What Are the Causes of Revision Total Knee Arthroplasty in Japan?

Background

There is limited information regarding the cause of revision TKA in Asia, especially Japan. Owing to differences in patient backgrounds and lifestyles, the modes of TKA failures in Asia may differ from those in Western countries.

Questions/purposes

We therefore determined (1) causes of revision TKA in a cohort of Japanese patients with revision TKA and (2) whether patient demographic features and underlying diagnosis of primary TKA are associated with the causes of revision TKA.

Methods

We assessed all revision TKA procedures performed at five major centers in Hokkaido from 2006 to 2011 for the causes of failures. Demographic data and underlying diagnosis for index primary TKA of the revision cases were compared to those of randomly selected primary TKAs during the same period.

Results

One hundred forty revision TKAs and 4047 primary TKAs were performed at the five centers, indicating a revision burden of 3.3%. The most common cause of revision TKA was mechanical loosening (40%) followed by infection (24%), wear/osteolysis (9%), instability (9%), implant failure (6%), periprosthetic fracture (4%), and other reasons (8%). The mean age of patients with periprosthetic fracture was older (77 versus 72 years) and the male proportion in patients with infection was higher (33% versus 19%) than those of patients in the primary TKA group. There was no difference in BMI between primary TKAs and any type of revision TKA except other causes.

Conclusions

The revision burden at the five referral centers in Hokkaido was 3.3%, and the most common cause of revision TKA was mechanical loosening followed by infection. Demographic data such as age and sex might be associated with particular causes of revision TKA.     

Is High Flexion Following Total Knee Arthroplasty Safe?: Evaluation of Knee Joint Loads in the Patients During Maximal Flexion

The purpose of this study was to indicate the mechanical loads and the flexion angle at the knee during rise from maximal flexion following total knee arthroplasty (TKA). Twenty three knees were evaluated using skin marker-based motion analysis system during four different activities of daily living. The average maximum flexion was 90 degrees (34 degrees less than passive flexion) and all subjects required support for their weight to rise from maximal flexion. The external moments and the external forces at the knee during the maximal flexion were smaller than those during the stair descending activity. The results indicate that capable flexion angle for the patients following TKA is approximately 90 degrees which has smaller mechanical loads at the knee than the stair descending activity.     

Do Porous Tantalum Metaphyseal Cones Improve Outcomes in Revision Total Knee Arthroplasty?

Background

Some authors have advocated for use of porous tantalum metaphyseal cones to manage bone defects during revision total knee arthroplasty (TKA). The purpose of this study is to compare results with porous metaphyseal cones to results with traditional hybrid stem fixation in revision TKA.

Revision of Unicompartmental to Total Knee Arthroplasty: Does the Unicompartmental Implant (Metal-Backed vs All-Polyethylene) Impact the Total Knee Arthroplasty?

Background

The aim of this study is to investigate differences in implant requirement, outcomes, and re-revision when total knee arthroplasty (TKA) was performed following unicompartmental knee arthroplasties (UKAs) with metal-backed (MB) compared to all-polyethylene (AP) tibial components.

How Accurate Is ICD-10 Coding for Revision Total Knee Arthroplasty?

BackgroundThe International Classification of Diseases-10 (ICD-10) came into effect in October 2015. The new procedural codes (ICD-10-PCS) were designed to specify granular aspects of the procedure, including laterality and revised components. This specificity could improve data collection in institutional databases, large registries, and administrative claims data. Given these possible applications, this study’s purpose was to assess the accuracy of ICD-10-PCS coding for revision total knee arthroplasty (rTKA).MethodsThis multicenter retrospective analysis utilized the rTKA databases at four academic medical centers for all aseptic rTKAs between October 1, 2015 and July 3, 2019. Operative reports were reviewed to determine laterality and revised components (tibial, femoral, liner, and patellar component), which were then compared with the ICD-10-PCS codes associated with the billing records. Proper coding required both component removal and replacement codes. The correct series of removal and replacement codes was determined using the American Joint Replacement Registry’s guidelines.ResultsIn total, 1906 rTKAs were examined, and 98.0% had at least one proper ICD-10-PCS code, indicating an rTKA had occurred. Coding for components replaced was correct in 76.3% of cases. When examining both removal and replacement codes, accuracy dropped to 57.0%.ConclusionNearly 25% of rTKA procedures were incorrectly coded for replaced components, and over 40% were incorrectly coded for removed and replaced components. ICD-10-PCS codes can accurately identify that an rTKA has occurred; however, the inaccuracy in identifying which specific components were revised should prompt further evaluation of the coding process before utilizing ICD-10-PCS codes to report granular rTKA data.Level of EvidenceIII, retrospective observational analysis.     

What Are the Indications for Implant Revision in Three-component Total Ankle Arthroplasty?

BackgroundGiven the increasing usage of total ankle arthroplasty (TAA), a better understanding of the reasons leading to implant revision and the factors that might influence those indications is necessary to identify at-risk patients.Question/purposesUsing a single-design three-component ankle prosthesis, we asked: (1) What is the cumulative incidence of implant revision at 5 and 10 years? (2) What are the indications for implant revision in our population? (3) What factors are associated with an increased likelihood of implant revision during the time frame in question?MethodsBetween 2003 and 2017, primary TAA using a single-design three-component ankle implant was performed by or under the supervision of the implant designer in 1006 patients (1074 ankles) aged between 17 and 88 years to treat end-stage ankle osteoarthritis. No other TAA systems were used during the study period at the investigators’ institution. In 68 patients with bilateral surgery, only the first TAA was considered. Of the patients treated with the study implant, 2% (16 of 1006) were lost to follow-up 5 to 14 years after TAA and were not known to have died or undergone revision, and 5% (55 of 1006) were deceased due to reasons unrelated to the procedure, leaving 935 patients for evaluation in this retrospective study. The mean (range) follow-up for the included patients was 8.8 ± 4.2 (0.2 to 16.8) years. Implant revision was performed 0.5 to 13.2 years after TAA in 12% (121 of 1006) of our patients. Survivorship free from revision was calculated using cumulative incidence (competing risks) survivorship, with death as a competing risk. The reason for each revision was classified into one of six categories according to a modified version of a previously published protocol: aseptic loosening, cyst formation, instability, deep infection, technical error, and pain without another cause. Two foot and ankle surgeons reviewed the records of all patients who underwent implant revision and assigned each patient’s reason for revision to one of the six categories. The decision for assigning each patient to one of the six categories was made based on a consensus agreement. A subgroup classification of preoperative ankle alignment (neutral, mild, and major deformity) and variables of age, sex, BMI, etiology of ankle osteoarthritis, and number of preoperative and intraoperative hindfoot or midfoot procedures were used in a multinomial logistic regression and Cox regression analysis to estimate their association with reason for revision and implant survival until revision.ResultsThe cumulative incidence of implant revision at the mean (range) follow-up time of 8.8 ± 4.2 years (0.2 to 16.8) was 9.8% (95% confidence interval 7.7% to 11.8%). Five and 10 years after TAA, cumulative incidence was 4.8% (95% CI 3.4 to 6.1) and 12.1% (95% CI 9.7% to 14.5%), respectively. The most common reason for revision was instability (34% [41 of 121]), followed by aseptic loosening of one or more metallic components (28% [34 of 121]), pain without another cause (12% [14 of 121]), cyst formation (10% [12 of 121]), deep infection (9% [11 of 121]), and technical error (7% [9 of 121]). Ankles with a major hindfoot deformity before TAA were more likely to undergo revision than ankles with a minor deformity (hazard ratio 1.9 [95% CI 1.2 to 3.0]; p = 0.007) or neutral alignment (HR 2.5 [95% CI 1.5 to 4.4]; p = 0.001). A preoperative hindfoot valgus deformity increased revision probability compared with a varus deformity (HR 2.1 [95% CI 1.4 to 3.4]; p = 0.001).ConclusionInstability was a more common reason for implant revision after TAA with this three-component design than previously reported. All causes inducing either a varus or valgus hindfoot deformity must be meticulously addressed during TAA to prevent revision of this implant. Future studies from surgeons/institutions not involved in this implant design are needed to confirm these findings and to further investigate why a substantial number of patients had pain of unknown cause prompting revision.Level of EvidenceLevel III, therapeutic study.     

Are Gender-Specific Femoral Implants for Total Knee Arthroplasty Necessary?

The purpose of this study was to determine the effect of gender on epiphyseal morphology and using this information to determine if an implant product line with a single width provides sufficient bone coverage for the entire population of knees being replaced. Morphology of the distal femoral epiphysis from 420 continuous knees was acquired with a surgical navigation system during primary TKA. A three-dimensional model of the distal femur was generated and used to determine the anterioposterior (AP) and mediolateral (ML) dimensions on 19 different virtual knee sections. Female knees had smaller AP and ML dimensions than male knees. The ML width of the distal femoral epiphysis was associated with femur length, not gender. Measurements derived from surgical navigation confirm that distal femoral epiphysis dimensions are related to femur length only independently of gender.     

Are Patient-specific Cutting Blocks Cost-effective for Total Knee Arthroplasty?

Background  

Using patient-specific cutting blocks for TKA increases the cost to the hospital for these procedures, but it has been proposed they may reduce operative times and improve implant alignment, which could reduce the need for revision surgery.     

Revision Surgery for Instability After Total Hip Arthroplasty: Does Timing Matter?

BackgroundInstability is a common reason for revision surgery after total hip arthroplasty (THA). Recent studies suggest that revisions performed in the early postoperative period are associated with higher complication rates. The purpose of this study is to assess the effect of timing of revision for instability on subsequent complication rates.MethodsThe Medicare Part A claims database was queried from 2010 to 2017 to identify revision THAs for instability. Patients were divided based on time between index and revision surgeries: <1, 1-2, 2-3, 3-6, 6-9, 9-12, and >12 months. Complication rates were compared between groups using multivariate analyses to adjust for demographics and comorbidities.ResultsOf 445,499 THAs identified, 9298 (2.1%) underwent revision for instability. Revision THA within 3 months had the highest rate of periprosthetic joint infection (PJI): 14.7% at <1 month, 12.7% at 1-2 months, and 10.6% at 2-3 months vs 6.9% at >12 months (P < .001). Adjusting for confounding factors, PJI risk remained elevated at earlier periods: <1 month (adjusted odds ratio [aOR]: 1.84, 95% confidence interval [CI]: 1.51-2.23, P < .001), 1-2 months (aOR: 1.45, 95% CI: 1.16-1.82, P = .001), 2-3 months (aOR: 1.35, 95% CI: 1.02-1.78, P = .036). However, revisions performed within 9 months of index surgery had lower rates of subsequent instability than revisions performed >12 months (aOR: 0.67-0.85, P < .050), which may be due to lower rates of acetabular revision and higher rates of head-liner exchange in this later group.ConclusionWhen dislocation occurs in the early postoperative period, delaying revision surgery beyond 3 months from the index procedure may be warranted to reduce risk of PJI.     

Is There a Place for Rotating-Hinge Arthroplasty in Knee Revision Surgery for Aseptic Loosening?

We reviewed the results of 78 revision total knee arthroplasties using a rotating-hinge device, performed from 1993 through 2002. The average follow-up was 7.83 years. Only patients requiring revision arthroplasty due to aseptic loosening were included. Reasons for revision were malalignment with or without polyethylene wear (47), instability (24), extensor mechanism failure (3), and periprosthetic fracture (4). The mean preoperative scores according to the American Knee Society rating scale was 37.5 points for knee score and 32.8 points for function score. Postoperatively, the knee score improved to 85.7 points and the function score improved to 61.4 points. Nineteen patients had complications related to the design prostheses (mostly minor complications). Fifty-seven patients (73%) had excellent results, with a range of motion of 104 degrees in flexion and complete extension. For extreme circumstances, such as gross instability of the medial collateral ligament, massive bone loss, comminuted fracture, and chronic dysfunction of the extensor mechanism, there is a place for hinged revision implant surgery with good clinical results and quality of life.     

Are Patients With a History of Septic Arthritis Undergoing Total Knee Arthroplasty at Higher Risk for Revision Surgery? A Single-Center Study

BackgroundThe decision to perform a total knee arthroplasty (TKA) on a previously infected knee is made complicated by the higher risk for both a periprosthetic joint infection (PJI) and early failure. There is currently no standard in the treatment strategy for this group of patients. We here report the outcomes of performing a primary TKA on patients with a prior septic knee arthritis. The aim of our study is to analyze the survival rates of patients with a history of septic arthritis undergoing TKA.MethodsFrom 2010 to 2018, all patients treated in our institution with a minimum follow-up of 1 year, who have previous histories of knee joint infections and underwent a primary TKA were included in the study. All patients underwent the same surgical protocol and were given systemic and local antibiotic treatment.ResultsOf the 68 knees, there were 4 surgical revisions (5.9%). These included 2 septic revisions due to PJI (2.9%), 1 open arthrolysis for arthrofibrosis (1.5%), and 1 aseptic revision for implant loosening (1.5%). Sixty-four (64) knees (94%) had survived without any surgical interventions and the Kaplan-Meier analysis demonstrated an overall survivorship free from PJI of 97.1% at a mean of 5 years (range 1-9, standard deviation ±2.5 years).ConclusionTKA is a suitable option for patients with a prior septic arthritis of the knee, provided that proper surgical technique and the utilization of systemic and local antibiotics are employed.Level of EvidenceLevel III, therapeutic study.     

Are Patients Being Appropriately Selected for Same-Day Discharge Total Knee Arthroplasty?

BackgroundDecreased cost associated with same-day discharge (SDD) total knee arthroplasty (TKA) has led to an increased interest in this topic. The purpose of this study is to investigate whether there is a population of TKA patients in which SDD has similar rates of 30-day complications compared to patients discharged on postoperative day 1 or 2.MethodsUsing the American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2018, 6,327 TKA patients who had a SDD (length of stay [LOS] = 0) were matched to TKA patients who had an LOS of 1 or 2 days. All SDD patients were successfully matched 1:1 using the morbidity probability variable (a composite variable of demographics, comorbidities, and laboratory values). Patients were divided into quartiles based on their morbidity probability. Bivariate logistic regressions were then used to compare any complication and major complication rates in the SDD quartiles to the corresponding quartiles with an LOS of 1 or 2 days.ResultsWhen comparing the 1st quartiles (healthiest), there was no difference between the cohorts in any complication (odds ratio [OR] = 0.960, 95% CI 0.552-1.670, P = .866) and major complications (OR = 0.999, 95% CI = 0.448-2.231, P = .999). The same was observed in quartile 2 (any complications: OR = 1.161, 95% CI = 0.720-1.874, P = .540). Comparing the third quartiles, there was an increase in all complications with SDD (OR = 1.784, 95% CI = 1.125-2.829, P = .014), but no difference in major complications (OR = 1.635, 95% CI = 0.874-3.061, P = .124). Comparing the fourth quartiles (least healthy), there was an increase in all complications (OR = 1.384, 95% CI = 1.013-1.892, P = .042) and major complications (OR = 1.711, 95% CI = 1.048-2.793, P = .032) with SDD.ConclusionThe unhealthiest 50% of patients in this study who underwent SDD TKA were at an increased risk of having any complication, calling into question the current state of patient selection for SDD TKA.Level of EvidenceIII.