Die endoprothetische Versorgung an den Extremit�ten bei Kindern nach Resektion prim�r maligner Knochentumoren

Custom-Made 3D-Printed Implants as Novel Approach to Reconstructive Surgery after Oncologic Resection in Pediatric Patients

Recently, custom-made 3D-printed prostheses have been introduced for limb salvage surgery in adult patients, but their use has not been described in pediatric patients. A series of 11 pediatric patients (mean age 10.8 years; range 2-13) with skeletal tumors treated with custom-made implants for the reconstruction of bony defects is described. Patients were followed up every 3 months. Functional results were evaluated by the Musculoskeletal Tumor Society Score (MSTS) for upper and lower limbs. The mean follow-up was 25.7 months (range 14-44). Three patients died after a mean of 19.3 months postoperatively-two because of disease progression and the other from a previous malignancy. Three patients experienced complications related to soft tissues. One patient required device removal, debridement, and antibiotic pearls for postoperative infection. Partial osseointegration between grafts and host bone was observed within a mean of 4 months. At the final follow-up, mean MSTS score was 75%. 3D prostheses may yield biological advantages due to possible integration with the host bone and also through the use of vascularized flaps. Further research is warranted.

[Current results of tumour endoprosthetics in adolescents and adults]

BACKGROUND

The majority of osteoarticular defects after tumor resection in adolescent and adult patients are reconstructed using megaendoprosthetic implants. However, even infant and pre-teen children undergo reconstruction of defects using so-called growing prostheses with an increasing frequency.

OBJECTIVES

Presentation of current techniques, outcomes and the most common complications of megaendoprosthetic reconstruction following tumour resection.

METHODS

Selective literature review and discussion of current concepts and knowledge in megaendoprosthetic reconstruction against personal experience and treatment strategies.

RESULTS

Megaendoprosthetic reconstructions achieve good functional results and long-term limb salvage (ca. 90% of cases) in adolescent and adult patients. Still, periprosthetic infection and mechanical failure of joint components are among the most common complications observed. In infant and pre-teen children treated by reconstruction using a growing prosthesis, mandatory maintenance operations-in the process of elongating the implant-must also be considered when assessing complication risks.

CONCLUSIONS

Megaendoprosthetic reconstructions of osteoarticular defects are a standard procedure in adolescent and adult patients. Despite a substantial complication rate, limb salvage is achieved in a majority of patients. When using growing prostheses in younger children, one needs to be aware of additional servicing procedures that occur independently of those arising from complications.

Prognostic factors and survival in Ewing's sarcoma treated by limb salvage surgery

PURPOSE

Survival in Ewing's sarcoma (ES) has increased with the use of chemotherapy. Surgical techniques such as limb salvage (LS) have been developed. Survival and adverse events have been widely studied in general series of ES, but there are few specific series of ES cases treated by LS, despite this being the most commonly used (surgical) approach. The aim of this study was to determine survival and prognostic factors in ES patients undergoing LS.

PATIENTS AND METHODS

We analysed all ES patients treated between January 1984 and May 2008 and selected all those treated by systemic multimodal therapy and LS. We assessed the influence of patient characteristics, tumour parameters and therapeutic results in event-free survival (EFS).

RESULTS

Ninety patients were included. Fifty of them were treated by systemic multimodal therapy and locally by LS. ean age was 20 years. Overall survival (OS) was 68.8% and EFS was 60.6% at years. In the univariate analysis, pelvic location, age and response to chemotherapy were associated with poor prognosis. After multivariate analysis, poor response to treatment, pelvis location and age between 12 and 17 years were found to be independent prognostic factors. Dissemination at diagnosis was not a prognostic factor.

CONCLUSIONS

OS and EFS in ES treated by LS were similar to findings in previous ES studies. factors are no different, except for the presence of metastasis at diagnosis.

A NEW APPROACH TO PARTIALKNEE ENDOPROSTHESIS IN PRIMARY BONE SARCOMAS

Partial knee endoprosthesis to bone sarcomas resections seems to be a good solution to treat this immature skeletal patients. The purpose of this study is to evaluate the functional score in fourteen patients, advantages and the technique indications. Methods: Retrospective analysis was done to assess in this group of patients the functional evolution and the possible complications of the procedure. 14 patients between 10 and 22 years functionally evaluated in Ennekin/ISOLS (International Society of Limb Salvage) criteria, being all of them operated in the same institution by the same surgeon. Were used distal femur and proximal tibia partial endoprosthesis. Results: General analysis demonstrated that the functional results were over than 67 percent (ISOLS criteria) in 78,6 percent of the patients, being considered excellent. 21,4 percent were considered good results, being between 50 and 66 percent. Bone storage was preserved when avoiding the adjacent segment resection. Surgery time was not prolonged in ligament reconstruction. Conclusion: Knee partial endoprosthesis are less damage to bone storage in young patients. The critics about the bad functional results are being supplied by new surgical techniques, excellent rehabilitation protocols, implants technology and the consequent learning curve. This option of treatment permits the preservation of healthy bone and provides the possibility of a revision replacement less aggressive.

The long-term outcomes following the use of inactivated autograft in the treatment of primary malignant musculoskeletal tumor

Background

Biological reconstruction surgery is a tough but alluring option for treating primary malignant musculoskeletal tumors. In this article, we evaluate the clinical outcomes of primary malignant musculoskeletal tumors treated with inactivated autograft using alcohol.

Method

In this article, we include 58 patients who had primary malignant bone tumors treated with wide resection and recycling autograft reconstruction using alcohol between January 2003 and January 2013. The outcomes were measured by recurrence, functional status, and complications. Functional status was assessed according to the Musculoskeletal Tumor Society Score (MSTSS). The Kaplan-Meier survival curve was used to evaluate the survival rate of the patient.

Result

The most common tumor was osteosarcoma (31 cases) followed by chondrosarcoma (10 cases). The tibia was the most frequently involved skeletal site (27 cases) followed by femur (26 cases). The median follow-up period was 54 months, ranging from 18 to 96 months. In 58 patients, 12 were with local recurrence (20.7 %), 16 with lung metastasis (27.6 %), and 13 with complications (22.4 %). The main complication was infection (8 cases). The autografts survived in 49 patients (84.5 %). The mean MSTSS score was 78.5 %, ranging from 47 to 98 %.

Conclusion

Recycling autograft reconstruction using alcohol had favorable clinical outcomes to some degree; however, the recurrence and complication rates seem to be high. Thus, we should apply this method with caution and choose the patients with strict surgical indication.

Progress in musculoskeletal oncology from 1922 - 2012

Since 1922 surgical approaches toward limb salvage in bone and soft tissue tumours have been documented. There is the famous "Umkippplastik" of Sauerbruch, the "Tikhoff-Linberg" inter-scapulo-thoracic resection or in 1943 a metallic tumour prosthesis for the hip joint in the United States (Moore, Bohlman). Since 1960 acrylic prostheses and metallic prosthesis with bone cement have been in use. Cement-free implants and the first modular ceramic prostheses were implanted in the 1970s in Vienna. At the same time successful chemotherapy in bone sarcomas was introduced by Gerald Rosen and Norman Jaffe. This was mainly the decade of custom-made prostheses. In the 1980s modular tumour prostheses with cone connection to be adopted to the needs of the patient were built intra-operatively. Since 1981 biannual international meetings (ISOLS) have pushed forward the field of bone tumour treatment to allow also tumour resection in wide borders for spine and pelvic tumours. New hope for resistant tumours could be monoclonal antibodies or even dendritic cell therapy.

Total condylar unipolar expandable prosthesis for proximal tibia malignant bone tumors in early childhood

Wide resection and reconstruction of tumors of the proximal tibia in the pediatric population are challenging procedures. The use of hinged, expandable prostheses may cause early closure of the distal femoral growth plate, which may increase the risk of limb discrepancy already present in this population. Between 1991 and 2001, 2 girls and 1 boy, aged 6, 6, and 4 years, respectively, were diagnosed with osteosarcoma of the proximal tibia and treated with wide resection and reconstruction with a condylar unipolar expandable tibial prosthesis. A press-fitted technique was used for component insertion. All patients received neoadjuvant and adjuvant chemotherapy. Radiographic and functional follow-up took place at least once a year for a minimum of 4 years. Adequate pain control, limb-length equality, and acceptable function were obtained in all patients. One patient presented with significant range of motion reduction (0°- 30°) in the affected knee. Limb lengthening was performed as needed to maintain balanced limb length. All patients had a good Musculoskeletal Tumor Society category score. No complications occurred in terms of component loosening or infection. One patient died shortly after 4-year follow-up because of doxorubicin-induced leukemia. Currently used hinged, expandable prostheses can jeopardize the unaffected distal femoral growth plate. This article describes a technique of reconstruction that spares the distal femoral growth plate. Adequate limb length can be expected with acceptable functional outcome. However, it is imperative to keep in perspective the expectations of the physician, the physician's team, the patient, and the patient's family.

Impaction bone grafting with proximal and distal femoral arthroplasty

Capacious diaphyses and poor bone stock in revision arthroplasty can lead to fracture and poor component fixation. Impaction bone grafting can be performed in salvage reconstructions in cases with extensive circumferential bone loss. We present a consecutive series of patients who underwent proximal or distal femoral reconstructions in combination with impaction bone grafting. The average age was 62 years, and the mean follow-up was 36 months (range, 24-84). No revisions were performed for mechanical failure, and radiographs revealed no evidence of implant loosening. No patient complained of end-of-stem thigh pain. There were 3 failures: 1 for periprosthetic fracture, 1 for instability, and 1 for infection. Impaction bone grafting can be used in combination with proximal and distal femoral arthroplasty to successfully manage cases with extensive bone loss after failed hip and knee arthroplasty. The procedure reconstitutes necessary bone stock, improves stress shielding, and provides immediate fixation in capacious canals.

Analysis of limb function after various reconstruction methods according to tumor location following resection of pediatric malignant bone tumors

Background

In the reconstruction of the affected limb in pediatric malignant bone tumors, since the loss of joint function affects limb-length discrepancy expected in the future, reconstruction methods that not only maximally preserve the joint function but also maintain good limb function are necessary. We analysis limb function of reconstruction methods by tumor location following resection of pediatric malignant bone tumors.

Patients and methods

We classified the tumors according to their location into 3 types by preoperative MRI, and evaluated reconstruction methods after wide resection, paying attention to whether the joint function could be preserved. The mean age of the patients was 10.6 years, Osteosarcoma was observed in 26 patients, Ewing's sarcoma in 3, and PNET(primitive neuroectodermal tumor) and chondrosarcoma (grade 1) in 1 each.

Results

Type I were those located in the diaphysis, and reconstruction was performed using a vascularized fibular graft(vascularized fibular graft). Type 2 were those located in contact with the epiphyseal line or within 1 cm from this line, and VFG was performed in 1, and distraction osteogenesis in 1. Type III were those extending from the diaphysis to the epiphysis beyond the epiphyseal line, and a Growing Kotz was mainly used in 10 patients. The mean functional assessment score was the highest for Type I (96%: n = 4) according to the type and for VFG (99%) according to the reconstruction method.

Conclusion

The final functional results were the most satisfactory for Types I and II according to tumor location. Biological reconstruction such as VFG and distraction osteogenesis without a prosthesis are so high score in the MSTS rating system. Therefore, considering the function of the affected limb, a limb reconstruction method allowing the maximal preservation of joint function should be selected after careful evaluation of the effects of chemotherapy and the location of the tumor.

Megaprosthesis versus Condyle-sparing intercalary allograft: distal femoral sarcoma

Although functionally appealing in preserving the native knee, the condyle-sparing intercalary allograft of the distal femur may be associated with a higher risk of tumor recurrence and endoprosthetic replacement for malignant distal femoral bone tumors. We therefore compared the risk of local tumor recurrence between patients in these two types of reconstruction groups. We retrospectively reviewed 85 patients (mean age, 22 years; range, 4-82 years), 38 (45%) of whom had a condyle-sparing allograft and 47 (55%) of whom had endoprostheses. The minimum followup for both groups was 2 years (mean, 7 years; range, 2-19 years). Local recurrences occurred in 11% (five of 47) of the patients having implants versus 18% (seven of 38) of the patients having allografts. Using time to local recurrence as an end point, the Kaplan-Meier survivorship of the implant group was similar to that of the condyle-sparing allograft group at 2, 5, and 10 years (93% versus 87% at 2 years, 87% versus 81% at 5 years, and 87% versus 81% at 10 years, respectively). The condyle-sparing allograft procedure offers the potential advantage of retaining the native knee in a young patient population while incurring no greater risk of local recurrence as those offered the endoprosthetic procedure.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Osteosarcoma: the COSS experience

COSS, the interdisciplinary Cooperative German-Austrian-Swiss Osteosarcoma Study Group, was founded in 1977 and has since registered some 3,500 bone sarcoma patients from over 200 institutions. For the purpose of the Pediatric and Adolescent Osteosarcoma Conference in Houston, March 2008, the outcomes of 2,464 consecutive patients with high-grade central osteosarcoma, who had been diagnosed between 1980 and 2005 and had been treated on neoadjuvant COSS protocols, were reviewed. Intended treatment had included surgery and multidrug chemotherapy, with high-dose methotrexate, doxorubicin, cisplatin, and ifosfamide being used in most protocols. After a median follow-up of 7.31 years for 1,654 survivors, 5- and 10-year survival estimates were 0.748/0.695 for 2,017 patients with localized extremity tumors and 0.369/0.317 for 444 patients with axial tumors or/and primary metastases, respectively. Tumor response to preoperative chemotherapy was of independent prognostic significance. Over the years, there was a major shift from amputation towards limb-salvage. This development was least evident for patients below the age of 10. While survival expectancies improved from the first to the second half of the recruitment period, no further improvement was evident within the latter period. In the manuscript, the results described above are discussed based on the findings of the previous analyses of our group.

Modular endoprosthetic reconstruction in malignant bone tumors: indications and limits

Modular tumor prostheses are well established today for the reconstruction of osseous defects after resection of malignant bone tumors. Almost every joint and even total bones (e.g., total femur or humerus) can be replaced with promising functional results, dramatically reducing the need for ablative procedures. Although the complication rate with the use of modern modular endoprostheses is constantly decreasing, the need for revision surgery is still significantly higher than in primary joint arthroplasty. In this review we present the modular endoprosthesis system developed in our institution, summarize the postoperative management, and discuss the indications, limits, and complications as well as the functional results.

Bone tumors in adolescents and young adults

OPINION STATEMENT

Bone tumors, particularly osteosarcomas and members of the Ewing Sarcoma Family of Tumors (ESFT), are typical malignancies of adolescents and young adults. Current diagnostic and therapeutic guidelines for patients of all ages were developed in this specific age group. The aim of bone sarcoma therapy should be to cure the patient from both the primary tumor and all (micro-)metastatic deposits while maintaining as much (extremity) function and causing as few treatment-specific late effects as possible. Bone sarcoma therapy requires close multidisciplinary cooperation. Usually, it consists of induction chemotherapy, followed by local therapy of the primary tumor (and, if present, primary metastases) and further, adjuvant chemotherapy. Local treatment for osteosarcoma should be surgery whenever feasible. Surgery is also gaining importance in ESFT, which was long considered a domain of radiotherapy. Modern reconstructive techniques continue to expand the indications for limb salvage, particularly for patients who have not yet reached skeletal maturity. Treatment within the framework of prospective, multi-institutional trials should be considered standard of care not only for children, but also for affected adolescents and (young) adults. Such trials are essential in guaranteeing that all patients have access to appropriate care and that progress from biological studies can be translated into prognostic improvements without undue delay. The rarity of bone sarcomas increasingly requires trials to be multinational.

The use of prostheses in skeletally immature patients

Prosthetic reconstruction in the skeletally immature patient is challenging because of the necessity to cope with expected disruption of limb growth after resection of one or more major growth plates and the high demands placed on implants by young patients. Although prosthetic reconstruction in children is fraught with many problems, it is usually possible to obtain a good functional limb at skeletal maturity. Extendable prostheses are readily acceptable to patients and their parents. The availability of noninvasive extendable prostheses is expected to lead to fewer complications, fewer surgical interventions, and even improved function. This article reviews the indication, evolution, and clinical and functional results of extendable endoprostheses, drawing from experience in the last 30 years of using such prostheses in children.