Risk factors for revision due to prosthetic joint infection following total knee arthroplasty based on 62,087 knees in the Finnish Arthroplasty Register from 2014 to 2020.

BACKGROUND AND PURPOSE: Periprosthetic joint infection (PJI) is the commonest reason for revision after total knee arthroplasty (TKA). We assessed the risk factors for revision due to PJI following TKA based on the Finnish Arthroplasty Register (FAR). PATIENTS AND METHODS: We analyzed 62,087 primary condylar TKAs registered between June 2014 and February 2020 with revision for PJI as the endpoint. Cox proportional hazards regression was used to estimate hazard ratios (HR) with 95% confidence intervals (CI) for the first PJI revision using 25 potential patient- and surgical-related risk factors as covariates. RESULTS: 484 knees were revised for the first time during the first postoperative year because of PJI. The HRs for revision due to PJI in unadjusted analysis were 0.5 (0.4-0.6) for female sex, 0.7 (0.6-1.0) for BMI 25-29, and 1.6 (1.1-2.5) for BMI > 40 compared with BMI < 25, 4.0 (1.3-12) for preoperative fracture diagnosis compared with osteoarthritis, and 0.7 (0.5-0.9) for use of an antimicrobial incise drape. In adjusted analysis the HRs were 2.2 (1.4-3.5) for ASA class III-IV compared with class I, 1.7 (1.4-2.1) for intraoperative bleeding ≥ 100 mL, 1.4 (1.2-1.8) for use of a drain, 0.7 (0.5-1.0) for short duration of operation of 45-59 minutes, and 1.7 (1.3-2.3) for long operation duration > 120 min compared with 60-89 minutes, and 1.3 (1.0-1.8) for use of general anesthesia. CONCLUSION: We found increased risk for revision due to PJI when no incise drape was used. The use of drainage also increased the risk. Specializing in performing TKA reduces operative time and thereby also the PJI rate.

No difference in implant survival between 28-mm M2a RingLoc metal-on-metal and metal-on-polyethylene total hip arthroplasty: results from the Finnish Arthroplasty Register.

BACKGROUND AND PURPOSE: Long-term outcome of small head (28 mm) metal-on-metal (MoM) total hip arthroplasty (THA) is available mainly for Metasul devices (Sulzer Medica, Winterthur, Switzerland). Biomet MoM THA was frequently used in Finland. Therefore, we assessed long-term survivorship of the M2a 28-mm RingLoc MoM THA (Biomet, Warsaw, IN, USA) and compared it with the metal-on-polyethylene (MoP) RingLoc THA from the same manufacturer. PATIENTS AND METHODS: We conducted a register study based on THAs from the Finnish Arthroplasty Register performed between January 1, 2000 and December 31, 2007. 290 28-mm head M2a MoM THAs and 1,647 28-mm head MoP THAs (reference group) were included. The endpoint was revision for any reason, or revision for aseptic loosening, osteolysis, liner wear, or metallosis as one group. Kaplan-Meier survival estimates were calculated, and revision risks were assessed using a Cox multiple regression model, both with 95% confidence intervals (CI). RESULTS: No difference was found in the 15-year Kaplan-Meier survivorship between the 28-mm head M2a RingLoc MoM THA and the reference group for any reason for revision (87.7% [82.9-92.1] and 83.3% [81.0-85.3], respectively). The adjusted hazard ratio (HR) for any reason for revision for the MoM THA group compared with the reference group was at least equal or better (0.70 [0.48-1.02]). Both groups presented similar survival for revision for aseptic loosening of the cup, osteolysis, liner wear, or metallosis, at 96.2% (92.7-98.0) and 95.4% (93.9-96.5), respectively. INTERPRETATION: In the long-term survival there was no difference between the M2a 28-mm RingLoc MoM THA and 28-mm MoP THA. Further follow-up regimens for M2a 28-mm RingLoc THA patients may be unnecessary, but long-term metal ion and radiological data is needed before any formal suggestions.

The effects and safety of telerehabilitation in patients with lower-limb joint replacement: A systematic review and narrative synthesis.

INTRODUCTION: As the number of patients undergoing primary lower-limb joint replacement has risen continuously, hospital-based healthcare resources have become limited. Delivery of any ongoing rehabilitation needs to adapt to this trend. This systematic literature aimed to examine the effects and safety of telerehabilitation in patients with lower-limb joint replacement. METHODS: A systematic review of randomized controlled trials was conducted according to procedures by the Joanna Briggs Institute. Studies published prior to February 2020 were identified from Medline Ovid, Scopus, Ebsco Databases and Web of Science. Reference lists of relevant studies were also manually checked to find additional studies. Two researchers conducted study selection separately. The Joanna Briggs Institute Critical Appraisal Checklist for Randomized Controlled Trials was used to evaluate the quality of the relevant studies published. A narrative synthesis was used to report the results whereas effect sizes were estimated for different outcomes. RESULTS: Nine studies with 1266 patients were included. Study quality was predominantly affected by the lack of blinding. The patients who completed telerehabilitation showed an improvement in physical functioning that was similar to that of patients completing conventional in-person outpatient physical therapy without an increase in adverse events or resource utilization. The effect of telerehabilitation on physical functioning, however, was assessed as heterogeneous and moderate- to low-quality evidence. DISCUSSION: Telerehabilitation is a practical alternative to conventional in-person outpatient physical therapy in patients with lower-limb joint replacement. However, more robust studies are needed to build evidence about telerehabilitation.

Risk factors for prosthetic joint infections following total hip arthroplasty based on 33,337 hips in the Finnish Arthroplasty Register from 2014 to 2018.

Background and purpose - Periprosthetic joint infection (PJI) is a devastating complication and more information on risk factors for PJI is required to find measures to prevent infections. Therefore, we assessed risk factors for PJI after primary total hip arthroplasty (THA) in a large patient cohort.Patients and methods - We analyzed 33,337 primary THAs performed between May 2014 and January 2018 based on the Finnish Arthroplasty Register (FAR). Cox proportional hazards regression was used to estimate hazard ratios with 95% confidence intervals (CI) for first PJI revision operation using 25 potential patient- and surgical-related risk factors as covariates.Results - 350 primary THAs were revised for the first time due to PJI during the study period. The hazard ratios for PJI revision in multivariable analysis were 2.0 (CI 1.3-3.2) for ASA class II and 3.2 (2.0-5.1) for ASA class III-IV compared with ASA class I, 1.4 (1.1-1.7) for bleeding > 500 mL compared with < 500 mL, 0.4 (0.2-0.7) for ceramic-on-ceramic bearing couple compared with metal-on-polyethylene and for the first 3 postoperative weeks, 3.0 (1.6-5.6) for operation time of > 120 minutes compared with 45-59 minutes, and 2.6 (1.4-4.9) for simultaneous bilateral operation. In the univariable analysis, hazard ratios for PJI revision were 2.3 (1.7-3.3) for BMI of 31-35 and 5.0 (3.5-7.1) for BMI of > 35 compared with patients with BMI of 21-25.Interpretation - We found several modifiable risk factors associated with increased PJI revision risk after THA to which special attention should be paid preoperatively. In particular, high BMI may be an even more prominent risk factor for PJI than previously assessed.

Preoperative Risk Prediction Models for Short-Term Revision and Death After Total Hip Arthroplasty: Data from the Finnish Arthroplasty Register.

Because of the increasing number of total hip arthroplasties (THAs), even a small proportion of complications after the operation can lead to substantial individual difficulties and health-care costs. The aim of this study was to develop simple-to-use risk prediction models to assess the risk of the most common reasons for implant failure to facilitate clinical decision-making and to ensure long-term survival of primary THAs. METHODS: We analyzed patient and surgical data reported to the Finnish Arthroplasty Register (FAR) on 25,919 primary THAs performed in Finland between May 2014 and January 2018. For the most frequent adverse outcomes after primary THA, we developed multivariable Lasso regression models based on the data of the randomly selected training cohort (two-thirds of the data). The performances of all models were validated using the remaining, independent test set consisting of 8,640 primary THAs (one-third of the data) not used for building the models. RESULTS: The most common outcomes within 6 months after the primary THA were revision operations due to periprosthetic joint infection (1.1%), dislocation (0.7%), or periprosthetic fracture (0.5%), and death (0.7%). For each of these outcomes, Lasso regression identified subsets of variables required for accurate risk predictions. The highest discrimination performance, in terms of area under the receiver operating characteristic curve (AUROC), was observed for death (0.84), whereas the performance was lower for revisions due to periprosthetic joint infection (0.68), dislocation (0.64), or periprosthetic fracture (0.65). CONCLUSIONS: Based on the small number of preoperative characteristics of the patient and modifiable surgical parameters, the developed risk prediction models can be easily used to assess the risk of revision or death. All developed models hold the potential to aid clinical decision-making, ultimately leading to improved clinical outcomes. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Implant survival of 2,723 vitamin E-infused highly crosslinked polyethylene liners in total hip arthroplasty: data from the Finnish Arthroplasty Register.

Background and purpose - The use of crosslinked polyethylene in total hip arthroplasty (THA) has decreased wear remarkably. It has been suggested that the antioxidative effects of vitamin E may enhance the wear properties of polyethylene even further. This study evaluates revision rates between vitamin E-infused polyethylene liners (E1 and E-poly, ZimmerBiomet, Warsaw, IN, USA) versus moderately crosslinked polyethylene (ModXLPE) liners from the same manufacturer used in primary THA.Patients and methods - We conducted a study based on data from the Finnish Arthroplasty Register. The study group consisted of 2,723 THAs with a vitamin E-infused liner and a reference group of 2,707 THAs with a moderately crosslinked polyethylene liner. Survivorship, revision risk, and re-revision causes were compared between groups.Results - The 7-year survival of the vitamin E-infused polyethylene liner group and of the reference group with revision for any reason as the endpoint was comparable (94% [95% CI 92.9-94.9] and 93% [CI 91.9-93.9], respectively). The adjusted hazard ratio (HR) for any revision was similar between the groups (0.7 [CI 0.4-1.1]). When revision for aseptic loosening was studied as the endpoint, the survival for the study group was 99% (CI 98.6-99.4) and for the reference group 99% (CI 98.7-99.5), and the risk of revision was comparable between the study groups (HR 1.3 [CI 0.7-2.5]).Interpretation - After an observation period of 7 years vitamin E-infused liners shows results equal to results obtained with crosslinked polyethylene liners.

Implant Survival of 6,080 Tritanium Cups in Primary Total Hip Arthroplasty: Data from the Finnish Arthroplasty Register from 2009 to 2017.

BACKGROUND: To enhance osseointegration in total hip arthroplasty (THA), ultraporous or highly porous-coated cups were introduced. Implant survival data on these new devices have been scarce. The aim of our study was to assess the survivorship of ultraporous Tritanium cups (Stryker) in a population-based register study. METHODS: In this study, we collected data on 6,080 primary THAs using a Tritanium cup and 25,670 THAs using a conventional cup (control group) from the Finnish Arthroplasty Register; these procedures were performed from January 1, 2009, to December 31, 2017. We calculated the Kaplan-Meier survival estimates with 95% confidence intervals (CIs). The end point was revision for any reason or for aseptic loosening of the cup. The revision risks were assessed with use of the Cox multiple regression model. The variables assessed in the Cox model were femoral head size, age group, involved side, operation year, sex, diagnosis, and fixation of the stem. The proportional hazards assumption of the Cox model was not fulfilled, so the follow-up time was divided into 3 time periods: 0 to 2 years, >2 to 4 years, and >4 years. RESULTS: When comparing the 2 groups with regard to revision for any reason, the 5-year Kaplan-Meier survivorship of the Tritanium group (94.7% [95% CI, 94.0% to 95.4%]) was inferior to that of the control group (96.0% [95% CI, 95.7% to 96.3%]). In the Cox regression analysis of the 2 groups for the time period of >4 years, the Tritanium group had an increased risk of revision for any reason compared with the control group (hazard ratio [HR], 3.12 [95% CI, 1.82 to 5.35]; p < 0.001). With regard to revision for aseptic loosening of the cup, the Tritanium group had an increased risk of revision compared with the control group for both 0 to 2 years (HR, 3.80 [95% CI, 1.76 to 8.24]; p < 0.001) and >2 to 4 years (HR, 11.2 [95% CI, 3.28 to 38.0]; p < 0.001). CONCLUSIONS: There was no advantage to using the ultraporous-coated Tritanium cup for primary THA compared with conventional uncemented cups. However, wide CIs for some HR estimates may point to a lack of precision. Therefore, further research on subject is needed. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

The digital patient journey solution for patients undergoing elective hip and knee arthroplasty: Protocol for a pragmatic randomized controlled trial.

AIM: To describe a randomized controlled trial (RCT) protocol that will evaluate the effectiveness of a digital patient journey (DPJ) solution in improving the outcomes of patients undergoing total hip and knee arthroplasty. BACKGROUND: There is an urgent need for novel technologies to ensure sustainability, improve patient experience, and empower patients in their own care by providing information, support, and control. DESIGN: A pragmatic RCT with two parallel arms. METHODS: The participants randomized assigned to the intervention arm (N = 33) will receive access to the DPJ solution. The participants in the control arm (N = 33) will receive conventional care, which is provided face to face by using paper-based methods. The group allocations will be blinded from the study nurse during the recruitment and baseline measures, as well as from the outcome assessors. Patients with total hip arthroplasty will be followed up for 8-12 weeks, whereas patients with total knee arthroplasty will be followed up for 6-8 weeks. The primary outcome is health-related quality of life, measured by the EuroQol EQ-5D-5L scale. Secondary outcomes include functional recovery, pain, patient experience, and self-efficacy. The first results are expected to be submitted for publication in 2020. IMPACT: This study will provide information on the health effects and cost benefits of using the DPJ solution to support a patient's preparation for surgery and postdischarge surgical care. If the DPJ solution is found to be effective, its implementation into clinical practice could lead to further improvements in patient outcomes. If the DPJ solution is found to be cost effective for the hospital, it could be used to improve hospital resource efficiency.

Implant Survival of Constrained Acetabular Device in Primary Total Hip Arthroplasty Based on Data From the Finnish Arthroplasty Register.

BACKGROUND: Constrained acetabular devices were developed to prevent dislocations after total hip arthroplasty (THA). However, the data on their success have been contradictory. In this study, we aimed to assess implant survival of the constrained acetabular device in primary THA based on the Finnish Arthroplasty Register data. METHODS: A total of 373 primary THAs with constrained acetabular devices inserted from 2006 to 2017 were included. A reference group was formed on a 1:3 basis and matched for age, sex, and diagnosis, consisting of 1118 conventional THAs. Implant survival estimates using death as a competing risk were assessed with revision for any reason and for any aseptic reason as the endpoints. The Cox multiple regression models were adjusted for age, sex, and diagnosis. The mean follow-up time was 3.3 (0-12.4) years for the constrained device group and 3.8 (0-12.0) years for the reference group. RESULTS: Overall, there were 21 revisions in the constrained device group and 49 in the reference group. The 8-year survivorship for any reason was 94% (confidence interval [CI]: 91-96) for the constrained device group and 93% (CI: 89-97) for the reference group. With revision for any aseptic reason as the endpoint, the 8-year survivorships were 97% (CI: 95-99) and 94% (CI: 90-98), respectively. During the first 1.5 years, the constrained acetabular device group had a similar revision risk (hazard ratio: 1.09 [CI: 0.57-2.07], P = .8) to that of the reference group. CONCLUSION: The constrained acetabular device had good survival in primary THA, and our results support its continued use even in high-risk patients.

Patients' satisfaction and experiences during elective primary fast-track total hip and knee arthroplasty journey: A qualitative study.

AIMS AND OBJECTIVES: To explore how satisfied patients are with the process of treatment and care and to identify the experiences that patients perceive during elective primary fast-track total hip and knee arthroplasty journey. BACKGROUND: Greater satisfaction with care has predicted better quality of recovery, and patient experience has been positively associated with patient safety and clinical effectiveness. However, a little is still known about how patients experience their treatment and care. DESIGN: A qualitative interview study. METHODS: The study was conducted among 20 patients in a single joint replacement centre during 2018. Patient satisfaction was measured using a numerical rating scale. Patients' experiences were identified through qualitative semi-structured interviews which were analysed using an inductive content analysis method. The COREQ checklist was used (Supporting Information). RESULTS: The mean numerical rating scale score for overall satisfaction was 9.0 (SD 1.1) on a scale from 0-10. The patients' experiences were grouped under eight main categories that were derived from the qualitative data in the analysis: (a) patient selection, (b) meeting the Health Care Guarantee, (c) patient flow, (d) postdischarge care, (e) patient counselling, (f) transparency of the journey, (g) communication and (h) feedback. CONCLUSIONS: The findings suggest that patients are highly satisfied after an elective primary fast-track total hip and knee arthroplasty. However, closer analysis of the patients' experiences reveals challenges and suggestions on how they could be solved, often involving digital technologies. RELEVANCE TO CLINICAL PRACTICE: As the number of total joint arthroplasties grows, patients and their families need to take ever greater responsibility, for their own care from advance preparation to rehabilitation. The findings of the study can be used to organise work, improving patient-clinical communication, fostering engagement and improving patient centredness. In addition, the results pinpoint the issues on how the patient experience could be improved.

Healthcare professionals' perceived problems in fast-track hip and knee arthroplasty: results of a qualitative interview study.

BACKGROUND: Fast-track and outpatient arthroplasty methodologies combine evidence-based clinical features with organizational optimization resulting in a streamlined pathway from admission to discharge and beyond. This qualitative study explored perceived problems of healthcare professionals during fast-track hip and knee arthroplasty. METHODS: Semi-structured interviews were conducted with four surgeons, two anesthesiologists, ten nurses, and four physiotherapists. An inductive content analysis was used to analyze the data. NVivo qualitative data analysis software was used. RESULTS: Analysis of the data revealed eight main categories of problems: patient selection, referrals, meeting the Health Care Guarantee, patient flow, homecare, patient counseling, transparency of the journey, and receiving feedback. In addition, problems related to information flows and communication, responsibilities between different stakeholders, and existing information systems were identified. CONCLUSIONS: The study revealed that healthcare professionals perceived several problems during the fast-track journey that reduce its effectiveness and make it more difficult to meet the Health Care Guarantee. Problems could be alleviated by changing internal and external organizational practices, as well as by developing new information and communication technologies that would provide up-to-date communication channels for healthcare professionals and patients. In addition, new collaboration mechanisms should be developed in order to solve the problems that occur across different organizations.

Healthcare professionals' proposed eHealth needs in elective primary fast-track hip and knee arthroplasty journey: A qualitative interview study.

AIMS AND OBJECTIVES: To examine the lived experience of healthcare professionals providing care for patients with total hip and knee arthroplasty and to understand healthcare professionals' proposed eHealth needs in elective primary fast-track hip and knee arthroplasty journey. BACKGROUND: There is little evidence in nursing literature to indicate how to develop new eHealth services to support surgical care journeys. Evidence is particularly lacking regarding the development of eHealth solutions. DESIGN: This was a qualitative interview study. METHODS: Semi-structured interviews were conducted with four surgeons, two anaesthesiologists, ten nurses and four physiotherapists in a single joint replacement centre during autumn 2018. The data were analysed using an inductive content analysis method. NVivo qualitative data analysis software was used. The COREQ checklist for qualitative studies was followed. RESULTS: Our research addressed the gap in evidence by focusing on the four main parts of the patient journey in the selected context. Analysis of the data revealed nine main categories for the proposed eHealth needs: eligibility criteria, referrals, meeting the Health Care Guarantee, patient flow, postdischarge care, patient counselling, communication, transparency of the journey and receiving feedback. In addition, the requirements and further development needs for eHealth solutions were generally identified. CONCLUSIONS: From the point of view of healthcare professionals, eHealth solutions have huge potential in supporting the elective primary fast-track hip and knee arthroplasty journey. However, it is important to acknowledge that these needs may be very different depending on the technological and organisational environment in question. RELEVANCE TO CLINICAL PRACTICE: More effective use of information and communication technologies is needed for organisational optimisation resulting in a streamlined pathway, better access to healthcare services, improved outcomes and an improved patient experience. These results can be used in the development of new eHealth solutions to support surgical care journeys and patient education.

Short-term survival of cementless Oxford unicondylar knee arthroplasty based on the Finnish Arthroplasty Register.

BACKGROUND: Cementless unicondylar knee arthroplasty (UKA) was introduced to secure long-term fixation and reduce the risk of revision. Experience with cementless UKA fixation is limited. METHODS: The short-term survival (up to five years) of cementless Oxford UKA was assessed using data from the Finish Arthroplasty Register and was compared with that of cemented Oxford 3 UKA and total knee arthroplasty (TKA). Datawere obtained, from the Finnish Arthroplasty Register, on 1076 cementless Oxford UKAs and 2279 cemented Oxford 3 UKAs performed for primary osteoarthritis in 2005-2015. The Kaplan-Meier method, with revision for any reason as the endpoint, was used to assess the survival of these two UKA groups, and the results were compared with that of 65,563 cemented TKAs treated for primary osteoarthritis over the same period. The risk of revision of both Oxford prostheses was compared using Cox regression model, with adjustment for age and sex, with the cemented TKA group as reference. RESULTS: The three-year survival was 93.7% for the cementless Oxford, 92.2% for the cemented Oxford 3, and 97.3% for the cemented TKA. The corresponding figures at five years were 92.3%, 88.9%, and 96.6%, respectively. The revision rate for both the cementless Oxford and the cemented Oxford 3 was significantly increased when compared with the cemented TKA (P < 0.001). CONCLUSIONS: The survival of the cementless Oxford method was higher than that of the cemented Oxford 3 in the short term. The overall survival of Oxford UKA was poor in comparison with contemporary TKAs.

Infection triples the cost of a primary joint arthroplasty.

BACKGROUND: In Europe few studies have analyzed the costs of treating aseptic revisions and prosthetic joint infections with either debridement, antibiotics and implant retention or two-stage revision, as compared to the cost of a primary total joint arthroplasty. METHODS: The purpose was to analyze the costs of total joint arthroplasties, aseptic revisions and prosthetic joint infections treated with debridement, antibiotics and implant retention or a two-stage revision. We conducted a retrospective cohort study of patients who had a total joint arthroplasty in the Oulu University Hospital during the three-year period from 2013 to 2015. The costs were divided to specific services (e.g. procedure costs, ward care costs, laboratory). Actual costs obtained from the hospital's financial database were used for analysis. RESULTS: There were 1708 total joint arthroplasties without complications, 18 aseptic revisions and 42 prosthetic joint infections eligible for analysis. The mean cost of a total joint arthroplasty was €7200, the excess cost of an aseptic revision was €10,900 and the excess cost of a prosthetic joint infection was €18,900 (total joint arthroplasty vs. infection, p < .0001). The excess cost was €12,800 for debridement, antibiotics and implant retention treatment and €44,600 for a two-stage revision (p < .0001). The two most expensive services were ward care and procedures. CONCLUSIONS: Infection tripled the cost of a total joint arthroplasty. The cost of two-stage revisions were triple that of debridement, antibiotics and implant retention treatment.

Survival of 11,390 Continuum cups in primary total hip arthroplasty based on data from the Finnish Arthroplasty Register.

Background and purpose - The use of trabecular metal (TM) cups for primary total hip arthroplasty (THA) is increasing. Some recent data suggest that the use of TM in primary THA might be associated with an increased risk of revision. We compared implant survival of Continuum acetabular cups with other commonly used uncemented cups. Patients and methods - Data on 11,390 primary THAs with the Continuum cup and 30,372 THAs with other uncemented cups (reference group) were collected from the Finnish Arthroplasty Register. Kaplan-Meier survival estimates were calculated; the endpoint was revision for any reason, for infection, or for dislocation. Revision risks were assessed with adjusted Cox multiple regression models. A subgroup analysis on the use of neutral or elevated liners in the Continuum group was made. Results - The 7-year survivorship of the Continuum group was 94.6% (95% CI 94.0-95.2) versus 95.6% (CI 95.3-95.8) in the reference group for revision for any reason. The risk for revision was higher in the Continuum group than in the reference group both for revision for any reason (HR 1.3 [CI 1.2-1.5)]) and for revision for dislocation (HR 1.9 [CI 1.5-2.3]). There was no difference in the rates of revision because of infection (HR 0.99 [CI 0.78-1.3]). Use of a neutral liner increased the risk for revision due to dislocation in comparison with the use of an elevated rim liner in the Continuum group (HR 1.7 [CI 1.2-2.5]). Interpretation - THA with Continuum cups is associated with an increased risk of revision compared with other uncemented cups, mainly due to revisions because of dislocation. Our results support the use of an elevated liner when Continuum cups are used for primary THA.

High Revision Rate for Large-head Metal-on-metal THA at a Mean of 7.1 Years: A Registry Study.

BACKGROUND: Large-diameter head metal-on-metal (MoM) THA has largely been abandoned as a result of higher than anticipated revision rates. However, the majority of these implants are still in situ. Although earlier reports from the Finnish Arthroplasty Register noted similar short-term survivorship between large-diameter head MoM THA and conventional cemented THA, longer term survivorship of this population is unclear. Although reported revision rates for this implant group have been high, the majority of these implants have not been revised and followup is important to improve long-term management. QUESTIONS/PURPOSES: The purposes of this study were (1) to compare the 10-year competing risk survivorship of large-diameter head MoM THA with the survivorship of conventional THA in the Finnish Arthroplasty Register; (2) to report the large-diameter head MoM THA survival at the manufacturer/brand level; and (3) to identify the most common reasons for revision of large-diameter head MoM THA in the Finnish Arthroplasty Register. METHODS: The six most commonly used large-diameter head (≥ 38 mm) MoM THA devices in Finland between years 2004 and 2013 were selected (n = 10,959 implants). The completeness of the Finnish Registry is > 95% in primary THA and patients are censored from the date of death or at the point of emigration; followup continued until the end of 2015. The conventional THA control group consisted of the two most frequently used devices (Vision/Bimetric and ABG II/ABG II) with metal-on-polyethylene or ceramic-on-ceramic bearing surfaces implanted between 2002 and 2013 (n = 5177). The study group was formed by selecting all pairs of large-diameter head MoM and reference THA protheses within the same age group ( < 49, 50-54, 55-59, 60-64, 65-69, 70-74, and 75+ years), sex, diagnosis (osteoarthritis, other), and hospital yearly operation count (< 100 operations yearly, ≥ 100 operations yearly); 5166 matched pairs were identified. Revision for any reason was considered as the failure endpoint of followup. Implant survival (the proportion not revised) was calculated from corresponding cumulative incidence function adjusted for patient death as a competing event for revision. Large-diameter head MoM implant group revision hazard ratios with 95% confidence intervals were estimated with age group, sex, diagnosis, and hospital yearly operation count as confounding factors in a Cox regression model. RESULTS: Ten-year survivorship free from all-cause revision was lower for THAs that used a large-diameter femoral head than it was for the control group of conventional THA (83% [95% confidence interval {CI}, 82%-84%] versus 92% [95% CI, 91%-93%]). At the implant level, every large-diameter head MoM THA had a higher risk for revision compared with the conventional THA control group from the fourth postoperative year onward. The highest survival of MoM THA was 88% (95% CI, 86%-90%) for the ReCap/Bimetric and the lowest survival was 46% (95% CI, 41%-51%) for the recalled ASR with either the Summit® or Corail® stem. The most common revision reason in the MoM THA group was adverse reaction to metal debris, whereas dislocation was predominant in the conventional THA control group. CONCLUSIONS: The revision rate for all large-diameter head MoM THAs in this timeframe in the Finnish Arthroplasty Register is unacceptably high and in our view supports the decision to abandon their use. In agreement with the directives of other national organizations, we recommend regular followup of all patients with large-diameter head MoM THA. Based on our results, strict guidelines for followup should be maintained over the lifetime of the implant to assess patient symptoms and recommend revision when indicated. LEVEL OF EVIDENCE: Level III, therapeutic study.

What Is the Long-term Survivorship of Cruciate-retaining TKA in the Finnish Registry?

BACKGROUND: Survival of cruciate-retaining (CR) TKA is generally good, but there may be important differences in survivorship among devices, and different designs may not all be equally patellar-friendly. Large registry databases are needed to identify small but important differences between devices. QUESTIONS/PURPOSES: The purposes of this study were (1) to assess the long-term survivorship of the most common CR TKA devices with revision for any reason as the endpoint and compare the revision risk of these devices after controlling for the potentially confounding variables of age, sex, hospital volume, and primary diagnosis; and (2) to analyze these same devices with revision for secondary resurfacing of the patella as a separate endpoint. METHODS: Data were collected from the Finnish Arthroplasty Register. Over 95% of all primary TKAs are captured in the Finnish Register. We assessed Kaplan-Meier (KM) survivorship for each of the four most frequently used CR TKA designs used between years 2005 and 2015: Triathlon CR (n = 34,337), Nexgen CR Flex (n = 15,723), PFC Sigma CR (n = 15,541), and Vanguard CR (n = 9461), with revision for any reason as the endpoint. Revision was defined as a reoperation in which at least one of the components was exchanged (including insert exchange). Revisions in which the patella was not resurfaced at the primary operation and was resurfaced in the revision were studied as a separate endpoint. The mean followup times were 4.0 (range, 0-11.0) years for Triathlon CR, 3.8 (range, 0-11.0) years for Nexgen CR Flex, 5.1 (range, 0-11.0 ) years for PFC Sigma CR, and 4.9 (range, 0-10.9) years for Vanguard CR (p < 0.001). The group demographics were clinically comparable. We compared the risk of revision of these devices in the Cox multiple regression model with adjustment for hospital volume, age, sex, and primary diagnosis. There were some differences in the incidence of patellar resurfacing at the time of index arthroplasty (Nexgen CR flex 18.7%, PFC Sigma CR 18.4%, Triathlon CR 11.3%, Vanguard CR 14.4%), which was controlled by the Cox model. Implant survival analyses for Triathlon CR, Nexgen CR Flex, and PFC Sigma CR were also performed at the hospital level for the 25 largest TKA providers in Finland. RESULTS: The overall 10-year KM survivorships were 96% (95% confidence interval [CI], 95-96) for Nexgen CR Flex, 96% (95% CI, 96-97) for PFC Sigma CR, 94% (95% CI, 93-95) for Triathlon CR, and 94% (95% CI, 93-95) for Vanguard CR. After controlling for potential confounding variables like age, sex, hospital volume, and primary diagnosis, both Triathlon CR (hazard ratio [HR], 1.4; 95% CI, 1.2-1.6; p < 0.01) and Vanguard CR (HR, 1.4; 95% CI, 1.2-1.6; p < 0.01) had an increased risk for revision compared with the Nexgen CR Flex (the reference device). When revision with patellar resurfacing served as the endpoint, after controlling for those same confounding variables, Triathlon CR had a higher risk for revision than Nexgen CR Flex (HR, 1.8; 95% CI, 1.4-2.2; p < 0.01). CONCLUSIONS: Despite slight differences among the studied devices, the overall 10-year survivorship of the current devices studied was good. However, there were differences in implant survival between the study devices, especially when revision for late patellar resurfacing was analyzed. Further studies adjusted for additional hospital and surgeon variables will be needed to examine and confirm our results. LEVEL OF EVIDENCE: Level III, therapeutic study.

Predictors of treatment outcome in prosthetic joint infections treated with prosthesis retention.

PURPOSE: The reported success rates of debridement, antibiotics, and implant retention (DAIR) for prosthetic joint infections (PJIs) vary widely. Several risk factors have been described for treatment failure, but they vary between studies. The purpose of this study was to evaluate the predictors of DAIR failure in PJI treatment and to assess the efficacy of rifampin combined with ciprofloxacin versus rifampin combined with other antibiotics in staphylococcal PJIs. METHODS: Patients with PJI that underwent DAIR for the first time between February 2001 and August 2009 were identified retrospectively in the hospital's patient databases. A total of 113 PJI cases with early postoperative or acute haematogenous PJI were followed for up to two years from the start of treatment. RESULTS: In univariate analysis, variables significantly associated with treatment failure were acute haematogenous infections (p = 0.022), leucocyte count at admission > 10 × 10(9)/l (p < 0.01), pain in the joint (p < 0.01), and ineffective empirical antibiotics (p < 0.01). In a multivariate Cox model, leucocyte count > 10 × 10(9)/l and ineffective empirical antibiotics were significant risk factors for failure. Compared to rifampin-ciprofloxacin, the hazard ratio (HR) for treatment failure was significantly increased in the rifampin-other antibiotics group (HR 6.0, 95% CI 1.5-28.8, p = 0.014) and the group treated without rifampin (HR 14.4, 95% CI 3.1-66.9, p < 0.01). CONCLUSIONS: Rifampin-ciprofloxacin combination therapy was significantly more effective than rifampin combined with other antibiotics. Effective empirical antibiotics are essential for successful PJI treatment.

Two-stage revision for prosthetic joint infection: outcome and role of reimplantation microbiology in 107 cases.

Two-stage revision is widely used for the treatment of prosthetic joint infections. However, the duration of antibiotic treatment between stages and role of reimplantation microbiology are controversial. The purpose of this study was to evaluate the outcome and influence of the reimplantation microbiology of two-staged revisions with 6 weeks of antibiotic treatment. We retrospectively reviewed 107 patients treated with two-stage revision between 2001 and 2009. The overall treatment success rate was 94.4%. The reimplantation cultures were positive in 5/97 (5.2%) cases, and only one of them failed. Therefore, we achieved excellent results with a 6-week course of antibiotics between stages in two-stage revision. Positive reimplantation cultures do not seem to be associated with worse outcomes.