UNASSIGNED: Arthroplasty registers can provide feedback information on the results of arthroplasties performed by a certain institution or surgeon. The use of real-world data to achieve real-world evidence can help evaluate the performance of the implants used and help counsel our patients. The main objective of our study was to determine the survivorship of the total knee implant we are currently using.
UNASSIGNED: A retrospective cohort study of patients who received a total knee arthroplasty from January 2009 to December 2020 in our hospital was conducted, using data from the Catalan arthroplasty registry and the Catalan health service database. Demographic and surgical data were analysed using the Kaplan-Meier method, log-rank test and Cox proportional hazards models with the R Project software (p < 0.05).
UNASSIGNED: A total of 1336 total knee arthroplasties were included in the study, of which 992 were women. The causes for revision included aseptic loosening (17), infection (29), instability (13), patellar implantation (13), arthrofibrosis (5) and quadriceps tendon rupture (1).The cumulative risk for revision at 5 years using the Kaplan-Meier method was 6.0% and at 10 years 6.5%. Considering gender, this risk was 7.0% and 7.5% at 5 and 10 years, respectively, in women and 3.3% in men, both at 5 and 10 years (p = 0.009). A higher risk for revision in women was seen, which is considered statistically significant (p = 0.012).
UNASSIGNED: Our survivorship results are comparable to those published in the literature, but with a higher revision risk in women that is only statistically significant for the whole group of reoperations and for patellar implantation, but not for the rest of the diagnoses.
UNASSIGNED: Level IV.

BACKGROUND: The number of total hip arthroplasty (THA) is increasing globally, including Japan. The Japanese Orthopaedic Association has been conducting a registry of joint replacement surgery, but there may be a gap between the reported numbers of THA in the registry and the actual number. This study aimed to investigate the exact number of THA and assess the trends in Japan using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB).
METHODS: We downloaded data from 2014 to 2019 from the NDB Open Data. Data on primary THA were extracted, and we calculated the annual number and number for each 10-year age group and sex. We also compared the number and trends between elderly and non-elderly groups.
RESULTS: During the study period, number of THAs increased by approximately 20,000, showing a continuous upward trend. The highest number of THAs were performed on patients in their 60s, except for the years 2014 and 2019. Comparison of the numbers in 2014 and 2019 by age group showed an increase in the number in patients in their 90s (by 2.05 times). There were significantly a greater number of elderly patients (P < 0.001). The number of THAs performed was higher in women than in men (P < 0.001).
CONCLUSIONS: The number of THAs in Japan increased substantially from 2014 to 2019, despite a decrease in population. Significantly higher number of THAs were performed on elderly patients in Japan, which might be due to an aging society. The NDB data is highly valuable for epidemiological research in Japan, as it might enable the early detection of issues occurring during THA, facilitating their prompt integration into daily clinical practice.

OBJECTIVE: The aims of the present study were (1) to evaluate the survival of patellofemoral joint (PFJ) arthroplasty in a large cohort of patients using data obtained from an Italian regional arthroplasty registry and (2) to collect clinical outcomes of a subgroup of patients, with a minimum follow-up of 4 years. The hypotheses were that PFJ arthroplasty is a procedure that had good survival and clinical outcomes, not inferior to those reported in the literature for primary total knee arthroplasty (TKA).
METHODS: The Register of Orthopaedic Prosthetic Implants (RIPO) of Emilia-Romagna (ER) (Italy) database was searched for the inclusion of all PFJ arthroplasties implanted between 2003 and 2019. PFJ arthroplasties were excluded if they were implanted in patients who lived outside of the ER. The survival information was extrapolated from the RIPO considering the partial or total revision of the implant as failure; moreover, a subgroup of patients was contacted and interviewed by telephone to collect clinical outcomes. Descriptive statistics were used to summarise the data. The survival curve was calculated and plotted using the Kaplan-Meier method.
RESULTS: A total of 126 arthroplasties in 114 patients were included in the final analysis (mean age at surgery 60.1 ± 11.5 years old). The main causes of patellofemoral arthroplasty were primary osteoarthritis (88%) and posttraumatic arthritis (7%). The survival was 90.4 ± 30.6 and 78.8 ± 51.5 at 5 and 10 years of follow-up, respectively. At the latest follow-up, 23 implants failed (18.3%). The main cause of revision was osteoarthrosis progression (34.8%). A total of 44 patients were contacted by telephone to collect clinical outcomes: Western Ontario and McMaster Universities Osteoarthritis Index, functional Knee Society Score, Forgotten Joint Score and Oxford Knee Score. These patients reported good to excellent scores at a medium follow-up of 10.3 ± 4.7 years.
CONCLUSIONS: The PFJ showed good survival and clinical outcomes and could be considered a valuable option for patients affected by isolated patellofemoral osteoarthritis.
METHODS: Level IV.

OBJECTIVE: Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.
METHODS: Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications\' number and frequency and recognise differences with national JARs.
RESULTS: One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.
CONCLUSIONS: This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

BACKGROUND: Femoral neck fractures (FNF) are among the most common fractures in Germany and are often treated by hemiarthroplasty (HA). The aim of this study was to compare the occurrence of aseptic revisions after cemented and uncemented HA for the treatment of FNF. Secondly, the rate of pulmonary embolism was investigated.
METHODS: Data collection for this study was performed using the German Arthroplasty Registry (EPRD). HAs after FNF were divided into subgroups stratified by stem fixation (cemented vs uncemented) and paired according to age, sex, BMI, and the Elixhauser score using Mahalanobis distance matching.
RESULTS: Examination of 18,180 matched cases showed a significantly increased rate of aseptic revisions in uncemented HA (p < 0.0001). After 1 month 2.5% of HAs with uncemented stems required an aseptic revision, while 1.5% were reported in cemented HA. After 1 and 3 years\' follow-up 3.9% and 4.5% of uncemented HA and 2.2% and 2.5% of cemented HA needed aseptic revision surgery. In particular, the proportion of periprosthetic fractures was increased in cementless implanted HA (p < 0.0001). During in-patient stays, pulmonary emboli occurred more frequently after cemented HA [0.81% vs 0.53% in cementless HA (OR: 1.53; p = 0.057)].
CONCLUSIONS: For uncemented hemiarthroplasties a statistically significantly increased rate of aseptic revisions and periprosthetic fractures was evident within a time period of 5 years after implantation. During the in-hospital stay, patients with cemented HA experienced an increased rate of pulmonary embolism, but without statistically significant results. Based on the present results, with knowledge of prevention measurements and correct cementation technique, cemented HA should be preferred when using HA in the treatment of femoral neck fractures.
BACKGROUND: The study design of the German Arthroplasty Registry was approved by the University of Kiel (ID: D 473/11).
METHODS: Level III, Prognostic.

Periprosthetic fractures, such as acromial and spine fractures, are known complications following implantation of reverse shoulder arthroplasty (RTSA). The entity of greater tuberosity fractures (GTF) has rarely been studied in the literature. The purpose of this study was to analyze the outcome of postoperative greater tuberosity fractures after RTSA compared to a matched control group. The main findings of this study are that a GTF after RTSA is associated with worse clinical outcome scores (mean absolute CS 50 ± 19 (p = 0.032); SSV 63% ± 26 (p = 0.022); mean force 1 kg ± 2 kg (p = 0.044)) compared with the control group (mean absolute CS 62 ± 21; SSV 77% ± 29; mean force 2 kg ± 2 kg). In terms of postoperative range of motion, the fracture group was significantly worse in terms of external rotation (17° ± 19° vs. 30° ± 19° (p = 0.029)). Internal rotation, flexion, as well as abduction of the shoulder appear to be unaffected (internal rotation GTF 4 ± 2, control group 5 ± 3 (p = 0.138); flexion GTF 102° ± 28°, control group 114° ± 27° (p = 0.160); abduction GTF 109° ± 42°, control group 120° ± 39° (p = 0.317)).

BACKGROUND: The present study aimed to investigate differences in survivorship between medial and lateral unicompartmental knee arthroplasty (UKA) by analyzing the data of an Italian regional registry. The hypothesis was that, according to recent literature, lateral implants have comparable survivorship with regard to the medial implants.
METHODS: The Register of Orthopaedic Prosthetic Implants (RIPO) of Emilia-Romagna (Italy) database was searched for all UKAs between July 1, 2000, and December 31, 2019. For both cohorts, subject demographics and reasons for revision were presented as a percentage of the total cohort. Kaplan-Meier survivorship analysis was performed using revision of any component as the endpoint and survival times of unrevised UKAs taken as the last observation date (December 31, 2019, or date of death).
RESULTS: Patients living outside the region and symmetrical implants (which do not allow the compartment operated to be traced) were excluded. 5571 UKAs implanted on 5172 patients (5215 medial UKAs and 356 lateral UKAs) were included in the study. The survivorship analysis revealed 13 failures out of 356 lateral UKAs (3.7%) at a mean follow-up of 6.3 years and 495 failures out of 5215 medial UKAs (9.5%) at a mean follow-up of 6.7 years. The medial UKAs had a significantly higher risk of failure, with a Hazard Ratio of 2.6 (CI 95% 1.6-4.8; p < 0.001), adjusted for age, gender, weight, and mobility of the insert. Both the groups revealed a good survival rate, with 95.2% of lateral implants and 87.5% of medial implants still in situ at 10 years of follow-up.
CONCLUSIONS: Lateral UKA is a safe procedure showing longer survivorship than medial UKAs (95.2% and 87.5% at 10 years, respectively) in the present study.
METHODS: Level 3, therapeutic study.

OBJECTIVE: The aim of this study was to investigate the rate of revision for distal femoral arthroplasty (DFA) performed as a primary procedure for native knee fractures using data from the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR).
METHODS: Data from the AOANJRR were obtained for DFA performed as primary procedures for native knee fractures from 1 September 1999 to 31 December 2020. Pathological fractures and revision for failed internal fixation were excluded. The five prostheses identified were the Global Modular Arthroplasty System, the Modular Arthroplasty System, the Modular Universal Tumour And Revision System, the Orthopaedic Salvage System, and the Segmental System. Patient demographic data (age, sex, and American Society of Anesthesiologists grade) were obtained, where available. Kaplan-Meier estimates of survival were used to determine the rate of revision, and the reasons for revision and mortality data were examined.
RESULTS: The AOANJRR identified 153 primary DFAs performed for native knee fractures in 151 patients during the study period, with 63.3% of these (n = 97) performed within the last five years. The median follow-up was 2.1 years (interquartile range 0.8 to 4.4). The patient population was 84.8% female (n = 128), with a mean age of 76.1 years (SD 11.9). The cumulative percent revision rate at three years was 10%. The most common reason for revision was loosening, followed by infection. Patient survival at one year was 87.5%, decreasing to 72.8% at three years postoperatively.
CONCLUSIONS: The use of DFA to treat native knee fractures is increasing, with 63.3% of cases performed within the last five years. While long-term data are not available, the results of this study suggest that DFA may be a reasonable option for elderly patients with native knee fractures where fixation is not feasible, or for whom prolonged non-weightbearing may be detrimental. Cite this article: Bone Joint J 2022;104-B(7):894-901.

OBJECTIVE: Existing evidence estimates a twofold risk of venous thromboembolisms (VTEs) if tourniquet is applied during total knee arthroplasties (TKAs). However, this estimate relies on multiple trials with a low number of patients analyzing VTEs as a secondary outcome. We hypothesized that tourniquet-use increases the risk of symptomatic VTE within 90 days of contemporary primary TKA and aimed to use the extensive Danish healthcare registries to quantify this risk.
METHODS: Prospectively collected registry data from Danish patients receiving primary TKAs between 2014 and 2018 were included in the study. Patients were divided by tourniquet-use during surgery. By merging information from four nationwide registries, the study included 44 baseline characteristics with the potential to confound the association between tourniquet-use and VTE. Incidence rate and odds ratios were used to compare the risk of VTE within 90 days of surgery.
RESULTS: 19,804 patients of whom 10,111 (51%) were operated with tourniquet and 9693 (49%) without were included. The mean age (SD) was 70 (9) in both groups and 62% were females in the tourniquet group compared with 61% in the no tourniquet group. The groups were similarly comparable across all other baseline characteristics except type of post-operative thromboprophylaxis, type of anaesthesia, implant fixation, and year of surgery. The 90-days incidence of VTE was 0.77% (95% CI 0.60-0.94) in the tourniquet group compared with 1.10% (95% CI 0.90-1.31) in the no tourniquet group. Following adjustment for the unbalanced confounders, the odds ratio for VTE was 0.77 (95% CI 0.54-1.10) associated with tourniquet-use.
CONCLUSIONS: In contemporary TKAs the rate of VTE within 90 days is low and not significant altered by tourniquet-use. Thus, tourniquet can safely be applied during primary TKA-surgery without jeopardizing the risk of postoperative VTE.
METHODS: II-prospective cohort study.

BACKGROUND: Patella resurfacing remains controversial in primary total knee arthroplasty (TKA).The aim of this study was to investigate if there was a difference in revision rate and reason for revision within 8 years after single brand primary cemented TKA with or without patella resurfacing, using data from the Dutch Arthroplasty Register.
METHODS: All primary TKA surgeries with a posterior stabilized cemented primary NexGen®, between 2010 and 2013 with diagnosis osteoarthritis were analyzed (n = 5911). Multivariate cox regression analyses were performed to analyze differences in revision rate between TKA with or without patella component, and was adjusted for age and previous surgery.
RESULTS: Of 5911 TKA surgeries, 4795 were performed without patella resurfacing (81.1%) and 1116 with patella resurfacing (18.9%). There was a significant difference in patellar problems as reason for revision between patients after primary TKA with patella resurfacing (9.3%) and without patella resurfacing (29.9%) (p = 0.01). This was mostly caused by patellar pain (28.0%). There was no significant difference in cumulative revision rate within between TKA with patella resurfacing and without patella resurfacing.
CONCLUSIONS: In conclusion, 30% of patients who need revision surgery after TKA using NexGen® PS without patella resurfacing the reason for revision is patella related problems, compared to 9% after TKA NexGen® PS with patella resurfacing. There was no difference in cumulative incidence of revision after primary surgery of all TKA\'s using NexGen® PS with or without patella. To reduce the probability of reoperation for patella related problems, our data suggest the patella should be resurface during primary TKA.