Distal Femoral Replacement and Periprosthetic Joint Infection After Non-Oncological Reconstruction: A Retrospective Analysis

A UK multicentre cohort study of clinical outcomes of distal femoral replacement for nononcological conditions : the EndoProsthetic Replacement for nonOncological conditions (EPRO) study

Aims

This study aims to determine the outcomes of distal femoral replacements (DFRs) for nononcological conditions.

Methods

This was a multicentre retrospective cohort study across five UK centres between 1 August 2009 and 1 April 2023. The primary outcome was the local complication rate. Secondary outcomes assessed were blood transfusion rate, critical care requirements, return to baseline mobility and residence status, systemic complication rates, reoperation rate, and mortality rates. Implant survival analysis was performed using Kaplan-Meier methodology with local complication as the endpoint. Binary logistical regression was performed to identify risk factors for developing local complications. The study included 227 DFRs with a median age of 78.2 years (IQR 70.1 to 84.0). Indications were periprosthetic femoral fracture (PFF) (n = 74; 33%), aseptic revision arthroplasty (n = 45; 20%), acute trauma (n = 42; 19%), infected revision arthroplasty (n = 40; 18%), chronic/failed trauma (n = 14; 6%), and complex primary arthroplasty (n = 12; 5%). Median follow-up was 3.9 years (IQR 1.5 to 7.1).

Results

The local complication rate was 21% (48 cases). The most common local complications were periprosthetic joint infection (n = 22; 10%), PFF (n = 7; 3%), and aseptic loosening (n = 7; 3%). Blood transfusion was required in 57 patients (25%), while 67 (30%) required critical care facilities. A return to baseline mobility and residence was observed in 94 (50%) and 183 (83%) patients, respectively. The six-month systemic complication rate was 12% (n = 27) and the reoperation rate was 16% (n = 36). The 30-day and one-year mortality rates were 3% (n = 6) and 9% (n = 21), respectively. The two-year implant survival rate was 80.9% (SE 2.8). Binary logistic regression demonstrated surgery for infected revision arthroplasty, an increasing construct:stem ratio, and increasing operating time were associated with a higher risk of failure (p < 0.05).

Conclusion

This is the largest study of DFR for nononcological conditions. Due to high local complication and reoperation rates, it should be considered as a salvage option for complex knee reconstruction and patients should be counselled appropriately.

Comparison of Survivorship of Distal Femoral Replacements by Fixation Method

BACKGROUND

Distal femoral replacements (DFRs) are utilized in primary and revision TKA in the setting of segmental femoral bone loss, but they are known to have high failure rates. This study aimed to examine DFR survival by fixation method to determine if the use of cemented fixation or a femoral cone may decrease the risk of aseptic loosening and all-cause revision.

METHODS

This study was a retrospective, single-institution cohort study of patients who underwent DFR for revision TKA or native distal femoral fracture. Patient demographic and surgical data were collected via chart review, and the fixation method was determined using operative notes and radiographs. Patients were divided into cohorts by DFR fixation method: cemented, cementless, and cemented with a femoral cone. Outcomes of interest included revision rates, revision causes, and DFR survival by fixation method. We identified 243 DFRs for study inclusion: 187 cemented, 30 cementless, and 26 cemented with femoral cone. No significant differences were seen among groups for indication of primary DFR (P = 0.54).

RESULTS

By the last follow-up, 55 (29.4%) cemented, 4 (13.3%) cementless, and 6 (23.1%) cemented with femoral cone DFRs had required revision (P = 0.16). Causes of revision, including aseptic loosening, periprosthetic joint infection, periprosthetic fracture, and soft-tissue failure, were not significantly different among groups (P = 0.97). Femoral loosening was the primary cause of revision in eight (14.5%) cemented, one (25.0%) uncemented, and one (16.7%) cemented with femoral cone revised DFRs (P = 0.62). The five-year survival rates for cemented, uncemented, and cemented with femoral cone were 72, 87, and 77%, respectively.

CONCLUSIONS

In our retrospective cohort, the method of DFR fixation did not significantly affect rates or causes of revision. This study represents a larger sample of DFRs than comparable analyses.

Revision Distal Femoral Replacements Have More Than a 40% Failure and Reoperation Rate

INTRODUCTION

Distal femoral replacement (DFR) is a complex reconstruction option for patients who have substantial bone loss, often following multiple failed revision total knee arthroplasties (TKAs). However, five-year survivorship after DFR is only 70 to 85%, and there is a paucity of literature evaluating outcomes following revision DFRs (rDFRs). Therefore, this study aimed to analyze the survivorship and outcomes of rDFR.

METHODS

This retrospective study identified a consecutive cohort of all patients who underwent DFR at a single institution between 2004 and 2022. Among this population, patients who failed DFR and underwent rDFR were analyzed. All subjects had a minimum two-year follow-up from rDFR. There were 54 patients who underwent rDFR at a mean time of 19.7 months after their index DFR. The primary outcome was reoperation after rDFR. Secondary outcomes included the mechanism of failure, complications, readmission, amputation, and mortality.

RESULTS

Among the 54 patients who underwent rDFR, 22 patients (41%) failed rDFR and had a reoperation. At the most recent follow-up, patients who had rDFRs had a 46% 90-day readmission rate, 9% amputation rate, and 11% mortality rate. The 5-year reoperation-free survivorship after rDFR was 61%. Periprosthetic joint infection (PJI) was the most common indication for rDFR (43%) and the most common reason for failure of rDFR (59%). Women were significantly associated with the failure of rDFR (P = 0.029).

CONCLUSION

The outcomes following rDFR are poor, with high reoperation rates, early postoperative failure, complications, and amputation. These outcomes and risks should be shared with patients when discussing limb salvage options before these operations.

Prior Femoral Canal Instrumentation is a Major Risk Factor for Fixation Failure after Distal Femoral Replacement

INTRODUCTION

Distal femoral replacement (DFR) is a salvage option for massive femoral bone loss and is often performed in revision total knee arthroplasty (rTKA) that have undergone multiple prior procedures. This study aimed to report on a large cohort of DFRs performed at a tertiary referral institution regarding survivorship and risk factors for aseptic loosening, specifically the impact of a previously instrumented femoral canal.

METHODS

Between 2016 and 2021, 105 patients undergoing rTKA to DFR with a minimum two-year follow-up were identified. Kaplan-Meier estimates assessed survivorship free from all-cause reoperation, all-cause revision, and revision for aseptic loosening. Logistic regression was conducted to assess potential risk factors for radiographic loosening and the need for revision.

RESULTS

Prior femoral canal instrumentation was identified in 59% of cases, and 54% had undergone multiple prior procedures. The two-year survivorship free from revision for aseptic loosening was 93%. The two-year survivorship free from all-cause reoperation was 87% for native canals and 59% for previously instrumented canals (P = 0.008). The two-year survivorship free from all-cause revision was 100 and 81%, respectively (P = 0.014). Regression analysis found re-rTKA (Odds Ratio [OR] = 18.3, P = 0.006), prior femoral canal instrumentation (OR = 14.6, P = 0.01), and prior femoral canal cementation (OR = 8.2, P = 0.007) to be risk factors for aseptic loosening.

CONCLUSIONS

A DFR for rTKA had high two-year survivorship free from revision for aseptic loosening (93%). Regression analysis revealed multiple risk factors for aseptic femoral component loosening with a previously instrumented femoral canal, resulting in a 2.8-times higher rate of reoperation, a 10.5-times higher rate of all-cause revision, and an 11-times higher rate of aseptic loosening. Future research on fixation strategies in sclerotic, previously instrumented femoral canals should be prioritized to reduce the risk of fixation failure in this high-risk cohort.

Characterizing the Rotational Profile of the Distal Femur: A Roadmap for Distal Femoral Replacement Surgery

INTRODUCTION

Standard references for determining rotational alignment are often unavailable when performing distal femoral replacement (DFR) surgery. This study aimed to describe the rotational profile of the distal femoral osteology at common resection levels.

METHODS

Adults with CT scans of the bilateral legs were included. Exclusion criteria included fractures, congenital deformity, prior arthroplasty, or inadequate imaging. Referencing the transepicondylar axis, angles were measured in the axial plane using the following reference lines: anterior condylar axis or anterior femoral cortex axis (AFCA), posterior condylar axis or posterior femoral cortex axis (PFCA), lateral projection of the linea aspera (LAA), and Whiteside line (WL). These rotational measurements were assessed at 3, 5, 7, and 9 cm proximal of the joint line. External and internal rotation were denoted as positive and negative, respectively.

RESULTS

Fifty-one patients (102 femora) were included (mean age: 62.6 ± 13.4 years; mean body mass index: 26.0 ± 6.7 kg/m 2 ). Proximally, the anterior condylar axis/anterior femoral cortex axis became increasingly internally rotated (3-cm: -13.1 ± 3.5°, 9-cm: -21.2 ± 6.6°), whereas the posterior condylar axis/PFCA became increasingly externally rotated (3-cm: -6.7 ± 2.3°, 9-cm: 9.6 ± 6.1°). WL remained nearly perpendicular (3-cm: 88.8 ± 2.3°, 5-cm: 89.8 ± 3.7°) but was not reliably measured beyond 5 cm. The LAA was measurable proximal to 5 cm from the joint line and was internally rotated (5-cm: -58.5 ± 14.3°, 9-cm: -45.6 ± 13.4°).

CONCLUSION

Distally, WL is a reliable anatomic landmark for femoral implant rotation. At more proximal resection levels, the posterior cortex may be a valuable landmark as referencing the linea aspera may lead to gross internal rotation of the femoral implant.

Fix or Replace? Comparable Outcomes With Internal Fixation and Distal Femoral Replacement for Periprosthetic Fractures Above Total Knee Arthroplasty

BACKGROUND

The optimal treatment for periprosthetic fracture (PPfx) around total knee arthroplasty (TKA) remains a topic of debate. Due to its low incidence, comparative studies analyzing arthroplasty and fixation are lacking in the literature. The purpose of this study was to compare the outcomes of distal femoral replacement (DFR) and open reduction and internal fixation open reduction internal fixation (ORIF) for distal femur PPfx.

METHODS

We reviewed a consecutive series of 99 patients who underwent DFR (n = 54) or ORIF (n = 45) for distal femur PPfx. The indications for DFR were reviewed. Fractures were classified based on their relation to the implant using the Su classification. The primary outcome was rerevision, while secondary endpoints included inpatient complications, mortality within the first year, and mechanical complications such as loosening and non-union.

RESULTS

Type 2 fractures were the most prevalent type in both groups (DFR 37 versus ORIF 48.9%), while Type 1 fractures were more commonly treated with ORIF (35.6 versus 16.7%) and Type 3 with DFR (46.3 versus 15.6%) (P = 0.003). The preferred techniques in the ORIF group were plate osteosynthesis (66.7%) and retrograde nailing (31.1%). At a mean follow-up of 4.2 years (range, one to 14.1), DFR and ORIF did not demonstrate any difference in revision rates (13 versus 24.4%, P = 0.140) or mortality (3.7 versus 4.4%, P = 0.887). However, more mechanical complications were noted in the ORIF group (22.2 versus 7.4%, P = 0.035).

CONCLUSIONS

Both DFR and open reduction and internal fixation have comparable revision rates, complications, and clinical outcomes when used in supracondylar periprosthetic distal femur fractures. Longer-term studies are needed to assess DFR survivorship as well as outcomes of newer trauma techniques such as nail-plate combinations.

Distal Femoral Replacement for Revision Total Knee Arthroplasty in Non-Oncologic Indications: A Single-Institution Outcomes Study

INTRODUCTION

Distal femoral replacement (DFR) is a salvage procedure to manage massive bone loss in total knee arthroplasty (TKA). Few studies report mid-term (five to 10 years) to long-term (>10 years) outcomes of DFR for non-oncologic indications. The purpose of this study was to report the implant survival of DFRs in non-oncologic TKA for the entire cohort and by indication, as well as patient-reported clinical outcomes.

METHODS

We retrospectively identified all DFR performed for non-oncologic indications from 2002 to 2021 at our institution. There were three patients who had less than a 2-year follow-up who were excluded (no revisions after DFR). There were 45 DFR included who had a mean follow-up of 6.6 years (range, 2.0 to 17.2). The mean age was 75 years (range, 53 to 94), the mean body mass index was 29.2 (range, 19.2 to 52.4), and 64.4% were women. Indications for index DFR were mechanical TKA failure (40.0%), periprosthetic fracture (33.3%), and periprosthetic joint infection (26.7%). There were fourteen (31.1%) patients who underwent revision after index DFR. Reasons for the first revision were infection (seven), fracture (three), hinge dislocation (two), loosening (one), and extensor mechanism rupture (one). All DFRs were rotating hinge designs with fully cemented stems. Kaplan-Meier analysis was used to determine all-cause revision-free Survival and patient-reported outcomes were collected.

RESULTS

The revision-free survival for the entire cohort was 74.6% at five years and 60.2% at 10 years. By indication for index DFR, six of the 12 infection patients, five of the 18 mechanical failure patients, and three of the 15 fracture patients underwent revision. Differences in revision-free survival by indication were not statistically different (P = 0.221). At the final follow-up, the mean Oxford knee score was 25 (range 5 to 40), with 69% patient satisfaction.

CONCLUSION

A DFR for non-oncological indications is associated with high revision rates. Mid-term (five to 10 years) and long-term (10 years) revision-free survival is poor, and patient satisfaction is modest. Differences in survival by indication for DFR were not statistically significant. DFR remains a valuable salvage procedure, but patients need to be counseled on the expected outcome.

Prolonged prophylactic antibiotic use following megaprosthesis surgery may reduce periprosthetic infection

Introduction

Megaprostheses provide a reconstructive option for patients with bone loss after musculoskeletal tumor resection. However, the postoperative surgical site infection (SSI) risk is significant. This study aims to evaluate outcomes of extended postoperative antibiotic regimens in patients after megaprosthesis surgery and gather insight into strategies to minimize SSI.

Methods

This retrospective cohort study evaluated patients who underwent megaprosthesis surgery by a single surgeon at a single center from 2014 to 2022. Patient demographics, comorbidities, cancer treatment details, and antibiotic regimens were collected. Excluded were patients with less than 1 year of follow-up, active infection at time of surgery, non-healing wounds unrelated to SSI, and preoperative antibiotic regimens secondary to being immunocompromised. Measures of interest included the development of SSI within 1 year of surgery and development of antibiotic-related complications.

Results

Included were 49 patients, with a mean age of 61.2 ± 2.0 years and a mean BMI of 29.4 ± 7.0. The mean drain duration was 6.5 days (standard deviation [SD], 6.9 days), and the mean intravenous antibiotic administration duration was 6.4 days (SD, 6.9 days). The median time to drain removal was five days, and the median time for intravenous antibiotic cessation was five days. The mean total antibiotic administration duration (intravenous and oral) was 25.4 days (SD, 13.4 days). Only 1 patient in the included cohort (2.04 %) developed an SSI requiring operative intervention. No other patient within the cohort experienced an antibiotic-related complication.

Discussion

This study suggests that the site's current protocol for managing post-megaprosthesis antibiotic prophylaxis based on drain duration and incision healing status has resulted in a low rate of SSI and antibiotic-related complications. Further research is needed to validate these findings and gain additional insights into managing antibiotic prophylaxis after megaprosthesis surgery.

Dual Plating for Periprosthetic Distal Femoral Fractures Using the Extensile Medial or Lateral Parapatellar Approach

Periprosthetic distal femoral fractures (PDFFs) are increasing in incidence, typically affecting frail elderly patients who have complex needs. Although the use of distal femoral endoprostheses in the management of these fractures is increasing exponentially, concerns about their longevity and mechanical failures in younger patients should limit their use to older patients with limited life expectancies. In this study, we report the surgical technique for dual plating PDFFs using an extensile medial or lateral parapatellar approach and illustrate this technique with case examples. We describe the results of a case series of 15 patients who underwent dual plating for acute PDFF from 2015 to 2021 (87% female, median age 78 years; interquartile range 73-88) at a median follow-up duration of 2.4 years (interquartile range 2.0-4.2).

Double plating is a suitable option for periprosthetic distal femur fracture compared to single plate fixation and distal femoral arthroplasty

Aims

The purpose of this study was to compare reoperation and revision rates of double plating (DP), single plating using a lateral locking plate (SP), or distal femoral arthroplasty (DFA) for the treatment of periprosthetic distal femur fractures (PDFFs).

Methods

All patients with PDFF primarily treated with DP, SP, or DFA between 2008 and 2022 at a university teaching hospital were included in this retrospective cohort study. The primary outcome was revision surgery for failure following DP, SP, or DFA. Secondary outcome measures included any reoperation, length of hospital stay, and mortality. All basic demographic and relevant implant and injury details were collected. Radiological analysis included fracture classification and evaluation of metaphyseal and medial comminution.

Results

A total of 111 PDFFs (111 patients, median age 82 years (interquartile range (IQR) 75 to 88), 86% female) with 32 (29%) Su classification 1, 37 (34%) Su 2, and 40 (37%) Su 3 fractures were included. The median follow-up was 2.5 years (IQR 1.2 to 5.0). DP, SP, and DFA were used in 15, 66, and 30 patients, respectively. Compared to SP, patients treated with DP were more likely to have metaphyseal comminution (47% vs 14%; p = 0.009), to be low fractures (47% vs 11%; p = 0.009), and to be anatomically reduced (100% vs 71%; p = 0.030). Patients selected for DFA displayed comparable amounts of medial/metaphyseal comminution as those who underwent DP. At a minimum follow-up of two years, revision surgery for failure was performed in 11 (9.9%) cases at a median of five months (IQR 2 to 9): 0 DP patients (0%), 9 SP (14%), and 2 DFA (6.7%) (p = 0.249).

Conclusion

Using a strategy of DP fixation in fractures, where the fracture was low but there was enough distal bone to accommodate locking screws, and where there is metaphyseal comminution, resulted in equivalent survival free from revision or reoperation compared to DFA and SP fixation.

Management of Bone Loss in Revision Total Knee Arthroplasty: An International Consensus Symposium

The evaluation, classification, and treatment of significant bone loss after total knee arthroplasty (TKA) continue to be a complex and debated topic in revision TKA (rTKA). Despite the introduction of new evidence and innovative technologies aimed at addressing the approach and care of severe bone loss in rTKA, there is no single document that systematically incorporates these newer surgical approaches. Therefore, a comprehensive review of the treatment of severe bone loss in rTKA is necessary. The Stavros Niarchos Foundation Complex Joint Reconstruction Center Hospital for Special Surgery, dedicated to clinical care and research primarily in revision hip and knee replacement, convened a Management of Bone Loss in Revision TKA symposium on June 24, 2022. At this meeting, the 42 international invited experts were divided into groups; each group was assigned to discuss questions related to 1 of the 4 topics: (1) assessing preoperative workup and imaging, anticipated bone loss, classification system, and implant surveillance; (2) achieving durable fixation in the setting of significant bone loss in revision TKA; (3) managing patellar bone loss and the extensor mechanism in cases of severe bone loss; and (4) considering the use of complex modular replacement systems: hinges, distal femoral, and proximal tibial replacements. Each group came to consensus, when possible, based on an extensive literature review and interactive discussion on their group topic. This document reviews each these 4 areas, the consensus of each group, and directions for future research.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Treatment of periprosthetic knee infection and coexistent periprosthetic fracture: A case report and literature review

BACKGROUND

Periprosthetic joint infection (PJI) and periprosthetic fracture (PPF) are among the most serious complications following total knee arthroplasty. Herein, we present one patient with these two complications with details on the characteristics, treatment strategy, and outcome.

CASE SUMMARY

A 69-year-old female patient who suffered from PJI and PPF following total knee arthroplasty was treated by a two-stage revision surgery. After thorough foreign material removal and debridement, we used a plate that was covered with antibiotic-loaded bone cement to link with a hand-made cement spacer to occupy the joint space and fix the fracture. Although the infection was cured, the fracture did not heal and caused bone defect due to the long interval between debridement and revision. In the revision surgery, a cemented stem and cortical allogenic splints were used to reconstruct the fracture and bone defect. At the final follow-up 27 mo after revision, the patient was satisfied with postoperative knee functions with satisfactory range of motion (104º) and Hospital for Special Surgery knee score (82 points). The radiographs showed no loosening of the prosthesis and that the bone grafts healed well with the femur.

CONCLUSION

Our two-stage revision surgery has proved to be successful and may be considered in other patients with PJI and PPF.

Clinical Outcomes Following Distal Femur Replacement for Periprosthetic Distal Femur Fractures: A Systematic Review and Meta-Analysis

BACKGROUND

Management of periprosthetic distal femur fractures (PDFFs) is often complicated by poor bone quality and limited bone stock making fixation attempts challenging and prone to failure. Distal femoral replacement (DFR) is being used to treat such injuries although outcome data are mostly from small case series. We sought to systematically review the literature on DFR for PDFF to summarize their outcomes.

METHODS

PubMed, MEDLINE (EBSCO), and Cochrane Central Database were searched to identify reports of PDFFs treated with DFR. Articles reporting on 5 or more knees were systematically reviewed for clinical function, complications, and mortality. Random effects meta-analysis was used to create summary estimates and publication bias also assessed.

RESULTS

Of 287 identified and screened articles, 15 were included, 14 retrospective, reporting on 352 knees. Following DFR, 87% (95% confidence interval [CI] 71-95) of patients were able to ambulate. The mean postoperative Knee Society Score was 80 (95% CI 77-84). The risk of periprosthetic joint infection was 4.3% (95% CI 2.2-8.2). One-year postoperative mortality rate was 10% (95% CI 6-18). There was some evidence of publication bias with a trend toward smaller studies reporting lower infection risk and mortality.

CONCLUSION

DFR for PDFFs is associated with high functional outcomes and a relatively modest risk of infection. The periprosthetic joint infection and 1-year mortality rates reported here should be considered lower bounds estimates due to publication bias and loss to follow-up. Further investigation of long-term outcomes following DFR for PDFFs is warranted though short-term functional outcomes are promising.