Reconstruction of the elbow with distal humerus endoprosthetic replacement after tumor resection: a systematic review of the literature and institutional case series

BACKGROUND

Distal humerus replacement (DHR) is a modular endoprosthesis mainly used for bone reconstruction after resection of primary or metastatic bone lesions. Studies on DHR failure rates and postoperative functional outcomes are scarce. We sought to assess implant survival, modes of failure, and functional outcomes in patients undergoing DHR for oncologic indications.

METHODS

A systematic review of the PubMed and Embase databases was performed. PRISMA guidelines were followed for this manuscript. Our study was registered on PROSPERO (457,260). Quality appraisal of included studies was conducted using the STROBE checklist. Prosthetic failure was assessed using the Henderson classification for megaprosthetic failures. We additionally performed a retrospective review of patients treated with a DHR for oncologic indications at a large tertiary care academic center. Weighted means were calculated to pool data.

RESULTS

Eleven studies with a total of 162 patients met the inclusion criteria. Mean follow-up was 3.7 years (range, 1.66-8 years). Henderson type 2 failures (aseptic loosening) were the most common mode of failure, occurring in 12% of cases (range, 0%-33%). Five-year implant survival was 72% (range, 49%-93.7%). Mean postoperative Musculoskeletal Tumor Society (MSTS) score was 81.1 (range, 74-84.3). In our institutional case series, 2 out of 5 patients had DHR revision for periprosthetic fracture and aseptic loosening at 16 and 27 months after surgery, respectively.

CONCLUSIONS

Distal humerus replacement is a successful reconstruction strategy for tumors of the distal humerus, with high implant survival and good to excellent functional outcomes.

Metal Ion Release in Cancer Patients Following Megaprosthesis Salvage Surgery

BACKGROUND

Megaprostheses contain many more modular components than conventional total hip and knee arthroplasty, which may lead to higher serum levels of metal ions. The aim of this study was to determine serum concentrations of titanium, chromium, and cobalt ions in cancer patients after limb salvage surgery with a megaprosthesis.

METHODS

A retrospective, descriptive cohort analysis consisting of patients who underwent cancer-related limb salvage surgery with a megaprosthesis at our hospital between 2010 and 2020 was conducted. Baseline and follow-up data were extracted from clinical and surgical records. Blood samples were prospectively obtained. Descriptive statistics were used for the analysis.

RESULTS

A total of 71 patients underwent limb salvage surgery during the study period. Of these, 22 (10 women, 12 men) were included in the study. The mean age was 52 years (range, 21 to 80). Most cases (n = 16; 72.7%) involved the femur. Most patients (n = 14, 63.6%) underwent total knee megaprosthesis surgery. Implant revision surgery was required in 45% of cases (n = 10), with a mean interval of 4.32 years between the initial and revision surgeries. The mean follow-up time after revision surgery was 4.05 years. High levels of chromium were observed in 22.7% of patients (n = 5). High cobalt levels were found in 68.2% (n = 15) of patients, with toxic levels in 9.1% (n = 2). Titanium levels were high in 77.3% (n = 17) of cases and toxic in 22.7% (n = 5). Postoperative chemotherapy was significantly associated with titanium levels (P = .017). No correlation was observed between metal ion levels and time from primary or revision surgery or time from the first to revision surgery.

CONCLUSIONS

This study shows that cancer-related limb salvage surgery with megaprosthesis is associated with metal ion levels that exceed established safe thresholds. Compared to conventional hip arthroplasty, a higher proportion of the patients in this cohort presented elevated levels of metal ions.

LEVEL OF EVIDENCE

III.

Surgical Management of Periprosthetic Joint Infections in Hip and Knee Megaprostheses

Periprosthetic joint infection is a feared complication after the megaprosthetic reconstruction of oncologic and non-oncologic bone defects of including the knee or hip joint. Due to the relative rarity of these procedures, however, optimal management is debatable. Considering the expanding use of megaprostheses in revision arthroplasty and the high revision burden in orthopedic oncology, the risk of PJI is likely to increase over the coming years. In this non-systematic review article, we present and discuss current management options and the associated results focusing on studies from the last 15 years and studies from dedicated centers or study groups. The indication, surgical details and results in controlling infection are presented for debridement, antibiotics, irrigation and retention (DAIR) procedure with an exchange of the modular components, single-stage implant exchange, two-stage exchanges and ablative procedures.

Elbow Reconstruction with Megaprosthesis: An Effective Strategy for Salvage Surgery in Trauma Patients

Delayed fracture healing can have devastating functional consequences, including pseudoarthrosis. Many factors can contribute to delayed healing, including decreased vascularity, micro-motion at the fracture site, large fracture gaps, multiple traumas at the same site, compromised metabolic status, surgical complications, and other conditions. A 61-year-old female patient was referred to our hospital with left distal humeral pseudarthrosis, accompanied by chronic pain and disability. Two years prior, the patient suffered a traumatic incident. At another medical facility, the patient underwent open reduction and internal fixation surgery with simultaneous ulnar nerve transposition. She showed favorable postoperative recovery. Unfortunately, approximately one year later, the patient sustained a second trauma to the same arm. This led to peri-implant fracture and post-traumatic aseptic degradation of the osteosynthesis system which was subsequently removed. Twelve months after the last surgery, the patient was referred to our hospital and, after thorough consideration of the therapeutic options, we decided to perform left elbow arthroplasty with left distal humeral reconstruction by using Zimmer's Comprehensive Segmental Revision System. This approach is generally reserved for tumors, and only a handful of cases of megaprostheses for non-tumoral indications have been previously reported. The surgery and perioperative care of our patient were optimal, there were no complications, and the patient recovered arm functionality following rehabilitation.

Topical Application of Vancomycin Powder to Prevent Infections after Massive Bone Resection and the implantation of Megaprostheses in Orthopaedic Oncology Surgery

Introduction

Periprosthetic joint infection (PJI) represents a serious burden in orthopaedic oncology. Through the years, several local expedients have been proposed to minimise the risk of periprosthetic infection. In this study, we report our outcomes using topical vancomycin powder (VP) with the aim to prevent PJIs.

Materials and methods

Fifty oncological cases treated with massive bone resection and the implant of a megaprosthesis were included in our study. Among them, 22 [(GGroup A) received one gram of vancomycin powder on the surface of the implant and another gram on the surface of the muscular fascia]. The remaining 28 did not receive such a treatment (Group B). The rest of surgical procedures and the follow-up were the same for the two groups. Patients underwent periodical outpatient visits, radiographs and blood exams' evaluations. Diagnosis of PJIs and adverse reactions to topical vancomycin were recorded.

Results

None of the cases treated with topical vancomycin developed infections, whereas 6 of the 28 cases (21.4%) who did not receive the powder suffered from PJIs. These outcomes suggest that cases treated with VP had a significantly lower risk of post-operative PJI (p=0.028). None of our cases developed acute kidney failures or any other complication directly or indirectly attributable to the local administration of VP.

Conclusions

The topical use of vancomycin powder on megaprosthetic surfaces and the overlying fascias, alongside with a correct endovenous antibiotic prophylaxis, can represent a promising approach in order to minimise the risk of periprosthetic infections in orthopaedic oncology surgery.

Can the Current Thresholds for Synovial Cell Count and Neutrophil Percentage to Diagnose Prosthetic Joint Infection be Applied to Metal-on-Metal Rotating Hinge Total Knee Arthroplasty?

BACKGROUND

Synovial leukocyte count analysis is an important tool in the diagnosis of PJI. However, results can be poor if metallosis is present. The issue of metallosis was established for some rotating hinge knee arthroplasty designs.

METHODS

This was a retrospective single-center analysis that included 108 patients who had a single-design metal-on-metal rotating hinge knee arthroplasty who underwent revision surgery and had prior synovial fluid analysis performed. The diagnostic accuracy of leukocyte count and the percentage of polymorphonuclear neutrophiles (% PMN) were investigated.

RESULTS

Patients who had a PJI had a higher median leukocyte count and % PMN compared to aseptic revisions (7,905/μL (interquartile range (IQR) 2,419 to 37,400) and 85% (IQR 70.3 to 93.8) versus 450 (IQR 167 to 1,215) and 46% (IQR 28.5 to 67.4%), P < .001). The respective areas under the curves were 0.916 (95% confidence interval 0.862 to 0.970) for leukocyte count and 0.821 (95% confidence interval 0.739 to 0.902) for % PMN. We calculated an optimal cut-off value of 1,200 leukocytes/μL (Sensitivity 94.5%/specificity 75.5%) and 63% PMN (Sensitivity 85.5%/specificity 73.6%) to define PJI. Established thresholds were less sensitive, but more specific. The "infection likely" scenario of the European Bone and Joint Infection Society (EBJIS) definition was closest to the calculated thresholds.

CONCLUSION

Currently used thresholds for leukocyte cell count and %PMN to define PJI were less sensitive and specific in the diagnosis of PJI in metal-on-metal RHK knees. Surgeons must consider lower cut-off values when evaluating such implants for PJI.

Debridement, Antibiotics, and Implant Retention (DAIR) Plus Offers Similar Periprosthetic Joint Infection Treatment Success Rates to Two-Stage Revision in Oncologic Megaprosthesis

BACKGROUND

Prosthetic joint infections (PJIs) after megaprosthesis implantation are associated with high rates of treatment failure and amputation. Our study analyzed PJI treatment success rates by surgical strategy and assessed risks of reinfection and amputation.

METHODS

We retrospectively analyzed the outcomes of patients diagnosed with PJI after undergoing megaprosthesis implantation for oncologic indications. The 2011 Musculoskeletal Infection Society criteria were used to define PJI. Reinfection, reoperation, and amputation for PJI recurrence were assessed. A total of 67 patients with megaprosthesis PJIs were included. There were fourteen patients who were treated with debridement, antibiotics, and implant retention (DAIR), 31 with DAIR plus (DAIR with modular component exchange and stem retention), and 21 with two-stage revisions. Kaplan-Meier estimates were used for survival analyses and Cox proportional hazards for risk factor analyses.

RESULTS

The two-year reinfection-free survival was 25% for DAIR and 60% for DAIR plus or two-stage revision (P = .049). The five-year amputation-free survival was 84% for DAIR plus or two-stage revision, and 48% for DAIR (P = .13). Reinfection-free, reoperation-free, and amputation-free survival were similar between DAIR plus and two-stage revision at the 2- and 5-year marks. Body mass index ≥30 (hazard ratio [HR] = 2.65) and chronic kidney disease (HR = 11.53) were risk factors for reinfection. Treatment with DAIR plus or two-stage revision (HR = 0.44) was a protective factor against reinfection.

CONCLUSIONS

A DAIR was associated with high rates of treatment failure and higher amputation rates than DAIR plus or 2-stage surgery. A DAIR plus was not inferior to 2-stage revision clearing a PJI and might be performed in patients who cannot withstand two-stage revision surgery.

Distal Femur Megaprostheses in Orthopedic Oncology: Evaluation of a Standardized Post-Operative Rehabilitation Protocol

BACKGROUND AND OBJECTIVES

Megaprostheses are the most used reconstructive approach for patients who have undergone massive resection of their distal femurs due to bone tumors. Although the literature about their outcomes has flourished in recent decades, to date, a consensus on rehabilitative treatment is yet to be established. In this study, we report on our experience with our latest standardized rehabilitation program, evaluating our results in a mid-to-long-term scenario.

MATERIALS AND METHODS

We evaluated the functional results of all our oncologic patients treated between 2016 and 2022 who could follow our standardized post-operative rehabilitative approach, consisting of progressive knee mobilization and early weight-bearing.

RESULTS

Sixteen cases were included in our study. The average duration of the patients' hospitalization was 12.2 days. A standing position was reached on average 4.1 days after surgery, while assisted walking was started 4.5 days after surgery. After a mean post-operative follow-up of 46.7 months, our patients' mean MSTS score was 23.2 (10-30). Our data suggest that the sooner patients could achieve a standing position (R = -0.609; p = 0.012) and start walking (R = -0.623; p = 0.010), the better their final functional outcomes regarding their MSTS scores.

CONCLUSIONS

Rehabilitation should be considered a pivotal factor in decreeing the success of distal femur megaprosthetic implants in long-surviving oncologic patients. Correct rehabilitation, focused on early mobilization and progressive weight-bearing, is crucial to maximizing the post-operative functional outcomes of these patients.

Silver-Coated Distal Femur Megaprosthesis in Chronic Infections with Severe Bone Loss: A Multicentre Case Series

Periprosthetic joint infections (PJI) and fracture-related infections (FRI) of the distal femur (DF) may result in massive bone defects. Treatment options include articulated silver-coated (SC) megaprosthesis (MP) in the context of a two-stage protocol. However, there is limited evidence in the literature on this topic. A retrospective review of the prospectively maintained databases of three Institutions was performed. Forty-five patients were included. The mean follow-up time was 43 ± 17.1 months. Eight (17.8%) patients had a recurrent infection. The estimated recurrence-free survival rate was 91.1% (93.5% PJI vs. 85.7% FRI) 2 years following MP implantation, and 75.7% (83.2% PJI vs. 64.3% FRI; p = 0.253) after 5 years. No statistically relevant difference was found according to the initial diagnosis (PJI vs. FRI). Among possible risk factors, only resection length was found to significantly worsen the outcomes in terms of infection control (p = 0.031). A total of eight complications not related to infection were found after reimplantation, but only five of them required further surgery. Above-the-knee amputation was performed in two cases (4.4%), both for reinfection. Articulated DF SC MP in a two-stage protocol is a safe and effective treatment for chronic knee infection with severe bone loss.

Two-Stage Exchange Using a Total Femur Spacer in the Management of Periprosthetic Joint Infection - Spacer Complications and Implant Survivorships

BACKGROUND

Chronic periprosthetic joint infection after revision hip and knee arthroplasties can lead to subsequent massive femoral bone loss. In these cases, resection of the residual femur and placement of an antibiotic total femoral spacer can be an option to salvage the limb.

METHODS

This is a single-center retrospective analysis of 32 patients (median age 67 years; range 15-93; 18 women) who underwent placement of a total femur spacer for chronic periprosthetic joint infection with massive femoral bone loss between 2010 and 2019 as part of a planned two-stage exchange. The median follow-up period amounted to 46 months (range, 1-149). Implant and limb survival were analyzed using Kaplan-Meier survival estimates. Potential risk factors for failure were analyzed.

RESULTS

There were 34% (11 of 32) of patients having a spacer-associated complication, and 25% underwent revision for this reason. After the first stage, 92% were considered infection-free. There were 84% of patients who underwent second-stage reimplantation of a total femoral arthroplasty using a modular megaprosthetic implant. Infection-free implant survival was 85% after 2 years and 53% after 5 years. There were 44% of patients who underwent amputation after a median time of 40 months (range, 2-110). Most commonly, coagulase-negative staphylococci were cultured at first-stage surgery, while polymicrobial growth was most common at reinfection.

CONCLUSION

Total femur spacers can lead to infection control in over 90% of cases with a reasonable complication rate for the spacer itself. However, the reinfection and subsequent amputation rate after second-stage megaprosthetic total femoral arthroplasty is around 50%.

Proximal Tibia Primary Leiomyosarcoma: A Case Report and Review of Literature

The paper at hand presents a unique case of leiomyosarcoma (LMS) involving the left leg in a 56-year-old patient. This individual experienced pain and the presence of a mass for approximately eight months before seeking medical attention. A diagnostic biopsy revealed the presence of multinucleated pleomorphic cells arranged in intersecting fascicles upon immunohistochemistry (IHC) staining for vimentin, caldesmon, and smooth muscle actin. The rarity of LMS in the extremities highlights the need for further understanding and research to determine the most suitable treatment approaches for such patients. In this specific case, the patient underwent tumor excision followed by reconstruction using a megaprosthesis. This report emphasizes the importance of considering unique treatment strategies when dealing with rare neoplasms like LMS in the extremities. As medical knowledge continues to evolve, gaining insights into the optimal management of such cases will be crucial for improving patient outcomes and overall prognosis.

Distal Humeral Replacement in Patients with Primary Bone Sarcoma: The Functional Outcome and Return to Sports

Distal humeral replacement (DHR) is a limb-salvage option for the endoprosthetic reconstruction of bone defects following the resection of a primary bone sarcoma. As primary bone sarcomas are only occasionally located around the distal humerus, there is a paucity of information regarding postoperative function, and patients' resumption of sporting activities. With advances in diagnostics and in surgical and oncological treatment leading to an increased patient life expectancy and higher quality of life, patients' functional outcome and return to sports activities are of increasing interest. Between 1997 and 2021, a total of 24 patients underwent DHR with a single-design modular implant at a tertiary sarcoma center. A total of 14 patients who died of their disease were excluded, leaving a study cohort of 10 patients, with a median age of 30 years on the day of surgery (IQR 20-37). At the last follow-up, after a median of 230 months (IQR 165-262), the median MSTS was 19 (IQR 13-24), the median TESS was 79 (IQR 66-87), the median SEV was 38% (IQR 24-53), the median TS was 6 (IQR 4-7), and the median WAS was 3 (IQR 1-8). Among the variables of gender, surgery on the dominant extremity, intraoperative nerve resection, extra-articular tumor resection, chemotherapy, radiotherapy, and revision surgeries, none were associated with a better/lower functional outcome score or return to sports activities. However, a higher level of sports performance prior to diagnosis (WAS > 10) was associated with a higher level of sports performance postoperatively (p = 0.044).

Limb Salvage Strategy Amendment for a Better Future in the Era of Bone Cancer Therapy: A Cross-Sectional Study in North India

BACKGROUND

 Bone tumors remain a formidable challenge for orthopedic surgeons. In developing countries, the challenge is exacerbated by limited diagnostic, therapeutic, and management facilities and ignorance. Patients with upper and lower-extremity muscle and skeletal tumors are candidates for amputation or surgical rescue of the limbs. Traditionally, limb rescue surgery by neo-adjuvant chemotherapy is the preferred surgery method for localized carcinoma. Amputations are usually reserved for patients with increased tumor size. The purpose of this study is to investigate health-related quality of life (HRQOL) and physical disability, focusing on surgical care, gender, and age, in adolescent and young adult survivors of malignant bone tumors treated surgically.

METHODS

 This cross-sectional study consists of 38 long-term survivors who underwent amputation or limb-salvage surgery at King George's Medical University, Lucknow, from 2019 to 2022. After obtaining ethical clearance and informed consent, 38 patients which included 26 patients treated with limb salvage in Group A and 12 patients treated with amputation in Group B were included in the study. The SF-36 and HUI3 scores were used to assess the functional outcome and health-related QoL of these patients.

RESULTS

 After minimal six months of interventions, we have found a significant improvement in all the following factors: physical functioning (P=0.000), role limitations due to physical health (P=0.000) and emotional problems (P=0.001), energy/fatigue (P=0.000), emotional well-being (P=0.000), social functioning (P=0.000), pain (P=0.000), and general health (P=0.000). Group A showed a higher degree of significance than Group B through SF-36 (Short Form-36, patient-reported outcome), whereas HUI-3 did not show any significant outcomes (P=0.347).

CONCLUSION

 The overall quality of life of patients with salvaged limbs appears to be higher than that of the quality of life of amputee patients in tumor survivor patients. Further analyses must be carried out to verify the results and focus on areas that have a major impact on the overall quality of life using other assessment tools. The impact of therapy on the quality of life depends on maintaining the necessary structures for functional functions, adjusting patient expectations to cancer treatments, and designing long-term rehabilitation programs to support functional functions.

Megaprosthesis in Non-Oncologic Settings-A Systematic Review of the Literature

Modular megaprostheses (MPs) are commonly used after bone-tumor resection, but they can offer a limb salvage solution in massive bone defects. The aim of this systematic review of the Literature is to provide a comprehensive data collection concerning the use of MPs in non-oncologic cases, and to provide an overview of this topic, especially from an epidemiologic point of view. Three different databases (PubMed, Scopus, and Web of Science) were searched for relevant articles, and further references were obtained by cross-referencing. Sixty-nine studies met the inclusion criteria, reporting on cases of MP in non-oncologic cases. A total of 2598 MPs were retrieved. Among these, 1353 (52.1%) were distal femur MPs, 941 (36.2%) were proximal femur MPs, 29 (1.4%) were proximal tibia MPs and 259 (10.0%) were total femur MPs. Megaprostheses were most commonly used to treat periprosthetic fractures (1158 cases, 44.6%), in particular in the distal femur (859, 74.2%). Overall, complications were observed in 513 cases (19.7%). Type I (soft tissue failures) and type IV (infection) according to the Henderson classification were the most frequent (158 and 213, respectively). In conclusion, patients with severe post-traumatic deformities and/or significant bone loss who have had previous septic complications should be considered as oncologic patients, not because of the disease, but because of the limited therapeutic options available. The benefits of this treatment include relatively short operative times and immediate weight-bearing, thus making MP particularly attractive in the lower limb.

Functional Outcomes and Shoulder Instability in Reconstruction of Proximal Humerus Metastases

(1) Background: Some of the goals of orthopedic surgical oncology are saving limbs and function. The humerus is the third most frequent site in primary tumors and one of the most involved sites for metastases. Prosthetic replacement with modular megaprosthesis is one of the treatment choices, but there are several types of complications, such as problems with function and pain. The aim of our study is to assess functional outcomes and shoulder instability in the reconstruction of proximal humerus metastases. (2) Methods: This is a retrospective observational study. Twenty-eight patients, with proximal humerus metastases, admitted to the department of Orthopaedics and Traumatology of our University Hospital between 2014 and 2022 were recruited. Each patient underwent resection and prosthetic replacement surgery with modular megaprosthesis. Clinical evaluation was assessed through MSTS score, WOSI index, and DASH score. (3) Results: Twenty patients were included in the study. Fairly good results, especially regarding pain, function, and emotional acceptance, were obtained in all three tests: DASH, MSTS, and WOSI. Patients who reported shoulder instability actually have worse outcomes than those who report having stable shoulders. In addition, patients with a resection >10 cm have worse outcomes than those who had a resection of 10 cm. No significant differences were found between the deltopectoral approach group and the lateral approach group. (4) Conclusions: Reconstructive surgery with megaprosthesis of the proximal humerus in patients with metastases can be considered a treatment option, especially in patients with pathological fractures or injuries with a high risk of fracture and good life expectancy. This study shows how this type of surgery affects instability, but in terms of functionality, pain, and patient satisfaction, it gives satisfactory results.

The major proximal femoral defects: megaprosthesis in non oncological patients - A case series

We identified 39 patients (23 female and 16 male) underwent hip revisions through mega-prosthesis. The most common causes were periprosthetic fractures, periprosthetic osteolysis and consequences of infected arthroplasty. The average follow-up was 5 years (2.1 to 6.5), and average age was 69 years (47 to 78). At the final follow-up all the implants resulted functional and osteointegrated. The Merle D'Aubignè and Postel hip rating scale was used for the evaluation, better results were observed in periprosthetic fractures. Postoperative complications occurred in eight patients. Thus, megaprosthesis were a reasonable surgical option in the management of major femoral defects.

Malignant Transformation in Ollier's Disease: A Novel Stem for a Tibial Megaprosthesis

Ollier's disease is a rare syndrome characterized by multiple enchondromas with the potential for malignant transformation. The treatment for secondary chondrosarcoma is surgical resection, which can be a morbid procedure depending on the location and size of the tumor. We present a successful limb salvage in which the majority of the tibia was removed and replaced with a megaprosthesis. The complex reconstruction in this case required the use of a novel uncemented stem.

En Bloc Resection With Reconstruction Using a Customized Megaprosthesis in a Case of Proximal Humerus Giant Cell Tumor: A Case Report

A giant cell tumor is a common, benign but locally aggressive bone tumor faced by orthopedic surgeons. The proximal humerus is a rare site of occurrence for this tumor, and the challenges posed while approaching such a case are discussed in this report of a 29-year-old male who presented with pain, swelling, and restricted motion at the left shoulder. Plain radiographs and MRI were suggestive of an aggressive giant cell tumor of the proximal humerus, which was confirmed on histopathological examination. Due to the lesion's extensive soft-tissue involvement, en-bloc resection with reconstruction was planned, but due to the COVID-19 pandemic, surgery was delayed. During the same period, the patient had trivial trauma to the same shoulder, following which the size of the lesion began increasing. The patient was operated on with en-bloc resection and reconstruction with a custom megaprosthesis; following the surgery, there was a complete resolution of pain and improvement in the range of motion. En bloc resection and replacement with a customized megaprosthesis, though technically demanding, offer a safe and cost-effective modality for limb salvage surgery for large giant cell tumors, with good functional outcomes and decreased chances of recurrence.

Reconstruction With a 3D-Printed Megaprosthesis With Ankle Arthrodesis After Distal Tibial Tumor Resection

BACKGROUND

Reconstruction after en bloc resection of the distal tibia has remained an unsettled issue despite many attempts with bone grafts or prostheses in the past. Failures of the previous methods have been attributed to inadequate mechanical strength, poor articular stability, failed osseointegration, and poor soft tissue coverage. To overcome these shortcomings, we designed and applied a 3D-printed megaprosthesis with ankle arthrodesis.

METHODS

A total of 13 patients underwent resection of a distal tibial tumor and reconstruction with a 3D-printed distal tibial megaprosthesis between January 2017 and November 2020. Mean age was 14.9±6.5 years. Diagnoses included 11 cases of osteosarcoma and 1 case each of low-grade phosphaturic mesenchymal tumor and rhabdomyosarcoma. Baseline characteristics, operative data, complication profiles, and oncologic, and functional outcomes were reviewed and analyzed.

RESULTS

All 13 cases attained a wide or marginal resection. During a mean follow-up of 26.8±10.6 months, 1 patient experienced local recurrence and distant metastasis, whereas 3 other patients only developed distant metastasis. Periprosthetic infection subsequent to paronychia occurred in 1 patient 24 months after the operation. No other complications were observed. By the last follow-up, the mean MSTS-93 score was 28.0±1.5.

CONCLUSION

In this relatively small cohort with short-term follow-up, reconstruction with the 3D-printed megaprosthesis with ankle arthrodesis was found to be a safe and efficacious method after resection of a distal tibial malignancy.

Effect of an Endoprosthetic Reconstruction Tube and Medial Gastrocnemius Flap on Extensor Mechanism Function After Oncologic Prosthesis Reconstruction of the Proximal Tibia

BACKGROUND

Extensor mechanism reconstruction after the proximal tibial resection and implantation of a megaprosthesis is challenging. In this study, we evaluated the effectiveness of the Trevira tube and medial gastrocnemius flap in restoring extensor mechanism following the resection of proximal tibial tumor and implantation of megaprosthesis.

METHODS

Forty patients who underwent endoprosthetic implantation following the resection of proximal tibial tumor and patellar tendon reconstruction with the Trevira tube and medial gastrocnemius flap were included. The outcome measures were knee range of motion, extensor mechanism function, patellar position, and limb function subjectively evaluated through Toronto Extremity Salvage Score and objectively through Musculoskeletal Tumor Society score. The mean follow-up of the patients was 6.1 years.

RESULTS

The patellar position was normal in 28 (70%) patients, patella baja in 3 (7.5%) patients, and patella alta in 9 (22.5%) patients. The mean active knee range of motion was 98.9 ± 17° (range: 85°-125°). Extension lag was present in 7 (17.5%) patients (range: 5°-20°). The mean Toronto Extremity Salvage Score of patients was 92.1 ± 6.9% (range: 85-100). The mean Musculoskeletal Tumor Society score of the patients was 87.7 ± 13 (range: 73.3-100). Postoperative complications included aseptic wound dehiscence (2 patients), aseptic loosening of the tibial component (1 patient), periprosthetic fracture in the femur (2 patients), and wound infection (1 patient).

CONCLUSION

Trevira tube combined with gastrocnemius flap augmentation is a suitable procedure for restoring extensor mechanism after proximal tibial resection and megaprosthesis implantation.

Distal Femoral Replacement for Periprosthetic Fractures After TKA: Australian Orthopaedic Association National Joint Replacement Registry Review

BACKGROUND

Distal femoral replacement (DFR) is a potential treatment option following periprosthetic fracture (PPF) of a total knee arthroplasty (TKA). However, there is limited literature regarding implant survivorship and complication rates. The aim of this study was to examine patient demographics and trends in usage, implant survivorship and modes of failure, and patient mortality following DFR for PPF captured by a national joint replacement registry.

METHODS

A retrospective registry review was performed using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). In total, 306 DFR were performed for PPF of a known primary TKA. Eighty-five percent of patients were female, and the mean age was 76.4 years. Kaplan-Meier estimates of implant and patient survivorship were performed.

RESULTS

The number of DFR performed for PPF has doubled over the past five years. The cumulative percent second revision rate at six years was 12%. The most common indications for revision were infection (37%) and aseptic loosening (33%). Patient survivorship after DFR was 97% and 83% at five and ten years, respectively.

CONCLUSION

A national registry review has identified the increasing prevalence of DFR for PPF after primary TKA and demonstrated implant survivorship of 88% at midterm follow-up. Surgeons may consider DFR as an acceptable and durable treatment option.

LEVEL OF EVIDENCE

Level III - Case Series.

Elbow hemiarthroplasty with a 3D-printed megaprosthesis for defects of the distal humerus or proximal ulna after tumour resection : a preliminary report

AIMS

The aim of this study was to investigate the feasibility of application of a 3D-printed megaprosthesis with hemiarthroplasty design for defects of the distal humerus or proximal ulna following tumour resection.

METHODS

From June 2018 to January 2020, 13 patients with aggressive or malignant tumours involving the distal humerus (n = 8) or proximal ulna (n = 5) were treated by en bloc resection and reconstruction with a 3D-printed megaprosthesis with hemiarthroplasty, designed in our centre. In this paper, we summarize the baseline and operative data, oncological outcome, complication profiles, and functional status of these patients.

RESULTS

Preparation of the prosthesis was a mean of 8.0 days (SD 1.5), during which time no patients experienced tumour progression. The mean operating time and intraoperative blood loss were 158.1 minutes (SD 67.6) and 176.9 ml (SD 187.8), respectively. All of the prostheses were implanted successfully. During a mean follow-up of 25.7 months (SD 7.8), no patients died, but four had complications (two superficial wound problems, one temporary palsy of radial nerve, and one dislocation). No aseptic loosening, structural failure, infection, heterotopic ossification, or degenerative arthritis was seen in this study. The mean flexion of the elbow was 119.6° (SD 15.9°) and the mean extension lag was 11.9° (SD 13.8°). The mean Musculoskeletal Tumor Society 93 score and Mayo Elbow Performance Score were 28.4 (SD 0.9) and 97.7 (SD 4.4), respectively.

CONCLUSION

The custom-made, 3D-printed megaprosthesis with hemiarthroplasty is a feasible option for functional reconstruction after resection of a tumour in the distal humerus or proximal ulna. Cite this article: Bone Joint J 2022;104-B(6):747-757.

Surgical Treatment of Bone Sarcoma

Bone sarcomas are rare primary malignant mesenchymal bone tumors. The three main entities are osteosarcoma, chondrosarcoma, and Ewing sarcoma. While prognosis has improved for affected patients over the past decades, bone sarcomas are still critical conditions that require an interdisciplinary diagnostic and therapeutic approach. While radiotherapy plays a role especially in Ewing sarcoma and chemotherapy in Ewing sarcoma and osteosarcoma, surgery remains the main pillar of treatment in all three entities. After complete tumor resection, the created bone defects need to be reconstructed. Possible strategies are implantation of allografts or autografts including vascularized bone grafts (e.g., of the fibula). Around the knee joint, rotationplasty can be performed or, as an alternative, the implantation of (expandable) megaprostheses can be performed. Challenges still associated with the implantation of foreign materials are aseptic loosening and infection. Future improvements may come with advances in 3D printing of individualized resection blades/implants, thus also securing safe tumor resection margins while at the same time shortening the required surgical time. Faster osseointegration and lower infection rates may possibly be achieved through more elaborate implant surface structures.

Worse Outcomes Are Associated With Proximal Femoral Replacement Following Periprosthetic Joint Infection

BACKGROUND

Proximal femoral replacements (PFRs) are often used in the setting of severe bone loss. As osteolysis has become less common, PFR may be used to address other causes of bone loss such as infection or periprosthetic fracture. The aim of this study is to investigate the clinical outcomes of PFR for non-neoplastic conditions.

METHODS

A retrospective review of 46 patients undergoing PFR at a single institution was performed. The electronic records were reviewed to extract relevant information including the reason for use of PFR, surgical variables, follow-up, and complications. Survivorship curves were generated and differences in survivorship were evaluated using the log-rank test. Radiographic evaluation was also performed.

RESULTS

Using revision as an endpoint, the Kaplan-Meier analysis of the entire cohort demonstrated a survival rate of 74% at 1 year and 67% at 5 years. Patients with a preoperative diagnosis of periprosthetic joint infection demonstrated the lowest survivorship with a failure rate of 47%. Furthermore, a high dislocation rate at 17.4% (n = 8) was observed. The use of dual-mobility articulation was effective in reducing dislocation.

CONCLUSION

PFR is a valuable reconstructive option for patients with massive proximal femoral bone loss. This study demonstrates that patients with periprosthetic joint infection who undergo PFR reconstruction are at very high risk of subsequent failure, most commonly from reinfection and instability. The use of a dual-mobility articulation in association with PFR appears to help mitigate risk of subsequent dislocation.

Implant Survival, Clinical Outcome and Complications of Megaprosthetic Reconstructions Following Sarcoma Resection

Simple Summary

Malignant bone and soft tissue tumors are usually surgically removed with an envelope of healthy tissue as a barrier. If located in the long bones of the upper and lower extremity, this approach leads to a large bone defect commonly affecting a joint. One way to rebuild the bone defect and the neighboring joint is the use of a megaprosthesis that is anchored in the remaining bone comparable to a conventional joint replacement. In general this approach is popular as it provides early stability and allows the affected patient to begin rehabilitation early on. However, complications leading to long-term unplanned reoperation are common. This article provides an overview of current implant survival, types of complication and long-term outcomes of megaprostheses used following tumor resection.

Abstract

Megaprosthetic reconstruction of segmental bone defects following sarcoma resection is a frequently chosen surgical approach in orthopedic oncology. While the use of megaprostheses has gained popularity over the last decades and such implants are increasingly used for metastatic reconstructions and in non-tumor cases, there still is a high risk of long-term complications leading to revision surgery. This article investigates current implant survivorship, frequency and types of complications as well as functional outcomes of upper and lower limb megaprosthetic reconstructions.

Application and Development of Megaprostheses in Limb Salvage for Bone Tumors Around the Knee Joint

In recent decades, limb-salvage surgery has replaced amputation as the first choice for the treatment of bone tumors around knee. After tumor resection, there are a variety of reconstruction methods for us to choose, including autograft or allograft, inactivation and reimplantation, artificial prosthesis replacement, and allograft-prosthesis compound reconstruction. Compared with other reconstruction methods, artificial prosthesis reconstruction has some advantages: relatively simple, early weight bearing, fewer early complications, and good function in the early and mid-term follow-up. After decades of continuous improvements, the design of tumor prosthesis has reached a relatively mature stage, and the failure rate of prosthesis has also been declining year by year. However, artificial prostheses also have multiple complications such as infection, aseptic loosening, prosthetic breakage, and patients sometimes face the risk of revision or amputation. Therefore, clinicians need to deeply understand the characteristics of related complications and the principles of treatment.

The Bateman-Type Soft Tissue Reconstruction around Proximal or Total Humeral Megaprostheses in Patients with Primary Malignant Bone Tumors-Functional Outcome and Endoprosthetic Complications

We aimed to evaluate the functional outcome and endoprosthetic complications following the Bateman-type soft tissue reconstruction around proximal or total humeral replacements in patients undergoing resection of a primary malignant bone tumor. Between September 2001 and December 2018, a total of 102 patients underwent resection of a primary malignant bone tumor and subsequent reconstruction with a modular humeral megaprosthesis in our department. Fifteen (15%) of these patients underwent a Bateman-type soft tissue reconstruction and were included in this retrospective study. The median Musculoskeletal Tumor Society (MSTS) score was 21, the median Toronto Extremity Salvage Score (TESS) was 70, and the median American Shoulder and Elbow Surgeons (ASES) score was 72. Fifty-three percent (8/15) of all patients required a revision surgery after a median time of 6 months. There were 2 soft tissue failures, 3 infections and 3 tumor recurrences. The revision-free implant survivorship amounted to 53% (95% confidence interval (CI) 28-81) after 1 year and 47% (95% CI 22-73) at last follow-up. The Bateman-type reconstruction is a feasible option for soft tissue reconstruction but functional outcome is overall limited and the risk for revision surgery within the first postoperative year is high.

Periprosthetic Stress Shielding of the Humerus after Reconstruction with Modular Shoulder Megaprostheses in Patients with Sarcoma

(1) Background: Modular megaprosthetic reconstruction using a proximal humerus replacement has emerged as a commonly chosen approach after bone tumor resection. However, the long-term risk for revision surgery is relatively high. One factor that might be associated with mechanical failures is periprosthetic osteolysis around the stem, also known as stress shielding. The frequency, potential risk factors, and the effect on implant survival are unknown. (2) Methods: A retrospective single-center study of 65 patients with sarcoma who underwent resection of the proximal humerus and subsequent reconstruction with a modular endoprosthesis. Stress shielding was defined as the development of bone resorption around the prosthesis stem beginning at the bone/prosthesis interface. The extent of stress shielding was measured with a new method quantifying bone resorption in relation to the intramedullary stem length. All patients had a minimum follow-up of 12 months with conventional radiographs available and the median follow-up amounted to 36 months. (3) Results: Stress shielding was observed in 92% of patients (60/65). The median longitudinal extent of stress shielding amounted to 14% at last follow-up. Fifteen percent (10/65) showed bone resorption of greater than 50%. The median time to the first radiographic signs of stress shielding was 6 months (IQR 3–9). Patients who underwent chemotherapy (43/65) showed a greater extent of stress shielding compared to those without chemotherapy. Three percent (2/65) of patients were revised for aseptic loosening, and one patient had a periprosthetic fracture (1/65, 1.5%). All these cases had >20% extent of stress shielding (23–57%). (4) Conclusions: Stress shielding of the proximal humerus after shoulder reconstruction with modular megaprosthesis is common. It occurs within the first year of follow-up and might be self-limiting in many patients; however, about one third of patients shows progression beyond the first year. Still, mechanical complications were rare, but stress shielding might be clinically relevant in individual cases. The extent of stress shielding was increased in patients who underwent perioperative chemotherapy. Stress shielding can be quantified with an easy method using the stem length as a reference.

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.

Does the Duration of Primary and First Revision Surgery Influence the Probability of First and Subsequent Implant Failures after Extremity Sarcoma Resection and Megaprosthetic Reconstruction?

Simple Summary

Tumor endoprostheses are a common type of reconstruction after the resection of an extremity bone sarcoma. However, in the long-term, first and subsequent implant failures leading to revision surgery are common. One potential risk factor for implant failure is the length of surgery. This study investigates the impact of the length of surgery on prosthetic survival in 568 patients with sarcoma. Patients who had a first implant failure had a longer surgery; however, there were no differences in the infection-free survival, but only in the probability of mechanical failure. Patients with a subsequent revision surgery for infection had a shorter duration of surgery during the first revision. In conclusion, a shorter surgery appears beneficial; however, longer surgeries are not clearly associated with infection. In revision surgery, a longer operating time, indicating a more thorough debridement, may be desirable.

Abstract

Complications in megaprosthetic reconstruction following sarcoma resection are quite common. While several risk factors for failure have been explored, there is a scarcity of studies investigating the effect of the duration of surgery. We performed a retrospective study of 568 sarcoma patients that underwent megaprosthetic reconstruction between 1993 and 2015. Differences in the length of surgery and implant survival were assessed with the Kaplan–Meier method, the log-rank test and multivariate Cox regressions using an optimal cut-off value determined by receiver operating curves analysis using Youden’s index. 230 patients developed a first and 112 patients a subsequent prosthetic failure. The median duration of initial surgery was 210 min. Patients who developed a first failure had a longer duration of the initial surgery (225 vs. 205 min, p = 0.0001). There were no differences in the probability of infection between patients with longer and shorter duration of initial surgery (12% vs. 13% at 5 years, p = 0.492); however, the probability of mechanical failure was higher in patients with longer initial surgery (38% vs. 23% at 5 years, p = 0.006). The median length of revision surgery for the first megaprosthetic failure was 101 min. Patients who underwent first revision for infection and did not develop a second failure had a longer median duration of the first revision surgery (150 min vs. 120 min, p = 0.016). A shorter length of the initial surgery appears beneficial, however, the notion that longer operating time increases the risk of deep infection could not be reproduced in our study. In revision surgery for infection, a longer operating time, possibly indicating a more thorough debridement, appears to be associated with a lower risk for subsequent revision.

A Giant Cell Tumor of the Distal Femur Managed by Excision and Knee Arthrodesis Using a Custom Made Long Intramedullary Interlocking Nail: A Case Report and Review of the Literature

Giant cell tumors (GCTs) are primary bone tumors that occur most commonly in long bones, with half such tumors occurring in the distal femur, proximal tibia, and fibula. Around 12% of patients present with a pathological fracture indicating more aggressive disease. Arthrodesis after tumor resection is a popular choice due to its affordability and early postoperative mobilization, as well as low risks of implant loosening, infections, malignant lesions, or mortality. A free fibular graft is a popular option in limb-sparing surgery for long bone tumors. A bone graft and nail can be used to reconstruct long bones and bridge defects up to 25 cm. In developing countries, the cost of the imported mega prosthesis, around 8,500 US$, means many patients cannot afford the treatment. We describe a case of a GCT of the distal femur treated by excision of the tumor and reconstruction using a fibular bone graft, with knee arthrodesis using a custom-made long intramedullary interlocking nail fixation across the femur to the knee and the tibia. The length was achieved with 1 cm shortening post-surgery. The result was satisfactory, and partial weight-bearing was allowed three months after the surgery. At the one-year follow-up, there was no recurrence, and the patient had the full weight-bearing ability.

Vascularised bone graft is an effective technique for extracortical bone bridging to combat cemented megaprosthesis loosening at the bone-implant junction

INTRODUCTION

The bone-implant junction is a potential site for aseptic loosening. Extracortical bone bridging at the bone-implant junction is advocated to improve implant fixation by forming a biological seal. We propose a novel technique with vascularised bone graft (VBG) to form an extracortical bone bridge at the bone-implant junction to enhance implant stability. We compared the clinical and radiological outcomes for tumour megaprostheses performed (1) with and without bone graft and (2) with non-vascularised versus VBG technique.

METHODS

Forty-six tumour megaprosthesis procedures from 1 June 2007 to 31 October 2017 were identified from hospital records. Twenty-eight operations incorporated bone graft at the bone-implant junction, and 18 did not. Of these 28 bone graft procedures, 13 involved VBG, and 15 did not (non-VBG). The VBG technique involves resecting a short segment of healthy bone beyond the oncological margin with its preserved blood supply, splitting it, then securing it over the junction. Clinical outcomes assessed included loosening, fracture and recurrence. Extracortical bone growth at the bone-implant junction was quantified radiologically at intervals 0-24 months post-operatively. The mean follow-up was 4.27 years.

RESULTS

There were five incidences (27.8%) of loosening in the non-bone graft group compared to zero in the bone graft group (p = 0.03). There was a higher radiological score of extracortical bone growth in the bone graft group compared to no bone graft at 3-24 months post-operatively (p < 0.05). Within the bone graft group, the VBG group fared superior at 6 and 12 months post-operatively compared to non-VBG (p < 0.05), as well as a lower rate of radiological junctional resorption (p = 0.04).

CONCLUSIONS

We recommend bone grafting for its merits of less implant loosening. We propose the VBG technique to combat early aseptic loosening in megaprosthesis replacement as there was a higher radiological score compared to non-VBG.

Reconstruction of infected post-traumatic bone defects of the distal femur with the CompressⓇ implant. Preliminary results of a staged non-biological strategy

INTRODUCTION

Infected post-traumatic distal femur defects remain a therapeutic challenge. Non-biological reconstruction offers an option for avoiding complex biological knee arthrodesis procedures. The Compress^Ⓡ implant is an alternative to the traditional distal femur stemmed megaprosthesis. The aim of this study is to analyse the first patients treated with a distal femur Compress^Ⓡ prosthesis to manage massive infected post-traumatic defects of the distal femur with joint involvement.

METHODS

We retrospectively reviewed all patients with massive infected defects of the distal femur where this implant was used in a two-stage strategy, together with an antibacterial coating hydrogel (DAC^Ⓡ). The specific protocol, microbiological data, clinical and radiological results, complications, functional results and prosthesis survivorship were determined. Follow-up was for a minimum of 12 months, or until implant removal.

RESULTS

Ten patients (11 Compress^Ⓡ implants) with a mean age of 52 years (range 35-73) were included. On average, patients had undergone 4.4 previous surgical procedures before index surgery. The mean bone defect was 14 cm (range 8-21). After a median follow-up of 27 months (range 12-50 months) no patient had presented with recurrence of the infection, and limb salvage was achieved in all cases. Two patients suffered aseptic loosening which required revision of the femoral component. The short-term survivorship of the implant in our series was 81.8% at 4 years, with all failures occurring in the first 7 months. After this 7-month time threshold, we encountered no further loosening. Regarding functional outcomes, patients had a mean knee ROM of -4/86, expressed high overall satisfaction with the procedure according to the SAPS scale, and had an average LEFS of 52.5% (40-72.5%).

CONCLUSION

Non-biological reconstruction of the distal femur with the Compress^Ⓡ implant is a valid option in selected patients with massive infected defects with joint involvement. Survivorship was high, with all loosening occurring in the first months after surgery-representing a failure in the osseointegration of the implant.

Combined Techniques of Non-invasive 99mTc-Besilesomab/99mTc-Sulfur Colloid with Hybrid SPECT/CT Imaging in Characterising Cellulitis from Symptomatic Perimegaprosthetic Infection: A Case Report

Megaprosthesis is used to restore the form and function of massive skeletal defects, but it is accompanied by risks of failure, mainly due to perimegaprosthetic infection (PMI). In practice, the diagnosis of infected megaprosthesis among patients with a high index of clinical suspicion, elevated serological markers, and multiple negative or inconclusive imaging can be very challenging and poses a diagnostic conundrum to many orthopaedic surgeons. We present the case of a symptomatic 26-year-old female with large B-cell lymphoma who developed cellulitis with suspected complication of PMI 15 months post-implantation. The combination of advanced nuclear medicine imaging strategies, i.e., ^99mTc-besilesomab/^99mTc-sulfur colloid scintigraphy with hybrid single-photon emission computed tomography/computed tomography (SPECT/CT) scanning helps to characterise and delineate both infections. Invasive procedures such as joint aspiration and biopsy were avoided, and the patient was successfully treated with antibiotics. Hence, we report a case where advanced imaging modalities were decisive in the investigation of PMI.

Outcome satisfaction in long-term survivors of oncologic limb salvage procedures

OBJECTIVE

We present data from our recently completed study that suggests that joint salvage is the key parameter in keeping the limb salvage ethos relevant.

METHODS

We reviewed all patients operated on nationally over 30 years (1978 to 2008). We identified 265 survivors of which 162 were available for evaluation at the time of survey.

RESULTS

There were 92 males and 70 females followed an average 9.1±SD3.1 years. Average age at survey was 38±SD17 years. ANOVA for mental health and TESS degree of importance for ADL identified that all categories of joint preservation were similar to an average group of people from the population. Physical health scores were significantly better amongst joint-preserved versus joint replacement patients (p = 0.003). Nevertheless, there was no significant difference between amputees with respect to physical health scores compared to arthrodesed and joint-replaced individuals. Biological reconstructions scored significantly better than metallic segmentary reconstructions (p < 0.001). Dissatisfaction appeared to correlate best with the presence of pain following reconstruction (p < 0.001).

CONCLUSIONS

While our study supports the finding of amputations being as satisfactory as arthrodeses and joint replacement salvage surgery, joint salvage was superior to all other categories. Assessments of equivalence should incorporate joint salvage and materials used as evaluable parameters.

Humeral head necrosis associated to shaft non-union with massive bone loss: a case report

Humeral non-union is a rare complication in shaft fractures, as well as humeral head necrosis is a possible complication in fracture involving the proximal third especially in four-part fractures. The presence of head osteonecrosis and diaphyseal non-union in the same arm represents a formidable challenge for an orthopaedic surgeon. We could not find any similar report in the literature dealing with this issue thus far. We present a case of a 65 years old woman referred to our hospital being affected by an atrophic humeral diaphyseal non-union with a massive bone loss (>10cm) associated to a humeral head osteonecrosis following a previous surgical procedures with a clear loosening of the hardware. At our institution,she was treated with hardware removal and insertion of a diaphyseal antibiotic spacer with Gentamycin for 2 months suspecting an active septic process at the union site despite negative cultural exams. Finally, she was treated with a cemented modular humeral megaprosthesis. At 20 months follow up, the patient, despite a reduced shoulder range of motion, referred to a pain-free recovery to an almost normal lifestyle, including car driving with no major disturbances. This case suggests that, in extreme selected cases following several failed treatments, megaprosthesis can represent a viable solution, especially in huge bone loss associated to joint degeneration, to ensure an acceptable return to a normal lifestyle.

The Potential Innovative Use of Bacteriophages Within the DAC® Hydrogel to Treat Patients With Knee Megaprosthesis Infection Requiring "Debridement Antibiotics and Implant Retention" and Soft Tissue Coverage as Salvage Therapy

Infection is the most dramatic complication in patients with knee megaprosthesis. Its management is more complex in comparison with patients with primary arthroplasty, with a high risk of relapse. Lytic bacteriophages are considered to have a high potential in patients with prosthetic joint infection as it has been demonstrated that they have a synergistic anti-biofilm activity with antibiotics. The Defensive Antibacterial Coating (DAC®) hydrogel is a hydrogel available in the market that has been designed to prevent the adherence of bacteria on a prosthetic joint and to have the ability to transport and release anti-bacterial substances such as antibiotics. We report here the case of a patient with a catastrophic relapsing Staphylococcus aureus knee megaprosthesis infection without prosthesis loosening. We firstly perform phage susceptibility testing of the patient's strain to select an active cocktail, under the supervision of the French health authority. Then, we performed, as salvage therapy, a debridement and implant retention procedure with application of a selected cocktail of bacteriophages that was prepared extemporaneously within the DAC® hydrogel. A free flap for soft tissue coverage was required and empirical antibiotic treatment was started immediately after the surgery. Unfortunately, at 5 days after the surgery, while the local aspect of the surgical site was favorable, the patient developed myocardial infarction which required emergency stenting and dual antiplatelet therapy that were rapidly associated with bleeding at the surgical site, leading to a new prosthesis exposition. As a consequence, a transfemoral amputation was finally performed several months later. We also evaluated in vitro the impact of DAC® hydrogel on bacteriophage activity and showed that the selected phages were released very rapidly from the DAC® hydrogel, and then their titers were stable for at least 6 h. This case demonstrated the feasibility of the use of bacteriophages within a hydrogel to treat patients for knee megaprosthesis infection during a debridement procedure. The implementation requires identification of the pathogen before the debridement in order to perform phage susceptibility testing of the patient's strain and to identify a hospital pharmacist who will accept to do the preparation and to take the responsibility of the magistral preparation.

Innovations in prevention of infections in oncological megaprostheses: a narrative review

Infection is a significant complication in oncological megaprostheses. The purpose of our study is to indagate the innovations and new trend about the prevention of infection in this kind of surgery. The research focused on the use of antimicrobic prophylaxis, the defensive antibacterial coating and the use of silver coated.

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.

Periprosthetic Fractures of the Distal Femur: Is Open Reduction and Internal Fixation or Distal Femoral Replacement Superior?

BACKGROUND

The purpose of this study is to compare open reduction and internal fixation (ORIF) to distal femoral replacement (DFR) for treatment of displaced periprosthetic distal femur fractures.

METHODS

We identified 72 patients with minimum 2-year follow-up following a displaced periprosthetic distal femur fracture: 50 were treated with ORIF and 22 with DFR. Outcomes were assessed with multivariate regression analysis and include Knee Society Scores (KSS), infection rates, revision incidence, and mortality.

RESULTS

Patients treated with DFR had a higher Charlson comorbidity index (5.2 vs 3.8; P = .006). The mean postoperative KSS were similar between groups, but the Knee Society Functional Scores were higher in the ORIF group (P = .01). Six ORIF patients (12%) and 3 DFR patients (14%) underwent a revision surgery (P = .1). In the ORIF group, 3 revisions were associated with periprosthetic infection, and 3 revisions occurred for aseptic nonunion. In the DFR group, 1 infection was treated with irrigation and debridement, and 2 cases of patellar maltracking resulted in 1 liner exchange with soft tissue release and 1 femoral revision for malrotation. More patients in the ORIF group required repeat revisions, with twice as many total revisions (P < .001). Six ORIF patients and 7 DFR patients died within 2 years (P = .26).

CONCLUSION

The Knee Society Functional Score favored ORIF, but the total incidence of revision was higher in the ORIF cohort. Given the high mortality and the substantial risk of reoperation in both groups, additional studies are needed regarding the prevention of and optimal treatment for patients with periprosthetic distal femur fractures.

En-Bloc Resection of Metastases of the Proximal Femur and Reconstruction by Modular Arthroplasty is Not Only Justified in Patients with a Curative Treatment Option-An Observational Study of a Consecutive Series of 45 Patients

Background: There is little conformity regarding the surgical treatment of metastasis of the proximal femur, especially in palliative patients with limited life expectancy. Patients and Methods: En-bloc resection of secondary bone malignancies of the proximal femur and reconstruction by modular arthroplasty was performed in a consecutive series of 45 patients. The mean follow-up period was 16.4 months (0.6–74.7). Results: The survival rate of all patients was 6.6% (95% CI: 0–14.9) at 74.7 months. There was no significant difference in patients with a solitary or disseminated disease at index operation (log-rank p = 0.1214). Recurrent dislocation was the most frequent local complication (n = 6) necessitating an open reduction in four cases. The use of a Trevira tube showed a higher risk of dislocation compared to the simple bonding of remaining soft tissue (6 out of 28 vs. 0 out of 17; Fisher test: p = 0.0463). The worst-case survival rate with the removal of the arthroplasty for any cause and/or loss to follow-up was 80.0% (95% CI: 44.9–100) at 74.7 months (n = 1 due to low-grade infection). Conclusions: En-bloc resection of metastases and reconstruction by modular arthroplasty is reliable even in patients with very limited life expectancy. Local complications due to tumor growth or instability after intralesional surgery could be managed successfully but recurrent dislocation as the most frequent complication has to be taken into account. The simple bonding of remaining soft tissue around the prosthesis without the use of an attachment tube may reduce the dislocation rate and reoperation risk.

Osteointegration in Compliant Self-Adjusting Compression Fixation Shown by Backscatter Electron Microscopy: A Case Report

Compliant self-adjusting compression implants are a novel approach to increase the durability of megaprosthesis fixation. However, there is no report of current implant designs that documents the bone-prosthetic interface of this implant. A well-fixed compliant, self-adjusting distal femoral replacement was retrieved from a patient undergoing revision unrelated to fixation. The prosthesis-bone interface was preserved, embedded in poly(methyl methacrylate), and sectioned into 2-4-mm slices. Slices were then imaged using backscatter electron microscopy, and ongrowth and ingrowth were quantified using imaging software. The average percentage of bony ongrowth from five successive sections was 52.5%, and the average percentage of ingrowth into the porous titanium surface was 13.5%. We found that bone ongrowth on the cortex between anchor plug and spindle averages more than 50% and up to 70% depending upon the slice examined with backscatter electron microscopy. Bone ingrowth was consistently around 13% on every slice examined. This is a new finding compared with prior spindle designs, likely due to the addition of hydroxyapatite-coated porous metal titanium surface on the spindle. This report is an important step in understanding the mechanism of bony fixation generated by this implant and supports its increased use in oncological and complex reconstructive situations.

Megaprosthetic replacement of the distal humerus: still a challenge in limb salvage

BACKGROUND

The distal humerus is a rare location of bone tumors. Because of the complexity of the elbow joint, poor soft-tissue coverage, and proximity of nerves and vessels, resection and endoprosthetic reconstruction are demanding.

METHODS

This retrospective study evaluated the clinical results after distal humeral resection and megaprosthetic reconstruction in 12 patients with an average age of 46 years. All patient files were reviewed for clinical information, and postoperative function and patients' contentment were assessed using the Musculoskeletal Tumor Society score.

RESULTS

The predominant diagnoses were bone and soft-tissue sarcoma (n = 6), giant cell tumor (n = 2), and renal cell carcinoma metastasis (n = 2). Local recurrence was the reason for secondary amputation in all cases (n = 3). The prosthetic survival rate after surgery was 82% at 2 years and 64% at 5 years. Reconstruction failure was mainly caused by aseptic loosening of the humeral stem, occurring in 27% (n = 3), followed by aseptic loosening of the ulnar stem in 9% (n = 1) and periprosthetic infection in 9% (n = 1). The mean Musculoskeletal Tumor Society score was 24 points (range, 20-30 points). An extension lag of more than 10° was noted in 6 patients (55%).

CONCLUSION

Our results suggest that limb salvage with a distal humeral replacement can achieve good functional results in most patients, although the complication rate with special emphasis on the loosening rate of the humeral stem is high. However, limb salvage was not achieved in 27% of patients because of local recurrence.

Hip megaprosthesis in oncological surgery: open questions

Prosthetic replacement with modular implants has become the most common reconstructive tech¬nique of bone loss of the lower limb after tumour resection. The use of the megaprosthesis in bone metastasis, silver-coated megaprosthesis and the use of Trevira tube are not uniform and represent an "open question" about the use of megaprosthesis. The following paper aims to review the current literature in this topic.

Principles of Management of Extremity Skeletal Metastasis

Understanding the epidemiology of extremity skeletal metastasis and the factors deciding the treatment decision-making are essential in developing a diagnostic and treatment strategy. This leads to optimum care and reduces disease-related burden. With the evolution of medical, radiation therapy, and surgical methods, cancer care has improved the quality of life for patients with improved survival and functional status in patients with skeletal metastasis. Based on the currently available literature, we have described a step-wise evaluation and management strategy of metastatic extremity bone disease. The present review article addresses various aspects and related controversies related to evaluation, staging, and treatment options in the management of extremity bone metastasis. This article also highlights the role of multidisciplinary involvement in management of extremity skeletal metastasis.

Intriguing Periprosthetic Fracture of Hip Stem and Proximal Femoral Replacement

Lateral femoral prosthesis perforation is an uncommon periprosthetic fracture. Periprosthetic fractures may be fixed with open reduction and internal fixation, or with revision arthroplasty, depending on the type of fracture, the condition of the host bone in the proximal femur, the stability of the implant, and occasionally the medical co-morbidities of the patient. Proximal femoral replacement is a complex and challenging procedure but provides a better chance of early mobilisation. We describe a case of treating a 71-year-old woman who presented with an unusual type of periprosthetic fracture, treated with a revision arthroplasty procedure using a proximal femur replacement.

Clinical Outcome of Massive Endoprostheses Used for Managing Periprosthetic Joint Infections of the Hip and Knee

BACKGROUND

Endoprosthetic replacement (EPR) is an option for management of massive bone loss resulting from infection around failed lower limb implants. The aim of this study is to determine the mid-term outcome of EPRs performed in the treatment of periprosthetic joint infection (PJI) and infected failed osteosyntheses around the hip and knee joint and identify factors that influence it.

METHODS

We retrospectively reviewed all hip and knee EPRs performed between 2007 and 2014 for the management of chronic infection following complex arthroplasty or fracture fixation. Data recorded included indication for EPR, number of previous surgeries, comorbidities, and organism identified. Outcome measures included PJI eradication rate, complications, implant survival, mortality, and functional outcome (Oxford Hip or Knee Score).

RESULTS

Sixty-nine EPRs (29 knees and 40 hips) were performed with a mean age of 68 years (43-92). Polymicrobial growth was detected in 36% of cases, followed by coagulase-negative staphylococci (28%) and Staphylococcus aureus (10%). Recurrence of infection occurred in 19 patients (28%): 5 were treated with irrigation and debridement, 5 with revision, 1 with above-knee amputation, and 8 remain on long-term antibiotics. PJI eradication was achieved in 50 patients (72%); the chance of PJI eradication was greater in hips (83%) than in knees (59%) (P = .038). The 5-year implant survivorship was 81% (95% confidence interval 74-88). The mean Oxford Hip Score and Oxford Knee Score were 22 (4-39) and 21 (6-43), respectively.

CONCLUSION

This study supports the use of EPRs for eradication of PJI in complex, multiply revised cases. We describe PJI eradication rate of 72% with acceptable functional outcome.

Non-unions

Non-union of long bones is a significant consequence of fracture treatment. Bone regeneration is a complex physiological process of bone formation which can be seen during normal fracture healing. An improved understanding of the molecular and cellular events that occur during bone repair and remodelling has led to the development of biologic agents that can augment the biological microenvironment and enhance bone repair. Currently, there are different strategies to augment the impaired or "insufficient" bone-regeneration process, including the "gold standard" autologous bone graft, free fibula vascularised graft, allograft implantation, and use of growth factors, osteoconductive scaffolds, osteoprogenitor cells and distraction osteogenesis. A lack of standardized outcome measures for comparison of biologic agents in clinical fracture repair trials, frequent off-label use and a limited understanding of the biological activity of these agents at the bone repair site have limited their efficacy in clinical applications.