Aseptic versus septic revision total knee arthroplasty: patient satisfaction, outcome and quality of life improvement

Etiology and prosthesis model have no influence in the functional outcomes of total knee arthroplasty revision surgery at five years

Background

The rising number of total knee arthroplasty (TKA) replacements and their uncertain functional results according to the revision etiology and the prosthesis model implanted are a challenge for orthopedic surgeons and patients. A better knowledge of these results is mandatory to make the best decision. We present our clinical outcomes with a 5-year follow-up.

Methods

We retrospectively reviewed 104 patients, 108 knees (77 aseptic and 31 septic), who underwent TKA revision surgery from 2007 to 2017 with three different models of prosthesis. KSS score, range of motion (ROM), pain, and independence for walking were recorded at 5 years according to our own database and the clinical interview and compared to the different models of prosthesis and the etiology of the revision.

Results

The results showed 81.5 % of good or excellent functional outcomes in our patients with a mean KSS score of 76,7 ± 14,3, a mean ROM of 1.68 ± 0.30 radians, and 77 % of them are independent for walking without any aids. The results do not show any difference between the groups comparing the model of prosthesis and the etiology of the revision surgery.

Conclusions

At 5 years, TKA revision surgery offers good clinical and functional outcomes, independence for walking, good range of motion, and low residual pain regardless of the cause of the revision or the model of prosthesis.

Maintenance of the joint line and posterior condylar offset are the most notable variables for successful outcomes of revision total knee arthroplasty

INTRODUCTION

Controversy regarding which variables should be prioritized for better outcomes in revision total knee arthroplasty (RTKA) exists. This study aimed to comprehensively analyze the variables affecting RTKA outcomes.

MATERIALS AND METHODS

We retrospectively identified 87 RTKAs in 82 patients who were performed between March 2014 and February 2020. Range of motion (ROM), including flexion contracture (FC) and further flexion (FF), was analyzed according to the covariates. The covariates included mode of failure, joint line position, anteroposterior (AP) position, rotational alignment of the femoral component, and patellofemoral alignment. The differences between the final follow-up values of each RTKA variable and those of the native knee were evaluated. The clinical outcomes were evaluated.

RESULTS

No significant differences were observed between the joint line positions of the RTKA and native knees. The patellar and AP positions of the femoral component were restored to pre-TKA values. The femoral component had an external rotation of 2.78° compared with the native knee. In multivariable stepwise regression analysis, restoration of the adductor tubercle joint line and posterior condylar offset (PCO) were significant variables affecting ROM. Septic RTKA (33 knees) resulted in poor FF outcomes (p = 0.030) and Western Ontario and McMaster Universities Osteoarthritis Index stiffness (WOMAC S) scores (p < 0.001), compared with aseptic RTKA (54 knees).

CONCLUSIONS

Restoration of the joint line position and PCO are crucial factors for improved ROM in RTKA. Joint line elevation in RTKA resulted in worse ROM than joint line lowering. In addition, RTKA due to septic failure had inferior ROM and WOMAC S scores compared with RTKA due to aseptic failure.

LEVEL OF EVIDENCE

Level III, cohort study.

Risk of Infection After Septic and Aseptic Revision Total Knee Arthroplasty: A Systematic Review

BACKGROUND

The causes of primary total knee arthroplasty (TKA) failure can be divided into septic and aseptic etiologies. It is unclear whether the etiology affects the infection rate after revision TKA. This systematic review was conducted to evaluate whether there is a difference in infection rates between septic and aseptic revision TKA. We hypothesized that infection rates would be higher after septic revision TKA.

METHODS

The PubMed and Embase databases and the Cochrane Library were searched to find studies evaluating infection rates following septic and aseptic revision TKA. We included studies that compared the postoperative infection rates of a group that received revision TKA for aseptic failure and a group that received 1- or 2-stage revision TKA for septic failure. Studies on re-revision TKA and on revision surgery after partial knee arthroplasty were excluded, as were studies of debridement, antibiotics, and implant retention (DAIR).

RESULTS

Twelve studies were included in this systematic review. In studies in which 1- or 2-stage revision TKA was performed for septic failure, septic revision TKA had a significantly higher infection rate than aseptic revision TKA (odds ratio [OR], 6.83; 95% confidence interval [CI], 1.54 to 30.33; p = 0.01). Similarly, in studies in which 2-stage revision TKA was performed for septic failure, septic revision TKA had a significantly higher infection rate than aseptic revision TKA (OR, 4.14; 95% CI, 2.33 to 7.36; p < 0.00001). In the comparison of revision TKA for aseptic loosening and septic revision TKA, septic revision TKA had a higher infection rate than aseptic revision TKA (OR, 4.45; 95% CI, 2.28 to 8.70; p < 0.0001).

CONCLUSIONS

Overall, septic revision TKA had a higher infection rate than aseptic revision TKA. Even when 2-stage revision TKA was performed for septic failure, the infection rate was higher after septic revision TKA than after aseptic revision. Surgeons should explain the relatively high infection rates to patients undergoing revision TKA for septic failure of their primary joint replacement.

LEVEL OF EVIDENCE

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

Impact of Comorbidities and Previous Surgery on Mid-Term Results of Revision Total Knee Arthroplasty for Periprosthetic Joint Infection

(1) Background: In the treatment of periprosthetic joint infection (PJI), the individual host status and previous surgical procedures appear to have a relevant influence on success rates and clinical outcome of knee revision surgery. Current data about the predictive value are limited in this subgroup of patients. (2) Methods: Retrospectively, 107 patients (109 knees) undergoing two-stage exchange knee arthroplasty for PJI using a rotating-hinge design with at least two years follow-up. The cumulative incidence (CI) for different endpoints was estimated with death as competing risk. Univariate and multivariate analyses for potential predictive factors were performed. Patient-related outcome measures (PROMs) for clinical outcome were evaluated. (3) Results: At 8 years, the CI of any revision was 29.6%, and of any reoperation was 38.9%. Significant predictors for risk of re-revision were the Charlson Comorbidity Index (CCI) and the number of previous surgical procedures prior to explanation of the infected implant. The functional and clinical outcome demonstrated acceptable results in the present cohort with a high comorbidity level. (4) Conclusions: A compromised host status and multiple previous surgical procedures were identified as negative predictors for re-revision knee surgery in the treatment of PJI. Reinfection remained the major reason for re-revision. Overall mortality was high.

Clinical Outcomes and Infection Rates Following Revision Total Knee Arthroplasty: Aseptic Failure versus Septic Failure

Background

It is controversial whether revision total knee arthroplasty (TKA) due to septic failure shows inferior clinical outcomes compared with TKA due to aseptic failure. Moreover, few studies have compared the infection rates after revision TKA between aseptic and septic failure. We aimed to compare the clinical outcomes and infection rates after aseptic and septic revision TKA.

Methods

Between April 2006 and May 2019, 68 and 26 patients underwent revision TKA due to aseptic failure (aseptic group) and septic failure (septic group), respectively. The postoperative range of motion (ROM), Western Ontario and McMaster Universities Osteoarthritis index, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), and infection rates were compared between the two groups.

Results

The mean follow-up durations in the aseptic and septic groups were 44.4 and 54.8 months, respectively. The septic group showed inferior postoperative ROM (124.1° and 109.4°, p = 0.004), KSKS (88.9 and 78.8, p = 0.001), and KSFS (72.8 and 59.0, p = 0.001). Three patients of aseptic group had infection. Three patients of septic group had recurred infection (same pathogen with the first infection) and 1 patient had a new infection (different pathogen). The septic group showed slightly higher but not significantly different infection rates (4.4% and 15.4%, p = 0.089).

Conclusions

Revision TKA with septic failure showed inferior postoperative clinical outcomes compared with aseptic revision surgery. A slightly higher infection rate was observed in the septic group but it was not significantly different.

A mapping review on preoperative prognostic factors and outcome measures of revision total knee arthroplasty

To map literature on prognostic factors related to outcomes of revision total knee arthroplasty (rTKA), to identify extensively studied factors and to guide future research into what domains need further exploration. We performed a systematic literature search in MEDLINE, Embase, and Web of Science. The search string included multiple synonyms of the following keywords: "revision TKA", "outcome" and "prognostic factor". We searched for studies assessing the association between at least one prognostic factor and at least one outcome measure after rTKA surgery. Data on sample size, study design, prognostic factors, outcomes, and the direction of the association was extracted and included in an evidence map. After screening of 5,660 articles, we included 166 studies reporting prognostic factors for outcomes after rTKA, with a median sample size of 319 patients (30 to 303,867). Overall, 50% of the studies reported prospectively collected data, and 61% of the studies were performed in a single centre. In some studies, multiple associations were reported; 180 different prognostic factors were reported in these studies. The three most frequently studied prognostic factors were reason for revision (213 times), sex (125 times), and BMI (117 times). Studies focusing on functional scores and patient-reported outcome measures as prognostic factor for the outcome after surgery were limited (n = 42). The studies reported 154 different outcomes. The most commonly reported outcomes after rTKA were: re-revision (155 times), readmission (88 times), and reinfection (85 times). Only five studies included costs as outcome. Outcomes and prognostic factors that are routinely registered as part of clinical practice (e.g. BMI, sex, complications) or in (inter)national registries are studied frequently. Studies on prognostic factors, such as functional and sociodemographic status, and outcomes as healthcare costs, cognitive and mental function, and psychosocial impact are scarce, while they have been shown to be important for patients with osteoarthritis.

Minimum 5 Year Clinical Outcomes And Survivorship For A Single Revision Total Knee Arthroplasty System Using Hybrid Fixation and Press-Fit Stems

BACKGROUND

Hybrid fixation, utilizing diaphyseal press-fit stems and cement fixation in the tibial and femoral metaphyseal areas, has long been a strategy for revision total knee arthroplasty (rTKA). The purpose of this study was to evaluate the clinical outcomes and survivorships of hybrid fixation using a single rTKA revision system with a minimum of 5 years follow-up.

METHODS

We reviewed our prospectively collected database to identify 281 patients who underwent rTKA using a single revision system with hybrid fixation and press-fit stems between July 2006 and August 2016. We reviewed the clinical outcome scores, including the Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, and Veterans RAND 12 Item Health Survey (VR-12). We also evaluated the 5- and 10-year survivorships and the indications for re-operations.

RESULTS

The cohort had a mean age of 70 years (range, x to y) and a mean body mass index of 33.4 (range, x to y). The mean time from rTKA surgery was 11.1 years (range, x to y). Above in yellow goes into ethods section Paired t-test analyses showed significant improvements from pre-operative versus post-operative clinical outcome scores (P<0.001) for KSS, WOMAC and VR-12 Physical component. Prosthetic joint infections after index rTKA was the most common failure mode with 29 patients requiring re-operations. Re-revision due to aseptic loosening was uncommon (6 patients) with a cumulative survival rate of 95.2% at 5 years and 94.2% at 10 years.

CONCLUSION

The use of this single rTKA system utilizing press fit stems combined with hybrid fixation provided significant improvements in the clinical outcomes and excellent survivorships at 5 and 10 years.

Allergy Testing Has No Correlation with Intraoperative Histopathology from Revision Total Knee Arthroplasty for Implant-Related Metal Allergy

Lymphocyte transformation testing (LTT) is often used in the workup for possible metal allergy after total knee arthroplasty (TKA) but the correlation of this test with other diagnostic metal-allergy findings in patients undergoing revision TKA for suspected metal allergy has not been established. A single-center, single-surgeon cohort of 19 TKAs in which both components were revised for presumed implant-related metal allergy based on history, physical, and LTT testing, to nonnickel-containing implants were retrospectively identified. Histopathologic samples obtained intraoperatively were semiquantitatively analyzed using both the Hospital for Special Surgery (HSS) synovial pathology score and the Campbell aseptic lymphocyte-dominant vasculitis-associated lesion (ALVAL) score. As histopathology control group, we included in the study an additional cohort of 17 patients who received aseptic revision TKA and had no history of reported or tested metal sensitivity. All preoperative LTT results were highly reactive to nickel. However, this did not correlate with local periarticular tissue response in 18 of 19 cases which demonstrated a low HSS synovial score (mean: 3.8 ± 2.8, of a maximum score of 28) and the low Campbell ALVAL scores (mean: 2.5/10 ± 1.3, of a maximum score of 10). There were not any significant differences between the study group (suspected implant-related metal allergy) and the control group (nonsuspected implant-related metal allergy) in regard to (1) the Campbell score and (2) the HSS synovial inflammatory score. Knee Society Clinical Rating System (KSCRS) function score improved significantly after revision (mean postoperative increase: 34.0 ± 17. 2; p < 0.001), as well as mean visual analog scale (VAS) pain (mean postoperative decrease: 33.3 ± 26.4; p < 0.01) score. The short-term survival rate (at mean follow-up of 26.1 months) of this patient cohort was 100%. In this cohort of revised TKA patients with suspected nickel allergy based on clinical presentation and LTT positive results, intraoperative histopathology was essentially normal. However, all patients with suspected nickel allergy showed a significant clinical and functional improvement with excellent short-term survival rates. The clinical significance of a positive LTT needs further study.

Factors affecting range of motion following two-stage revision arthroplasty for chronic periprosthetic knee infection

Introduction

The purpose of this study was to evaluate factors that affect range of motion (ROM) following two-stage revision arthroplasty as a treatment for chronic periprosthetic knee infection.

Materials and methods

A total of 98 patients diagnosed with chronic periprosthetic joint infection (PJI) following primary total knee arthroplasty between January 2009 and December 2019 and then underwent two-stage revision arthroplasty were reviewed retrospectively. Multiple regression analysis was performed to evaluate the factors that affect ROM after two-stage revision arthroplasty. ROM after two-stage revision arthroplasty was used as a dependent variable, while age at the time of surgery, ROM at PJI diagnosis, ROM after the first-stage surgery, the interval between the first-stage surgery and the second-stage surgery, whether a re-operation was performed before the second-stage surgery, culture results (culture negative or culture positive), and body mass index (BMI) were used as independent variables.

Results

Multiple regression analysis (R2 = 0.843) revealed that among the independent variables, ROM (β = 0.604, P < 0.001) after the first-stage surgery, whether a re-operation was performed before the second-stage surgery (β =  − 8.847, P < 0.001), the interval between the first-stage surgery and the second-stage surgery (β = − 0.778, P = 0.003), and BMI (β =  − 0.698, P = 0.041) were associated with ROM after two-stage revision arthroplasty, the dependent variable.

Conclusions

In two-stage revision arthroplasty for chronic periprosthetic knee infection, ROM after the first-stage surgery, whether a re-operation was performed before the second-stage surgery, the interval between the first-stage surgery and the second-stage surgery, and BMI were found to be factors that were associated with ROM after two-stage revision arthroplasty.

Treatment of arthrofibrosis and stiffness after total knee arthroplasty: an updated review of the literature

PURPOSE

There is currently no consensus regarding the optimal treatment for stiffness following total knee arthroplasty (TKA). With the increased utilization of value-based models, it is important to determine the most effective treatments that will reduce the need for further intervention and additional expenditure. A systematic review was performed to compare the outcomes of manipulation under anaesthesia (MUA), arthroscopic lysis of adhesions (aLOA), and revision TKA (rTKA) for arthrofibrosis and stiffness following TKA.

METHODS

PubMed and MEDLINE databases were reviewed for articles published through October 2020. Studies were included if they reported patient-reported outcome measures (PROMs) following MUA, aLOA, or rTKA. The primary endpoint was PROMs, while secondary outcomes included range of motion and the percentage of patients who pursued further treatment for stiffness.

RESULTS

A total of 40 studies were included: 21 on rTKA, 7 on aLOA, and 14 on MUA. The mean or median post-operative arc ROM was > 90° in 6/20 (30%) rTKA, 5/7 (71%) aLOA, and 7/10 (70%) MUA studies. Post-operative Knee Society (KSS) clinical and functional scores were the greatest in patients who underwent MUA and aLOA. As many as 43% of rTKA patients required further care compared to 25% of aLOA and 17% of MUA patients.

CONCLUSION

Stiffness following TKA remains a challenging condition to treat. Nonetheless, current evidence suggests that patients who undergo rTKA have poorer clinical outcomes and a greater need for further treatment compared to patients who undergo MUA or aLOA.

Increased Prevalence of Depressive Symptoms in Patients Undergoing Revision for Periprosthetic Joint Infection

Background

Periprosthetic joint infection (PJI) is a devastating complication after total joint arthroplasty. Patients undergoing revision for PJI may experience psychological distress and symptoms of depression, both of which are linked to poor postoperative outcomes. We, therefore, aim to identify the prevalence of depression and depressive symptoms in patients before treatment for PJI and their link to functional outcomes.

Methods

Patients undergoing either debridement with implant retention (DAIR) or 2-stage exchange for PJI with minimum 1-year follow-up were retrospectively reviewed. The 2-stage (n = 37) and single-stage (n = 39) patients that met inclusion criteria were matched based off age (±5 years), gender, and body mass index (±5) to patients undergoing aseptic revisions. Outcomes evaluated included a preoperative diagnosis of clinical depression and preoperative and postoperative Veterans RAND 12 Item Health Survey mental component score and physical component score.

Results

Compared to matched controls, the prevalence of depressive symptoms was significantly greater in patients undergoing 2-stage exchange preoperatively (40.5% vs 10.8%, P < .01) but not postoperatively (21.6% vs 10.8%, P = .20). Patients undergoing DAIR with either preoperative depressive symptoms (31.3 vs 40.9, P = .05) or a preoperative diagnosis of depression (27.7 vs 43.1, P < .01) had significantly lower physical component scores postoperatively.

Conclusions

Patients undergoing 2-stage exchange for PJI have a four times higher prevalence of preoperative depressive symptoms than patients undergoing aseptic revision. Patients undergoing DAIR with depression or preoperative depressive symptoms have lower functional scores postoperatively. Orthopedic surgeon screening of PJI patients with referral for treatment of depression may help improve outcomes postoperatively.

Outcomes in revision total knee arthroplasty (Review)

Revision total knee arthroplasty (TKA) is a challenging surgical procedure. Although good results are presented, the outcomes are worse in comparison with those of primary TKA, with a higher failure rate. The main reasons for the failure of revision TKA include: sepsis, loosening and instability. There are multiple variables linked to these results, and it is difficult to determinate the exact cause as it is often a multifactorial issue. These variables may be related to the quality of the index-procedure (TKA), to the revision procedure or to patient characteristics. The purpose of this review was to highlight the outcomes of revision knee arthroplasty and main factors that may influence the results. Considerable progress has been made during the last 30 years regarding infection treatment and prevention, complex revision prosthetic design and surgical technique development. Although the outcomes have improved over time, patients who undergo revision TKA may need further re-operations in the future.

Poor outcomes of revision total knee arthroplasty in patients with septic loosening compared to patients with aseptic loosening

Background

The purpose of this study was to compare the functional outcomes, activity levels, mortalities, implant survival rates, and complications in revision total knee arthroplasty (TKA) of patients with septic loosening with those in patients with aseptic loosening over a minimum 10-year follow-up period.

Methods

A cohort of 78 patients (36 septic loosening and 42 aseptic loosening) was selected between January 2008 and December 2009. The functional outcomes, activity levels, mortalities, implant survival rates, and complications of revision TKA in patients with septic and aseptic loosening were compared.

Results

The mean Knee Society knee scores in the septic and aseptic groups improved from 36.7 and 37.4 preoperatively to 65.3 and 76.8 points at the final follow-up, respectively (p < 0.05). Outdoor ambulatory patients at the final follow-up included 20 of 29 (69.0%) patients in the septic group and 35 of 39 (89.7%) patients in the aseptic group (p < 0.05). The cumulative mortality rates in the septic and aseptic groups were 19.4% (7/36) and 7.1% (3/42) (p = 0.102) at final follow-up, respectively. Kaplan–Meier survivorship analysis with re-revision of either component as an endpoint in the septic and aseptic groups estimated 86.5% and 95.5% chance of survival for 10 years, respectively.

Conclusions

Revision TKA in patients with septic loosening had worse functional outcomes and higher mortality over a minimum 10-year follow-up period compared with that in patients with aseptic loosening.

Level of evidence

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.

Preoperative Mental Health Influences Patient-Reported Outcome Measures and Satisfaction After Revision Total Knee Arthroplasty

BACKGROUND

A higher prevalence of mental health conditions has been reported in patients undergoing revision total knee arthroplasty (rTKA). This study investigated the effect of preoperative mental health on patient-reported outcome measures (PROMs) and satisfaction after rTKA.

METHODS

A total of 245 patients who underwent rTKA in 2004-2018 were identified from our institutional joint registry. The most common indications were aseptic loosening (n = 111), infection (n = 70), and instability (n = 35). 36-item Short-Form health survey (SF-36) mental component summary (MCS) was used to stratify the cohort into: Low-MCS (SF-36 MCS <50; n = 112) and control (SF-36 MCS ≥50; n = 133) groups. Knee Society score, Oxford knee score, SF-36 physical score, and a satisfaction questionnaire were used to compare the low-MCS and control at 6 months and 2 years.

RESULTS

All PROMs were poorer in the low-MCS group at 6 months and 2 years. However, both groups demonstrated a comparable improvement in each PROM and a similar proportion attained the minimal clinically important difference. Fewer patients in the low-MCS group were satisfied at 2 years (72.2% vs 84.5%, P = .045). Lower preoperative SF-36 MCS was independently associated with increased odds of dissatisfaction (OR 1.037, 95% CI 1.004-1.070, P = .027). Although the change in SF-36 MCS was greater in the low-MCS group, the final value remained lower at 2 years.

CONCLUSION

While patients with poor mental health had inferior PROMs preoperatively and postoperatively, a similar percentage experienced a clinically meaningful improvement at 2 years. Perioperative optimization of psychological factors should still be emphasized as these patients were at a higher risk of dissatisfaction after rTKA.

Effectiveness of two rehabilitation treatments in the modulation of inflammation during the acute phase in patients with knee prostheses and assessment of the role of the diet in determining post-surgical inflammation

Clinical trial number

NCT04580069.

Background

Total knee arthroplasty is associated with an elevated inflammatory response both at a local and systemic level. The main objective of this study is to demonstrate the effectiveness of lymphatic drainage and connective tissue techniques in modulating systemic inflammation. Another objective is to evaluate the existence, at baseline, of a correlation between the inflammation indices and the level of adherence to the Mediterranean diet.

Methods

34 patients were recruited, and divided into three groups. The control group followed the normal rehabilitation protocol. The other two groups were subjected, in addition to the standard treatment, to manual lymphatic drainage treatment or connective tissue techniques. The outcomes were recorded in three stages: upon entering the hospital, 1 week after entry and at follow-up 21 days after surgery.

Results

The results of the study showed that both methods, compared with the standard treatment only, positively influenced the final outcomes. In regard to the systemic inflammation, lymphatic drainage and connective techniques showed equal efficacy and similar timing in modulating ESR, while they differ in how they affect CRP. With regard to the local inflammation, the effectiveness of both methods was confirmed with some differences in the location. Finally, analysis of the correlation between inflammatory T0 indices and adherence to the Mediterranean diet showed that patients with higher adhesion index have on average lower PCR, EDO and EDU values.

Conclusions

The post-surgical inflammatory pattern can be positively modified by the rehabilitation methods analyzed, albeit with different methodologies and timing.The influence of the diet on inflammatory parameters, although less evident, seems to show encouraging results worth of further studies.

Do Prosthetic Joint Infections Worsen the Functional Ambulatory Outcome of Patients with Joint Replacements? A Retrospective Matched Cohort Study

OBJECTIVES

To assess the effect on the functional ambulatory outcome of postoperative joint infection (PJI) cured at the first treatment attempt versus not developing PJI in patients with hip and knee prostheses.

METHODS

In a single-hospital retrospectively matched cohort study, each patient with PJI between 2007 and 2016 was matched on age, sex, type of prosthesis and year of implantation with two other patients with uninfected arthroplasties. The definition of a PJI cure included infection eradication, no further surgical procedures, no PJI-related mortality and no suppressive antibiotics. Functional ambulatory status evaluated one year after the last surgery was classified into four simple categories: able to walk without assistance, able to walk with one crutch, able to walk with two crutches, and unable to walk. Patients with total hip arthroplasties (THA), total knee arthroplasties (TKA) and partial hip arthroplasty (PHA) were analysed separately.

RESULTS

A total of 109 PJI patients (38 TKA, 41 THA, 30 PHA) and 218 non-PJI patients were included. In a model adjusted for clinically relevant variables, PJI was associated with a higher risk of needing an assistive device for ambulation (vs. walking without aid) among THA (adjusted odds ratio (OR) 3.10, 95% confidence interval (95% CI) 1.26-7.57; p = 0.014) and TKA patients (OR 5.40, 95% CI 2.12-13.67; p < 0.001), and with requiring two crutches to walk or being unable to walk (vs. walking unaided or with one crutch) among PHA patients (OR 3.05, 95% CI 1.01-9.20; p = 0.047).

CONCLUSIONS

Ambulatory outcome in patients with hip and knee prostheses with postoperative PJI is worse than in patients who do not have PJI.

Patient-reported Outcome Measures of Revision Total Hip Arthroplasty for Prosthetic Joint Infection is not Inferior to Aseptic Revision Total Hip Arthroplasty

Introduction:

This study aims to investigate whether patients undergoing two-stage revision total hip arthroplasty (THA) for prosthetic joint infection (PJI) and one-stage revision THA for aseptic reasons have similar clinical outcomes and patient satisfaction during their post-operative follow-up. We hypothesise that the two-stage revision THA for PJI is associated with poorer outcomes as compared to aseptic revision THA.

Materials and Methods:

We reviewed prospectively collected data in our tertiary hospital arthroplasty registry and identified patients who underwent revision THA between 2001 and 2014, with a minimum of two years follow-up. The study group (two-stage revision THA for PJI) consists of 23 patients and the control group (one-stage revision THA for aseptic reasons) consists of 231 patients. Patient demographics, Western Ontario and McMaster Universities Arthritis Index (WOMAC), Oxford Hip Score (OHS), Short Form-36 (SF-36) scores and patient reported satisfaction were evaluated. Student’s t-test was used to compare continuous variables between the two groups. Statistical significance was defined as p <0.05.

Results:

The pre-operative demographics and clinical scores were relatively similar between the two groups of patients. At two years, patients who underwent revision THA for PJI reported a better WOMAC Pain Score and OHS as compared to aseptic revision THA. A similar proportion of patients were satisfied with their results of surgery in both groups (p=0.093).

Conclusions:

Although patients who underwent revision THA for PJI had poorer pre-operative functional scores (WOMAC function and SF-36 PF), at two years follow-up, these two groups of patients have comparable post-operative outcomes. Interestingly, patients who had revision THA for PJI reported a better clinical outcome in terms of OHS and WOMAC Pain score as compared to the aseptic group. We conclude that the revision THA for PJI is not inferior to aseptic revision THA in terms of patient satisfaction and clinical outcomes.

Periprosthetic Joint Infection in Patients Who Have Multiple Prostheses in Place: What Should Be Done with the Silent Prosthetic Joints

BACKGROUND

Although periprosthetic joint infection (PJI) can affect multiple joints concurrently, the majority of patients with multiple prosthetic joints present with PJI of a single joint. Data regarding the optimal management of these patients are limited. We aimed to identify the prevalence, risk factors for a subsequent PJI, and clinical circumstances of PJI in patients with multiple prosthetic joints.

METHODS

We retrospectively reviewed the clinical records of 197 patients with ≥2 total joint prostheses in place who presented with PJI from 2000 to 2017. The average follow-up was 3.6 years (range, 0.5 to 17 years). Demographic data and risk factors for synchronous or metachronous PJI were identified. The time from the initial to the second PJI and organism profile data were collected as well. The workup for other joints with a prosthesis in place at the time of the initial PJI was noted.

RESULTS

Among the 197 patients with PJI and multiple joint prostheses in situ, 37 (19%) developed PJI in another joint; 11 had a synchronous PJI and 26 had a metachronous PJI. The average time between the first and the second infection in the metachronous cases was 848 days (range, 20 to 3,656 days). Females and patients with an initial PJI with methicillin-resistant Staphylococcus aureus (MRSA) were more likely to have a metachronous PJI, and patients with rheumatoid arthritis had an increased risk of a second (metachronous or synchronous) PJI. Three of 11 patients in the synchronous group and 19% (5) of the 26 in the metachronous group had bacteremia at the time of the initial PJI compared with 12% (19) of the 160 with a single PJI. The percentage of negative cultures increased from 10% for the initial PJIs to 38% for the metachronous PJIs.

CONCLUSIONS

Patients who have multiple prosthetic joints in place and present with PJI of a single joint are at risk of developing PJI in another joint. Female sex, rheumatoid arthritis, bacteremia at presentation, and infection with MRSA appear to be risk factors for PJI of another joint. Clinical evaluation of the other prosthetic joint(s) should be carried out in all patients and aspiration of those joint(s) should be considered for patients with any of the above risk factors.

LEVEL OF EVIDENCE

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

Long-Term Outcome Following Revision Total Knee Arthroplasty is Associated With Indication for Revision

BACKGROUND

There is limited information about long-term clinical outcomes following revision total knee arthroplasty (TKA) in relation to the indication for revision. Previously, a clear relation between indication for revision and clinical outcome was shown after 2 years. Present study evaluated (1) whether the reported association at 2 year remains present at 7.5 years, and (2) how clinical outcome at 7.5 years developed compared to baseline and 2-year follow-up, and (3) whether patients had additional adverse events.

METHODS

A cohort of 129 patients with a total system revision TKA was selected. Range of motion, Visual Analog Scale for pain and satisfaction, and clinical and functional Knee Society Score were obtained preoperatively, at 3 months, 1, 2, and 7.5 years. Reasons for revision were septic loosening, aseptic loosening, malposition, instability, and severe stiffness.

RESULTS

Patients revised for severe stiffness had significantly worse outcomes. No difference was found between the other indications. The clinical outcome after revision TKA at 7.5 years remained stable for septic and aseptic loosening, malposition, and instability but deteriorated slightly for the severe stiffness group. Visual Analog Scale satisfaction remained constant for all indications. There were 11 additional complications between 2- and 7.5-year follow-up, 9 of which necessitated reoperation.

CONCLUSION

All indications except severe stiffness had a similar clinical outcome which was maintained up to 7.5-year follow-up. The severe stiffness group had worse outcomes and deteriorated slightly at longer follow-up. Outcome at 3 months seems predictive for long-term outcome. Additional complications did not differ significantly for the different reasons for revision.

LEVEL OF EVIDENCE

Level III, prognostic study.

Major Aseptic Revision Following Total Knee Replacement: A Study of 478,081 Total Knee Replacements from the Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

Major revision is associated with less satisfactory outcomes, substantial complications, and added cost. Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) were analyzed to identify factors associated with major aseptic revision (MAR) of primary total knee replacement (TKR).

METHODS

The cumulative percent major aseptic revision rate following all primary TKRs performed in Australia from September 1, 1999, to December 31, 2015, was assessed. Kaplan-Meier estimates of survivorship were utilized to describe the time to first revision. Hazard ratios (HRs) from Cox proportional hazard models, adjusted for age and sex, were utilized to compare revision rates.

RESULTS

There were 5,973 MARs recorded from the total cohort of 478,081 primary TKRs. The cumulative percent MAR at 15 years was 3.0% (95% confidence interval [CI], 2.8% to 3.2%). Fixed bearings had a significantly lower rate of MAR at 15 years: 2.7% (95% CI, 2.4% to 2.9%) compared with 4.1% (95% CI, 3.8% to 4.5%) for mobile bearings (HR, 1.77 [95% CI, 1.68 to 1.86]; p < 0.001). Age had a significant effect on MAR rates, with a cumulative percent revision at 15 years for patients <55 years old of 7.8% (95% CI, 6.5% to 9.2%) compared with 1.0% for those ≥75 years old (95% CI, 0.8% to 1.1%; p < 0.001). Minimally stabilized TKR had a lower rate of MAR compared with posterior-stabilized TKR after 2 years (HR, 0.83 [95% CI, 0.77 to 0.90]; p < 0.001). Cementless fixation had a higher rate of revision than cemented or hybrid fixation. There was a higher rate of MAR with non-navigated compared with computer navigated TKR (HR, 1.32 [95% CI, 1.21 to 1.44], p < 0.001). The tibial component was revised more commonly than the femoral component.

CONCLUSIONS

Younger age, posterior stabilization, cementless fixation, a mobile bearing, and non-navigation were risk factors for higher rates of MAR following TKR.

LEVEL OF EVIDENCE

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

Clinical and radiographic outcomes of a hybrid fixation revision total knee arthroplasty system at short to mid-term follow-up

BACKGROUND

Despite the extensive study of primary arthroplasty, revision surgery is rarely discussed due to the reduced frequency and variability between patients. A new revision knee system was introduced to build off the geometry of a successful knee replacement system. This study seeks to assess the survival, clinical outcomes and radiographic assessment of this revision system at the early to mid-term.

METHODS

A consecutive cohort of 234 rTKAs was identified from an institutional database. Survival analysis was assessed for aseptic loosening and any-cause failure. Patient outcome measures were the Oxford Knee Score (OKS) and patient reported satisfaction. Radiographs were assessed in accordance with the Knee Society radiographic scoring system. Mechanical alignment was assessed on three-foot standing radiographs.

RESULTS

Aseptic survivorship at one year, two years, and five years was 100%, 100%, and 99.1%, respectively. Any-cause survival at one, two, and five years was 99.6%, 98.7%, and 92.3%, respectively. OKS improved from pre-op (average 18.8) to one year (average 31.7), two years (average 30.7), and mid-term (average 30.6) follow-up (p < 0.001 for all). At all intervals, patient satisfaction exceeded 70%. One component (0.4%) failed radiographically and was later revised. Neutral mechanical alignment was achieved in 83% of cases. In the remaining cases, alignment was in varus (10%) or valgus (seven percent). No consistent relationship between radiographs or mechanical alignment and clinical outcomes was noted.

CONCLUSION

The survivorship, clinical, and radiographic outcomes of the single rTKA system studied are equivalent or superior to other hybrid fixation rTKA systems reviewed in the literature at similar follow-up intervals.

Age, gender, functional KSS, reason for revision and type of bone defect predict functional outcome 5 years after revision total knee arthroplasty: a multivariable prediction model

PURPOSE

The number of revision total knee arthroplasties (rTKA) is increasing. Unfortunately, not all patients benefit from revision surgery. The aim of this study was to develop a clinical prediction model that can be used to predict the functional outcome 5 years after rTKA.

METHODS

Data of patients receiving rTKA at Sint Maartenskliniek, Nijmegen, The Netherlands, from 2004 onwards were prospectively collected. Demographic and clinical variables and patient-reported outcome scores were collected and considered as potential predictors. Beneficial outcome was defined as an increase of ≥ 20 points on the functional knee society scores (fKSS) or an absolute fKSS ≥ 80 points 5 years after surgery. The prediction model was developed using backward logistic regression. Regression coefficients were converted into an easy to use prediction rule.

RESULTS

Overall, 295 rTKA patients were included of whom 157 (53%) had beneficial fKSS 5 years later. Age, gender, femoral bone defects, preoperative fKSS, and stiffness as reason for revision were included in the model. Men had a higher chance of beneficial fKSS than women (OR 1.59, 95% CI 0.91-2.78). Patients with major bone defects (OR 0.44, 95% CI 0.22-0.85), higher age (IQR OR 0.39, 95% CI 0.26-0.58), higher preoperative fKSS (IQR OR 0.42, 95% CI 0.30-0.59), and severe stiffness (OR 0.48, 95% CI 0.20-1.15) had a lower chance of successful outcome. The model's AUC was 0.76, 95% CI 0.70-0.81.

CONCLUSION

Easily determinable characteristics of patients who need rTKA can be used to predict future functional outcome. Young men with low preoperative fKSS without severe stiffness are more likely to achieve a beneficial outcome.

LEVEL OF EVIDENCE

IV.

Assessment and management of infected total knee replacements

Infection following total knee replacement surgery is a challenging and devastating complication. Clinical assessment including history, examination, radiographs, blood tests and knee aspirations helps to establish the diagnosis. Revision surgery is typically required to eradicate infection and restore function. This has traditionally been performed through two-stage revision surgery, although single-stage revision surgery is gaining popularity with comparable results in carefully selected patients. This article reviews the clinical assessment and principles of surgical management of infected total knee replacements.

Efficacy of Revision Surgery for the Treatment of Stiffness After Total Knee Arthroplasty: A Systematic Review

BACKGROUND

Knee stiffness following total knee arthroplasty (TKA) may cause pain and reduced functionality, contributing to unsatisfactory surgical outcomes. Revision surgery remains a possible treatment for refractory postoperative stiffness. However, the efficacy of the procedure has not been systematically evaluated.

METHODS

A systematic review of the literature was performed to identify studies that reported on outcomes for patients who underwent revision surgery for postoperative stiffness after TKA.

RESULTS

Ten studies (including 485 knees) were reviewed. The most common etiologies of stiffness requiring revision TKA were component malposition, malalignment, overstuffing, aseptic loosening, arthrofibrosis, patella baja, and heterotopic ossification. Of 9 studies reviewing range of motion outcomes after revision TKA, 7 studies documented significant improvement and 2 found trends toward improvement. Seven of 8 studies documenting Knee Society knee scores and 7 of 9 studies documenting functional scores found improvement after revision TKA. All studies reporting on pain found improvement at final follow-up after revision TKA.

CONCLUSION

Revision TKA results in increased range of motion, improved functionality, and reduced pain in most patients who require surgery for stiffness. The present literature is inadequate to predict which patients will achieve adequate outcomes from revision TKA based on the specific etiology of their stiffness, although identification of the etiology may help in surgical planning. Surgeons performing revision TKA should counsel patients on the risks and benefits of undergoing revision surgery, with the understanding that outcomes for well-selected patients are generally favorable.

Periprosthetic Joint Infection Does Not Preclude Good Outcomes after a Revision Total Knee Arthroplasty: A 7-Year Follow-Up Study of 144 Retrospective Cases

Background and Purpose

Debate exists on whether septic revision total knee arthroplasty (TKA) results in inferior clinical outcomes, and limited information is available regarding the factors associated with such outcomes. This study aimed to (1) compare clinical outcomes and characteristics of aseptic versus septic revision TKA and (2) identify the risk factors associated with inferior clinical outcomes.

Methods

We retrospectively reviewed 144 revision TKAs (90 aseptic and 54 septic revisions) that were followed for a minimum of 3 years (mean = 7 years). Clinical outcome data, namely, Knee Society knee and function scores and the Hospital for Special Surgery knee score, were collected. We reviewed 13 pre- and intraoperative variables.

Results

Postoperative clinical outcomes were inferior in septic revision surgeries (p<0.05). In regression analyses, however, septic revision was not an independent risk factor for poor clinical outcomes. The independent risk factors for poor outcome were identified where Anderson Orthopedic Research Institute grade 3 femoral and tibial bone defects, more than three surgeries, and treatment for persistent infection were associated with inferior clinical outcomes (all p<0.05). Standard two-stage septic revision without grade 3 bone defects or additional surgeries showed comparable outcomes to aseptic revision.

Interpretation

Clinical outcomes of septic revision were inferior to those of aseptic revision. However, poor outcomes were mainly associated with large bone defects and an increased number of surgeries. The outcomes of aseptic and septic revision surgery were similar when patients with larger bone defects and more than three surgeries were excluded.

Causes and Clinical Outcomes of Revision Total Knee Arthroplasty

Purpose

The purpose of this study was to evaluate causes and clinical outcomes of revision total knee arthroplasty (TKA) with a minimum 2-year follow-up.

Materials and Methods

We performed a retrospective review on the records of 225 revision TKAs performed from 2003 to 2012 at a single institution. Finally, 206 cases were conducted. To evaluate clinical outcomes, we checked the range of motion (ROM), Knee Society (KS) score, Hospital for Special Surgery (HSS) score, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score preoperatively, 6 months postoperatively and yearly thereafter and complications after revision TKA.

Results

The causes of revision TKA were septic complications in 120 and aseptic complications in 86. The main aseptic complication was periprosthetic fracture in 36, followed by 25 loosening, 13 polyethylene wear and 9 instability. At the final follow-up, patients showed improvements in ROM and KS, HSS and WOMAC scores. Of the total, 7 patients underwent re-revision due to reinfection in 6 and periprosthetic fracture in 1.

Conclusions

Due to development of implants and surgical techniques, mechanical complications such as aseptic loosening and instability that need a revision decreased whereas septic complications relatively increased. Therefore, we should be cautious for the occurrence of infection. Overall, revision TKA provided clinical improvement in knee function and patient satisfaction.

Can a Silver-Coated Arthrodesis Implant Provide a Viable Alternative to Above Knee Amputation in the Unsalvageable, Infected Total Knee Arthroplasty?

BACKGROUND

In the unsalvageable, infected total knee arthroplasty, knee arthrodesis is one treatment option with lower reported reinfection rates compared with repeated 2-stage revision and improved function compared with amputation. One possible method for reducing incidence of recurrent infection treated by arthrodesis is the use of a silver-coated implant. We report our experience of silver-coated arthrodesis nails used for managing infected revision arthroplasty. We primarily assess the rate of reinfection and rate of amputation and report functional outcome measures.

METHODS

Retrospective analysis of all patients undergoing knee arthrodesis with a silver-coated arthrodesis nail between 2008 and 2014. Patient-reported data were recorded prearthrodesis and postarthrodesis (Oxford Knee Score and Short Form-36) as well as evidence of recurrent of infection, subsequent surgery, and the necessity for amputation.

RESULTS

Eight patients underwent arthrodesis using the silver-coated arthrodesis nail. Mean duration of follow-up was 16 months (5-35 months). At the point of follow-up, there were no amputations, deaths, or implant revisions. One case of recurrent infection was successfully treated with washout and debridement. The mean prearthrodesis and postarthrodesis Oxford Knee Score difference was +8.9 points (P = .086) with significantly improved pain (P = .019), night pain (P = .021), and ease of standing (P = .003).

CONCLUSION

Arthrodesis of the knee using a silver-coated intramedullary device is successful in eradicating infection and allowing limb conservation. Where infection does recur, this can be successfully treated with implant retention. The use of a silver-coated arthrodesis nail should be considered as an alternative to amputation for patients with a multiply revised and infected total knee arthroplasty.

Moderate clinical improvement after revision arthroplasty of the severely stiff knee

PURPOSE

Revision of the severe stiff total knee arthroplasty (TKA) is challenging, and clinical outcome is inferior to other indications for revision. The purpose of the present study was to determine clinical outcome of TKA revision in patients with severe stiffness (range of motion (ROM) ≤ 70°) and evaluate a possible influence of accompanying findings, such as component malposition, aseptic loosening or instability.

METHODS

A prospective cohort of 40 patients with a preoperative ROM ≤ 70° and a minimum of 2-year follow-up after total system revision (Genesis or Legion stemmed condylar implant) was evaluated. ROM, Knee Society Scoring System (KSS) and visual analogue scale (VAS) pain scores were obtained preoperatively and at 2 years. Patient satisfaction and complication rate were assessed. Component malposition was most frequently reported as accompanying finding (n = 27). Comparisons between pre- and postoperative outcome (p < 0.05) and between different subgroups (component malposition, aseptic loosening, and instability) based on accompanying findings were made (no statistical comparison).

RESULTS

ROM, KSS and VAS pain scores improved significantly (p < 0.001): median ROM at two years 85° (range 10-125) and median gain 25° (range -10 to +85). Median VAS satisfaction was 53.5 points (range 15-98). Seventeen patients reported at least one complication, including one re-revision. Six patients underwent manipulation under anaesthesia, and five were referred to the pain clinic. No clear differences between subgroups were observed.

CONCLUSIONS

TKA revision in patients with severe stiffness resulted in a moderate but significant improved clinical outcome after 2 years. Accompanying abnormalities such as component malposition, aseptic loosening or instability did not influence clinical outcome. Realistic patient counselling on the moderate outcome and possible remaining limitations in daily life might help to improve patient satisfaction.

LEVEL OF EVIDENCE

Therapeutic studies-case series with no comparison group, Level IV.

Influence of the cause of the revision on the outcome after revision knee arthroplasty with condylar constrained implant

INTRODUCTION

Revision total knee arthroplasty (TKA) is a common procedure with varying results depending on the cause. Our objective was to compare the clinical and radiological outcomes in patients undergoing aseptic revision versus revision due to prosthetic infection.

MATERIAL AND METHODS

The study included 41 patients who underwent TKA revision with the same varus-valgus constrained implant. In all cases a clinical evaluation was performed including pain, range of motion (ROM), Knee Society Score (KSS), complications, as well as radiological study. A comparative analysis was performed on the pre- and postoperative results between septic and aseptic groups. The mean follow-up was 6 years.

RESULTS

ROM had a mean increase of 17 degrees (p<.01). KSS and functional KSS improved significantly postoperatively. In the radiological study, joint interline and limb alignment were restored in all cases. Radiolucencies were found in 36.5% of cases; however they were unrelated to the appearance of loosening of the implant. There were complications in 29.2% of cases, mostly related to the surgical wound. Mobility, KSS, KSS functional and satisfaction at follow-up were better in the septic group. Implant survival was 95% at follow-up.

CONCLUSION

Revision arthroplasty with constrained varus-valgus implant is safe, and has successful mid-term results despite the cause of the replacement procedure.

How are we addressing ligament balance in TKA? A literature review of revision etiology and technological advancement

Despite technological advances in operative technique and component materials, the total knee arthroplasty (TKA) revision burden, in the United States, has remained static for the past decade. In light of an anticipated exponential increase in annual surgical volume, it is important to thoroughly understand contemporary challenges associated with technologically driven TKA. This descriptive literature review harvested 69 relevant publications to extrapolate patient trends, benefits, costs, and complications associated with computer-assisted surgery, patient specific instrumentation, and intra-operative sensors. Due to additional charges, a steep learning curve, and questionable cost-effectiveness, widespread use of these systems has been limited. Intra-operative sensors are a relatively recent development, and have been shown to improve both soft-tissue balance and overall functional outcomes at a relatively low price and without disrupting operative workflow. The introduction of new technology into the operating suite should be considered carefully, especially with respect to combined clinically efficacy and cost.

Short term outcomes of revision total knee arthroplasty

Few studies have assessed postoperative complications in revision total knee arthroplasty (rTKA). The aim of this study was to assess which preoperative factors are associated with postoperative complications in rTKA. Using the National Surgical Quality Improvement (NSQIP) database, we identified patients undergoing rTKA from 2010 to 2012. Patient demographics, comorbidities, and complications within thirty days of surgery were analyzed. A total of 3421 patients underwent rTKA. After adjusted analysis, dialysis (P = 0.016) was associated with minor complications. Male gender (P = 0.03), older age (P = 0.029), ASA class >2 (P = 0.017), wound class >2 (P < 0.0001), emergency operation (P = 0.038), and pulmonary comorbidity (P = 0.047) were associated with major complications.

Predictors of pain medication use for arthroplasty pain after revision total knee arthroplasty

OBJECTIVE

Our objective was to study the use of pain medications for persistent knee pain and their predictors after revision total knee arthroplasty (TKA).

METHODS

We examined whether demographic (gender, age) and clinical characteristics [BMI, co-morbidity measured by the Deyo-Charlson index (a 5-point increase), anxiety and depression] predict the use of NSAIDs and narcotic pain medications 2 and 5 years after revision TKA. Multivariable logistic regression adjusted for these predictors as well as operative diagnosis, American Society of Anesthesiologists class and distance from the medical centre.

RESULTS

A total of 1533 patients responded to the 2-year questionnaire and 881 responded to the 5-year questionnaire. NSAID use was reported by 13.4% (206/1533) of patients at 2 years and 16.7% (147/881) at 5 years. Narcotic medication use was reported by 5.4% (83/1533) of patients at 2 years and 5.9% (52/881) at 5 years. Significant predictors of the use of NSAIDs for index TKA pain at 2 and 5 years were age >60-70 years [odds ratio (OR) 0.62 (95% CI 0.39, 0.98) and 0.46 (0.25, 0.85)] compared with age ≤60 years and a higher Deyo-Charlson index [OR 0.51 (95% CI 0.28, 0.93)] per 5-point increase at 5-year after revision TKA. Significant predictors of narcotic pain medication use for index TKA pain were age >60-70 years [OR 0.41 (0.21, 0.78)] and >70-80 years [0.40 (95% CI 0.22, 0.73)] at 2 years and depression [OR 4.58 (95% CI 1.58, 13.18)] at 5 years.

CONCLUSION

Younger age and depression were risk factors for the use of NSAIDs and narcotic pain medications for index TKA pain at 2- and 5-years after revision TKA.

Periprosthetic joint infection--effect on quality of life

PURPOSE

Relatively little is known about the extent to which periprosthetic joint infections (PJI) affect the patient's long-term quality of life (QoL). Our study aim was to assess the effect of a periprosthetic infection on our patients' QoL.

METHODS

We collected data retrospectively of patients who had undergone surgery in our institution between 2006 and 2011. To capture their overall QoL, we telephoned the patients who could be reached and asked them the questions on the SF-12 questionnaire.

RESULTS

In 84 patients (53 male, 31 female, 43 TKA and 41 THA), 88 % of the hip infections and 62 % of the knee infections had been successfully treated. The hip infections' cure rate was significantly higher than that of the knee joint infections. The average SF-12 score was 36.2 points on the physical scale and 52 on the mental scale. The difference in QoL between patients with and without successful infection therapy was not significant, nor did the site of the infection (knee or hip) influence QoL significantly. Comparison of our patients' QoL data to that from the general population revealed a significant difference in the physical scale but not the mental scale.

CONCLUSION

From these results QoL is substantially reduced after a prosthetic infection. We did however observe that post-Girdelstone procedure patients or those with an arthrodesis attained an acceptable QoL, and that those methods remain therapeutic alternatives as far as patient-perceived QoL is concerned.

Predictors of functional outcome after revision total knee arthroplasty following aseptic failure

BACKGROUND

There are a limited number of studies related to quality of life and functional outcome after revision total knee arthroplasty (TKA). The present study aimed to identify predictors of functional outcome after revision TKA for aseptic failure.

METHODS

One hundred seventy-five patients with mean age of 66.6 years (range, 35-88) who underwent revision TKA for aseptic failure at our institute from 2003 to 2007 were identified. Short-form 36 (SF-36), Western Ontario and McMaster Osteoarthritis Index (WOMAC) and Knee Society Scores (KSS) collected preoperatively and at 2 years follow up were evaluated. Univariate and multivariate analyses were performed to determine predictors of functional outcome in studied patients.

RESULTS

Both physical and mental dimensions of SF-36, pain, functional, and stiffness subscales of WOMAC and both functional and clinical scores of KSS improved significantly after revision TKA (p<0.001). In the multivariate analysis, male gender, a lower Charlson comorbidity index, and higher preoperative functional KSS were predictors of higher functional KSS at 2 years after revision. Lower preoperative pain and higher clinical KSS were predictors of better outcome as measured by pain scale of WOMAC. Body mass index (BMI) and preoperative clinical KSS were significant predictors of function and stiffness as measured by WOMAC.

CONCLUSIONS

BMI is a modifiable predictor of functional outcome after revision TKA. Moreover, patients with higher preoperative functional scores appear to have better postoperative function.

LEVEL OF EVIDENCE

Level II.

Revision total knee arthroplasty for septic versus aseptic failure

PURPOSE

To compare the medium-term outcome of revision total knee arthroplasty (TKA) for septic versus aseptic failure.

METHODS

Records of 142 patients who underwent revision TKA by a single senior surgeon for septic (n=65) or aseptic (n=77) failure were reviewed. In the septic group, 67 knees in 42 women and 23 men were included. In the aseptic group, 88 knees in 51 women and 26 men were included. The Knee Society Score was measured. The Kaplan Meier survival curve at months 36, 60, and 95 was plotted, with revision as the end point. The survival rates at each specific time point between the 2 groups were compared using the Z test.

RESULTS

The Knee Society Scores improved 18% from 51 to 69 in the septic group and 18% from 52 to 70 in the aseptic group (p=0.72). The range of motion improved 30% from 72 to 102 degrees in the septic group and 39% from 62 to 100 degrees in the aseptic group (p<0.001).

CONCLUSION

Results of the 2 groups were similar in terms of the Knee Society Score, range of motion, and the Kaplan-Meier survivorship.

Periprosthetic knee infection: ten strategies that work

Periprosthetic joint infection (PJI) is one of the most serious complications following total knee arthroplasty (TKA). The demand for TKA is rapidly increasing, resulting in a subsequent increase in infections involving knee prosthesis. Despite the existence of common management practices, the best approach for several aspects in the management of periprosthetic knee infection remains controversial. This review examines the current understanding in the management of the following aspects of PJI: preoperative risk stratification, preoperative antibiotics, preoperative skin preparation, outpatient diagnosis, assessing for infection in revision cases, improving culture utility, irrigation and debridement, one and two-stage revision, and patient prognostic information. Moreover, ten strategies for the management of periprosthetic knee infection based on available literature, and experience of the authors were reviewed.

Reason for revision TKA predicts clinical outcome: prospective evaluation of 150 consecutive patients with 2-years followup

BACKGROUND

There is limited knowledge regarding the relationship between the reason for revising a TKA and the clinical outcome in terms of satisfaction, pain, and function with time.

QUESTIONS/PURPOSES

In a cohort of patients receiving a fully revised TKA, we hypothesized (1) outcomes would differ according to reason for revision at 2 years, (2) outcomes would improve gradually during those 2 years, (3) rates of complications differ depending on the reason for revision, and (4) patients with complications have lower scores.

METHODS

We studied a prospective cohort of 150 patients receiving a fully revised TKA using a single implant system in two high-volume centers at 24 months of followup. VAS satisfaction, VAS pain, The Knee Society Scoring System(©) (KSS) clinical and functional scores, and complication rate were correlated with their reasons for revision, including septic loosening, aseptic loosening, component malposition, instability, and stiffness.

RESULTS

The aseptic loosening group showed better outcomes compared with the instability, malposition, and septic loosening groups, which showed intermediate results (p < 0.05). The stiffness group performed significantly worse on all outcome measures. The outcome for patients with a complication, after treatment of the complication, was less favorable.

CONCLUSIONS

The reason for revision TKA predicts clinical outcomes. Satisfaction, pain reduction, and functional improvement are better and complication rates are lower after revision TKA for aseptic loosening than for other causes of failure. For component malposition, instability, and septic loosening groups, there may be more pain and a higher complication rate. For stiffness, the outcomes are less favorable in all scores.

LEVEL OF EVIDENCE

Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Success after treatment of periprosthetic joint infection: a Delphi-based international multidisciplinary consensus

BACKGROUND

The lack of agreement regarding what constitutes successful treatment for periprosthetic joint infections (PJI) makes it difficult to compare the different strategies of management that are used in clinical practice and in research studies.

QUESTIONS/PURPOSES

The aims of this study were to create a consensus definition for success after PJI treatment, and to provide a universal, multidimensional framework for reporting of studies regarding PJI treatment.

METHODS

A two-round basic Delphi method was used to reach a consensus definition. We invited 159 international experts (orthopaedic surgeons, infectious disease specialists, and clinical researchers) from 17 countries to participate; 59 participated in the first round, and 42 participated in the second round. The final definition consisted of all statements that achieved strong agreement (80% or greater of participants considering a criterion relevant for defining success).

RESULTS

The consensus definition of a successfully treated PJI is: (1) infection eradication, characterized by a healed wound without fistula, drainage, or pain, and no infection recurrence caused by the same organism strain; (2) no subsequent surgical intervention for infection after reimplantation surgery; and (3) no occurrence of PJI-related mortality (by causes such as sepsis, necrotizing fasciitis). The Delphi panel agreed to defining midterm results as those reported 5 or more years after the definitive PJI surgery, and long-term results as those reported 10 or more years after surgery. Although no consensus was reached on the definition of short-term results, 71% of the participants agreed that 2 years after the definitive PJI surgery is acceptable to define it.

CONCLUSIONS

This multidimensional definition of success after PJI treatment may be used to report and compare results of treatment of this catastrophic complication.

LEVEL OF EVIDENCE

Level V, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Revision Total Knee Arthroplasty: Causes and Outcomes

Introduction: Local data on revision total knee arthroplasty (TKA) are limited. This study aims to assess the causes and outcomes of revision TKA in a single institution, with a 2-year follow-up. Materials and Methods: A retrospective review of case records of patients who underwent revision TKA in 2008 and 2009 in the authors’ institution was performed. Outcome was assessed using SF-36, Oxford knee score and Knee Society Clinical Rating System preoperatively, at 6 months and at 2 years’ follow-up. Results: Forty-one patients (41 knees) were included in the study. Indications for revision were aseptic loosening in 13 (31.7%), mechanical wear/component failure in 10 (24.4%), infection in 9 (22.0%), malalignment in 4 (9.8%), instability in 3 (7.3%), periprosthetic fracture in 1 (2.4%) and persistent stiffness in 1 (2.4%). Significant improvements were seen postoperatively in all 3 instruments used to evaluate clinical outcome. These improvements were seen at 6 months after surgery, and were maintained through the 2-year follow-up period. There were no significant changes in all scores between 6 months and 2 years follow-up. There was 100% survivorship of the implants with no postoperative complications requiring surgical intervention. Conclusion: Indications for revision TKA locally are similar to those in other large centres. Revision total knee arthroplasty results in significantly improved function and quality of life for patients, which is maintained over a 2-year follow-up period. In our series, we obtained 100% implant survivorship. Key words: Failure, Infection, Instability, Loosening, Malalignment

The aetiology of total knee arthroplasty failure influences the improvement in knee function

BACKGROUND

Some indications for revision total knee arthroplasty (TKA), e.g. arthrofibrosis, have been identified to yield inferior results. The aim of this study was to analyse the results of revision TKA according to aetiology of TKA failure.

PATIENTS AND METHODS

The results of 97 consecutive revision TKA in 97 patients stratified according to the aetiology of primary TKA failure (periprosthetic infection, aseptic loosening, instability and arthrofibrosis), were compared using the Knee Society Score (KSS). The effect of patient age, gender, BMI, American Society of Anesthesiologists (ASA) classification, interval to revision and the occurrence of complications on the outcome were also analysed.

RESULTS

After a mean follow-up of 29 months, the KSS had significantly improved in all patient groups (p < 0.001). The analysis of variance among patient groups depicted no significant differences between preoperative KSS (p = 0.618) and postoperative KSS (p = 0.915), while the magnitude of pre- to postoperative improvement showed significant differences between the groups (p = 0.006). The aetiology of primary TKA failure had an independent influence on pre- to postoperative improvement (p = 0.014). Of the other factors analysed, only the ASA classification had an independent impact on postoperative KSS (p = 0.045).

CONCLUSION

The aetiology of TKA failure has an effect on the improvement in knee function from revision TKA. As no difference was observed between patient groups postoperatively, similar clinical results can be expected independent of the aetiology of primary TKA failure.

Minimum Two-year Results of Revision Total Knee Arthroplasty Following Infectious or Non-infectious Causes

Purpose

To compare clinical outcome of revision total knee arthroplasty (TKA) between the infected and non-infected groups.

Materials and Methods

This study compared the clinical and radiographic results of 21 infected and 15 non-infected revision TKAs at a minimum 2-years follow-up. Clinical evaluations were assessed using the range of motion (ROM), Hospital for Special Surgery (HSS) score, Knee Society Knee Score (KSKS), Knee Society Function Score (KSFS), and Western Ontario and McMaster Universities (WOMAC) score. Radiologic evaluations were assessed using the radiographic results of the American Knee Society and joint line change.

Results

Patients operated for non-infectious causes had significantly better postoperative ROM than the infected group (infected group, 101.7°; non-infected group, 117.8°). The infected group achieved significantly poor HSS (79.2 vs. 85.5), KSKS (75.5 vs. 86.6), KSFS (76.9 vs. 85.5), WOMAC (30.3 vs. 21.2) scores than the non-infected group. Postoperative joint line elevation was lower in the infected versus non-infected group (0.5 mm vs. 2.1 mm), but there was no significant difference.

Conclusions

Revision TKA is an effective treatment that can provide successful results in the infected as well as non-infected patients. The overall results of non-infected revision were more satisfactory than infected revision.

Functional outcome following aseptic single-stage revision knee arthroplasty

PURPOSE

This study attempts to quantify the influence of constraint and various indications upon functional outcome following aseptic first-time revision knee arthroplasty.

METHODS

A single-centre prospective study was performed to examine the outcome for 175 consecutive total revision knee replacements performed between 2003 and 2008 with a minimum follow-up of 2 years. Patient-reported outcome data were used to determine the influence of final level of component constraint, its relationship with primary indication for surgery and the predictor variable for functional outcome at 1 year.

RESULTS

All patients were found to have a significant improvement for WOMAC pain, function and stiffness score and physical functioning, role physical, bodily pain and social functioning components of SF-36 score. About 69% were satisfied with the overall procedure. WOMAC function, pain and stiffness score was significantly worse for patients revised for instability (27%) compared to that for aseptic loosening (46%). A significantly higher proportion of patients were satisfied with the procedure, had a better quality of life and would have the surgery again in the aseptic loosening group as compared to the instability group. Revision to a higher level of constraint did not improve knee function irrespective of the primary indication for surgery.

CONCLUSION

This study has found that revision for instability, irrespective of choice of new device, was met with significantly poorer functional outcome. The level of constraint did not influence functional outcome.

LEVEL OF EVIDENCE

II.

Causes of a painful total knee arthroplasty. Are patients still receiving total knee arthroplasty for extrinsic pathologies?

PURPOSE

Whilst patients undergoing total knee replacements generally have good relief of their symptoms, up to 20% complain of persisting pain. Revision rates have therefore been rising, particularly so for unexplained pain. We reviewed the causes of painful total knee replacements including extrinsic causes.

METHODS

Forty-five consecutive patients referred to our department with painful total knee replacement were reviewed with our standard protocol, including history and examination, inflammatory markers and radiological studies including radiographs of the hip and knee and computed tomography scan of the knee joint.

RESULTS

Of the 45 patients, 15 patients had degenerative hip and lumbar spine disease which resolved after injections of the relevant joints. Nine patients had unexplained pain.

CONCLUSIONS

Patients may still be undergoing knee arthroplasty for degenerative lumbar spine and hip osteoarthritis. We suggest heightened awareness at pre- and post-operative assessment and thorough history and examination with the use of diagnostic injections to identify the cause of pain if there is doubt.

Septic versus aseptic hip revision: how different?

Background

The few available studies directly comparing aseptic and septic joint revision surgery report conflicting results. We investigated whether two-stage revision of septic hip prosthesis with a preformed antibiotic-loaded spacer and an uncemented prosthesis provides hip function and quality of life similar to those provided by aseptic revision surgery in the medium term, as well as the associated direct hospital costs.

Materials and methods

We prospectively evaluated the hip function (Harris hip score) and quality of life (WOMAC and SF-12 scores) of 80 patients who underwent one-stage revision for aseptic loosening (Group A, 40 patients) or two-stage revision for septic total hip prostheses (Group S, 40 patients). Patients were matched for gender, age, and bone loss. A preformed antibiotic-loaded cement spacer was used for two-stage revision, and uncemented modular prostheses were implanted at revision in both groups. The minimum follow-up was 2 years (average 4 years; range 2–6 years).

Results

We found no difference in infection recurrence or aseptic loosening rate in the two groups. Average Harris hip score increased similarly in both groups: from 19.1 to 74.0 in Group A versus 15.0–71.2 in Group S. Patient-reported quality-of-life questionnaires (SF-12 and WOMAC) at last follow-up were similar postoperatively, but the complication rate for Group S was twice that of Group A (20.8 versus 10%). Mean overall hospital-related costs of two-stage procedures were 2.2 times greater than those for aseptic revisions.

Conclusions

Two-stage revision for infected hip prostheses, using a preformed antibiotic-loaded cement spacer and uncemented revision prosthesis, offers a success rate comparable to noninfected revisions in the medium term but is associated with a higher complication rate and costs.