Knee arthrodesis versus above-the-knee amputation after septic failure of revision total knee arthroplasty: comparison of functional outcome and complication rates

Knee arthrodesis with modular megaprosthesis as salvage procedure for the limb following in a patient with an infected knee tumor prosthesis: A case report

Introduction

The management of periprosthetic knee infections is a complex event, especially in the context of megaprostheses. An accepted option in these cases is knee arthrodesis, aiming to salvage the limb with acceptable and pain-free functionality. We present a successful case of knee arthrodesis using a hybrid model of modular nail-prosthesis in a patient with massive bone stock loss following the removal of an infected tumor-type prosthesis.

Case presentation

A 65-year-old male patient with a chronic periprosthetic infection related to a resection prosthesis implanted 5 years earlier, experiencing knee stiffness and presenting a massive bone stock deficit after prosthesis removal. Initial management involved an osteo-cement spacer and antibiotics, along with a transarticular external fixator. Subsequently, knee arthrodesis was performed using a hybrid model of modular nail-prosthesis, coupled with targeted antibiotic treatment. The arthrodesis was deemed successful, with a pain-free limb and no signs of infection recurrence at the 52-month follow-up.

Conclusion

In the scenario of infection and massive bone stock deficit, knee arthrodesis using intramedullary devices such as nails, megaprostheses, or hybrids is an alternative that can be successful if accompanied by appropriate medical-surgical management of the infection. This approach allows for earlier functional recovery compared to other techniques.

Floating Knee Arthrodesis After Periprosthetic Knee Infection: A Multi-Center Study

BACKGROUND

Knee arthrodesis is a means of avoiding above-knee amputation after a periprosthetic joint infection (PJI). The objective of this study was to analyze the results of floating knee arthrodesis in patients who had a history of a periprosthetic knee infection and to perform an external validation of the Baeza-Ortega scale. The analysis consisted of determining reinfection rates, functional results, and the survival of arthrodesis.

METHODS

There were 86 patients who had undergone floating knee arthrodesis in cases of PJI who were retrospectively included in the study. The operations were performed between 2012 and 2022 at three different referral centers for complex bone and joint infections in Spain. In addition to being evaluated clinically, analytically, and radiographically, the patients were assessed functionally with the Baeza-Ortega scale, which had been previously validated. At a mean follow-up of 4 years (range, 1 to 9), 13 patients suffered reinfection (15%) and 29% of patients experienced complications with an average of 42 months until a complication appeared.

RESULTS

The recurrence of infection was not observed to be significantly affected by sex (P = 0.13), age (P = 0.1), or the type of surgery previously undergone (P = 0.17), nor was the McPherson Host Grade (P = 0.4) observed to have a significant effect. Patients who had a McPherson Limb Grade 3 were more likely to suffer reinfection than those with a McPherson Limb Grade 2 (P = 0.036). There were 45 patients (53%) who were fully evaluated and scored. For 16 patients (35%), the results were evaluated as excellent, for 22 (48%) acceptable, for six (14%) low, and for one (3%) poor. There was a significant correlation between patient satisfaction and functional outcomes (P = 0.0006).

CONCLUSIONS

The arthrodesis nail without bone-bone fusion is an effective and safe procedure for patients who have a recurrent PJI, providing satisfactory functional results when a knee prosthesis revision cannot be performed.

Knee fusion versus above knee amputation as two options to deal with knee periprosthetic joint infection

BACKGROUND

Periprosthetic joint infection (PJI) poses a significant challenge in total knee arthroplasty (TKA), with recurrence rates as high as 14-28%, leading to substantial morbidity and treatment costs. When conventional treatments fail, knee fusion and above-the-knee amputation (AKA) emerge as alternative options. Existing literature offers conflicting views on the efficacy and impact of knee fusion versus AKA with varied outcomes and limitations.

METHODS

This retrospective national study spanning 2010-2022 investigates Knee Fusion and AKA as options for addressing Knee PJI. Utilizing PearlDiver Patient Records Database, procedural, and reimbursement data on over 100 million individuals from all the US was evaluated. Readmission rates, costs, and complications of the mentioned procedures were assessed using ICD-9 and ICD-10 codes within a 90-day period and one-year post-operation. Statistical analyses, including chi-square tests and regression models, were conducted using integrated R software.

RESULTS

The study reveals a substantial escalation (p < 0.0001) in the proportion of patients opting for AKA compared to arthrodesis. While age as a demographic factor showed no significant difference, arthrodesis patients exhibited lower comorbidity scores (3.6 ± 2.9 vs. 4.6 ± 3.4, p < 0.001). Arthrodesis correlated with higher 90-day thromboembolism rates (9.2% vs. 7.3%, p < 0.001), blood transfusion requirements (23.2% vs. 14.4%, p < 0.001), and acute renal failure incidence (p = 0.008) but demonstrated lower rates of urinary tract infections (p = 0.047) and cerebrovascular accidents (p < 0.001). At 1 year, arthrodesis was associated with higher infection rates (38.7% vs. 36.4%, p < 0.001). Arthrodesis patients had significant increased 90-day and 1-year readmission rates and hospitalization costs ($12,732 vs. $18,826, p < 0.001).

CONCLUSIONS

We found higher rates of 1-year thromboembolism, infection, acute renal failure, and readmission in the arthrodesis group. AKA patients had more sepsis and cerebrovascular accidents. A patient-centered conversation is best for persistent infections and failed revision TKA. Considering the patient's quality of life, goals, and health status, this discussion should cover each procedure's risks and complications.

Clinical and Functional Outcomes of Knee Arthrodesis by Charnley's External Fixator

Background Knee arthrodesis was originally developed to manage severe joint infections such as tuberculosis before the advent of antibiotics and joint replacement techniques. The procedure aims to eliminate pain and infection by stabilizing the knee joint through bone fusion. Knee arthrodesis remains essential for cases where total knee arthroplasty is not feasible, such as in patients with severe bone loss, chronic infections, or failed knee replacements. Many studies have demonstrated fusion by external fixators because infection is the most common indication of this procedure. We studied knee arthrodesis using Charnley's compression clamps which are easy to apply and economical. Methodology A prospective observational study was conducted on 15 patients for 18 months. Patients with an infection in the knee joint (septic or tuberculous), failed total joint arthroplasty, failed fracture fixation around the knee joint, and neuropathic joints were included in the study. Patients were evaluated using the pre and postoperative Knee Society Score and Knee Society Score (Functional). Results In the study, 80% of the patients were males. Septic arthritis and tuberculosis were common indications for the surgery. More than 70% of the patients were previously operated on the same knee joint. The duration of the fixator ranged from 32 weeks to 39 weeks (7.47 months to 9.1 months) with an average of 35.73 weeks (8.34 months). The final follow-up period ranged from 9.5 to 18 months with an average of 14.1 months. The knee score ranged preoperatively from 5 to 22 (average = 16.2) and improved postoperatively ranging from 50-56 (average = 54). The functional score ranged preoperatively from 40 to 50 (average = 43.60) and improved postoperatively ranging from 80 to 100 (average = 89.66). Conclusions The fusion by Charnley's external clamps is easy, cost-effective, and comfortable for the patients. The complications are relatively fewer and the success rate of the fusion is higher with this treatment method.

The Mark Coventry Award: PhotothermAA Gel Combined With Debridement, Antibiotics, and Implant Retention Significantly Decreases Implant Biofilm Burden and Soft-Tissue Infection in a Rabbit Model of Knee Periprosthetic Joint Infection

BACKGROUND

Chronic periprosthetic joint infection (PJI) is a major complication of total joint arthroplasty. The underlying pathogenesis often involves the formation of bacterial biofilm that protects the pathogen from both host immune responses and antibiotics. The gold standard treatment requires implant removal, a procedure that carries associated morbidity and mortality risks. Strategies to preserve the implant while treating PJI are desperately needed. Our group has developed an anti-biofilm treatment, PhotothermAA gel, which has shown complete eradication of 2-week-old mature biofilm in vitro. In this study, we tested the anti-biofilm efficacy and safety of PhotothermAA in vivo when combined with debridement, antibiotics and implant retention (DAIR) in a rabbit model of knee PJI.

METHODS

New Zealand white rabbits (n = 21) underwent knee joint arthrotomy, titanium tibial implant insertion, and inoculation with Xen36 (bioluminescent Staphylococcus aureus) after capsule closure. At 2 weeks, rabbits underwent sham surgery (n = 6), DAIR (n = 6), or PhotothermAA with DAIR (n = 9) and were sacrificed 2 weeks later to measure implant biofilm burden, soft-tissue infection, and tissue necrosis.

RESULTS

The combination of anti-biofilm PhotothermAA with DAIR significantly decreased implant biofilm coverage via scanning electron microscopy compared to DAIR alone (1.8 versus 81.0%; P < .0001). Periprosthetic soft-tissue cultures were significantly decreased in the PhotothermAA with DAIR treatment group (log reduction: Sham 1.6, DAIR 2.0, combination 5.6; P < .0001). Treatment-associated necrosis was absent via gross histology of tissue adjacent to the treatment area (P = .715).

CONCLUSIONS

The addition of an anti-biofilm solution like PhotothermAA as a supplement to current treatments that allow implant retention may prove useful in PJI treatment.

Above-knee amputation shows higher complication and mortality rates in line with lower functional outcome compared to knee arthrodesis in severe periprosthetic joint infection

Aims

In cases of severe periprosthetic joint infection (PJI) of the knee, salvage procedures such as knee arthrodesis (KA) or above-knee amputation (AKA) must be considered. As both treatments result in limitations in quality of life (QoL), we aimed to compare outcomes and factors influencing complication rates, mortality, and mobility.

Methods

Patients with PJI of the knee and subsequent KA or AKA between June 2011 and May 2021 were included. Demographic data, comorbidities, and patient history were analyzed. Functional outcomes and QoL were prospectively assessed in both groups with additional treatment-specific scores after AKA. Outcomes, complications, and mortality were evaluated.

Results

A total of 98 patients were included, 52 treated with arthrodesis and 47 with AKA. The mean number of revision surgeries between primary arthroplasty and arthrodesis or AKA was 7.85 (SD 5.39). Mean follow-up was 77.7 months (SD 30.9), with a minimum follow-up of two years. Complications requiring further revision surgery occurred in 11.5% of patients after arthrodesis and in 37.0% of AKA patients. Positive intraoperative tissue cultures obtained during AKA was significantly associated with the risk of further surgical revision. Two-year mortality rate of arthrodesis was significantly lower compared to AKA (3.8% vs 28.3%), with age as an independent risk factor in the AKA group. Functional outcomes and QoL were better after arthrodesis compared to AKA. Neuropathic pain was reported by 19 patients after AKA, and only 45.7% of patients were fitted or were intended to be fitted with a prosthesis. One-year infection-free survival after arthrodesis was 88.5%, compared to 78.5% after AKA.

Conclusion

Above-knee amputation in PJI results in high complication and mortality rates and poorer functional outcome compared to arthrodesis. Mortality rates after AKA depend on patient age and mobility, with most patients not able to be fitted with a prosthesis. Therefore, arthrodesis should be preferred whenever possible if salvage procedures are indicated.

Constraint degree in revision total knee replacement: a registry study on 1432 patients

PURPOSE

Total knee replacement (TKR) failure represents a hard challenge for knee surgeons. TKR failure can be managed in revision with different constraint, related with soft and bone knee damages. The choice of the right constraint for every failure cause represents a not summarized entity. The purpose of this study is identifying distribution of different constraints in revision TKR (rTKR) for failure cause and the overall survival.

METHODS

A registry study based on the Emilia Romagna Register of the Orthopaedic Prosthetic Implants (called RIPO) was performed with a selection of 1432 implants, in the period between 2000 and 2019. Selection implants including primary surgery constraint, failure cause and constraint revision for every patient, and divided for constraint degrees used during procedures (Cruciate Retaining-CR, Posterior Stabilized-PS, Condylar Constrained Knee-CCK, Hinged).

RESULTS

The most common cause of primary TKR failure was aseptic loosening (51,45%), followed by septic loosening (29,12%). Each type of failure was managed with different constraint, the most used was CCK in the most of failure causes, such as to manage aseptic and septic loosening in CR and PS failure. Overall survival of TKA revisions has been calculated at 5 and 10 years for each constraint, with a range of 75.1-90.0% at 5 years and 75.1-87.5% at 10 years.

CONCLUSION

Constraint degree in rTKR is typically higher than primary, CCK is the most used constraint in revision surgery with an overall survival of 87.5% at 10 years.

Transfemoral amputation versus knee arthrodesis for failed total knee replacement: A systematic review of outcomes

BACKGROUND

The options available to salvage a failed total knee replacement (TKR) include transfemoral amputation (TFA) and knee arthrodesis (KA). This systematic review aims to evaluate outcomes following either TFA or KA, comparing ambulatory status, additional subsequent surgery, postoperative infection, pain, health-related quality of life (HRQoL), and mortality rate.

METHODS

A literature search was conducted in EMBASE, Ovid Medline, and PubMed. Only primary research studies were included and data were independently extracted using a standardized form. The methodological quality of the studies was evaluated using Newcastle-Ottawa Scale.

RESULTS

Forty-four papers were included, comprising 470 TFA and 1034 KA patients. The methodological quality of the studies was moderate. No TFA versus KA randomized controlled trials could be identified. Pooled data totals via subgroup analyses were performed, owing to inconsistent reporting methods in the included studies. Prosthesis use rate by TFA patients was 157/316 = 49.7%. Significant differences included that TFA patients had lower rates of ambulatory capacity than KA patients (139/294 = 45.6% versus 248/287 = 86.4%, p < 0.001), TFA ambulators were less likely to use an ambulatory aid (55/135 = 40.7% versus 167/232 = 72.0%, p < 0.001), and TFA was associated with a greater postoperative infection rate than KA (29/118 = 24.6% versus 129/650 = 17.2%, p = 0.054). There was a similar rate of revision surgery between TFA and KA (37/183 = 20.2% versus 145/780 = 18.6%, p = 0.612). Data on HRQoL for both TFA and KA were limited, contradictory, and heterogeneous.

CONCLUSION

No randomized controlled trials comparing TFA versus KA exist;therefore, current data likely reflects substantial selection bias. The currently available evidence suggests that KA patients are significantly more likely to achieve independent bipedal ambulation than TFA patients. In both treatment cohorts, subsequent infection and revision surgery remain a relatively common occurrence.

Floating Knee Arthrodesis After Prosthetic Knee Infection: A Report of 48 Cases

BACKGROUND

Knee arthrodesis is a means of avoiding above-knee amputation after a prosthetic joint infection (PJI). The objective of this study was to analyze the results of floating knee arthrodesis in patients who had a history of aprosthetic knee infection. The analysis consisted of determining reinfection rates, functional results, and the survival of arthrodesis.

METHODS

There were 48 patients who underwent a cemented floating knee arthrodesis in cases of PJI retrospectively included in the study, having been operated on between 2012 and 2020. In addition to being evaluated clinically, analytically, and radiographically, the patients were assessed functionally by means of a newly-created scale.

RESULTS

At a mean follow-up of 4 years (1 year to 9 years), 7 patients suffered reinfection (14.6%). The recurrence of infection was not observed to be significantly affected by sex (P = .16), age(P = .09), or the type of surgery previously undergone (P = .18), nor was the McPherson Host Grade (P = .4) observed to have a significant effect. Patients who had a McPherson Limb Grade 3 were more likely to suffer reinfection than those with a McPherson Limb Grade 2 (P = .034). There were 26 patients (54%)fully evaluated and scored on the Knee Arthrodesis Functional Scale(BAOR). For 11 patients (42%), the results were evaluated as excellent, for 11 (42%) acceptable, for 3 (12%) low, and for 1(4%) poor.

CONCLUSION

The arthrodesis nail is an effective and safe procedure for patients who have a recurrent PJI, providing an effective alternative when the criteria for a new revision total knee arthroplasty are not met.

Modular Knee Arthrodesis as Definitive Treatment for Periprosthetic Infection, Bone Loss, and Failure of the Extensor Mechanism After Total Knee Arthroplasty

Background

Periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) can result in bone and soft-tissue loss, leg length discrepancies, and dysfunctional extensor mechanisms. While above-knee amputation (AKA) is an established salvage treatment, modular knee arthrodesis (MKA) is a viable option that provides rigid stability and maintains leg length even in patients with severe bone and soft-tissue loss. We sought to report the outcomes of patients with an MKA as the definitive treatment.

Methods

We retrospectively reviewed 8 patients implanted with an MKA at 2 institutions between 2016 and 2022. The mean age was 69.63 years, and 50.0% of patients were women. All patients were indicated for conversion to an MKA as the definitive treatment in the setting of treated chronic PJI after TKA, severe bone loss, and failure of the extensor mechanism not amenable to repair. Medical records and radiographs were reviewed.

Results

No patients required incision and drainage or exchange of their MKA for PJI at mean 2-year follow-up. One patient required 2 revisions for mechanical failure of his implant at 5.0 and 6.4 years postoperatively.

Conclusions

MKA is a viable permanent alternative to AKA for patients with treated chronic PJI and dysfunctional extensor mechanism after TKA. The procedure restores leg lengths in the setting of severe bone and soft-tissue loss, therefore allowing patients to ambulate independently. Still, surgeons should be aware of the potential for mechanical failure requiring revision.

Periprosthetic joint infection and immunity: Current understanding of host-microbe interplay

Periprosthetic joint infection (PJI) is a major complication of total joint arthroplasty. Even with current treatments, failure rates are unacceptably high with a 5-year mortality rate of 26%. Majority of the literature in the field has focused on development of better biomarkers for diagnostics and treatment strategies including innovate antibiotic delivery systems, antibiofilm agents, and bacteriophages. Nevertheless, the role of the immune system, our first line of defense during PJI, is not well understood. Evidence of infection in PJI patients is found within circulation, synovial fluid, and tissue and include numerous cytokines, metabolites, antimicrobial peptides, and soluble receptors that are part of the PJI diagnosis workup. Macrophages, neutrophils, and myeloid-derived suppressor cells (MDSCs) are initially recruited into the joint by chemokines and cytokines produced by immune cells and bacteria and are activated by pathogen-associated molecular patterns. While these cells are efficient killers of planktonic bacteria by phagocytosis, opsonization, degranulation, and recruitment of adaptive immune cells, biofilm-associated bacteria are troublesome. Biofilm is not only a physical barrier for the immune system but also elicits effector functions. Additionally, bacteria have developed mechanisms to evade the immune system by inactivating effector molecules, promoting killing or anti-inflammatory effector cell phenotypes, and intracellular persistence and dissemination. Understanding these shortcomings and the mechanisms by which bacteria can subvert the immune system may open new approaches to better prepare our own immune system to combat PJI. Furthermore, preoperative immune system assessment and screening for dysregulation may aid in developing preventative interventions to decrease PJI incidence.

Early results of a novel modular knee arthrodesis implant after uncontrolled periprosthetic knee joint infection

AIM

The aim of this study is to evaluate the functional outcomes and complications after non-fusion knee arthrodesis with a modular segmental intramedullary implant used for infected total knee arthroplasty revisions.

METHODS

A retrospective review of the patients who had been surgically treated with a modular intramedullary arthrodesis implant for recurrent infection after revision TKA between January 2016 and February 2020 were included. The indications for arthrodesis were failed infected TKA with massive bone loss, deficient extensor mechanism and poor soft tissue coverage that precluded joint reconstruction with revision TKA implants. Clinical outcomes were assesed with visual analogue scale for pain (pVAS), Oxford knee score (OKS) and 12-item short form survey (SF-12). Full-length radiographs were used to verify limb length discrepancies (LLD).

RESULTS

Fourteen patients (4 male and 10 female) patients with a mean age of 69.3 (range, 59 to 81) years at time of surgery were available for final follow-up at a mean of 28.8 months (range, 24-35 months). All clinical outcome scores improved at the final follow-up (pVAS, 8.5 to 2.6, p = .01; OKS, 12.6 to 33.8, p = .02; SF-12 physical, 22.9 to 32.1, p = .01 and SF-12 mental, 27.7 to 40.2, p = .01). The mean LLD was 1.0 cm (range, + 15 - 2.3 cm). Re-infection was detected in three patients (21.4%). Two patients were managed with suppressive antibiotic treatment and a third patient required repeat 2-stage revision procedure. In one patient, a periprosthetic femur fracture was observed and treated with plate osteosynthesis.

CONCLUSION

Uncontrolled infection after total knee arthroplasty can be effectively treated with arthrodesis using a modular intramedullary nail and satisfactory functional results can be obtained.

LEVEL OF EVIDENCE

Level 4, Retrospective cohort study.

A comparison of outcomes for above-knee-amputation and arthrodesis for the chronically infected total knee arthroplasty: a systematic review

INTRODUCTION

Several strategies have been shown to have some efficacy in the chronically infected total knee arthroplasty (TKA): chronic antibiotic suppression, a second two-stage revision, arthrodesis, and above-the-knee amputation (AKA). We conducted a systematic review to determine the efficacy of these treatments in patients who had previously received a two-stage revision.

METHODS

A systematic review of the literature was performed which investigated PubMed, Embase, Scopus, and Web of Science Databases. Chronic infection was defined as a persistent infection of a TKA after a previous two-stage revision. Studies were independently evaluated by two reviewers. Quality appraisal was performed using MINORS Criteria.

RESULTS

14 studies were included for the final review. For chronically infected TKA, a second two-stage revision was often sufficient to control infection. If revision failed, the most common next procedure was either a repeat revision or AKA. AKA patients had less pain and higher quality of life scores compared to arthrodesis, but a higher five-year mortality rate.

DISCUSSION AND CONCLUSION

Chronic infection in TKA offers a multitude of challenges for orthopedic surgeons. We found that arthrodesis and AKA were not significantly different in rates of infection eradication or quality of life. We recommend clinicians to actively discuss options with patients to find a procedure most suitable for them.

Mortality, patient-reported outcome measures, and the health economic burden of prosthetic joint infection

Prosthetic joint infection (PJI) is one of the most devastating complications for a patient following arthroplasty. This scoping review aims to evaluate the burden of PJI on individual patients and the healthcare system regarding the mortality rate, patient-reported quality of life, and healthcare resource utilisation. Patients with PJI have up to a five-fold higher mortality rate than those who have undergone an uninfected primary arthroplasty. There is an increased use of ambulatory aids and reduced joint function scores in patients with PJI. Global quality of life is poorer, specifically measured by the EQ-5D. Direct hospitalisation costs are two- to five-fold higher, attributed to surgery and prostheses, antibiotics, and a prolonged inpatient stay. There is an immense clinical and health economic burden secondary to PJI worldwide. This is expected to rise exponentially due to the increasing number of primary procedures and an ageing population with comorbidities Improving preventative and treatment strategies is imperative for patients and the healthcare system.

Functional Outcome of Above-Knee Amputation After Infected Total Knee Arthroplasty

Background

Periprosthetic joint infection is a serious complication of total knee arthroplasty (TKA). Management usually involves irrigation and debridement, polyethylene liner exchange, one-stage revision, two-stage revision, knee arthrodesis, or ultimately above-knee amputation (AKA). We present our experience with 21 patients who underwent AKA as a sequela of unresolved infected TKA, highlighting their etiology and functional outcomes.

Methods

A retrospective chart review was performed for all cases of infected TKA treated with AKA at 1 institute from January 2007 to December 2020, with a minimum follow-up of 1 year. Patient demographics, Charlson comorbidity index, culture results, ambulation status, prosthesis fitting, and functional outcomes were collected. Short Form-36 and activities of daily living questionnaires were used for functional outcome assessment.

Results

Twenty-one patients were identified, 7 of whom were male (33.3%). Mean ± standard deviation follow-up was 5.7 ± 3.1 years (range, 1-11 years). Mean ± standard deviation age was 57.9 ± 10.7 years (range, 38-87 years), and the mean body mass index was 33.5 ± 6.4 kg/m2 (range, 25.4-46 kg/m2). Gram-positive organisms were identified in 15 cases (66.7%). Prosthesis fitting was successful in 17 patients (81%). Post-AKA ambulation was achieved in 12 patients (57.1%). The ambulating group showed higher Short Form-36 and activities of daily living scores when compared with patients who did not ambulate (60.2 vs 43.3, P = .041, and 67.2 vs 52.7, P = .029, respectively).

Conclusions

AKA should be considered solely as the final recourse for infected TKA. Despite the low-to-moderate patient-reported postoperative outcomes, prosthesis fitting and maintaining ambulation can improve postoperative functional outcomes.

Enough is enough: salvage procedures in severe periprosthetic joint infection

BACKGROUND

In severe cases of periprosthetic joint infection involving negative host-dependent factors, individual-based decisions between a curative therapy vs. salvage procedure are necessary. We aimed to review salvage procedures in severe periprosthetic joint infection cases, where a gold standard of a curative two-stage exchange can no longer be achieved. The options of knee arthrodesis, amputation, persistent fistula (stable drainage), or a debridement, antibiotics, and implant retention procedure in late-onset cases are discussed, including lifelong antibiotic suppression alone.

METHODS

We focused on known salvage procedures for severe periprosthetic joint infection of the hip and knee, such as amputation, arthrodesis, antibiotic suppression, persistent fistula, and debridement, antibiotics, and implant retention in late-stage infections, and the role of local antibiotics. The current literature regarding indications and outcomes was reviewed.

RESULTS

Whereas a successful single-stage above-knee amputation can be a curative effort in younger patients, this is associated with limited outcome in older patients, as the proportion who receive an exoprosthesis leading to independent mobility is low. Therefore, arthrodesis using an intramedullary modular nail is an option for limb salvage, pain reduction, and preservation of quality of life and everyday life mobility, when revision total knee arthroplasty is not an option. Carrying out a persistent fistula using a stable drainage system, as well as a lifelong antibiotic suppression therapy, can be an option, in cases where no other surgery is possible. Active clinical surveillance should then be carried out. A debridement, antibiotics, and implant retention procedure in combination with local degradable antibiotics can be used and is an encouraging new option, but should not been carried out twice.

CONCLUSION

Whereas the gold standard in periprosthetic joint infection treatment of late infections remains the exchange of the prosthesis, salvage procedures should be considered in the cases of reduced life expectancy, several recurrences of the infection, patients having preference and negative host factors. In these cases, the appropriate salvage procedure can temporarily lead to remission of the infection and the possibility to maintain mobility.

Does the Implementation of the PRO-IMPLANT Foundation Treatment Algorithm Improve the Outcome of Chronic Periprosthetic Knee Infections? Mid-Term Results of a Prospective Study

BACKGROUND

Several treatment options for chronic periprosthetic joint infections have been published in the current literature, with an on-going discussion to determine effective management algorithms.

OBJECTIVES

To compare outcomes of the two-stage exchange procedure in revision TKA prior to and after implementation of the PRO-IMPLANT Foundation treatment algorithm. The primary endpoints were defined as (i) revisions during the interval time, (ii) duration of the interval time and (iii) successful PJI eradication.

MATERIAL AND METHODS

Between 02/2013 and 09/2016, 122 patients were included in a single-centre cohort analysis. 55 patients were treated according to the previously used algorithm (K1) and 67 according to the PRO-IMPLANT Foundation algorithm (K2). A minimum follow-up period of 3 years was set as the inclusion criterion. Successful eradication of infection was defined in accordance with the consensus criteria by Diaz-Ledezma et al. RESULTS: Successful eradication was achieved in 42 (67%) patients in K1 and 47 (85.5%) in K2 (p ≤ 0.005). The mean interval time was 88 days (range 51 - 353) in K1 and 52 days (range 42 - 126) in K2 (p ≤ 0.005). In K1, a mean of 0.8 (range 0 - 6) revisions were necessary during the interval period compared with 0.5 (range 0 - 4) in K2 (p = 0.066).

CONCLUSION

Implementation of the PRO-IMPLANT treatment algorithm led to significant improvement in the outcome of periprosthetic joint infections. During mid-term follow-up, infection eradication was highly successful, with decreases in the interval time as well as the number of revisions.

The impact of knee arthrodesis on gait kinematics, muscle activity and patient-reported outcome

BACKGROUND

The aim of this retrospective study was to analyze gait kinematicsandoutcome parameters after knee arthrodesis.

METHODS

Fifteenpatients with a mean follow-up of 5.9 (range0.8-36) years after unilateral knee arthrodesis were included. A 3D gait analysis was performed and compared to a healthy control group of14patients. Comparative electromyography was performed bilaterally at the rectus femoris, vastuslateralis/medialisand tibialis anterior muscles. The assessment further included standardized outcome scores- Lower Extremity Functional Scale (LEFS) andShort Form Health Survey (SF-36).

RESULTS

The 3D analysis showed a significantly shortened stance phase (p = 0.000), an extended swing phase (p = 0.000), and an increased time per step (p = 0.009) for the operated side compared with thenonoperatedside. There were statistically significant differences in the extent of movement of the hips, knees and ankles among the operated andnonoperatedsides and the control group. For the mean EMG measurement, no significant difference was found between the healthy control group and the patients with arthrodesis.The average LEFSscorewas 27.5 ± 10.6out of a maximum of 80 points,and the mean physical total scale and mean emotional total scale scores for the SF-36 were 27.9 ± 8.5and 52.9 ± 9.9, respectively.

CONCLUSIONS

Arthrodesis of the knee joint causes significant kinematic changes in gait pattern,and patients achieve poor results in subjective and functional outcomes(SF- 36, LEFS).Arthrodesis ensures that the extremities are preserved and can enable walking, but it must be viewed as a severe handicap for the patient.

Knee Arthrodesis: An Analysis of Surgical Risk Factors and Complications Using a National Database

Background

Knee arthrodesis is predominantly a salvage procedure. In present time, knee arthrodesis is mostly considered for cases of unreconstructable failed total knee arthroplasty after prosthetic joint infection or trauma. Knee arthrodesis has shown better functional outcomes than amputation for these patients but has a high complication rate. The purpose of this study was to characterize the acute surgical risk profile of patients undergoing a knee arthrodesis for any indication.

Methods

The American College of Surgeons National Surgical Quality Improvement Program database was queried to determine 30-day outcomes after knee arthrodesis between 2005 and 2020. Demographics, clinical risk factors, and postoperative events were analyzed, along with reoperation and readmission rates.

Results

A total of 203 patients that underwent a knee arthrodesis were identified. Forty-eight percent of patients had at least 1 complication. The most common complication was acute surgical blood loss anemia requiring a blood transfusion (38.4%), followed by organ space surgical site infection (4.9%), superficial surgical site infection (2.5%), and deep vein thrombosis (2.5%). Smoking was associated with higher rates of reoperation and readmission (odds ratio 9, P < .01, and odds ratio 6, P < .05).

Conclusions

Overall, knee arthrodesis is a salvage procedure that has a high rate of early postoperative complications and is most often performed in patients at higher risk. Early reoperation is strongly associated with a poor preoperative functional status. Smoking places patients at higher risk of early complications.

Elective transfemoral amputation and simultaneous implantation of a transcutaneous osseointegrated prosthesis stem as salvage treatment after knee joint arthrodesis with poor function: A case report

Background

Surgical reconstruction of anterior cruciate ligament ruptures is a well-established procedure, and although it is for the vast majority of patients without severe complications, total knee joint arthroplasty, arthrodesis of the knee, and finally transfemoral amputation have to be considered in the worst-case scenario.

The case

We report a case of a patient with a 13-year history of recurrent failure after anterior cruciate ligament reconstruction. She claimed she had severely impaired mobility secondary to a knee joint arthrodesis via an Ilizarov circular frame 2 years ago and chronic immobilizing pain, making a permanent medication with opioids necessary. She was aware of the therapeutic options and asked for transfemoral amputation and concomitant supply with a transcutaneous osseointegrated prosthesis system (TOPS).

Procedures

After careful evaluation and clinical work-up, the indication for transfemoral amputation and concomitant implantation of the prosthetic stem into the femoral cavity was secured. Six weeks after the creation of the stoma for coupling of the artificial limb and onset of physiotherapy, balance and gait training were scheduled. Full weight-bearing and walking without crutches were allowed 12 weeks after the index procedure. This sequence of events was paralleled by a series of pre-defined examinations, that is, questionnaires and mobility scores addressing the situation of transfemoral amputees, as well as standardized clinical gait analysis. The latter was performed before surgery and 6, 9, and 18 months after the index procedure.

Outcome

At the time of the index procedure, opioids could be tapered to zero, and the patient quickly regained her walking abilities during the rehabilitation period. Clinical gait analysis confirmed the restoration of bilateral symmetry by mutual approximation of kinematics and kinetics to a standard gait pattern.

Conclusion

The outcome of our patient strengthens the therapeutic potential of a unilateral transfemoral amputation in combination with TOPS. Nevertheless, long-term follow-up is necessary to detect future complications of this approach.

National Decline in Knee Fusions Performed for Salvage of Chronic Periprosthetic Total Knee Infections

The primary purpose of this study was to study and compare rates of two salvage operations for patients with chronically infected total knee arthroplasties: (1) knee arthrodesis and (2) above knee amputation (AKA). An analysis was performed comparing the inpatient hospital characteristics and complications between the two procedures. Secondarily, we presented rates of all surgically treated periprosthetic total knee infections over a 6-year period. Using the Nationwide Inpatient Sample, we identified all patients with a periprosthetic infection (International Classification of Diseases, Ninth Revision [ICD-9] 996.66) from 2009 to 2014. Subsequently, we identified surgically treated total knee infections through the following ICD-9 codes: 00.80 (all component revision), 00.84 (liner exchange), 80.06 (removal of prosthesis), 84.17 (AKA), and 81.22 (knee fusion). From 2009 to 2014, the annual incidence of surgically treated total knee periprosthetic infections increased by 34.9% nationally, while the annual incidence of primary total knees increased by only 13.9%. Salvage operations (AKA and knee fusion) represented 5.8% of all surgically treated infections. The rate of knee fusions decreased from 1.9% of surgically treated infections in 2009 to 1.4% in 2014 (p < 0.05), while the rate of AKA stayed steady at 4.5% of cases over the 6-year period. Length of stay was significantly shorter in the knee fusion group (7.9 vs. 10.8 days, p < 0.05), but total hospital costs were higher (33,016 vs. 24,933, p < 0.05). In the multivariable adjusted model, patients undergoing knee fusion had significantly decreased odds of being discharged to skilled nursing facility (odds ratio: 0.42, 95% confidence interval: 0.31-0.58). The annual incidence of surgically treated periprosthetic total knee infections is increasing. The rate of knee arthrodesis for chronic periprosthetic total knee infections is decreasing. Reasons for this downward trend in knee fusions should be evaluated carefully as knee fusions have shown to have the potential advantage of improved mobility and decreased patient morbidity for chronic PJI. The level of evidence is III.

Contemporary Outcomes of Transfemoral Amputation After Total Knee Arthroplasty

BACKGROUND

Transfemoral amputation (TFA) is a salvage procedure for unreconstructable failed total knee arthroplasty (TKA). Prior studies have reported poor outcomes, patient survival, and prosthetic use. The purpose of this study was to analyze patient outcomes and prosthetic utilization in a contemporary group of patients undergoing TFA in the setting of a TKA.

METHODS

We reviewed 112 patients undergoing TFA with a prior TKA. Indications for amputation and postoperative functional measures were captured through chart review. Patients were contacted by survey to assess the quality of life. The mean follow-up after TFA was 4 years.

RESULTS

Amputations were performed for a chronically infected TKA (n = 87, 78%) and an ischemic limb without signs of an infected TKA (n = 22, 20%). The 10-year survival after TFA was 21%. Of the patients not lost to follow-up, 53 (47%) patients were fitted for a prosthesis. Patients who underwent a TFA after the year 2000 were more likely to be fit for a prosthesis (odds ratio 7.27, P < .01); however, patients were likely to be ambulatory before TFA than after TFA (odds ratio 3.68, P < .01). After TFA, the mean 12-Item Short Form Survey scores for the mental and physical components were 54 ± 13 and 34 ± 7, with no difference in scores between patients fitted for a prosthesis and those who were not (P > .05).

CONCLUSION

Patients undergoing a TFA after TKA due to failure of the TKA are more likely to be fit for a prosthesis; however, they reported no better quality of life and satisfaction compared with patients not fit for a prosthesis.

LEVELS OF EVIDENCE

Level III, Therapeutic.

Poor Outcome of Above-Knee Amputation after Septic Failure of Revision Total Knee Arthroplasty

Persistent periprosthetic infection following total knee arthroplasty is one of the most dreaded complications of orthopaedic surgery. Treatment strategies include arthrodesis of the knee joint, stable fistula, long-lasting antibiotic therapy, or above-knee amputation. The advantage of amputation in comparison to other treatment options is the possible cure of infection, because the source of infection is removed and no foreign material left in situ. The aim of the study is to examine whether a septic amputation of the femur in case of persistent periprosthetic infection at the knee joint leads to the healing of the patient. Moreover, the physical and mental state should be evaluated. All patients with above-knee amputation because of periprosthetic joint infection after primary total knee arthroplasty between 2016 and 2018 were included in this retrospective study. A questionnaire with the clinical scores visual analog scale, modified Lysholm, Western Ontario and McMaster Universities Osteoarthritis Index and 36-Item Short Form Survey has been designed. In addition, all characteristics and perioperative data were documented. Eleven patients were included in the study. One patient died after above-knee amputation; all other patients live with a marked impairment of quality of life but with absence of the infection of the leg. Two out of ten are able to walk regularly with an exoprosthesis with forearm crutches, 50% are in a wheelchair, while 30% are bedridden. Patients with above-knee amputation after persistent periprosthetic infections were free of infection and without signs of inflammation. However, this is associated with worse mobility and high mortality rate.

Obesity, Comorbidities, and Prior Operations Additively Increase Failure in 2-Stage Revision Total Knee Arthroplasty for Prosthetic Joint Infection

BACKGROUND

Prosthetic joint infection (PJI) of the knee carries significant morbidity, mortality, and economic cost. We hypothesize that obese and poor medical hosts will have a significant and additive increase in failure rate undergoing 2-stage revision total knee arthroplasty for PJI.

METHODS

All 2-stage revision total knee arthroplasty procedures for PJI performed at one institution were identified between 2005 and 2020. In total, 144 patients were included and defined as success or failure based on published criteria regarding infection eradication, further intervention, or mortality. The American Society of Anesthesiologists score and the Charlson Comorbidity Index were utilized to assess host grade. Patient, surgical, and microbiologic variables were investigated with univariable and multivariable analysis to explore association with risk of failure.

RESULTS

In the cohort, 32.4% of patients failed with mean follow-up of 5.1 years. In multivariable analysis, the number of major operations requiring arthrotomy and implantation of new material between the primary and first stage, host grade, and elevated body mass index were the major contributors to failure. Combining these factors, with body mass index >30 and 2 or more major operations, the failure rate increased to 76.5% and 71.4% respectively for American Society of Anesthesiologists score 3 (P ≤ .001) and Charlson Comorbidity Index ≥2 (P ≤ .001).

CONCLUSION

In this cohort, multiple major operations between the primary and first stage, host grade, and obesity were the major contributors to failure. When combining these factors, patients had an additive increase in failure rate. Treatments such as amputation or less invasive options and suppression should be discussed and considered in these patients.

Revision TKA with a distal femoral replacement is at high risk of reinfection after two-stage exchange for periprosthetic knee joint infection

PURPOSE

Megaprosthetic distal femoral reconstruction (DFR) is a limb-salvage procedure to address bone loss following two-stage revision for periprosthetic knee joint infection (PJI). The purpose of this study was to analyze the survival of DFR compared to hinged total knee arthroplasty (TKA). It was hypothesized that DFR was associated with a poorer survival.

METHODS

In this retrospective single-center study, 97 subjects who underwent two-stage revision of chronic knee PJI were included. Among these, 41 were DFR. The diagnosis of PJI was established using the Musculoskeletal Infection Society (MSIS) criteria. Implant survival was calculated using Kaplan-Meier method and compared with the log-rank test as well as multivariate Cox regression at a minimum follow-up period of 24 months.

RESULTS

The median follow-up period was 59 (interquartile range (IQR) 45-78) months. Overall, 24% (23/97) of patients required revision surgery for infection. The infection-free survival of rotating hinge revision TKA was 93% (95% Confidence Interval (CI) 86-100%) at five years compared to 50% (95% CI 34-66%) for DFR. In multivariate analysis, the risk factors for reinfection were DFR reconstruction (HR 4.7 (95% CI 1-22), p = 0.048), length of megaprosthesis (HR 1.006 (95% CI 1.001-1.012), p = 0.032) and higher BMI (HR 1.066, 95% CI 1.018-1.116), p = 0.007). 10% (4/41) of patients undergoing DFR underwent amputation to treat recurrent infection.

CONCLUSION

Megaprosthetic DFR as part of a two-stage exchange for PJI is a salvage treatment that has a high risk for reinfection compared to non-megaprosthetic TKA. Patients must therefore be counseled accordingly.

LEVEL OF EVIDENCE

Retrospective observational study, Level IV.

Repeat two-stage revision for knee prosthetic joint infection results in very high failure rates

INTRODUCTION

Two stage revision total knee arthroplasty (TKA) is the gold standard for treatment and eradication of knee prosthetic joint infections (PJI), but the literature is limited on the outcomes of repeat two-stage TKA after PJI recurrence. This study presents the outcomes of repeat two-stage revision TKA and investigates potential factors contributing to success or failure, aiming to assist counselling and decision-making.

METHODS

A retrospective study was undertaken investigating all two-stage revision TKA performed at one institution between 2005 and 2020. Twenty cases underwent repeat two-stage revision TKA. Patient outcomes and factors contributing to treatment success or failure were investigated. PJI was diagnosed according to MSIS criteria.

RESULTS

Of the 20 cases, 14 were classified as failed treatment (70%) due to a failure to eradicate infection, further surgical intervention or death. In this cohort, there were no statistically significant differences between the groups regarding factors contributing to treatment success or failure. In the success group, patient reported functional outcomes were variable.

CONCLUSION

This study demonstrates that patients undergoing a repeat two-stage TKA have very poor outcomes. This study did not identify any factors that predicted failure. Patients need to be counselled regarding poor outcomes with repeat two-stage TKA, and other treatment options such as early amputation or lifelong suppression should be considered.

Deleterious Musculoskeletal Conditions Secondary to Lower Limb Loss: Considerations for Prosthesis-Related Factors

Significance: The intent of this work was to summarize the existing evidence of, and highlight knowledge gaps specific to, prosthetic devices/componentry and training regimes, particularly in the context of the human-device interaction and deleterious musculoskeletal conditions secondary to lower limb loss. Recent Advances: With the recent and evolving technological advancements in prostheses, there are numerous devices available to individuals with lower limb loss. Current literature demonstrates the importance of expanding the knowledge of all prosthetic device-specific factors and the significance of proper prescription, fit, and alignment, along with adequate device-/activity-specific training, to enhance human-device interaction, reduce gait abnormalities and compensatory motions, and as a result, mitigate risk for secondary musculoskeletal conditions. Critical Issues: Inadequate device prescription, fit, alignment, and training are evident owing to the lack of knowledge or awareness of the many device-specific properties and factors, leading to suboptimal use, as well as, biomechanical compensations, which collectively and adversely affect the function, activity level, and overall health of the prosthesis user. Future Directions: To maximize optimal outcomes after lower limb loss, it is essential to better appreciate the factors that affect both prosthesis use and satisfaction, particularly any modifiable factors that might be targeted in rehabilitation interventions such as device prescription, fit/alignment, and training regimes. A better understanding of such device-specific factors will help enhance the human-device interaction and resulting functional performance, thereby reducing secondary musculoskeletal conditions, allowing for the readiness of the fighting force (return-to-duty/redeployment) and/or improved reintegration into civilian society/work, and overall enhancing quality of life after lower limb loss.

Current Insights in the Evaluation and Treatment of Infected Total Knee Arthroplasty

Total knee arthroplasty is a widely successful procedure, but a small percentage of patients have a postoperative course complicated by periprosthetic joint infection (PJI). PJI is a difficult problem to diagnose and to treat, and the management of PJI differs, depending on the acuity of the infection. This paper discusses the established and newer technologies developed for the diagnosis of PJI as well as different treatment considerations and surgical solutions currently available.

Fusion rate of 89% after knee arthrodesis using an intramedullary nail: a mono-centric retrospective review of 48 cases

PURPOSE

Knee arthrodesis is an established procedure for limb salvage in cases of recurrent infection, total knee arthroplasty soft tissue defect, poor bone stock or a deficient extensor mechanism. Surgical options include compression plate, external fixator and arthrodesis nail. Different types of nail exist: long fusion nail, short modular nail and bridging nail. This study presents the results on knee arthrodesis using different types of intramedullary nails. The aim is to assess if a specific type of nail has a better fusion rate, clinical outcome and lower complication rate.

METHODS

A mono-centric retrospective study of 48 knees arthrodesis was performed between 2000 and 2018. 15 T2^™ Arthrodesis Nail, 6 OsteoBridge^® Knee Arthrodesis and 27 Wichita^® fusion nail were used. The mean clinic and radiological follow-up was 9.8 ± 3.8 years (2.6-18 years).

RESULTS

Fusion rate was 89.6%. Time to fusion was 6.9 months. Mean Parker score was 6.9/9 points. Visual Analogic Scale was 1.9. The Wichita^® fusion nail showed better results in terms of fusion, time to fusion and clinical outcome measured by Parker score and VAS but without statistical significance. The early revision rate was 10.4% and 20.8% presented a late complication requiring a surgery, due to nonunion or infection. 93.3% of infection was cured. Two patients live with a fistula (4.2%) and 1 was amputated (2.1%).

CONCLUSION

Although burdened by a big complication rate, knee arthrodesis with an intramedullary nail provides satisfactory results and is a good alternative to above-knee-amputation. The Wichita^® fusion nail shows a tendency to better results compared to the two other nails.

LEVEL OF EVIDENCE

Case series, level IV.

Modular knee arthrodesis secures limb, mobility, improves quality of life, and leads to high infection control in periprosthetic knee infection, when revision knee arthroplasty is not an option

INTRODUCTION

This study compared the outcome of knee arthrodesis versus hinged total knee arthroplasty (TKA) in patients suffering from periprosthetic joint infection (PJI).

METHODS

104 patients with PJI were treated using a two-stage exchange of failed TKA. In case of non reconstructable bone loss or loss of extension mechanism, a modular intramedullary arthrodesis nail was used for reimplantation [Knee Arthrodesis Module (KAM); n = 52]. The control group was retrospectively matched treated using a hinged revision TKA [Rotating Hinge Knee (RHK); n = 52]. PJI remission rates, functional outcome (WOMAC; KSS) and quality of life (SF-12), as well as comorbidities and pain were evaluated.

RESULTS

Mean age was 72.5 years. Charlson Comorbidity Index was higher in the KAM group (3.3 vs. 2.8). PJI remission rate was 89.4% (88.5% vs. 90.4%, respectively). In case of reinfection, implant retention was mostly possible in the RHK group (7.7%), whereas amputations were mostly performed in the KAM group (9.6%). Significant pain reduction (VAS 7.9-2.8) was achieved in both groups. Walking distance was significantly reduced in the KAM groups versus the RHK group (504 vs. 1064 m). WOMAC and KSS function scores were significantly reduced in the KAM group (25 vs. 40 and 35 vs. 64). Only moderate reduction in quality of life in the KAM group was observed (SF-12 physical: 34 vs. 40; SF-12 mental: 51 vs. 56) respectively.

CONCLUSIONS

Arthrodesis using a modular intramedullary nail is an alternative for limb salvage, pain reduction, and preservation of quality of life and everyday mobility, when revision TKA is not an option. This study presents the largest number of case, comparing the outcome after performing an arthrodesis versus hinged TKA after septic failed TKA.

Above-the-knee amputation versus knee arthrodesis for revision of infected total knee arthroplasty: Recurrent infection rates and functional outcomes of 43 patients at a mean follow-up of 6.7 years

INTRODUCTION

In cases of repeated treatment failure of periprosthetic joint infections (PJI) of the knee, above-the-knee amputation (AKA) or knee arthrodesis can be proposed to reduce the risk of recurrent infection, especially in cases with major bone defects or irreparable damage to the extensor mechanism of the knee. Since AKA versus knee arthrodesis results have been rarely assessed for these indications, we conducted a retrospective case-control study to compare both the rates of recurrent infection and functional outcomes. Hypothesis Patients who underwent AKA had fewer recurrent infections than those who had arthrodesis.

MATERIALS AND METHODS

Twenty patients who underwent AKA and 23 patients who had knee arthrodesis, between 2003 and 2019, were retrospectively included in this study. These two groups were comparable in age (73.8 versus 77.7 years (p=.31)) and sex (10 women and 10 men versus 16 women and seven men (p=.19)). Each group was analyzed individually and then compared in terms of survival (recurrent infection) and functional outcomes using clinical assessment scores (visual analog scale (VAS), French neuropathic pain questionnaire (DN4), Parker and Palmer mobility score and the 36-item short-form survey (SF-36)).

RESULTS

The rate of recurrent infection was 10% (two out of 20 patients) for the AKA group and 21.75% (five out of 23 patients) for the arthrodesis group (p=.69). The mean follow-up for the AKA group was 4.18 years (1.2-11.8) and 9.7 years (1.1-14.33) for the arthrodesis group (p=.002). The number of previous revisions (three (1.5-4) for AKA and two (2-3) for arthrodesis) and the time between the primary arthroplasty and surgical procedure were significantly greater in the AKA group (48.0 (12.0-102.0) months) than the arthrodesis group (48.0 (24.0-87.0) months) (p<001). The AKA group had significantly better clinical results for VAS (2.7±2.2 vs. 3.1±3.3), DN4 (1.5±2.1 vs. 2.6±2.9), Parker and Palmer (5.2±1.7 vs. 4.6±1.4), and SF-36 (30.9±15.6 vs. 26.9±17.0) (p<001).

CONCLUSION

Above-the-knee amputation and knee arthrodesis showed no differences in the rate of recurrent sepsis. However, the comparison of the two groups demonstrated that patients who underwent an AKA had less pain, were more autonomous and had a better quality of life.

LEVEL OF EVIDENCE

III; retrospective case-control.

Medicare Physician Fee Reimbursement for Revision Total Knee Arthroplasty Has Not Kept Up with Inflation from 2002 to 2019

BACKGROUND

As orthopaedic physician fees continue to come under scrutiny by the U.S. Centers for Medicare & Medicaid Services (CMS), there is a continued need to evaluate trends in reimbursement rates across contemporary time intervals. Although substantially lower work relative value units (RVUs) have been previously demonstrated for septic revision total knee arthroplasty (TKA) compared with aseptic revisions, to our knowledge, there has been no corresponding analysis comparing total physician fees. Therefore, the purpose of our study was to analyze temporal trends in Medicare physician fees for septic and aseptic revision TKAs.

METHODS

Current Procedural Terminology (CPT) codes related to septic 1-stage and 2-stage revision TKAs and aseptic revision TKAs were categorized. From 2002 to 2019, the facility rates of physician fees associated with each CPT code were obtained from the CMS Physician Fee Schedule Look-Up Tool. Monetary data from Medicare Administrative Contractors at 85 locations were used to calculate nationally representative means. All total physician fee values were adjusted for inflation and were translated to 2019 U.S. dollars using Consumer Price Index data from the U.S. Bureau of Labor Statistics. Cumulative annual percentage changes and compound annual growth rates (CAGRs) were computed utilizing adjusted physician fee data.

RESULTS

After adjusting for inflation, the total mean Medicare reimbursement (and standard deviation) for aseptic revision TKA decreased 24.83% ± 3.65% for 2-component revision and 24.21% ± 3.68% for 1-component revision. The mean septic revision TKA total Medicare reimbursement declined 23.29% ± 3.73% for explantation and 33.47% ± 3.24% for reimplantation. Both the dollar amount (p < 0.0001) and the percentage (p < 0.0001) of the total Medicare reimbursement decline for septic revision TKA were significantly greater than the decline for aseptic revision TKA.

CONCLUSIONS

Septic revision TKAs have been devalued at a rate greater than their aseptic counterparts over the past 2 decades. Coupled with our findings, the increased resource utilization of septic revision TKAs may result in financial barriers for physicians and subsequently may reduce access to care for patients with periprosthetic joint infections.

CLINICAL RELEVANCE

The devaluation of revision TKAs may result in reduced patient access to infection management at facilities unable to bear the financial burden of these procedures.

Low complication rate and better results for intramedullary nail - arthrodesis for infected knee joints compared to external fixator-a series of one hundred fifty two patients

PURPOSE

Arthrodesis of the knee joint is still a salvage procedure after recurrent prosthetic joint infections (PJI) of total knee arthroplasties (TKA) with substantial bone loss and seems to be a good solution to avoid amputation. Until now, intramedullary arthrodesis has increasingly been performed; no study has yet been published to compare these techniques after septic removal of TKA in terms of functional assessment and quality of daily life.

METHODS

In a single-centre retrospective setting, clinical and radiographic evaluation of consecutive patients after knee arthrodesis using intramedullary and external fixation for infected knee joints was performed. All patients were evaluated clinically, with x-ray and questionnaire including analysis regarding any complications at latest follow-up of a minimum 12 months postoperatively.

RESULTS

We included 152 patients (75 females, 77 males) in this study. The mean age of the patients at surgery was 63.6 years (range 12 to 90 years). The minimum follow-up was 12 months (mean 3.1 years, range 12 to 49 months). Arthrodesis with external fixator (83 patients, 52.2%) showed less blood loss and less peri-operative complications (1.6%) but a high rate of post-operative, pin-track infections (35.5%); loose pins (12.7%); and pin fractures (4.8%), and therefore risk factors for instability and nonunion (30.9%). Revision rate was 22.6% for arthrodesis with external fixator, and the primary union rate was 65.6%. Intramedullary arthrodesis (69 patients, 43.4%) showed a similar re-infection rate to external fixation (16.1% and 15.9%, respectively) but a significantly lower revision rate (5.4%, p < 0.001). Eighty percent of patients with intramedullary arthrodesis showed very good patient-related outcomes regarding pain, function and daily life activities in the questionnaire.

CONCLUSION

Despite similar results regarding patient satisfaction and everyday competences in questionnaires, intramedullary arthrodesis of the knee is superior to the external fixator, as it results in fewer complications, lower revision rate, and union rates/loosening.

Motor cortex transcranial direct current stimulation effects on knee osteoarthritis pain in elderly subjects with dysfunctional descending pain inhibitory system: A randomized controlled trial

BACKGROUND

Although evidence has indicated a positive effect of transcranial direct current stimulation (tDCS) on reducing pain, few studies have focused on the elderly population with knee osteoarthritis (KOA).

OBJECTIVE

To evaluate whether tDCS reduces KOA pain in elderly individuals with a dysfunctional descending pain inhibitory system (DPIS).

METHODS

In a double-blind trial, individuals ≥ 60 years with KOA pain and a dysfunctional DPIS, we randomly assigned patients to receive 15 daily sessions of 2 mA tDCS over the primary motor cortex (anode) and contralateral supraorbital area (cathode) (M1-SO) for 20 min or sham tDCS. Change in pain perception indexed by the Brief Pain Inventory (BPI) at the end of intervention was the primary outcome. Secondary outcomes included: disability, quantitative sensory testing, pain pressure threshold and conditioned pain modulation (CPM). Subjects were followed-up for 2 months.

RESULTS

Of the 104 enrolled subjects, with mean (SD) age of 73.9 (8.01) years and 88 (84.6%) female, 102 finished the trial. In the intention-to-treat analysis, the active tDCS group had a significantly greater reduction in BPI compared to the sham group (difference, 1.59; 95% CI, 0.95 to 2.23; P < 0.001; Cohen's d, 0.58); and, also a significantly greater improvement in CPM-pressure in the knee (P = 0.01) and CPM-pain in the hand (P = 0.01). These effects were not sustained at follow-up. The intervention was well tolerated, with no severe adverse effects.

CONCLUSION

M1-SO tDCS is associated with a moderate effect size in reducing pain in elderly patients with KOA after 15 daily sessions of stimulation. This intervention has also shown to modulate the DPIS.

Management of Periprosthetic Joint Infection and Extensor Mechanism Disruption With Modular Knee Fusion: Clinical and Biomechanical Outcomes

Background

Extensor mechanism disruption (EMD) combined with periprosthetic joint infection (PJI) after total knee arthroplasty are life-changing complications. The literature suggests many eventually receive above-knee amputation and lose ambulatory function. An alternative is modular knee fusion (KF), but little is known about its outcomes and biomechanical function. We report early term results on a case series of patients.

Methods

A retrospective review was conducted of patients who underwent 2-stage reconstruction with modular KF for combined EMD and PJI. Patient-reported outcomes at 1 year after arthrodesis and complications of surgery were recorded. Biomechanical analysis was conducted on 6 patients >1 year after surgery to measure gait speed and balance.

Results

Fifteen patients received a modular KF. At the most recent follow-up visit (average 25.7 months), 12 patients had their modular KFs in place and were ambulatory while 2 had died. Six patients used a walker; 4, a cane; and 2, unassisted. Gait analysis of 6 of these patients showed variation in patterns and speed. Balance was better than historical controls treated with above-knee amputation. Average Knee Injury and Osteoarthritis Outcome Score Junior was 76 ± 11.

Conclusion

Modular KF for EMD and PJI can result in successful outcomes in terms of preventing additional operations and maintaining ambulation. While speed is variable, physical testing shows this method for limb salvage may allow patients to ambulate with a gait aid although further studies are needed to evaluate midterm and long-term results.

Long-Term Patient-Related Quality of Life after Knee Periprosthetic Joint Infection

BACKGROUND

We aimed to evaluate the impact of knee periprosthetic joint infection (PJI) by assessing the patients' long-term quality of life and explicitly their psychological wellbeing after successful treatment.

METHODS

Thirty-six patients with achieved eradication of infection after knee PJI were included. Quality of life was evaluated with the EQ-5D and SF-36 outcome instruments as well as with an ICD-10 based symptom rating (ISR) and compared to normative data.

RESULTS

At a follow-up of 4.9 ± 3.5 years the mean SF-36 score was 24.82 ± 10.0 regarding the physical health component and 46.16 ± 13.3 regarding the mental health component compared to German normative values of 48.36 ± 9.4 (p < 0.001) and 50.87 ± 8.8 (p = 0.003). The mean EQ-5D index reached 0.55 ± 0.33 with an EQ-5D VAS rating of 52.14 ± 19.9 compared to reference scores of 0.891 (p < 0.001) and 68.6 ± 1.1 (p < 0.001). Mean scores of the ISR revealed the psychological symptom burden on the depression scale.

CONCLUSION

PJI patients still suffer from significantly lower quality of life compared to normative data, even years after surgically successful treatment. Future clinical studies should focus on patient-related outcome measures. Newly emerging treatment strategies, prevention methods, and interdisciplinary approaches should be implemented to improve the quality of life of PJI patients.

Irrigation and Debridement with Chronic Antibiotic Suppression Is as Effective as 2-Stage Exchange in Revision Total Knee Arthroplasty with Extensive Instrumentation

BACKGROUND

Extraction of implants because of periprosthetic infection (PJI) following complex revision total knee arthroplasty (rTKA) with extensive instrumentation is a daunting undertaking for surgeon and patient alike. The purpose of the present study was to evaluate whether infections following complex rTKA are better treated with 2-stage exchange or irrigation and debridement (I&D) with modular component exchange and antibiotic suppression in terms of infection control, reoperation, and function.

METHODS

We reviewed rTKAs that had been performed for the treatment of PJI from 2005 to 2016. Extensive instrumentation was defined as the presence ≥1 of the following: metaphyseal cones/sleeves, distal femoral replacement, periprosthetic fracture instrumentation, or fully cemented stems measuring >75 mm. Cases were categorized according to the initial treatment (I&D with antibiotic suppression or initiation of 2-stage exchange).

RESULTS

Eighty-seven patients with PJI and extensive instrumentation were identified: 56 patients who were managed with I&D with suppression and 31 who were managed with the initiation of 2-stage exchange. The rate of success (defined as no reoperation for infection) was similar for the 2 groups (62.5% the I&D group compared with 67.7% for the 2-stage group; p = 0.62). The rate of mortality was also similar (39.3% for the I&D group compared with 38.7% for the 2-stage group; p = 0.96). Of the 31 patients in the 2-stage group, 18 (58.1%) underwent reimplantation with a revision replacement. Of those 18 patients, 13 were still infection-free at the time of the most recent follow-up; however, when the analysis was expanded to all 31 patients in the 2-stage group, only 13 (41.9%) both had a successful reimplantation and did not require additional surgery for infection. Nine (29.0%) of the 31 patients in the 2-stage group never underwent the second stage, and 4 (12.9%) of the 31 required arthrodesis at the second stage. In contrast, 35 (62.5%) of the 56 patients in the I&D group were successfully managed, without additional surgery for the treatment of infection. At the time of the latest follow-up (mean, 3.2 years; range, 2 to 13 years), more patients in the I&D group were ambulatory (76.8% in the I&D group compared with 54.8% in the 2-stage group; p = 0.05) and maintained a functional bending knee joint (85.7% in the I&D group compared with 45.2% in the 2-stage group; p < 0.001).

CONCLUSIONS

In the treatment of periprosthetic infection of rTKA with extensive instrumentation, I&D with chronic antibiotic suppression was as effective as 2-stage exchange in terms of preventing reoperation for infection and was more effective in terms of maintaining function. These data apply to rTKA with extensive periarticular instrumentation and should not be extrapolated to primary or simple revision implants.

LEVEL OF EVIDENCE

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

Risk factors of pain, physical function, and health-related quality of life in elderly people with knee osteoarthritis: A cross-sectional study

Data on the precise mechanisms of the complex interactions of factors related to clinical impact of knee osteoarthritis (KOA) in the elderly population remain limited. To find predictors that explain pain intensity, physical function, and quality of life in elderly KOA subjects, we performed a cross-sectional analysis of the baseline data from a randomized trial. The trial included 104 subjects (aged ≥60) with KOA pain and dysfunctional endogenous pain-inhibitory system activity assessed by conditioned pain modulation (CPM). Three multiple linear regression models were performed to understand the independent predictors of Brief Pain Inventory (BPI), WOMAC function subscale (WOMACFunc), and SF-12 physical subscale (SF12-PCS). Model 1 showed that BPI pain score was predicted by low CPM response, high von-Frey light touch threshold, worse radiological severity as indexed by Kellgren-Lawrence grade (KL), high von-Frey punctate pain intensity and high levels of anxiety (adjusted R2 = 27.1%, F (6,95) = 7.27, P < 0.0001). In model 2, von-Frey light touch threshold, KL, depressive symptoms indexed by Beck Depression Inventory (BDI), level of sleepiness and pain pressure threshold were risk factors for SF12-PCS (adjusted R2 = 31.9%, F (5,96) = 10.5, P < 0.0001). Finally, model 3 showed that WOMACFunc was predicted by BDI, KL and BPI (adjusted R2 = 41%, F (3,98) = 24.42, P < 0.0001). Our data provides an interesting framework to understand the predictors of KOA pain in the elderly and highlights how its related outcomes are affected by disease-specific factors, somatosensory dysfunction and emotional factors.

Gastrocnemius Muscle Flaps for Soft Tissue Coverage in Periprosthetic Knee Joint Infection

BACKGROUND

Soft tissue deficiency in total knee arthroplasty infection is a potentially devastating complication. Gastrocnemius muscle flaps can be used to address this problem. We aim at reporting survival rates of these reconstructions and identify risk factors for failure.

METHODS

A retrospective evaluation of all flaps performed at a single center between 2006 and 2019 was performed. Clinical and microbiological results were assessed in 43 cases after a median follow-up period of 53 months (25%-75% interquartile range 18-79). Function was assessed using the Oxford Knee Score. We analyzed the infection-free survival and identified risk factors using survival comparison and (non-)parametric testing.

RESULTS

Infection-free survival was 71% at 2 years and 63% at 5 years. The rate of subsequent amputation was 16% with a mortality rate of 26% during follow-up. Four patients did not undergo reimplantation and 11 patients received an arthrodesis implant. There were no failures of the flap itself. The Charlson Comorbidity index was the only relevant risk factor for reinfection. Coagulase-negative staphylococci were most common organisms identified. Postoperative function was limited with a mean Oxford Knee Score of 20.

CONCLUSION

Gastrocnemius flap coverage is a valid option for soft tissue reconstruction in periprosthetic infections to retain a functioning limb despite a high complication rate and the risk of subsequent amputation.

Knee Arthrodesis Is a Durable Option for the Salvage of Infected Total Knee Arthroplasty

BACKGROUND

Knee arthrodesis (KA) and above-knee amputation (AKA) have been used for salvage of failed total knee arthroplasty (TKA) after periprosthetic joint infection (PJI). However, few studies have assessed the outcomes of KA after TKA PJI, as it remains an uncommon procedure. We investigated rates of AKA, control of infection, and ambulatory status after KA for TKA PJI treatment.

METHODS

This was a retrospective and single-surgeon series of 51 failed TKAs due to PJI treated with two-stage KA between 2000 and 2016 with a minimum of 2-year follow-up. Patient demographics, comorbidities, surgical history, radiographic data, and outcomes of KA treatment were recorded.

RESULTS

Infection was successfully controlled in 48 of 51 patients (94.1%); of these, 24 knees (50.0%) required no reoperation subsequent to the index KA, whereas the remaining 24 (50.0%) patients required a median of 1 additional operation. Nonunion, malunion, or delayed union was noted in 10 patients (19.6%). Of the 48 patients who were successfully treated with KA, 41 patients (85.4%) remained ambulatory after KA and 9 of these patients (18.8%) did not require assistive devices. Three of 51 patients (5.9%) progressed to AKA after KA.

CONCLUSION

Patients undergoing KA for TKA PJI had high rates of infection control and preservation of ambulatory status, with low rates of progression to AKA in our study.

LEVEL OF EVIDENCE

Level IV-case series.

The Dark Side of Arthroplasty: Competing Risk Analysis of Failed Hip and Knee Arthroplasty With Periprosthetic Joint Infection

BACKGROUND

Increasing total hip (THA) and knee (TKA) arthroplasties inevitably lead to accumulating failed arthroplasty (FA) with periprosthetic joint infections (PJI) and definite treatment recommendations are scarce. Our aims were to evaluate patient and infection site specific risk factors, and to identify case-dependent salvage procedure recommendations.

METHODS

Retrospective analysis was conducted of salvage procedures for FA after PJI (amputation, Girdlestone resection arthroplasty [GRA], arthrodesis, or chronic fistulation [CF]) from 2008 to 2018. Univariable and multivariable modeling of revision and mortality rates, using cumulative incidence competing risk analysis, and Cox proportional hazards models were calculated.

RESULTS

In total, 135 patients (THA 62%; TKA 38%) were diagnosed for FA after PJI, having undergone an average of 3 [1-4] revisions at a mean follow-up of 12.8 [7.8-20.9] years. Forty-four percent of THAs and 55% of TKAs had to be revised following FA, 44% deceased during follow-up, and 16% could be reconverted to an infection-free arthroplasty. GRA revealed significantly higher revision rates than CF (P = .015) for THA. Lower age (P = .003), higher number of revisions before FA (P = .007), more than one microorganism at infection site (P = .034), and GRA (P = .037, only THA) prevailed independent risk factors for revision. Patients' age remained an independent mortality risk factor (P = .001).

CONCLUSION

High-risk patients suffering from FA after THA with poor constitution profit from controlled constitution of CF, reducing the risk for revision surgeries and hospitalization. In case of FA after TKA, data did not allow definite treatment recommendations. We believe that education concerning amputation should be considered early after multiple TKA revisions.

High Rate of Fusion but High Complication Rate After Knee Arthrodesis for Infected Revision Total Knee Replacement

BACKGROUND

Knee arthrodesis is a demanding technique regarding difficulties to achieve bone fusion, control of infection and its associated complications. The purpose of this study was to evaluate if knee arthrodesis should still be indicated after failed revision total knee replacement.

METHODS

This was a retrospective study of 45 patients. Age, gender, follow-up, pathogens, Charlson comorbidity index, time from primary arthroplasty to arthrodesis, number of previous procedures, surgical technique, functional capability assessed by the SF-12 score, limb-length discrepancy after arthrodesis, presence of radiographic knee fusion, and complications were recorded.

RESULTS

The mean age at the time of operation was 72 years. 29% of patients were men, 71% were women, and the mean follow-up was 8.5 years. The average Charlson comorbidity index was 4.5. The most common microorganisms isolated were Staphylococcus epidermidis (29%), Staphylococcus aureus (22%), and Pseudomonas aeruginosa (15%). In 20% of patients, no microorganism was identified, and in 37% of patients the infection was polymicrobial. Time from primary total knee arthroplasty to arthrodesis was 55 months, and patients underwent a mean of 3.9 previous surgeries. The surgical technique used was an intramedullary long nail in 95.5%. Functionally, 93.3% of patients walked with weight bearing. The SF-12 was higher after arthrodesis (p < 0.05). Mean limb length discrepancy was 2.4 cm. Among the group treated with long intramedullary nailing, 91.1% obtained tibiofemoral fusion. Complications occurred in 37.6% of patients.

CONCLUSIONS

Knee arthrodesis with a long intramedullary nail after failed infected revision total knee replacement has a high rate of fusion, but the complication rate is high.

Patient-reported outcomes after above-knee amputation for prosthetic joint infection

BACKGROUND

Prosthetic joint infection (PJI) is a challenging complication after total knee arthroplasty (TKA). Above-knee amputation (AKA) is a salvage procedure that may be performed after revision TKAs fail to eradicate PJI. Few studies have investigated patient-reported outcomes. This study investigates patient-reported functional outcomes and overall satisfaction in a cohort of patients who underwent AKA for PJI.

METHODS

We performed a retrospective study of all patients who underwent AKA for PJI from 2002 to 2015 at a tertiary academic institution in the rural northeastern United States, along with prospective phone interviews. Functional outcomes and overall satisfaction were adapted from the Above-The-Knee Amputation Functional Ability Questionnaire. Additional variables included age, sex, American Society of Anesthesiologists (ASA) Score, and mortality.

RESULTS

Forty-four patients were included in the study. Eighteen patients died prior to study initiation, with a mean time of 948 days (2.6 years) between AKA and death. The 5-year mortality rate was 50%. Among the 14 patients who completed the survey, 12 (86%) were fit for prosthesis following AKA. Of these, 10 (71%) required the use of an assistive device and one (seven percent) reported being functionally independent with their prosthesis. Five (36%) required further surgery after their AKA. Twelve (86%) stated that they were satisfied with their AKA and 5 (42%) would have done it sooner if offered.

CONCLUSIONS

Patients who underwent AKA for PJI reported a low level of independence and ability to ambulate with a high mortality rate. However, most were satisfied with their AKA and would choose it again.

Two-Stage Arthrodesis after an Infected Total Knee Replacement Using a Coupled Nail and Dual-Plate Construct: A Third-World Solution and Review of Options

Infection following total knee arthroplasty is a serious and increasingly common complication. Several treatment options are available. Although a two-stage revision remains the gold standard, salvage procedures are sometimes needed. We describe a case of an infected knee arthroplasty that was salvaged using a novel technique combining two linked intramedullary nails and bilateral compression plating.

Work Relative Value Units Do Not Adequately Support the Burden of Infection Management in Revision Knee Arthroplasty

BACKGROUND

Revision total knee arthroplasty for infection is challenging. Septic revisions, whether 1-stage or 2-stage, may require more time and effort than comparable aseptic revisions. However, the burden of infection may not be reflected by the relative value units (RVUs) assigned to septic revision compared with aseptic revision. The purposes of this study were to compare the RVUs of aseptic and septic revision total knee arthroplasties and to calculate the RVU per minute for work effort.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was analyzed for the years 2006 to 2017. The Current Procedural Terminology (CPT) code 27487 and the International Classification of Diseases, Ninth Revision (ICD-9) code 996.XX, excluding 996.6X, were used to identify all aseptic revision total knee arthroplasties (n = 12,907). The CPT code 27487 and the ICD-9 code 996.6X were used to determine all 1-stage septic revision total knee arthroplasties (n = 891). The CPT codes 27488 and 11981 were used to identify the first stage of a 2-stage revision (n = 293). The CPT codes 27447 and 11982 were used to identify the second stage of a 2-stage revision (n = 279). After 4:1 propensity score matching, 274 cases were identified per septic cohort (aseptic single-stage: n = 1,096). The RVU-to-dollar conversion factor was provided by the U.S. Centers for Medicare & Medicaid Services (CMS), and RVU dollar valuations were calculated.

RESULTS

The septic second-stage revision was used as the control group for comparisons. The RVU per minute for the aseptic 2-component revision was 0.215, from a mean operative time of 148.95 minutes. The RVU per minute for the septic, 2-component, 1-stage revision was 0.199, from a mean operative time of 160.6 minutes. For septic, 2-stage revisions, the first-stage RVU per minute was 0.157, from a mean operative time of 138.1 minutes. The second-stage RVU per minute was 0.144, from a mean operative time of 170.0 minutes. Two-component aseptic revision total knee arthroplasty was valued the highest.

CONCLUSIONS

Despite the increased complexity and worse postoperative outcomes associated with revision total knee arthroplasties for infection, the current physician reimbursement does not account for these challenges. This inadequate compensation may discourage providers from performing these operations and, in turn, make it more difficult for patients with periprosthetic joint infection to receive the necessary treatment. Therefore, the CPT code revaluation may be warranted for these procedures.

[Modular arthrodesis system TITAN (KAM-TITAN) after failed revision total knee arthroplasty : Operative technique and clinical experience]

OBJECTIVE

Restoration of a painless, weight-bearing extremity with a modular knee arthrodesis system based on a cementless modular revision stem for rotationally stable, diaphyseal anchorage.

INDICATIONS

Severe bone loss and compromised soft tissue after failed total knee arthroplasty, two-stage revisions and non-reconstructible knee extensor mechanism deficiency.

CONTRAINDICATIONS

Extensive osteolysis preventing diaphyseal anchorage of the prosthesis. Contralateral arthrodesis of the knee joint and/or ipsilateral arthrodesis of the hip joint and contralateral lower extremity amputation.

SURGICAL TECHNIQUE

In revision cases, removal of the total knee arthroplasty, spacer, the bone cement and all intramedullary granulation tissue. Reaming the medullary cavity with intramedullary reamers to cortical contact. Restoring leg length and rotation with trial implants. After implantation of the femoral and tibial stems, placing and tensioning of the rotationally aligned coupling elements.

POSTOPERATIVE MANAGEMENT

Mobilization on two forearm crutches from postoperative day 1. Removal of the Redon drains after 48 h. Partial weight bearing of 20 kg for 6 weeks postoperatively. If plain radiographs show unchanged seating of the prosthesis after 6 weeks, loading can be increased by 10 kg per week until full weight bearing is achieved.

RESULTS

Between 2007 and 2012 clinical data were collected and analyzed retrospectively. A total of 27 patients had been treated within a two-stage exchange procedure with implantation of a modular intramedullary arthodesis nail TITAN (KAM-TITAN). The mean follow-up was 30.9 ± 12.0 months. A functional evaluation was performed using the Oxford Knee Score (OKS). The analyzed patients showed a mean score of 39.2 ± 8.3. To determine the pain level the Visual Analog Scale (VAS) for pain was used and showed a mean score of 2.9 ± 1.3. The rate of definitely free of infection (using Laffer criteria) at last follow-up was 85.2%.

Transfemoral amputation following total knee arthroplasty

Aims

The aim of this study was to characterize the factors leading to transfemoral amputation after total knee arthroplasty (TKA), as well as the rates of mortality and functional independence after this procedure in these patients.

Patients and Methods

This was a multicentre retrospective review with a prospective telephone survey for the assessment of function. All patients with a TKA who subsequently required transfemoral amputation between January 2001 and December 2015 were included. Demographic information, medical comorbidities, and postoperative mortality data were collected. A 19-item survey was used for the assessment of function in surviving patients.

Results

A total of 111 patients were included. Their mean age was 61.0 years (42.0 to 88.0) at the time of TKA, with a subsequent mean of 3.7 operations (0 to 15) over a mean period of 6.1 years (0.05 to 30.1) before amputation. The indication for amputation was chronic infection in 97 patients (87.4%). The rate of five-year survival was 51.7%, and advanced age (p = 0.001) and renal failure (p = 0.045) were associated with an increased risk of mortality. Of the 62 surviving patients, 34 completed the survey; 32 (94.1%) owned a prosthesis but only 19 (55.9%) used it; 19 (55.9%) primarily used a wheelchair for mobility; 27 (79.5%) had phantom pain; and 16 (47.1%) required chronic pain medication. Only 18 patients (52.9%) were satisfied with the quality of life.

Conclusion

Patients with complications after TKA, in whom transfemoral amputation is considered, should be made aware of the high rate of mortality and the poor functional outcome in the survivors. Alternative forms of treatment including arthrodesis of the knee should be investigated.