Endoprosthetic Reconstruction of the Proximal Humerus with an Inverse Tumor Prosthesis.

Reconstructing the proximal humerus after tumor removal is challenging due to muscle and bone loss. The current methods often result in poor shoulder function. This study assessed the long-term functional and oncological outcomes of using an inverse proximal humerus prosthesis in 46 patients with bone tumors. The results showed a mean range of motion of 62° in anteversion, 28° in retroversion, and 55° in abduction. Notably, 23 patients achieved over 90° of shoulder abduction, with an average of 140°. The median Musculoskeletal Tumor Society Score was 25. Complications included infection in two radiotherapy patients and single dislocations in seven patients. One patient with recurrent dislocations needed revision surgery. In conclusion, the use of the inverse proximal humerus prosthesis in bone tumor treatment yields excellent shoulder function and high patient satisfaction. This approach is especially beneficial for those with metastatic disease.

Treatment of Bifocal Periprosthetic Fractures above and below a Knee after Tumor using Spanning Ilizarov Device: A Case Report.

Introduction: Multiple treatment options and internal and external devices have been recommended for periprosthetic fractures management around total knee arthroplasty. Case Report: We present the case of the high-energy bifocal periprosthetic fractures of the femur and the tibia after total knee prosthesis following excision of a tumor. One of the fractures was an open tibial fracture Gustilo Type IIIB and the other - comminuted subtrochanteric fracture of the femur with extrusion of periprosthetic cement pieces out from the bone defect. The Ilizarov circular external fixator was used for the skeletal stabilization and early functional treatment in this compound case. Conclusion: The use of Ilizarov external fixator for patients with complex periprosthetic fractures, who present severe technical difficulties in bone stabilization, especially by concomitant severe soft-tissue damage after high-energy injuries, is a good surgical alternative.

Risk Factors and Management of Prosthetic Joint Infections in Megaprostheses-A Review of the Literature.

Prosthetic joint infection (PJI) is the most common mode of failure of megaprostheses, yet the literature on the topic is scarce, and studies report conflicting data regarding the optimal treatment strategy. Patients with megaprostheses PJI are often immunosuppressed, and surgeons must balance the trade-off between treatment efficacy and morbidity associated with the surgery aiming for infection eradication. Our review on megaprostheses PJI focuses on two axes: (1) risk factors and preventative strategies; and (2) surgical strategies to manage this condition. Risk factors were classified as either unmodifiable or modifiable. Attempts to decrease the risk of PJI should target the latter group. Strategies to prevent PJI include the use of silver-coated implants, timely discontinuation of perioperative antibiotic prophylaxis, and adequate soft tissue coverage to diminish the amount of dead space. Regarding surgical treatment, main strategies include debridement, antibiotics, implant retention (DAIR), DAIR with modular component exchange, stem retention (DAIR plus), one-stage, and two-stage revision. Two-stage revision is the "gold standard" for PJI in conventional implants; however, its success hinges on adequate soft tissue coverage and willingness of patients to tolerate a spacer for a minimum of 6 weeks. DAIR plus and one-stage revisions may be appropriate for a select group of patients who cannot endure the morbidity of two surgeries. Moreover, whenever DAIR is considered, exchange of the modular components should be performed (DAIR plus). Due to the low volume of megaprostheses implanted, studies assessing PJI should be conducted in a multi-institutional fashion. This would allow for more meaningful comparison of groups, with sufficient statistical power. Level of evidence: IV.

Nickel-titanium shape memory alloy embracing fixator benefits the determination of the implantation angle of prosthesis stem in tumor-type artificial joint replacement.

BACKGROUND: Hip tumors often require tumor-type artificial joint replacement. The selection of the prosthesis stem (hip tumor prosthesis stem) implantation angle during the operation is important to prevent the complication of postoperative prosthesis dislocation. The aim of this study was to evaluate the role of a nickel-titanium (Ni-Ti) shape memory alloy embracing fixator in determination of the implantation angle of a hip tumor prosthesis stem and analyze its efficacy. METHODS: 36 patients with proximal femur tumor were treated with extended tumor resection and prosthetic replacement. 14 patients received prosthetic replacements with the embracing fixators fixing between the junction of the prosthesis stem and the femur temporarily, while the other 22 patients received the same replacements but without the fixators. The two groups were compared regarding occurrence of complications, limb function, and active hip range of motion (ROM). RESULTS: There was no case of hip dislocation in the group that received prosthetic replacements with the use of embracing fixators. Occurrence of deep infection had no difference between the two groups. However, better limb function and higher active (ROM) on abduction or flexion were observed in the group using embracing fixators. CONCLUSION: Ni-Ti shape memory alloy embracing fixator plays a key role in assisting the accurate implantation angle of the prosthesis stem in prosthetic replacement. The prosthesis stem can be adjusted to the optimal angle with the help of the embracing fixator. Patients have a lower risk of dislocation, better limb function, and higher active hip ROM.

The Use of Tumor Prostheses for Primary or Revision Reverse Total Shoulder Arthroplasty With Proximal Humeral Bone Loss.

Background: During shoulder arthroplasty with substantial bone and soft tissue loss, reverse shoulder arthroplasty (RSA) with a tumor prosthesis may restore function, reduce pain, and improve implant fixation. Methods: Thirteen adult patients undergoing RSA using a tumor prosthesis system were retrospectively reviewed. Preoperative visual analog score (VAS), single assessment numeric evaluation (SANE), American Shoulder and Elbow Surgeons (ASES) score, simple shoulder test (SST), and forward flexion were compared to latest follow up. Postoperative radiographs and complications were recorded. Results: Mean age at surgery was 68.4 years. Eight patients had undergone at least 1 prior operation on the indicated shoulder. Six patients required wide excision of proximal humerus tumor. At mean of 34 months postoperatively, significant improvements were noted in VAS (P = .03) and ASES score (P = .04). Active forward elevation was 81.1 degrees. For all patients, postoperative radiographs demonstrated satisfactory alignment. Complications occurred in 38% of patients, with 31% requiring reoperation. Conclusion: In cases of failed shoulder arthroplasty with excessive bone and soft tissue loss or substantial tumor burden, RSA with a tumor prosthesis can reduce pain levels and improve functional outcomes. However, forward elevation remains limited, and postoperative complications are a concern.

Long-term outcome of patients with primary or secondary tumors of the proximal femur treated by bipolar modular tumor prosthesis.

PURPOSE: The proximal femur is a common area for primary and also metastatic bone tumors. The objective of this study was to assess the long-term functional and oncological outcomes of patients with malignant primary or secondary tumors of the proximal femur, who underwent proximal femoral resection then reconstruction using bipolar modular tumor prosthesis. METHODS: Sixty patients with proximal femoral malignant tumors underwent resection and bipolar modular prosthesis between 2000 and 2016, were retrospectively reviewed. Based on diagnosis and presence or absence of pathological fracture, patients were divided into groups. The functional outcome of the patients was evaluated using the Musculoskeletal Tumor Society (MSTS) functional scoring system for the lower extremities. RESULTS: The mean age was 38 (9-80) years at the time of primary surgery. Pathological fracture was the presentation in 28 patients. The study included 44 patients with primary bone tumor and 16 patients with a secondary bone tumor. The mean MSTS functional score of the patients was 24.3 (range, 18-30) points with no significant difference in patients with primary or secondary tumors. The rate of complications in the present series was 45%. The most frequent complication was an infection in 10 patients (16.7%), followed by aseptic loosening in 7 patients (11.7%). Local recurrence of primary bone tumors occurred in three out of 44 patients (6.8%). CONCLUSION: Modular bipolar tumor prosthesis has a good long-term functional result in both primary and secondary tumors of the proximal femur, with no significant effect of age, presence or absence of pathological fracture or femoral resection length on the functional outcome. It was found that the only statistically significant variable regarding the risk of infection is previous surgeries. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Revision for Aseptic Loosening of Tumor Prosthesis in Lower Limbs / 肿瘤防治研究

Objective To determine the prosthesis survival and limb function after revision of global modular replacement system (GMRS) tumor prosthesis. Methods We retrospectively analyzed the clinical data of 16 patients who developed aseptic loosening of lower extremity tumor prosthesis and subsequently received revision with GMRS from 2009 to 2012. Kaplan-Meier method was used to calculate the 5- and 8-year survival rates of the prosthesis. The MSTS function scale was used to evaluate the functional outcomes. Results The average follow-up time was 90 months (52-118 months). The 5- and 8-year survival rates of GMRS prosthesis were both 94%. After revision, two patients failed, including one case of infection and one case of repeated aseptic loosening. The average interval between the first joint replacement and revision surgery was 81 months (27-187 months). Until the last follow-up, 93.3%(14/15) of the patients did not develop repeated aseptic loosening, 85.7%(12/14) of the patients who underwent GMRS revision had a longer loosening-free survival than those with the primary joint replacement (90.6±19.3 vs. 43.4±29.7 months, P=0.001). The average MSTS functional score was 27.7(24-30). Conclusion The incidence of repeated aseptic loosening for GMRS prosthesis is low and the limb function is good. The reported technique is satisfactory in the middle and long term.

Reduction of metal artifacts from knee tumor prostheses on CT images: value of the single energy metal artifact reduction (SEMAR) algorithm.

BACKGROUND: To evaluate the effect of the single energy metal artifact reduction (SEMAR) algorithm with a multidetector CT (MDCT) for knee tumor prostheses. METHODS: First, a phantom of knee tumor prosthesis underwent a MDCT scan. The raw data was reconstructed by iterative reconstruction (IR) alone and IR plus SEMAR. The mean value of the CT number and the image noise were measured around the prosthesis at the stem level and articular level. Second, 95 consecutive patients with knee tumor prostheses underwent MDCT scans. The raw data were also reconstructed by the two methods. Periprosthetic structures were selected at the similar two levels. Four radiologists visually graded the image quality on a scale from 0 to 5. Additionally, the readers also assessed the presence of prosthetic complication and tumor recurrence on a same scale. RESULTS: In the phantom, when the SEMAR was used, the CT numbers were closer to normal value and the noise of images using soft and sharper kernel were respectively reduced by up to 77.1% and 43.4% at the stem level, and by up to 82.2% and 64.5% at the articular level. The subjective scores increased 1 ~ 3 points and 1 ~ 4 points at the two levels, respectively. Prosthetic complications and tumor recurrence were diagnosed in 66 patients. And the SEMAR increased the diagnostic confidence of prosthetic complications and tumor recurrence (4 ~ 5 vs. 1 ~ 1.5). CONCLUSIONS: The SEMAR algorithm can significantly reduce the metal artifacts and increase diagnostic confidence of prosthetic complications and tumor recurrence in patients with knee tumor prostheses.

Clinical outcomes of endoprosthetic reconstruction for proximal femoral resection.

INTRODUCTION: The proximal femur is a common site for primary sarcomas and metastatic lesions. Although the early results of tumor prostheses are promising, the long-term results of reconstruction are unknown. The purpose of this study is to evaluate the prognostic factors affecting prosthesis survival and complications after proximal femoral resection and reconstruction. METHODS: We reviewed the results of 68 patients who underwent proximal femoral resection and reconstruction with a modular bipolar-type tumor prosthesis between 2005 and 2017. The mean follow-up was 55.6 months (range 6-172 months). There were 50 male and 18 female patients with a mean age of 41.5 years (range 11-80 years). Cumulative survival analysis was performed to analyze the risk factors of prosthesis survival. We also evaluated the complications after operation. RESULTS: Fourteen (21%) patients required further surgery at a mean 37 months post-operatively (range 5-125 months). There were three cases of infection (4%), six of local recurrence (9%), three of acetabular erosion (4%) and two of stem loosening (3%). The implant survival rates were 83.9% at 5 years and 59.8% at 10 years. Prosthesis survivals did not differ based on fixation method (P = 0.085), age (P = 0.329) or resection length (P = 0.61). Acetabular chondrolysis was identified in 18 (26%) patients and longer resection length (≥20 cm) showed a trend for risk of acetabular wear (P = 0.132). CONCLUSION: The results of proximal femoral resection and reconstruction with a modular bipolar-type prosthesis were found to be acceptable with infection and local recurrence as short-term complications and loosening and acetabular erosion as long-term complications.

Management of Large Segmental Bone Defects at the Knee With Intramedullary Stabilized Antibiotic Spacers During Two-Stage Treatment of Endoprosthetic Joint Infection.

BACKGROUND: Following debridement of infected prostheses that require reconstruction with an endoprosthetic replacement (EPR), instability related to segmental residual bone defects present a challenge in management with 2-stage reimplantation. METHODS: We retrospectively reviewed all patients treated for revision total joint or endoprosthetic infection at the knee from 1998 to 2018. At our institution, patients with skeletal defects >6 cm following explant of prosthesis and debridement (stage 1) were managed with intramedullary nail-stabilized antibiotic spacers. Following stage 1, antimicrobial therapy included 6 weeks of intravenous antibiotics and a minimum of 6 weeks of oral antibiotics. Following resolution of inflammatory markers and negative tissue cultures, reimplantation (stage 2) of an EPR was performed. RESULTS: Twenty-one patients at a mean age of 54 ± 21 years were treated for prosthetic joint infection at the knee. Polymicrobial growth was detected in 38% of cases, followed by coagulase-negative staphylococci (24%) and Staphylococcus aureus (19%). Mean residual skeletal defect after stage 1 treatment was 20 cm. Prosthetic joint infection eradication was achieved in 18 (86%) patients, with a mean Musculoskeletal Tumor Society score of 77% and mean knee range of motion of 100°. Patients with polymicrobial infections had a greater number of surgeries prior to infection (P = .024), and were more likely to require additional debridement prior to EPR (odds ratio 12.0, P = .048). CONCLUSION: Management of large segmental skeletal defects at the knee following explant using intramedullary stabilized antibiotic spacers maintain stability and result in high rates of limb salvage with conversion to an endoprosthesis.

Parameterizing a tumor humeral prosthesis and development of a set.

BACKGROUND: The reconstruction of the proximal humerus is possible from the resection of the tumor and the placement of a prosthesis. In some cases, they do not meet the anthropometric aspects of the patients. OBJECTIVE: To determine the parameters to size the components of a humeral prosthesis and the development of a set, using design software. METHOD: Forty patients were selected for prostheses, radiographs and CT scans were analyzed and statistical tests were applied to the measurements. RESULTS: The length of the tumors was 8-20 cm. The minimum length of the humerus was 28 cm and 33 cm the maximum. Correlation was observed between the humerus and the tumor and the height of the patient with p = 0.93088 and p = 0.904564, respectively; humerus diameter, p = 0.2345. The set will include three components, diameter 6-10 mm, and length of 24, 26 and 28 cm. Three modular spacers with lengths of 6, 8.5 and 13 cm. Crowns 6.5 and 8.5 cm long, 1.3 cm in diameter and 5 mm nut. CONCLUSION: With the development of the set, poorly calculated resections and adaptation to any humerus size can be resolved.

ANTECEDENTES: La reconstrucción del húmero proximal es posible a partir de la resección del tumor y la colocación de una prótesis. En algunos casos, las prótesis no cumplen con los aspectos antropométricos de los pacientes. OBJETIVO: Determinar los parámetros para dimensionar los componentes de una prótesis de húmero y el desarrollo de un set, mediante software de diseño. MÉTODO: Se seleccionaron 40 pacientes para prótesis, se analizaron radiografías y tomografías computarizadas, y se aplicaron pruebas estadísticas a las mediciones. RESULTADOS: La longitud de los tumores fue de 8-20 cm. La longitud mínima del húmero fue de 28 cm y la máxima fue de 33 cm. Se observó correlación entre el húmero y el tumor y la altura del paciente, con p = 0.93088 y p = 0.904564, respectivamente; para el diámetro del húmero, p = 0.2345. El set incluye tres componentes, con diámetro de 6-10 mm y longitud de 24, 26 y 28 cm; tres espaciadores modulares con longitudes de 6, 8,5 y 13 cm; coronas de 6,5 y 8,5 cm de largo, 1,3 cm de diámetro y tuerca de 5 mm. CONCLUSIÓN: Con el desarrollo del set se pueden resolver resecciones mal calculadas y la adaptación a cualquier tamaño de húmero.

Risk Factors of Periprosthetic Infection in Patients with Tumor Prostheses Following Resection for Musculoskeletal Tumor of the Lower Limb.

Tumor prostheses for the lower limb following resection of musculoskeletal tumors is useful limb salvage management; however, as compared with routine total joint replacement, an increased incidence of deep periprosthetic infection of tumor prosthesis has been observed. The risk factors for periprosthetic infection of tumor prosthesis remain unclear. This study examines the risk factors and outcomes of periprosthetic infection. This was a retrospective observational study including 121 patients (67 males and 54 females) who underwent tumor prosthesis of the lower limb after resection of musculoskeletal tumors between 1 January 2000 and 30 November 2018. Among a total of 121 tumor prostheses, 7 were total femurs, 47 were proximal femurs, 47 were distal femurs, and 20 were proximal tibias. The incidence of postoperative infection and its risk factors were analyzed. Forty-five patients (37%) had osteosarcoma, 36 patients (30%) had bone metastasis, and 10 patients (8%) had soft-tissue tumors invading the bone. The mean operating time was 229 min, and the mean follow-up duration was 5.9 years. Deep periprosthetic infection was noted in 14 patients (12%). In the multivariate analysis, the risk factors for postoperative infection were identified as being male (hazard ratio [HR], 11.2316; p = 0.0100), soft-tissue tumor (HR, 52.2443; p = 0.0003), long operation (HR, 1.0056; p = 0.0184), and radiotherapy (HR, 6.5683; p = 0.0476). The incidence of periprosthetic infection in our institution was similar to that of previous reports. Patients undergoing tumor prosthesis of the lower limb who were male, had a soft-tissue tumor, were predicted to have a long operation, and who underwent radiation, had an increased possibility of postoperative infection.

Reverse shoulder-allograft prosthesis composite, with or without tendon transfer, for the treatment of severe proximal humeral bone loss.

BACKGROUND: The treatment of severe proximal humeral bone loss (PHBL) secondary to tumor resection or failed arthroplasty is challenging. We evaluated the outcomes and complications of reconstruction with reverse shoulder-allograft prosthesis composite (RS-APC), performed with or without tendon transfer. METHODS: An RS-APC procedure was performed in 25 consecutive patients with severe PHBL (>4 cm): 12 after failed reverse shoulder arthroplasty, 5 after failed hemiarthroplasty for fracture, 6 after failed mega-tumor prosthesis placement, and 2 after tumor resection. The median length of humeral bone loss or resection was 8 cm (range, 5-23 cm). Humeral bone graft fixation was obtained with a long monobloc reverse stem and a "mirror step-cut osteotomy," without plate fixation. Nine infected shoulders underwent a 2-stage operation with a temporary cement spacer. In addition, 9 patients (36%) underwent an associated L'Episcopo procedure. The median follow-up duration was 4 years (range, 2-11 years). RESULTS: Overall, 76% of patients (19 of 25) were satisfied. In 8 patients (32%), a reoperation was needed. At last follow-up, we observed incorporation at the allograft-host junction in 96% of the cases (24/25); partial graft resorption occurred in 3 cases and severe in 1. The median adjusted Constant score was 53% (range 18-105); Subjective Shoulder Value, 50% (range 10%-95%). Additional tendon transfers significantly improved active external rotation (20° vs. 0°, P < .001) and forward elevation (140° vs. 90°, P = .045). CONCLUSIONS: (1) Shoulder reconstruction with RS-APC provides acceptable shoulder function and high rates of graft survival and healing. (2) Additional L'Episcopo tendon transfer (when technically possible) improves active shoulder motion. (3) The use of a long monobloc (cemented or uncemented) humeral reverse stem with mirror step-cut osteotomy provides a high rate of graft-host healing, as well as a limited rate of graft resorption, and precludes the need for additional plate fixation. (4) Although rewarding, this reconstructive surgery is complex with a high risk of complications and reoperations. The main advantages of using an allograft with a reverse shoulder arthroplasty (compared with other reconstruction options) are that this type of reconstruction (1) allows restoration of the bone stock, thus improving prosthesis fixation and stability, and (2) gives the possibility to perform a tendon transfer by fixing the tendons on the bone graft to improve shoulder motion.

Predictive Value of the Nomogram Model in Patients With Megaprosthetic Failure Around the Knee: A Retrospective Analysis.

BACKGROUND: Megaprosthetic replacement is one of the main methods for reconstructing mega bone defects after tumor resection. However, the incidences of complication associated with tumor prostheses were 5-10 times higher than that of conventional total knee arthroplasty. The objective of this study is to establish and validate a nomogram model which can assist doctors and patients in predicting the prosthetic survival rates. METHODS: Data on cancer patients treated with tumor prosthesis replacements at our institution from November 2001 to November 2017 were collected. The potential risk factors which were well-studied and shown to be associated with megaprosthetic failure were analyzed. A nomogram model was established using independent risk factors screened out by multivariate regression analysis. The concordance index and calibration curve were selected for internal validation of the predictive accuracy of nomogram. RESULTS: The 3-, 5-, 10-, and 15-year prosthetic survival rates were 92.8%, 88.6%, 74.1%, and 48.3%, respectively. The prosthetic motion mode, body mass index, type of reconstruction, type of prosthesis, and length of bone resection were independent risk factors for tumor prosthetic failure. A nomogram model was established using these significant predictors, with a concordance index of 0.77 and a favorable consistency between predicted and actual prosthetic failure rate according to the internal validation, indicating that the nomogram model had acceptable predictive accuracy. CONCLUSION: The prediction model identifies high-risk patients for whom attached preventive measures are required. Future studies regarding reduction in incidence of prosthetic failure should attach importance to these high-risk patients.

Midterm Success of a Custom, Non-Fluted, Diaphyseal, Press-Fit Stem Used With a Tumor Megaprosthesis System.

BACKGROUND: High rates of aseptic loosening with cemented prostheses have led to increased utilization of uncemented stems in the setting of megaprosthetic reconstruction. Theoretic concerns of rotational instability resulted in early stem designs with de-rotational mechanisms such as flutes or side plates. However, these designs have their own associated complications, and mechanical data suggest they are unnecessary. The purpose of this study is to evaluate outcomes and survivorship of an unfluted diaphyseal press-fit stem in the setting of megaprosthetic reconstruction. METHODS: Forty-five patients (46 stems), with a minimum 3-year follow-up, underwent reconstruction using 1 of 2 fully porous coated, unfluted, press-fit stems between 2005 and 2013: revision stem with adapter to the megaprosthesis (revision stem), or custom megaprosthesis stem (custom stem). Complications were described using the Henderson classification system, and subanalyses evaluated stem-related failures and survival. Radiographic evaluation of stem fixation was determined via evidence of bone bridging, spot welding, resorption, subsidence, and pedestal formation. Four patients had early stem removal for local recurrence or infection and were thus excluded from the radiographic analyses. RESULTS: Twenty-eight femoral (15 revision stem, 13 custom stem) and 14 tibial (6 revision stem, 8 custom stem) stems were reviewed. Average follow-up was 81 months (range, 42-140 months). Revision for implant-related complications occurred in 7 of 41 (17%), all in revision stems (3 adapter failures, 4 polyethylene wear). At final follow-up, all stems were retained without evidence of aseptic loosening, although 7 of 41 (17%) exhibited mild stress shielding. CONCLUSION: A non-fluted, press-fit stem used with a tumor prosthesis provided a stable bone-prosthesis interface at midterm follow-up.

Establishment and validation of a nomogram model for aseptic loosening after tumor prosthetic replacement around the knee: a retrospective analysis.

BACKGROUND: Aseptic loosening has become the main cause of prosthetic failure in medium- to long-term follow-up. The objective of this study was to establish and validate a nomogram model for aseptic loosening after tumor prosthetic replacement around knee. METHODS: We collected data on patients who underwent tumor prosthetic replacements. The following risk factors were analyzed: tumor site, stem length, resection length, prosthetic motion mode, sex, age, extra-cortical grafting, custom or modular, stem diameter, stem material, tumor type, activity intensity, and BMI. We used univariate and multivariate Cox regression for analysis. Finally, the significant risk factors were used to establish the nomogram model. RESULTS: The stem length, resection length, tumor site, and prosthetic motion mode showed a tendency to be related to aseptic loosening, according to the univariate analysis. Multivariate analysis showed that the tumor site, stem length, and prosthetic motion mode were independent risk factors. The internal validation indicated that the nomogram model had acceptable predictive accuracy. CONCLUSIONS: A nomogram model was developed for predicting the prosthetic survival rate without aseptic loosening. Patients with distal femoral tumors and those who are applied with fixed hinge and short-stem prostheses are more likely to be exposed to aseptic loosening.

Comparative Analysis of Early Follow-up of Biologic Fixation and Cemented Stem Fixation for Femoral Tumor Prosthesis.

OBJECTIVE: To compare the safety and efficacy between biologic fixation and traditional cement stems for the fixation of distal femoral prostheses for reconstruction following tumor resection. METHODS: Retrospective analysis was performed of patients who received a first distal femoral tumor prosthesis, with a rotating hinge, in the Department of Orthopaedic Oncology of Beijing Jishuitan Hospital between October 2011 and January 2016. Two hundred and sixty eligible cases were enrolled, with a cemented fixation used in 199 of these cases and a biologic fixation in 61 cases. Survival rates and survival time of prostheses were analyzed, with prosthetic failure considered as the endpoint event for survival time of the prosthesis. Kaplan-Meier survival curve and the log-rank test were used to compare survival rates between the two types of fixation methods, and factors that may affect the survival rate of prosthesis were evaluated. RESULTS: Of the 260 cases forming our study group, 138 were males and 122 females, with 102 males and 97 females in the cemented fixation group (mean age, 25.8 years; range, 8-72 years) and 36 males and 25 females in the biologic fixation group (mean age, 25.5 years; range, 12-59 years). Osteosarcoma was the most common type of tumor (188 cases, 72.3%), of which 145 cases (72.9%) were in the cemented and 45 cases (72.1%) in the biologic fixation group. Among the 260 cases enrolled into the study group, 13 patients were lost to follow-up. The average duration of follow-up for the remaining 247 cases was 28.8 months (median, 28.8 months; range, 4-61 months). The 3-year overall survival rate of prostheses was 87.2% for the biologic fixation group and 80.4% in the cemented fixation group (P = 0.389). The 3-year mechanical survival rate (excluding cases of infection and oncologic progression) was 100% for the biologic fixation and 97.6% for the cemented fixation group (P = 0.468). Complications were identified in 21 cases: 3 cases (5%) in the biologic and 18 cases (9.6%) in the cemented fixation group (P = 0.264). Two revisions were required in the cemented fixation group, but no revision was required in the biologic fixation group. A total of 10 patients required amputation after prosthesis implantation. Of these, 7 cases (4 cement and 3 biologic) were due to tumor recurrence; 3 cases were due to infection, with all cases occurring in the cement fixation group. CONCLUSION: The current study provides a baseline reference for future mid-term to long-term follow-up, laying the foundation for further studies and comparison of the incidence of aseptic loosening of both types of prosthesis.

Short Term Complications and Functional Results of Sarcoma Limb Salvage Surgeries.

BACKGROUND: Limb salvaging surgeries are current surgical treatment of extremity bone sarcomas. Resected bone replacement consists of two main methods; tumor prosthesis versus structural allograft. Biological reconstruction with an allograft is an economic cheap method in young sarcoma patients, however, the surgeons are more convinced with tumor prosthesis replacement. METHODS: We evaluated the short-term complications and functional results of 40 patients with aggressive extremity tumors in a retrospective cohort study. The mean age of cases was 25 and we followed them for 24 months. 17 patients underwent tumor prosthesis replacement after wide resection of limb sarcomas. 16 cases had structural allograft reconstruction and 7 patients treated with amputation. We matched confounders including age, sex, blood cell count and chemotherapy treatment in the study groups. RESULTS: We found 15 major complications (45.5%) in limb salvage surgeries composing infection, allograft nonunion, allograft fracture, prosthesis fracture, prosthesis loosening and device failure that needed another surgery to be resolved. We had 10 major complications in allograft group (62%) and 5 in tumor prosthesis group (29.4%). Although the rate of complications was higher in allograft group, it didn't statistically indicate strong correlation (Fisher's exact: 0.084). Mean Musculo-Skeletal tumor rating Scale (MSTS) score was 25.8(73.7%) and 22.3(63.7%) in allograft group and prosthesis cases respectively. MSTS score had a normal distribution in the different groups with no significant difference between them. CONCLUSION: Although complications were higher in the allograft group, allograft could be offered to bone sarcoma patients, whom are predicted to have short life expectancy.

Long-term results of the Global Modular Replacement System tumor prosthesis for reconstruction after limb-sparing bone resections in orthopedic oncologic conditions: Results from a national cohort.

BACKGROUND AND OBJECTIVES: We investigated implant revision, implant failure, and amputation risk after limb-sparing bone tumor surgery using the Global Modular Replacement System (GMRS) tumor prosthesis in patients suffering from bone sarcomas (BS), giant cell tumors (GCT), or metastatic bone disease (MBD). MATERIAL AND METHODS: A retrospective study of a nationwide consecutive cohort (n = 119, 47 [12-81] years, M/F = 65/54) having limb-sparing surgery and reconstruction using the GMRS tumor prosthesis due to bone tumors (BS/GCT/MBD = 70/8/41) from 2005 to 2013. Anatomical locations were as followed: distal femur (n = 49), proximal femur (n = 41), proximal tibia (n = 26), or total femur (n = 3). Kaplan-Meier survival analysis and competing risk analysis with death as a competing risk were used for statistical analysis. RESULTS: For BS and GCT patients, 5-year patient survival was 72% (95% confidence interval [CI]: 59-85%) and for MBD 33% (95% CI: 19-48%). Thirty-two patients underwent revision surgery (5-year revision incidence 14%; 95% CI: 8-21%). Twelve patients had revision of bone-anchored parts (implant failure) with a 5-year revision incidence 6% (95% CI: 2-10%). Ten amputations were performed due to local relapse (n = 9) or recurrent infections (n = 1) with a 5-year incidence of amputation: 8% (95% CI: 3-13%). CONCLUSIONS: We identified a low risk of revision and amputation when using the GMRS tumor prosthesis for limb-sparing bone tumor.

Intra-articular soft-tissue sarcoma of the knee: Is extra-articular resection and tumor endoprosthetic reconstruction the solution? A retrospective report on eight cases.

Intra-articular sarcoma of the knee joint is a very rare condition. Extra-articular resection and reconstruction with a tumor prosthesis is usually performed. This report describes the results with this rare surgical procedure. This retrospective study evaluated the clinical and functional results after extra-articular resection of the knee joint in eight patients with soft-tissue sarcomas of the knee that were reconstructed using a tumor endoprosthesis. Five of the eight patients (62.5%) ultimately had to undergo amputation, mainly due to periprosthetic infection. In addition, two patients experienced periprosthetic fractures. The mean Musculoskeletal Tumor Society score was 18 (range 10-22), as function was impaired due to a weak extensor mechanism. These results suggest that in patients with intraarticular soft-tissue sarcomas, limb salvage procedures with tumor prostheses after extra-articular resection are associated with very high complication rates. In most cases, long-term limb salvage was not possible. When limb salvage is successful, function is also poor due to a weak extensor mechanism in the knee joint. The indication for this procedure should therefore be considered critically.