Total Knee Arthroplasty in the Post-Traumatic Knee: Revision Risks and Functional Outcomes Compared to Osteoarthritic Knees. A Report of Primary Procedures From the Dutch Arthroplasty Register.

BACKGROUND: Total knee arthroplasty (TKA) for post-traumatic arthritis (PTA) poses higher challenges and increased risks of complications compared to TKA for osteoarthritis (OA). This study aimed to compare implant survivorships, reasons for revision, and patient-reported outcome measures between OA and PTA as indications for TKA. METHODS: We selected all primary TKAs for PTA or OA between 2007 and 2020 from the Dutch Arthroplasty Register (Landelijke Registratie Orthopedische Interventies). The study included 3,897 TKA procedures for PTA (median follow-up 4.6 years; interquartile range: 2.2, 7.3) and 255,259 procedures for OA (median follow-up 4.7 years; interquartile range 2.2, 7.6). A total of 10,480 revision procedures were performed across both groups (238 in PTA knees; 10,242 in OA knees). We analyzed the prevalence of preoperative comorbidities and postoperative complications, as well as the reasons for revision, and calculated the implant survival rates. RESULTS: The survival revision rate in the OA group was significantly lower at both follow-up moments (5- and 10- years). The likelihood for revision was increased in TKA for PTA compared to TKA for OA (hazards ratio: 1.16 [95% confidence interval 1.02 to 1.33], P = .03). The most common reason for a revision was instability and arthrofibrosis in the PTA group compared to patellar pain for the OA group. CONCLUSION: This study demonstrated an increased risk for revision for any reason in TKA for PTA compared to OA. Revision for instability and arthrofibrosis were more prevalent in the PTA group, while revision for patellar pain was less prevalent compared to TKA for OA.

Validation of the Incidence of Reported Periprosthetic Joint Infections in Total Hip and Knee Arthroplasty in the Dutch Arthroplasty Register.

BACKGROUND: Arthroplasty registers underreport the incidence of periprosthetic joint infections (PJIs). We validated the incidence of reported PJIs in total hip arthroplasties (THAs) and total knee arthroplasties (TKAs) in the Dutch Arthroplasty Register (LROI) using data from the Dutch National Nosocomial Surveillance Network (PREZIES). METHODS: All primary THAs and TKAs from the LROI and all primary THAs and TKAs performed in consenting hospitals from PREZIES between 2012 and 2018 were matched on date of birth, date of surgery, sex, hospital, and type of procedure (THA n = 91,208; TKA n = 80,304). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for PJIs registered in the LROI, using PREZIES as a reference. RESULTS: The incidence of registered PJIs in THAs was 1.2% in PREZIES and 0.5% in the LROI. For TKAs, this was 0.7 and 0.4%, respectively. The PJIs in THAs in the LROI had a sensitivity of 0.32 (confidence interval [CI]: 0.29 to 0.35), specificity of 1.00 (CI: 1.00 to 1.00), PPV of 0.74 (CI: 0.70 to 0.78), and NPV of 0.99 (CI: 0.99 to 0.99). In TKAs, the sensitivity, specificity, PPV, and NPV were 0.38 (CI: 0.34 to 0.42), 1.00 (CI: 1.00 to 1.00), 0.65 (CI: 0.59 to 0.70), and 1.00 (CI: 1.00 to 1.00), respectively. CONCLUSIONS: The LROI captures approximately one-third of the PJIs as revision within one year for infection or resection arthroplasty. The capture rate of PJIs can be improved by including all reoperations without component exchange and nonsurgical treatments with antibiotics only.

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.

Primary reverse total shoulder arthroplasty for fractures requires more revisions than for degenerative conditions 1 year after surgery: an analysis from the Dutch Arthroplasty Register.

BACKGROUND: Although reverse total shoulder arthroplasty (RTSA) is considered a viable treatment strategy for proximal humeral fractures, there is an ongoing discussion of how its revision rate compares with indications performed in the elective setting. First, this study evaluated whether RTSA for fractures conveyed a higher revision rate than RTSA for degenerative conditions (osteoarthritis, rotator cuff arthropathy, rotator cuff tear, or rheumatoid arthritis). Second, this study assessed whether there was a difference in patient-reported outcomes between these 2 groups following primary replacement. Finally, the results of conventional stem designs were compared with those of fracture-specific designs within the fracture group. MATERIALS AND METHODS: This was a retrospective comparative cohort study with registry data from the Netherlands, generated prospectively between 2014 and 2020. Patients (aged ≥ 18 years) were included if they underwent primary RTSA for a fracture (<4 weeks after trauma), osteoarthritis, rotator cuff arthropathy, rotator cuff tear, or rheumatoid arthritis, with follow-up until first revision, death, or the end of the study period. The primary outcome was the revision rate. The secondary outcomes were the Oxford Shoulder Score, EuroQol 5 Dimensions (EQ-5D) score, numerical rating scale score (pain at rest and during activity), recommendation score, and scores assessing change in daily functioning and change in pain. RESULTS: This study included 8753 patients in the degenerative condition group (mean age, 74.3 ± 7.2 years) and 2104 patients in the fracture group (mean age, 74.3 ± 7.8 years). RTSA performed for fractures showed an early steep decline in survivorship: Adjusted for time, age, sex, and arthroplasty brand, the revision risk after 1 year was significantly higher in these patients than in those with degenerative conditions (hazard ratio [HR], 2.50; 95% confidence interval, 1.66-3.77). Over time, the HR steadily decreased, with an HR of 0.98 at year 6. Apart from the recommendation score (which was slightly better within the fracture group), there were no clinically relevant differences in the patient-reported outcome measures after 12 months. Patients who received conventional stems (n = 1137) did not have a higher likelihood of undergoing a revision procedure than those who received fracture-specific stems (n = 675) (HR, 1.70; 95% confidence interval, 0.91-3.17). CONCLUSION: Patients undergoing primary RTSA for fractures have a substantially higher likelihood of undergoing revision within the first year following the procedure than patients with degenerative conditions preoperatively. Although RTSA is regarded as a reliable and safe treatment option for fractures, surgeons should inform patients accordingly and incorporate this information in decision making when opting for head replacement surgery. There were no differences in patient-reported outcomes between the 2 groups and no differences in revision rates between conventional and fracture-specific stem designs.

No Association Between Hospital Volume and Early Second Revision Rate in Revision Total Knee Arthroplasty in the Dutch Orthopaedic Register.

BACKGROUND: Revision knee arthroplasty (R-KA) is rising globally. Technical difficulty of R-KA varies from liner exchange to full revision. Centralization has been shown to reduce mortality and morbidity rates. The present study aimed to evaluate the association between hospital R-KA volume and overall second revision rate, as well as revision rate for different types of revision. METHODS: The R -KAs between 2010 and 2020 with available data on the primary KA in the Dutch Orthopaedic Arthroplasty Register were included. Minor revisions were excluded. Implant data and anonymous patient characteristics were obtained from the Dutch Orthopaedic Arthroplasty Register. Survival analyses and competing risk analysis were performed per volume category (≤12, 13 to 24, or ≥25 cases/year) at 1, 3, and 5 years following R-KA. There were 8,072 R-KA cases available. Median follow-up was 3.7 years (range 0 to 13.7 years). There were a total of 1,460 second revisions (18.1%) at the end of follow-up. RESULTS: There were no statistically significant differences between second revision rates of the three volume groups. Adjusted hazard ratio for second revision were 0.97 (Confidence Interval (CI) 0.86 to 1.11) for hospitals with 13 to 24 cases/year and 0.94 (CI 0.83 to 1.07) with ≥25 cases/year compared to low volume (≤12 cases/year). Type of revision did not influence second revision rate. CONCLUSION: Second revision rate of R-KA does not seem to be dependent on hospital volume or type of revision in the Netherlands. LEVEL OF EVIDENCE: Level IV, Observational registry study.

Association Between Surface Modifications for Biologic Fixation and Aseptic Loosening of Uncemented Total Knee Arthroplasties.

BACKGROUND: Various surface modifications are used in uncemented total knee arthroplasties (TKAs) to enhance bony ingrowth and longevity of implants. This study aimed to identify which surface modifications are used, whether they are associated with different revision rates for aseptic loosening, and which are underperforming compared to cemented implants. METHODS: Data on all cemented and uncemented TKAs used between 2007 and 2021 were obtained from the Dutch Arthroplasty Register. Uncemented TKAs were divided into groups based on their surface modifications. Revision rates for aseptic loosening and major revisions were compared between groups. Kaplan-Meier, Competing-Risk, Log-rank tests, and Cox regression analyses were used. In total, 235,500 cemented and 10,749 uncemented primary TKAs were included. The different uncemented TKA groups included the following: 1,140 porous-hydroxyapatite (HA); 8,450 Porous-uncoated; 702 Grit-blasted-uncoated; and 172 Grit-blasted-Titanium-nitride (TiN) implants. RESULTS: The 10-year revision rates for aseptic loosening and major revision of the cemented TKAs were 1.3 and 3.1%, and for uncemented TKAs 0.2 and 2.3% (porous-HA), 1.3 and 2.9% (porous-uncoated), 2.8 and 4.0% (grit-blasted-uncoated), and 7.9% and 17.4% (grit-blasted-TiN), respectively. Both type of revision rates varied significantly between the uncemented groups (log-rank tests, P < .001, P < .001). All grit-blasted implants had a significantly higher risk of aseptic loosening (P < .01), and porous-uncoated implants had a significantly lower risk of aseptic loosening than cemented implants (P = .03) after 10 years. CONCLUSION: There were 4 main uncemented surface modifications identified, with different revision rates for aseptic loosening. Implants with porous-HA and porous-uncoated had the best revision rates, at least equal to cemented TKAs. Grit-blasted implants with and without TiN underperformed, possibly due to the interaction of other factors.

Increased risk of aseptic loosening for posterior stabilized compared with posterior cruciate-retaining uncemented total knee replacements: a cohort study of 13,667 knees from the Dutch Arthroplasty Registry.

BACKGROUND AND PURPOSE: While registry studies have suggested a higher risk of revision for posterior-stabilized (PS) compared with posterior cruciate-retaining (CR) total knee replacements (TKR) using cement, it is unknown whether this is also the case for uncemented TKR. We aimed to compare the revision rates of PS and CR designs in patients receiving primary uncemented TKR. PATIENTS AND METHODS: Data from the Dutch arthroplasty register (LROI) was analyzed, comprising 12,226 uncemented primary CR TKRs and 750 uncemented PS TKRs registered between 2007 and 2022. Competing risk and multivariable Cox regression analyses were used to compare revision rates, risks of revision, and reasons for revision between groups. Sensitivity analyses were performed to analyze the risk, concerning the 5 most commonly used implants and performing hospitals for each group. RESULTS: Uncemented PS TKRs had higher 10-year revision rates for any reason and aseptic loosening (6.5%, 95% confidence interval [CI] 4.6-9.2 and 3.9%, CI 2.6-6.7) compared with uncemented CR TKRs (4.2%, CI 3.8-4.7 and 1.4%, CI 1.2-1.7). PS TKRs were 1.4 and 2.5 times more likely to be revised for any reason and aseptic loosening, respectively. These results remained consistent after adjustment for age, sex, BMI, previous surgeries, bearing mobility, and surface modification, with sensitivity analyses. CONCLUSION: We found that uncemented PS implants have a higher rate of revision than uncemented CR implants, mainly due to a higher risk of aseptic loosening.

Risk for re-revision and type of antibiotic-loaded bone cement in hip or knee arthroplasty revisions: report of the Dutch Arthroplasty Register.

BACKGROUND AND PURPOSE: High-dose dual antibiotic-loaded bone cement (ALBC) may reduce the risk of revision after total hip and knee replacements. The aim of our study therefore was to determine the risk of re-revision following first time aseptic hip or knee revision using single versus dual ALBC. PATIENTS AND METHODS: Patients from the Dutch Arthroplasty Register treated from 2007 to 2018 with first time cemented aseptic hip (n = 2,529) or knee revisions (n = 7,124) were incorporated into 2 datasets. The primary endpoint of this observational cohort study was subsequent all-cause re-revision. Multivariable Cox proportional hazard and competing risk was analyzed for both groups. RESULTS: There was no difference in re-revision rate (any reason) with single versus dual ALBC (hazard ratio 1.06, 95% confidence interval [CI] 0.83-1.35 for hip and 0.93, CI 0.80-1.07 for knee revisions). The 10-year crude cumulative re-revision rate also showed no differences for single versus dual ALBC use. The crude cumulative 7-year THA re-revision and 9-year TKA re-revision rates did not show any difference in implant survival for common cement types used. CONCLUSION: We could not confirm the potential benefit of using dual ALBC compared with single ALBC for aseptic hip and knee revisions.

No effect of fixation type on early and late mortality after total knee arthroplasty: a Dutch arthroplasty register study.

PURPOSE: Postoperative mortality is commonly reported as outcome measurement after total knee arthroplasty (TKA). Mortality might be influenced by multiple factors including cementation of the prosthesis. Until now, the influence of cementation on early and late mortality after TKA is unknown. The aim of the present study was to determine the effect of fixation on early and late mortality after primary TKA. METHODS: All patients in the Dutch Arthroplasty Register (LROI) with a primary TKA for osteoarthritis were eligible for inclusion. Data collected from 2007 to 2014 with follow-up until January 2020 were used. Survival analysis was performed by using Kaplan-Meier and Cox survival analysis to determine the mortality rate according to fixation. Adjustments were made for age at time of surgery, gender, American Society of Anaesthesiologists class, and year of surgery. RESULTS: In total 108,687 TKA were included for analysis, which comprised 95,857 cemented, 6,140 cementless and 6,690 hybrid TKA. The early and late mortality rate in cemented TKA was statistically not different compared to cementless or hybrid TKA at 30 days, 31-90 days, 91 days-1 year and 1-5 years. The hazard ratio at 30 days was 1.05 (CI 0.49-2.25) for hybrid fixation, and 1.46 (CI 0.74-2.90) for cementless fixation compared to cemented fixation. The 1-5 years hazard ratio was 1.06 (CI 0.96-1.17) and 0.97 (CI 0.87-1.08), respectively. CONCLUSION: Based on register data, method of fixation does not influence early mortality after primary TKA. This suggests that there is no preferred fixation technique for primary TKA based on the mortality rates. LEVEL OF EVIDENCE: IV.

Defining Clinically Meaningful Thresholds for Patient-Reported Outcomes in Knee Arthroplasty.

BACKGROUND: For primary knee arthroplasties, clinically meaningful thresholds of patient-reported outcomes that associate with patient satisfaction have not been defined appropriately. METHODS: In this retrospective study of 26,720 primary total knee replacements registered in the Dutch Arthroplasty Register (2016-2018), receiver operating curve analysis was used to define minimal clinically important changes (MCICs) and patient acceptable symptom states (PASSs) with the anchor satisfaction. Patient-reported outcome measures were pain, European Quality of Life 5 Dimensions, Knee disability and Osteoarthritis Outcome Score, and Oxford Knee Score (OKS). Independent analyses were performed for groups, which showed statistically significant interactions with the (change in) score to achieve satisfaction in logistic regression. RESULTS: In this cohort, 84.9% completed the anchor questions, of whom 71.3% with a satisfaction score ≥8. Good discriminative abilities (area under the receiving operator curve >0.8) for PASS were achieved by OKS ≥38.5, pain in activity ≤2.5, Knee disability and Osteoarthritis Outcome Score ≤33, and Quality of Life-Index ≥0.813. Discriminative abilities for MCIC were not good. If assessed per baseline tercile, discrimination improved (area under the receiving operator curve >0.8) and yielded different MCICs per preoperative tercile (preoperative OKS ≤19: MCIC ≥19.5; pre-OKS 20-27: MCIC ≥14.5; pre-OKS ≥28: MCIC ≥8.5). For MCIC, the tercile method produced an 11% improved accuracy compared to one threshold for every patient. For the PASS scores, tercile-specific did not improve the accuracy of predicting satisfaction. Demographics were not clinically relevant in determining thresholds. CONCLUSION: Estimating the likelihood of satisfaction with surgery is critical in shared decision-making. Patients with more preoperative symptom severity require larger changes to report satisfaction. Both in the clinic and in science, such differences must be considered when predictions of satisfaction are attempted.

Rare primary patellar resurfacing does not lead to more secondary patellar resurfacing: analysis of 70,014 primary total knee arthroplasties in the Dutch Arthroplasty Register (LROI).

BACKGROUND AND PURPOSE: Current literature provides no conclusive evidence in support of a patellar resurfacing vs. non-resurfacing regime. Therefore, we compared the incidence of secondary patellar resurfacing among hospitals using 3 different primary patellar resurfacing regimes in the Netherlands. Secondarily we identified patient and surgical characteristics associated with primary patellar resurfacing and secondary patella resurfacing following non-resurfaced primary total knee arthroplasty (TKA). PATIENTS AND METHODS: We used data from 2014-2016 of the Dutch Arthroplasty Register. Hospitals were divided into rare (0-10%), selective (>10% to 90%), and usually primary patellar resurfacing (>90%) regimes. We performed a logistic regression analysis for associated factors of primary patellar resurfacing in the selective resurfacing subgroup and for secondary patellar resurfacing in the rare resurfacing subgroup. RESULTS: The rate of primary resurfacing was 5.2% for the rare and 36% for the selective patellar resurfacing regimes, with similar secondary patellar resurfacing (1.1% vs. 0.9%). Predictors for primary patellar resurfacing were being female (OR 1.3) and younger (50-59 years, OR 1.4). The PS prosthesis design had a higher OR (4.1) than the CR design. Younger age (50-59 years, OR 1.5) and PS prosthesis (OR 2.7) were significant predictors of secondary patellar resurfacing. Particular surgical systems have a higher rate of primary and secondary patellar resurfacing. INTERPRETATION: Low rates of secondary patellar resurfacing in hospitals with a rare resurfacing regime indicate that this regime does not lead to more secondary patellar resurfacing then selective resurfacing. In the Dutch orthopedic community primary and secondary patellar resurfacing is associated with using a posterior stabilizing design, being younger, and using particular TKA systems.

Impact of the COVID-19 lockdown on patient-reported outcome measures in Dutch hip and knee arthroplasty patients.

BACKGROUND AND PURPOSE: During the first COVID-19 lockdown elective surgery was greatly reduced. Prioritization of patients with greater need and expected benefit in terms of quality of life was advised. The lockdown also potentially affected follow-up outcomes. Therefore, our study compared patient-reported outcome measures (PROMs) retrieved during the lockdown of Dutch primary total hip and knee arthroplasty (THA, TKA) patients with previous years. PATIENTS AND METHODS: We performed cross-sectional analyses using national data from the Dutch Orthopaedic Registry (LROI). All primary elective THA and TKA patients with preoperative or postoperative PROMs (EQ-5D-3L index, OHS/OKS) during the first COVID-19 lockdown between March and July 15, 2020 were included. Patients with PROMs during the same months in 2018 plus 2019 were used as control. Finally, 33,453 THA and 27,335 TKA patients were included. Patient characteristics were compared during versus before the lockdown. Subsequently, the lockdown effect on PROMs scores was analyzed with multivariable linear regression. RESULTS: During the COVID-19 lockdown, THA and TKA patients had a lower age and BMI preoperatively, and more often had surgery in private clinics. Both preoperative PROMs in THA patients, but not in TKA patients, were worse (EQ-5D: Adjusted mean difference (AMD) -0.021, p < 0.001) during the lockdown compared with prior years. Both postoperative PROMs in THA and TKA patients were better during the lockdown (12-month EQ-5D in THA: AMD 0.010, p = 0.003; and in TKA: AMD 0.013, p < 0.001). INTERPRETATION: During the COVID-19 lockdown, THA patients had slightly worse preoperative PROMs, suggesting selection of patients with greater urgency. Postoperative PROMs in both THA and TKA patients differed minimally. Overall, the observed differences were likely not clinically relevant.

Stem retention and survival in revision of anatomical convertible shoulder arthroplasty to reverse arthroplasty: a Dutch registry study.

BACKGROUND: Convertible stem designs allow for stem retention during revision from anatomical to reverse shoulder arthroplasty. In some cases conversion is not possible for example due to excessive soft tissue tensioning. In these cases a total revision is necessary. The primary aim of this Dutch registry study was to evaluate the unforeseen stem reversion percentages in revision of convertible anatomical shoulder arthroplasty to reverse shoulder arthroplasty. METHODS: Shoulder arthroplasties (n = 2834) performed between 2014 and 2016 registered in the Dutch Arthroplasty Registry were selected. In 2016 94% of primary arthroplasties and 92% of revision arthroplasties were registered in the database. Arthroplasties were selected on convertibility. Mean follow-up was 2.4 years. We analysed the number of revisions for convertible and non-convertible designs. Cases with obligatory revisions as periprosthetic joint infections, stem loosening and periprosthetic fractures were excluded. Kaplan-Meier analysis was used to calculate humeral stem survival. Multivariate cox-regression analysis was used to determine risk factors for stem revision. RESULTS: The majority of procedures (respectively 90.9 and 72.1% for the convertible and non-convertible group) concerned a conversion to reverse shoulder arthroplasty (p = .02). In the convertible group, the stem was retained in 29 out of 40 patients (72.5%). Overall implant survival was 94.5% after a mean follow-up of 2.4 years. Hemiartroplasty, fracture as primary indication, previous shoulder surgery and lower age were risk factors for revision. CONCLUSIONS: Although convertible designs are gaining popularity due to their expected advantage in revision arthroplasty, surgeons should be aware that during a revision procedure in 27.5% of the patients an unforeseen stem revision is necessary.

Comparable mid-term revision rates of primary cemented and cementless total knee arthroplasties in 201,211 cases in the Dutch Arthroplasty Register (2007-2017).

PURPOSE: Long-term failure of total knee arthroplasty (TKA) is mostly due to loosening of the prosthesis. In this study, the short- and mid-term revision rates of cemented vs cementless TKAs were investigated. Comparable short- and mid-term survival rates of both fixation methods were expected. METHODS: Data on all cemented and cementless TKAs performed between 2007 and 2017 were retrieved from the Dutch Arthroplasty Register. The cumulative crude incidence of revision of cemented and cementless TKA was calculated. Death was considered a competing risk. Revision rates were compared using multivariable Cox proportional hazard regression analysis. The associations between fixation method and type of revision or reason for revision were tested using logistic regression analyses. RESULTS: In total, 190,651 (94.8%) cemented and 10,560 (5.3%) cementless TKAs were evaluated. Both groups had comparable case characteristics. Cemented TKAs were inserted more often in cases with previous knee surgery compared to cementless TKAs (32% vs 27%). The cumulative incidence of revision after 9 years was 5.5% (CI 5.3-5.6%) for cemented and 5.8% (CI 5.2-6.4%) for cementless TKAs (p = 0.2). Cementless TKAs were more often revised due to loosening of the tibial (27% vs 18%; p < 0.001) or the femoral component (7% vs 5%; p = 0.005) than cemented TKAs. Cemented TKAs were more often revised due to infection (17% vs 9%; p = 0.004) than cementless TKAs. CONCLUSION: In conclusion, cemented and cementless TKAs have comparable short- and mid-term revision rates based on a nationwide register study. LEVEL OF EVIDENCE: III.

Reasons for revision are associated with rerevised total knee arthroplasties: an analysis of 8,978 index revisions in the Dutch Arthroplasty Register.

Background and purpose - From previous studies, we know that clinical outcomes of revision total knee arthroplasty (rTKA) differ among reasons for revision. Whether the prevalence of repeat rTKAs is different depending on the reason for index rTKA is unclear. Therefore, we (1) compared the repeat revision rates between the different reasons for index rTKA, and (2) evaluated whether the reason for repeat rTKA was the same as the reason for the index revision.Patients and methods - Patients (n = 8,978) who underwent an index rTKA between 2010 and 2018 as registered in the Dutch Arthroplasty Register were included. Reasons for revision, as reported by the surgeon, were categorized as: infection, loosening, malposition, instability, stiffness, patellar problems, and other. Competing risk analyses were performed to determine the cumulative repeat revision rates after an index rTKA for each reason for revision.Results - Overall, the cumulative repeat revision rate was 19% within 8 years after index rTKA. Patients revised for infection had the highest cumulative repeat revision rate (28%, 95% CI 25-32) within 8 years after index rTKA. The recurrence of the reason was more common than other reasons after index rTKA for infection (18%), instability (8%), stiffness (7%), and loosening (5%).Interpretation - Poorest outcomes were found for rTKA for infection: over 1 out of 4 infection rTKAs required another surgical intervention, mostly due to infection. Recurrence of other reasons for revision (instability, stiffness, and loosening) was also considerable. Our findings also emphasize the importance of a clear diagnosis before doing rTKA to avert second revision surgeries.

International variation in distribution of ASA class in patients undergoing total hip arthroplasty and its influence on mortality: data from an international consortium of arthroplasty registries.

Background and purpose - A challenge comparing outcomes from total hip arthroplasty between countries is variation in preoperative characteristics, particularly comorbidity. Therefore, we investigated between-country variation in comorbidity in patients based on ASA class distribution, and determined any variation of ASA class to mortality risk between countries.Patients and methods - All arthroplasty registries collecting ASA class and mortality data in patients with elective primary THAs performed 2012-2016 were identified. Survival analyses of the influence of ASA class on 1-year mortality were performed by individual registries, followed by meta-analysis of aggregated data.Results - 6 national registries and 1 US healthcare organization registry with 418,916 THAs were included. There was substantial variation in the proportion of ASA class III/IV, ranging from 14% in the Netherlands to 39% in Finland. Overall, 1-year mortality was 0.93% (95% CI 0.87-1.01) and increased from 0.2% in ASA class I to 8.9% in class IV. The association between ASA class and mortality measured by hazard ratios (HR) was strong in all registries even after adjustment for age and sex, which reduced them by half in all registries. Combined adjusted HRs were 2.0, 6.1, and 22 for ASA class II-IV vs. I, respectively. Associations were moderately heterogeneous across registries.Interpretation - We observed large variation in ASA class distribution between registries, possibly explained by differences in background morbidity and/or international variation in access to surgery. The similar, strong mortality trends by ASA class between countries enhance the relevance of its use as an indicator of comorbidity in international registry studies.

Higher mid-term revision rates of posterior stabilized compared with cruciate retaining total knee arthroplasties: 133,841 cemented arthroplasties for osteoarthritis in the Netherlands in 2007-2016.

Background and purpose - The preference for a cruciate retaining (CR) or posterior stabilized (PS) TKA (total knee arthroplasty) system varies greatly between Dutch hospitals, independent of patient characteristics. We examined mid-term revision rates for men and women of different age categories. Patients and methods - We included all 133,841 cemented fixed-bearing primary CR or PS TKAs for osteoarthritis reported in the Dutch Arthroplasty Register (LROI) in 2007-2016. Revision procedures were defined as minor when only insert and/or patella were revised and as major when fixed components (tibia and femur) were revised or removed. 8-year all-cause revision rates of CR and PS TKAs were calculated using competing-risk analyses. Cox-regression analyses were performed, adjusted for age at surgery, sex, ASA -score, and previous operations. Results - PS TKAs were 1.5 (95% CI 1.4-1.6) times more likely to be revised within 8 years of the primary procedure, compared with CR TKAs. When stratified for sex and age category, 8-year revision rate of PS TKAs in men <60 years was 13% (CI 11-15), compared to 7.2% (CI 6.1-8.5) of CR TKAs. Less prominent differences were found in older men and women. For men <60 years differences were found for minor (CR 1.8% (CI 1.4-2.5); PS 3.7% (CI 3.0-4.7)) and major revisions (CR 4.2% (CI 3.3-5.3); PS 7.0% (CI 5.6-8.7)). Interpretation - Patients who received a cemented fixed-bearing primary PS TKA for osteoarthritis are more likely to undergo either a minor or a major revision within 8 years. This is especially prominent for younger men.

Comparison of the early postoperative outcomes of cementless and cemented medial unicompartmental knee arthroplasty.

Aims: The primary objective of this registry-based study was to compare patient-reported outcomes of cementless and cemented medial unicompartmental knee arthroplasty (UKA) during the first postoperative year. The secondary objective was to assess one- and three-year implant survival of both fixation techniques. Methods: We analyzed 10,862 cementless and 7,917 cemented UKA cases enrolled in the Dutch Arthroplasty Registry, operated between 2017 and 2021. Pre- to postoperative change in outcomes at six and 12 months' follow-up were compared using mixed model analyses. Kaplan-Meier and Cox regression models were applied to quantify differences in implant survival. Adjustments were made for patient-specific variables and annual hospital volume. Results: Change from baseline in the Oxford Knee Score (OKS) and activity-related pain was comparable between groups. Adjustment for covariates demonstrated a minimally greater decrease in rest-related pain in the cemented group (ß = -0.09 (95% confidence interval (CI) -0.16 to -0.01)). Cementless fixation was associated with a higher probability of achieving an excellent OKS outcome (> 41 points) (adjusted odds ratio 1.2 (95% CI 1.1 to 1.3)). The likelihood of one-year implant survival was greater for cemented implants (adjusted hazard ratio (HR) 1.35 (95% CI 1.01 to 1.71)), with higher revision rates for periprosthetic fractures of cementless implants. During two to three years' follow-up, the likelihood of implant survival was non-significantly greater for cementless UKA (adjusted HR 0.64 (95% CI 0.40 to 1.04)), primarily due to increased revision rates for tibial loosening of cemented implants. Conclusion: Cementless and cemented medial UKA led to comparable improvement in physical function and pain reduction during the initial postoperative year, albeit with a greater likelihood of achieving excellent OKS outcomes after cementless UKA. Anticipated differences in early physical function and pain should not be a decisive factor in the choice of fixation technique. However, surgeons should consider the differences in short- and long-term implant survival when deciding which implant to use.

Implant survival of total elbow arthroplasty: analysis of 514 cases from the Dutch Arthroplasty Registry.

The aim of this study is to report the implant survival and factors associated with revision of total elbow arthroplasty (TEA) using data from the Dutch national registry. All TEAs recorded in the Dutch national registry between 2014 and 2020 were included. The Kaplan-Meier method was used for survival analysis, and a logistic regression model was used to assess the factors associated with revision. A total of 514 TEAs were included, of which 35 were revised. The five-year implant survival was 91%. Male sex, a higher BMI, and previous surgery to the same elbow showed a statistically significant association with revision (p < 0.036). Of the 35 revised implants, ten (29%) underwent a second revision. This study reports a five-year implant survival of TEA of 91%. Patient factors associated with revision are defined and can be used to optimize informed consent and shared decision-making. There was a high rate of secondary revisions.

Higher risk of 2-year cup revision of ceramic-on-ceramic versus ceramic-on-polyethylene bearing: analysis of 33,454 primary press-fit total hip arthroplasties registered in the Dutch Arthroplasty Register (LROI).

BACKGROUND AND PURPOSE: The influence of bearing on short-term revision in press-fit total hip arthroplasty (THA) remains under-reported. The aim of this study was to describe 2-year cup revision rates of ceramic-on-ceramic (CoC) and ceramic-on-polyethylene (CoPE). PATIENTS AND METHODS: Primary press-fit THAs with one of the three most used cups available with both CoC or CoPE bearing recorded in the Dutch Arthroplasty Register (LROI) were included (2007-2019). Primary outcome was 2-year cup revision for all reasons. Secondary outcomes were: reasons for revision, incidence of different revision procedures and use of both bearings over time. RESULTS: 2-year Kaplan-Meier cup revision rate in 33,454 THAs (12,535 CoC; 20,919 CoPE) showed a higher rate in CoC (0.67% [95% CI, 0.54-0.81]) compared to CoPE (0.44% [95% CI, 0.34-0.54]) (p = 0.004). Correction for confounders (age, gender, cup type, head size) resulted in a hazard ratio (HR) of 0.64 [95%CI, 0.48-0.87] (p = 0.019). Reasons for cup revision differed only by more cup revision due to loosening in CoC (26.2% vs.1 3.2%) (p = 0.030). For aseptic loosening a revision rate of 0.153% [95% CI, 0.075-0.231] was seen in CoC and 0.058% [95%CI 0.019-0.097] in CoPE (p = 0.007). Correction for head size resulted in a HR of 0.475 [95% CI, 0.197-1.141] (p = 0.096). Incidence of different revision procedures did not differ between bearings. Over time the use of CoPE has increased and CoC decreased. CONCLUSIONS: A higher 2-year cup revision rate in press-fit THA was observed in CoC compared to CoPE. Cup loosening was the only significantly different reason for revision and seen more often in CoC and mostly aseptic. Future randomised controlled trials need to confirm causality, since the early cup revision data provided has the potential to be useful when choosing the bearing in press-fit THA, when combined with other factors like bone quality and patient and implant characteristics.