Revision Total Knee Arthroplasty Procedures Research Articles

The Microbiology of Knee Prosthetic Joint Infection and its Influence on Persistent Infection.

Periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) is a severe complication causing a significant burden. The study aims were to establish the epidemiology of microorganisms in TKA PJI, the rate of persistent infection requiring further surgery, and the risk factors for this. Microbiological specimens between June 2002 and March 2017 at five regional hospital sites were identified with revision TKA procedures in the National Joint Replacement Registry. The time between procedures, type of revision strategy, and any subsequent further revision operations were collected. At minimum 2-year follow-up, 174 revision TKA were identified, with a mean patient age of 69 ± 11 years. A broad range of pathogens were identified. Fifty cases (29%) had persistent infection requiring at least one further operative procedure, 13 cases required 3 or more. Coagulase-negative Staphylococcus species (CNS) was seen most with failed surgery, polymicrobial infections also posing a significant risk factor. The best chance of a successful PJI surgical strategy was < 12 months from primary TKA, with the greatest risk between 3 and 5 years (p < 0.05). Younger age significantly increased the risk of further surgery (p < 0.05). Management varied; 103 (59%) debridement, antibiotic therapy and implant retention, with further surgery in 29%; 45 (17%) single-stage revision, with further surgery in 13%; and 26 (15%) two-stage revision, with further surgery in 12%. This study presents the most common causative pathogens for PJI in TKA, and the high rate of persistent infection after initial revision surgery. Risk factors for persistent infection and further revision surgery were polymicrobial and CNS infections, patients who presented between 3 and 5 years following primary TKA, and younger age. This study therefore raises important risk factors and areas for future research to reduce the burden of multiple operations after PJI.

3D-Printed Metaphyseal Cones in Revision Total Knee Arthroplasties: Excellent Survivorship of 740 Cones at 5 Years.

Porous metaphyseal cones are frequently utilized during revision total knee arthroplasty (TKA) procedures. The purpose of the present study was to evaluate 3D-printed metaphyseal cones used for revision TKA, with specific emphasis on implant survivorship, radiographic appearance, and clinical outcomes after short-term follow-up. We identified 740 cones (498 tibial, 242 femoral) that had been inserted during 533 revision TKA procedures that had been performed at a single tertiary care academic institution. Aseptic loosening (n = 199), periprosthetic joint infection (PJI) (n = 183), and instability (n = 84) were the most common reasons for the index revision. Type-2B or 3 bone loss was present in 67% of the knees. The mean age was 66 years, the mean body mass index was 34 kg/m2, and 55% of the patients were female. Serial radiographs were reviewed. The mean duration of follow-up was 4 years. The 5-year cumulative incidence of cone revision for aseptic loosening was 1% (95% confidence interval [CI], 0% to 3%). The 5-year cumulative incidence of any cone revision or removal was 6% (95% CI, 4% to 9%). In total, 37 cones (19 femoral, 18 tibial) were revised, with PJI (n = 23; 14 recurrent), periprosthetic femoral fracture (n = 3), arthrofibrosis (n = 3), and aseptic loosening of the femoral component and femoral cone (n = 3) as the most common reasons for cone revision. The 5-year cumulative incidence of any TKA re-revision was 14% (95% CI, 11% to 18%). There were a total of 67 re-revisions, with PJI (n = 38), persistent drainage (n = 6), and extensor mechanism disruption (n = 3) being the most common reasons. Radiographically, 2 unrevised femoral cones and 1 unrevised tibial cone appeared to be possibly loose; all 3 cones were in knees with distal femoral replacements or hinged constructs. This large series showed that 3D-printed titanium metaphyseal cones were very durable at short-term follow-up, with a 5-year cumulative incidence of cone revision for aseptic loosening of 1%. PJI was the most common reason for cone revision and any revision. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

A case of primary total knee arthroplasty revision using CORI system

Total Knee Arthroplasty (TKA) is a common surgical procedure used to treat end-stage osteoarthritis of the knee. The increasing adoption of computer-assisted and robotic assisted techniques in total joint arthroplasty has been found to enhance the accuracy of component placement. Short-term studies have indicated improved survival rates in unicompartmental knee arthroplasty with the use of robotic assistance. While robotic technology has proven beneficial in revising procedures like converting unicompartmental knee arthroplasty to TKA, there is limited information on its application in revising primary TKA. This case report details the use of robotic-assisted technology with CORI system in the revision of TKA. The incorporation of robotic assistance during TKA revision surgeries may contribute to better alignment of components and potentially increase the longevity of the prosthetic implant. However, further research is essential to explore the impact of robotic assistance on the overall survival rates and cost-effectiveness of revision TKA procedures.

Does medullary diameter to stem width ratio and stem length affect outcomes of revision total knee arthroplasties? A case series.

This study aimed to investigate the relationship between the ratio of stem size to intramedullary canal diameter, stem length, and functional outcome in revision total knee arthroplasty (RTKA) procedures, which remains largely unexplored in the current literature. A single surgeon series of RTKA procedures performed between October 2014 and November 2022 were included in this case series, and data were analyzed retrospectively. A total of 32 patients (27 females, 5 males; mean age: 73.2±8.1 years; range, 52 to 88 years) were identified, with a minimum follow-up period of five months and a maximum of eight years. Filtering the patients based on >24 month follow-up, we were left with 13 patients aged between 65 and 88 (mean 74.9±6.9) years. The latest X-rays of patients were analyzed, and the ratio of intramedullary canal diameter to stem width was calculated for both femur and tibia in both anteroposterior and lateral planes. Household income, preoperative C-reactive protein, erythrocyte sedimentation rate, comorbidities, body mass index, and implant dimensions were also recorded. Postoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form-12 (SF-12) scores, and range of motion (ROM) measurements were used to evaluate functional outcome. A moderate negative relationship between the tibial canal fill ratio (CFR) in anteroposterior views and ROM of the patients was noted. Additionally, a significant positive correlation was found between SF-12 physical score and CFR in lateral view. A moderate level of correlation between femoral CFR in anteroposterior views was also established. Due to insufficient data, joint ROM data did not show normal distribution. Therefore, a cutoff value indicating the relationship between the stem size and knee ROM could not be calculated using receiver operating characteristic analysis. Multiple regression analysis did not yield significant results, suggesting that hypothesized predictor variables were not sufficient to predict the variation in functional scores. Otherwise, no clear statistical importance or correlation between functional scores, such as WOMAC or SF-12, and CFR was found. In conclusion, the findings suggest that other factors, such as other patient characteristics, surgical techniques, or implant designs, may have a more substantial impact on the functional outcomes in RTKA patients.

Revision total knee arthroplasty results in financial deficits within the Swiss healthcare system.

Revision total knee arthroplasty (RTKA) results in high costs with inadequately low reimbursement in different healthcare systems. Therefore, a financial analysis was performed comparing costs and reimbursements of primary total knee arthroplasty (PTKA) versus RTKA using financial and total knee arthroplasty-register data from a large tertiary hospital, the Cantonal Hospital of St. Gallen (KSSG), Switzerland. All PTKA and RTKA performed between January 2012 and September 2019 at the KSSG were included. Financial and TKA-register data for each case were collected, including detailed cost allocation, reimbursement, patients' insurance status, type and indication for surgery and length of hospital stay. RTKA was further subdivided in one-stage and two-stage RTKA. Direct hospital costs were analyzed and compared to reimbursement in both groups. Cost-coverage ratios were calculated. 730 PTKA and 106 RTKA were included. The RTKA group contained 66 one-stage and 40 two-stage RTKA. Cost-coverage ratio for PTKA and RTKA showed to be 110.9% and 81.3%, respectively. Cost-coverage ratio was lower for two-stage RTKA than for one-stage RTKA with 74.1% and 92.3%, respectively. RTKA leads to financial deficits especially for tertiary hospitals within the Swiss healthcare system. Restructuring of the reimbursements for PTKA and RTKA should be considered in favor of RTKA. Otherwise, tertiary hospitals will face a growing financial burden with the constantly increasing annual number of RTKA procedures, predominantly performed in this type of hospitals. III.

Survivorship and Etiologies of Failure in Single-stage Revision Arthroplasty for Periprosthetic Joint Infection: A Meta-analysis

Single-stage revision arthroplasty for periprosthetic joint infection (PJI) may yield comparable infection-free survivorship with two-stage revision arthroplasty. It is unclear if the most common mode of failure of single-stage revision arthroplasty is infection or aseptic loosening. In this meta-analysis, we sought to (1) determine survivorship and (2) compare rates of different etiologies of failure of single-stage revision total hip arthroplasty (THA) and total knee arthroplasty (TKA). Preferred Reporting Items for Systematic Review and Meta-analyses guidelines search was done using search terms for "single stage revision," "exchange arthroplasty," "periprosthetic infection," "PJI," and "single stage." Patient demographics such as age, body mass index, and mean follow-up time were recorded. Overall survivorship and rates of revision surgery were aggregated using a random-effects model. Comparison of septic and aseptic loosening rates was done by risk difference and associated 95% confidence interval (CI) calculation. Twenty-four studies were identified with 2,062 and 147 single-stage revision THA and TKA procedures performed between 1984 and 2019, respectively. The weighted mean follow-up and age were 69.8 months and 66.3 years, respectively, with 55% men overall. The all-cause revision surgery rate was 11.1% and 11.8% for THA and TKA, respectively. The revision surgery rate secondary to infection and aseptic loosening and associated 95% CI for the risk difference for THA and TKA was 5.5% and 3.3% (-1.7% to 5.0%), and 3% and 8.8% (-11.4% to 2.3%), respectively. Revision surgeries due to instability and fracture combined and mortality rate were both less than 3%. Single-stage revision THA and TKA for PJI demonstrated overall high rates of survivorship, low mortality, and revision surgeries secondary to infection and aseptic loosening to be equivalent. Aseptic loosening after single-stage revision TKA might be higher than in primary TKA. As implant survivorship from infection improves in PJI, surgeons should be aware of aseptic loosening as an equally common mode of failure.

Surgical and patient-reported outcomes after total knee arthroplasty requiring soft tissue flap reconstruction – A 12-year experience from high-volume arthroplasty hospital

This study investigates the outcomes of complex knee joint reconstructions performed by an orthoplastic surgery team at a tertiary referral hospital. Retrospective review of all the total knee arthroplasty (TKA)/revision TKA (rTKA) procedures with soft tissue flap reconstruction performed between 2008 and 2019 was conducted. Patients were stratified into two groups according to the urgency of surgery: scheduled non-complicated (SNC) and emergent complicated (EC). The whole study cohort was also categorized into non-infected and infected groups. Of 20,184 TKAs operated, 58 patients required flap reconstruction (SNC group n=27; EC group n=31). The most common reconstruction was medial gastrocnemius flap (74%). Mean follow-up time was 31.9 months. Functional knee joint salvage was achieved in 96.3% the SNC group and in 80.6% the EC group patients (p=0.07). Transfemoral amputation rates were 3.7% in the SNC group vs. 6.5% in the EC group (p=0.36). Oxford Knee Score was 34.5vs. 25.5 (p=0.21), and range of motion was 100⁰ vs. 93⁰ (p=0.37) in the SNC and EC groups, respectively. Superior functional knee joint salvage rates were achieved in the non-infected group compared to the infected group (97.1% vs. 75.0%, p=0.004). However, the transfemoral amputation rate was nearly three-fold in the infected group (8.3% vs. 2.9%, p=0.36). Estimated five-year survival with functional knee joint was higher in the non-infected group (p=0.03). Both the SNC and EC groups had similar acceptable limb salvage rates, and functional and PROM outcomes. Infection reduces the probability of a functional knee joint after TKA and flap reconstruction.

Manipulation Under Anesthesia Is Associated With an Increased Rate of Early Total Knee Arthroplasty Revision.

Manipulation under anesthesia (MUA) after total knee arthroplasty (TKA) frequently has been used as a first-line treatment to restore functional range of motion after unsuccessful physical therapy. Although there are studies reporting that MUA assisted in restoring range of motion, there is a paucity of literature on the influence of MUA on the risk of revision TKA. The goal of our study was to determine whether MUA was associated with an increase in the rate of revision TKA within 2 years of MUA. A total of 49,310 patients within a single institution who underwent primary TKA were identified from 1999 to 2019. Data were matched at a 1:3 ratio (TKA with and without MUA, respectively) based on age, sex, and body mass index. A matched comparison cohort was conducted, with the MUA cohort having 575 patients and the no MUA cohort having 1725 patients. A statistically significant increase in the rate of noninfectious etiology revision TKA was found in the MUA cohort (7.3%) compared with the no MUA cohort (4.9%; P=.034). The most common reason for revision TKA after MUA was persistent stiffness, including arthrofibrosis and ankylosis; however, aseptic loosening, ligamentous instability, and periprosthetic fracture were found to be responsible for 21.4% of revision TKA procedures. Although MUA is a commonly performed procedure for treating stiffness after primary TKA, the orthopedic surgeon should counsel patients on the association of increased rate of revision TKA after MUA, most commonly, persistent stiffness. [Orthopedics. 2022;45(5):270-275.].

Impact of resident involvement on complication rates in revision total knee arthroplasty

ObjectivesThe number of revision total knee arthroplasty (TKA) procedures continues to rise, a direct consequence of the increase in primary TKA. The number of arthroplasty-trained orthopaedic surgeons has failed to increase at a corresponding rate, and the increased burden will ultimately fall on non-specialized orthopaedists. Resident involvement in primary TKA has not been found to increase postoperative complications, but revision TKA is more complex and the impact of resident involvement has not been well studied. MethodsUsing the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, this study identified 1834 revision TKA procedures between the years 2008 and 2012. Of these procedures, 863 included resident involvement. Demographic information, comorbidities, operative times, length of stay (LOS), and 30-day postoperative complications were stratified by resident and non-resident involvement and analyzed. ResultsResident involvement was not associated with a significant increase in short-term complications. Operative times were significantly longer with resident involvement (147.50 min with resident involvement vs. 124.55 min without a resident, p < 0.001). Length of stay after procedures with resident involvement was higher by 0.34 days, but this did not reach significance (p = 0.061). ConclusionResident involvement in revision total knee arthroplasty was associated with a significant increase in operative time; however, there were no significant increases in postoperative complication rates within 30 days. These findings support continued resident involvement in revision total knee arthroplasty cases and postoperative management.

Implant survivorship, functional outcomes and complications with the use of rotating hinge knee implants: a systematic review

BackgroundWith more complex primary and revision total knee arthroplasty procedures there is often the need to use more constrained prostheses. This study aims to investigate patient-relevant outcomes following primary and revision rotating-hinged total knee arthroplasty.MethodsElectronic searches were performed using four databases from their date of inception to January 2021. Relevant studies were identified, with data extracted and analysed using PRIMSA guidelines.ResultsNineteen studies were included, producing a cohort of 568 primary and 413 revision rotating hinge total knee arthroplasties (TKAs). Survival was assessed at 1-, 5-, and 10-year post-implantation. Sensitivity analyses based on person-time incidence ratios (PTIRs) were prespecified for studies not reporting survival at these timepoints. From the primary hinge TKA cohort, the median survival at 1 year was 93.4% and at 10 years it was 87%. The PTIR at long-term follow-up of this primary cohort was 1.07 (95% CI 0.4–1.7) per 100 person-years. From the revision hinge TKA cohort, the median survival at 1 year was 79.6%, and at 10 years it was 65.1%. The PTIR at long term-follow-up of this revision cohort was 1.55 (95% CI 0.9–2.3) per 100 person-years. Post-operative flexion range of motion (ROM) was 110° for primary hinge TKA and 103° for revision hinge TKA. Compared with baseline, the Knee Society Score (KSS) and Knee Society Function Score (KSFS) improved for both groups post-operatively (primary: KSS 17 to 86, KSFS 28 to 58; revision: KSS 37 to 82, KSFS 34 to 61).ConclusionThe quality of the evidence for patient-relevant outcomes following hinged knee arthroplasty was limited. While there is the potential for high early revision rates, where successful, large functional benefits may be achieved.

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

Prosthetic joint infection (PJI) of the knee carries significant morbidity, mortality, and economic cost. We hypothesize that obese and poor medical hosts will have a significant and additive increase in failure rate undergoing 2-stage revision total knee arthroplasty for PJI. All 2-stage revision total knee arthroplasty procedures for PJI performed at one institution were identified between 2005 and 2020. In total, 144 patients were included and defined as success or failure based on published criteria regarding infection eradication, further intervention, or mortality. The American Society of Anesthesiologists score and the Charlson Comorbidity Index were utilized to assess host grade. Patient, surgical, and microbiologic variables were investigated with univariable and multivariable analysis to explore association with risk of failure. In the cohort, 32.4% of patients failed with mean follow-up of 5.1 years. In multivariable analysis, the number of major operations requiring arthrotomy and implantation of new material between the primary and first stage, host grade, and elevated body mass index were the major contributors to failure. Combining these factors, with body mass index >30 and 2 or more major operations, the failure rate increased to 76.5% and 71.4% respectively for American Society of Anesthesiologists score 3 (P ≤ .001) and Charlson Comorbidity Index ≥2 (P ≤ .001). In this cohort, multiple major operations between the primary and first stage, host grade, and obesity were the major contributors to failure. When combining these factors, patients had an additive increase in failure rate. Treatments such as amputation or less invasive options and suppression should be discussed and considered in these patients.

Rotating Hinge Revision Total Knee Arthroplasty for Severe Arthrofibrosis.

First, remove all soft-tissue and osseous sources of stiffness and adequately expose the knee, then remove all previous components. Create a stable and balanced extension gap, and, conversely, a relatively loose flexion gap, which allows for a substantial increase in range of motion. Then, in order to prevent instability in flexion, a rotating hinge prosthesis is utilized, which allows for appropriate kinematic motion despite gap imbalance. Additional steps to regain flexion include medial and lateral distal femoral partial condylectomies, as well as patellar component revision. The first line of treatment for stiffness following total knee arthroplasty is nonoperative and is mainly focused on physical therapy3. Manipulation under anesthesia can also be performed within the first 12 weeks postoperatively3. Surgical treatments can include arthroscopic debridement as well as open debridement with possible polyethylene liner exchange. If there is a mechanical cause for stiffness, then this should also be addressed surgically. For cases of arthrofibrosis without a clear mechanical etiology or for cases in which the above treatment has failed, complete revision of the femoral and tibial components should be considered3. An alternative option to the technique proposed here is to utilize a varus-valgus constrained implant. Revision with a hinged implant allows for a more aggressive approach to regaining motion, as compared with all other surgical alternatives. By revising all components, the surgeon is able to remove all sources of stiffness and reconstruct the knee until as much range of motion as possible is achieved. Unfortunately, even with balanced extension and flexion gaps, refractory stiffness is common. A solution for this residual stiffness is to unbalance the gaps and create a loose flexion gap. By doing so, the surgeon is advised to switch to a hinged implant to create a kinematically balanced knee. Any other revision implant, such as a varus-valgus constrained implant, would risk flexion instability. Several studies have examined the use of revision total knee arthroplasty with a hinged implant for arthrofibrosis and have showed substantial improvements in knee range of motion. Bingham et al. showed that the rotating hinge group had a 20° improvement in range of motion (p = 0.048)1. Hermans et al. found a 35.8° flexion gain in the hinge group compared with a 14.2° flexion gain in the varus-valgus constrained group (p = 0.0002)4. van Rensch et al. found a median gain of 45° of range of motion5. Patients should be aware that this procedure involving the use of a hinged implant has similar risks to other revision total knee arthroplasty procedures; specifically, there is a risk of recurrent arthrofibrosis as well as mechanical complications1,5. Achieve adequate exposure with a quadriceps snip.Perform a thorough synovectomy and debridement.Create a balanced extension gap with a relatively loose flexion gap.Distalize the joint line by resecting additional proximal tibia in cases of patella baja.Beware of refractory stiffness as a result of a scarred extensor mechanism.Consider revising the patellar component.Consider performing a partial condylectomy at the medial and lateral distal aspects of the femur. TKA = total knee arthroplastyAP = anteroposteriorCT = computed tomographyMRI = magnetic resonance imagingRHK = rotating hinge kneeNSAIDs = nonsteroidal anti-inflammatory drugs.

The Epidemiology of Revision Total Knee Arthroplasty.

With an expected increase in total knee arthroplasty (TKA) procedures, revision TKA (rTKA) procedures continue to be a burden on the United States health care system. The evolution of surgical techniques and prosthetic designs has, however, provided a paradigm shift in the etiology of failure mechanisms of TKA. This review can shed light on the current reasons for revision, which may lead to insights on how to improve outcomes and lower future revision risks. We will primarily focus on the epidemiology of rTKA in the present time, but we will also review this in the context of various time periods to see how the field has evolved. We will review rTKAs: 1) prior to 1997; 2) between 1997 and 2000; 3) between 2000 and 2012; and 3) in the modern era since 2012. We will further subdivide each of the sections into reasons for early (first 2 years after index procedure) versus late revisions (greater than 2 years after index procedure). In doing so, it was determined that prior to 1997, the most prevalent causes of failure were infection, patella failure, polyethylene wear, and aseptic loosening. After a major shift of failure mechanisms was described by Sharkey et al, polyethylene wear and aseptic loosening became the leading causes for revision. However, with the improved manufacturing technology and implant design, polyethylene wear was replaced with aseptic loosening and infection as the leading causes of failure between 2000 and 2012. Since that time, in the modern era of TKA, mechanical loosening and infection have taken over the most prevalent causes for failure. Hopefully, with continued developments in component design and surgical techniques, as well as increased focus on infection reduction methods, the amount of rTKA procedures will decline.

Cost of septic and aseptic revision total knee arthroplasty: a systematic review

BackgroundThe increasing incidence of primary total knee arthroplasty (TKA) has led to an increase in both the incidence and the cost burden of revision TKA procedures. This study aimed to review the literature on the cost of revision TKA for septic and aseptic causes and to identify the major cost components contributing to the cost burden.MethodsWe searched MEDLINE (OvidSp), Embase, Web of Science, Cochrane Library, EconLit, and Google Scholar to identify relevant studies. Selection, data extraction and assessment of the risk of bias and cost transparency within the studies were conducted by two independent reviewers, after which the cost data were analysed narratively for 1- or 2-stage septic revision without re-revision; 2-stage septic revision with re-revision; and aseptic revision with and without re-revision, respectively. The major cost components identified in the respective studies were also reported.ResultsThe direct medical cost from the healthcare provider perspective for high-income countries for 2-stage septic revision with re-revision ranged from US$66,629 to US$81,938, which can be about 2.5 times the cost of 1- or 2-stage septic revision without re-revision, (range: US$24,027 – US$38,109), which can be about double the cost of aseptic revision without re-revision (range: US$13,910 – US$29,213). The major cost components were the perioperative cost (33%), prosthesis cost (28%), and hospital ward stay cost (22%).ConclusionsSeptic TKA revision with re-revision for periprosthetic joint infection (PJI) increases the cost burden of revision TKA by 4 times when compared to aseptic single-stage revision and by 2.5 times when compared to septic TKA revision that does not undergo re-revision. Cost reductions can be achieved by reducing the number of primary TKA that develop PJI, avoidance of re-revisions for PJI, and reduction in the length of stay after revision.Trial registrationPROSPERO; CRD42020171988.

Clinical Outcomes Following Revision Total Knee Arthroplasty: Minimum 2-Year Follow-up

BackgroudThe longer-term outcomes of revision total knee arthroplasty are not well described in the current literature. Managing patient expectations of revision total knee arthroplasty can be challenging for orthopedic surgeons due to a paucity of data to guide decision-making. We present outcomes of revision total knee arthroplasty performed by a single surgeon over a 12-year period from 2004 through 2015.MethodsA retrospective review of hospital and private medical records demonstrated 202 revision total knee arthroplasties performed by the senior author in 178 patients from 2004 through 2015. Of these, 153 patients were available for assessment. Patients were contacted and invited to participate in a structured telephone interview to assess Oxford Knee Score (OKS) and patient satisfaction. All patients received the PFC (Depuy) prosthesis at a single institution and were followed up for minimum 2 years postoperatively at the time of review. Retrospective chart review was used to obtain other data for analysis including patient demographics, preoperative and postoperative range of motion (ROM), and intraoperative details.ResultsThis cohort demonstrated a 93.5% survival rate and an 85% satisfaction rate at a mean of 6.5 years postoperatively. Mean ROM improved from 100° (range, 5°–145°) to 112° (range, 35°–135°) (p < 0.001). The mean OKS was 39.25 (range, 14–48). The factors associated with improved postoperative outcomes included male gender, fewer previous revision total knee arthroplasty procedures, increased preoperative ROM, and receiving a less constrained implant.ConclusionsThis study provides a comprehensive description of outcomes following revision total knee arthroplasty in a large patient cohort with a long follow-up. Although revision total knee arthroplasty is a challenging and complex aspect of arthroplasty surgery, high patient satisfaction and good functional outcomes can be achieved for the majority of patients.

A Reliable Surgical Approach to Revision Total Knee Arthroplasty.

BackgroudThe surgical exposure obtained in revision total knee arthroplasty should facilitate the utilisation of instrumentation and implants, including adjuncts such as stemmed prostheses, bone allograft, and artificial augments. We have previously identified within this cohort of revision total knee arthroplasty patients a high satisfaction rate of 93.5% at a mean 6.5 years of follow-up and a high level of postoperative function. We, therefore, seek to describe in detail the operative technique and perioperative care and report the early postoperative complications.MethodsWe report on the surgical approach, closure technique, and postoperative care used by the senior author for revision total knee arthroplasty procedures. The patient demographics, intraoperative details, and postoperative outcomes are also reported. We aim to provide a clear description of the intraoperative technique and postoperative outcome, facilitating adoption or comparison with other surgeons or techniques. Patient inclusion criteria were revision total knee arthroplasty performed by the senior author using the PFC (Depuy) prosthesis at John Flynn Private Hospital with a minimum of 2-year postoperative follow-up. A retrospective chart review was combined with a structured telephone assessment questionnaire to assess outcomes.ResultsA total of 202 revision total knee arthroplasties were available for follow-up in 185 patients. The mean 1-year postoperative range of motion was 110°. Key features of surgical approach include incision planning, soft-tissue plane development, parapatellar scar debridement, safe removal of implants, management of bone defects, and closure technique. The overall 90-day complication rate was 9%, including 4.4% requiring manipulation under anaesthesia and 3% superficial surgical site infections (1 patient requiring intravenous antibiotics).ConclusionsWe suggest that the described technique is reproducible and reliable. It rarely requires modification and facilitates successful postoperative outcomes with a low complication rate. The adoption of this surgical technique allows surgeons to approach complex knee arthroplasty with confidence in the appropriate exposure of anatomy, facilitating subsequent steps in their arthroplasty procedures.

Completeness and capture rate of publicly funded arthroplasty procedures in the New Zealand Joint Registry.

Registry-based studies have become more common due to the availability of a large study cohort. However, the validity of findings is dependent on the completeness of the registry. This study aimed to validate the capture rate of the New Zealand Joint Registry (NZJR) by matching procedures that have been recorded separately via clinical coding by the New Zealand Government's National Surgical Site Infection Improvement Programme (SSIIP). The National Health Index, a unique identification code for all patients, was combined with the arthroplasty procedure performed (primary total knee arthroplasty (TKA), primary total hip arthroplasty (THA), revision TKA or revision THA) and operation side. Publicly funded procedures recorded in the NZJR were matched with procedures recorded by the SSIIP on a record-by-record basis. This identified the total number of arthroplasty procedures performed in New Zealand, which was used as the denominator value to calculate the procedure capture rate of the NZJR. Between 2013 and 2018, 24 556 primary TKA, 28 970 primary THA, 2107 revision TKA and 4263 revision THA procedures were recorded by both datasets. The NZJR recorded 95.5% of primary TKA procedures, 96.3% of primary THA procedures, 97.1% of revision TKA procedures and 95.2% of revision THA procedures. The NZJR recorded >95% of publicly funded arthroplasty procedures. In contrast, there were inaccuracies in clinical coding by hospitals, particularly with revision procedures, demonstrating the benefits of an arthroplasty registry. However, data recorded by an infection surveillance programme may supplement arthroplasty registry data to strengthen the quality of research.

Trabecular Metal Cones Combined With Short Cemented Stem Allow Favorable Outcomes in Aseptic Revision Total Knee Arthroplasty

BackgroundThe purpose of this study was to compare the functional outcomes and implant survivorship at a minimum of 5 years of follow-up of several reconstruction techniques with or without metaphyseal cone and stems of variable length. MethodsA retrospective comparative matched analysis was performed from 2 prospectively collected databases. Only patients who underwent revision total knee arthroplasty procedures for aseptic causes using a single design of rotating hinge knee with a minimum of 5 years of follow-up were analyzed. Patients were separated into 3 groups: trabecular metal (TM) cones + short cemented stems (TM + short stem [SS]), TM cones + long uncemented stems (TM + long stem [LS]), and no cone (NC) + long uncemented stems (NC + LS). A matching process based on age (±5 years) was realized. ResultsAbout 99 patients were included; 33 in the TM + SS group, 33 in the TM + LS group, and 33 in the NC + LS group. The mean time of follow-up was 9.3 years. A significant difference of the improvement of subscale pain, symptom, activities of daily living, quality of life of the Knee Injury and Osteoarthritis Outcome score and knee, function of the Knee Society Score was observed in favor of TM + SS group compared with the 2 other groups. At 8 years of survivorship, the components free of revision for any cause were 90.9% for the TM + SS group, 84.9% for the TM + LS group, and 90.6% for the NC + LS group. ConclusionThe use of a short cemented tibial stem combined with a TM cone in revision total knee arthroplasty offers identical survival rate with better functional outcome compared with the use of a long uncemented stem associated with TM cones or metallic augments at a minimum of 5 years of follow-up.

The stiff total knee arthroplasty: causes, treatment modalities and results.

It is clear that the stiff total knee arthroplasty (TKA) is a multifactorial entity associated with preoperative, intraoperative and postoperative factors.Management of the stiff TKA is best achieved by preventing its occurrence using strategies to control preoperative factors, avoid intraoperative technical errors and perform aggressive, painless postoperative physical medicine and rehabilitation; adequate pain control is paramount in non-invasive management.Careful attention to surgical exposure, restoring gap balance, minimizing surgical trauma to the patellar ligament/extensor mechanism, appropriate implant selection, pain control and adequate physical medicine and rehabilitation (physiotherapy, Astym therapy) all serve to reduce its incidence.For established stiff TKA, there are multiple treatment options available including mobilization under anaesthesia (MUA), arthroscopic arthrolysis, revision TKA, and combined procedures.Cite this article: EFORT Open Rev 2019;4:602-610. DOI: 10.1302/2058-5241.4.180105

Epidemiology of Revision Total Knee Arthroplasty: A Single Center's Experience.

Background:There has been a gradual increase in the revision TKA (RTKA) workload due to expanding indications of total knee arthroplasty (TKA), coupled with improving patient longevity. Western countries are already looking at their data on RTKA to plan for the future heath care needs of these patients. Limited data is available on RTKA from developing countries. Our study attempts to fill this gap in knowledge.Materials and Methods:We prospectively documented details of all RTKA performed at our centre for a period of six years (2011-16). We recorded the volume, causes and time to failure from index surgery of all RTKA and further recorded microbiological pattern in septic failures. We looked at the proportion of each cause of failure and time from index surgery.Results:Of the 5068 TKA procedures performed from January 2011 to December 2016, 201 (4%) were first-time revisions. The predominant cause of revisions was prosthetic infection (61%) followed by aseptic loosening (18%) and instability (7%). In the early, mid term, and late-failure groups, prosthetic infection remained the main cause of failure. In 47% of the septic revisions, the offending organisms could be identified and of those identified most (67%) were Gram-negative.Conclusion:The volume of first-time RTKA procedures (4%) at our center remained low compared with that of the Western countries. In Western countries, the incidence of late aseptic failures was higher than that of early-septic failures, whereas in our study, revisions were more commonly performed in the early-failure group (48%) and most failures were due to prosthetic infection (61%).