Internal Hemipelvectomy and Reconstruction Assisted by 3D Printing Technology Using Premade Intraoperative Cutting and Placement Guides in a Patient With Pelvic Sarcoma: A Case Report.

CASE: We describe the case of a 75-year-old patient diagnosed with high-grade epithelioid hemangioendothelioma in the left hemipelvis. She underwent an internal hemipelvectomy, followed by reconstruction with a tumor prosthesis with iliac anchorage using 3D-printed cutting and placement guides. Eighteen months postoperatively, she is pain-free and walks without appliances. CONCLUSIONS: Using 3D-printed guides could be an appropriate alternative for patients with aggressive bone tumors in the pelvic area that require hemipelvectomy and reconstruction using a prosthesis with iliac anchorage. 3D-printed cutting guides allow precise resection with appropriate margins, could reduce the risk of injuring critical structures, and facilitate proper prosthetic component positioning.

Three-dimensional printing and computer navigation assisted hemipelvectomy for en bloc resection of osteochondroma: A case report.

RATIONALE: Three-dimensional (3D) printed templates can be designed to match an individual's anatomy, allowing surgeons to refine preoperative planning. In addition, the use of computer navigation (NAV) is gaining popularity to improve surgical accuracy in the resection of pelvic tumors. However, its use in combination with 3D printing to assist complex pelvic tumor resection has not been reported. PATIENT CONCERNS: A 36-year-old man presented with left-sided pelvic pain and a fast-growing mass. He also complained of a 3-month history of radiating pain and numbness in the lower left extremity. DIAGNOSES: A biopsy revealed an osteochondroma with malignant potential. This osteochondroma arises from the ilium and involves the sacrum and lower lumbar vertebrae. INTERVENTIONS: Here, we describe a novel combined application of 3D printing and intraoperative NAV systems to guide hemipelvectomy for en-bloc resection of the osteochondroma. The 3D printed template is analyzed during surgical planning and guides the initial intraoperative bone work to improve surgical accuracy and efficiency, while a computer NAV system provides real-time imaging during the tumor removal to achieve adequate resection margins and minimize the likelihood of injury to adjacent critical structures. OUTCOMES: The tumor mass and the invaded spinal structures were removed en bloc. LESSONS: The combined application of 3D printing and computer NAV may be useful for tumor targeting and safe osteotomies in pelvic tumor surgery.

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

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

[Partial pelvic resection (internal hemipelvectomy) and endoprosthetic replacement in periacetabular tumors]. / Beckenteilresektion (innere Hemipelvektomie) und endoprothetischer Ersatz bei hüftgelenksnahen Tumoren.

OBJECTIVE: Treatment of tumors of the pelvic girdle by resection of part or all of the innominate bone with preservation of the extremity. Implantation and stable fixation using a custom-made megaprosthesis to restore painless joint function and loading capacity. The surgical goal is to obtain a wide surgical margin and local tumor control. INDICATIONS: Primary bone and soft tissue sarcomas, benign or semi-malignant aggressive lesions, metastatic disease (radiation resistance and/or good prognosis). CONTRAINDICATIONS: Limited life expectancy and poor physical status, extensive metastatic disease, persistent deep infection or recalcitrant osteomyelitis, poor therapeutic compliance, local recurrence following a previous limb-sparing resection, extensive infiltration of the neurovascular structures and the intra- and extrapelvic soft tissues. SURGICAL TECHNIQUE: Levels of osteotomy are defined preoperatively by a CT-controlled manufactured three-dimensional 1:1 model of the pelvis. Using these data, the custom-made prosthesis and osteotomy templates are then constructed by the manufacturer. The anterior (internal, retroperitoneal) and posterior (extrapelvic, retrogluteal) aspects of the pelvis are exposed using the utilitarian incision surgical approach. The external iliac and femoral vessels are mobilized as they cross the superior pubic ramus. The adductor muscles, the rectus femoris and sartorius muscle are released from their insertions on the pelvis and the obturator vessels and nerve are transected. If the tumor extends to the hip joint, the femur is transected at a level distal to the intertrochanteric line to ensure hip joint integrity and to prevent tumor contamination. A large myocutaneous flap with the gluteus maximus muscle is retracted posteriorly. The pelvitrochanteric and small gluteal muscles are divided near their insertion in the upper border of the femur. To release the hamstrings and the attachment of the sacrotuberous ligament, the ischial tuberosity is exposed. After osteotomy using the prefabricated templates, the pelvis is released and the specimen is removed en bloc. The custom made prosthesis can either be fixed to the remaining iliac bone or to the massa lateralis of the sacrum. The released muscles are refixated on the remaining bone or the implant. POSTOPERATIVE MANAGEMENT: Time of mobilization and degree of weight-bearing depends on the extent of muscle resection. Usually partial loading of the operated limb with 10 kg for a period of 6-12 weeks, then increased loading with 10 kg per week. Thrombosis prophylaxis until full weight bearing. Physiotherapy and gait training. At follow-up, patients are monitored for local recurrence and metastases using history, physical examination, and radiographic studies. RESULTS: Between 1994 and 2008, 38 consecutive patients with periacetabular tumors were treated by resection and reconstruction with a custom-made pelvic megaprosthesis. The overall survival of the patients was 58% at 5 years and 30% at 10 years. One or more operative revisions were performed in 52.6% of the patients. The rate of local recurrence was 15.8%. Deep infection (21%) was the most common reason for revision. In two of these cases (5.3%), a secondary external hemipelvectomy had to be performed. There were four cases of aseptic loosening (10.5%) in which the prosthesis had to be revised. Six patients had recurrent hip dislocation (15.8%). In four of them a modification of the inserted inlay and an implantation of a trevira tube had to be performed respectively. Peroneal palsy occurred in 6 patients (15.8%) with recovery in only two. There were 4 operative interventions because of postoperative bleeding (10.5%). The mean MSTS score for 12 of the 18 living patients was 43.7%. In particular, gait was classified as poor and almost all patients were reliant on walking aids. However, most patients showed good emotional acceptance.

Soft tissue reconstruction following hemipelvectomy: eight-year experience and literature review.

BACKGROUND AND OBJECTIVES: Hemipelvectomy is a major surgical procedure that associates with significant morbidity, functional impairment, and psychological and body image problem. Reconstruction of the defect is a challenged since a large amount of composite tissues are needed. We would like to share our eight-year experience with massive pelvic resection and reconstruction. METHODS: A retrospective analysis of all cases of hemipelvectomy was conducted in our institution over eight-year period with particular attention given to the reconstruction choices and associated complications. RESULTS: Thirteen patients were included with median age of 39 years (range 13-78) of which all had advanced tumour with stage IIb (54%) and Stage III (46%). External hemipelvectomy was performed in all cases, and resultant defects were reconstructed with variety type of flaps. These include fillet thigh flaps, regional pedicle flaps of different designs, and free flap. CONCLUSIONS: Massive pelvic tumour is rarely encountered in our population but can be seen across all age groups and usually due to late presentation. The defects should be reconstructed using local or regional flaps, incorporating the muscle component to enhance flap perfusion. The tissue should be harvested from the amputated limb, as it can limit the donor site morbidity.

Clinical effectiveness of hemipelvic reconstruction using computer-aided custom-made prostheses after resection of malignant pelvic tumors.

This is a retrospective analysis of 16 patients with primary malignant pelvic tumors who underwent wide resection of the hemipelvis and consequent reconstruction between 2003 and 2007. Mean patient age was 27 years, whereas median follow-up was 36 months (range, 23-62 months). Hemipelvic prostheses were individually designed for each patient based on preoperative computed tomographic scans and consequent surgical modeling. The 3-year prosthesis survival rate was 69%. There were 3 cases of local recurrence (19%), and 4 patients died because of pulmonary metastases. The mean follow-up Musculoskeletal Tumor Society functional score was 72%. In conclusion, computer-aided custom-made hemipelvic prosthesis can be applied to quickly and effectively restore the bone defect after internal hemipelvectomy for treatment of pelvic tumors.

[Endoprosthesis in the operative treatment of bone tumours of the pelvis]. / Stellenwert der Beckenendoprothetik in der operativen Therapie von Tumoren des knöchernen Beckens.

AIM: Limb salvage procedures in cases of bone tumours of the pelvis are established. In this retrospective study the clinical results after implantation of megaprostheses of the pelvis are reported. METHODS: Between November 1994 and September 2004 an endoprosthetic replacement of the pelvis was performed in 24 consecutive patients, fourteen females and ten males. The mean age was 49.3 years (range: 17-64 years). In ten cases a complete and in fourteen an incomplete internal hemipelvectomy was done. Thirteen patients presented with a primary bone tumour and eleven with a bone metastasis. The tumour volume ranged between 50 and 1315 ml (median: 352 ml). The mean follow-up was 98 months. RESULTS: In 23 of the 24 patients an R0 resection was achieved. Local recurrences were observed in five patients (20.8%). Deep infections developed in ten patients (41.7%) postoperatively. In two of these ten patients a secondary external hemipelvectomy was necessary. Eight patients (33.3%) developed a paralysis of the femoral and/or sciatic nerve, and a loosening of the endoprosthesis was observed in four cases (16.7%). Two patients died within 30 days postoperatively (pulmonary embolism, dissection of the abdominal aorta). Eight of the 24 patients are still alive, two of them after secondary hemipelvectomy and another after removal of the endoprosthesis due to infection. The functional results of the five surviving patients with an endoprosthesis, according to the MSTS scoring system, are good in two and poor in three patients. CONCLUSION: Internal hemipelvectomy and reconstruction of the pelvic girdle with endoprostheses is associated with a high rate of complications. Each single case should be critically evaluated and alternative procedures should be considered.

[Integration of modern technologies in therapy of sarcomas of the pelvis. Computer-assisted hemipelvectomy and implantation of a "custom-made" Bonit gentamycin coated partial pelvic prosthesis]. / Integration moderner Technologien bei der Therapie von Sarkomen des Beckens. Computerassistierte Hemipelvektomie und Implantation eines "custom-made" Bonit-Gentamycin-beschichteten Beckenteilersatzes.

The resection of primary malignancies in the pelvis is technically demanding as organs and structures are to be preserved and reconstruction of the defect as well as the postoperative function and rehabilitation are dependent on an optimal prosthesis. We present two patients with a sarcoma of the pelvis where for the first time a structured concept of technology integration led to a press-fit implantation of a hemipelvic prosthesis. This concept includes the design and production of a "custom-made" prosthesis as a hemipelvic substitute and the coating of this prosthesis with Bonit, a second-generation calcium phosphate, and gentamycin in watery solution. The tumor resection was done with computer-assisted surgery based on computed tomographies (CT) of the pelvis model done by rapid prototyping rather than on the CT of the patients' pelvis. With this procedure the presurgically simulated resection could be executed precisely with complete resection of the tumors and an accuracy which allowed an exact implantation of the prosthesis. The course was uneventful with primary healing and no sign of an infection or loosening after 6 months.

Primary Marlex-mesh reconstruction in partial resections of the hemipelvis. Report of 2 cases.

A method for immediate anatomic reconstruction of the pelvis using Marlex (nylon) mesh is described, with good results in 2 cases of chondrosarcoma subjected to partial resections of the hemipelvis.