Tumor Prosthesis Research Articles

Knee Arthroplasty for Ankylosis in a Patient with Severe Hemophilia A

Abstract Hemophilic arthropathy is a common complication of hemophilia A and can lead to chronic synovitis, joint damage, and eventually ankylosis. We present a case report of a 39-year-old male patient with a history of recurrent hemorrhages into the joints. He had a history of traumatic injury to both upper limbs and lower limbs. The patient was on bed rest for 6 months. Subsequently, he developed ankylosis of both elbows in 30° of flexion and ankylosis of the right (Right) knee in 40° of flexion with tricompartmental arthritis of the left knee joint. Radiologically, the left knee joint showed reduced joint space with tricompartmental arthritis. The patient was managed by the tumor prosthesis for the Rt knee. He was advised for management of the elbow joints for which he was not willing. Postoperatively, he was allowed knee range of motion exercises and walking with a walker for 4 weeks followed by a stick for 1 month. At 6-month follow-up, he was able to walk effortlessly without support. The Knee Society Score improved from 47 preoperatively to 75 at 6-month follow-up.

Postoperative challenges addressed through nursing care of patients receiving lower extremity tumor prosthesis

BackgroundPatients with primary Bone Sarcoma and Giant Cell Tumors in the lower extremities often require major surgery involving tumor prostheses. The postoperative course for this patient group can be complex and influenced by various factors and challenges that demand careful nursing care. This study aims to identify challenges related to the nursing care of individuals with primary bone tumors following surgery for tumor prostheses in the lower extremities.MethodsA retrospective cohort study of 15 patients treated at Rigshospitalet, Copenhagen, Denmark, between November 5. 2016, and April 1. 2020 was conducted by medical record review, focusing on challenges related to postoperative nursing care. All patients with the surgery code “Bone Excision” were identified within the surgery booking system and screened for eligibility.ResultsPatients experienced postoperative challenges such as severe pain, prolonged time to mobilization (mean: 4 days), and defecation (mean: 5 days). The mean length of stay at the Rigshospitalet was 13 days. Furthermore, eleven patients (73%) reported disrupted sleep and nausea.ConclusionPatients undergoing tumor prosthesis surgery in the lower extremities face considerable postoperative challenges that contribute to a prolonged hospital stay. These challenges, including severe pain, delayed mobilization, and gastrointestinal issues, significantly impact recovery. The findings highlight the urgent need for targeted nursing interventions to address these issues effectively. Enhanced pain management protocols, early mobilization strategies, and comprehensive postoperative care plans are essential to improve patient outcomes and reduce the length of hospital stays. Addressing these challenges through dedicated nursing care is crucial for optimizing the recovery process for patients receiving lower extremity tumor prostheses.

Finite-element analysis of different fixation types after Enneking II + III pelvic tumor resection

The current primary treatment approach for malignant pelvic tumors involves hemipelvic prosthesis reconstruction following tumor resection. In cases of Enneking type II + III pelvic tumors, the prosthesis necessitates fixation to the remaining iliac bone. Prevailing methods for prosthesis fixation include the saddle prosthesis, ice cream prosthesis, modular hemipelvic prosthesis, and personalized prosthetics using three-dimensional printing. To prevent failure of hemipelvic arthroplasty protheses, a novel fixation method was designed and finite element analysis was conducted. In clinical cases, the third and fourth sacral screws broke, a phenomenon also observed in the results of finite element analysis. Based on the original surgical model, designs were created for auxiliary dorsal iliac, auxiliary iliac bottom, auxiliary sacral screw, and auxiliary pubic ramus fixation. A nonlinear quasi-static finite element analysis was then performed under the maximum load of the gait cycle, and the results indicated that assisted sacral dorsal fixation significantly reduces stress on the sacral screws and relative micromotion exceeding 28 μm. The fixation of the pubic ramus further increased the initial stability of the prosthesis and its interface osseointegration ability. Therefore, for hemipelvic prostheses, incorporating pubic ramus support and iliac back fixation is advisable, as it provides new options for the application of hemipelvic tumor prostheses.

Can Periprosthetic Joint Infection of Tumor Prostheses Be Controlled With Debridement, Antibiotics, and Implant Retention?

Two-stage revision for periprosthetic joint infection (PJI) in patients who have undergone segmental replacement of the distal femur or proximal tibia after tumor resection can be associated with considerable morbidity, pain, and risk of complications because the procedure often results in removal of long, well-fixed stems from the diaphysis. A less-aggressive surgical approach, such as debridement, antibiotics, and implant retention (DAIR), may be attractive to patients and surgeons because of less morbidity, but the likelihood of eradicating infection in comparison to the traditional two-stage revision is not well established for oncology patients. Furthermore, the relative risk of subsequent amputation for DAIR versus two-stage revision has not been defined for this population. (1) How does DAIR compare with two-stage revision in terms of infection control for patients with distal femoral or proximal tibial segmental modular endoprostheses? (2) Is DAIR as an initial procedure associated with an increased risk of amputation compared with two-stage revision for infection? From the longitudinally maintained orthopaedic oncology surgical database at our institution, we identified 69 patients who had been treated for a clinical diagnosis of PJI at the knee between 1993 and 2015. We excluded 32% (22) of patients who did not meet at least one of the major criteria of the Musculoskeletal Infection Society (MSIS) for PJI, 3% (2) of patients who underwent immediate amputation, 3% (2) of patients who had a follow-up time of < 24 months, and 7% (5) of patients who did not have a primary tumor of the distal femur or proximal tibia. The study consisted of 38 patients, of whom eight underwent two-stage revision, 26 underwent DAIR, and four underwent extended DAIR (removal of all segmental components but with retention of stems and components fixed in bone) for their initial surgical procedure. To be considered free of infection, patients had to meet MSIS standards, including no positive cultures, drainage, or surgical debridement for a minimum of 2 years from the last operation. Factors associated with time-dependent risk of infection relapse, clearance, amputation, and patient survival were analyzed using Kaplan-Meier survivorship curves and the log-rank test to compare factors. Association of demographic and treatment factors was assessed using chi-square and Fisher exact tests. Continuous infection-free survival at 5 years was 16% (95% CI 2% to 29%) for patients undergoing DAIR compared with 75% (95% CI 45% to 100%) for patients undergoing two-stage revision (p = 0.006). The median (range) number of total surgical procedures was 3 per patient (1 to 10) for DAIR and 2 (2 to 5) for two-stage revision. Twenty-nine percent (11 of 38) of patients eventually underwent amputation. Survival without amputation was 69% (95% CI 51% to 86%) for DAIR compared with 88% (95% CI 65% to 100%) for two-stage revision at 5 years (p = 0.34). The cumulative proportion of patients achieving infection-free status (> 2 years continuously after last treatment) and limb preservation was 58% (95% CI 36% to 80%) for patients initially treated with DAIR versus 87% (95% CI 65% to 100%) for patients first treated with two-stage revision (p = 0.001). Infection control was better with two-stage revision than DAIR. The chance of eventual clearance of infection with limb preservation was better when two-stage revision was chosen as the initial treatment. However, the loss to follow-up in the two-stage revision group would likely make the true proportion of infection control lower than our estimate. Our experience would suggest that the process of infection eradication is a complex and difficult one. Most patients undergo multiple operations. Nearly one-third of patients eventually underwent amputation, and this was a serious risk for both groups. While we cannot strongly recommend one approach over the other based on our data, we would still consider the use of DAIR in patients who present with acute short duration of symptoms (< 3 weeks), no radiographic signs of erosion around fixed implants, and organisms other than Staphylococcus aureus. We would advocate the extended DAIR procedure with removal of all segmental or modular components, and we would caution patients that there is a high likelihood of needing further surgery. A prospective trial with strict adherence to indications may be needed to evaluate the relative merits of an extended DAIR procedure versus a two-stage revision. Level III, therapeutic study.

Risk factors for peri-megaprosthetic joint infections in tumor surgery: A systematic review.

Peri-megaprosthetic joint infections (PJI) in tumor surgery are complex and challenging complications that significantly impact the outcomes of the patients. The occurrence of PJI poses a substantial threat to the success of these operations. This review aims to identify and summarize the risk factors associated with PJI in tumor surgery with megaprosthetic reconstruction as well as to determine the overall risk of PJI in limb salvage surgery. A thorough examination of published literature, scrutinizing the incidence of PJI in tumor prostheses after limb salvage surgery was done. Research studies that documented the incidence of PJI in tumor patients who underwent limb salvage surgery, and explored the risk factors associated with the occurrence of PJI were deemed eligible. A total of 15 studies were included in the analysis and underwent comprehensive examination. After the exploration of key parameters, several significant risk factors for PJI concerning the type of implant coating, surgical site characteristics, patient demographics, and procedural factors were recorded. The findings underscore the need for a nuanced approach in managing tumor patients undergoing limb salvage surgery and megaprosthetic reconstruction, with emphasis on individualized risk assessments and individualized preventive strategies.

Clinical exploration of the international society of limb salvage classification of endoprosthetic failure using Henderson in the application of 3D-printed pelvic tumor prostheses.

The use of 3D-printed pelvic prosthesis for postoperative reconstruction after pelvic tumor resection has become one of the primary reconstruction methods the incidence of complications related to postoperative prosthesis reconstruction is high. Drawing on the failure of the type of bone tumor reconstruction in Henderson,the occurrence of postoperative complications was explored to take advantage of the design improvement of the 3D-printed prosthesis of subsequent pelvic tumors. The data for patients who underwent 3D-printed pelvic tumor prostheses in the Department of Bone and Soft Tissue Surgery at the Affiliated Cancer Hospital of Guangxi Medical University from January 2019 to October 2022 were collected and analyzed. The median follow-up time for all patients was 15.99 months (1.33-31.16 months). At the most recent follow-up,all patients were alive,with an average Musculoskeletal Tumor Society (MSTS) score of 21.46 (17 to 26 points). Local recurrence occurred in two cases (15.3%), metastasis in four cases (30.7%), and complications in 10 cases (76.9%). Early complications after surgery were primarily local wound fissure, deep tissue infection, and postoperative neuralgia. Later complications included loose dissolution of internal fixation, postoperative prosthetic dislocation, and postoperative gluteal middle muscle gait. 3D printing personalized design pelvic tumor prosthesis is an effective way to reconstruct, and designing pelvic 3D printed tumor prosthesis with the help of Henderson's bone tumor reconstruction failure concept may help bone tumor surgeons develop better pelvic tumor prosthesis.

Mechanical Effects of Different Femoral Stem Diameters of Distal Tumor Prosthesis on Femoral Cortex

Mechanical Effects of Different Femoral Stem Diameters of Distal Tumor Prosthesis on Femoral Cortex

Effect evaluation of denosumab combined with curettage and bone cement reconstruction in the treatment of recurrent giant cell tumor of bone around the knee joint.

Giant cell tumor of bone (GCTB) is a common primary bone tumor with latent malignant tendency. GCTB is prone to occur around the knee joint, and surgery is the major treatment method. There are relatively few reports on denosumab in the treatment of recurrent GCTB around the knee joint and postoperative function evaluation of patients. This research aimed to explore the appropriate surgical options for the treatment of recurrent GCTB around the knee joint.19 patients with recurrent GCTB around the knee joint, who were admitted to Hospital for 3 months following denosumab treatment from January 2016 to December 2019, were included as the research subjects. The prognosis was compared between patients treated with curettage combined with polymethylmethacrylate (PMMA) and those with extensive-resection replacement of tumor prosthesis (RTP). A deep learning model of Inception-v3 combined with a Faster region-based convolutional neural network (Faster-RCNN) was constructed to classify and identify X-ray images of patients. The Musculoskeletal Tumor Society (MSTS) score, short form-36 (SF-36) score, recurrence, and the rate of complications were also analyzed during the follow-up period.The results showed that the Inception-v3 model trained on the low-rank sparse loss function was obviously the best for X-ray image classification, and the classification and identification effect of the Faster-RCNN model was significantly better than that of the convolutional neural network (CNN), U-Net, and Fast region-based convolutional neural network (Fast-RCNN) models. During the follow-up period, the MSTS score in the PMMA group was significantly higher than that in the RTP group (p<0.05), while there was no significant difference in the SF-36 score, recurrence, and the rate of complications (p>0.05).The deep learning model could improve the classification and identification of the lesion location in the X-ray images of GCTB patients. Denosumab was an effective adjuvant for recurrent GCTB, and widely extensive-resection RTP could reduce the risk of local recurrence after denosumab treatment for recurrent GCTB.

Aseptic loosening of tumor prostheses in distal femur after revision surgery: a retrospective study

BackgroundTumor prostheses of the distal femur after revision surgery is associated with high rates of aseptic loosening, which has introduced great challenges to the survival of patients, but only a few studies have evaluated their X-ray imaging. The purpose of this study was to analyze the risk factors for recurrence of aseptic loosening and make recommendations to reduce the incidence of aseptic loosening after revision surgery of tumor prostheses in the distal femur.MethodA retrospective analysis was performed on 23 patients who had revision surgery for distal femur prostheses due to aseptic loosening between June 2002 and June 2021. They were divided into two groups based on the condition of the prostheses after revision surgery: loosening group (9 patients) and control group (14 patients). Following the initial replacement, the length and diameter of the prosthetic intramedullary stem were measured through the standard full-length anteroposterior X-ray imaging of both lower limbs. The osteotomy length, femoral length and diameter, femoral intramedullary stem diameter, hip-knee-ankle angle (HKAA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), and so on were measured as well. Following that, statistical analysis was performed.ResultsPatients in the loosening group had statistically significant differences in the ratio of prostheses length to femur length (71.89 ± 6.62) and the ratio of intramedullary stem diameter to femoral diameter (25.50 ± 6.90) (P < 0.05), when compared to the control group. The HKAA (175.58 ± 2.78), mLDFA (94.42 ± 2.57), and the deviation angle between the lower limb alignment and the tibial prostheses force line (2.23 ± 1.09) in the loosening group were significantly different from those in the control group (P < 0.05) on postoperative radiographs of the entire length of the lower limbs. The lowest score in intramedullary manubrium I indicated less osteolysis, while the highest score in intramedullary manubrium III indicated the most serious osteolysis, and the difference was statistically significant (P < 0.05).ConclusionsOur study suggests that the use of longer and thicker intramedullary stems can effectively decrease the occurrence of aseptic loosening. Additionally, it is important to avoid using the original prostheses and reconstruct the standard line of lower limb force to further reduce the incidence of aseptic loosening. It is crucial to closely monitor the distal segment of the intramedullary stem for osteolysis after surgery.

Evaluation of endoprosthetic reconstruction after distal femoral bone-tumor resection

Background Endoprosthetic reconstruction is considered a reliable reconstructive option after periarticular tumor resection as it provides component modularity, improved fixation, near-anatomic appearance, and good functional outcomes. This study aimed at evaluation of the outcomes of the cemented modular distal femoral tumor prosthesis after wide intra-articular resection of aggressive or malignant bone tumors. Patients and methods The mean age of the patients was 29.77 years. There were 12 males and six females. The final diagnosis was osteosarcoma in 13 patients, giant-cell tumor in three patients, and chondrosarcoma in two patients. All patients with osteosarcoma received neoadjuvant chemotherapy. Wide intra-articular tumor resection was done through the anteromedial approach of the femur with reconstruction by cemented modular endoprosthesis. Results One patient died with pulmonary metastasis. The 5-year cumulative patient-survival rate was 88.88% and 5-year cumulative implant-survival rate was 93.65%. Local recurrence occurred in one (5.5%) patient, while distant metastasis occurred in another. Both of those patients died and were consequently excluded from further statistical work. The mean functional score, the modified Musculoskeletal Tumor Society rating scale, was 73.7%. Complications occurred in five (27.7%) patients. One (5.5%) patient had had a deep infection with failure of reconstruction requiring two-staged revision. There were four cases of superficial wound infection that were successfully treated conservatively. There was no aseptic loosening, periprosthetic fracture or dislocation, soft-tissue problem, or vascular impairment in the operated limb till the final follow-up. Conclusion Modular prosthetic reconstruction after wide resection of aggressive and malignant bone tumors of distal femur offers satisfactory clinical and functional outcomes as it allows immediate postoperative stability, early mobilization, and rehabilitation, with reasonable complication rate. Level of evidence: IV case series.

Staged Management of Infection with Adjustable Spacers After Megaprosthesis Implantation in Primary Sarcoma Patients.

While periprosthetic joint infection has always been a significant concern for orthopaedic surgeons, the rate of infection is five to ten times higher after tumor prosthesis implantation. With the growing use of mega-implants, the number of these infections has also increased. We aimed to investigate the results of our patients with a primary malignant musculoskeletal tumor, who underwent two-stage revision surgery for an infected mega-prosthesis. We also presented the emerging complicatons and required soft tissue reconstruction procedures. The study included 32 primary bone and soft tissue sarcoma patients who underwent a two-stage revision procedure for infection. After a rigorous bone and soft tissue debridement procedure at the first stage, antibiotic-loaded bone cement was wrapped around a cloverleaf type intramedullary nail and inserted into the forming gap. After a minimum of 6 weeks of antibiotic therapy, depending on patients' clinical signs and serum infection markers, the reimplantation stage was undertaken. The mean oncologic follow-up period was 28 months (range 5-96 months). During this period, 11 patients died because of non-infection related causes, 12 patients were alive with their disease, whereas 9 patients were totally free of their oncologic condition. The infection was eradicated in all survivors except one patient, where a high-level transfemoral amputation became necessary. Periprosthetic infection after tumor proshesis implantation in cancer patients can be managed with same principles as conventional arthroplaty procedures, taking care that they are immunocompromised and vulnerable patients and their bone stock loss is significant which makes surgical options more challenging.

Infections of Tumor Prostheses: An Updated Review on Risk Factors, Microbiology, Diagnosis, and Treatment Strategies.

Several causes contribute to the high infection rate in tumor prostheses, including extensive tissue dissection and patients' immunosuppression due to the neoplastic disease. Most of these infections develop within the first 2 years following surgery with 70% of them occurring during the first year, while they are often associated with a low pathogen burden. The pathogenesis of infections in tumor prostheses is linked to bacteria developing in biofilms. Approximately half of them are caused by Staphylococcus spp., followed by Streptococcus spp., Enterococcus spp., and Enterobacteriaceae spp., while multiple pathogens may be isolated in up to 25% of the cases, with coagulase-negative Staphylococci (CoNS) and Enterococccus spp. being the most frequent pair. Although early detection and timely management are essential for complete resolution of these challenging infections, prompt diagnosis is problematic due to the highly varying clinical symptoms and the lack of specific preoperative and intraoperative diagnostic tests. Surgical management with one- or two-stage revision surgery is the mainstay for successful eradication of these infections. The recent advances in laboratory diagnostics and the development of biofilm-resistant prostheses over the past years have been areas of great interest, as research is now focused on prevention strategies. The aim of this study is to review and consolidate the current knowledge regarding the epidemiology, risk factors, microbiology, and diagnosis of infections of tumor prostheses, and to review the current concepts for their treatment and outcomes.

OUTCOMES OF 35 CUSTOM 3D-PRINTED TITANIUM ACETABULAR IMPLANTS IN REVISION ARTHROPLASTY

We present the indications and outcomes of a series of custom 3D printed titanium acetabular implants used over a 9 year period at our institution (Sydney, Australia), in the setting of revision total hip arthroplasty.Individualised image-based case planning with additive manufacturing of pelvic components was combined with screw fixation and off-the-shelf femoral components to treat patients presenting with failed hip arthroplasty involving acetabular bone loss. Retrospective chart review was performed on the practices of three contributing surgeons, with an initial search by item number of the Medicare Benefits Scheme linked to a case list maintained by the manufacturer. An analysis of indications, patient demographics and clinical outcome was performed.The cohort comprised 65.2% female with a median age of 70 years (interquartile range 61–77) and a median follow up of 32.9 months (IQR 13.1 - 49.7). The indications for surgery were infection (12.5%); aseptic loosening (78.1%) and fracture (9.4%), with 65.7% of cases undergoing previous revision hip arthroplasty. A tumour prosthesis was implanted into the proximal femur in 21.9% of cases. Complications were observed in 31.3% of cases, with four cases requiring revision procedures and no deaths reported in this series. Kaplan-Meier analysis of all-cause revision revealed an overall procedure survival of 88.7% at two years (95%confidence interval 69 - 96.2) and 83.8% (95%CI 62 - 93.7) at five years, with pelvic implant-specific survival of 98% (95%CI 86.6 - 99.7) at two and five year follow up.We conclude that an individualised planning approach for custom 3D printed titanium acetabular implants can provide high overall and implant-specific survival at up to five years follow up in complex cases of failed hip arthroplasty and acetabular bone loss.

Intralesional curettage and cementation of low-grade chondrosarcomas of the appendicular skeleton: Long-term results from a single center.

The purpose of this study was to investigate the results and complications in patients who had low-grade chondrosarcomas in the appendicular skeleton and were treated by intralesional curettage and cementation within the scope of 25 years of experience in a single center. Ninety-one patients (72 female and 19 male) were retrospectively analyzed. The median at the time of surgery was 43 (17-78) years, and the median follow-up was 102 (26-288) months. All patients were treated by intralesional curettage followed by cementation with high-viscosity bone cement (polymethylmethacrylate). Complications and local recurrence rates, as well as clinical outcome scores were recorded. Five patients (5.49%) developed local recurrence at an average of 6.6 (6-9) months postoperatively. Four were treated with local wide excision and reconstruction with tumor prosthesis. One patient received recurettage and cementation. Two recurred patients were dedifferentiated into grade II chondrosarcomas in the last intervention. No major postoperative complication was identified in the series. Patients achieved an average Musculoskeletal Tumor Society scoring system of 92.4% (standard deviation 5.2; range 80-100) in the sixth postoperative month. Musculoskeletal Tumor Society scores in the recurrent patients decreased from an average of 90% to 75.3% after the final intervention. Intralesional curettage and cementation seem safe and reliable techniques with low recurrence and complication rates in treating low-grade chondrosarcomas of the appendicular skeleton. Clinical, radiological, and pathological evaluations are mandatory before surgical intervention, and a multidisciplinary approach is crucial. A strict follow-up regimen in the early postoperative period is needed and strongly recommended to detect local recurrence. Level IV, Therapeutic Study.

What's New in Musculoskeletal Tumor Surgery.

What's New in Musculoskeletal Tumor Surgery.

Work ability and physical activity after major bone sarcoma resection and reconstruction with tumour prosthesis of the lower extremities. A cross-sectional study

Purpose The aim of this study was to evaluate work ability, activity limitations and physical activity in adults that had gone through major bone sarcoma resection and reconstruction surgery in hip and knee. Materials and methods Twenty patients, of 72 enrolled, and 20 controls were included in this cross-sectional study. Work Ability Index scores (general [0–10 points], physical and mental [1–5 points]), the Patient Specific Functional Scale (0–10 points), step counts and the International Physical Activity Questionnaire (IPAQ) were assessed. Adjusted and unadjusted general linear models were applied. Results The patients had a mean age of 43 (range, 20–71) years and were assessed 7 years (range, 2–12) after surgery (proximal femoral n = 9, distal femoral n = 7, proximal tibia n = 4). Compared with controls, patients had lower general work ability (mean difference [95%CI], −1.3 points [−2.1, −0.5]) and work ability in relation to physical demands at work (−1.4 points [−2.0, −0.8]). The patients reported higher severities of activity limitation (−6.7 points [−7.9, −5.4]). There were no between-group differences in step counts or IPAQ-scores. Conclusion Despite similar levels of physical activity, patients showed poorer work ability and severe activity limitation. Post-operative rehabilitation in patients of the working-age population should include assessments of work ability and activities important to the individual. IMPLICATIONS FOR REHABILITATION Adults that have gone through resection and reconstruction surgery following bone sarcoma in lower extremity show clinically relevant reductions in work ability and self-selected activities To tailor post-operative rehabilitation at short and long term, initial assessment and monitoring should include work ability and activities important to the individual patient.

Biomechanical Comparison Between Porous Ti6Al4V Block and Tumor Prosthesis UHMWPE Block for the Treatment of Distal Femur Bone Defects.

Purpose: The management of bone defects is a crucial content of total knee revision. This study compared the biomechanical performance of porous Ti6Al4V block and tumor prosthesis UHMWPE block in treating distal femoral bone defects. Methods: The finite element models of AORI type 3 distal femoral bone defect treated with porous Ti6Al4V block and UHMWPE block were established. Sensitivity analysis was performed to obtain the appropriate mesh size. The biomechanical performance of treatment methods in bone defects were evaluated according to the peak stress, the Von Mises stress distribution, and the average stresses of regions of interest under the condition of standing on one foot and flexion of the knee. Statistical analysis was conducted by independent samples t-test in SPSS (p < 0.05). Results: In the standing on one-foot state, the peak stress of the porous Ti6Al4V block was 12.42 MPa and that of the UHMWPE block was 19.97 MPa, which is close to its yield stress (21 MPa). Meanwhile, the stress distribution of the UHMWPE block was uneven. In the flexion state, the peak stress of the porous Ti6Al4V block was 16.28 MPa, while that of the UHMWPE block was 14.82 MPa. Compared with the porous Ti6Al4V block group, the average stress of the region of interest in UHMWPE block group was higher in the standing on one foot state and lower in the flexion state (p < 0.05). Conclusion: More uniform stress distribution was identified in the porous Ti6Al4V block application which could reserve more bone. On the contrary, uneven stress distribution and a larger high-stress concentration area were found in the UHMWPE block. Hence, the porous Ti6Al4V block is recommended for the treatment of AORI type 3 distal femoral bone defect.

Does Systemic Chemotherapy Influence Skeletal Growth of Young Osteosarcoma Patients as a Treatment-Related Late Adverse Effect?

The aim of this study was to investigate the influence of systemic chemotherapy on the skeletal growth of young osteosarcoma patients as a treatment-related late adverse effect. We reviewed the height data of 20 osteosarcoma patients (13 males and 7 females) aged ≤18 years. The average (±SD) age at diagnosis was 14.5 (±3.3) years. The average follow-up interval was 89.6 months. After wide resection of the affected bones, reconstruction with tumor prostheses and auto-bone grafting was carried out in 11 and 9 cases, respectively. Pearson’s correlation coefficient was calculated to evaluate the association between actual and predicted (using Paley’s multiplier method) heights. Z-scores were used to compare the initial and final heights with the Japanese national growth curve. Actual and predicted heights were correlated according to Pearson’s correlation coefficient (R = 0.503). Z-analysis showed that statistical significance (p = 0.04) was noted for the height data Z-scores of patients between ≤10 years and >10 years at the final follow-up. Systemic chemotherapy did not reduce skeletal growth in young osteosarcoma patients as a late adverse effect based on two different evaluation methods. However, patients aged ≤10 years at diagnosis may develop a short stature after systemic chemotherapy.

Can “domino” therapy effectively treat the infection around the prosthesis after the limb salvage surgery of bone tumor? - A study of sequential therapy

BackgroundTumor resection and prosthetic replacement have become the treatments of choice for malignant bone tumors. Infections are the leading cause of failure of limb salvage surgeries. Therefore, treating infections around prostheses after limb salvage is essential and challenging. Our research team designed a “domino” sequential treatment plan to treat postoperative infections around tumor prostheses and evaluated its efficacy. PurposeTo introduce the new domino sequential treatment plan for postoperative infections of tumor prostheses, and evaluate the technical points of the plan and prognosis in medium- and long-term follow-ups. MethodsBetween January 2015 and August 2021, 14 patients were treated with prosthesis-preserving domino sequential therapy for peripheral prosthesis infections after bone-tumor limb salvage. The sample included eight cases of distal femur tumor, two of proximal tibia tumor, three of pelvic tumor, and one of middle femur tumor. We evaluated routine blood test results, C-reactive protein level, the erythrocyte sedimentation rate, and other indicators. X-rays and CT scans of the surgical site were obtained and the Musculoskeletal Tumor Society (MSTS) score was calculated. Treatment involved debridement and lavage of the prosthesis, and systemic and local antibiotics. ResultsThe positivity rate of microbial culture was 78.6%. There were three cases of Staphylococcus aureus, one of Staphylococcus epidermidis, two of methicillin-resistant Staphylococcus epidermidis, one of methicillin-resistant Staphylococcus aureus, two of Acinetobacter baumannii, one of Streptococcus lactis (group C), one of Streptococcus mitis, and three with negative cultures. In three cases, sequential treatment failed to control the infection. The operation success rate was 78.6% (11/14). One case eventually required amputation, and another required long-term wound dressings. To control the infection, a third had to be treated using antibiotic bone cement combined with the “intramedullary nail reverse double insertion” technique. The MSTS scores of patients before infection debridement and at the last follow-up showed statistically significant differences (t = 5.312, p = 0.02). ConclusionsThe prosthesis-preserving domino sequential method has certain advantages for treating bone-tumor limb salvage infections around the prosthesis. Level of evidenceLevel IV, therapeutic.

Modern methods of treatment of malignant tumors

Attempts to avoid limb amputation upon detection of a malignant bone or soft tissue tumor were made by surgeons as early as the beginning of our century. One of them was related to plasty according to F. Sauerbruch: after resection of the femur, the tibia was moved upwards and placed in the musculocutaneous bed, resulting in a stump suitable for prosthetics. Tikhov and Linberg performed an extensive resection of the scapula and the proximal end of the humerus, preserving an "elongated" and unstable, but mobile upper extremity. Preservation of stability of the lower extremity by implanting tumor prostheses seemed to be the most reasonable. The first operation of this type was performed in the late 1930s by A. Moore for a gigantoclavicular tumor of the proximal femur. In the late 50s and early 60s, with the development of hip arthroplasty, the tendency to develop and implant special prostheses for patients with tumor diseases also intensified.