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Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_9 | Pages 11 - 11
1 Oct 2020
Shanaghan K Carroll KM Jerabek SA Mayman DJ Ast MP Haas SB
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Introduction. Pulmonary embolism (PE) complicates up to 1% of total joint arthroplasties (TJA). Many PE treatment guidelines call for immediate initiation of therapeutic anticoagulation. Options include Xa inhibitors, Enoxaparin, and Warfarin. Deciding between these is a balance of the efficacy and the risks. Little data exists regarding the risks of each of these treatment options for treating PE in arthroplasty patients. Methods. We examined the records of 29,270 patients who underwent a primary total joint arthroplasty (TJA), defined as a unilateral total knee arthroplasty (TKA) (18,987) or total hip arthroplasty (THA) (10,283), between 2/2016 and 12/2018 at our institution and identified 338 (242 TKA, 96 THA) patients who developed an in-hospital PE treated with therapeutic anticoagulation. The patients were treated with therapeutic doses of Xa inhibitors, enoxaparin or warfarin. The type and frequency of complications were determined and classified as major or minor. Major complication included: bleeding requiring surgery, GI bleed requiring treatment, >2 unit transfusion and mortality. Minor complications included wound drainage, bleeding not requiring surgery, and thrombocytopenia. Results. Overall complication rates were high for all treatments. Xa inhibitors had the lowest complication rate at 14% compared to 20% for enoxaparin and 20.7% for warfarin though the difference did not quite reach statistical significance (p=.054). Both major and minor complication were lower with Xa inhibitors, but again the difference was not statistically significant (p=0.67). There was no significant difference in complications between TKA groups (p=0.73) or THA groups (p=0.83). Gender and body mass index were not predictive of major or minor complications. Discussion. Our results demonstrate high complication rates associated with modern therapeutic anticoagulation protocols for perioperative PE following TJA. Patients who receive therapeutic anticoagulation postoperatively are at high risk for complication. Xa inhibitors may decrease these risks, but larger studies are required


The Bone & Joint Journal
Vol. 101-B, Issue 7_Supple_C | Pages 91 - 97
1 Jul 2019
Chalmers BP Weston JT Osmon DR Hanssen AD Berry DJ Abdel MP

Aims. There is little information regarding the risk of a patient developing prosthetic joint infection (PJI) after primary total knee arthroplasty (TKA) when the patient has previously experienced PJI of a TKA or total hip arthroplasty (THA) in another joint. The goal of this study was to compare the risk of PJI of primary TKA in this patient population against matched controls. Patients and Methods. We retrospectively reviewed 95 patients (102 primary TKAs) treated between 2000 and 2014 with a history of PJI in another TKA or THA. A total of 50 patients (53%) were female. Mean age was 69 years (45 to 88) with a mean body mass index (BMI) of 36 kg/m. 2. (22 to 59). In total, 27% of patients were on chronic antibiotic suppression. Mean follow-up was six years (2 to 16). We 1:3 matched these (for age, sex, BMI, and surgical year) to 306 primary TKAs performed in 306 patients with a THA or TKA of another joint without a subsequent PJI. Competing risk with death was used for statistical analysis. Multivariate analysis was followed to evaluate risk factors for PJI in the study cohort. Results. The cumulative incidence of PJI in the study cohort (6.1%) was significantly higher than the matched cohort (2.6%) at ten years (hazard ratio (HR) 3.3; 95% confidence interval 1.18 to 8.97; p = 0.02). Host grade in the study group was not a significant risk factor for PJI. Patients on chronic suppression had a higher rate of PJI (HR 15; p = 0.002), with six of the seven patients developing PJI in the study group being on chronic suppression. The new infecting microorganism was the same as the previous in only two of seven patients. Conclusion. In this matched cohort study, patients undergoing a clean primary TKA with a history of TKA or THA PJI in another joint had a three-fold higher risk of PJI compared with matched controls with ten-year cumulative incidence of 6.1%. The risk of PJI was 15-fold higher in patients on chronic antibiotic suppression; further investigation into reasons for this and mitigation strategies are recommended. Cite this article: Bone Joint J 2019;101-B(7 Supple C):91–97


Bone & Joint Open
Vol. 4, Issue 9 | Pages 682 - 688
6 Sep 2023
Hampton M Balachandar V Charalambous CP Sutton PM

Aims

Aseptic loosening is the most common cause of failure following cemented total knee arthroplasty (TKA), and has been linked to poor cementation technique. We aimed to develop a consensus on the optimal technique for component cementation in TKA.

Methods

A UK-based, three-round, online modified Delphi Expert Consensus Study was completed focusing on cementation technique in TKA. Experts were identified as having a minimum of five years’ consultant experience in the NHS and fulfilling any one of the following criteria: a ‘high volume’ knee arthroplasty practice (> 150 TKAs per annum) as identified from the National joint Registry of England, Wales, Northern Ireland and the Isle of Man; a senior author of at least five peer reviewed articles related to TKA in the previous five years; a surgeon who is named trainer for a post-certificate of comletion of training fellowship in TKA.


The Bone & Joint Journal
Vol. 105-B, Issue 12 | Pages 1286 - 1293
1 Dec 2023
Yang H Cheon J Jung D Seon J

Aims

Fungal periprosthetic joint infections (PJIs) are rare, but their diagnosis and treatment are highly challenging. The purpose of this study was to investigate the clinical outcomes of patients with fungal PJIs treated with two-stage exchange knee arthroplasty combined with prolonged antifungal therapy.

Methods

We reviewed our institutional joint arthroplasty database and identified 41 patients diagnosed with fungal PJIs and treated with two-stage exchange arthroplasty after primary total knee arthroplasty (TKA) between January 2001 and December 2020, and compared them with those who had non-fungal PJIs during the same period. After propensity score matching based on age, sex, BMI, American Society of Anesthesiologists grade, and Charlson Comorbidity Index, 40 patients in each group were successfully matched. The surgical and antimicrobial treatment, patient demographic and clinical characteristics, recurrent infections, survival rates, and relevant risk factors that affected joint survivorship were analyzed. We defined treatment success as a well-functioning arthroplasty without any signs of a PJI, and without antimicrobial suppression, at a minimum follow-up of two years from the time of reimplantation.


Aims

The primary objective of this study was to compare the five-year tibial component migration and wear between highly crosslinked polyethylene (HXLPE) inserts and conventional polyethylene (PE) inserts of the uncemented Triathlon fixed insert cruciate-retaining total knee arthroplasty (TKA). Secondary objectives included clinical outcomes and patient-reported outcome measures (PROMs).

Methods

A double-blinded, randomized study was conducted including 96 TKAs. Tibial component migration and insert wear were measured with radiostereometric analysis (RSA) at three, six, 12, 24, and 60 months postoperatively. PROMS were collected preoperatively and at all follow-up timepoints.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_12 | Pages 16 - 16
1 Oct 2018
Sculco TP Jones C Selemon N Miller A Henry M Sculco PK Nocon AA
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Introduction. Periprosthetic joinTt infection (PJI) remains an uncommon, yet devastating complication of total hip arthroplasty (THA) and total knee arthroplasty (TKA). Debridement with antibiotics and implant retention (DAIR) provides an alternative to staged revision. Chronic infection is considered to be a contraindication to DAIR, however, outcomes stratified by chronicity have not been documented. Methods. We performed a retrospective review of all DAIR cases performed at our institution between 2008–2015. Timeframe to treatment was categorized as acute (< 6 weeks since surgery), chronic (>6 weeks since surgery) or acute hematogenous (previously well-functioning prosthesis). Treatment failure was defined as reoperation during the first 90-days following DAIR. Univariate analysis (Mann-Whitney U and Chi-square; p<0.05) and generalized estimating equations (GEE) were used with multiple comparison adjustment by Tukey-Kramer method (α = 0.05). Results. 282 patients underwent DAIR; 52.8% female; 37.6% THA; 62.4% TKR; mean age: 66.6 (+/−12); mean BMI: 30.3 (+/−7). There were 68 acute (24.1%) patients, 64 (22.7%) chronic and 150 (53.2%) acute hematogenous patients. There was no difference in failure rate between THA and TKA (p=0.09). The data demonstrated that DAIR was more likely to fail in acute (45.6%) compared to chronic (20.3%) or acute hematogenous (25.3%) (OR=4.05; 95 % CI: 2.25 – 7.3, p<0.0001). Staph aureus was the causative organism in 47.1% acute, 18.8% chronic and 28% acute hematogenous. Microbial diagnosis influenced the effect of DAIR results; staph aureus independently increased the failure rate for acute (OR=4.17; 95% CI:1.3–14.3; p=0.02) and chronic (OR=5.89; 95%CI: 1.6–20.0; p=0.01) but not acute hematogenous (OR=1.96; 95% CI: 0.88–4.38; p=0.096). Discussion. 90-day failure of DAIR was higher in the acute compared to chronic or acute hematogenous infection groups. Infection with staph aureus conferred a higher risk of failure for acute and chronic but not for acute hematogenous. DAIR may be more efficacious in chronic PJI than previously considered, particularly for non-staph aureus cases


Bone & Joint Open
Vol. 4, Issue 11 | Pages 881 - 888
21 Nov 2023
Denyer S Eikani C Sheth M Schmitt D Brown N

Aims

The diagnosis of periprosthetic joint infection (PJI) can be challenging as the symptoms are similar to other conditions, and the markers used for diagnosis have limited sensitivity and specificity. Recent research has suggested using blood cell ratios, such as platelet-to-volume ratio (PVR) and platelet-to-lymphocyte ratio (PLR), to improve diagnostic accuracy. The aim of the study was to further validate the effectiveness of PVR and PLR in diagnosing PJI.

Methods

A retrospective review was conducted to assess the accuracy of different marker combinations for diagnosing chronic PJI. A total of 573 patients were included in the study, of which 124 knees and 122 hips had a diagnosis of chronic PJI. Complete blood count and synovial fluid analysis were collected. Recently published blood cell ratio cut-off points were applied to receiver operating characteristic curves for all markers and combinations. The area under the curve (AUC), sensitivity, specificity, and positive and negative predictive values were calculated.


Bone & Joint Research
Vol. 13, Issue 5 | Pages 226 - 236
9 May 2024
Jürgens-Lahnstein JH Petersen ET Rytter S Madsen F Søballe K Stilling M

Aims

Micromotion of the polyethylene (PE) inlay may contribute to backside PE wear in addition to articulate wear of total knee arthroplasty (TKA). Using radiostereometric analysis (RSA) with tantalum beads in the PE inlay, we evaluated PE micromotion and its relationship to PE wear.

Methods

A total of 23 patients with a mean age of 83 years (77 to 91), were available from a RSA study on cemented TKA with Maxim tibial components (Zimmer Biomet). PE inlay migration, PE wear, tibial component migration, and the anatomical knee axis were evaluated on weightbearing stereoradiographs. PE inlay wear was measured as the deepest penetration of the femoral component into the PE inlay.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_12 | Pages 18 - 18
1 Oct 2018
Gehrke T Zahar A Lausmann C Citak M
Full Access

Introduction. Despite several preventive strategies, periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) is still a devastating complication. Early diagnosis and appropriate treatment are crucial to achieve successful infection control, but challenging since there is no test with 100% sensitivity and 100%. Therefore, several national and international guidelines include synovial analysis of joint aspirates as important diagnostic criteria, but cut-off levels for synovial cell count (CC) and polymorphonuclear (granulocyte) percentage (PMN%) are still debatable. The current investigation was performed to analyze the overall accuracy and optimal cut-off of synovial CC and PMN% following total knee (TKA) and total hip arthroplasty (THA). Methods. Between October 2012 and June 2017, all patients with painful TKA or THA, who underwent joint aspiration before revision arthroplasty were included in this retrospective study. From aspirated synovial fluid, leukocyte esterase activity, leukocyte CC and PMN% were determined, and specimens were sent for bacterial culture. A total of 524 preoperative joint aspirations (255 hips, 269 knees) were enrolled for final analysis. For 337 patients, the synovial CC and PMN% could be measured by the laboratory. From those patients, 203 patients were scheduled for aseptic revision, and 134 patients for septic revision arthroplasty according to the MSIS criteria for PJI. Specificity (SP), sensitivity (SE), positive predictive value (PPV), negative predictive and overall accuracy were measured for CC and PMN%. The optimum cut-off value was calculated by the ROC and the value giving the AUC, achieving the best possible level of sensitivity and specificity. Results. The best cut-off level for PJI of all study patients was 2582 leukocytes/μL (Se 80.6%, Sp 85.2%) and a PMN% of 66.1% (Se 80.6%, Sp 83.3%). The chosen cut-off levels for PJI of TKA was 1630 leukocytes/μL (Se 83.6%, Sp 82.2%) and a PMN% of 60.5% (Se 80.3%, Sp 77.1%). The optimal cut-off values for PJI of THA was 3063 leukocytes/μL (Se 78.1%, Sp 80.0%) and a PMN% of 66.1% (Se 82.2%, Sp 82.4%). Conclusions. Synovial cell count and polymorphonuclear percentage are sensitive methods for diagnosing PJI with differences in cut-off levels for THA and TKA. We suggest considering the cut-off levels of CC and PMN% from aspirates of TKA at 1600/μL and 60%, respectively, as possible PJI. For THA, the cut-off levels of CC and PMN% are at 3000/μL and 66%, respectively


The Bone & Joint Journal
Vol. 100-B, Issue 1_Supple_A | Pages 62 - 67
1 Jan 2018
Bedard NA DeMik DE Dowdle SB Callaghan JJ

Aims. The purpose of this study was to evaluate trends in opioid use after unicompartmental knee arthroplasty (UKA), to identify predictors of prolonged use and to compare the rates of opioid use after UKA, total knee arthroplasty (TKA) and total hip arthroplasty (THA). Materials and Methods. We identified 4205 patients who had undergone UKA between 2007 and 2015 from the Humana Inc. administrative claims database. Post-operative opioid use for one year post-operatively was assessed using the rates of monthly repeat prescription. These were then compared between patients with and without a specific variable of interest and with those of patients who had undergone TKA and THA. Results. A total of 4205 UKA patients were analysed. Of these, 1362 patients (32.4%) were users of opioids. Pre-operative opioid use was the strongest predictor of prolonged opioid use after UKA. Opioid users were 1.4 (81.6% versus 57.7%), 3.7 (49.5% versus 13.3%) and 5.5 (35.8% versus 6.5%) times more likely to be taking opioids at one, two and three months post-operatively, respectively (p < 0.05 for all). Younger age and specific comorbidities such as anxiety/depression, smoking, back pain and substance abuse were found to significantly increase the rate of repeat prescription for opioids after UKA. Overall, UKA patients required significantly less opioid prescriptions than patients who had undergone THA and TKA. Conclusion. One-third of patients who undergo UKA are given opioids in the three months pre-operatively. Pre-operative opioid use is the best predictor of increased repeat prescriptions after UKA. However, other intrinsic patient characteristics are also predictive. Cite this article: Bone Joint J 2018;100-B(1 Supple A):62–7


Bone & Joint Open
Vol. 3, Issue 7 | Pages 573 - 581
1 Jul 2022
Clement ND Afzal I Peacock CJH MacDonald D Macpherson GJ Patton JT Asopa V Sochart DH Kader DF

Aims

The aims of this study were to assess mapping models to predict the three-level version of EuroQoL five-dimension utility index (EQ-5D-3L) from the Oxford Knee Score (OKS) and validate these before and after total knee arthroplasty (TKA).

Methods

A retrospective cohort of 5,857 patients was used to create the prediction models, and a second cohort of 721 patients from a different centre was used to validate the models, all of whom underwent TKA. Patient characteristics, BMI, OKS, and EQ-5D-3L were collected preoperatively and one year postoperatively. Generalized linear regression was used to formulate the prediction models.


The Bone & Joint Journal
Vol. 104-B, Issue 2 | Pages 235 - 241
1 Feb 2022
Stone B Nugent M Young SW Frampton C Hooper GJ

Aims

The success of total knee arthroplasty (TKA) is usually measured using functional outcome scores and revision-free survivorship. However, reporting the lifetime risk of revision may be more meaningful to patients when gauging risks, especially in younger patients. We aimed to assess the lifetime risk of revision for patients in different age categories at the time of undergoing primary TKA.

Methods

The New Zealand Joint Registry database was used to obtain revision rates, mortality, and the indications for revision for all primary TKAs performed during an 18-year period between January 1999 and December 2016. Patients were stratified into age groups at the time of the initial TKA, and the lifetime risk of revision was calculated according to age, sex, and the American Society of Anesthesiologists (ASA) grade. The most common indications for revision were also analyzed for each age group.


The Bone & Joint Journal
Vol. 103-B, Issue 11 | Pages 1695 - 1701
1 Nov 2021
Currier JH Currier BH Abdel MP Berry DJ Titus AJ Van Citters DW

Aims

Wear of the polyethylene (PE) tibial insert of total knee arthroplasty (TKA) increases the risk of revision surgery with a significant cost burden on the healthcare system. This study quantifies wear performance of tibial inserts in a large and diverse series of retrieved TKAs to evaluate the effect of factors related to the patient, knee design, and bearing material on tibial insert wear performance.

Methods

An institutional review board-approved retrieval archive was surveyed for modular PE tibial inserts over a range of in vivo duration (mean 58 months (0 to 290)). Five knee designs, totalling 1,585 devices, were studied. Insert wear was estimated from measured thickness change using a previously published method. Linear regression statistical analyses were used to test association of 12 patient and implant design variables with calculated wear rate.


The Bone & Joint Journal
Vol. 103-B, Issue 10 | Pages 1595 - 1603
1 Oct 2021
Magill P Hill JC Bryce L Martin U Dorman A Hogg R Campbell C Gardner E McFarland M Bell J Benson G Beverland D

Aims

In total knee arthroplasty (TKA), blood loss continues internally after surgery is complete. Typically, the total loss over 48 postoperative hours can be around 1,300 ml, with most occurring within the first 24 hours. We hypothesize that the full potential of tranexamic acid (TXA) to decrease TKA blood loss has not yet been harnessed because it is rarely used beyond the intraoperative period, and is usually withheld from ‘high-risk’ patients with a history of thromboembolic, cardiovascular, or cerebrovascular disease, a patient group who would benefit greatly from a reduced blood loss.

Methods

TRAC-24 was a prospective, phase IV, single-centre, open label, parallel group, randomized controlled trial on patients undergoing TKA, including those labelled as high-risk. The primary outcome was indirect calculated blood loss (IBL) at 48 hours. Group 1 received 1 g intravenous (IV) TXA at the time of surgery and an additional 24-hour postoperative oral regime of four 1 g doses, while Group 2 only received the intraoperative dose and Group 3 did not receive any TXA.


Bone & Joint Open
Vol. 2, Issue 8 | Pages 576 - 582
2 Aug 2021
Fuchs M Kirchhoff F Reichel H Perka C Faschingbauer M Gwinner C

Aims

Current guidelines consider analyses of joint aspirates, including leucocyte cell count (LC) and polymorphonuclear percentage (PMN%) as a diagnostic mainstay of periprosthetic joint infection (PJI). It is unclear if these parameters are subject to a certain degree of variability over time. Therefore, the aim of this study was to evaluate the variation of LC and PMN% in patients with aseptic revision total knee arthroplasty (TKA).

Methods

We conducted a prospective, double-centre study of 40 patients with 40 knee joints. Patients underwent joint aspiration at two different time points with a maximum period of 120 days in between these interventions and without any events such as other joint aspirations or surgeries. The main indications for TKA revision surgery were aseptic implant loosening (n = 24) and joint instability (n = 11).


The Bone & Joint Journal
Vol. 103-B, Issue 9 | Pages 1514 - 1525
1 Sep 2021
Scott CEH Holland G Gillespie M Keenan OJ Gherman A MacDonald DJ Simpson AHRW Clement ND

Aims

The aims of this study were to investigate the ability to kneel after total knee arthroplasty (TKA) without patellar resurfacing, and its effect on patient-reported outcome measures (PROMs). Secondary aims included identifying which kneeling positions were most important to patients, and the influence of radiological parameters on the ability to kneel before and after TKA.

Methods

This prospective longitudinal study involved 209 patients who underwent single radius cruciate-retaining TKA without patellar resurfacing. Preoperative EuroQol five-dimension questionnaire (EQ-5D), Oxford Knee Score (OKS), and the ability to achieve four kneeling positions were assessed including a single leg kneel, a double leg kneel, a high-flexion kneel, and a praying position. The severity of radiological osteoarthritis (OA) was graded and the pattern of OA was recorded intraoperatively. The flexion of the femoral component, posterior condylar offset, and anterior femoral offset were measured radiologically. At two to four years postoperatively, 151 patients with a mean age of 70.0 years (SD 9.44) were included. Their mean BMI was 30.4 kg/m2 (SD 5.36) and 60 were male (40%). They completed EQ-5D, OKS, and Kujala scores, assessments of the ability to kneel, and a visual analogue scale for anterior knee pain and satisfaction.


The Bone & Joint Journal
Vol. 103-B, Issue 6 Supple A | Pages 145 - 149
1 Jun 2021
Crawford DA Passias BJ Adams JB Berend KR Lombardi AV

Aims

A limited number of investigations with conflicting results have described perivascular lymphocytic infiltration (PVLI) in the setting of total knee arthroplasty (TKA). The purpose of this study was to determine if PVLI found in TKAs at the time of aseptic revision surgery was associated with worse clinical outcomes and survivorship.

Methods

A retrospective review was conducted on 617 patients who underwent aseptic TKA revision who had histological analysis for PVLI at the time of surgery. Clinical and radiological data were obtained pre- and postoperatively, six weeks postoperatively, and then every year thereafter.


The Bone & Joint Journal
Vol. 103-B, Issue 6 Supple A | Pages 3 - 12
1 Jun 2021
Crawford DA Duwelius PJ Sneller MA Morris MJ Hurst JM Berend KR Lombardi AV

Aims

The purpose is to determine the non-inferiority of a smartphone-based exercise educational care management system after primary knee arthroplasty compared with a traditional in-person physiotherapy rehabilitation model.

Methods

A multicentre prospective randomized controlled trial was conducted evaluating the use of a smartphone-based care management system for primary total knee arthroplasty (TKA) and partial knee arthroplasty (PKA). Patients in the control group (n = 244) received the respective institution’s standard of care with formal physiotherapy. The treatment group (n = 208) were provided a smartwatch and smartphone application. Early outcomes assessed included 90-day knee range of movement, EuroQoL five-dimension five-level score, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) score, 30-day single leg stance (SLS) time, Time up and Go (TUG) time, and need for manipulation under anaesthesia (MUA).


The Bone & Joint Journal
Vol. 103-B, Issue 1 | Pages 113 - 122
1 Jan 2021
Kayani B Tahmassebi J Ayuob A Konan S Oussedik S Haddad FS

Aims

The primary aim of this study was to compare the postoperative systemic inflammatory response in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic-arm assisted total knee arthroplasty (robotic TKA). Secondary aims were to compare the macroscopic soft tissue injury, femoral and tibial bone trauma, localized thermal response, and the accuracy of component positioning between the two treatment groups.

Methods

This prospective randomized controlled trial included 30 patients with osteoarthritis of the knee undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localized knee temperature were collected preoperatively and postoperatively at six hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned postioning of the components in both groups.


The Bone & Joint Journal
Vol. 102-B, Issue 9 | Pages 1167 - 1175
14 Sep 2020
Gromov K Petersen PB Jørgensen CC Troelsen A Kehlet H

Aims

The aim of this prospective multicentre study was to describe trends in length of stay and early complications and readmissions following unicompartmental knee arthroplasty (UKA) performed at eight different centres in Denmark using a fast-track protocol and to compare the length of stay between centres with high and low utilization of UKA.

Methods

We included data from eight dedicated fast-track centres, all reporting UKAs to the same database, between 2010 and 2018. Complete ( > 99%) data on length of stay, 90-day readmission, and mortality were obtained during the study period. Specific reasons for a length of stay of > two days, length of stay > four days, and 30- and 90-day readmission were recorded. The use of UKA in the different centres was dichotomized into ≥ 20% versus < 20% of arthroplasties which were undertaken being UKAs, and ≥ 52 UKAs versus < 52 UKAs being undertaken annually.