Efficacy of different revision procedures for infected megaprostheses in musculoskeletal tumour surgery of the lower limb

What Is the Diagnostic Performance and Accuracy of Serum Inflammatory Biomarkers and Synovial Fluid Analysis in Megaprosthetic Periprosthetic Joint Infections?

BACKGROUND

Serum biomarkers and synovial fluid analysis are valuable tools for the preoperative diagnosis of periprosthetic joint infections (PJIs). However, the literature on their utility in megaprostheses is limited. Our study aimed to assess the diagnostic performance and accuracy of four laboratory tests for diagnosing PJI in patients who have megaprostheses.

METHODS

We retrospectively reviewed 104 patients who underwent 126 revisions after oncologic megaprosthesis reconstruction. Revisions were stratified into aseptic and septic according to the International Consensus Meeting criteria. The PJIs were classified into acute and chronic infections based on time since index surgery. There were four tests assessed: serum C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), synovial white blood cell (WBC) count, and polymorphonuclear percentage (PMN%). Receiver operating characteristic curve analysis was conducted to assess their performance.

RESULTS

The diagnostic performance of preoperative tests in acute PJIs ranked by area under the curve was CRP (0.86), ESR (0.81), synovial WBC count (0.76), and synovial PMN% (0.69). In chronic PJIs, diagnostic performance ranked by area under the curve was synovial WBC count (0.80), CRP (0.77), ESR (0.71), and synovial PMN% (0.67). New cutoff values for diagnosing acute PJIs were identified as CRP ≥ 42 mg/L, synovial WBC count ≥ 5,500 cells/μL, and synovial PMN% ≥ 92.5%. For chronic PJIs, new cutoff values of CRP ≥ 31 mg/L, ESR ≥ 24.5 mm/hour, synovial WBC count ≥ 5,550 cells/μL, and synovial PMN% ≥ 76.5% were established. These cutoff values improved diagnostic accuracy in both acute and chronic PJIs.

CONCLUSIONS

Good to excellent diagnostic performance was seen with all tests except synovial PMN%. Adjusting cutoff values in patients who have megaprosthesis revisions improved diagnostic performance.

Successful limb-salvage procedure using a bioexpandable prosthesis after infected primary reconstruction of the distal femur in a skeletally immature patient: a case report

BACKGROUND

Periprosthetic infections pose a devastating complication in skeletally immature patients treated for an orthopaedic oncological condition. Reconstructive approaches to revision procedures are often limited, and many cases still require amputation.

CASE PRESENTATION

In this report, we present our unique experience with the bio-expandable MUTARS® BioXpand prosthesis, utilized during the second stage of a revision surgery in an adolescent female patient. Initially, the patient underwent reconstruction using a conventional endoprosthesis following the resection of a high-grade distal femur osteosarcoma; however, she developed a deep infection six months later. During a two-stage revision procedure, the infection was successfully eradicated at the cost of loss of growth potential at also the site of proximal tibia. The initial 5 cm limb-length discrepancy was restored through the application of bioexpandable endoprosthesis, which allowed for an 8 cm gain in bone stock. At the last follow-up appointment, the patient was fully weight-bearing and demonstrated excellent clinical outcomes, with no evidence of infection or tumor recurrence.

CONCLUSION

This successful limb-salvage procedure indicates that bioexpandable endoprosthesis may serve as a viable and effective reconstructive option in revision surgery for skeletally immature individuals.

Two-stage revision for infection of oncological megaprostheses : a multicentre EMSOS study

Aims

The aim of this study was to assess the incidence of reinfection in patients after two-stage revision of an infected megaprosthesis (MPR) implanted after resection of a bone tumour.

Methods

A retrospective study was carried out of 186 patients from 16 bone sarcoma centres treated between January 2010 and December 2020. The median age at the time of tumour diagnosis was 26 years (IQR 17 to 33); 69 (37.1%) patients were female, and 117 (62.9%) were male.

Results

A total of 186 patients with chronic MPR infections were included. Median follow-up was 68 months (IQR 31 to 105). The most represented sites of MPR were distal femur in 93 cases (50.0%) and proximal tibia in 53 cases (28.5%). Polymicrobial infections were seen in 34 cases (18.3%). The most frequent isolated pathogens were staphylococci. Difficult-to-treat (DTT) pathogens were isolated in 50 cases (26.9%). The estimated infection recurrence (IR) rate was 39.1% at five years and 50.0% at ten years. A higher IR rate was found in DTT PJI compared to non-DTT infections (p = 0.019). Polymicrobial infections also showed a higher rate of infection recurrence (p = 0.046).

Conclusion

This study suggests that an infected MPR treated by two-stage revision and ultimately reimplantation with a MPR can be successful, but the surgeon must be aware of a high recurrence rate compared to those seen with infected conventional implants.

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

BACKGROUND

Two-stage revision for periprosthetic joint infection (PJI) in patients who have undergone segmental replacement of the distal femur or proximal tibia after tumor resection can be associated with considerable morbidity, pain, and risk of complications because the procedure often results in removal of long, well-fixed stems from the diaphysis. A less-aggressive surgical approach, such as debridement, antibiotics, and implant retention (DAIR), may be attractive to patients and surgeons because of less morbidity, but the likelihood of eradicating infection in comparison to the traditional two-stage revision is not well established for oncology patients. Furthermore, the relative risk of subsequent amputation for DAIR versus two-stage revision has not been defined for this population.

QUESTIONS/PURPOSES

(1) How does DAIR compare with two-stage revision in terms of infection control for patients with distal femoral or proximal tibial segmental modular endoprostheses? (2) Is DAIR as an initial procedure associated with an increased risk of amputation compared with two-stage revision for infection?

METHODS

From the longitudinally maintained orthopaedic oncology surgical database at our institution, we identified 69 patients who had been treated for a clinical diagnosis of PJI at the knee between 1993 and 2015. We excluded 32% (22) of patients who did not meet at least one of the major criteria of the Musculoskeletal Infection Society (MSIS) for PJI, 3% (2) of patients who underwent immediate amputation, 3% (2) of patients who had a follow-up time of < 24 months, and 7% (5) of patients who did not have a primary tumor of the distal femur or proximal tibia. The study consisted of 38 patients, of whom eight underwent two-stage revision, 26 underwent DAIR, and four underwent extended DAIR (removal of all segmental components but with retention of stems and components fixed in bone) for their initial surgical procedure. To be considered free of infection, patients had to meet MSIS standards, including no positive cultures, drainage, or surgical debridement for a minimum of 2 years from the last operation. Factors associated with time-dependent risk of infection relapse, clearance, amputation, and patient survival were analyzed using Kaplan-Meier survivorship curves and the log-rank test to compare factors. Association of demographic and treatment factors was assessed using chi-square and Fisher exact tests.

RESULTS

Continuous infection-free survival at 5 years was 16% (95% CI 2% to 29%) for patients undergoing DAIR compared with 75% (95% CI 45% to 100%) for patients undergoing two-stage revision (p = 0.006). The median (range) number of total surgical procedures was 3 per patient (1 to 10) for DAIR and 2 (2 to 5) for two-stage revision. Twenty-nine percent (11 of 38) of patients eventually underwent amputation. Survival without amputation was 69% (95% CI 51% to 86%) for DAIR compared with 88% (95% CI 65% to 100%) for two-stage revision at 5 years (p = 0.34). The cumulative proportion of patients achieving infection-free status (> 2 years continuously after last treatment) and limb preservation was 58% (95% CI 36% to 80%) for patients initially treated with DAIR versus 87% (95% CI 65% to 100%) for patients first treated with two-stage revision (p = 0.001).

CONCLUSION

Infection control was better with two-stage revision than DAIR. The chance of eventual clearance of infection with limb preservation was better when two-stage revision was chosen as the initial treatment. However, the loss to follow-up in the two-stage revision group would likely make the true proportion of infection control lower than our estimate. Our experience would suggest that the process of infection eradication is a complex and difficult one. Most patients undergo multiple operations. Nearly one-third of patients eventually underwent amputation, and this was a serious risk for both groups. While we cannot strongly recommend one approach over the other based on our data, we would still consider the use of DAIR in patients who present with acute short duration of symptoms (< 3 weeks), no radiographic signs of erosion around fixed implants, and organisms other than Staphylococcus aureus . We would advocate the extended DAIR procedure with removal of all segmental or modular components, and we would caution patients that there is a high likelihood of needing further surgery. A prospective trial with strict adherence to indications may be needed to evaluate the relative merits of an extended DAIR procedure versus a two-stage revision.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Periprosthetic Joint Infection Surrounding Lower-Extremity Endoprostheses After Tumor Resection: Causative Microorganisms, Effectiveness of DAIR, and Risk Factors for Treatment Failure

Background

Periprosthetic joint infection (PJI) surrounding an endoprosthesis after reconstruction of a lower extremity following tumor resection is a common complication, and the treatment of these infections is challenging and often requires multiple surgical interventions or even implant removal. Because there has been limited evidence to support treatment strategies and understanding of the epidemiology of the causative microorganisms, we analyzed the effectiveness of debridement, antibiotics, and implant retention (DAIR), risk factors for the failure of DAIR, and causative microorganisms in patients with a PJI surrounding a lower-extremity endoprosthesis after tumor resection.

Methods

A retrospective cohort study was conducted in a tertiary referral center for orthopaedic oncology. All patients treated between 2000 and 2018 for PJI surrounding a lower-extremity endoprosthesis after tumor resection were included. Treatment outcomes and risk factors for failure were analyzed in patients primarily treated with DAIR. Causative microorganisms were recorded. The minimum follow-up period was 2 years.

Results

Of the 337 patients who underwent endoprosthetic reconstruction of a lower extremity after tumor resection, 67 patients (20%) developed a PJI surrounding the endoprosthesis. Of those patients, 55 were primarily treated with DAIR. The functional cure rate of DAIR was 65% (36 of 55). A median of 2 debridements per patient was needed. Chemotherapy (odds ratio [OR], 3.1 [95% confidence interval (CI), 1.0 to 9.3]) and an erythrocyte sedimentation rate of >50 mm/hr at diagnosis (OR, 4.5 [95% CI, 1.3 to 15.4]) were associated with treatment failure. Nineteen patients (28%) had a polymicrobial infection.

Conclusions

Although sequential procedures are often needed, DAIR has acceptable clinical outcomes and should be considered, dependent on expected survival and the risk factors for treatment failure noted in this study.

Level of Evidence

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

Managing Wound Complications After Osteosarcoma Resection: Stopping Adjuvant Therapy and Performing Secondary Closure

Purpose Adjuvant chemotherapy (AC) following limb-sparing surgery with endoprosthesis is the gold standard treatment for osteosarcoma (OS). However, AC can impair wound healing, leading to endoprosthesis exposure, making the decision to continue or pause AC important. We propose standard guidelines for managing this situation. Methods  This observational retrospective study analyzed local findings, AC courses, wound complications, and overall survival of 22 patients who underwent resection of primary OS. Results Of nine patients with wound complications (41%), two achieved secondary healing before starting AC while the other seven patients had wound deterioration during AC. Six patients had temporary suspension of AC, followed by debridement and secondary closure, and the completion of AC, one had temporary suspension of AC with conservative therapy, but could not complete AC due to too long suspension of AC. No recurrence or metastasis was recorded. Comparing these nine patients with the other 13 patients without wound complications, the number of days from the operation to the end of AC was 150 days and 144 days respectively, and no statistical differences were observed (p=0.648). Conclusion Managing wound complications after OS resection requires balancing the completion of AC with effective limb salvage strategies. Deciding on temporary suspension of AC without delay and secondary closure is important.

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.

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.

Characteristics and Epidemiology of Megaprostheses Infections: A Systematic Review

BACKGROUND

Megaprostheses were first employed in oncological orthopedic surgery, but more recently, additional applications have arisen. These implants are not without any risks and device failure is quite frequent. The most feared complication is undoubtedly the implants' infection; however, the exact incidence is still unknown. This systematic review aims to estimate in the current literature the overall incidence of megaprosthesis infections and to investigate possible risk/protective factors.

METHODS

We conducted a systematic search for studies published from July 1971 to December 2023 using specific keywords. To be included, studies needed to report either the megaprosthesis anatomical site, and/or whether the megaprosthesis was coated, and/or the surgical indication as oncological or non-oncological reasons.

RESULTS

The initial literature search resulted in 1281 studies. We evaluated 10,456 patients and the overall infection rate was 12%. In cancer patients, the infection rate was 22%, while in non-oncological patients, this was 16% (trauma 12%, mechanical failure 17%, prosthetic joint infections 26%). The overall infection rates comparing coated and uncoated implants were 10% and 12.5%, respectively.

CONCLUSIONS

The number of megaprosthesis implants is increasing considerably. In traumatological patients, the infection rate is lower compared to all the other subgroups, while the infection rate remains higher in the cancer patient group. As these devices become more common, focused studies exploring epidemiological data, clinical outcomes, and long-term complications are needed to address the uncertainties in prevention and management.

Controversies in orthopaedic oncology

Chondrosarcoma is the second most common surgically treated primary bone sarcoma. Despite a large number of scientific papers in the literature, there is still significant controversy about diagnostics, treatment of the primary tumour, subtypes, and complications. Therefore, consensus on its day-to-day treatment decisions is needed. In January 2024, the Birmingham Orthopaedic Oncology Meeting (BOOM) attempted to gain global consensus from 300 delegates from over 50 countries. The meeting focused on these critical areas and aimed to generate consensus statements based on evidence amalgamation and expert opinion from diverse geographical regions. In parallel, periprosthetic joint infection (PJI) in oncological reconstructions poses unique challenges due to factors such as adjuvant treatments, large exposures, and the complexity of surgery. The meeting debated two-stage revisions, antibiotic prophylaxis, managing acute PJI in patients undergoing chemotherapy, and defining the best strategies for wound management and allograft reconstruction. The objectives of the meeting extended beyond resolving immediate controversies. It sought to foster global collaboration among specialists attending the meeting, and to encourage future research projects to address unsolved dilemmas. By highlighting areas of disagreement and promoting collaborative research endeavours, this initiative aims to enhance treatment standards and potentially improve outcomes for patients globally. This paper sets out some of the controversies and questions that were debated in the meeting.

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.

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.

The microbial profile of infected endoprosthetic reconstructions after wide excision for patients with musculoskeletal tumors: A call for pathogen-based practices

BACKGROUND AND OBJECTIVES

Periprosthetic infection is a devastating complication following endoprosthetic reconstruction. This study utilized a large database of endoprostheses to describe the incidence, risk factors, and microbial profile of such infections to better catalogue and understand these catastrophic events.

METHODS

A retrospective review of endoprosthetic reconstructions for an oncologic indication from January 1, 1981 to December 31, 2020 was performed. Demographic, oncologic, procedural and outcome data was analyzed. Multivariable logistic regression was used to identify potential risk factors for infection with significance defined as p < 0.05.

RESULTS

Forty four out of 712 (6.2%) reconstructions resulted in infection at a mean time of 39.9 ± 44.5 months. Revision surgery (odds ratio [OR] 6.14, p < 0.001) or having a postoperative wound complication (OR 7.67, p < 0.001) were significantly associated with infection. Staphylococcus aureus and Staphylococcus epidermidis were the most commonly cultured organisms at a rate of 34.1% (15/44) and 22.7% (10/44), respectively. Ten infections resulted in amputation; five due to antimicrobial-resistant infections and three due to polymicrobial infections.

CONCLUSION

Understanding the microbial profile of patients undergoing endoprosthetic reconstruction is paramount. This study demonstrates a relatively high rate of polymicrobial and antibiotic-resistant infections that portend worse outcomes, thus suggesting that pathogen-specific infectious practices may be warranted.

LEVEL OF EVIDENCE

Retrospective cohort study, level III.

Osseointegration reduces aseptic loosening of primary distal femoral implants in pediatric and adolescent osteosarcoma patients: a retrospective clinical and radiographic study

AIM

The challenge of distal femoral replacement (DFR) longevity remains a priority for orthopaedic oncologists as the overall survival and activity level of young patients with osteosarcoma continues to improve. This study hypothesized that increased extracortical osseointegration at the bone-implant shoulder (i.e., where the metal implant shaft abuts the femur) will improve stress transfer adjacent to the implant, as evidenced by reduced cortical bone loss, radiolucent line progression and implant failure in young patients (< 20 years) following DFR surgery.

METHODS

Twenty-nine patients of mean age 13.09 ± 0.56 years received a primary DFR. The clinical outcome of 11 CPS®, 10 GMRS®, 5 Stanmore® and 3 Repiphysis® implants was evaluated over a mean follow-up period of 4.25 ± 0.55 years. The osseous response to a bone-implant shoulder composed of either a hydroxyapatite-coated grooved ingrowth collar (Stanmore®), a porous metal coating (GMRS®) or a polished metal surface (Repiphysis®) was quantified radiographically.

RESULTS

All (100.0%) of the Stanmore® implants, 90.0% of GMRS®, 81.8% of CPS® and 33.3% of the Repiphysis® implants survived. Significantly increased extracortical bone and osseointegration were measured adjacent to the Stanmore® bone-implant shoulder when compared with the GMRS® and Repiphysis® implants (p < 0.0001 in both cases). Significantly decreased cortical loss was identified in the Stanmore® group (p = 0.005, GMRS® and p < 0.0001, Repiphysis®) and at 3 years, the progression of radiolucent lines adjacent to the intramedullarly stem was reduced when compared with the GMRS® and Repiphysis® implants (p = 0.012 and 0.026, respectively).

CONCLUSIONS

Implants designed to augment osseointegration at the bone-implant shoulder may be critical in reducing short- (≤ 2 years) to mid- (≤ 5 years) term aseptic loosening in this vulnerable DFR patient group. Further longer-term studies are required to confirm these preliminary findings.

Using 3D Printing Technology to Manufacture Personalized Bone Cement Placeholder Mold for Bone Defect Repair and Reconstruction with Infection: A Case Report

BACKGROUND

Limb salvage surgery is the preferred treatment for most malignant bone tumors, but postoperative infection treatment is very challenging. Simultaneously controlling infection and solving bone defects are clinical treatment challenges.

CASE PRESENTATION

Here we describe a new technique for treating bone defect infection after bone tumor surgery. An 8-year-old patient suffered an incision infection after osteosarcoma resection and bone defect reconstruction. In response, we designed her a personalized, anatomically matched, antibiotic-loaded, bone cement spacer mold using 3D printing technology. The patient's infection was cured, and limb salvage was successful. In follow-up, the patient had returned to normal postoperative chemotherapy and was able to walk with the help of a cane. There was no obvious pain in the knee joint. At 3 months after operation, the range of motion of the knee joint was 0°-60°.

CONCLUSION

The 3D printing spacer mold is an effective solution for treating the infection with large bone defect.

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.

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.

Single-Stage Revision of Infected Total Femoral Replacement

We present 2 cases of infected total femur prosthetic devices treated with a single-stage revision with extensive irrigation and debridement, followed by reimplantation with a prosthesis coated in antibiotic-impregnated cement. Single-stage total femoral replacement with antibiotic-eluting cement around the device was used for 2 cases of limb salvage arthroplasty to reduce complications, maintain patient function, and minimize hospital-associated cost. [Orthopedics. 2022;45(5):e280-e283.].

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

BACKGROUND

Tumor resection and prosthetic replacement have become the treatments of choice for malignant bone tumors. Infections are the leading cause of failure of limb salvage surgeries. Therefore, treating infections around prostheses after limb salvage is essential and challenging. Our research team designed a "domino" sequential treatment plan to treat postoperative infections around tumor prostheses and evaluated its efficacy.

PURPOSE

To introduce the new domino sequential treatment plan for postoperative infections of tumor prostheses, and evaluate the technical points of the plan and prognosis in medium- and long-term follow-ups.

METHODS

Between January 2015 and August 2021, 14 patients were treated with prosthesis-preserving domino sequential therapy for peripheral prosthesis infections after bone-tumor limb salvage. The sample included eight cases of distal femur tumor, two of proximal tibia tumor, three of pelvic tumor, and one of middle femur tumor. We evaluated routine blood test results, C-reactive protein level, the erythrocyte sedimentation rate, and other indicators. X-rays and CT scans of the surgical site were obtained and the Musculoskeletal Tumor Society (MSTS) score was calculated. Treatment involved debridement and lavage of the prosthesis, and systemic and local antibiotics.

RESULTS

The positivity rate of microbial culture was 78.6%. There were three cases of Staphylococcus aureus, one of Staphylococcus epidermidis, two of methicillin-resistant Staphylococcus epidermidis, one of methicillin-resistant Staphylococcus aureus, two of Acinetobacter baumannii, one of Streptococcus lactis (group C), one of Streptococcus mitis, and three with negative cultures. In three cases, sequential treatment failed to control the infection. The operation success rate was 78.6% (11/14). One case eventually required amputation, and another required long-term wound dressings. To control the infection, a third had to be treated using antibiotic bone cement combined with the "intramedullary nail reverse double insertion" technique. The MSTS scores of patients before infection debridement and at the last follow-up showed statistically significant differences (t = 5.312, p = 0.02).

CONCLUSIONS

The prosthesis-preserving domino sequential method has certain advantages for treating bone-tumor limb salvage infections around the prosthesis.

LEVEL OF EVIDENCE

Level IV, therapeutic.

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.

Is the Capanna Technique a Reliable Method for Revision Surgery after Failure of Previous Limb-Salvage Surgery?

BACKGROUND

Reconstruction of a massive bone defect caused by previous failed limb-salvage surgery in patients with bone sarcoma is challenging. Many procedures have been used, but they all have their inherent disadvantages. The Capanna technique has demonstrated good functional outcomes and a low incidence of complications in primary reconstructive surgery of massive bone defect. However, few studies have focused on its usage in revision surgery after failed primary limb-salvage surgery.

METHODS

Between June 2011 and January 2017, 13 patients underwent revision surgery with the Capanna technique for reconstruction of a secondary segmental bone defect caused by a previous failed surgical procedure. The demographics, operating procedures, graft union, functional outcomes, oncologic outcomes, and postoperative complications of each patient were recorded.

RESULTS

The current study investigated 13 patients. The rate of limb salvage was 100 %. Bone union was achieved for all patients during a mean time of 8.54 ± 2.15 months (range 4-11 months) at the fibula-host bone junction and 14.92 ± 2.33 months (range 12-21 months) at the allograft-host bone junction. The postoperative complications included wound healing issues and internal fixation loosening. Allograft fracture, nonunion, and infection were not observed. All the patients achieved good functional outcomes, with a Musculoskeletal Tumor Society (MSTS) score of 0.86 ± 0.03 at the latest follow-up visit.

CONCLUSIONS

The Capanna technique is a reliable alternative method for revision reconstruction of a segmental bone defect caused by a previous failed surgical procedure.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

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.

Compressive osseointegration for endoprosthetic reconstruction

This review summarizes the biomechanical concepts, clinical outcomes and limitations of compressive osseointegration fixation for endoprosthetic reconstruction. Compressive osseointe - gration establishes stable fixation and integration through a novel mechanism; a Belleville washer system within the spindle applies 400-800 PSI force at the boneimplant interface. Compressive osseointegration can be used whenever standard endoprosthetic reconstruction is indicated. However, its mode of fixation allows for a shorter spindle that is less limited by the length of remaining cortical bone. Most often compressive osseointegration is used in the distal femur, proximal femur, proximal tibia, and humerus but these devices have been customized for use in less traditional locations. Aseptic mechanical failure occurs earlier than with standard endoprosthetic reconstruction, most often within the first two years. Compressive osseointegration has repeatedly been proven to be non-inferior to standard endoprosthetic reconstruction in terms of aseptic mechanical failure. No demographic, device specific, oncologic variables have been found to be associated with increased risk of aseptic mechanical failure. While multiple radiographic parameters are used to assess for aseptic mechanical failure, no suitable method of evaluation exists. The underlying pathology associated with aseptic mechanical failure demonstrates avascular bone necrosis. This is in comparison to the bone hypertrophy and ingrowth at the boneprosthetic interface that seals the endosteal canal, preventing aseptic loosening.

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.

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

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

Fighting Megaprosthetic Infections: What are the Chances of Winning?

BACKGROUND

Megaprosthetic infections continue to be a leading mode of failure after limb salvage surgery. Though challenging, amputations can be avoided with proper management in majority of the cases. This study aims to describe the spectrum of mega-endoprosthetic infections at our institute and assess the treatment efficacy in these patients.

MATERIALS AND METHODS

All patients treated for endoprosthetic infection at our institute between 2010 and 2018 were retrospectively analyzed for overall survival of reconstruction method, site and type of megaprosthesis, adjuvant therapy, microbial isolates, surgical and medical management and outcomes.

RESULTS

Thirty-five patients (22 males: 13 females) were analyzed following treatment for endoprosthetic infection. Majority were around the knee joint [most commonly with proximal tibia (n = 14) followed by distal femur (n = 12) megaprosthesis]. Ten patients had undergone primary surgical procedure at our institute, while 25 patients presented with infection after megaprosthesis implantation. In the 28 culture-positive infections, the most common micro-organism was Staphylococcus spp. (18 patients: methicillin-sensitive Staphylococcus aureus = 9, coagulase-negative Staphylococcus = 5, methicillin-resistant Staphylococcus aureus = 1, Staphylococcus epidermidis = 3) and poly-microbial infection was present in three patients. Nine patients underwent successful debridement and wound wash with insertion of antibiotic impregnated cement beads in 5/9 cases. Twenty-one patients required a two-stage revision. Of these 30 patients, all but one has completely resolved infections. One patient with resurfaced late infection after re-implantation is on chronic suppressive antimicrobial therapy and close follow-up. Amputation because of uncontrolled infection was performed in three patients (one death post-operatively due to systemic complications of septicemia), while two patients opted for amputation as opposed to stage revisions. Median antimicrobial therapy duration was 6 weeks (1-12 weeks). Reconstructive surgery for soft tissue cover was required in seven patients.

CONCLUSIONS

In patients with early or acute presentation without frank granulation or pus around the implant, debridement and insertion of antibiotic cement beads was adequate. Two-stage revisions with complete removal of the megaprosthesis showed best results in infections that could be controlled with antimicrobial therapy. More than one exchange of cement spacer was required for uncontrolled infections. Multidisciplinary approach in consultation with the infectious disease team is essential to determine choice of antibiotic cement for beads/spacer as well as appropriate adjuvant antimicrobial therapy to solve the challenging problem of endoprosthetic infections following bone tumor surgery. Adequate and healthy soft tissue cover of the implant should be achieved wherever indicated.

[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.

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.