What's New in Adult Reconstructive Knee Surgery.

What's New in Adult Reconstructive Knee Surgery.

Medial unicompartmental knee arthroplasties (UKAs) have good clinical outcomes but implant survival is inferior to that of total knee arthroplasties (TKAs). Conversion to a TKA is a reliable option when UKA fails. However, there is controversy regarding these conversions. The aim of this study was to analyze the survival of TKAs converted from UKAs when compared with both primary and revision TKAs. On the basis of registrations in the Danish Knee Arthroplasty Registry from 1997 to 2017, 1,012 TKAs converted from UKAs were compared with 73,819 primary TKAs and 2,572 revision TKAs. The primary outcome was the risk of revision. Secondarily, the study analyzed the influence of different implants, the indication for the UKA conversion, and surgical volume on the survival of TKA converted from UKA. Third, the study compared the indications for revision. The converted UKAs were mainly mobile-bearing (85%) and, at the time of conversion, the patients were younger (mean [standard deviation], 66 ± 10 years) and more were Charnley class A (55%) compared with patients with primary TKA (70 ± 9 years and 35% class A) or revision TKA (70 ± 10 years and 42% class A) (all p < 0.001). The survival of TKAs converted from UKAs was comparable with that of revision TKAs (p = 0.42) and significantly inferior to the survival of primary TKAs (p < 0.001). This relationship was unaffected by differences between the groups, with an adjusted hazard ratio of 0.94 (95% confidence interval [CI]: 0.74 to 1.19) compared with revision TKAs and 3.00 (95% CI: 2.47 to 3.66) compared with primary TKAs. The survival of TKA converted from UKA was unaffected by differences in the conversion implants (all p ≥ 0.47), experience with revision surgery (all p ≥ 0.06), and the indications for the UKA-to-TKA conversion (all p ≥ 0.27). Instability (26%) and unexplained pain (13%) were more frequent indications for revisions of TKA converted from UKA (p < 0.001). TKA converted from medial UKA has a 3-fold higher risk of revision when compared with primary TKA. The implant survival resembled that of revision TKA but with a higher prevalence of unexplained pain and instability. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

What's New in Hip Replacement.

As rates of primary total joint arthroplasty continue to rise, so do rates of revision. Revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) are more frequently done at larger centers, are associated with higher morbidity, and may have different patient satisfaction outcomes. This study compares the survey results of Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) between patients who underwent primary versus revision THA or TKA. All adult patients who underwent inpatient, elective, primary, and revision THA or TKA at a single institution were selected for retrospective analysis. Patient demographics, comorbidities, functional status, surgical variables, 30-day outcomes, and HCAHPS scores were assessed. Univariate and multivariate analyses were done to determine correlations between the aforementioned variables and top-box HCAHPS survey scores for primary versus revision THA and TKA. Of 2,707 patients who met the inclusion criteria and had returned the HCAHPS survey, primary THA was documented in 1,075 patients (39.71%), revision THA in 75 (2.77%), primary TKA in 1,497 (55.30%), and revision TKA in 60 (2.22%). Revision THA patients were more functionally dependent, and TKA patients had higher American Society of Anesthesiologists score than their primary comparators. Revisions had longer hospital length of stay for both procedures. For THA, revision THA patients demonstrated lower total top-box rates compared withprimary THA patients (71.64% versus 75.67% top-box, P < 0.001) and lower scores on the care from doctors subsection (76.26% versus 85.34%, P < 0.001) of the HCAHPS survey. Similarly, for TKA, revision TKA patients demonstrated lower total top-box rates (76.13% versus 79.22%, P < 0.013) and lower scores on the care from doctors subsection (66.28% versus 83.65%, P < 0.001) of the HCAHPS survey. For both THA and TKA, revision procedures were associated with lower total HCAHPS scores and rated care from doctors. This suggests that HCAHPS scores may be biased by factors outside the surgeon's control, such as the complexity associated with revision procedures. Level III.

Highlights of the 2021 American Joint Replacement Registry Annual Report.

The aim of this study was to determine the prevalence of depressive and anxiety disorders prior to total hip (THA) and total knee arthroplasty (TKA) and to assess their impact on the rates of any infection, revision, or reoperation. Between January 2000 and March 2019, 21,469 primary and revision arthroplasties (10,011 THAs; 11,458 TKAs), which were undertaken in 15,504 patients at a single academic medical centre, were identified from a 27-county linked electronic medical record (EMR) system. Depressive and anxiety disorders were identified by diagnoses in the EMR or by using a natural language processing program with subsequent validation from review of the medical records. Patients with mental health diagnoses other than anxiety or depression were excluded. Depressive and/or anxiety disorders were common before THA and TKA, with a prevalence of 30% in those who underwent primary THA, 33% in those who underwent revision THA, 32% in those who underwent primary TKA, and 35% in those who underwent revision TKA. The presence of depressive or anxiety disorders was associated with a significantly increased risk of any infection (primary THA, hazard ratio (HR) 1.5; revision THA, HR 1.9; primary TKA, HR 1.6; revision TKA, HR 1.8), revision (THA, HR 1.7; TKA, HR 1.6), re-revision (THA, HR 2.0; TKA, HR 1.6), and reoperation (primary THA, HR 1.6; revision THA, HR 2.2; primary TKA, HR 1.4; revision TKA, HR 1.9; p < 0.03 for all). Patients with preoperative depressive and/or anxiety disorders were significantly less likely to report "much better" joint function after primary THA (78% vs 87%) and primary TKA (86% vs 90%) compared with those without these disorders at two years postoperatively (p < 0.001 for all). The presence of depressive or anxiety disorders prior to primary or revision THA and TKA is common, and associated with a significantly higher risk of infection, revision, reoperation, and dissatisfaction. This topic deserves further study, and surgeons may consider mental health optimization to be of similar importance to preoperative variables such as diabetic control, prior to arthroplasty.

Few large-scale studies using adjusted data from national registries have explored the risk factors of subsequent revision in patients with unicompartmental knee arthroplasty (UKA) compared to those with total knee arthroplasty (TKA). We investigated the incidence rate and risk factors of subsequent revision in patients with UKA and TKA. We enrolled all patients who had undergone TKA or UKA as the primary surgical procedure without histories of having undergone either procedure during the preceding 2years. Matched Cox regression models were used to compare the risks of revision between groups after propensity score matching. Revision was defined as conversion to revision TKA after primary TKA and conversion to TKA after UKA. The study enrolled 418,806 TKA patients and 446,009 UKA patients. The risk of revision during the entire study period was higher for patients with UKA than for patients with TKA (adjusted hazard ratio [HR] 1.22, 95% confidence interval [95% CI]: 1.10-1.36). The Kaplan-Meier 8-year survival was 98.7% in the TKA group and 96.7% in the UKA group. Patients with UKA were at an increased risk of revision in cases of advanced age (70-79years, HR 1.40, 95% CI: 1.15-1.71), female sex (HR 1.32, 95% CI: 1.16-1.49), the presence of chronic obstructive pulmonary disease (COPD) (HR 1.27, 95% CI: 1.05-1.54), the presence of peptic ulcer disease (PUD) (HR 1.34, 95% CI: 1.11-1.61) compared to patients with TKA. In patients with hemiplegia, however, UKA were associated with a lower risk of subsequent revision (HR 0.25, 95% CI: 0.07-0.94). The risk of a complete exchange or failure was higher for patients with UKA than for patients with TKA. The most significant independent risk factors for subsequent a complete exchange or failure in patients with UKA were advanced age (70-79years), female sex, and the presence of comorbidities such as COPD and PUD.

Revision Unicompartmental Knee Arthroplasty: Worse than a Primary, but Better than a Revision Total Knee Arthroplasty.

In this issue of The BJJ, we have two specialty updates in knee surgery that will be of interest to clinicians all around the world. Jonathan Eldridge and his team provide a clear perspective on adolescent patellar instability – a problem with many variations and even more solutions.[1][1] Wang

Unicompartmental knee arthroplasty (UKA) has a higher risk of revision than total knee arthroplasty (TKA), particularly for younger patients. The outcome of knee arthroplasty is typically defined as implant survival or revision incidence after a defined number of years. This can be difficult for patients to conceptualize. We aimed to calculate the 'lifetime risk' of revision for UKA as a more meaningful estimate of risk projection over a patient's remaining lifetime, and to compare this to TKA. Incidence of revision and mortality for all primary UKAs performed from 1999 to 2019 (n = 13,481) was obtained from the New Zealand Joint Registry (NZJR). Lifetime risk of revision was calculated for patients and stratified by age, sex, and American Society of Anesthesiologists (ASA) grade. The lifetime risk of revision was highest in the youngest age group (46 to 50 years; 40.4%) and decreased sequentially to the oldest (86 to 90 years; 3.7%). Across all age groups, lifetime risk of revision was higher for females (ranging from 4.3% to 43.4% vs males 2.9% to 37.4%) and patients with a higher ASA grade (ASA 3 to 4, ranging from 8.8% to 41.2% vs ASA 1 1.8% to 29.8%). The lifetime risk of revision for UKA was double that of TKA across all age groups (ranging from 3.7% to 40.4% for UKA, and 1.6% to 22.4% for TKA). The higher risk of revision in younger patients was associated with aseptic loosening in both sexes and pain in females. Periprosthetic joint infection (PJI) accounted for 4% of all UKA revisions, in contrast with 27% for TKA; the risk of PJI was higher for males than females for both procedures. Lifetime risk of revision may be a more meaningful measure of arthroplasty outcomes than implant survival at defined time periods. This study highlights the higher lifetime risk of UKA revision for younger patients, females, and those with a higher ASA grade, which can aid with patient counselling prior to UKA. Cite this article: Bone Joint J2022;104-B(6):672-679.

Knee arthroplasty has emerged as an effective treatment for end-stage gonarthrosis. Although total knee arthroplasty remains the gold standard, unicompartmental knee arthroplasty is an appropriate alternative for select patients. We sought to use a large, heterogeneous national database to identify differences in thirty-day complication rates between unicompartmental and total knee arthroplasty as well as to identify risk factors for complications. Patients in the ACS NSQIP (American College of Surgeons National Surgical Quality Improvement Program) database who had undergone total or unicompartmental knee arthroplasty from 2005 to 2011 were identified. CPT (Current Procedural Terminology) codes were used to select cases of elective primary knee arthroplasty. Statistical models employing univariate and multivariate logistic regression identified risk factors associated with the thirty-day incidence of morbidity and mortality after total and unicompartmental knee arthroplasty. Propensity score matching addressed demographic differences between the total and unicompartmental knee arthroplasty cohorts. A total of 29,333 patients were identified; 27,745 (94.6%) underwent total knee arthroplasty and 1588 (5.41%) underwent unicompartmental knee arthroplasty. Prior to matching, the total knee arthroplasty cohort was 63.7% female and had a mean BMI of 32.8 ± 7.3 kg/m(2), whereas the values for the unicompartmental cohort were 55.3% and 31.5 ± 6.5 kg/m(2) (p < 0.0001). The mean ages of these cohorts were 67.2 ± 10.1 and 64.0 ± 10.7 years, respectively (p < 0.0001). A previously developed and implemented propensity score matching algorithm was used to address the demographic differences. Following matching, the total complication rate did not differ significantly between the total and unicompartmental knee arthroplasty cohorts (5.29% compared with 4.16%, p = 0.35), whereas the rate of deep venous thrombosis (1.50% compared with 0.50%, p = 0.02) and the duration of hospital stay (3.4 compared with 2.2 days, p < 0.0001) were significantly higher in the total knee arthroplasty cohort. Comparison of total and unicompartmental knee arthroplasty revealed no differences in overall short-term (thirty-day) morbidity and mortality. Although this study does not address long-term subjective outcomes or implant survival, these findings should provide helpful information for surgeons counseling patients considering total and/or unicompartmental knee arthroplasty. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Migration Patterns for Revision Total Knee Arthroplasty in the United States as Reported in the American Joint Replacement Registry

Differences in Risk of Revision and Mortality Between Total and Unicompartmental Knee Arthroplasty. The Influence of Hospital Volume

National trends in total and unicompartmental knee arthroplasty: 2020 to 2022.

This study aimed to compare the cost profiles of patients who underwent a primary or revision total knee arthroplasty (TKA) and to determine the effects of the length of hospital stay, comorbidities, and septic and aseptic revision rates on the treatment costs. A total of 1,487 patients who underwent primary (n=1,328; 1,131 females, 197 males) or revision TKA (n=159; 137 females, 22 males) between 2010 and 2017 at our institution were retrospectively included in the current study. The patients' demographics (age and gender), the length of hospital stay, comorbidities, and septic and aseptic revision rates were collected from our hospital database. The total costs of revision and primary TKAs were calculated based on the prostheses and surgical equipment used, hospital stay, and other administrative costs in both the Turkish lira (TRY) and US dollar (USD) based on the parity of the 2 currencies from 2010 to 2017. The average cost per patient for primary TKAs was 7,985±2,927 TRY (5,265 USD) in 2010 and 7,070±1,775 TRY (1,852 USD) in 2017. The average cost for revision TKAs was 13,647±4,095 TRY (8,999 USD) in 2010 and 22,806±6,155 TRY (5,973 USD) in 2017. In terms of the total costs, significant differences existed over the years, with a significantly higher difference in 2015 compared with that from 2010 to 2013 (p<0.001); however, no difference was determined among the age groups (p=0.675). The difference between the total costs of the septic (n=34; 17,964±13,028 TRY) and aseptic revisions (n=125; 23,377±12,815 TRY) was significant (p=0.001), with a higher cost for patients with septic TKAs but with no significant difference between the total costs for the patients with and without comorbidities (p=0.254). Additionally, the length of hospital stay was 2 times higher in patients with revision TKAs than in those with primary TKAs (12.3 vs 6.2 days). Revision TKAs cause higher costs than primary TKAs, with a prolonged hospital stay. The septic background seems to be an independent predictive factor for increased costs in revision TKAs.