Reconstruction of pelvic bone defect after resection for bone tumours is a challenging procedure especially when the hip joint is involved due to the anatomy and the complex biomechanical and structural function of the pelvic ring. This surgery is associated to high complication rate. The additive 3D printing technology allows us to produce trabecular titanium custom based implants with an accurate planning of resection using bone cutting jigs.

From August 2013 to January 2017, we treated 8 patients for bone pelvic sarcoma with custom-made osteotomy jigs (Nylon) and custom-made trabecular titanium prosthesis produced through rapid prototyping technology based on mirroring of the contralateral hemipelvis. Mean follow up time was 18 months (range 2–30) Wide margins were obtained in all cases, in one a local recurrence developed. Surgical time was 4 hours average (from 180 to 250 mins). No postoperative complications were reported.

Rapid prototyping is a promising technique in order to achieve wide surgical margins and restore the anatomy in pelvic bone tumour resection as well as reducing complications.

Abstract. Background. Conventional periacetabular pelvic resections are associated with poor functional outcomes. Resections through surgical corridors beyond the conventional margins may be helpful in retaining greater function without compromising the oncological margins. Methods. The study included a retrospective review of 82 cases of pelvic resections for pelvic tumors. Outcomes of acetabulum preservation (Group A) were compared with complete acetabular resection (Group B). Also, we compared outcomes of Type I+half resections (Group 1) with Type I+II resections (Group 2), and Type III+half resections (Group 3) with Type II+III resections (Group 4). Results. Group A (n=44) had significantly better functional outcome than Group B(n=38) with average MSTS93 score 22.3 vs 20.1 and average HHS 91.3 vs 82.5 (p<0.001). Group 1(n=14) and Group 2(n=12) had similar functional outcomes (mean MSTS93 score 22.07 vs 21.58 (p=0.597) and mean HHS 90.37 vs 86.51 (p=0.205)). Group 3(n=11) had significantly better functional outcome than Group 4(n=17), with mean MSTS93 score 22.8 vs 19.7 (p<0.001) and mean HHS 92.3 vs 80.1 (p<0.001). Oncological outcomes were similar among the groups. Conclusion. Trans-acetabular pelvic resections provide functional benefit over conventional resections without compromising oncological margins. There is a need to revisit and revise the pelvic resection planes

Introduction and Purposes. Custom made acetabular prosthesis are a valid option for the reconstruction after the resection of pelvic tumors. They should guarantee a stable and reliable reconstruction for the expected survival of the patient. Nevertheless in many cases periacetabular metastatic lesions have been compared to high grade (IIIA-B) Paprosky defects, but treated with low or intermediate longevity implants. Some complex post-traumatic scenarios or total hip arthroplasty (THA) multiple failures need a reconstruction according to oncologic criteria to fill in the huge defect and to obtain an acceptable function. The aim of the study is to compare 3D custom-made implants for tumors and for THA failures. Materials and Methods. Three custom-made implants after tumor resection (group A: 1 chondroblastic osteosarcoma, 1 bifasic synovialsarcoma, 1 high grade chondrosarcoma) were evaluated and compared to 3 acetabular complex reconstructions after non-oncologic bone defect (group B: 3 cases of aseptic loosening after at least 2 revisions). All the implants were case-based designed, 3D printed, and realized with porous or trabecular surfaces on a Titanium base prosthesis. Age range 16–70 ys in oncologic patients and 60–75 ys in non-oncologic patients. The bone defect to be reconstructed after tumor resection was classified according to Enneking zones (1 type 1-2-3 resection, 1 type 2 resection, 1 partial type 2 resection). Non-oncologic cases were comparable in term of remaining bone stock and classified according to Paprosky classification for acetabular defects as 1 type IIIA an 2 type IIIB. Complications, MSTS functional score, necessity of walking-aids were evaluated at minimum follow up of 1 year. Results. In both groups, good functional results were obtained (MSTS score 25/30 in both groups). No cases of aseptic loosening and no infection occured. After 3 months of partial or no weight-bearing on the operated limb, 3 patients were able to walk unaided and 3 walked with one cane or crutch. No limb length discrepancy (major than 2 cm) were observed. Limping was present in oncologic cases due to muscle resection. Overall better results in term of satisfaction and quality of life were obtained in younger (oncologic) patients. Conclusions. Complex THA revision cases can sometimes be considered for a reconstruction with oncologic criteria. Even if indications are limited an acceptable functional results can be obtained. In the past for these cases a Girldestone resection was the only option. A collaboration among orthopaedic oncologist and hip arthroplasty surgeons is advisable in major orthopaedic centers to improve the prosthetic design and the functional results

The surgical management of musculoskeletal tumours is a challenging problem, particularly in pelvic and diaphyseal tumour resection where accurate determination of bony transection points is extremely important to optimise oncologic, functional and reconstructive options. The use of computer assisted navigation in these cases could improve surgical precision. We resected musculoskeletal tumours in fifteen patients using commercially available computer navigation software (Orthomap 3D). Of the eight pelvic tumours, three underwent biological reconstruction with extra corporeal irradiation; three endoprosthetic replacement (EPR) and two required no bony reconstruction. Four diaphyseal tumours had biological reconstruction. Two patients with proximal femoral sarcoma underwent extra-articular resection and EPR. One soft tissue sarcoma of the adductor compartment involving the femur was resected with EPR. Histological examination of the resected specimens revealed tumour free margins in all cases. Post-operative radiographs and CT show resection and reconstruction as planned in all cases. Several learning points were identified related to juvenile bony anatomy and intra-operative registration. The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent to identify resection margins accurately. Furthermore, it can aid in reconstruction following tumour resection. Our experience thus far has been encouraging

Background. The surgical management of musculoskeletal tumours is a challenging problem, particularly in pelvic and diaphyseal tumour resection where accurate determination of bony transection points is extremely important to optimise oncologic, functional and reconstructive options. The use of computer assisted navigation in these cases could improve surgical precision. Materials and methods. We resected musculoskeletal tumours in fifteen patients using commercially available computer navigation software (Orthomap 3D). Results. Of the eight pelvic tumours, three underwent biological reconstruction with extra corporeal irradiation, three endoprosthetic replacement (EPR) and two required no bony reconstruction. Four diaphyseal tumours had biological reconstruction. Two patients with proximal femoral sarcoma underwent extra-articular resection and EPR. One soft tissue sarcoma of the adductor compartment involving the femur was resected with EPR. Histological examination of the resected specimens revealed tumour free margins in all cases. Post-operative radiographs and CT show resection and reconstruction as planned in all cases. Several learning points were identified related to juvenile bony anatomy and intra-operative registration. Discussion. The use of computer navigation in musculoskeletal oncology allows integration of local anatomy and tumour extent to identify resection margins accurately. Furthermore, it can aid in reconstruction following tumour resection. Our experience thus far has been encouraging

Wound complications are common in patients with soft tissue sarcomas (STS) treated with surgical excision. Limited data is available on predictive factors for wound complications beyond the relationship to neo-adjuvant or adjuvant radiotherapy. Likewise, the association between blood transfusion, patient comorbidities and post-operative outcomes is not well described. In the present study we identified the predictive factors for blood transfusion and wound complications in patients undergoing surgical resection of soft tissue sarcoma from a national cohort. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients who underwent surgical resection of a STS from 2005 to 2013. Primary malignant soft tissue neoplasms were identified using the following ICD-9 codes: 171.2, 171.3 and 171.6. Patients treated with both wide excision and amputation were identified using the current procedural terminology (CPT) codes. Prolonged operative time was defined as greater than 90th percentile of time required per procedure. A multivariable logistic regression model was used to identify associations between patient factors and post-operative wound complications (superficial and deep surgical site infections (SSI), and wound dehiscence). A similar regression model sought to identify prognostic factors for blood transfusion and associations with post-operative outcomes. A total of 788 patients met our inclusion criteria. Of theses, 64.2% had tumours in the lower limb, 23.1% patients had tumours in the upper limb, and 12.7% patients had pelvic tumours. Six hundred and forty patients (81.2%) underwent surgical excision; 148 (18.8%) patients had an amputation. Multivariable logistic regression modeling identified American Society of Anaesthesiologist (ASA) class 3 and 4 (OR=2.3, P=0.03; OR=8.3, P=0.001, respectively), amputation (OR=14.0, P<0.001) and prolonged operative time (OR=4.6, P<0.001) as significant predictors of blood transfusion. Radiotherapy (OR=2.6, P=0.01) and amputation (OR=2.6, P=0.01) were identified as predictors of superficial SSI, whereas ASA class 4 (OR=6.2, P=0.03), prolonged operative time (OR=3.9, P=0.012) and return to the operating room (OR=10.5, P<0.001) were associated with deep SSI. Male gender (OR=1.8, P=0.03), diabetes (OR=2.3, P=0.03), ASA class 3 (OR=2.4, P=0.003), amputation (OR=3.8, P<0.001) and steroids (OR=4.5, P=0.03) were identified as predictors for wound dehiscence and open SSI. A national cohort demonstrates that male gender, diabetes, chronic steroid use, higher ASA score and radiotherapy are associated with an increased incidence of wound complications. One in twenty-three patients undergoing resection of an STS will require a blood transfusion, and this risk is correlated with amputation, prolonged operative time and increased ASA score. Strategies to decrease the risk of blood transfusion and wound complication should be considered for these patient groups

Background. Advances in diagnosis and treatment should mean that hindquarter amputation is now rarely needed. Unfortunately this is not the case. We have performed 166 of these amputations in the past 36 years. We have investigated the reasons why this procedure is still required and the outcomes following it. Method. A retrospective review of data stored on a prospective database. Results. Hindquarter amputation was used as treatment for 15% of all primary bone tumours affecting the pelvis. 146 were performed with curative intent but 20 were performed purely for palliation, usually to relieve pain. 96 of the procedures were needed as part of primary treatment, with the other 70 being needed following failure of local control after other surgical procedures. The indication for amputation in primary disease was almost always due to a significant delay in diagnosis, allowing tumours (particularly chondrosarcomas) to become massive by the time of diagnosis. The peri-operative mortality was 3% and 45% had major wound healing problems or infection. The median survival times after curative and palliative procedures were 36 months and 8 months respectively. The survival after hindquarter amputation for curative intent at 1, 3 and 5 years was 74%, 60% and 48%. Overall survival was better with chondrosarcoma – 52% of the patients surviving more than 10 years had chondrosarcoma. Phantom pain was a significant problem; fewer than 10% use their prosthesis regularly. Despite this functional scores averaged 61% – not significantly worse than patients who had undergone pelvic replacements!. Conclusion. Hindquarter amputation is still regularly required both for primary and salvage treatment in musculoskeletal oncology. Earlier diagnosis of pelvic tumours may avoid its use. Survival is not surprisingly worse than for tumours at other sites

Introduction and aims. After internal hemipelvectomy for malignant pelvic tumors, pelvic reconstruction is necessary for eventual weight bearing and ambulation. Non-vascularised, fibular grafts (NVFG) offer fast, and stable reconstruction, post- modified Enneking's type I and I/IV resection. This study aimed to evaluate the success of graft union and patient function after NVFG reconstruction. Methods. From 1996 to 2009, 10 NVFG pelvic reconstructions were performed after internal hemipelvectomy in four cases of chondrosarcoma, three of Ewing's sarcoma, and single cases of osteosarcoma, malignant peripheral nerve sheath tumour, and malignant fibrous histiocytoma. A key indication for internal hemipelvectomy was sciatic notch preservation confirmed by preoperative MRI. Operation time and complications were recorded. The mean follow-up was 31.1 months (range: 5 to 56), and lower limb function was assessed using the Musculoskeletal Tumour Society scoring system. Plain radiographs and/or computer tomography were used to determine the presence or absence of NVFG union. Results. The mean operation time was four hours and 56 mins, with no major intraoperative complications and partial wound break-down in only one patient. The NVFG united successfully in all patients, with a mean union time of 7.3 months. Post-operative deep infection did not occur in any case. Seven patients were eventually able to ambulate without a cane, and overall, the average function rating percentage was 75.4%. Recurrent tumour occurred in two cases following primary resection. Death from tumour-related disease occurred in one of the ten cases. Conclusions. NVFG is a stable and reliable pelvic reconstruction method after type I and type I/IV hemipelvectomy. Reliability may be linked to preservation of graft periosteum, and careful patient selection, limited to those with an intact sciatic notch. Furthermore, the relatively short operative time required should help minimise deep infection

Ten to 15% of the pelvic girdle tumors are primary malignant bone tumors, while about 80% are osseous metastases. Due to improved function, enhanced quality of life, and acceptable local recurrence rates, limb salvage surgery has replaced external hemipelvectomies in many cases of primary malignancies. However, large segmental bony defects and poor bone quality due to the disease process itself and subsequent treatment (i.e. chemotherapy and radiation) can make stable implant fixation difficult when performing a total hip arthroplasty (THA) for oncologic periacetabular lesions with concurrent fractures. Various methods are available to reconstruct the hemipelvis, and include large structural allografts, allograft-prosthetic composites (APCs), custom-made endoprostheses, modular saddle prostheses, and modular hemipelvis endoprostheses. However, short- and mid-term results from our institution indicate that tantalum reconstructions with adjuvant screw fixation and supplemental reinforcement cages provide reasonable improvement in clinical outcomes and stable fixation in situations with massive bone loss and compromised bone quality. On the femoral side, cemented fixation remains a viable option (including proximal femoral replacements), but uncemented distal fixation with extensively-porous coated cylindrical stems or modular fluted tapered stems can be considered if the disease process (or subsequent treatment) primarily affects the proximal femur. In addition to long-term fixation, post-operative dislocations remain a significant concern given the often compromised abductor mechanism

CT and MRI scans are complementary preoperative imaging investigations for planning complex musculoskeletal bone tumours resection and reconstruction. Conventionally, tumour surgeons analyse two-dimensional (2-D) imaging information, mentally integrate and formulate a three-dimensional (3-D) surgical plan. Difficulties are anticipated with increase in case complexity and distorted surgical anatomy. Incorporating computer technology to aid in this surgical planning and executing the intended resection may improve precision. Although computer-assisted surgery has been widely used in cranial biopsies and tumour resection, only small case series using CT-based navigation are recently reported in the field of musculoskeletal tumor surgery. We investigated the results of CT/MRI image fusion for Computer Assisted Tumor Surgery (CATS) with the help of a navigation system. We studied 21 patients with 22 musculoskeletal tumours who underwent CATS from March 2006 to July 2009. A commercially available CT-based spine navigation system (Stryker Navigation; CT spine) was used. Of the 22 patients, 10 were males, 11 were females, and the mean age was 32 years at the time of surgery (range, 6–80 years). Five tumours were located in the pelvis, seven sacrum, eight femurs, and two tibia. The primary diagnosis was primary bone tumours in 16 (3 benign, 13 sarcoma) and metastatic carcinoma in four. The minimum follow-up was 17 months (average, 35.5 months; range, 17–52 months). Preoperative CT and MRI scan of each patient were performed. Axial CT slices of 0.0625mm or 1.25mm thickness and various sequences of MR images in Digital Imaging and Communications in Medicine (DICOM) format were obtained. CT and MR images for 22 cases were fused using the navigation software. All the reconstructed 2-D and 3-D images were used for preoperative surgical planning. The plane of tumour resection was defined and marked using multiple virtual screws sited along the margin of the planned resection. We also integrated the computer-aided design (CAD) data of custom-made prostheses in the final navigation resection planning for eight cases. All tumour resections could be carried out as planned under navigation guidance. Navigation software enabled surgeons to examine all fused image datasets (CT/MRI scans) together in two spatial and three spatial dimensions. It allowed easier understanding of the exact anatomical tumor location and relationship with surrounding structures. Intraoperatively, image guidance with the help of fusion images, provided precise visual orientation, easy identification of tumor extent, neural structures and intended resection planes in all cases. The mean time for preoperative navigation planning was 1.85 hours (1 to 3.8). The mean time for intraoperative navigation procedures was 29.6 minutes (13 to 60). The time increased with case complexity but lessened with practice. The mean registration error was 0.47mm (0.31 to 0.8). The virtual preoperative images matched well with the patients' operative anatomy. A postoperative superficial wound infection developed in one patient with sacral chordoma that resolved with antibiotic whereas a wound infection in another with sacral osteosarcoma required surgical debridement and antibiotic. After a mean follow-up of 35.5 months (17–52 months), five patients died of distant metastases. Three out of four patients with local recurrence had tumors at sacral region. Three of them were soft tissue tumour recurrence. The mean functional MSTS score in patients with limb salvage surgery was 28.3 (23 to 30). All patients (except one) with limb sparing surgery and prosthetic reconstruction could walk without aids. Multimodal image fusion yields hybrid images that combine the key characteristics of each image technique. Back conversion of custom prosthesis in CAD to DICOM format allowed fusion with navigation resection planning and prosthesis reconstruction in musculoskeletal tumours. CATS with image fusion offers advanced preoperative 3-D surgical planning and supports surgeons with precise intraoperative visualisation and identification of intended resection for pelvic, sacral tumors. It enables surgeons to reliably perform joint sparing intercalated tumor resection and accurately fit CAD custom-made prostheses for the resulting skeletal defect