Characteristics and outcome of infections associated with tumor endoprostheses

Coverage of lateral soft tissue defects with sartorius muscle flap after distal femoral replacement for malignant bone tumors

INTRODUCTION

To prevent infection after limb-sparing surgery for primary malignant bone tumors, it is important to cover the megaprosthesis with muscle tissue that has sufficient blood flow. Coverage with a lateral gastrocnemius flap has been reported in cases of distal femoral replacement in which the vastus lateralis and vastus intermedius muscles have been resected; however, the risk of peroneal nerve palsy is reportedly high because the muscle flap passes near the peroneal head. This study was performed to examine the postoperative outcomes of patients with primary malignant bone tumors of the distal femur who underwent wide resection (including the vastus lateralis and vastus intermedius muscles) followed by reconstruction with a megaprosthesis and coverage of the lateral side of the prosthesis with a sartorius muscle flap.

METHODS

We retrospectively analyzed three patients who underwent reconstruction with a megaprosthesis after wide resection of a primary malignant bone tumor of the distal femur involving the vastus lateralis and vastus intermedius muscles and reconstruction of the soft tissue defect on the lateral side of the prosthesis with a sartorius muscle flap.

RESULTS

The average defect size was 6 × 13 cm, the average time required for a sartorius muscle flap was 100 min, and the average implant coverage was 93%. The average postoperative follow-up period was 35 months, during which no postoperative complications such as infection, skin necrosis, or nerve palsy occurred.

DISCUSSION

The distally based sartorius muscle flap is easy to elevate in the supine position, has minimal functional loss after harvesting, and has minimal risk of nerve palsy. It can be advocated as the first option for coverage of soft tissue defects lateral to distal femoral replacement.

High Rates of Treatment Failure and Amputation in Modular Endoprosthesis Prosthetic Joint Infections Caused by Fungal Infections With Candida

BACKGROUND

Fungal prosthetic joint infections (PJIs) are rare yet severe events associated with high rates of recurrent infection. Although bacterial PJIs associated with megaprostheses are known to be associated with higher rates of recurrence and amputation, little is known about fungal PJIs near megaprostheses.

QUESTIONS/PURPOSES

In patients with fungal megaprosthesis PJIs from one institutional registry, we asked: (1) What were the most common microorganisms isolated? (2) What were the reoperation-, revision-, and amputation-free survival rates 1 and 2 years after surgery?

METHODS

We conducted a retrospective analysis of megaprostheses in our institutional database. Between 2000 and 2022, 86 patients with a diagnosis of PJI after megaprosthesis implantation were surgically treated at our institution. We considered patients with microbiological cultures that were positive for fungal organisms and who had a minimum follow-up of 2 years from the initial treatment for PJI. Ten patients with fungal megaprosthesis PJIs were included. Although four patients had a follow-up shorter than 2 years, all reached one of the study endpoints at that earlier interval, and therefore were included. All included patients were treated between 2016 and 2022, and the diagnosis of PJI was made in accordance with the 2011 Musculoskeletal Infection Society criteria. Patients were treated with either debridement, antibiotics, and implant retention (DAIR), DAIR-plus (debridement, antibiotics, modular implant component exchange, and stem retention), or one-stage or two-stage revision. In general, DAIR was used for acute PJIs, while DAIR-plus was performed in patients with chronic PJIs who were deemed medically unfit to endure the high morbidity associated with removal of the stems. In cases of prior unsuccessful DAIR-plus or patients with fewer comorbidities, one-stage or two-stage revision was the main treatment approach. The median age at diagnosis was 67 years (range 32 to 84 years), 5 of 10 patients were female, and the median BMI was 31 kg/m 2 (range 20 to 43 kg/m 2 ). The median follow-up was 26 months (range 1 to 54 months). A Kaplan-Meier survival analysis was performed to calculate reoperation-, revision-, and amputation-free survival at 1 and 2 years from the index surgery for PJI.

RESULTS

The two most common organisms were Candida albicans (5 of 10 patients) and C.parapsilosis (3 of 10). Six of 10 patients had coinfection with a bacterial organism. One-year reoperation-free and revision-free survival were 35% (95% CI 9% to 64%) and 42% (95% CI 11% to 71%), respectively. Two-year reoperation-free and revision-free survival were 12% (95% CI 1% to 40%) and 14% (95% CI 1% to 46%), respectively. Amputation-free survival was 74% (95% CI 30% to 93%) at the 1-year interval and 40% at the 2-year interval (95% CI 7% to 73%). At the final follow-up interval, four patients had undergone amputations and four were being administered chronic antifungal suppression.

CONCLUSION

Megaprosthesis fungal PJIs are rare but devastating. Arthroplasty surgeons should consider treatment efficacy, which appears to be low across surgical strategies, and the patient's capacity to withstand it. A lower decision threshold for performing amputation may be considered in patients who require rapid infection control to initiate immunosuppressive treatments. Future studies should aim to compare the surgical and clinical outcomes of fungal PJIs with those of other etiologies while controlling for potential variables. Efforts should be made to establish multi-institutional collaborations to achieve larger study samples.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

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.

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.

Hip Arthroplasty Outcomes in Patients with Metastatic Bone Disease

Background/Objective

The hip is a common location for metastatic bone disease (MBD) and surgical intervention is often indicated to relieve pain and improve function. MBD of the hip is usually treated with hemiarthroplasty or with total hip arthroplasty if there are acetabular lesions. As treatment for metastatic disease evolves and patients may expect to live longer after diagnosis, further evaluation of the complications and functional outcomes associated with hip arthroplasty for MBD are necessary.

Methods

This was a retrospective review of patients who underwent hip arthroplasty for MBD at a single institution between 2007 and 2021. Outcomes included rates of reoperation, complications, and overall survival.

Results

Ninety-three cases in 91 patients were included. Total hip arthroplasty (THA) was performed in 52 cases (55.9%), hemiarthroplasty in 15 (16.1%), and complex arthroplasty, including proximal femur replacement or THA with complex acetabular reconstruction, was performed in 26 (28%). There were 11 reoperations in five patients and six dislocations. Median survival was 10.4 months and one-year overall survival was 53.3%. There was a significant increase in the proportion of patients who were able to ambulate independently (35.2% vs 17.6%; p=0.02) and a significant decrease in patients confined to a wheelchair (18.7% vs 3.3%; p=0.045) after surgery.

Conclusions

Hip arthroplasty for MBD leads to relatively low rates of complications and reoperations in this population known to have high postoperative morbidity and mortality. Hip arthroplasty provides the majority of MBD patients with a durable reconstruction that exceeds their lifespan and enables them to return to an acceptable level of function.

Synthetic Ligament-Assisted Functional Soft-Tissue Reconstruction in Tumor-Related Proximal Femoral Replacements

BACKGROUND

Soft-tissue functional reconstruction is important for restoring hip function in proximal femoral replacement for tumor resection. This study evaluated the functional outcome and postoperative complications of a specific synthetic ligament for soft-tissue functional reconstruction in proximal femoral replacement for tumor resection.

METHODS

This cohort included 80 patients (40 men and 40 women, mean age, 40 years (range, 10 to 79)) who had benign invasive tumors (n = 13), primary malignant bone tumors (n = 40), or bone metastases (n = 27). Patients' medical records, imaging files, surgical details, and postoperative pathological diagnoses were collected. Tumor staging was performed with the Enneking staging criteria. Lower limb and hip functions were assessed using the Musculoskeletal Tumor Society scoring system and Harris Hip score, respectively.

RESULTS

Mean postoperative Musculoskeletal Tumor Society and Harris Hip scores were 27 (range, 24 to 30) and 90 (range, 76 to 97), respectively, indicating satisfactory range of motion and stability. Trendelenburg gait was observed in 3 osteosarcoma patients (3.8%), and 6 patients showed unequal lower-limb lengths. Reoperations occurred in 5 cases, including 3 cases of deep vein thromboses and 1 case each of giant cell granuloma and periprosthetic infection. There were 27 patients who had bone metastases who did not require reoperation.

CONCLUSIONS

The synthetic ligament reconstruction of the hip with proximal femoral replacement for tumor resection was associated with improved outcomes. Its implementation exhibits the potential to reduce postoperative incidences of hip dislocation and periprostheses infection, thereby warranting its prospective clinical application.

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

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

Rotationplasty type BIIIb as an effective alternative to limb salvage procedure in adults: Two case reports

BACKGROUND

Rotationplasty is often performed for malignant tumors, but type BIIIb rotationplasty is rarely reported, and there needs to be more evidence of the procedure and treatment. The purpose of this case study was to report a new direction in the use of type BIIIb rotationplasty in treating patients with limb salvage and long-term non-healing infections.

CASE SUMMARY

Case 1: A 47-year-old man underwent radiotherapy for hemangioendothelioma in his left thigh, resulting in a femoral fracture. Despite the use of plates, intramedullary nailing, and external fixators, the femoral bone failed to unite due to infectious nonunion. Multiple operations were unable to control the infection, leaving the patient immobile. We performed a modified tibia-pelvic-constrained hip rotationplasty, utilizing a constrained prosthetic hip between the tibia and pelvis following a femur resection. Two years post-surgery, the patient was able to walk with the prosthetic device without any signs of recurring infection. The corresponding functional scores were 72 points for the Musculoskeletal Tumor Society (MSTS), 53 for the Functional Mobility Assessment (FMA), 93 for the Toronto Extremity Salvage Score (TESS), and 56 for the MOS 36-item short form health survey (SF-36). Case 2: A 59-year-old woman presented with liposarcoma in her left thigh. Magnetic resonance imaging revealed tumors in the medial, anterior, and posterior femur muscles, encircling the femoral vessels and nerves. Fortunately, there were no symptoms of sciatic dysfunction, and the tumor had not invaded the sciatic nucleus. After one year of follow-up, the patient expressed satisfaction with limb preservation post-type BIIIb rotationplasty. The corresponding functional scores were 63 points for the MSTS, 47 for the FMA, 88 for the TESS, and 52 for the SF-36.

CONCLUSION

Our study suggests that type BIIIb rotationplasty may be an alternative to amputation in patients with incurable infections. For malignant tumors of the lower extremities without invasion of the sciatic nerve, type BIIIb rotationplasty remains an excellent alternative to amputation. This surgical method may prevent amputation, improve functional outcomes, and facilitate biological reconstruction.

Proximal femoral tumor resection followed by joint prosthesis replacement: a systematic review and meta-analysis

BACKGROUND

This study aimed to determine the prognostic outcome of hip joint replacement after resection of proximal femoral tumors by reviewing original studies.

METHODS

Two researchers independently searched PubMed, Embase, Cochrane Library, and Web of Science databases from inception to July 17, 2022. Then, the literature was screened by inclusion criteria. The basic information, primary outcomes, and secondary outcomes were extracted for weighted combined analysis. The quality of the included literature was evaluated using the Newcastle-Ottawa scale.

RESULTS

Twenty-four retrospective cohort studies comprising 2081 patients were included. The limb salvage rate was 98%. The survival rates at 1, 2, 3, 4, and 5 years were 80, 72, 65, 64, and 55% for patients with primary tumors and the rate at 1, 2, 3, 4, and 5 years were 44, 25, 17, 14, and 11% for patients with bone metastases, respectively.

CONCLUSION

As chemotherapy and radiotherapy treatment progressed, joint reconstruction after proximal femoral tumor resection improved patients' function and quality of life.

Prophylactic antibiotics for massive endoprostheses in orthopaedic oncology

The recently published Prophylactic Antibiotic Regimens In Tumor Surgery (PARITY) trial found no benefit in extending antibiotic prophylaxis from 24 hours to five days after endoprosthetic reconstruction for lower limb bone tumours. PARITY is the first randomized controlled trial in orthopaedic oncology and is a huge step forward in understanding antibiotic prophylaxis. However, significant gaps remain, including questions around antibiotic choice, particularly in the UK, where cephalosporins are avoided due to concerns of Clostridioides difficile infection. We present a review of the evidence for antibiotic choice, dosing, and timing, and a brief description of PARITY, its implication for practice, and the remaining gaps in our understanding.

ROLE OF INCISIONAL VACUUM THERAPY IN ENDOPROSTHETIC BONE RECONSTRUCTION SURGERY

Reconstructive surgery with endoprostheses is the chosen method for treating bone malignancies. Postoperative infections are frequent complications, and their treatment involves prolonged hospital stays and antibiotic therapy. Among the advancements aimed at reducing the rate of postoperative infection, the use of incisional negative pressure therapy (iNPT) has shown promising results, with no reports in the literature regarding its use in patients with such conditions.

Objective

To evaluate the effectiveness of iNPT in reducing postoperative complications in surgeries for resection of bone tumors associated with modular endoprosthesis reconstruction.

Methods

Retrospective case series of 16 patients diagnosed with osteosarcoma, who underwent resection and reconstruction with endoprosthesis associated with iNPT during the postoperative period. Follow-up was performed for a period of six months, and the evaluated outcomes were the incidence of postoperative infection and complications of the surgical wound.

Results

The use of iNPT for a postoperative period of seven days resulted in only three (18.7%) cases of postoperative infection. No cases of wound dehiscence, seroma formation, or hematoma at the surgical site were observed.

Conclusion

The rate of surgical wound complications in our case series is lower than that reported in most of the literature, and iNPT appears to be an efficient way to reduce the rate of local complications in reconstructive surgeries with endoprosthesis after resection of bone malignancies. Level of Evidence III, Retrospective Study.

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.

Risk factors for recurrent infection in the surgical treatment of infected massive endoprostheses implanted for musculoskeletal tumours

BACKGROUND

Infection is a devastating complication of endoprosthetic replacement (EPR) in orthopaedic oncology. Surgical treatments include debridement and/or one- or two-stage exchange. This study aims to determine the infection-free survival after surgical treatment for first and recurrent EPR infections and identify the risk factors associated with infection recurrence.

METHODS

This single-centre cohort study included all patients with primary bone sarcomas or metastatic bone disease treated for infected EPR between 2010 and 2020. Variables included soft tissue status using McPherson classification, tumour type, silver coating, chemotherapy, previous surgery and microorganisms identified. Data for all previous infections were collected. Survival analysis, with time to recurrent infection following surgical treatment, was calculated at 1, 2 and 4 years. Cox regression analysis was used to assess the influence of different variables on recurrent infection.

RESULTS

The cohort included 99 patients with a median age of 44 years (29-58 IQR) at the time of surgical treatment. The most common diagnoses were osteosarcoma and chondrosarcoma. One hundred and thirty-three surgical treatments for first or subsequent infections were performed. At 2 years of follow-up, overall success rates were as follows: two-stage exchange 55.3%, one-stage exchange 45.5%, DAIR with an exchange of modular components 44.6% and DAIR without exchange of modular components 24.7%. Fifty-one (52%) patients were infection-free at the most recent follow-up. Of the remaining 48 patients, 27 (27%) were on antibiotic suppression and 21 (21%) had undergone amputation. Significant risk factors for recurrent infection were the type of surgical treatment, with debridement alone as the highest risk (HR 4.75: 95%CI 2.43-9.30; P < 0.001); significantly compromised soft tissue status (HR 4.41: 95%CI 2.18-8.92; P = 0.001); and infections due to Enterococcus spp.. (HR 7.31: 95%CI 2.73-19.52); P = 0.01).

CONCLUSIONS

Two-stage exchange with complete removal of all components where feasible is associated with the lowest risk of recurrent infection. Poor soft tissues and enterococcal infections are associated with higher risks of recurrent infection. Treatment demands an appropriate multidisciplinary approach. Patients should be counselled appropriately about the risk of recurrent infection before embarking on complex treatment.

Salvage of limb salvage in oncological reconstructions of the lower limb with megaprosthesis: how much to push the boundaries?

INTRODUCTION

Megaprosthesis represent the most commonly used limb salvage method after musculoskeletal tumor resections. Nevertheless, they are burdened by high complication rate, requiring several surgical revisions and eventually limb amputation. The aims of this study were to evaluate the effect of rescuing the limb with subsequent revisions on complication rates (a), incidence of amputations (b), and whether complications reduce functional outcome after the first surgical revision (c).

MATERIALS AND METHODS

We retrospectively reviewed 444 lower limb megaprosthesis implanted for primary musculoskeletal tumors or metastatic lesions, from February 2000 to November 2017. 59 patients received at least one revision megaprosthesis surgery. MSTS score was used to assess final functional results. Complication-revision-amputation free survival rates were calculated both at 5 and 10 years of follow-up.

RESULTS

Complication free survival, revision free survival and amputation free survival at 10 years were 47% and 53%, 61% and 67%, 90% and 86% among all 444 patients and the group of 59 revised patients, respectively. The incidence of further complications after the first complication was 26% in the group treated with no subsequent revision surgeries and 51% in the group with at least one revision surgery. We found a trend of inverse linear relationship between the number of complications needing subsequent revision surgeries and the final MSTS.

CONCLUSION

The number of further revision surgeries after limb salvage with megaprosthesis increases the incidence of complications. Repeated surgical revisions, in particular after infection, increase the amputation rate. The most frequent causes of failure were structural failures and infections. MSTS score was superior for patients undergoing limb salvage than amputees. However, MSTS progressively decreased with multiple revisions becoming inferior to the functional score of an amputated patient.

Double vascularized fibula growth plate transfer for the reconstruction of long segmental tibia in pediatric patients: Report of three cases

Osteosarcoma is a common bone tumor for pediatric patients that has a complex treatment including chemotherapy and radical surgical resection. There are few functional leg reconstruction possibilities described in the literature for pediatric patients due to limited growth potential. The aim of this report is to show long-term results using double vascularized growth plate flaps for the long segmental tibial reconstruction in growing children with satisfactory functionality and preserved limb growth without the use of permanent foreign materials. Three patients with sarcoma in the proximal part of the tibial bone were treated with complex therapy that included preoperative chemotherapy, radical resection of proximal metaepiphysis with tibial growth plate and half of the diaphysis and transplantation of double fibula growth plate flaps-the pedicled ipsilateral and the contralateral as a microvascular flap. The first patient, a male, 13 year with periosteal sarcoma, underwent 17 cm tibial resection with transplantation of the ipsilateral fibula 20 cm and contralateral fibula 20.1 cm, and continued follow-up for 6 years. The second patient, a male, 6 years of age with osteosarcoma, had 14 cm tibial resection with 16 cm ipsilateral and 16.1 cm contralateral fibular transplantation, continued follow-up for 5 years. The third patient, a female, 12 years of age with osteosarcoma, underwent 14 cm tibial resection with 15.4 cm ipsilateral and 15.9 cm contralateral fibular transplantation, and current follow-up of 1 year. Double fibular growth plate transfer is limb-sparing method for a proximal tibial reconstruction with natural growth potential for the pediatric patients.

A Retrospective Cohort Analysis of Limb Salvage Surgery Using Mega Prosthesis in Bone Tumours at a Tertiary Care Centre in Eastern India

Background

The method known as "limb salvage surgery" (LSS) aids in the removal of extremity tumours, and reconstruction is completed with satisfactory oncologic, functional, and cosmetic outcomes. Oncologic clearance is given first priority, followed by functional outcomes. Worldwide, the trend has already shifted away from amputations and toward limb salvage surgery for eligible patients due to efficient chemotherapy regimens, improved imaging techniques, precise administration of enhanced radiation, better reconstructive choices, and developments in bio-engineering. The purpose of the present study was to determine the clinicopathological characteristics, surgical techniques, functional outcome, and prognostic factors of limb salvage surgery performed using mega prosthesis in primary malignant or benign resectable tumours.

Methods

Our retrospective cohort study was carried out over a period of two years and included 28 patients who received care for bone tumours. The data gathered comprised the demographic profile, clinical characteristics, histological characteristics, treatments given, functional results, and survival. LSS was performed on all patients by orthopaedics oncologists trained in the surgical oncology department. Following surgery, during the first two years, patients were examined at every three-month interval, then every six months until the fifth year, and then once a year after that. The Kaplan-Meier method was utilized to determine the median follow-up and recurrence-free survival (RFS).

Results

In our study, the mean age of study subjects was 30.0±10.9 years. Almost all of the subjects included in the study had lower limb bone tumours (96.4%). The most common site for the tumour was the distal femur (57.1%) followed by the proximal femur (32.2%). The most common type of benign tumour was giant cell tumour (GCT) (53.6%), including recurrences of giant cell tumour (GCT), and among malignant tumours, osteosarcoma was the most common (25.0%). The mean surgical resection of bone in limb salvage surgery was 125.2±24.2 mm. The most common post-operative complication was leg length discrepancy (LLD) among 25.0% of subjects, which was managed by shoe raise. The overall mean musculoskeletal tumour society (MTSS) score after LSS was 25.0±4.3. Using the Kaplan-Meier method analysis, we found that relapse-free survival was 83.7% among enrolled subjects at a median follow-up period of 80 months.

Conclusion

It can be difficult to surgically treat patients who have malignant bone tumours. In limb-sparing surgery for bone tumours, the modular segmental-replacement system prosthesis that we preferred produced satisfactory results in terms of tumour control and limb function. To get good long-term results, the case selection must be appropriate.

Revision surgeries for tumor endoprostheses around the knee joint: a mid-long-term follow-up of 20 cases

Background

Tumor endoprostheses of the knee joint after limb salvage surgery is associated with high rates of complications, which has introduced great challenges to a delayed revision surgery. The aim of the study was to summarize the failures, functional outcomes and prosthetic survival in revision tumor endoprostheses of the knee joint.

Methods

The clinical data of 20 patients with malignant tumors who received prosthetic revisions after limb salvage surgery from January, 2000 until January, 2018 were retrospectively reviewed. The cohort was constituted of 11 male and 9 female patients with a mean age of 34.1 years (range, 16 to 66 years). Infection cases received two-stage revisions after removing prostheses initially, while all other cases received one-stage revisions. Revision reasons and complications were well documented and analyzed.

Results

All patients received complete follow-up with a mean time of 64.7 months (range, 27 to 155 months). A total of 6 (6/20, 30.0%) patients experienced a second complication after revision surgery, of whom, one patient with deep infection experienced repeated infections after prosthetic revision and received amputation surgery; one patient revised of prosthetic fracture experienced an infection and received a second-stage infection revision; one case revised of prosthetic loosening had deep infection receiving anti-infective therapy with prostheses still in position; one case having wound complication healed after receiving two times of debridement surgery; one MBGCT patient experienced a second aseptic loosening 6 years after the initial loosening thus undergoing a second revision; a recurrent osteosarcoma patient died of pulmonary metastasis 3 years after revision surgery. Kaplan-Meier survival curve indicated a 5-year survival rate of initial prostheses was 75%. The Musculoskeletal Tumor Society (MSTS-93) score [20.9 (range, 15 to 27 scores)] at 1 year after revision surgeries was significantly improved (p < 0.001) when compared with the score [17.2 (range, 13 to 21 scores)] before revisions.

Conclusion

Prosthetic mechanical problems, aseptic loosening and infections were primary reasons for revisions after tumor endoprostheses of the knee joint. Although revision surgeries were complicated while still associated with high risk of failure, which remains the remedy strategy for limb salvage and functional recovery in those patients.

Survivorship, complications, and outcomes following distal femoral arthroplasty for non-neoplastic indications

Aims

Endoprosthetic reconstruction with a distal femoral arthroplasty (DFA) can be used to treat distal femoral bone loss from oncological and non-oncological causes. This study reports the short-term implant survivorship, complications, and risk factors for patients who underwent DFA for non-neoplastic indications.

Methods

We performed a retrospective review of 75 patients from a single institution who underwent DFA for non-neoplastic indications, including aseptic loosening or mechanical failure of a previous prosthesis (n = 25), periprosthetic joint infection (PJI) (n = 23), and native or periprosthetic distal femur fracture or nonunion (n = 27). Patients with less than 24 months’ follow-up were excluded. We collected patient demographic data, complications, and reoperations. Reoperation for implant failure was used to calculate implant survivorship.

Results

Overall one- and five-year implant survivorship was 87% and 76%, respectively. By indication for DFA, mechanical failure had one- and five-year implant survivorship of 92% and 68%, PJI of 91% and 72%, and distal femur fracture/nonunion of 78% and 70% (p = 0.618). A total of 37 patients (49%) experienced complications and 27 patients (36%) required one or more reoperation. PJI (n = 16, 21%), aseptic loosening (n = 9, 12%), and wound complications (n = 8, 11%) were the most common complications. Component revision (n = 10, 13.3%) and single-stage exchange for PJI (n = 9, 12.0 %) were the most common reoperations. Only younger age was significantly associated with increased complications (mean 67 years (SD 9.1)) with complication vs 71 years (SD 9.9) without complication; p = 0.048).

Conclusion

DFA is a viable option for distal femoral bone loss from a range of non-oncological causes, demonstrating acceptable short-term survivorship but with high overall complication rates.

Cite this article: Bone Jt Open 2022;3(3):173–181.

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.

Risk Factors Related to Poor Outcomes in the Treatment of Non-conventional Periprosthetic Infection

Objectives  To identify the main risk factors related to poor outcomes after the treatment for periprosthetic infection.

Materials and Methods  Medical records from 109 patients who underwent non-conventional endoprosthesis surgeries (primary and revision procedures) from January 1, 2007, to December 31, 2018, were retrospectively evaluated. In total, 15 patients diagnosed with periprosthetic infection were eligible to participate in the study. Variables including gender, age at diagnosis, affected bone, surgery duration, white blood cell (WBC) count before endoprosthesis placement, urinary tract infection during the first postoperative year, and time elapsed from endoprosthesis placement to infection diagnosis were related to outcomes using the Fisher exact test (for the bicategorical variables) or analysis of variance (ANOVA, for the tricategorical variables). The mean times from diagnosis to final outcome were compared using the Student t -test.

Results  These risk factors did not show a statistically significant correlation with the outcomes. The data revealed a trend towards a difference between the mean time for the onset of infection and the final outcome. Due to the limited sample, we believe that studies with larger cohorts can prove this trend.

Conclusion  We identified that the time from endoprosthesis placement to the onset of the symptoms of infection tends to be related to the outcome and evolution of the patient evolution during the treatment for periprosthetic infection. Although apparently correlated, other associated factors were not statistically linked to poor treatment outcomes.

Early Post-Traumatic Van Nes Rotationplasty After an Open Femur Fracture With a Necrotizing Soft-Tissue Infection: A Case Report

CASE

A 26-year-old man presented after an automobile versus pedestrian accident with a Type IIIA open femur fracture complicated by a necrotizing soft-tissue infection (NSTI) with significant bone loss. Multiple limb-preserving operations failed, including the placement of a plate-assisted, motorized lengthening intramedullary nail with a chimeric free flap. We describe the patient's successful definitive treatment with a Van Nes rotationplasty (VNR). The patient currently ambulates independently with a prosthesis and is without recurrent infection after 3 years of follow-up.

CONCLUSION

VNR is a potential strategy to avoid transfemoral amputation or hip disarticulation in open femur fractures complicated by NSTI.

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.

Straightplasty, a Limb Salvage Procedure in Malignant and Aggressive Bone Tumors of Lower Extremities: A Retrospective Analysis

Introduction The management of malignant bone tumors of lower extremities involves various modalities, which depend not only on local and systemic affection but are also affected by psychosocial factors. The purpose of this study was to evaluate functional and psychosocial outcomes in patients with non-salvageable lower limbs having malignant or aggressive benign bone tumors of distal thighs, who were treated with a technique called straightplasty. Material and methods We enrolled 20 patients of non-salvageable primary malignant or aggressive benign bone tumors around the knee. Out of these, 15 patients were followed and evaluated in view of functional and clinical outcomes having a minimum of 22 months of final follow-up. Results A total of 15 patients (8 males, 7 females) having a non-salvageable lower limb with a mean age of 20.53 years (range, 12 to 45 years), who were managed with straightplasty and followed for a mean duration of 31.73 months (range 22 to 72 months) were evaluated clinico-radiologically, and the functional outcomes were measured by Enneking' s method. The surgical procedure is simple and better in terms of functional outcomes than other procedures described in the literature, while it is observed as psychosocially more acceptable in developing nations, especially in the Indian context. Most of the parameters are comparable to rotationplasty and above-knee amputation, whereas it is less technically demanding and satisfying due to the straight limb rather than the rotated leg in rotationplasty. Conclusion We recommend straightplasty as an alternative to rotationplasty or above-knee amputation in patients having malignant or aggressive benign tumors around the knee joint and where limb salvage procedures are not feasible.

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.

TiAl6V4 Alloy Surface Modifications and Their Impact on Biofilm Development of S. aureus and S. epidermidis

One of the most serious complications following joint replacement surgeries are periprosthetic infections (PIs) arising from the adhesion of bacteria to the artificial joint. Various types of titanium-aluminum-vanadium (TiAl6V4) alloy surface modifications (coatings with silver (Ag), titanium nitride (TiN), pure titanium (cpTi), combinations of cpTi and hydroxyapatite (HA), combinations of cpTi and tricalcium phosphate (TCP), and a rough-blasted surface of TiAl6V4) have been investigated to assess their effects on biofilm development. Biofilms were grown, collected, and analyzed after 48 h to measure their protein and glucose content and the cell viability. Biofilm-associated genes were also monitored after 48 h of development. There was a distinct difference in the development of staphylococcal biofilms on the surfaces of the different types of alloy. According to the findings of this study, the base alloy TiAl6V4 and the TiN-coated surface are the most promising materials for biofilm reduction. Rough surfaces are most favorable when it comes to bacterial infections because they allow an easy attachment of pathogenic organisms. Of all rough surfaces tested, rough-blasted TiAl6V4 was the most favorable as an implantation material; all the other rough surfaces showed more distinct signs of inducing the development of biofilms which displayed higher protein and polysaccharide contents. These results are supported by RT-qPCR measurements of biofilm associated genes for Staphylococcus aureus (icaA, icaC, fnbA, fnbB, clfB, atl) and Staphylococcus epidermidis (atle, aap).

Nonmechanical Revision Indications Portend Repeat Limb-Salvage Failure Following Total Femoral Replacement

BACKGROUND

There is scant evidence to guide decision-making for patients considering total femoral replacement (TFR). We aimed to identify the indication, patient, disease, and surgical technique-related factors associated with failure. We hypothesized that failure occurs more frequently in the setting of revision surgical procedures, with infection as the predominant failure mode.

METHODS

We performed a retrospective cohort study of patients receiving total femoral endoprostheses for oncological and revision arthroplasty indications; 166 patients met these criteria. Our primary independent variable of interest was TFR for a revision indication (arthroplasty or limb salvage); the primary outcome was failure. Analyses were performed for patient variables (age, sex, diagnosis group, indication), implant variables (model, decade, length, materials), and treatment variables. We analyzed TFR failures with respect to patient factors, operative technique, and time to failure. We conducted bivariate logistic regressions predicting failure and used a multivariate model containing variables showing bivariate associations with failure.

RESULTS

Forty-four patients (27%) had treatment failure. Failure occurred in 24 (23%) of 105 primary TFRs and in 20 (33%) of 61 revision TFRs; the difference was not significant (p = 0.134) in bivariate analysis but was significant (p = 0.044) in multivariate analysis. The mean age at the time of TFR was 37 years in the primary group and 51 years in the revision group (p = 0.0006). Of the patients who had mechanical failure, none had reoccurrence of their original failure mode, whereas all 8 patients from the nonmechanical cohort had reoccurrence of the original failure mode; this difference was significant (p = 0.0001).

CONCLUSIONS

TFR has a high failure rate and a propensity for deep infection, especially in the setting of revision indications and prior infection. All failed TFRs performed for revision indications for infection or local recurrence failed by reoccurrence of the original failure mode and resulted in amputation.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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.

Efficacy of antimicrobial coated orthopaedic implants on the prevention of periprosthetic infections: a systematic review and meta-analysis

Introduction: Implant-associated infections are a major problem in orthopaedic surgery. Local delivery systems of antimicrobial agents on the implant surface have attracted great interest recently. The purpose of this study was to identify antimicrobial coatings currently used in clinical practice, examining their safety and effectiveness in reducing post-operative infection rates.

Materials and Methods: A systematic review was conducted in four databases (Medline, Embase, Cochrane, Cinahl) according to the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) guidelines up to December 2019, using the key words “orthopaedic implant coated”, “coated implant infection”, “silver coating ” and “antibiotic coating”.

Results: Seven articles involving 1307 patients (561 with coated implants and 746 controls who were not) comparing the incidence of periprosthetic infections after the application of internal fracture fixation, total arthroplasties and endoprostheses were evaluated. Three different coating technologies were identified: gentamicin coating for tibia nail and total arthroplasties; silver technology and povidone-iodine coating for tumour endoprostheses and titanium implants. Meta-analysis demonstrated that patients who were treated with antimicrobial coated implants presented lower infection rates compared to controls over the seven studies (Q = 6.1232, I2 = 0.00, 95% CI: 1.717 to 4.986, OR: 2.926, Z= 3.949, p<0.001). Subgroup statistical analysis revealed that each coating technique was effective in the prevention of periprosthetic infections (Q = 9.2606, I2 = 78.40%, 95% CI: 1.401 to 4.070, OR: 2.388, Z= 3.200, p<0.001).

Conclusion: All technologies were reported to have good biocompatibility and were effective in the reduction of post-operative peri-prosthetic infection rates.

Management of infected extremity endoprostheses: a systematic review

BACKGROUND

Endoprosthetic reconstructions have become increasingly common in the setting of significant bone loss. Indications include revision arthroplasty, trauma, and reconstruction in the setting of primary malignancies or bony metastases. Although the use of endoprostheses has several advantages, they carry a high risk of infection. The purpose of this review is to determine the success rates of surgical management of infected endoprostheses.

METHODS

The authors searched databases for relevant studies and screened in duplicate. Data extracted included overall infection rate, timing of infection, follow-up, isolated pathogen and operative treatment strategy, and subsequent failure rate. The overall quality of the evidence with the Methodological Index for non-randomized studies criteria.

RESULTS

A total of 16 studies and 647 patients met the inclusion criteria. 400 patients had operative management and reported outcomes. Failure rates of patients undergoing debridement, antibiotics, and implant retention (DAIR) were 55.1%. Failure rates of patients who underwent one-stage revision were 45.5%. Failure rates of patients undergoing two-stage revision were 27.3%. Failure occurred at 31.4 months (range, 0-228) postoperatively.

CONCLUSIONS

Rates of periprosthetic joint infection remain high in endoprosthetic reconstructions. Although DAIR procedures were found to have a low success rate, they remain a reasonable option in acute infections given the morbidity of staged revisions. There is a lack of comparative data in the current literature and the heterogeneity and low level of evidence does not allow for between group comparisons of results.

Fixed-hinge cemented modular implants: An effective reconstruction technique following primary distal femoral bone tumor resection. A 136-case multicenter series

BACKGROUND

Reconstruction by endoprosthesis is widespread after bone tumor resection. The design and type of fixation and of hinge remain a matter of debate. The aim of the present study was to assess survival, complications and functional results in a homogeneous series of adult patients undergoing bone defect reconstruction following distal femoral tumor resection, using a single model of fixed-hinge cemented endoprosthesis, at a minimum 5 years' follow-up.

HYPOTHESIS

The study hypotheses were that loosening and infection are the main causes of failure, and that this type of reconstruction is reliable following distal femoral resection.

PATIENTS AND METHODS

All patients aged over 17 years undergoing reconstruction using the Stanmore Mets® fixed-hinge cemented modular endoprosthesis following distal femoral resection for primary bone tumor in 4 French reference centers between 2004 and 2013 were included. Epidemiological data, MSTS functional score, clinical and radiological examination results, complications and survival with types of failure according to the Henderson classification were assessed.

RESULTS

One hundred and thirty-six patients (68 male, 68 female; mean age, 41.2 years [range, 17-77 years]) were included. Mean follow-up was 81 months [range, 61-134 months]. Thirty-two patients (38%) experienced a total 67 complications requiring surgical revision: mainly infection (n=28) or mechanical failure (n=26). Overall implant survival was 78% at 5 years. There were 30 implant failures on the Henderson classification. Mean MSTS score was 82%.

DISCUSSION

The present results are comparable to those of the literature and for other types of reconstruction. Recent meta-analyses suggest that type of hinge and of stem fixation have little effect on implant survival. International comparative studies are needed to determine the exact role of each type of reconstruction according to the patient profile.

LEVEL OF EVIDENCE

IV, multicenter retrospective series.

[Risk factors and management strategies for early and late infections following reconstruction with special tumour endoprostheses]

BACKGROUND

Periprosthetic joint infection (PJI) of megaprostheses occur in about 10% of all cases. The criteria for PJI are defined by the "Musculoskleletal Infection Society" (MSIS) and apply to both primary arthroplasty and megaprostheses.

MANAGEMENT

The management strategies of PJI in megaprostheses are dependent on the duration of infection and the maturity of the bacterial biofilm. Implant retention with an exchange of the mobile components is only possible in the presence of an immature biofilm. In the presence of a mature biofilm, a one- or two-stage exchange must be performed. A complete exchange of all endoprosthetic components should be performed, if possible, since a partial retention of isolated components results in inferior treatment success rates.

RESULTS

The highest success rates are achievable with two-stage exchanges. Multiple risk factors such as skin necrosis, postoperative haematoma, prolonged wound secretion and operative times ≥ 2.5 h are risk factors for the development of PJI in megaprostheses. Knowledge regarding these risk factors allows for an identification of high-risk patients and early management of PJI.

[Complication management following resection and reconstruction of the upper limbs and shoulder girdle]

BACKGROUND

Sarcomas of the upper limbs commonly affect the proximal humerus or scapula. Complications after tumor resection and reconstruction are rare but cannot be neglected, particularly after tumor endoprosthetic reconstructions.

MATERIALS AND METHODS

The most common complications after resection of sarcomas of the upper limbs and shoulder girdle are described, and current knowledge regarding complication management is presented. Additionally, a selective literature search was performed, incorporating personal experiences.

RESULTS

Wound healing disorders and infections after tumor resection without specific reconstruction (clavicle resection, scapulectomy) usually respond well to conservative or surgical treatment. However, periprosthetic infections after reconstruction using a megaendoprosthesis constitute a severe and frequent complication, with an incidence of 5-10%. Two-stage implant replacement still represents the gold standard, although in selected cases, one-stage revision with retention of the prosthetic stem appears warranted. Secondary amputation as a result of periprosthetic infection is rare compared to the situation with infections of the lower limb. Mechanical complications necessitating surgical revision are mostly limited to joint dislocation after inverse total shoulder replacement (TSR). (Sub)luxation in anatomic TSR can be tolerated provided there is no tendency toward perforation of the skin in a asymptomatic patient. Biological reconstructions are most often indicated for reconstruction of intercalary defects of the humerus, and revision is necessitated most frequently by mechanical complications. Despite multiple surgical revisions, stable reconstructions and limb salvage can usually be achieved in the upper limb.

What is the Likelihood That Tumor Endoprostheses Will Experience a Second Complication After First Revision in Patients With Primary Malignant Bone Tumors And What Are Potential Risk Factors?

BACKGROUND

Endoprosthetic reconstruction of massive bone defects has become the reconstruction method of choice after limb-sparing resection of primary malignant tumors of the long bones. Given the improved survival rates of patients with extremity bone sarcomas, an increasing number of patients survive but have prosthetic complications over time. Several studies have reported on the outcome of first endoprosthetic complications. However, no comprehensive data, to our knowledge, are available on the likelihood of an additional complication and the associated risk factors, despite the impact of this issue on the affected patients.

QUESTIONS/PURPOSES

(1) What are the types and timing of complications and the implant survivorship free from revision after the first complication? (2) Does survivorship free from repeat revision for a second complication differ by anatomic sites? (3) Is the type of first complication associated with the risk or the type of a second complication? (4) Are patient-, tumor-, and treatment-related factors associated with a higher likelihood of repeat revision?

METHODS

Between 1993 and 2015, 817 patients underwent megaprosthetic reconstruction after resection of a tumor in the long bones with a single design of a megaprosthetic system. No other prosthetic system was used during the study period. Of those, 75% (616 of 817) had a bone sarcoma. Seventeen patients (3%) had a follow-up of less than 6 months, 4.5% (27 of 599) died with the implant intact before 6 months and 43% (260 of 599 patients) underwent revision. Forty-three percent of patients (260 of 599) experienced a first prosthetic complication during the follow-up period. Ten percent of patients (26 of 260) underwent amputation after the first complication and were excluded from further analysis. Second complications were classified using the classification of Henderson et al. to categorize surgical results. Briefly, this system categorizes complications as wound dehiscence (Type 1); aseptic loosening (Type 2); implant fractures or breakage and periprosthetic fracture (Type 3); infection (Type 4); and tumor progression (Type 5). Implant survival curves were calculated with the Kaplan-Meier method and compared using the log-rank test. Hazard ratios (HR) were estimated with their respective 95% CIs in multivariate Cox regression models.

RESULTS

A second complication occurred in 49% of patients (115 of 234) after a median of 17 months (interquartile range [IQR] 5 to 48) after the surgery for the first complication. The time to complication did not differ between the first (median 16 months; IQR 5 to 57) and second complication (median 17 months; IQR 5 to 48; p = 0.976). The implant survivorship free from revision surgery for a second complication was 69% (95% CI 63 to 76) at 2 years and 46% (95% CI 38 to 53) at 5 years. The most common mode of second complication was infection 39% (45 of 115), followed by structural complications with 35% (40 of 115). Total bone and total knee reconstructions had a reduced survivorship free from revision surgery for a second complication at 5 years (HR 2.072 [95% CI 1.066 to 3.856]; p = 0.031) compared with single joint replacements. With the numbers we had, we could not show a difference between the survivorship free of revision for a second complication based on the type of the first complication (HR 0.74 [95% CI 0.215 to 2.546]; p = 0.535). We did not detect an association between total reconstruction length, patient BMI, and patient age and survivorship free from revision for a second complication. Patients had a higher risk of second complications after postoperative radiotherapy (HR 1.849 [95% CI 1.092 to 3.132]; p = 0.022) but not after preoperative radiotherapy (HR 1.174 [95% CI 0.505 to 2.728]; p = 0.709). Patients with diabetes at the time of initial surgery had a reduced survivorship free from revision for a second complication (HR 4.868 [95% CI 1.497 to 15.823]; p = 0.009).

CONCLUSIONS

Patients who undergo revision to treat a first megaprosthetic complication must be counseled regarding the high risk of future complications. With second complications occurring relatively soon after the first revision, regular orthopaedic follow-up visits are advised. Preoperative rather than postoperative radiotherapy should be performed when possible. Future studies should evaluate the effectiveness of different approaches in treating complications considering implant survivorship free of revision for a second complication.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Rotational Tibio-Pelvic Constrained Hip Arthroplasty: A Surgical Technique: A Case Report

CASE

A 25-year-old man presented with chronic bone and soft tissue infection of the right thigh following resection and radiation of epithelioid sarcoma. Multiple revisions and debridement procedures had failed to control the infection and left him unable to ambulate. We describe a modified Van Nes rotationplasty using a constrained, prosthetic hip between the tibia and pelvis following femur resection. With 18 months of follow-up, the patient was able to walk with a prosthetic device without evidence of recurrent infection.

CONCLUSIONS

We report this rotationplasty as a potential approach to avoid hip disarticulation in cases requiring extensive debridement for incurable infection.

[Current results of tumour endoprosthetics in adolescents and adults]

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND AND OBJECTIVES

We investigated implant revision, implant failure, and amputation risk after limb-sparing bone tumor surgery using the Global Modular Replacement System (GMRS) tumor prosthesis in patients suffering from bone sarcomas (BS), giant cell tumors (GCT), or metastatic bone disease (MBD).

MATERIAL AND METHODS

A retrospective study of a nationwide consecutive cohort (n = 119, 47 [12-81] years, M/F = 65/54) having limb-sparing surgery and reconstruction using the GMRS tumor prosthesis due to bone tumors (BS/GCT/MBD = 70/8/41) from 2005 to 2013. Anatomical locations were as followed: distal femur (n = 49), proximal femur (n = 41), proximal tibia (n = 26), or total femur (n = 3). Kaplan-Meier survival analysis and competing risk analysis with death as a competing risk were used for statistical analysis.

RESULTS

For BS and GCT patients, 5-year patient survival was 72% (95% confidence interval [CI]: 59-85%) and for MBD 33% (95% CI: 19-48%). Thirty-two patients underwent revision surgery (5-year revision incidence 14%; 95% CI: 8-21%). Twelve patients had revision of bone-anchored parts (implant failure) with a 5-year revision incidence 6% (95% CI: 2-10%). Ten amputations were performed due to local relapse (n = 9) or recurrent infections (n = 1) with a 5-year incidence of amputation: 8% (95% CI: 3-13%).

CONCLUSIONS

We identified a low risk of revision and amputation when using the GMRS tumor prosthesis for limb-sparing bone tumor.

Multiflora and Gram-Negative Microorganisms Predominate in Infections Affecting Pelvic Endoprostheses Following Tumor Resection

BACKGROUND

Periprosthetic infections after pelvic reconstruction are common, with reported rates ranging from 11% to 53%. Management of these infections is troublesome, as they commonly necessitate multiple surgical interventions and implant removal. The epidemiology and outcomes of these infections are largely unknown. The aim of this study was to analyze the causative microorganisms and the clinical outcome of treatment in a series of patients with pelvic endoprostheses affected by infection following tumor resection.

METHODS

In this retrospective, multicenter cohort study, we identified all patients who developed an infection after endoprosthetic reconstruction in periacetabular tumor resection, between 2003 and 2017. The microorganisms that were isolated during the first debridement were recorded, as were the number of reoperations for ongoing infection, the antimicrobial treatment strategy, and the outcome of treatment.

RESULTS

In a series of 70 patients who underwent pelvic endoprosthetic reconstruction, 18 (26%) developed an infection. The type of pelvic resection according to the Enneking-Dunham classification was type P2-3 in 14 (78%) of these patients and type P2 in 4 (22%). Median follow-up was 66 months. Fourteen (78%) of the 18 patients with infection had a polymicrobial infection. Enterobacteriaceae were identified on culture for 12 (67%). Of a total 42 times that a microorganism was isolated, the identified pathogen was gram-negative in 26 instances (62%). Microorganisms associated with intestinal flora were identified 32 times (76%). At the time of latest follow-up, 9 (50%) of the patients had the original implant in situ. Of these, 2 had a fistula and another 2 were receiving suppressive antibiotic therapy. In the remaining 9 (50%) of the patients, the original implant had been removed. At the time of final follow-up, 3 of these had a second implant in situ. The remaining 6 patients had undergone no secondary reconstruction.

CONCLUSIONS

Infections that affect pelvic endoprostheses are predominantly polymicrobial and caused by gram-negative microorganisms, and may be associated with intestinal flora. This differs fundamentally from mono-bacterial gram-positive causes of conventional periprosthetic joint infections and may indicate a different pathogenesis. Our results suggest that prophylaxis and empiric treatment may need to be re-evaluated.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Uncemented, curved, short endoprosthesis stem for distal femoral reconstruction: early follow-up outcomes

Background

Uncemented endoprosthetic knee replacement has become a mainstream treatment for malignant tumours of the distal femur. Most femoral stems, however, are straight and therefore poorly fit the anteriorly bowed curvature of the femur. To address this issue, we used a short, curved, uncemented press-fit femoral stem and evaluated its short-term outcomes after reconstruction of the distal femur.

Methods

Forty-two patients underwent distal femur replacement using curved press-fit stem. To assess the interface, we measured the axial length of the press-fit area and the perpendicular distance of the radiolucent area between the stem and bone on digital images obtained using tomosynthesis with Shimadzu Metal Artefact Reduction Technology (T-SMART). Postoperative complications and oncological outcomes were monitored at each follow-up visit.

Results

Of the 42 patients enrolled in the study, two had cancer-related deaths and one had local tumour recurrence. The minimum follow-up time of the surviving patients was 24 months, with no incidence of aseptic loosening or mechanical failure of the prosthesis. The average effective contact length between the press-fit stem and bone was 74.0 mm, with nearly undetectable radiolucent gaps between the implant and the bone on medial-lateral and anteroposterior views.

Conclusions

Over the short term, uncemented, curved, short stem provides a stable bone-prosthesis interface without any aseptic loosening.

Vitamin E Phosphate Coating Stimulates Bone Deposition in Implant-related Infections in a Rat Model

BACKGROUND

Implant-related infections are associated with impaired bone healing and osseointegration. In vitro antiadhesive and antibacterial properties and in vivo antiinflammatory effects protecting against bone loss of various formulations of vitamin E have been demonstrated in animal models. However, to the best of our knowledge, no in vivo studies have demonstrated the synergistic activity of vitamin E in preventing bacterial adhesion to orthopaedic implants, thus supporting the bone-implant integration.

QUESTIONS/PURPOSES

The purpose of this study was to test whether a vitamin E phosphate coating on titanium implants may be able to reduce (1) the bacterial colonization of prosthetic implants and (2) bone resorption and osteomyelitis in a rat model of Staphylococcus aureus-induced implant-related infection.

METHODS

Twelve rats were bilaterally injected in the femurs with S aureus UAMS-1-Xen40 and implanted with uncoated or vitamin E phosphate-coated titanium Kirschner wires without local or systemic antibiotic prophylaxis. Eight rats represented the uninfected control group. A few hours after surgery, two control and three infected animals died as a result of unexpected complications. With the remaining rats, we assessed the presence of bacterial contamination with qualitative bioluminescence imaging and Gram-positive staining and with quantitative bacterial count. Bone changes in terms of resorption and osteomyelitis were quantitatively analyzed through micro-CT (bone mineral density) and semiquantitatively through histologic scoring systems.

RESULTS

Six weeks after implantation, we found only a mild decrease in bacterial count in coated versus uncoated implants (Ti versus controls: mean difference [MD], -3.705; 95% confidence interval [CI], -4.416 to -2.994; p < 0.001; TiVE versus controls: MD, -3.063; 95% CI, -3.672 to -2.454; p < 0.001), whereas micro-CT analysis showed a higher bone mineral density at the knee and femoral metaphysis in the vitamin E-treated group compared with uncoated implants (knee joint: MD, -11.88; 95% CI, -16.100 to -7.664; p < 0.001 and femoral metaphysis: MD, -19.87; 95% CI, -28.82 to -10.93; p < 0.001). We found decreased osteonecrosis (difference between medians, 1.5; 95% CI, 1-2; p < 0.002) in the infected group receiving the vitamin E-coated nails compared with the uncoated nails.

CONCLUSIONS

These preliminary findings indicate that vitamin E phosphate implant coatings can exert a protective effect on bone deposition in a highly contaminated animal model of implant-related infection.

CLINICAL RELEVANCE

The use of vitamin E coatings may open new perspectives for developing coatings that can limit septic loosening of infected implants with bacterial contamination. However, a deeper insight into the mechanism of action and the local release of vitamin E as a coating for orthopaedic implants is required to be used in clinics in the near future. Although this study cannot support the antimicrobial properties of vitamin E, promising results were obtained for bone-implant osseointegration. These preliminary results will require further in vivo investigations to optimize the host response in the presence of antibiotic prophylaxis.

Implant and limb survival after resection of primary bone tumors of the lower extremities and reconstruction with mega-prostheses fifty patients followed for a mean of forteen years

PURPOSE

Previous studies reported variable outcome and failure rates after mega-prosthetic reconstructions in the lower extremities. The purpose of this study was to make a long-term single-center evaluation of patients treated with limb-sparing surgery and reconstruction with mega-prostheses in the lower extremities.

METHODS

We identified 50 patients (osteosarcoma (n = 30), chondrosarcoma (n = 9), osteoclastoma (n = 6), Ewing sarcoma (n = 4), angiosarcoma (n = 1)), who underwent limb-sparing reconstruction of the lower extremities (proximal femur (n = 9), distal femur (n = 29), proximal tibia (n = 9), and the entire femur (n = 3)) between 1985 and 2005. Surviving patients not lost to follow-up were evaluated using the MSTS score. Causes of failure were classified according to the Henderson classification. Kaplan-Meier survival analysis was used for evaluation of patient, prosthesis, and limb survival.

RESULTS

Twenty-eight patients were alive at follow-up. Fifty-four percent had revision surgery (n = 27). The ten year patient survival was 60% (95%CI 46-74%); the ten year implant survival was 24% (95%CI 9-41%), and the ten year limb survival rate was 83% (95%CI 65-96%). Type 1 failure occurred in 9%, type 2 in 16%, type 3 in 28%, type 4 in 18%, and type 5 in 3%. Mean MSTS score was 21 (range, 6-30), representing a median score of 71%.

CONCLUSIONS

Our long-term results with mega-prostheses justify the use of limb-salvage surgery and prosthetic reconstruction. Our results are fully comparable with other findings, with regard to limb and prosthesis survival, but also with regard to functional outcome.

The use of a non-invasive extendable prosthesis at the time of revision arthroplasty

Aims

The use of a noninvasive growing endoprosthesis in the management of primary bone tumours in children is well established. However, the efficacy of such a prosthesis in those requiring a revision procedure has yet to be established. The aim of this series was to present our results using extendable prostheses for the revision of previous endoprostheses.

Patients and Methods

All patients who had a noninvasive growing endoprosthesis inserted at the time of a revision procedure were identified from our database. A total of 21 patients (seven female patients, 14 male) with a mean age of 20.4 years (10 to 41) at the time of revision were included. The indications for revision were mechanical failure, trauma or infection with a residual leg-length discrepancy. The mean follow-up was 70 months (17 to 128). The mean shortening prior to revision was 44 mm (10 to 100). Lengthening was performed in all but one patient with a mean lengthening of 51 mm (5 to 140).

Results

The mean residual leg length discrepancy at final follow-up of 15 mm (1 to 35). Two patients developed a deep periprosthetic infection, of whom one required amputation to eradicate the infection; the other required two-stage revision. Implant survival according to Henderson criteria was 86% at two years and 72% at five years. When considering revision for any cause (including revision of the growing prosthesis to a non-growing prosthesis), revision-free implant survival was 75% at two years, but reduced to 55% at five years.

Conclusion

Our experience indicates that revision surgery using a noninvasive growing endoprosthesis is a successful option for improving leg length discrepancy and should be considered in patients with significant leg-length discrepancy requiring a revision procedure. Cite this article: Bone Joint J 2018;100-B:370-7.

[Extracorporeal irradiation : Reimplantation of bone segments in the treatment of malignant bone tumours]

BACKGROUND

Malignant bone tumors themselves and the wide resection required because of them may cause huge bone defects in the bone segment involved. Autologous bone grafts are a reliable option to cover these defects in many cases but their availability is limited. Besides common alternative reconstruction methods, including the use of allografts and/or prostheses, especially extracoroporeal irradiation (ECI) and reimplantation of the bone segment involved is attracting increasingly more attention nowadays.

DISCUSSION

In the following, we report on indications/contraindications, details of the operative technique, as well as the recommended rehabilitation regime of ECI. Furthermore, we compare our own results with those published in the recent literature. Especially the advantages and disadvantages of this method, the risks and the complications are illustrated and critically discussed.

CONCLUSION

Extracorporeal irradiation of a tumor bearing bone segment is a valuable alternative reconstruction technique following tumor resections of the pelvis, femur and tibia, with encouraging results with respect to local control, complication risks and functional outcome.

Silver-Coated Megaprosthesis of the Proximal Tibia in Patients With Sarcoma

BACKGROUND

Proximal tibia arthroplasty is associated with high rates of infection. This study is the largest one that has compared the infection rates with titanium vs silver-coated megaprostheses in patients treated for sarcomas.

METHODS

The infection rate in 98 patients with sarcoma or giant-cell tumor in the proximal tibia who underwent placement of a titanium (n = 42) or silver-coated (n = 56) megaprosthesis (MUTARS) was assessed, along with the treatments administered for any infection.

RESULTS

As the primary end point of the study, the rates of infection were 16.7% in the titanium group and 8.9% in the silver group, resulting in 5-year prosthesis survival rates of 90% in the silver and 84% in the titanium group. Whereas in the titanium group 37.5% of patients ultimately had to undergo amputation in the present study, these mutilating surgical procedures were only necessary in the silver group in one patient (14.3%).

CONCLUSION

The use of silver-coated prosthesis reduced the infection rate in a relatively large and homogeneous group of patients. In addition, less-aggressive treatment of infection was possible in the group with silver-coated prosthesis.

pH dependent silver nanoparticles releasing titanium implant: A novel therapeutic approach to control peri-implant infection

Peri-implant infection control is crucial for implant fixation and durability. Antimicrobial administration approaches to control peri-implant infection are far from satisfactory. During bacterial infection, pH level around the peri-implant surface decreases as low as pH 5.5. This change of pH can be used as a switch to control antimicrobial drug release from the implant surface. Silver nanoparticles (AgNPs) have broad-spectrum antimicrobial properties. In this study, we aimed to design a pH-dependent AgNPs releasing titania nanotube arrays (TNT) implant for peri-implant infection control. The nanotube arrays were fabricated on the surface of titanium implant as containers; AgNPs were grafted on TNT implant surface via a low pH-sensitive acetal linker (TNT-AL-AgNPs). SEM, TEM, AFM, FTIR as well as XPS data showed that AgNPs have been successfully linked to TNT via acetal linker without affecting the physicochemical characteristics of TNT. The pH 5.5 enhanced AgNPs release from TNT-AL-AgNPs implant compared with pH 7.4. AgNPs released at pH 5.5 robustly increased antimicrobial activities against gram-positive and gram-negative bacteria compared with AgNPs released at pH 7.4. TNT-AL-AgNPs implant enhanced osteoblast proliferation, differentiation, and did not affect osteoblast morphology in vitro. In conclusion, incorporation of AgNPs in TNT via acetal linker maintained the surface characteristics of TNT. TNT-AL-AgNPs implant was biocompatible to osteoblasts and showed osteoinductive properties. AgNPs were released from TNT-AL-AgNPs implant in high dose at pH 5.5, and this release showed strong antimicrobial properties in vitro. Therefore, this novel design of low pH-triggered AgNPs releasing TNT-AL-AgNPs could be an infection-triggered antimicrobial releasing implant model to control peri-implant infection.

Megaprosthesis of the knee in tumor and revision surgery

The introduction of multidisciplinary approach with chemo and radiotherapy, the advances in surgical and the improvements of diagnostic techniques allowed limb salvage surgery in most cases of bone sarcomas instead of amputation. Modular megaprostheses are the most common method of reconstruction after segmental resection of the long bones in the extremities for their availability, immediate fixation, early weight bearing, good function. Despite the advances in materials and implant designs, these systems have an high incidence of complications. Aim of this study was to report the experience on mega-prostheses implanted around the knee in tumor and revision surgery to analyze: the most frequent used current systems, the problems of stems fixation, extensor mechanism reconstructions in proximal tibia resections and the preservation of growth of the lower extremity in children.

Megaprosthesis of the knee in tumor and revision surgery

The introduction of multidisciplinary approach with chemo and radiotherapy, the advances in surgical and the improvements of diagnostic techniques allowed limb salvage surgery in most cases of bone sarcomas instead of amputation. Modular megaprostheses are the most common method of reconstruction after segmental resection of the long bones in the extremities for their availability, immediate fixation, early weight bearing, good function. Despite the advances in materials and implant designs, these systems have an high incidence of complications. Aim of this study was to report the experience on mega-prostheses implanted around the knee in tumor and revision surgery to analyze: the most frequent used current systems, the problems of stems fixation, extensor mechanism reconstructions in proximal tibia resections and the preservation of growth of the lower extremity in children. (www.actabiomedica.it)