Risk factors for revision of total knee arthroplasty: a scoping review

Postoperative Vitamin D Surveillance and Supplementation in Revision Total Knee Arthroplasty Patients: A Retrospective Cohort Analysis

This study was a retrospective cohort analysis of 20 patients who underwent 23 revision total knee arthroplasty procedures in a single geographic region of the United States from January 2015 to February 2023. We analyzed their 25-OH vitamin D levels preoperatively and postoperatively at 1 month, 3 months, 6 months, 1 year, and 2 years. We categorized their supplementation regimens by dose: none, low dose (1000 IU and below), medium dose (1001-5000 IU), and high dose (>5000 IU). We found that there was a high incidence of vitamin D deficiency in this patient population.

A Polished Cobalt-Chrome Baseplate is not Associated With a Lower Revision Rate Than Matt Titanium in a Single Total Knee Arthroplasty Implant System With Identical Baseplate Design

BACKGROUND

Polished baseplates were introduced into total knee arthroplasty (TKA) systems to reduce the incidence of backside wear. In 2004, a fixed-bearing knee arthroplasty system underwent a change in baseplate material from matt titanium to polished cobalt-chrome (CoCr) with the intention to reduce backside wear. Other design aspects were left unchanged. The aim of this study was to compare these implants with each baseplate using data from the Australian Orthopaedic Association National Joint Replacement Registry.

METHODS

Primary TKA procedures performed between January 2010 and December 2021 for osteoarthritis, using a single design with cross-linked polyethylene inserts and matt titanium or polished CoCr baseplates, were analyzed. The primary outcome was all-cause revision, summarized using Kaplan-Meier estimates, with age- and sex-adjusted hazard ratios estimated from Cox proportional hazards models. In total, there were 2,091 procedures with matt titanium and 2,519 procedures with polished CoCr baseplates.

RESULTS

The 9-year cumulative percent revision was 2.5% (95% confidence interval [CI] 1.8 to 3.5%) and 4.2% (95% CI 3.1 to 5.6%) for the matt titanium and CoCr groups, respectively. Compared to matt titanium, the revision rate of CoCr baseplates was not significantly higher (hazard ratio 1.44; 95% CI 0.96 to 2.15; P = .076).

CONCLUSIONS

Polished CoCr baseplates in a single TKA system were not associated with reduced all-cause revision rates compared to matt titanium up to 11 years post-TKA. Our results suggest that the predicted reduction in wear particle debris production from polished CoCr baseplates may not correlate with reduced revision rates in vivo, but further evaluation is required.

Predictors of Undergoing Revision Within 5 Years of Total Knee Arthroplasty: A Population-Based Study

BACKGROUND

The objective of this study was to identify the rate and risk factors for revision total knee arthroplasty (TKA) within the first 5 years postoperative. Our secondary objective was to identify the rate of additional surgical procedures and death.

METHODS

We conducted a retrospective cohort study among patients in Ontario, Canada who underwent an elective, primary TKA between April 1, 2007, and March 31, 2014, for osteoarthritis. We excluded patients under 40 years and who had undergone a TKA within the previous 15 years. Our final study cohort included 94,193 patients. We reported the proportion of the study cohort who experienced revision surgery within 2 and 5 years of the primary TKA; secondary surgery within 5 years. We conducted Cochran-Armitage tests for trends to assess changes in the proportion of patients who experienced each of the study outcomes, and multivariable logistic regressions to evaluate predictors of a revision TKA.

RESULTS

There were 3,112 (3.3%) patients who had a revision within 5 years, and 1,866 (2.0%) within 2 years of their primary TKA. 3,316 (3.5%) had a secondary surgery (0.6% patellar resurfacing; 1.6% manipulation; 1.3% synovectomy; 0.5% washout; 0.9% debridement). Lower age, men, lower income, higher comorbidity score, depression, previous arthroscopy, lower surgeon volume, and general anesthesia were all significant positive predictors of revision.

CONCLUSIONS

In our study cohort, 2.0% of patients had a revision TKA within 2 years, and 3.3% within 5 years of their primary TKA. Preoperative identification of risk factors may reduce the future prevalence of revision TKAs.

Smoking is associated with higher short-term risk of revision and mortality following primary hip or knee arthroplasty: a cohort study of 272,640 patients from the Dutch Arthroplasty Registry

BACKGROUND AND PURPOSE

Patients actively smoking at the time of primary hip or knee arthroplasty are at increased risk of direct perioperative complications. We investigated the association between smoking status and risk of revision and mortality within 2 years following hip or knee arthroplasty.

METHODS

We used prospectively collected data from the Dutch Arthroplasty Register. All primary total hip arthroplasties (THAs), total knee arthroplasties (TKAs), and unicondylar knee arthroplasties (UKAs) with > 2 years' follow-up were included (THA: n = 140,336; TKA: n = 117,497; UKA: n = 14,807). We performed multivariable Cox regression analyses to calculate hazard risks for differences between smokers and non-smokers, while adjusting for confounders (aHR).

RESULTS

The smoking group had higher risk of revision (THA: aHR 1.3, 95% confidence interval [CI] 1.1-1.4 and TKA: aHR 1.4, CI 1.3-1.6) and risk of mortality (THA: aHR 1.4, CI 1.3-1.6 and TKA: aHR 1.4, CI 1.2-1.6). Following UKA, smokers had a higher risk of mortality (aHR 1.7, CI 1.0-2.8), but no differences in risk of revision were observed. The smoking group had a higher risk of revision for infection following TKA (aHR 1.3, CI 1.0-1.6), but not following THA (aHR 1.0, CI 0.8-1.2).

CONCLUSION

This study showed that the risk of revision and mortality is higher for smokers than for non-smokers in the first 2 years following THA and TKA. Smoking could contribute to complications following primary hip or knee arthroplasty.

Distal Femoral Osteotomy for the Management of Coronal Deformity Following Total Knee Arthroplasty: A Report of 2 Cases

CASE

We present 2 cases demonstrating the management of coronal malalignment with an existing total knee arthroplasty using opening wedge distal femur osteotomy. The mechanical axis was corrected, and the primary total knee implants were maintained. Patients resumed full activity 3 to 4 months after surgery.

CONCLUSION

In certain cases, opening wedge distal femoral osteotomy is an option to correct coronal malalignment with an existing total knee arthroplasty without revising the implant.

Higher revision rates in patients with preoperative contralateral pes planovalgus deformity following total knee arthroplasty

PURPOSE

The purpose of this study was to compare the incidence of revision in those with pes planovalgus deformity to those without using a large national database. Given the reciprocal changes in lower extremity alignment associated with planovalgus foot deformity, it has been suggested that patients with this deformity has worse outcomes following total knee arthroplasty (TKA).

METHODS

A retrospective cohort analysis of patients undergoing elective TKA was conducted using the PearlDiver database. Patients were stratified into three cohorts: those without pes planovalgus, patients with ipsilateral or bilateral pes planovalgus relative to the TKA, and patients with contralateral pes planovalgus. Patients with prior foot reconstructive surgery were excluded. The cohorts were each matched to those without pes planovalgus. Bivariate analysis was performed comparing 90-day medical complications and 2- and 4-year revisions following TKA. An adjusted number needed to be exposed for one additional person to be harmed (NNEH) was calculated using the adjusted odds ratio (OR) and unexposed event rate.

RESULTS

Following matched analysis, those with contralateral pes planovalgus had similar odds (OR 3.41; 95% CI 0.93-12.54; p = n.s.) for aseptic revision within 2 years but significantly higher odds (OR 3.35; 95% CI 1.08-10.41; p = 0.03) within 4 years when compared to those without a pes planovalgus deformity. Within 4 years, there was no significant difference in the incidence of aseptic revision (p = n.s.) in patients with ipsilateral/bilateral pes planovalgus. No patients in any cohort underwent septic revision within 4 years of TKA.

CONCLUSION

This study found that patients with contralateral pes planovalgus deformity had higher odds of aseptic revision within 4 years following primary TKA in a national database, suggesting that the change in gait kinematics associated with this deformity could possibly be associated with increased revision rates.

LEVEL OF EVIDENCE

Level III.

Does interaction occur between risk factors for revision total knee arthroplasty?

INTRODUCTION

Several risk factors for revision TKA have previously been identified, but interactions between risk factors may occur and affect risk of revision. To our knowledge, such interactions have not been previously studied. As patients often exhibit multiple risk factors for revision, knowledge of these interactions can help improve risk stratification and patient education prior to TKA.

MATERIALS AND METHODS

The State Inpatient Databases (SID), part of the Healthcare Cost and Utilization Project (HCUP), were queried to identify patients who underwent TKA between January 1, 2006 and December 31, 2015. Risk factors for revision TKA were identified, and interactions between indication for TKA and other risk factors were analyzed.

RESULTS

Of 958,944 patients who underwent TKA, 33,550 (3.5%) underwent revision. Age, sex, race, length of stay, Elixhauser readmission score, urban/rural designation, and indication for TKA were significantly associated with revision (p < 0.05). Age was the strongest predictor (p  < 0.0001), with younger patients exhibiting higher revision risk. Risks associated with age were modified by an interaction with indication for TKA (p < 0.0001). There was no significant interaction between sex and indication for TKA (p = 0.535) or race and indication for TKA (p = 0.187).

CONCLUSIONS

Age, sex, race, length of stay, Elixhauser readmission score, urban/rural designation, and indication for TKA are significantly associated with revision TKA. Interaction occurs between age and indication.

Does high activity after total and unicompartmental knee arthroplasty increase the risk for aseptic revision?

INTRODUCTION

It has been suggested that high activity might negatively impact implant survival following total and unicompartmental knee arthroplasty (TKA/UKA) and many surgeons advise their patients to only participate in moderate level sport activities. To date, it remains unclear whether such restraints are necessary to assure longevity of the implants.

MATERIALS AND METHODS

We conducted a retrospective study on 1906 knees (1745 TKA, 161 UKA) in 1636 patients aged 45-75 years who underwent primary arthroplasty for primary osteoarthritis. Lower extremity activity scale (LEAS) at a two year follow-up was assessed to define the activity level. Cases were grouped in low (LEAS ≤ 6), moderate (LEAS 7-13) and high activity (LEAS ≥ 14). Cohorts were compared with Kruskal-Wallis- or Pearson-Chi2-Test. Univariate logistic regression was conducted to test for association between activity level at two years and later revisions. Odds ratio was reported and converted to predicted probability. A Kaplan-Meier curve was plotted to predict implant survival.

RESULTS

The predicted implant survival for UKA was 100.0% at two years and 98.1% at five years. The predicted implant survival for TKA was 99.8% at two years, 98.1% at five years. The difference was not significant (p = 0.410). 2.5% of the UKA underwent revision, one knee in the low and three knees in the moderate activity group, differences between the moderate and high activity group were not significant (p = 0.292). The revision rate in the high activity TKA group was lower than in the low and moderate activity groups (p = 0.008). A higher LEAS two years after surgery was associated with a lower risk for future revision (p = 0.001). A one-point increase in LEAS two years after surgery lowered the odds for undergoing revision surgery by 19%.

CONCLUSIONS

The study suggests that participating in sports activity following both UKA and TKA is safe and not a risk factor for revision surgery at a mid-term follow-up. Patients should not be prevented from an active lifestyle following knee replacement.

Low local curvature index and history of previous surgery are risk factors for revision in focal metallic inlay implants

BACKGROUND

Focal chondral defects are debilitating lesions with poor healing potential. Focal metallic inlay implants were developed as a salvage procedure, whose reoperation causes and risk factors for revision are still debatable. The aim of this study is to analyze the local subchondral curvature matching of focal metallic inlay implants and its effects on survival and clinical results.

METHODS

Patients operated with a knee focal metallic inlay resurfacing implant between 2014 and 2017 were eligible. Surgery was indicated for painful, focal, full-thickness cartilage lesions that had failed alternative treatments. Inclusion criteria were patients treated for a lesion ≤ 5 cm2 in the femoral condyle, aged 40-65 years, with complete surgical records and a knee CT scan. The curvature index (Kindex) was calculated as the ratio of the mean curvature of the implant (K1) to the mean curvature of the subchondral bone (K2).

RESULTS

Sixty-nine patients were included, of which 60.9% were female. Mean age was 54.8 ± 6.0. Seven patients (10.1%) underwent revision surgery. When adjusted for age and sex, lesion size was not significantly correlated to revision in a multivariate regression model, while previous surgery and smaller K index were. A positive history for previous surgery was significantly correlated with worse clinical outcomes in surviving patients.

CONCLUSION

A positive history of previous knee surgery and a low local curvature index are risk factors for revision after focal metallic inlay implant resurfacing. Patients with a history of knee surgery should be counseled on the advantages and disadvantages before undergoing a focal resurfacing procedure.

Risk Factors for Failure of Total Ankle Replacements: A Data Linkage Study Using the National Joint Registry and NHS Digital

BACKGROUND

Despite the increasing numbers of ankle replacements, there remains debate about which patients should undergo an ankle replacement, and there are limited studies analyzing risk factors for failure of an ankle replacement. The primary aim of this study is to analyze the risk factors for failure of total ankle replacements.

METHODS

A data linkage study combining the National Joint Registry (NJR) Data and NHS (National Health Service) Digital data was performed. The primary outcome of failure is defined as the removal or exchange of any components of the implanted device. Kaplan-Meier survival charts were used to illustrate survivorship. Multivariable Cox proportional hazards regression models were fitted to analyze potential risk factors for failures or ankle replacements.

RESULTS

The overall 5-year survival was 90.2% (95% CI 89.2%-91.1%). In multivariable (adjusted) Cox regression models, only age (hazard ratio [HR] 0.96, 95% CI 0.94-0.97), body mass index (BMI; HR 1.03, 95% CI 1.01-1.06), and underlying etiology (HR 0.88, 95% CI 0.80-0.97) were associated with an increased risk of failure.

CONCLUSION

This study demonstrates that younger patients and those with an increased BMI have an increased risk of failure of a primary ankle replacement. We also show that rheumatoid patients have higher survivorship than those with osteoarthritis.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

A complex TKA in a post-traumatic arthritic knee with a significant bone loss: A case report and literature review

INTRODUCTION

Total knee arthroplasty is an effective procedure that aims at restoring function and relieving pain. While most surgeons are familiar with primary TKA, some secondary cases are unique and might create a challenge.

CASE PRESENTATION

A young 30-year-old male with no comorbidities had a gunshot injury to his knee. He developed knee arthritis later, which was treated with modular TKA and a cement-screws technique for substitution for bone loss.

DISCUSSION

Complex cases of TKA demand innovative solutions, many options exist now for dealing with various challenges, but they are expensive and not always available, so other choices must be utilized to afford the best possible outcome.

CONCLUSION

Post-traumatic TKA could be technically challenging, and screws buttressing the cement could effectively handle bone defects when other options are unavailable.

Hospital variation in revision rates after primary knee arthroplasty was not explained by patient selection: baseline data from 1452 patients in the Danish prospective multicenter cohort study, SPARK

PURPOSE

Revision rates following primary knee arthroplasty vary by country, region and hospital. The SPARK study was initiated to compare primary surgery across three Danish regions with consistently different revision rates. The present study investigated whether the variations were associated with differences in the primary patient selection.

METHODS

A prospective observational cohort study included patients scheduled Sep 2016 Dec 2017 for primary knee arthroplasty (total, medial/lateral unicompartmental or patellofemoral) at three high-volume hospitals, representing regions with 2-year cumulative revision rates of 1, 2 and 5%, respectively. Hospitals were compared with respects to patient demographics, preoperative patient-reported outcome measures, motivations for surgery, implant selection, radiological osteoarthritis and the regional incidence of primary surgery. Statistical tests (parametric and non-parametric) comprised all three hospitals.

RESULTS

Baseline data was provided by 1452 patients (89% of included patients, 56% of available patients). Patients in Copenhagen (Herlev-Gentofte Hospital, high-revision) were older (68.6 ± 9 years) than those in low-revision hospitals (Aarhus 66.6 ± 10 y. and Aalborg (Farsø) 67.3 ± 9 y., p = 0.002). In Aalborg, patients who had higher Body Mass Index (mean 30.2 kg/m² versus 28.2 (Aarhus) and 28.7 kg/m² (Copenhagen), p < 0.001), were more likely to be male (56% versus 45 and 43%, respectively, p = 0.002), and exhibited fewer anxiety and depression symptoms (EQ-5D-5L) (24% versus 34 and 38%, p = 0.01). The preoperative Oxford Knee Score (23.3 ± 7), UCLA Activity Scale (4.7 ± 2), range of motion (Copenhagen Knee ROM Scale) and patient motivations were comparable across hospitals but varied with implant type. Radiological classification ≥ 2 was observed in 94% (Kellgren-Lawrence) and 67% (Ahlbäck) and was more frequent in Aarhus (low-revision) (p ≤ 0.02), where unicompartmental implants were utilized most (49% versus 14 (Aalborg) and 23% (Copenhagen), p < 0.001). In the Capital Region (Copenhagen), the incidence of surgery was 15-28% higher (p < 0.001).

CONCLUSION

Patient-reported outcome measures prior to primary knee arthroplasty were comparable across hospitals with differing revision rates. While radiographic classifications and surgical incidence indicated higher thresholds for primary surgery in one low-revision hospital, most variations in patient and implant selection were contrary to well-known revision risk factors, suggesting that patient selection differences alone were unlikely to be responsible for the observed variation in revision rates across Danish hospitals.

LEVEL OF EVIDENCE

II, Prospective cohort study.

Comparison with Navigation of a Novel Three-Step Technique for Improving Accuracy of the Distal Femoral Resection during Conventional TKA: A Case-Control Study

Correct placement of the femoral component in the coronal plane during primary total knee arthroplasty (TKA) is related to long-term survival. The aim of this radiographic study was to determine the accuracy of a novel three-step technique for improving the accuracy of the distal femoral cut during conventional technique and compare it with computer navigation during TKA. A total of 458 TKAs were retrospectively analyzed (178 conventional TKAs with the novel technique and 280 navigated TKAs) for postoperative femoral component coronal alignment and compared between the two groups. Mean femoral component coronal alignment was not significantly different (p = 0.314) between the two groups. There was no significant difference in the mean femoral component coronal alignment between varus and valgus knees. The number of outliers (90 ± 3 degrees) for femoral component coronal alignment was not significantly different between the two groups when assessed separately for varus and valgus deformities. The mean value of femoral component alignment using the conventional technique in knees with varus deformity <10 degrees was 88.8 degrees, in knees with varus deformity 10 to 20 degrees was 89.4 degrees, and in those with varus deformity >20 degrees was 90.2 degrees. Femoral component alignment in knees with varus <10 degrees was significantly different from those >20 degrees (p = 0.006); there was no significant difference between knees with varus <10 degrees and those with 10 to 20 degrees varus (p = 0.251), nor between 10 and 20 degrees varus knees and those with varus >20 degrees (p = 0.116). Using the novel three-step technique during conventional TKA to perform the distal femoral cut can help achieve femoral component coronal alignment comparable to the navigation technique.

Impact of Chronic Obstructive Pulmonary Disease on Outcomes After Total Joint Arthroplasty: A Meta-analysis and Systematic Review

Background

Comorbid chronic obstructive pulmonary disease (COPD) is increasingly common and may have an adverse impact on outcomes in patients undergoing total joint arthroplasty (TJA) of lower extremity. The purpose of this meta-analysis is to compare the postoperative complications between COPD and non-COPD patients undergoing primary TJA including total hip and knee arthroplasty.

Methods

PubMed, EMBASE, and Cochrane Library were systematically searched for relevant studies published before December 2021. Postoperative outcomes were compared between patients with COPD versus those without COPD as controls. The outcomes were mortality, re-admission, pulmonary, cardiac, renal, thromboembolic complications, surgical site infection (SSI), periprosthetic joint infection (PJI), and sepsis.

Results

A total of 1,002,779 patients from nine studies were finally included in this meta-analysis. Patients with COPD had an increased risk of mortality (OR [odds ratio] = 1.69, 95% confidence interval [CI] 1.42-2.02), re-admission (OR = 1.54, 95% CI 1.38-1.71), pulmonary complications (OR = 2.73, 95% CI 2.26-3.30), cardiac complications (OR = 1.40, 95% CI 1.15-1.69), thromboembolic complications (OR = 1.21, 95% CI 1.15-1.28), renal complications (OR = 1.50, 95% CI 1.14-1.26), SSI (OR = 1.23, 95% CI 1.18-1.30), PJI (OR = 1.26, 95% CI 1.15-1.38), and sepsis (OR = 1.36, 95% CI 1.22-1.52).

Conclusion

Patients with comorbid COPD showed an increased risk of mortality and postoperative complications following TJA compared with patients without COPD. Therefore, orthopedic surgeons can use the study to adequately educate these potential complications when obtaining informed consent. Furthermore, preoperative evaluation and medical optimization are crucial to minimizing postoperative complications from arising in this difficult-to-treat population.

Level of evidence

Level III.

Registration

None.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-022-00794-2.

A high physical activity level after total knee arthroplasty does not increase the risk of revision surgery during the first twelve years: A systematic review with meta-analysis and GRADE

BACKGROUND

High physical activity (HPA) levels after total knee arthroplasty (TKA) might be related to increased wear and subsequent aseptic loosening, negatively affecting TKA survival. This systematic review studied the association between activity levels and risk of revision surgery at medium (3-10 years) and long term (>10 years) follow up in patients with TKA.

METHODS

Databases (PubMed, Embase) were searched up to 12 October 2021. Studies comparing low physical activity (LPA) and HPA levels in TKA patients and related risk of revision surgery were eligible for inclusion. After data extraction and evaluation of methodological quality, a meta-analysis was performed. Quality of evidence was assessed using the GRADE framework. PROSPERO registration: CRD42020194284.

RESULTS

Five cohort studies and one case-control study met the inclusion criteria, involving 4811 TKA procedures in 4263 patients (mean follow up 4-12 years). Five studies were of moderate methodological quality and one of low quality. Meta-analysis demonstrated no association between HPA level and an increased risk of all-cause revision surgery (risk ratio (RR) 0.62, 95 % confidence interval (CI) 0.24-1.63, level of certainty: very low) or revision surgery due to aseptic loosening (RR 1.33, 95 % CI 0.34-5.24, level of certainty: moderate). Only one study reported on survivorship, with an improved survivorship for the HPA group (odds ratio of 2.4, 95 % CI 1.2-4.7, level of certainty: low).

CONCLUSION

During the first 12 postoperative years after TKA, there seems to be no increased risk for revision surgery for patients with a HPA level compared with patients with an LPA level.

Long-Term Clinical Performance of an Uncemented, Mobile Bearing, Anterior Stabilized Knee System and the Impact of Previous Knee Surgery

BACKGROUND

The aim of this study is to report long-term survival and patient-reported outcome measures (PROMs) of the uncemented low contact stress total knee system and explore the potential association between prior knee surgery and outcomes.

METHODS

A total of 1,289 procedures in 1,068 patients performed between 2000 and 2010 (mean follow-up 11.1 years) were retrospectively identified. All patients received an uncemented, mobile bearing, anterior stabilized (cruciate sacrificing) knee implant with a porous coating on the bone-prosthesis surface. Implant survival was calculated using competing risk analyses at 5, 10, and 15 years. PROMs include the Oxford Knee Score, Knee Society Score (domain function), EuroQol 5D-3L, and Numeric Rating Scale for pain during rest and activity, and for overall satisfaction. The association between previous surgery (no surgery versus meniscectomy versus arthroscopy versus corrective osteotomies) and implant survival was assessed with multivariable Cox proportional hazards analysis; the association with PROMs was assessed with multivariable linear regression analyses.

RESULTS

Survival after 5, 10, and 15 years was 97.0% (95% CI 96.0-98.0), 96.3% (95% CI 95.3-97.3), and 96.0% (95% CI 94.8-97.2), respectively. The most common reason for revision was aseptic loosening of the tibial tray (23/49 revisions, 47%). All PROMs were comparable with the reference values of the Dutch Arthroplasty Register. History of knee surgery prior to TKA was not associated with survival or PROMs.

CONCLUSION

The low contact stress uncemented mobile bearing knee implant provides excellent survival and patient satisfaction in our cohort. Previous surgery does not seem to compromise results in our population.

Head-to-Head Comparison of Kinematic Alignment Versus Mechanical Alignment for Total Knee Arthroplasty

BACKGROUND

Seeing as there are many alignment strategies for total knee arthroplasty (TKA), we need to determine differences between them in a rigorous scientific way. Therefore, we sought to compare perioperative and postoperative functional outcomes in patients undergoing TKA for varus osteoarthritis with a mechanical alignment target vs a kinematic alignment target, both executed with the same implant and same technological guidance.

METHODS

One hundred consecutive patients who underwent TKA using a mechanical alignment technique were 1:1 matched to 100 patients who underwent TKA using a kinematic alignment (KA) technique, using the same implant and robotic technology. Patient-reported outcomes were measured postoperatively at 1 and 2 years. Power analysis revealed 94 patients to detect a significant difference.

RESULTS

Mean Visual Analog Scale scores were higher in the mechanical alignment group during the first 6 weeks (P = .04), but statistically similar at 1 year. Six-week Veterans RAND 12 Item Health Survey mental and physical components were statistically similar (P = .1). Patients did not differ in 6-week or 1-year knee range of motion (P > .43). Knee Injury and Osteoarthritis Outcome Score Joint Replacement was significantly better in the KA group at 6 weeks, 1 year, and 2 years (P = .09). Forgotten Joint Score at 1 and 2 years postoperatively were significantly higher in the KA group (P < .001).

CONCLUSION

Patients undergoing TKA with KA experienced less pain in 6 weeks after surgery, and higher Forgotten Joint Scores at 1 and 2 years postoperatively. Alternative TKA alignment and balancing strategies should be considered to increase patient satisfaction.

Sensor-guided gap balance versus manual gap balance in primary total knee arthroplasty: a meta-analysis

Background

Despite Vast improvements in technology and surgical technique in total knee arthroplasty (TKA), approximately 15–25% TKAs, have suboptimal subjective clinical outcomes. Our study sought to evaluate if sensor-guided balancing improves postoperative clinical outcomes compared to a conventional gap balancing technique.

Methods

We searched Web of Science, Embase, PubMed, Cochrane Controlled Trials Register, Cochrane Library, Highwire, CBM, CNKI, VIP, and Wanfang database in March 2022 to identify studies involving sensor-guided balancing versus conventional gap balancing technique in TKA. Finally, we identified 2147 knees assessed in nine studies.

Results

Compared with manual gap balancing, Sensor-guided gap balancing resulted in less rate of Manipulation under anesthesia (MUA) (P = 0.02), however more rate of intraoperative additional procedures (P = 0.0003). There were no significant differences in terms of KSS (P = 0.21), KSS Function score (P = 0.36), OKS (P = 0.61), KOOS (P = 0.78), operative time (P = 0.17), Mechanical axis (P = 0.69) and rate of reoperation between two groups.

Conclusion

Compared with conventional manual gap balancing techniques, sensors have more balancing procedures being performed. However, it did result in a reduction in the rate of MUA. More extensive, high-quality RCTs are required to verify our findings further.

Complications, readmission rates, and in-hospital lengths-of-stay in octogenarian vs. non-octogenarians following total knee arthroplasty: An analysis of over 1.7 million patients

INTRODUCTION

Studies investigating complications between octogenarians and non-octogenarians undergoing primary total knee arthroplasty (TKA) are limited. Therefore, we investigated whether octogenarians are at greater odds of: (1) in-hospital lengths of stay (LOS) (2) readmission rates, (3) medical complications, and (4) hardware complications compared to non-octogenarians following TKA.

METHODS

A retrospective query of the PearlDiver database isolated 1,775,460 patients who underwent primary TKA from 2005 to 2014. Patients aged 80 and above represented the study cohort (n = 295,908) and patients 65 to 79 represented the control cohort (n = 1,479,552). Study group patients were matched to controls in a 1:5 ratio according to gender and medical comorbidities. Pearson's Chi Square and logistic regression were used to analyze the primary outcomes of the study which included 90-day medical complications, 90-day readmission rates, 2-year implant-related complications, and in-hospital LOS. A p-value less than 0.001 was statistically significant.

RESULTS

Octogenarians were found to have significantly higher incidence and odds of 90-day readmission rates (10.59 vs. 9.35%; OR: 1.15, p < 0.0001) and significantly longer in-hospital LOS (3.69 days ± 1.95 vs. 3.23 days ± 1.83, p < 0.0001) compared to controls. Octogenarians also had equal incidence and odds of developing any medical complication (1.26 vs. 1.26%; OR: 0.99, p = 0.99) and lower incidence and odds (1.67 vs. 1.93%; OR: 0.86, p < 0.001) of implant-related complications compared to controls.

CONCLUSION

Octogenarians undergoing primary TKA have similar odds of medical related complications and lower odds of implant-related complications compared to non-octogenarian patients, whereas readmission rates and in-hospital LOS are greater.

Unicompartmental Knee Arthroplasty: Survivorship and Risk Factors for Revision: A Population-Based Cohort Study with Minimum 10-Year Follow-up

BACKGROUND

Operative management for end-stage knee osteoarthritis (OA) primarily consists of arthroplasty. Total knee arthroplasty (TKA) is the so-called gold standard for multicompartmental OA. In selected patients, specifically those with unicompartmental OA and no definite contraindications, realignment osteotomies and unicompartmental knee arthroplasty (UKA) are viable options. UKA offers several advantages over TKA, including preservation of both cruciate ligaments, faster recovery, and less osseous resection. The purpose of this study was to determine the survivorship of UKAs and risk factors for all-cause revision surgery in patients with a minimum follow-up of 10 years in a large population-based database.

METHODS

We performed a population-based cohort study using linked administrative databases in Ontario, Canada. We identified all UKAs performed from January 2002 through December 2006. All patients had a minimum 10-year follow-up. Demographic data and outcomes were summarized using descriptive statistics. We used a Cox proportional hazards model with the Fine and Gray method accounting for competing risks such as death to analyze the effect of surgical and patient factors on the risk of revision of UKA.

RESULTS

A total of 4,385 patients were identified as having undergone primary UKA from 2002 through 2006 in Ontario. Of these patients, 779 underwent revision surgery, for a cumulative risk for all-cause revision of 16.5% at 10 years (95% confidence interval [CI]: 15.4% to 17.7%). Mechanical loosening was the reason for 83.4% of all revisions. Male sex, diabetes, an age younger than 50 years, and cementless implants were significant risk factors for revision surgery. Residence in a rural or urban setting, income quintile, discharge destination, and type of OA were not associated with the risk of revision. Survivorship at 1, 5, 10, and 15 years was 97.2%, 90.5%, 83.5%, and 81.9%, respectively.

CONCLUSIONS

This study demonstrated a >80% long-term survivorship for UKA based on a large administrative database sample and identified important risk factors for failure including male sex, younger age, diabetes, and cementless fixation. This study found rates of survivorship similar to those previously reported in the literature, while identifying key risk factors for failure. Patient selection has always been identified as a key factor in ensuring successful UKA, and the risk factors identified in this study may help guide decision-making for surgeons and patients dealing with unicompartmental knee OA.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Isolated tibial insert exchange in revision total knee arthroplasty : reliable and durable for wear; less so for instability, insert fracture/dissociation, or stiffness

AIMS

This study aimed to determine outcomes of isolated tibial insert exchange (ITIE) during revision total knee arthroplasty (TKA).

METHODS

From 1985 to 2016, 270 ITIEs were performed at one institution for instability (55%, n = 148), polyethylene wear (39%, n = 105), insert fracture/dissociation (5%, n = 14), or stiffness (1%, n = 3). Patients with component loosening, implant malposition, infection, and extensor mechanism problems were excluded.

RESULTS

Survivorship free of any re-revision was 68% at ten years. For the indication of insert wear, survivorship free of any re-revision at ten years was 74%. Re-revisions were more frequent for index diagnoses other than wear (hazard ratio (HR) 1.9; p = 0.013), with ten-year survivorships of 69% for instability and 37% for insert fracture/dissociation. Following ITIE for wear, the most common reason for re-revision was aseptic loosening (33%, n = 7). For other indications, the most common reason for re-revision was recurrence of the original diagnosis. Mean Knee Society Scores improved from 54 (0 to 94) preoperatively to 77 (38 to 94) at ten years.

CONCLUSION

After ITIE, the risk and reasons for re-revision correlated with preoperative indications. The best results were for polyethylene wear. For other diagnoses, the re-revision rate was higher and the failure mode was most commonly recurrence of the original indication for the revision TKA. Cite this article: Bone Joint J 2021;103-B(6):1103-1110.

The Association of International Normalized Ratio with Postoperative Complications in Revision Total Knee Arthroplasty

The purpose of this study was to examine the relationship between elevated preoperative international normalized ratio (INR) and (1) mortality, (2) postoperative bleeding, and (3) other postoperative complications in a national cohort of patients who underwent revision total knee arthroplasty (rTKA). The American College of Surgeons National Surgical Quality Improvement Program was queried for rTKA procedures conducted between 2006 and 2017. Cohorts were based on INR ranges: <1, 1 < INR ≤ 1.25, 1.25 < INR ≤ 1.5, and >1.5. Univariate/multivariate statistics were calculated to analyze associations between INR value and designated covariates. These statistics were additionally applied to optimal cutoff values of INR calculated using a receiver operating characteristics curve. The final cohort consisted of 1,676 patients. Progressively higher INR values were associated with an increased risk of mortality within 30 days (p < 0.006), bleeding requiring transfusion (p < 0.001), sepsis (p < 0.001), return to the operating room (Odds Ratio [OR], p = 0.011), reintubation (p < 0.001), pneumonia (p < 0.001), failure to wean from mechanical ventilation ≤48 hours (p < 0.001), acute renal failure (p = 0.001), and hospital length of stay (LOS). Statistically significant associations were similarly seen when calculated optimal INR values were used. Optimal INR turn point was found to be associated with a significant increased risk of long LOS (optimal INR = 1.03, OR: 1.7, 95% confidence interval [CI]: 1.33-2.18; p < 0.001) and a significant decreased risk of bleeding requiring transfusion (INR = 1.005, OR: 0.732, 95% CI: 0.681-0.786; p < 0.001). High preoperative INR values were independently and significantly associated with an increased risk of multiple postoperative complications. Current guidelines for INR <1.5 should be reassessed for patients undergoing rTKA.

Anesthetic Management of A Patient with Charcot-Marie-Tooth Disease for 2-stage Revision of Total Knee Replacement

Charcot-Marie-Tooth disease is characterised by hereditary motor and sensory neuropathy. Its anaesthetic management is challenging owing to the unpredictable response observed in patients, especially to non-depolarising neuromuscular blocking drugs, and the risk of malignant hyperthermia and cardiorespiratory complications. A 66-year-old woman underwent anaesthesia for 2 different surgical procedures, a 2-stage revision of total knee replacement over a 4-month period. She presented with severe anatomic disorders, accompanied by severe motor and sensory impairment. An anaesthetic plan without neuromuscular blocking drugs or volatile anaesthetics, using a clean ventilator, with dantrolene available, was successfully used both times. There were no complications during the administration of general anaesthesia or postoperatively at the post-anaesthesia care unit, and the patient did not complain of pain at any time. General anaesthesia with a careful selection of anaesthetic drugs proved to be a safe option for the management of a patient with Charcot-Marie-Tooth disease.

Global Research Trends in Revision Total Knee Arthroplasty: A Bibliometric and Visualized Study

BACKGROUND

Revision total knee arthroplasty (TKA) is a longstanding area of research interest in orthopedics due to its increasing global demand and associated technical challenges. The present study aims to analyze and present the current state of research and trends in this active field.

METHODS

Articles on revision TKA published from inception to 2018 were retrieved from Web of Science. Bibliometric analysis was conducted using the metadata of the included articles. Visualized analysis was conducted using VOSviewer software to reveal global trends in revision TKA research, through analyses of bibliographic coupling, co-authorship, co-citation and co-occurrence.

RESULTS

A total of 6027 articles were included. The number of publications and relative research interest in the field of revision TKA displayed strong upward growth over the time period examined. The USA had the highest number of citations for publications in this field, as well as the highest H-index. Studies in the field could be categorized into five clusters: prosthesis design, periprosthetic fracture, periprosthetic joint infection, risk factors for revision TKA, and survivorship of implants. Studies focused on infection and risk factors for revision TKA are likely to become the most popular research topics in the field.

CONCLUSION

Global trends over the past few years suggest that the field of revision TKA research will continue to grow and lead to increasing rates of publication output over the coming years. Future developments in the field will likely include more preventative and etiological studies relating to revision TKA.

Diagnosis and Treatment of Hip and Knee Osteoarthritis: A Review

Importance

Osteoarthritis (OA) is the most common joint disease, affecting an estimated more than 240 million people worldwide, including an estimated more than 32 million in the US. Osteoarthritis is the most frequent reason for activity limitation in adults. This Review focuses on hip and knee OA.

Observations

Osteoarthritis can involve almost any joint but typically affects the hands, knees, hips, and feet. It is characterized by pathologic changes in cartilage, bone, synovium, ligament, muscle, and periarticular fat, leading to joint dysfunction, pain, stiffness, functional limitation, and loss of valued activities, such as walking for exercise and dancing. Risk factors include age (33% of individuals older than 75 years have symptomatic and radiographic knee OA), female sex, obesity, genetics, and major joint injury. Persons with OA have more comorbidities and are more sedentary than those without OA. The reduced physical activity leads to a 20% higher age-adjusted mortality. Several physical examination findings are useful diagnostically, including bony enlargement in knee OA and pain elicited with internal hip rotation in hip OA. Radiographic indicators include marginal osteophytes and joint space narrowing. The cornerstones of OA management include exercises, weight loss if appropriate, and education-complemented by topical or oral nonsteroidal anti-inflammatory drugs (NSAIDs) in those without contraindications. Intra-articular steroid injections provide short-term pain relief and duloxetine has demonstrated efficacy. Opiates should be avoided. Clinical trials have shown promising results for compounds that arrest structural progression (eg, cathepsin K inhibitors, Wnt inhibitors, anabolic growth factors) or reduce OA pain (eg, nerve growth factor inhibitors). Persons with advanced symptoms and structural damage are candidates for total joint replacement. Racial and ethnic disparities persist in the use and outcomes of joint replacement.

Conclusions and Relevance

Hip and knee OA are highly prevalent and disabling. Education, exercise and weight loss are cornerstones of management, complemented by NSAIDs (for patients who are candidates), corticosteroid injections, and several adjunctive medications. For persons with advanced symptoms and structural damage, total joint replacement effectively relieves pain.

Monitoring Hospital Performance with Statistical Process Control After Total Hip and Knee Arthroplasty: A Study to Determine How Much Earlier Worsening Performance Can Be Detected

BACKGROUND

Given the low early revision rate after total hip arthroplasty (THA) and total knee arthroplasty (TKA), hospital performance is typically compared using 3 years of data. The purpose of this study was to assess how much earlier worsening hospital performance in 1-year revision rates after THA and TKA can be detected.

METHODS

All 86,468 THA and 73,077 TKA procedures performed from 2014 to 2016 and recorded in the Dutch Arthroplasty Register were included. Negative outlier hospitals were identified by significantly higher O/E (observed divided by expected) 1-year revision rates in a funnel plot. Monthly Shewhart p-charts (with 2 and 3-sigma control limits) and cumulative sum (CUSUM) charts (with 3.5 and 5 control limits) were constructed to detect a doubling of revisions (odds ratio of 2), generating a signal when the control limit was reached. The median number of months until generation of a first signal for negative outliers and the number of false signals for non-negative outliers were calculated. Sensitivity, specificity, and accuracy were calculated for all charts and control limit settings using outlier status in the funnel plot as the gold standard.

RESULTS

The funnel plot showed that 13 of 97 hospitals had significantly higher O/E 1-year revision rates and were negative outliers for THA and 7 of 98 hospitals had significantly higher O/E 1-year revision rates and were negative outliers for TKA. The Shewhart p-chart with the 3-sigma control limit generated 68 signals (34 false-positive) for THA and 85 signals (63 false-positive) for TKA. The sensitivity for THA and TKA was 92% and 100%, respectively; the specificity was 69% and 51%, respectively; and the accuracy was 72% and 54%, respectively. The CUSUM chart with a 5 control limit generated 18 signals (1 false-positive) for THA and 7 (1 false-positive) for TKA. The sensitivity was 85% and 71% for THA and TKA, respectively; the specificity was 99% for both; and the accuracy was 97% for both. The Shewhart p-chart with a 3-sigma control limit generated the first signal for negative outliers after a median of 10 months (interquartile range [IQR] = 2 to 18) for THA and 13 months (IQR = 5 to 18) for TKA. The CUSUM chart with a 5 control limit generated the first signal after a median of 18 months (IQR = 7 to 22) for THA and 21 months (IQR = 9 to 25) for TKA.

CONCLUSIONS

Monthly monitoring using CUSUM charts with a 5 control limit enables earlier detection of worsening 1-year revision rates with accuracy so that initiatives to improve care can start earlier.

Impact of suspending minimum volume requirements for knee arthroplasty on hospitals in Germany: an uncontrolled before-after study

Background

In 2004, the Federal Joint Committee, supreme decision-making body in German healthcare, introduced minimum volume requirements (MVRQs) as a quality instrument. Since then, MVRQs were implemented for seven hospital procedures. This study evaluates the effect of a system-wide intermission of MVRQ for total knee arthroplasty (TKA), demanding 50 annual cases per hospital.

Methods

An uncontrolled before–after study based on federal-level data including the number of hospitals performing TKA, and TKA cases from the external hospital quality assurance programme in Germany (2004–2017). Bi- and multivariate analyses based on hospital-level secondary data of TKA cases and TKA quality indicators extracted from hospital quality reports in Germany (2006–2014).

Results

The number of TKAs performed in Germany decreased by 11% after suspending the TKA-MVRQ in 2011, and rose by 13% after its reintroduction in 2015. The number of hospitals with less than 50 cases rose from 10 to 25% and their case share from 2 to 5.5% during suspension. Change in hospital volume after the suspension of TKA-MVRQ was not associated with hospital size, ownership, or region. All four evaluable quality indicators increased significantly in the year after their first public reporting. Compared to hospitals meeting the TKA-MVRQ, three indicators show slight but statistically significant better quality in hospitals below the TKA-MVRQ.

Conclusions

In Germany, TKA-MVRQs seem to induce in-hospital caseload adjustments rather than foster regional inter-hospital case transfers as intended.

Risk factors for aseptic loosening in complex revision total knee arthroplasty using rotating hinge implants

PURPOSE

This study aimed to determine the risk factors of aseptic loosening (AL) in complex revision total knee arthroplasty (TKA) cases using rotating hinge knee prosthesis.

METHODS

Patients who had undergone re-revision rotating hinge prosthesis surgery between January 2012 and December 2017 were included. Parameters related to AL were retrospectively reviewed. For this purpose, 31 aseptic loosening patients and 30 control patients were included in the study. Various risk factors were evaluated. Risk factors for AL after re-revision were determined using univariate and multiple logistic regression analyses.

RESULTS

Thirty-one AL patients and 30 control patients were included. In the AL group, tibial tantalum cone and impaction grafting were performed significantly less frequently than the control group (p = 0.002 and p < 0.001). Logistic regression analysis revealed that smoking, right-sided TKA, and large femoral canal anteroposterior diameter were factors that increased the risk of AL after re-revision, while tibial tantalum cone decreased the risk of loosening. Smokers had an 11.847-fold higher risk for AL; right-sided TKA led to a 4.594-fold higher risk for AL. However, the presence of a tibial tantalum cone was associated with an 8.403-fold lower risk for AL.

CONCLUSIONS

We conclude that smoking, right-sided prosthesis, and large femoral canal diameter increased the risk of AL, while tantalum cone and impaction grafting reduced this risk in patients who underwent re-revision surgery with rotating hinge prosthesis after TKA.

Melt electrowriting onto anatomically relevant biodegradable substrates: Resurfacing a diarthrodial joint

Three-dimensional printed hydrogel constructs with well-organized melt electrowritten (MEW) fibrereinforcing scaffolds have been demonstrated as a promising regenerative approach to treat small cartilage defects. Here, we investige how to translate the fabrication of small fibre-reinforced structures on flat surfaces to anatomically relevant structures. In particular, the accurate deposition of MEW-fibres onto curved surfaces of conductive and non-conductive regenerative biomaterials is studied. This study reveals that clinically relevant materials with low conductivities are compatible with resurfacing with organized MEW fibres. Importantly, accurate patterning on non-flat surfaces was successfully shown, provided that a constant electrical field strength and an electrical force normal to the substrate material is maintained. Furthermore, the application of resurfacing the geometry of the medial human femoral condyle is confirmed by the fabrication of a personalised osteochondral implant. The implant composed of an articular cartilage-resident chondroprogenitor cells (ACPCs)-laden hydrogel reinforced with a well-organized MEW scaffold retained its personalised shape, improved its compressive properties and supported neocartilage formation after 28 days in vitro culture. Overall, this study establishes the groundwork for translatingMEWfrom planar and non-resorbable material substrates to anatomically relevant geometries and regenerative materials that the regenerative medicine field aims to create.

The Cost-Effectiveness of Platelet-Rich Plasma Injections for Knee Osteoarthritis: A Markov Decision Analysis

BACKGROUND

Use of platelet-rich-plasma (PRP) injections for treating knee osteoarthritis has increased over the past decade. We used cost-effectiveness analysis to evaluate the value of PRP in delaying the need for total knee arthroplasty (TKA).

METHODS

We developed a Markov model to analyze the baseline case: a 55-year-old patient with Kellgren-Lawrence grade-II or III knee osteoarthritis undergoing a series of 3 PRP injections with a 1-year delay to TKA versus a TKA from the outset. Both health-care payer and societal perspectives were included. Transition probabilities were derived from systematic review of 72 studies, quality-of-life (QOL) values from the Tufts University Cost-Effectiveness Analysis Registry, and individual costs from Medicare reimbursement schedules. Primary outcome measures were total costs and quality-adjusted life years (QALYs), organized into incremental cost-effectiveness ratios (ICERs) and evaluated against willingness-to-pay thresholds of $50,000 and $100,000. One and 2-way sensitivity analyses were performed as well as a probabilistic analysis varying PRP-injection cost, TKA delay intervals, and TKA outcomes over 10,000 different simulations.

RESULTS

From a health-care payer perspective, PRP resulted in 14.55 QALYs compared with 14.63 for TKA from the outset, with total health-care costs of $26,619 and $26,235, respectively. TKA from the outset produced a higher number of QALYs at a lower cost, so it dominated. From a societal perspective, PRP cost $49,090 versus $49,424 for TKA from the outset. The ICER for TKA from the outset was $4,175 per QALY, below the $50,000 willingness-to-pay threshold. Assuming the $728 published cost of a PRP injection, no delay time that was <10 years produced a cost-effective course. When the QOL value was increased from the published value of 0.788 to >0.89, PRP therapy was cost-effective with even a 1-year delay to TKA.

CONCLUSIONS

When considering direct and unpaid indirect costs, PRP injections are not cost-effective. The primary factor preventing PRP from being cost-effective is not the price per injection but rather a lack of established clinical efficacy in relieving pain and improving function and in delaying TKA. PRP may have value for higher-risk patients with high perioperative complication rates, higher TKA revision rates, or poorer postoperative outcomes.

LEVEL OF EVIDENCE

Economic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Tibial alignment technique and its influence on clinical and functional outcomes following total knee arthroplasty

BACKGROUND

Restoration of neutral mechanical axis is thought to influence implant survival and function in Total Knee Arthroplasty (TKA). There is no consensus whether Intramedullary (IM) or Extramedullary (EM) tibial alignment technique is superior to achieve this outcome. Study aims to evaluate functional and radiological outcome of TKA using the EM and IM technique.

MATERIALS AND METHODS

A retrospective study of 400 primary TKA (314 patients) was performed. 200 knees were studied in each IM and EM group, which were matched. Functional assessment was performed using Oxford Knee Score (OKS) and Tibial component alignment measured in coronal and sagittal radiographs.

RESULTS

The average coronal and sagittal alignment of the tibial component in IM group was 89.16° and 88°, whereas in EM group, these were 88.1° and 88.5° respectively. The adjusted mean difference change in Pre and Post-operative OKS in IM group compared to EM group was 0.5 (p = 0.52). There was no statistically significant difference in the complications between the two groups. Subgroup analysis of patients with BMI >35 showed predictable coronal tibial alignment with IM technique with fewer outliers.

CONCLUSION

Intramedullary tibial alignment is associated with fewer outliers compared to the extramedullary technique particularly in patients with a BMI over 35.

A synthetic bone insert may protect the lateral cortex and fixation plate following a high tibial osteotomy by reducing the tensile strains

PURPOSE

To determine the effectiveness of a synthetic bone insert on improving medial opening wedge high tibial osteotomy integrity in response to post-surgical cyclical loading.

MATERIALS AND METHODS

A medial opening wedge high tibial osteotomy, secured with a compression fixation plate, was performed on 12 cadaveric knee specimens that were randomised to either: (1) a synthetic insert condition (n = 6), in which a 9 mm bio-absorbable wedge was inserted into the gap space; or (2) a plate-only condition (n = 6). Uniaxial strain gauges, placed on the lateral cortex and fixation plate, measured the strain response as the specimens were subjected to a staircase cyclical loading protocol; a sinusoidal waveform between 100 and 800 N was applied and increased by increments of 200 N every 5000 cycles until failure. Peak strains at failure were compared between conditions using a one-tailed independent samples t test.

RESULTS

The strains from the fixation plate were significantly different between the insert and plate only conditions (p = 0.02), transitioning from a compressive strain with the wedge (mean [SD] = - 8.6 [- 3.6] µε) to a tensile strain without the wedge (mean [SD] = 12.9 [23] µε). The strains measured at the lateral cortex were also significantly affected by the inclusion of a synthetic bone insert (p = 0.016), increasing from - 55.6 (- 54.3) µε when the insert was utilised to 23.7 (55.7) µε when only the plate was used.

CONCLUSIONS

The addition of a synthetic insert limited the tensile strains at the plate and lateral cortex, suggesting that this may protect these regions from fracture during prolonged loading.

Reduced survival of total knee arthroplasty after previous unicompartmental knee arthroplasty compared with previous high tibial osteotomy: a propensity-score weighted mid-term cohort study based on 2,133 observations from the Danish Knee Arthroplasty Registry

Background and purpose - Both medial unicompartmental knee arthroplasties (UKA) and high tibial osteotomies (HTO) are reliable treatments for isolated medial knee osteoarthritis. However, both may with time need conversion to a total knee arthroplasty (TKA). We conducted the largest nationwide registry comparison of the survival of TKA following UKA with TKA following HTO.Patients and methods - From the Danish Knee Arthroplasty Registry, aseptic conversions to TKA from UKA and TKA converted from HTO within the period of 1997-2018 were retrieved. The Kaplan-Meier method and the Cox proportional hazards regression were used to estimate the survival and hazard ratio (HR) for revision, considering confounding by indication utilizing propensity-score based inverse probability of treatment weighting (PS-IPTW).Results - PS-IPTW yielded a well-balanced pseudo-cohort (standard mean difference (SMD) < 0.1 for all covariates, except implant supplementation) of 963.8 TKAs following UKA and 1139.1 TKAs following HTO. The survival of TKA following UKA was significantly less than that of TKA following HTO with a 5-year estimated survival of 0.88 (95% confidence interval (CI) 0.85-0.90) and 0.94 (CI 0.93-0.96), respectively. The differences in survival corresponded to an implant-supplementation adjusted HR of 2.7 (CI 2.4-3.1) for TKA following UKA compared with TKA following HTO.Interpretation - Previous UKA more than doubled the revision risk of a subsequent TKA compared with previous HTO. This potential risk should be considered in the shared treatment decision of patients who are candidates for both UKA and HTO.

Pathomechanisms of Posttraumatic Osteoarthritis: Chondrocyte Behavior and Fate in a Precarious Environment

Traumatic injuries of the knee joint result in a wide variety of pathomechanisms, which contribute to the development of so-called posttraumatic osteoarthritis (PTOA). These pathogenetic processes include oxidative stress, excessive expression of catabolic enzymes, release of damage-associated molecular patterns (DAMPs), and synovial inflammation. The present review focuses on the underlying pathomechanisms of PTOA and in particular the behavior and fate of the surviving chondrocytes, comprising chondrocyte metabolism, regulated cell death, and phenotypical changes comprising hypertrophy and senescence. Moreover, possible therapeutic strategies, such as chondroanabolic stimulation, anti-oxidative and anti-inflammatory treatment, as well as novel therapeutic targets are discussed.

Between-Hospital Variation in Revision Rates After Total Hip and Knee Arthroplasty in the Netherlands: Directing Quality-Improvement Initiatives

BACKGROUND

Variation in 1-year revision rates between Dutch hospitals after primary total hip and knee arthroplasty (THA and TKA) may direct quality-improvement initiatives if this variation accurately reflects true hospital differences. The aim of the present study was to assess the extent of variation, both overall and for specific indications, as well as the statistical reliability of ranking hospitals.

METHODS

All primary THAs and TKAs that were performed between January 2014 and December 2016 were included. Observed/expected (O/E) ratios regarding 1-year revision rates were depicted in a funnel plot with 95% control limits to identify outliers based on 1 or 3 years of data, both overall and by specific indication for revision. The expected number was calculated on the basis of patient mix with use of logistic regression models. The statistical reliability of ranking hospitals (rankability) on these outcomes indicates the percentage of total variation that is explained by "true" hospital differences rather than chance. Rankability was evaluated using fixed and random effects models, for overall revisions and specific indications for revision, including 1 versus 3 years of data.

RESULTS

The present study included 86,468 THAs and 73,077 TKAs from 97 and 98 hospitals, respectively. Thirteen hospitals performing THAs were identified as negative outliers (median O/E ratio, 1.9; interquartile range [IQR], 1.5-2.5), with 5 hospitals as outliers in multiple years. Eight negative outliers were identified for periprosthetic joint infection; 4, for dislocation; and 2, for prosthesis loosening. Seven hospitals performing TKAs were identified as negative outliers (median O/E ratio, 2.3; IQR, 2.2-2.8), with 2 hospitals as outliers in multiple years. Two negative outlier hospitals were identified for periprosthetic joint infection and 1 was identified for technical failures. The rankability for overall revisions was 62% (moderate) for THA and 46% (low) for TKA.

CONCLUSIONS

There was large between-hospital variation in 1-year revision rates after primary THA and TKA. For most outlier hospitals, a specific indication for revision could be identified as contributing to worse performance, particularly for THA; these findings are starting points for quality-improvement initiatives.

Focal metallic inlay resurfacing prosthesis in articular cartilage defects: short-term results of 118 patients and 2 different implants

BACKGROUND

The goal of this study was to share our experience with two different inlay metallic implants in the treatment of knee cartilage defects and to analyze their effects on functional scores.

METHODS

This retrospective study included 118 patients operated on for focal full-thickness knee cartilage lesions, who were treated with a focal metallic inlay resurfacing prosthesis. A cobalt-chromium (Co-Cr) resurfacing implant was applied to 73 patients with a knee chondral lesion, and a biosynthetic implant was applied to 45. All patients were evaluated preoperatively and postoperatively using the KOOS, VAS, and Tegner activity scores.

RESULTS

The group with the Co-Cr-resurfacing implant showed a significantly greater improvement (p < 0.001) in the Tegner and VAS scores at the 2-year follow-up examination. The KOOS scores were similar in both groups. Median patient age was similar in both groups. All patients had a follow-up of at least 2 years. The preoperative and postoperative scores were compared and significant improvements (p < 0.001) were observed. The biosynthetic implant had a higher revision rate. In the univariate analysis, age and type of implant were significantly associated with revision surgery. In the multivariate Cox-regression analysis model, the type of implant was significantly associated with revision surgery.

CONCLUSION

All the patients operated with the above-mentioned implants showed significant improvements in pain and activity scores. Despite the overall good clinical results, 17% of patients with a biosynthetic implant and > 6% of patients with Co-Cr-resurfacing implant required revision surgery. Age and implant type were the main risk factors associated with revision.

The impact of chronic kidney disease on postoperative complications in patients undergoing revision total knee arthroplasty: A propensity matched analysis

OBJECTIVES

Though the role of chronic kidney disease (CKD) has been studied previously in primary arthroplasty procedures of the hips and knees, there is a paucity of literature analyzing CKD's impact on surgical outcomes in revision total knee arthroplasty (rTKA) patients. As the number of patients with CKD requiring revision surgery increases, more vigilant pre-operative and post-operative measures can be taken to ensure successful outcomes. This retrospective study sought to 1) determine differences in demographics and preoperative comorbidities of patients with normal or mild CKD and those with moderate/severe CKD and 2) establish moderate/severe CKD as an independent risk factor for complications in the 30-day postoperative period in patients undergoing rTKA.

METHODS

The ACS-NSQIP database was queried for patients who had undergone rTKA from 2005 to 2016. Patient were assigned to one of five CKD severity classes after eGFR calculation and were further stratified into two cohorts: stages 1/2 vs. stages 3/4/5. After propensity matching to generate a matched normal/mild CKD cohort of rTKA patients, univariate and multivariate analyses were used to assess differences and the impact of severe CKD on the risk for complications.

RESULTS

There were significant differences in several demographic features, comorbidities, and complications between the two cohorts upon univariate analyses. Upon multivariate analyses, CKD of moderate/severe/failure status was found to be a significant independent risk factor for acute renal failure (OR 18.097, 95% CI 4.970-65.902, p < 0.001), blood transfusions (OR 1.697, 95% CI 1.500-1.919, p < 0.001), return to the operating room (OR 1.257, 95% CI 1.009-1.566, p = 0.041), extended length of stay (OR 1.707, 95% CI 1.292-2.255, p < 0.001), and mortality (OR 2.165, 95% CI 1.116-4.200, p = 0.022) in the 30-day postoperative period.

CONCLUSION

This current study found moderate/severe CKD to be an independent risk factor for several complications and should guide healthcare professionals for better patient-optimization. Orthopaedic surgeons should factor in CKD severity in the management of patients undergoing rTKA to effectively mitigate the effects of adverse events.

Cartilage Quality (dGEMRIC Index) Following Knee Joint Distraction or High Tibial Osteotomy

OBJECTIVE

High tibial osteotomy (HTO) and knee joint distraction (KJD) are treatments to unload the osteoarthritic (OA) joint with proven success in postponing a total knee arthroplasty (TKA). While both treatments demonstrate joint repair, there is limited information about the quality of the regenerated tissue. Therefore, the change in quality of the repaired cartilaginous tissue after KJD and HTO was studied using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC).

DESIGN

Forty patients (20 KJD and 20 HTO), treated for medial tibiofemoral OA, were included in this study. Radiographic outcomes, clinical characteristics, and cartilage quality were evaluated at baseline, and at 1- and 2-year follow-up.

RESULTS

Two years after KJD treatment, clear clinical improvement was observed. Moreover, a statistically significant increased medial (Δ 0.99 mm), minimal (Δ 1.04 mm), and mean (Δ 0.68 mm) radiographic joint space width (JSW) was demonstrated. Likewise, medial (Δ 1.03 mm), minimal (Δ 0.72 mm), and mean (Δ 0.46 mm) JSW were statistically significantly increased on radiographs after HTO. There was on average no statistically significant change in dGEMRIC indices over two years and no difference between treatments. Yet there seemed to be a clinically relevant, positive relation between increase in cartilage quality and patients' experienced clinical benefit.

CONCLUSIONS

Treatment of knee OA by either HTO or KJD leads to clinical benefit, and an increase in cartilage thickness on weightbearing radiographs for over 2 years posttreatment. This cartilaginous tissue was on average not different from baseline, as determined by dGEMRIC, whereas changes in quality at the individual level correlated with clinical benefit.

Higher Rate of Early Revision Following Primary Total Knee Arthroplasty in Patients Under Age 55: A Cautionary Tale

BACKGROUND

There has been an increased number of total knee arthroplasties (TKAs) performed in young and active patients. Although improved materials have decreased the likelihood of early catastrophic wear, concerns remain with the performance and survivorship of TKA implants in this patient population. The purpose this study is to evaluate perioperative complications, patient-reported outcomes, and implant survivorship of TKAs performed in patients under age 55.

METHODS

We retrospectively reviewed 4259 primary TKAs performed over a 4-year period. There were 741 TKAs in patients under age 55. The primary outcome of interest was rate of revision at 30 days, 1, 2, and 5-year time points. Secondary outcomes included postoperative transfusion rate, length of stay, rate of deep vein thrombosis/pulmonary embolism, need for manipulation under anesthesia, readmission and reoperation within 30 days, as well as patient-reported outcomes.

RESULTS

There were 3518 patients over 55 years and 741 patients under 55 years. Overall, 175 patients required revision (4.1%). Patients under 55 years had significantly higher cumulative revision rate at 1 (3.4% vs 1.8%, P < .001), 2 (5.0% vs 2.4%, P < .001), and 5 years (7.3% vs 3.7%, P < .001). Patients under 55 years had a higher rate of early reoperation. Patients over 55 years required more transfusions and suffered a higher rate of early deep vein thrombosis. Patients over 55 years had significantly greater improvements in Patient Reported Outcome Measurement Information System Global 10 Physical scores at 6 months postoperatively compared to patients under 55 years.

CONCLUSIONS

Despite improvements in TKA implants, young and active patients remained at higher risk of early revision compared to older patients. The data should be used to counsel young prospective TKA patients about the early risk of reoperation and non-wear-related complications.

The efficacy of pre-emptive analgesia on pain management in total knee arthroplasty: a mini-review

Total knee arthroplasty (TKA) is considered a cost-effective and efficacious treatment for patients with end-stage knee arthritis. Meanwhile, TKA has been regarded as one of the most painful orthopaedic surgeries. Pain control after TKA remains a challenging task. Many analgesic innovations are used to reduce the level of pain, but none has been proven to be the optimum choice till now. Multimodal analgesia incorporates the use of analgesic adjuncts with different mechanisms of action to enhance postoperative pain management. This approach is a preferable choice in relieving postoperative pain with minimum side effects. This paper aims to review pre-emptive analgesia for pain management in TKA. We reviewed the application of pre-emptive analgesia, its physiological mechanism, and the techniques.

Does Accelerometer-based Navigation Have Any Clinical Benefit Compared with Conventional TKA? A Systematic Review

BACKGROUND

Accelerometer-based navigation is a handheld navigation tool that was introduced to offer a simpler technique compared with more-cumbersome computer-assisted surgery (CAS). Considering the increasing number of adopters, it seems important to evaluate the potential clinical benefits of this technology compared with conventional TKA.

QUESTIONS/PURPOSES

In this systematic review, we asked: (1) Is accelerometer-based navigation more accurate than conventional TKA? (2) Does accelerometer-based navigation provide better functional outcome than conventional TKA? (3) Does accelerometer-based navigation increase surgical time or decrease the risk of complications or reoperations compared with conventional TKA?

METHODS

This systematic review included all comparative prospective and retrospective studies published in the MEDLINE/PubMed and Cochrane libraries over the last 10 years. Inclusion criteria were all studies in English that compared accelerometer-based navigation with conventional TKA. Eleven studies met these criteria with 621 knees in accelerometer-based navigation group and 677 knees in conventional TKA group. Results related to alignment, objective and subjective functional scores, duration of surgery, complications and reoperations were extracted and compared between accelerometer-based-navigation and conventional TKA. Methodological quality was assessed using Methodological Index for Non-Randomized Studies (MINORS) tool (for nonrandomized control trials) and Cochrane Risk of Bias (for randomized control trials (RCTs). All studies with fair or better quality were included. Four RCTs and six nonrandomized studies comparing accelerometer-based navigation to conventional TKA were found.

RESULTS

Inconsistent evidence on mechanical axis alignment was found, with five of nine studies slightly favoring the accelerometer-based navigation group, and the other four showing no differences between the groups. Only two of eight studies favored accelerometer-based navigation in terms of tibial component alignment in the coronal plane; the other six found no between-group differences. Similarly, mixed results were found regarding other metrics related to component alignment; a minority of studies favored accelerometer-based navigation by a small margin, and most studies found no between-group differences. Only three studies evaluated functional outcome and none of them showed a difference in range of motion or patient-reported outcomes. Most studies, six of seven, found no between-group differences concerning surgical time; one study demonstrated a slight increase in time with accelerometer-based navigation. There were no between-group differences in terms of the risk of complications, which generally were uncommon in both groups, and no reoperations or revisions were reported in either group.

CONCLUSIONS

We found conflicting evidence about whether accelerometer-based navigation reduces the number of coronal-plane outliers or improves alignment to a clinically important degree, and we found no evidence that it improves patient-reported outcomes or reduces the risk of complications or reoperations. Accelerometer-based navigation may increase surgical time. The overall quality of the evidence was low, which suggested that any observed benefits were overestimated. Given the absence of higher-quality evidence demonstrating compelling benefits of this accelerometer-based navigation technology, it should not be widely adopted.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Blood management in fast-track orthopedic surgery: an evidence-based narrative review

BACKGROUND AND PURPOSE

Innovations able to maintain patient safety while reducing the amount of transfusion add value to orthopedic procedures. Opportunities for improvement arise especially in elective procedures, as long as room for planning is available. Although many strategies have been proposed, there is no consensus about the most successful combination. The purpose of this investigation is to identify information to support blood management strategies in fast-track total joint arthroplasty (TJA) pathway, to (i) support clinical decision making according to current evidence and best practices, and (ii) identify critical issues which need further research.

METHODS AND MATERIALS

We identified conventional blood management strategies in elective orthopedic procedures. We performed an electronic search about blood management strategies in fast-track TJA. We designed tables to match every step of the former with the latter. We submitted the findings to clinicians who operate using fast-track surgery protocols in TJA at our research hospital.

RESULTS

Preoperative anemia detection and treatment, blood anticoagulants/aggregants consumption, transfusion trigger, anesthetic technique, local infiltration analgesia, drainage clamping and removals, and postoperative multimodal thromboprophylaxis are the factors which can add best value to a fast-track pathway, since they provide significant room for planning and prediction.

CONCLUSION

The difference between conventional and fast-track pathways does not lie in the contents of blood management, which are related to surgeons/surgeries, materials used and patients, but in the way these contents are integrated into each other, since elective orthopedic procedures offer significant room for planning. Further studies are needed to identify optimal regimens.

Midterm Performance of a Guided-Motion Bicruciate-Stabilized Total Knee System: Results From the International Study of Over 2000 Consecutive Primary Total Knee Arthroplasties

BACKGROUND

The JOURNEY II Bi-Cruciate Stabilizing Total Knee System (BLINDED) is a second-generation guided-motion knee implant that has been used in over 100,000 primary total knee arthroplasties (TKAs) worldwide. However, performance information is limited.

METHODS

Data for 2059 primary TKAs were abstracted at 7 US and 3 European sites. Estimates of cumulative incidence of revision were compared with registry data for cemented posterior-stabilized implants.

RESULTS

Average age was 64.3 years (range, 18-91); 58.5% were females; and 12.3% TKAs were in subjects younger than 55 years. Patellae were resurfaced in 95.9%. Median time since primary TKA was 4.2 years; longest was 6.1 years; and 78.9% were 3 years or more since primary TKA. Of 67 revisions (3.2%), 20 (30%) involved femoral or tibial component removal compared to 42% in the Australian Joint Registry (Australian Orthopedic Association National Joint Replacement Registry). All-component revisions accounted for 15 of 67, femoral component only for 2 of 67, tibial component only for 3 of 67, patellar component with/without tibial insert exchange for 17 of 67, and isolated tibial insert exchange for 30 of 67. In addition, there were 18 reoperations without component exchange. Component revision indications were infection (33%), mechanical loosening (21%), fracture of bone around the joint (16%), and instability (15%). Kaplan-Meier revision estimate was 3.1 and 3.6 per 100 TKAs at 3 and 5 years, respectively, compared to Australian Orthopedic Association National Joint Replacement Registry estimates of 3.1 and 4.1 per 100 TKAs.

CONCLUSION

The revision rate for the second-generation implant was similar to cemented posterior-stabilized registry controls.

The use of bisphosphonates after joint arthroplasty is associated with lower implant revision rate

PURPOSE

This study hypothesized that the use of bisphosphonates (BPs) after total joint arthroplasty (TJA) is associated with a lower implant revision rate. This study aimed (1) to investigate the association between BP use and the revision rate of TJA and (2) to determine the relationship between the medication period and the revision rate of TJA.

METHODS

National Health Insurance Service data on surgeries, medications, diagnoses, and screenings of 50 million Koreans were reviewed. People who underwent TJA in the period from 2002 to 2012 were identified and followed until 2016. During that period, 331,660 patients underwent total knee arthroplasty (TKA), and 56,043 patients underwent total hip arthroplasty (THA). Among them, 8447 knee patients (2.5%) and 2851 hip patients (5.0%) required revision surgery due to aseptic loosening. Demographic data, the duration of BP medication, and comorbidities were identified. The rate of revision surgery according to BP medication was investigated. The extended Cox proportional hazard model was used to evaluate the effect of the medication period.

RESULTS

The rate of TKA revision was 1.4% for BP users and 2.9% for BP non-users (p < 0.001). The THA revision rate was 2.8% and 5.3% for BP users and non-users, respectively (p < 0.001). The hazard ratio (HR) of revision was significantly lower in patients who took BP medication for more than one year (TKA HR = 0.472, 95% CI [0.350-0.637]; THA HR = 0.490, 95% CI [0.247-0.972]) compared to that in short-term users (less than 1 year).

CONCLUSIONS

The use of BPs after TJA was associated with a lower revision rate. The use of BPs for more than one year further reduced the risk of revision. Bisphosphonate use can be highly recommended to reduce the revision rate of TJA.

LEVEL OF EVIDENCE

Retrospective cohort study, Level III.

Influence of Hospital Volume of Procedures by Year on the Risk of Revision of Total Hip and Knee Arthroplasties: A Propensity Score-Matched Cohort Study

The volume of total hip (THA) and knee arthroplasties (TKA) performed in a hospital per year could be an influential factor on the revision of these procedures. The aims of this study were: To obtain comparable cohorts in higher- and lower-volume hospitals; and to assess the association between the hospital volume and the incidence of revision. Data from patients undergoing THA and TKA caused by osteoarthritis and recorded in the Catalan Arthroplasty Register (RACat) between January 2005 and December 2016 were used. The main explanatory variable was hospital volume by year (higher/lower). The cut-off point was fixed, based on previous research, at 50 THA and 125 TKA procedures/year. To obtain comparable populations, a propensity-score matching method (1:1) was used. Patient characteristics prior to and after matching were compared. To assess differences by volume, subhazard ratios (SHRs) from competing risks models were obtained. After matching, 13,772 THA and 36,316 TKA patients remained in the study. Prior to matching, in both joints, significant differences in all confounders were observed between volume groups. After matching, none of them remained significant. Both in THA and TKA, a higher risk of revision in higher-volume hospitals was observed (THA SHR: 1.25, 95%CI: 1.02–1.53; and TKA SHR: 1.29, 95%CI: 1.16–1.44). Unlike other contexts, currently in Catalonia, higher-volume hospitals have a greater risk of revision than lower-volume hospitals. Further research could be valuable to define context-dependent measures to reduce the incidence of revision.

Preoperative bisphosphonate treatment may adversely affect the outcome after shoulder arthroplasty

AIMS

The aim of this study was to investigate the effects of preoperative bisphosphonate treatment on the intra- and postoperative outcomes of arthroplasty of the shoulder. The hypothesis was that previous bisphosphonate treatment would adversely affect both intra- and postoperative outcomes.

PATIENTS AND METHODS

A retrospective cohort study was conducted involving patients undergoing arthroplasty of the shoulder, at a single institution. Two patients with no previous bisphosphonate treatment were matched to each patient who had received this treatment preoperatively by gender, age, race, ethnicity, body mass index (BMI), and type of arthroplasty. Previous bisphosphonate treatment was defined as treatment occurring during the three-year period before the arthroplasty. The primary outcome measure was the incidence of intraoperative complications and those occurring at one and two years postoperatively. A total of 87 patients were included: 29 in the bisphosphonates-exposed (BP⁺) group and 58 in the non-exposed (BP^-) group. In the BP⁺ group, there were 26 female and three male patients, with a mean age of 71.4 years (51 to 87). In the BP^- group, there were 52 female and six male patients, with a mean age of 72.1 years (53 to 88).

RESULTS

Previous treatment with bisphosphonates was positively associated with intraoperative complications (fracture; odds ratio (OR) 39.40, 95% confidence interval (CI) 2.42 to 6305.70) and one-year postoperative complications (OR 7.83, 95% CI 1.11 to 128.82), but did not achieve statistical significance for complications two years postoperatively (OR 3.45, 95% CI 0.65 to 25.28). The power was 63% for complications at one year.

CONCLUSION

Patients who are treated with bisphosphonates during the three-year period before shoulder arthroplasty have a greater risk of intraoperative and one-year postoperative complications compared with those without this previous treatment.