and an ischiofemoral arthrodesis was carried out in 2 cases.

RESULTS

Surgical margins were free in 11 patients. Seven patients had a poor histological response to chemotherapy while 4 patients had a good response to chemotherapy. In the patient reconstructed with radiated auto bone graft, the histological response to chemotherapy could not be assessed. Surgery related complications were seen in 8 out of 12 patients (67%). Three of these patients (25%) required additional surgical intervention for their complications. All patients were available for followup. The median followup of survivors was 56 months (range 24-102 months). Four patients (33%) developed a local recurrence. At 5 years, overall survival was 67%. Patients with a good response to chemotherapy had a better overall survival when compared with patients with a poor response to chemotherapy. The mean Musculoskeletal Tumor Society functional score was 22 (range12-27).

CONCLUSIONS

Though complex and challenging, surgery provides good local control and oncologic outcomes with acceptable function in patients with osteosarcoma of the pelvis treated with appropriate surgical resection as part of their multimodality treatment.

Outcomes after limb sparing resection in primary malignant pelvic tumors

AIM

To evaluate morbidity, oncologic results and functional outcome in patients with malignant tumors of pelvis treated with limb sparing resection.

METHODS

Between March 2002 and November 2010, 106 cases of non metastatic malignant pelvic tumors were treated with limb sparing resections of pelvis. Diagnosis included chondrosarcoma (65), Ewing's sarcoma (25), osteogenic sarcoma (10), synovial sarcoma (3) and malignant fibrous histiocytoma, high grade sarcoma, epitheloid hemangiothelioma (1 each). Three patients had intralesional surgery because of erroneous pre-operative diagnosis of benign tumor and were excluded from final analysis. Remaining 103 patients underwent limb sparing resections with intent to achieve tumor free margins. In 1 case, an intraoperative cardiac event lead to the surgery being abandoned. Reconstruction was done in 2 of 38 cases that did not include resection of acetabulum. For 64 resections involving acetabulum various reconstruction modalities were used.

RESULTS

Surgical margins were involved in 20 patients. Forty five patients had complications. 91 patients were available for follow up. Follow up of survivors ranged from 24 to 122 months (mean 55 months).Twenty one patients (23%) had local recurrence. Sixty patients are currently alive, 46 being continuously disease free. Overall survival was 67% at 5 years. Patients in whom acetabulum was retained had better function (mean MSTS score 27) compared to patients in whom acetabulum was resected (mean MSTS score 22).

CONCLUSIONS

Though complex and challenging, limb sparing surgery in non metastatic malignant tumors is oncologically safe and has better functional outcomes than after an amputation surgery.

Synergistic apoptotic effect of crocin and cisplatin on osteosarcoma cells via caspase induced apoptosis

Crocin is well-known traditional Chinese medicine which is extracted from saffron. However, its role in osteosarcoma has not been well understood. Therefore, we used crocin and cisplatin individually or jointly on MG63 and OS732 cells so as to explore whether crocin could induce cellular apoptosis and suppress the ability of invasion of osteosarcoma cells. Cell survival rates, changes of cellular shape, cell apoptosis and cell invasion were analyzed, respectively, by 3-(4,5)-dimethylthiahiazo (-z-y1)-2,5-di- phenytetrazoliumromide (MTT) assay, inverted phase contrast microscope and fluorescence microscope, flow cytometry, and Transwell invasion chamber methods. The expressions of caspase-3 and caspase-8 were detected by Western blot. The survival rate of combined application was significantly lower than that of the individual application. Apoptosis-inducing effect of combined application was much stronger than that of individual application. The invasion ability of MG63 and OS732 cells was restrained significantly in the combined group compared with the individual group and control group. Combined group has the effect of up-regulating the expressions of cleaved-caspase-3 and caspase-8. The results suggested that combination of crocin and cisplatin has a strong killing effect on osteosarcoma cells and suppresses the ability of invasion of MG63 and OS732 cells which might be related to up-regulate the expression of caspase-3 and caspase-8.

Expressional Analysis of GFP-Tagged Cells in an In Vivo Mouse Model of Giant Cell Tumor of Bone

Giant cell tumor of bone in a neoplastic stromal cell which survives for multiple passages in primary cell culture with a stable phenotype. In the pathological environment of GCT, the neoplastic nature of the mesenchymal stromal component drives local hematopoietic precursors to undergo fusion and form multinucleated osteoclast like giant cells. There is currently very limited knowledge about the pathogenesis of GCT due to the lack of suitable in vivo models for this tumor. Here we report stable gene transfer of Green fluorescence protein (GFP) in GCT stromal cells. In the present study, we have used GCT stromal cells that stably express enhanced green fluorescence protein (GFP) that are used in a new in vivo culture model. Our results show the utility of the GFP tagged cell lines that stably express GFP signals up to 52 weeks of continuous growth. The in vivo model described herein can serve as an excellent system for in vivo therapeutic and mechanistic evaluation of existing and novel targets for GCT.

Pelvic reconstruction with allogeneic bone graft after tumor resection

OBJECTIVES

: Pelvic reconstruction after tumor resection is challenging.

METHODS

A retrospective study had been preformed to compare the outcomes among patients who received pelvic reconstructive surgery with allogeneic bone graft after en bloc resection of pelvic tumors and patients who received en bloc resection only.

RESULTS

Patients without reconstruction had significantly lower functional scores at 3 months (10 vs. 15, P = 0.001) and 6 months after surgery (18.5 vs. 22, P = 0.0024), a shorter duration of hospitalization (16 day vs. 40 days, P < 0.001), and lower hospitalization costs (97,500 vs. 193,000 RMB, P < 0.001) than those who received pelvic reconstruction. Functional scores were similar at 12 months after surgery (21.5 vs. 23, P = 0.365) with no difference in the rate of complications between the two groups (P > 0.05).

CONCLUSIONS

: Pelvic reconstruction with allogeneic bone graft after surgical management of pelvic tumors is associated with satisfactory surgical and functional outcomes. Further clinical studies are required to explore how to select the best reconstruction method. Level of Evidence IV, Case Series.

Results of surgical resection in pediatric pelvic tumors

Thirty nonmetastatic patients with malignant tumors of the pelvis underwent surgical resection between November 2000 and December 2009. The diagnosis included Ewing's sarcoma (22), osteogenic sarcoma (four), chondrosarcoma (two), and synovial sarcoma (two). Eighteen resections included the acetabulum and 12 did not. Twenty-seven patients were available for follow-up. Follow-up ranged from 4 to 138 months (mean 43 months). Nineteen patients are currently alive. There were two local recurrences. The overall survival was 68% at 5 years. The Musculoskeletal Tumor Society Score ranged from 22 to 29. Surgery provides good local control and oncologic outcomes with acceptable function in these patients.

Iliosacral resections of pelvic malignant tumors and reconstruction with nonvascular bilateral fibular autografts

BACKGROUND

Iliosacral resection of pelvic malignant tumors and subsequent reconstruction have tested the ingenuity of orthopedic oncologists because of the difficulty of oncological wide resection and the complex biomechanics of the sacroiliac joint render reconstruction challenging. This study compared the functional and surgical outcomes of a biological reconstruction technique with the lack of reconstruction following iliosacral resection.

METHODS

Twenty-six consecutive cases with malignant iliac tumors involving the sacrum were retrospectively reviewed. These cases underwent iliosacral resection (type I/IV) followed by no reconstruction or a biological reconstruction blinded to authors between 1997 and 2007. After iliosacral resection, 12 cases underwent reconstruction with nonvascular fibular grafts and plate and/or pedicle screw-rod; the other 14 cases did not undergo reconstruction.

RESULTS

The median follow-up was 84.42 (range, 32-165) months. The local recurrence rate in the reconstruction group was 8.33 % (1/12) with 14.29 % (2/14) in the group without reconstruction. The functional score of the biological reconstruction group was significantly higher than that of the no-reconstruction group as determined by Student's t test. In the biological reconstruction group, bone fusion occurred in 91 % of cases and fibula hypertrophy was observed in 41.7 %. Complications included sciatic nerve palsy, broken screws, intractable pain, nonunion, pelvic oblique, and leg-length discrepancy.

CONCLUSIONS

After iliosacral resections of pelvic malignant tumors, the biologic reconstruction of these defects could restore spinopelvic stability and continuity. The double-barrel fibular autograft combined with the plate or pedicle screw-rod system is an effective reconstruction method for both optimal short- and long-term stability.

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.

Clinical and functional outcomes of the saddle prosthesis

BACKGROUND

The implantation of a saddle prosthesis after resection of a pelvic tumor has been proposed as a simple method of reconstruction that provides good stability and reduces the surgical time, thus limits the onset of intraoperative complications. There are no studies in the literature of patients evaluated using gait analysis after being implanted with a saddle prosthesis. The present study is a retrospective case review aimed at illustrating long-term clinical and functional findings in tumor patients reconstructed with a saddle prosthesis.

MATERIALS AND METHODS

A series of 15 patients who received pelvic reconstruction with a saddle prosthesis were retrospectively reviewed in terms of clinical, radiographic, and functional evaluations. Two patients were additionally assessed by gait analysis.

RESULTS

Long-term functional follow-up was achieved in only 6 patients, and ranged from 97 to 167 months. Function was found to be rather impaired, as a mean of only 57 % of normal activity was restored. Gait analysis demonstrated that the implant had poor biomechanics, as characterized by very limited hip motion.

CONCLUSIONS

Though the saddle prosthesis was proposed as advance in tumor-related pelvic surgery, the present study indicates that it yields unsatisfactory clinical and functional results due to both clinical complications and the poor biomechanics of the device. The use of a saddle prosthesis in tumor surgery did not provide satisfactory results in long-term follow-up. It is no longer implanted at our institute, and is currently considered a "salvage technique."