What Are the All-Cause Survivorship Rates and Functional Outcomes in Patients Younger Than 55 Years Undergoing Primary Knee Arthroplasty? A Systematic Review

Return to Sports After Unicompartmental Knee Arthroplasty

Knee osteoarthritis (OA) is a widespread and potentially debilitating condition that can interfere with the growing demand for a healthy and active lifestyle. In people under the age of 55 years, the prevalence of OA is expected to increase substantially in the coming decades. High tibial osteotomy and cartilage repair operations have been used to treat OA in young, active individuals; however, these procedures require lengthy rehabilitation periods and result in poor return to preoperative levels of activity that make them unsuitable for the young, active patient. Unicompartmental knee arthroplasty (UKA) is a less invasive treatment alternative, especially for younger, active, middle-aged persons with a desire to return to sporting activities. UKA yields successful return to activities with excellent functional outcomes and mid- to long-term survivorship. This article will review the ability of patients to return to sports after UKA, the type and nature of the sporting activities, as well as the timing to return to these sports.

Is Younger Age a Risk Factor for Failure Following Aseptic Revision Total Knee Arthroplasty?

BACKGROUND

Revision total knee arthroplasties (rTKAs) are being performed more frequently in the United States in younger patients. Few large studies have evaluated the effect of age following rTKA. The study sought to evaluate the effect of age on rTKA outcomes.

METHODS

The American Joint Replacement Registry was used to identify aseptic rTKAs in younger (18 to 64 years, n = 32,631) and older (> 65 years, n = 43,992) patients from January 2012 to September 2020, allowing for a minimum 2-year follow-up. The mean age was 56 years in the younger cohort and 73 years in the older cohort. The mean follow-up was 5.4 years. Sex and body mass index were similar between groups. Kaplan-Meier survivorship analysis was performed with rerevision as the primary endpoint. Secondarily, multivariate analyses were performed to adjust for demographics and comorbidities.

RESULTS

The proportion with rerevision was higher in the younger cohort compared to the older (8.1 versus 5.4%, P < 0.001). The 10-year survivorship free of all-cause rerevision was 90.2% (95% confidence interval [CI]: 89.7 to 90.7) in the younger cohort versus 93.7% (95% CI: 93.4 to 94.1) in the older cohort (P < 0.0001). Younger age was significantly associated with a higher adjusted hazard ratio (HR) for all-cause rerevision (HR: 1.4, 95% CI: 1.3 to 1.6), as were men (HR: 1.4, 95% CI: 1.2 to 1.5) and initial revision for instability (HR: 1.3, 95% CI: 1.1 to 1.5). In a subgroup analysis of patients aged < 65 years, a 5-year decrease in age was associated with a 10.0% increase in risk of rerevision. Indications for rerevisions differed among the younger and older cohorts (P < 0.01): infection (30.2 versus 34.9%), aseptic loosening (19.0 versus 15.8%), and instability (12.2 versus 12.7%).

CONCLUSIONS

Younger age, men, and initial revision performed for instability were associated with significantly increased risk for all-cause rerevision following aseptic rTKA. Notably, age may have a continuous effect on rerevision rates, as each 5-year decrease in age was associated with a 10% increase in risk of rerevision. Future research may further elucidate these increased risks in this younger patient population.

Association Between Digitally Provided Education and 90-Day Return to Sexual Activity Following Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Contemporary total knee arthroplasty patients have increased expectations of returning to predisease function, including sexual activity (SA). The purpose of this study was to determine whether patients using a digital care management platform (DCMP) were more likely to have a higher rate and frequency of return to SA.

METHODS

We conducted an exploratory analysis of a prospective, multicenter, randomized controlled trial that enrolled patients undergoing total knee arthroplasty. A total of 304 patients were randomized to a DCMP (n = 119) providing preoperative and postoperative education regarding return to SA or standard postoperative care (control group; n = 185). Return to SA, assessed via questionnaire, patient-reported outcome measures, Timed Up and Go test, single leg stance, active range of motion and need for manipulation under anesthesia were assessed at 90 days postoperatively.

RESULTS

More patients in the DCMP group returned to SA compared to control at 90 days (58.4 versus 39.6%, P = .018); however, the control group resumed SA sooner (33.1 versus 42.0 days, P = .023). Patients who returned to SA were younger (61.6 versus 65.9 year), more often men (56 versus 35%) (P < .001), higher performing on the Timed Up and Go and single leg stance tests (P < .001), and had greater active range of motion (P = .007). There were no differences in patient-reported outcome measures or need for manipulation under anesthesia between patients that returned to SA and those who did not.

CONCLUSIONS

More patients using a DCMP resumed SA at 90 days; however, patients in the control group returned to SA sooner. Those who returned to SA were younger, possessed greater physical function, and were more often men.

[Evolving indications for partial knee replacement : New aspects]

BACKGROUND

Partial knee replacement has proven to be an effective therapy for advanced unicompartmental arthrosis of the knee. Despite continuous advancements in implants and surgical techniques over the past decades, the global preference for total knee arthroplasty still persists for historical reasons.

OBJECTIVES

This report aims to illuminate advantages and disadvantages of partial knee replacement considering long-term results, the evolution of indication criteria over recent decades and new aspects in patient selection with potential improvements through emerging technologies.

MATERIAL AND METHODS

The analysis involves the examination of long-term results from clinical studies and registry data, highlighting the risk factors for potential failures and their influence on the development of indication criteria.

RESULTS

Present-day long-term results demonstrate excellent prosthetic survival, aligning with outcomes from total knee arthroplasty. New perspectives for expanding indication criteria are discussed, including the possible application of partial knee replacement in cases of severe varus deformity > 15°, anterior cruciate ligament insufficiency, young active patients, anterior knee pain, and/or patellofemoral arthritis, as well as mild radiographic arthritis with degenerative medial meniscus root tear and meniscal extrusion.

DISCUSSION

Indication criteria have consistently expanded in recent years, taking into account modern insights, and the application of advanced technologies can enhance precision and minimize surgical errors. Furthermore, this report emphasizes that revision rates are not the sole criterion for success and underscores the necessity for a comprehensive examination of clinical results.

Younger Patients Undergoing Total Ankle Arthroplasty Experience Higher Complication Rates and Worse Functional Outcomes

BACKGROUND

Although many patients with posttraumatic ankle arthritis are of a younger age, studies evaluating the impact of age on outcomes of primary total ankle arthroplasty (TAA) have revealed heterogenous results. The purpose of the present study was to determine the effect of age on complication rates and patient-reported outcomes after TAA.

METHODS

We retrospectively reviewed the records of 1,115 patients who had undergone primary TAA. The patients were divided into 3 age cohorts: <55 years (n = 196), 55 to 70 years (n = 657), and >70 years (n = 262). Demographic characteristics, intraoperative variables, postoperative complications, and patient-reported outcome measures were compared among groups with use of univariable analyses. Competing-risk regression analysis with adjustment for patient and implant characteristics was performed to assess the risk of implant failure by age group. The mean duration of follow-up was 5.6 years.

RESULTS

Compared with the patients who were 55 to 70 years of age and >70 years of age, those who were <55 years of age had the highest rates of any reoperation (19.9%, 11.7%, and 6.5% for the <55, 55 to 70, and >70-year age groups, respectively; p < 0.001), implant failure (5.6%, 2.9%, and 1.1% for the <55, 55 to 70, and >70-year age groups, respectively; p = 0.019), and polyethylene exchange (7.7%, 4.3%, and 2.3% for the <55, 55 to 70, and >70-year age groups, respectively; p = 0.021). Competing-risk regression revealed a decreased risk of implant failure for patients who were >70 of age compared with those who were <55 years of age (hazard ratio [HR], 0.21 [95% confidence interval (CI), 0.05 to 0.80]; p = 0.023) and for patients who were 55 to 70 years of age compared with those who were <55 years of age (HR, 0.35 [95% CI, 0.16 to 0.77]; p = 0.009). For all subscales of the Foot and Ankle Outcome Score (FAOS) measure except activities of daily living, patients who were <55 years of age reported the lowest (worst) mean preoperative and postoperative scores compared with those who were 55 to 70 years of age and >70 years of age (p ≤ 0.001). Patients who were <55 years of age had the highest mean numerical pain score at the time of the latest follow-up (23.6, 14.4, 12.9 for the <55, 55 to 70, and >70-year age groups, respectively; p < 0.001).

CONCLUSIONS

Studies involving large sample sizes with intermediate to long-term follow-up are critical to reveal age-related impacts on outcomes after TAA. In the present study, which we believe to be the largest single-institution series to date evaluating the effect of age on outcomes after TAA, younger patients had higher rates of complications and implant failure and fared worse on patient-reported outcome measures.

LEVEL OF EVIDENCE

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

No exponential rise in revision knee replacement surgery over the past 15 years: an analysis from the National Joint Registry

OBJECTIVE

To investigate trends in the incidence rate and the main indication for revision knee replacement (rKR) over the past 15 years in the UK.

METHOD

Repeated national cross-sectional study from 2006 to 2020 using data from the National Joint Registry (NJR). Crude incidence rates were calculated using population statistics from the Office for National Statistics.

RESULTS

Annual total counts of rKR increased from 2,743 procedures in 2006 to 6,819 procedures in 2019 (149% increase). The incidence rate of rKR increased from 6.3 per 100,000 adults in 2006 (95% CI 6.1 to 6.5) to 14 per 100,000 adults in 2019 (95% CI 14 to 14) (122% increase). Annual increases in the incidence rate of rKR became smaller over the study period. There was a 43.6% reduction in total rKR procedures in 2020 (during the Covid-19 pandemic) compared to 2019. Aseptic loosening was the most frequent indication for rKR overall (20.7% procedures). rKR for aseptic loosening peaked in 2012 and subsequently decreased. rKR for infection increased incrementally over the study period to become the most frequent indication in 2019 (2.7 per 100,000 adults [95% CI 2.6 to 2.9]). Infection accounted for 17.1% first linked rKR, 36.5% second linked rKR and 49.4% third or more linked rKR from 2014 to 2019.

CONCLUSIONS

Recent trends suggest slowing of the rate of increase in the incidence of rKR. Infection is now the most common indication for rKR, following recent decreases in rKR for aseptic loosening. Infection was prevalent in re-revision KR procedures.

The Performance of Diagnostic Tests for Identifying Periprosthetic Joint Infection After Failed Partial Knee Arthroplasty

BACKGROUND

Indications for unicompartmental knee arthroplasty (UKA) and patello-femoral arthroplasty are expanding. Despite the lower published infection rates for UKA and patello-femoral arthroplasty than total knee arthroplasty, periprosthetic joint infection (PJI) remains a devastating complication and diagnostic thresholds for commonly utilized tests have not been investigated recently. Thus, this study evaluated if diagnostic thresholds for PJI in patients who had a failed partial knee arthroplasty (PKA) align more closely with previously reported thresholds specific to UKA or the 2018 International Consensus Meeting on Musculoskeletal Infection.

METHODS

We identified 109 knees in 100 patients that underwent PKA with eventual conversion to total knee arthroplasty within a single healthcare system from 2000 to 2021. Synovial fluid nucleated cell count and synovial polymorphonuclear percentage in addition to preoperative serum erythrocyte sedimentation rate, serum C-reactive protein, and serum white blood cell count were compared with Student's t-tests between septic and aseptic cases. Receiver operating characteristic curves and Youden's index were used to assess diagnostic performance and the optimal cutoff point of each test.

RESULTS

Synovial nucleated cell count, synovial polymorphonuclear percentage, and serum C-reactive protein demonstrated excellent discrimination for diagnosing PJI with an area under the curve of 0.97 and lower cutoff values than the previously determined UKA specific criteria. Serum erythrocyte sedimentation rateESR demonstrated good ability with an area under the curve of 0.89.

CONCLUSION

Serum and synovial fluid diagnostic thresholds for PJI in PKAs align more closely with the thresholds established by the 2018 International Consensus Meeting as compared to previously proposed thresholds specific to UKA.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Knee arthroplasty utilization trends from 2010 to 2019

BACKGROUND

Interest in partial knee arthroplasty procedures including unicompartmental arthroplasty (UKA), patellofemoral arthroplasty (PFA), and bicompartmental knee arthroplasty (BKA) has increased due to their bone and ligament preservation compared to total knee arthroplasty (TKA). Implant designs, changing thoughts on appropriate indications for partial knee arthroplasty, and availability of navigation also impacted the field over the last decade. The aims of this study were to evaluate trends over the last decade in utilization of 1) partial and total knee arthroplasty; and 2) computer-assistance in knee arthroplasty.

METHODS

A retrospective cohort analysis was conducted using the PearlDiver database. Patients who underwent PFA, UKA, BKA, and TKA for an indication of osteoarthritis (OA) were identified using Current Procedural Terminology (CPT) codes. Trends analysis from 2010 to 2019 was conducted to compare utilization based on procedure type and computer-assistance. Statistical analysis was conducted using Compounded Annual Growth Rates (CAGR) and linear regression.

RESULTS

From 2010 to 2019, there was a significant decrease in utilization of PFA (CAGR: -5.73 %; p = 0.011) and BKA (CAGR: -10.49 %; p = 0.013), but no significant difference in that of UKA (p = 0.224) and TKA (p = 0.421). There was a significant increase in the utilization of computer assistance for both UKA (CAGR: +19.81 %; p = 0.002) and TKA (CAGR: +3.90 %; p = 0.038), but there was no significant difference for computer-assisted PFA (p = 0.724) and BKA (p = 0.951).

CONCLUSIONS

TKA is still the most common arthroplasty procedure for OA. Decreased utilization of PFA and BKA may be explained by reported failure and revision rates for PFA and BKA compared to TKA.

Effect of tibial component overhang on survivorship in medial mobile-bearing unicompartmental knee arthroplasty

BACKGROUND

Some studies have shown that the position of the tibial component in Oxford unicompartmental knee arthroplasty with a mobile bearing will affect the clinical outcome of patients. Hence, our study aimed to investigate the relationship between the overhang distance of the tibial component and the survival of the implant.

METHODS

A retrospective analysis of patients who underwent unicompartmental knee arthroplasty at the same institution from 2014 to 2018 was presented. The study was divided into three groups: minor underhang group (underhang between -3 and 0 mm); minor overhang group (overhang 0-3 mm); and major overhang group (overhang ≥ 3 mm). Demographic and clinical profile characteristics of each group were compared, and survival curves of each group were also compared using Kaplan-Meier and modeled using multivariate Cox regression.

RESULTS

A total of 351 knees were included in this study with a minimum follow up of three years and a mean follow up of 4.8 ± 1.5 years. The revision rates in each group were 3.6% (minor underhang group), 2.7% (minor overhang group), and 20.9% (major overhang group) (P < 0.001). From the three groups' cumulative survival rates, the major overhang group was significantly lower than the other two groups (log rank P < 0.001). Multivariate Cox regression showed an association between the major overhang group and implant survival rate (hazard ratio = 7.515, 95% confidence interval = 2.500-22.593, P < 0.001) CONCLUSION: The risk of revision will increase if the tibial component overhangs more than 3 mm medially. Moreover, the reasons for revision are generally bearing dislocation and aseptic loosening.