Tumor Endoprostheses Research Articles

Treatment of pediatric bone tumors around the knee

Primary bone tumors are rare but more frequently seen during childhood and with predilection for the distal femur and proximal tibia. Therapy of benign tumors-if indicated-includes surgical resection in most cases, whereas malignant bone tumors such as osteo- and Ewing's sarcomas are treated with chemotherapy, wide resection and/or radiation therapy (Ewing's sarcoma). The reconstruction of emerging bone defects is significantly influenced by surgeon-related preferences and tumor-associated factors, respectively. Double-barrel vascularized fibula grafts or extracorporeally irradiated autografts in combination with afree fibula transplant are preferred biological reconstruction techniques around the knee joint. In cases in which the knee joint cannot be preserved, reconstruction is performed using tumor endoprostheses, but potentially emerging leg length discrepancies after resection of apotent physis must be taken into account. In considerably young patients, rotationplasty might represent aviable option with promising functional results.

Not every knee tumour is a ganglion - retrospective analysis of benign and malign tumour entities around the knee.

Due to a lack of routine, there is often uncertainty regarding diagnostics of tumours around the knee joint. This study aimed to provide knowledge about the frequency, distribution and diagnostic algorithm of different bone and soft tissue tumour entities of the knee at a large referral university hospital in Germany. Retrospective, longitudinal, single-centre study that reviewed adult patients from 2010 until 2020 with a suspected tumours diagnosis around the knee at a university cancer centre. Inclusion criteria were adults with true bone or soft-tissue tumours in the knee joint and in its adjacent compartments. Suspected diagnosis, histological tumour entity, localization and its surgical treatment by biopsy, resection, osteosynthesis or tumour endoprosthesis were investigated. A total number of 310 adult patients were included with a mean age of 54.2 ± 18.8 years. In total 160 (51.6%) soft-tissue tumours (69/43.1% benign; 74/46.2% malignant; 17/10.6% intermediate), 92 (29.6%) primary bone tumours (46/50% benign; 39/42.3% malignant; 7/7.6% intermediate), 36 (11.6%) metastases and 22 (7.1%) lymphomas were detected. 171 (55.1%) tumours were classified as malignant. Suspected diagnosis was matched with histology in 74.5% (231/310) of all cases. In 6 cases a primarily suspected benign diagnosis turned out to be malignant. The majority of primary bone tumours was cartilage derived (63.1%;58/92) and located in the distal 2/3 of the femur, whereas intracapsular tumours of the knee joint were rare (13.0%). Soft-tissue tumours were located primarily in the middle third of the thigh (36.8%). The MRI was the diagnostic tool of choice in 98.1% of soft tissue tumours and 82.6% bone tumours. Awareness is crucial for detecting rare and malignant tumours around the knee, with adipocytic tumours being the most common soft tissue tumour and chondrogenic tumours as the most prevalent malignant bone tumour. Accurate diagnosis of bone tumours necessitates radiographs and frequently an additional MRI scan, while soft tissue tumours require mandatory MRI scans. Incorrectly diagnosing a tumour can have severe consequences, emphasizing the need for histological confirmation in all cases. Additionally, malignant tumours within joint capsules in adults are infrequent.

Individualized surgical treatment of sarcomas of the extremities

Sarcomas of the extremities are rare entities, the treatment of which requires special expertise. Even if the treatment of patients is always interdisciplinary, the surgical R0 resection is the key point of each curatively intended treatment. In addition to resection in sano, the aim is to preserve the extremities and function, so that defect reconstruction after resection plays adecisive role. Due to the heterogeneity of tumors as well as their localization and extent, reconstruction is always an individually adapted treatment. Modular tumor endoprostheses are often used in this context, which can be constructed according to the size of the defect. The transplantation of autologous or allogeneic bone is also frequently used alone or as an additive procedure. Patient-specific (mega)prostheses are used particularly for pelvic tumors. Defect reconstruction using scaffold-based procedures from the field of tissue engineering is being tested as apromising procedure for the future. This article provides an overview of the treatment principles for sarcomas of the extremities and their individual reconstruction options.

Older age at surgery and postoperative leg length discrepancy are risk factors for unfavourable patient-reported outcome measures of knee tumour endoprostheses following resection for musculoskeletal tumour of the lower limb.

To evaluate mid-to long-term patient-reported outcome measures (PROMs) of endoprosthetic reconstruction after resection of malignant tumours arising around the knee, and to investigate the risk factors for unfavourable PROMs. The medical records of 75 patients who underwent surgery between 2000 and 2020 were retrospectively reviewed, and 44 patients who were alive and available for follow-up (at a mean of 9.7 years postoperatively) were included in the study. Leg length discrepancy was measured on whole-leg radiographs, and functional assessment was performed with PROMs (Toronto Extremity Salvage Score (TESS) and Comprehensive Outcome Measure for Musculoskeletal Oncology Lower Extremity (COMMON-LE)) with two different aspects. The thresholds for unfavourable PROMs were determined using anchor questions regarding satisfaction, and the risk factors for unfavourable PROMs were investigated. The thresholds for favourable TESS and COMMON were 64.8 and 70.4 points, respectively. Multivariate analysis showed that age at surgery (p = 0.004) and postoperative leg length discrepancy (p = 0.043) were significant risk factors for unfavourable TESS results, while age at surgery (p < 0.001) was a significant risk factor for unfavourable COMMON-LE results. Following receiver operating characteristic analysis, the threshold for both TESS and COMMON-LE was 29 years of age at surgery. Additionally, a leg length discrepancy of 8.2 mm was the threshold for unfavourable TESS. Patients aged > 29 years at the time of surgery require appropriate preoperative counselling and adequate postoperative physical and socioemotional support. Reconstruction equivalent to the length of the resected bone can reduce the risk of functional disabilities in daily living.

The use of distraction osteogenesis for the reconstruction of bone defects following resection of malignant bone tumours

The reconstruction of extensive bone defects following resection of malignant bone tumours is achallenge and is mainly influenced by tumour-related factors. In defect reconstructions using distraction osteogenesis isotropic, high-quality (new) bone is formed. For the reconstruction of bone defects and secondary limb length discrepancies following tumour resection, predominately threetechniques have been described: bone transport, primary shortening and secondary lengthening, as well as "bio-expandable tumour endoprostheses". The use of distraction osteogenesis represents an excellent method for defect reconstruction and treatment of secondary limb length discrepancies following bone tumour resection. Due to the complex anatomical preconditions in tumour patients, ahigh degree of expertise in distraction osteogenesis (and tumour endoprostheses) is paramount. Therefore, treatment of these patients at highly specialised centres is recommended.

Outcomes of two-stage revision of endoprostheses of the lower-limb in oncology surgery: Limb-salvage

BackgroundTwo-stage revision remains the gold standard to eradicate deep infection of endoprosthetic replacements following bone tumour removal. We aim to (1) report the infection eradication and limb-salvage rate with two-stage revision surgery and to (2) report the common causative microorganisms. Patients and methodsA retrospective review of 44 consecutive patients who underwent two-stage revision surgery to treat periprosthetic joint infection was conducted between 1999 and 2018 ​at a tertiary orthopaedic oncology centre from prospectively collated oncology database. Patients’ mean age was 36.1 years (range 12–78 years). The sites of prosthesis were distal femur in 22 patients (50%), proximal femur in five patients (11%), proximal tibia in 16 patients (36%) and total femur with proximal tibia replacement in one patient (2%). The mean duration of follow-up was 96 months (6–251 months). ResultsInfection was eradicated in 26 patients (59%). The infection-free survival was 93% (CI 85–100%) at two years, 78% (66–92%) at five years and 61% (46–80%) at 10 years. 11 patients (25%) had amputation following failure of limb-salvage surgery. The amputation-free survival was at 100% at two years, 89% (79–100%) at five years and 73% (58–92%) at 10 years. Polymicrobial infection was reported in 8 patients (18%) and multi-drug resistance in 14 patients (32%). Coagulase-negative staphylococcus was the commonest microorganism isolated in 21 patients (48%). ConclusionTwo-stage revision is a reliable approach to achieve limb-salvage. Infected tumour endoprostheses have a high rate of multi-drug resistance and polymicrobial infections. PJI recurrence still has a high rate of amputation.

Incidence and risk of surgical site infection/periprosthetic joint infection in tumor endoprosthesis—data from the nationwide bone tumor registry in Japan

BackgroundSurgical site infection (SSI)/periprosthetic joint infection (PJI) is a devastating complication in limb salvage surgery with endoprosthesis reconstruction for malignant bone tumors. The main bottleneck for data collection and analysis for the status of SSI/PJI in tumor endoprosthesis is the low absolute case numbers of this rare cancer. The accumulation of many cases is possible by administrating nationwide registry data. MethodsThe data on malignant bone tumor resection with tumor endoprosthesis reconstruction were extracted from the Bone and Soft Tissue Tumor Registry in Japan. The primary endpoint was defined as the need for additional surgical intervention for infection control. The incidence of postoperative infection and its risk factors were analyzed. ResultsA total of 1342 cases were included. The incidence of SSI/PJI was 8.2%. The incidence of SSI/PJI in the proximal femur, distal femur, proximal tibia, and pelvis were 4.9%, 7.4%, 12.6%, and 41.2%, respectively. Location in the pelvis or proximal tibia, tumor grade, indication of myocutaneous flaps, and delayed wound healing proved to be independent risks for SSI/PJI, whereas age, sex, previous surgery, tumor size, surgical margin, application of chemotherapy and radiotherapy were not significant. ConclusionsThe incidence was equal to those in previous studies. The result reconfirmed the high incidence of SSI/PJI in pelvis and proximal tibia cases and cases with delayed wound healing. Novel risk factors such as tumor grade and application of myocutaneous flaps were marked. The administration of nationwide registry data was informative for the analysis of SSI/PJI in tumor endoprosthesis.

Blood-saving dissection with monopolar tungsten needle electrodes and Teflon-coated spatula electrodes in tumor orthopedics

IntroductionResection of musculoskeletal tumors and reconstruction with tumor endoprostheses often results in blood loss requiring transfusion of blood products. We assessed the blood-saving potential of using monopolar tungsten needle electrodes and polytetrafluoroethylene (PTFE)-coated spatula electrodes (intervention) compared with conventional dissection with sharp instruments and coagulation with uncoated steel electrodes (control).MethodsWe retrospectively analyzed data of 132 patients (79 interventions, 53 controls) undergoing surgery by one single experienced surgeon in our tertiary referral center between 2012 and 2021.ResultsIntraoperative blood loss in the intervention group was reduced by 29% [median (IQR): 700 (400–1200) vs 500 (200–700) ml; p = 0.0043]. Postoperative wound drainage decreased by 41% [median (IQR): 1230 (668–2041) vs 730 (450–1354) ml; p = 0.0080]. Additionally, patients in need of PRBCs during surgery declined from 43% to 15% (23/53 vs 12/79; p = 0.0005), while the transfusion rate after surgery did not change notably. The number of patients in need of revision surgery due to wound healing disorders was low in both groups (control group: 4/53 vs intervention group: 4/79). Only one patient in the control group and two patients in the intervention group underwent revision surgery due to hemorrhage. Baseline characteristics were similar between groups (sex, Charlson Comorbidity score, tumor entity).ConclusionDissection with tungsten needle electrodes and PTFE-coated spatula electrodes appears an effective surgical blood-saving measure without increased risk of wound healing disorders.Level of evidenceIII, retrospective comparative study.Clinical trial registration. The study was registered at ClinicalTrials.gov. Identifier: NCT05164809.

Functional results after reconstruction with modular tumor endoprostheses in patients with malignant bone tumors

The functional outcome in patients after limb salvage surgery, and in particular reconstructions with modular tumor endoprostheses, has been the subject of many international series, but only a few publications mention the functionality in a Bulgarian patient group. The aim of the present study was to analyze the functional outcome in a Bulgarian group of patients with malignant bone tumors that underwent resection and reconstruction with modular tumor endoprostheses. Our series consists of 14 patients with malignant bone tumors who underwent limb salvage surgery and reconstruction with modular tumor endoprostheses between February 2012 and January 2021. Staging was done using the AJCC staging system for bone sarcoma. The MSTS score system was used to evaluate the functional results. The mean follow-up time was 38.5 months (range, 8 to 96). The mean MSTS score for our series was 70%. Distant metastases were found in 4 (28%) patients. Local recurrence occurred in 3 (21%) patients. The most severe late complication was a mechanical failure of the expanding mechanism in 1 patient. Reconstruction with modular tumor endoprostheses offer superb functionality and improved life quality in patients with primary malignant bone tumors.

Our Experience with the Modular Universal Tumour and Revision System in Pediatric Patients with Ewing's Sarcoma – Report of Six Cases

Ewing’s sarcoma (ES) usually affects patients between 10 and 19 years of age and has a rapid progression. The main goal of surgical treatment is to remove the tumour with at least wide margins, limb salvage being achievable in most cases. In recent years, modular tumour endoprostheses have become one of the main methods used in children. From August 2012 to May 2019, six patients with histologically diagnosed ES underwent limb salvage surgery and reconstruction with a MUTARS® type endoprosthesis. The mean age of the patients is 12.6 years (from 8 to 16). For the reconstruction in all six patients we used MUTARS® type endoprostheses, two of which were expandable (MUTARS® Xpand) (33.33%). The average follow-up period was 40 months. The longest follow-up was 96 months. The average MSTS score one month after operative treatment and rehabilitation was 62% (18/30) and the average MSTS score after 12 months was 72% (21/30). Mechanical failure of the expanding mechanism was the main complication we encountered in our series. In conclusion limb salvage surgeries and reconstruction with modular tumour endoprostheses give patients with Ewing’s sarcoma not only a chance for a disease-free life, but a potentially functional limb.

Functional outcome and quality of life following resection of the proximal humerus performed for musculoskeletal tumors and reconstruction done by four different methods.

The proximal humerus is a frequent site for both primary and secondary bone tumors. Several options are currently available to reconstruct the resected humerus, but there is no consensus regarding optimal reconstruction. The aim of this retrospective study was to compare the functional outcome, complications and patient compliance following four different types of reconstructive techniques. The authors performed 90 proximal humerus resections due to primary and secondary bone tumors over the past 21years. Four different procedures were performed for reconstruction following the resection: fibula autograft transplantation, osteoarticular allograft implantation, modular tumor endoprosthesis (hemiarthroplasty) and reconstruction of the defect with a reverse shoulder prosthesis-allograft composite. A retrospective analysis of the complications and patient's physical status was performed. Functional outcome and life quality was evaluated by using the MSTS and SF-36 scores. The best range of motion was observed following arthroplasty with a reverse shoulder prosthesis-homograft composite followed by a fibula autograft reconstruction. Revision surgery was required due to major complications most frequently in the osteoarticular allograft group, followed by the reverse shoulder prosthesis-allograft composite group, the autologous fibula transplantation group; the tumor endoprosthesis hemiarthroplasty group had superior results regarding revision surgery (40, 25, 24 and 14% respectively). MSTS was 84% on average for the reverse shoulder prosthesis-allograft composite group, 70% for the autologous fibula group, 67% for the anatomical hemiarthroplasty group and 64% for the osteoartricular allograft group. Using the SF-36 questionnaire for assessment no significant differences were found between the four groups regarding quality of life. Based on the results of our study the best functional performance (range of motion and patient compliance) was achieved in the a reverse prosthesis-allograft combination group-in cases where the axillary nerve could be spared. The use of an osteoarticular allograft resulted in unsatisfying functional results and high complication rates, therefore we do not recommend it as a reconstructive method following resection of the proximal humerus due to either primary or metastatic bone tumors. Young patients who have good life expectancy but a small humerus or intramedullar cavity reconstruction by implantation of a fibula autograft is a good option. For patients with a poor prognosis (i.g. bone metastases) or in cases where the axillary nerve must be sacrificed, hemiarthroplasty using a tumor endoprosthesis was found to have acceptable results with a low complication rate. According to the MSTS and SF-36 functional scoring systems patients compliance was nearly identical following all four types of reconstruction techniques; the underlying cause may be the complexity of the shoulder girdle. However, we recommend the implantation of a reverse shoulder prosthesis-allograft whenever indication is appropriate, as it has been demonstrated to provide excellent functional outcomes, especially in young adults.

The Use of Megaprostheses in Severe Bone Loss due to Nononcological Indications: Three Case Reports and Literature Review

Reconstruction of severe bone loss and large skeletal defects using biologic materials with autograft or allograft and using tumor endoprostheses (megaprostheses) helped orthopedic surgeons as well as patients in the sparing of limbs. Several types of megaprostheses have been described in the literature for oncological indications with unpredictable outcomes and complication rates. We review single-centered experience of three nononcological cases to assess the safety of using megaprostheses in patients with severe bone loss without malignant disease. In addition, a literature review on the previous use of megaprostheses as treatment modality, their outcome, and complications was done until August 2022. All the participants were found to be good candidates for megaprostheses implants after their refusal of amputation. Their infections were eradicated before the implants, and also, the range of movement and improvements are satisfactory. In addition, according to the literature compared to the alternative of amputation, this operation has proven to be life-altering and revolutionary for many patients. We believe that megaprostheses might be a good limb salvage alternative in patients with significant bone loss and massive skeletal deformities, even in nononcological situations. Future studies should focus on ways to improve the material and design of the megaprostheses and study the long-term complications and survival rate of the implants.

Elective hinge and polyethylene exchange for lower limb tumor endoprostheses: Is it a good idea?

Elective hinge and polyethylene exchange for lower limb tumor endoprostheses: Is it a good idea?

Proximal Femur Salvage in Revision Knee Arthroplasty Due to Oncologic Indications: Long-term Results of Onlay and Overlapping Allograft in Revision Surgeries.

Mechanical failures of tumor endoprosthesis in the distal femur usually require revision surgery. We investigated if the proximal femur host bone can be salvaged by onlay and overlapping allograft in revision surgeries due to aseptic loosening and stem fractures. We retrospectively reviewed 18 patients (7 men and 11 women) with osteosarcoma around the knee. The entire cohort was classified into three subgroups (no bone graft: 6, onlay allograft: 7, and overlapping allograft: 5) according to our treatment strategy. The median interval from the initial surgery to the revision was 94.5 months (range, 21-219 months), and the median follow-up period from the revision surgery was 88.0 months (range, 24-179 months). At the last follow-up, 9 of the 18 patients maintained their endoprostheses, and the 5-year prosthesis survival rate was 57.9%. Limb survival was 100%. Five-year prosthesis survival rate was 66.7% in the no bone graft group, 85.7% in the onlay allograft group while 30.0% in the overlapping allograft group. In the no bone graft group and onlay allograft group, 66.7% (4/6) and 57.1% (4/7) maintained their revision prostheses while no prostheses survived in the overlapping allograft group. Recurrent stem loosening was observed in 14.2% (1/7) and 60.0% (3/5) of the onlay allograft and overlapping allograft groups, respectively, despite allograft bone union. The complication rate was 66.7% (12/18) in the entire cohort. The most common type of complication was infection (n = 6), followed by aseptic loosening (n = 4) and mechanical failure (n = 2). This study indicates that onlay allograft can be used as a supportive method in revising failed endoprosthesis if the extent of host bone destruction is extensive. However, applying overlapping allograft to secure bone stock showed a high rate of mechanical failures and infection in the long term. Future studies with a larger cohort are necessary to assess the prognostic factors for the higher complication rate in overlapping allograft and the need for overlapping allograft. Surveillance with consideration of the risk of anteromedial osteolysis in allograft and efforts for prevention of periprosthetic infection are essential.

Primary fibrosarcoma of the distal femur. Report of a rare case

Fibrosarcoma of bone is a relatively rare malignant neoplasia, representing less than 5% of all bone tumors. It is distinguished from other bone sarcomas by the presence of spindle-shaped tumor cells located among intertwining bundles of collagen fibers, without any other type of histological differentiation, such as the formation of cartilage or bone.&#x0D; In the present report, we present a rare case of primary fibrosarcoma in the distal femur in a 45-year-old patient with complaints of mild pain and swelling in the right knee joint for approximately 6 months. After imaging evaluation, a biopsy was performed; in the second stage, a subsequent resection of 16 cm of the distal femur and its replacement with a tumor endoprosthesis was performed. Three months postoperatively, no local recurrence or metastasis of the tumor was observed.

Femoral Discrepancy After Childhood Bone Sarcoma Surgery Can Be Treated With Magnetic Intramedullary Nails.

This study aims to determine whether femoral lengthening with a magnetic motorized intramedullary nail (PRECICE; NuVasive) is safe and effective in patients with discrepancy due to limb salvage performed for bone sarcomas before skeletal maturity. Six patients (male, 4; female, 2) with a mean age of 9.3 years (range, 4.8-12.8 years) at the time of index limb salvage surgery were retrospectively analyzed. Four patients had undergone biological reconstruction with liquid-nitrogen recycled frozen autograft shell and inlaid vascular fibula combination and 2 had undergone nonbiological reconstruction with distal femur modular tumor endoprosthesis. The mean age at PRECICE operation was 16.1 years (range, 13.4-20.1 years). The mean prelengthening femoral discrepancy was measured as 60 mm (range, 39-80 mm). Lengthening was achieved in 5 of these 6 patients. Although the PRECICE nail was successfully implanted in the sixth patient, lengthening could never be performed owing to failure to overcome the chronic diaphyseal nonunion first, as intended with compressive use of the nail. For the other 5 patients, in whom lengthening was performed, the mean lengthening was 45 mm (range, 35-52 mm), the mean ratio of achieved to planned lengthening was 93% (range, 74%-100%), and the mean bone-healing index was 41 days per cm (range, 24-69 days per cm). Mean Musculoskeletal Tumor Society score improved from 25.6 to 27.2 after lengthening. No major complications occurred. The outcomes of this study demonstrate that the PRECICE implant can safely and effectively correct femoral length discrepancy caused by limb salvage performed for osteosarcoma before skeletal maturity. [Orthopedics. 2023;46(1):27-34.].

Classification and reconstruction of femoral bone defect in the revision of aseptic loosening of distal femoral endoprostheses: a 10-year multicenter retrospective analysis

ObjectiveThis study proposes a system for classifying the aseptic loosening of distal femoral endoprostheses and discusses reconstruction methods for revision surgery, based on different classification types.MethodsWe retrospectively analyzed the data of patients who received revision surgery for aseptic loosening in distal femoral tumor endoprosthesis from January 2008 to December 2020 at 3 bone tumor treatment centers in China. Based on the patient imaging data, we proposed a classification system for the aseptic loosening of distal femoral endoprostheses and discussed its revision surgery strategy for various bone defects.ResultsA total of 31 patients were included in this study, including 21 males and 10 females aged 15–75 y (average: 44.3 y). First-revision surgery was performed on 24 patients, whereas second-revision surgery was conducted on 7 patients. The 31 patients were classified into different types based on the degree of aseptic loosening: Type I, 12 patients (38.7%); Type IIa, 7 patients (22.5%); Type IIb, 7 patients (22.5%); Type III, 4 patient (12.9%); and Type IV, 1 patient (3.2%). For type I, 11 patients underwent revisions with standard longer-stem prostheses (one with the original prosthesis), and one patient had the original prosthesis plus cortical allograft strut. For type II (a and b), 10 patients underwent revisions with original prosthesis or longer-stem prosthesis and 4 patients combined with cortical allograft strut. For type III, one patient underwent revision with a longer-stem prosthesis and the other 3 patients with a custom short-stem prosthesis. For type IV, only one patient underwent revision with a custom short-stem prosthesis.ConclusionsAseptic loosening of the distal femoral prosthesis can be divided into 4 types: type I, type II (a, b), type III and type IV. The reconstruction methods of our centers for different types of bone defects can offer some reference value in the revision of aseptic loosening.

Intermediate-term results and risk factors analysis of tumor endoprosthesis in paediatric patients after the resection of lower extremity bone sarcoma.

Mechanical failure of the endoprostheses is a concern in paediatric patients with primary bone sarcoma. Their long-term results are variable in the Asian population, thus we aim to investigate the outcome by assessing the mechanical failure, its risk factors and the functional results. We retrospectively reviewed 38 paediatric patients (mean 13.29, range 6-18) with primary bone sarcoma of lower extremity undergone chemotherapy and limb salvage surgery with tumor endoprosthesis between 2003 and 2016. All hospital notes were reviewed for any type of failures. Risk factors for implant loosening like stem size, remaining bone length, stem length, extracortical bone bridge ingrowth (EBBI), the ratio of resected bone length to whole bone length, bone stem ratio and custom-made versus modular were analyzed. The limb function was recorded by Musculoskeletal Tumor Society (MSTS) score. Median follow-up time was 7.42years (3.0-15.4years) and minimum follow-up for surviving patients was 2years. Endoprosthesis survivorship, according to Kaplan Meier was 94.7%, 85.4% and 66.2% at 2, 5 and 10years respectively. Type II failure occurred in three patients (7.9%). Type III failure occurred in four patients (10.5%). Type IV failure occured in two patients (5.2%). Only EBBI independently predicted implant loosening (p = .007). Risk factors like stem size, remaining bone length, stem length, the ratio of resected bone length to whole bone length and custom-made versus modular were not associated with increase in implant loosening (p > .05). The mean stem size was 9.41mm in asymptomatic group, comparable with 9.22mm in the failure group (p = .79). The MSTS score was 29.62. Our data suggests that paediatric Chinese patients with small body built had good and excellent mid-term results in implant survival and limb function respectively. EBBI is important in preventing loosening in tumor endoprosthesis. In contrast to the reported higher failure risk with stem size <12mm, we found no increased loosening rate with smaller stem size endoprosthesis. Class III.

MUTARS® Humero pro Femur replacement: A novel reconstructive procedure after malignant bone tumor resection of the femur in young children

Limb-preserving surgery in young children suffering malignant bone tumor of the femur is challenging due to the specific anatomical conditions. Extendable tumor endoprostheses are often oversized, while custom-made endoprostheses do not provide the intraoperatively required variability regarding reconstruction length. Allo- and autograft replacements, on the other hand, show high complication and revision rates. We report a novel reconstructive procedure after resection of malignant bone tumors of the femur in young children, and present our preliminary results of this technique.

Extensor mechanism reconstruction and joint preservation surgery following a tibial tuberosity fracture in giant cell tumor of bone: A case report.

Introduction and importancePathologic fractures of the tibial tuberosity secondary to giant cell tumor of bone are rare injuries. While there are several well-described methods in the literature to reattach the tibial tuberosity, these techniques rely on good quality bone. However, in the presence of diseased and weak bone, additional factors have to be considered.Case presentationA 47-year-old man with a Giant Cell Tumor of bone affecting the proximal tibia presented with a displaced avulsion fracture of the tibial tuberosity. The patient underwent surgical curettage, bone grafting and osteosynthesis with reattachment of the tibial tuberosity. Eighteen months after surgery there is no evidence of tumor recurrence, and despite mild knee pain and a limited range of movement, the patient has returned to work.Clinical discussionThe extensor mechanism was repaired by first reinforcing the tuberosity fragment with an autograft before reattaching it using a tension band FibreWire ® suture. Without access to a tumor endoprosthesis we used a joint sparing approach to treat the Giant Cell Tumor.ConclusionPatients with dual-pathology present technical challenges in repairing the extensor mechanism and treating the underlying condition. Surgeons must address competing priorities in a holistic, patient-centred approach consistent with their working environment.