Long term follow up of 257 consecutive cementless Oxford medial compartment knee arthroplasties at a non-designer centre.

AIMS: This study aimed to review the survivorship, indication for revision and patient reported outcomes for 257 consecutive Oxford cementless unicompartmental knee arthroplasties (OUKA's) in 238 patients at 12-14 years post-operatively. METHODS: Patients underwent surgery between April 2008 and October 2010 by two non-design surgeons including their learning curve. The 5-year clinical and radiological outcomes have already been reported. Oxford knee scores (OKS) were recorded at 1, 5 and 12-14 years with delayed review a result of the COVID-19 pandemic. Revision indication and imaging were reviewed. RESULTS: Revision was required in 28 OUKA's (10.9%) with a 10-year cumulative survival of 93.0%, reducing to 78.8% at 14 years. 59 patients had died prior to this review and 24 were not contactable. Those not contactable had electronic records reviewed to ensure they did not have a revision elsewhere. Half of the revisions were for progression of lateral compartment arthritis (14/28). Four of 6 cases with a full revision for polyethylene wear may have benefited from a bearing exchange instead. OKSs in non-revised patients were good (median score 38, IQR 30-44) with no significant deterioration noted from 5 to 12-14 years. CONCLUSIONS: Cementless OUKA in this series had a long-term survival rate comparable to other OUKA's outside of the designer centre. OKSs remain good for those patients not revised. Progression of lateral compartment arthritis was the primary reason for revision with no revisions for component loosening or bearing spinout. Ideally UKA patients who experience problems should be under the care of revisions surgeons who perform UKA. Improving patient selection and understanding of the pathophysiology of lateral disease progression, remain crucial to improve the long-term survivorship of OUKA.

Socioeconomic deprivation is associated with worse health-related quality of life and greater opioid analgesia use while waiting for hip and knee arthroplasty.

Aims: The overall aim of this study was to determine the impact of deprivation with regard to quality of life, demographics, joint-specific function, attendances for unscheduled care, opioid and antidepressant use, having surgery elsewhere, and waiting times for surgery on patients awaiting total hip arthroplasty (THA) and total knee arthroplasty (TKA). Methods: Postal surveys were sent to 1,001 patients on the waiting list for THA or TKA in a single Northern Ireland NHS Trust, which consisted of the EuroQol five-dimension five-level questionnaire (EQ-5D-5L), visual analogue scores (EQ-VAS), and Oxford Hip and Knee Scores. Electronic records determined prescriptions since addition to the waiting list and out-of-hour GP and emergency department attendances. Deprivation quintiles were determined by the Northern Ireland Multiple Deprivation Measure 2017 using postcodes of home addresses. Results: Overall, 707 postal surveys were returned, of which 277 (39.2%) reported negative "worse than death" EQ-5D scores and 219 (21.9%) reported the consumption of strong opioids. Those from the least deprived quintile 5 had a significantly better EQ-5D index (median 0.223 (interquartile range (IQR) -0.080 to 0.503) compared to those in the most deprived quintiles 1 (median 0.049 (IQR -0.199 to 0.242), p = 0.004), 2 (median 0.076 (IQR -0.160 to 0.277; p = 0.010), and 3 (median 0.076 (IQR-0.153 to 0.301; p = 0.010). Opioid use was significantly greater in the most deprived quintile 1 compared to all other quintiles (45/146 (30.8%) vs 174/809 (21.5%); odds ratio 1.74 (95% confidence interval 1.18 to 2.57; p = 0.005). Conclusion: More deprived patients have worse health-related quality of life and greater opioid use while waiting for THA and TKA than more affluent patients. For patients awaiting surgery, more information and alternative treatment options should be available.

Reoperation risk of periprosthetic fracture after primary total hip arthroplasty using a collared cementless or a taper-slip cemented stem.

Aims: The aim of this study was to determine both the incidence of, and the reoperation rate for, postoperative periprosthetic femoral fracture (POPFF) after total hip arthroplasty (THA) with either a collared cementless (CC) femoral component or a cemented polished taper-slip (PTS) femoral component. Methods: We performed a retrospective review of a consecutive series of 11,018 THAs over a ten-year period. All POPFFs were identified using regional radiograph archiving and electronic care systems. Results: A total of 11,018 THAs were implanted: 4,952 CC femoral components and 6,066 cemented PTS femoral components. Between groups, age, sex, and BMI did not differ. Overall, 91 patients (0.8%) sustained a POPFF. For all patients with a POPFF, 16.5% (15/91) were managed conservatively, 67.0% (61/91) underwent open reduction and internal fixation (ORIF), and 16.5% (15/91) underwent revision. The CC group had a lower POPFF rate compared to the PTS group (0.7% (36/4,952) vs 0.9% (55/6,066); p = 0.345). Fewer POPFFs in the CC group required surgery (0.4% (22/4,952) vs 0.9% (54/6,066); p = 0.005). Fewer POPFFs required surgery in males with a CC than males with a PTS (0.3% (7/2,121) vs 1.3% (36/2,674); p < 0.001). Conclusion: Male patients with a PTS femoral component were five times more likely to have a reoperation for POPFF. Female patients had the same incidence of reoperation with either component type. Of those having a reoperation, 80.3% (61/76) had an ORIF, which could greatly mask the size of this problem in many registries.

Are Patients With Morbid Obesity at Increased Risk of Pulmonary Embolism or Proximal Deep Vein Thrombosis After Lower Limb Arthroplasty? A Large-database Study.

BACKGROUND: Whether increased BMI is associated with an increased risk of venous thromboembolism (VTE) is controversial. Despite this, BMI > 40 kg/m 2 remains a common cutoff for lower limb arthroplasty eligibility. Current United Kingdom national guidelines list obesity as a risk factor for VTE, but these are based on evidence that has largely failed to differentiate between potentially minor (distal deep vein thrombosis [DVT]), and more harmful (pulmonary embolism [PE] and proximal DVT) diagnoses. Determining the association between BMI and the risk of clinically important VTE is needed to improve the utility of national risk stratification tools. QUESTIONS/PURPOSES: (1) In patients undergoing lower limb arthroplasty, is BMI 40 kg/m 2 or higher (morbid obesity) associated with an increased risk of PE or proximal DVT within 90 days of surgery, compared with patients with BMI less than 40 kg/m 2 ? (2) What proportion of investigations ordered for PE and proximal DVT were positive in patients with morbid obesity who underwent lower limb arthroplasty compared with those with BMI less than 40 kg/m 2 ? METHODS: Data were collected retrospectively from the Northern Ireland Electronic Care Record, a national database recording patient demographics, diagnoses, encounters, and clinical correspondence. Between January 2016 and December 2020, 10,217 primary joint arthroplasties were performed. Of those, 21% (2184 joints) were excluded; 2183 were in patients with multiple arthroplasties and one had no recorded BMI. All 8033 remaining joints were eligible for inclusion, 52% of which (4184) were THAs, 44% (3494) were TKAs, and 4% (355) were unicompartmental knee arthroplasties; all patients had 90 days of follow-up. The Wells score was used to guide the investigations. Indications for CT pulmonary angiography for suspected PE included pleuritic chest pain, reduced oxygen saturations, dyspnea, or hemoptysis. Indications for ultrasound scans for suspected proximal DVT included leg swelling, pain, warmth, or erythema. Distal DVTs were recorded as negative scans because we do not treat them with modified anticoagulation. The division of categories was set at BMI 40 kg/m 2 , a common clinical cutoff used in surgical eligibility algorithms. Patients were grouped according to WHO BMI categories to assess for the following confounding variables: sex, age, American Society of Anesthesiologists grade, joint replaced, VTE prophylaxis, grade of operative surgeon, and implant cement status. RESULTS: We found no increase in the odds of PE or proximal DVT in any WHO BMI category. When comparing patients with BMI less than 40 kg/m 2 with those with a BMI of 40 kg/m 2 or higher, there was no difference in the odds of PE (0.8% [58 of 7506] versus 0.8% [four of 527]; OR 1.0 [95% CI 0.4 to 2.8]; p > 0.99) or proximal DVT (0.4% [33 of 7506] versus 0.2% [one of 527]; OR 2.3 [95% CI 0.3 to 17.0]; p = 0.72). Of those who received diagnostic imaging, 21% (59 of 276) of CT pulmonary angiograms and 4% (34 of 718) of ultrasounds were positive for patients with BMI less than 40 kg/m 2 compared with 14% (four of 29; OR 1.6 [95% CI 0.6 to 4.5]; p = 0.47) and 2% (one of 57; OR 2.7 [95% CI 0.4 to 18.6]; p = 0.51) for patients with BMI 40 kg/m 2 or higher. There was no difference in the percentage of CT pulmonary angiograms ordered (4% [276 of 7506] versus 5% [29 of 527]; OR 0.7 [95% CI 0.5 to 1.0]; p = 0.07) or ultrasounds ordered (10% [718 of 7506] versus 11% [57 of 527]; OR 0.9 [95% CI 0.7 to 1.2]; p = 0.49) for BMI less than 40 kg/m 2 and BMI 40 kg/m 2 or higher. CONCLUSION: Increased BMI should not preclude individuals from lower limb arthroplasty based on suspected risk of clinically important VTE. National VTE risk stratification tools should be based on evidence assessing clinically relevant VTE (specifically, proximal DVT, PE, or death of thromboembolism) only. LEVEL OF EVIDENCE: Level III, therapeutic study.

The painful truth of waiting for hip and knee arthroplasty in Northern Ireland.

Aims: The aim of this study was to report health-related quality of life (HRQoL) and joint-specific function in patients waiting for total hip or knee arthroplasty surgery (THA or TKA) in Northern Ireland, compared to published literature and a matched normal population. Secondary aims were to report emergency department (ED) and out-of-hours general practitioner (OOH GP) visits, new prescriptions of strong opioids, and new prescriptions of antidepressants while waiting. Methods: This was a cohort study of 991 patients on the waiting list for arthroplasty in a single Northern Ireland NHS trust: 497 on the waiting list for ≤ three months; and 494 waiting ≥ three years. Postal surveys included the EuroQol five-dimension five-level questionnaire (EQ-5D-5L), visual analogue scores (EQ-VAS), and Oxford Hip and Knee scores to assess HRQoL and joint-specific function. Electronic records determined prescriptions since addition to the waiting list and patient attendances at OOH GP/EDs. Results: Overall, 712/991 (71.8%) responded at ≤ three months for THA (n = 164) and TKA (n = 199), and ≥ three years for THA (n = 88) and TKA (n = 261). The median EQ-5D-5L score in those waiting ≤ three months was 0.155 (interquartile range (IQR) -0.118 to 0.375) and 0.189 (IQR -0.130 to 0.377) for ≥ three years. Matched controls had a median EQ-5D-5L 0.837 (IQR 0.728 to 1.000). Compared to matched controls, EQ-5D-5L scores were significantly lower in both waiting cohorts (p < 0.001) with significant differences found in every domain. Negative scores, indicating a state "worse than death", were present in 40% at ≤ three months and 38% at ≥ three years. Patients waiting ≥ three years had significantly more opioid (28.4% vs 15.2%; p < 0.001) and antidepressant prescriptions (15.2% vs 9.9%; p = 0.034) and significantly more joint-related attendances at unscheduled care (11.7% vs 0% with ≥ one ED attendance (p < 0.001) and (25.5% vs 2.5% ≥ one OOH GP attendance (p < 0.001)). Conclusion: Patients on waiting lists in Northern Ireland are severely disabled with the worst HRQoL and functional scores studied. The lack of deterioration in EQ-5D-5L and joint-specific scores between patients waiting ≤ three months and ≥ three years likely reflects floor effects of these scores. Prolonged waits were associated with increased dependence on strong opiates, depression, and attendances at unscheduled care.

Decision regret after primary hip and knee replacement surgery.

BACKGROUND: Decision regret (DR) is a recognised patient centered outcome measure following a therapeutic intervention. This study aimed to measure DR following primary total hip and knee arthroplasty (THA/TKA), to assess for differences between these patients and explore possible contributory factors. METHOD: DR was measured using the DR scale in a group of THA and TKA patients, between February 2017 and December 2018, who had made a decision to have joint replacement surgery within the previous year and were able to reflect on their outcomes. RESULTS: On analysis a significantly greater proportion of TKA patients reported moderate or severe (Mod/Sev) DR [17.1% (56/328)] compared to THA patients [4.8% (18/376)]. Conversely, a significantly reduced proportion of TKA patients reported having No DR [42.1% (138/328)] compared to THA patients [66.7% (251/376)]. On multivariate logistic regression analysis joint replacement type (TKA/THA) and change in Oxford score were significant predictors of DR with gender, age, BMI and ASA grade not significantly associated. TKA patients were more than twice as likely to have Mod/Sev DR compared THA patients (Odds Ratio = 2.33 (95% CI 1.24-4.39)). Patients with poorer improvements in pain and function 1-year post-operatively (measured by Oxford scores) reported greater levels of DR. CONCLUSION: TKA patients were significantly more likely to report greater levels of DR 1-year following surgery compared to THA patients. For both TKA and THA patients, greater levels of DR were associated with poorer Oxford scores. The use of decision aids to reduce post-operative DR in joint replacement patients should be examined especially for knee replacement patients.

Survivorship of 500 Cementless Total Knee Arthroplasties in Patients Under 55 Years of Age.

BACKGROUND: With respect to survivorship following total knee arthroplasty (TKA), joint registries consistently demonstrate higher revision rates for both genders in those aged less than 55 years. The present study analyzed the survivorship of 500 cementless TKAs performed in this age group in a high-volume primary joint unit where cementless TKA has traditionally been used for the majority of patients. METHODS: This was a retrospective review of 500 consecutive TKAs performed in patients aged less than 55 years between March 1994 and April 2017. The primary outcome measures for the study were survivorship and all-cause revisions. Secondary outcome measures included nonrevision procedures, clinical, functional, and radiological outcomes. RESULTS: An all-cause survival rate of 98.4% and an aseptic survival rate of 99.2% at a median time of 10.7 years (interquartile range 7.3-14.9, range 0.2-27.7) were found. Four patents were revised for infection, 2 for stiffness, 1 for aseptic loosening of the tibial component, and 1 for a patella that was resurfaced for anterior knee pain. Thirty four patients (6.8%) had a nonrevision procedure with manipulation under anesthetic accounting for 27. On a multivariate analysis, preoperative range of motion and female gender were negatively associated with postoperative range of motion (P < .001 and P = .003, respectively). Sixty seven patients (17.3%) had radioluscent lines and on a multivariate analysis, there were no significant predictors of radiolucent lines. CONCLUSION: Cementless TKA in the young patient can achieve excellent clinical and functional outcomes. At a median of 10.7 years, aseptic revision rates are exceptionally low at 0.8% for the entire cohort.

Is Cementless Total Knee Arthroplasty Safe in Women Over 75 Y of Age?

BACKGROUND: Cementless total knee arthroplasty (TKA) is the subject of renewed interest. Previous concerns about survivorship have been addressed and there is an appeal in terms of biological fixation and surgical efficiency. However, even surgeon advocates have concerns about the risk of marked subsidence when using this technology in older patients at risk for osteoporosis. METHODS: This was a retrospective analysis of 1,000 consecutive fully cementless mobile bearing TKAs performed at a single institution on women over 75 years of age who had postoperative and 1-year x-rays. The primary outcome was the incidence of subsidence. RESULTS: There were three asymptomatic cases with definite subsidence and change in alignment. In a fourth symptomatic case, the femoral component subsided into varus and the tibia into valgus, thus maintaining alignment which facilitated nonoperative treatment in a 92-year-old. Overall, at 1 year, there were two- liner revisions for infection without recurrence. Five patients had further surgery, of which three were washouts and two were for periprosthetic fractures sustained postoperatively within 1 year. Seven patients had further anesthesia, of which five were manipulations and two were nonrecurrent closed reductions for spinouts. CONCLUSION: Cementless TKA did not have a high risk of subsidence in this at-risk population. In the hands of experienced surgeons, these procedures can be used safely irrespective of bone quality.

The Influence of Orthopedic Surgery on Circulating Metabolite Levels, and their Associations with the Incidence of Postoperative Delirium.

The mechanisms underlying the occurrence of postoperative delirium development are unclear and measurement of plasma metabolites may improve understanding of its causes. Participants (n = 54) matched for age and gender were sampled from an observational cohort study investigating postoperative delirium. Participants were ≥65 years without a diagnosis of dementia and presented for primary elective hip or knee arthroplasty. Plasma samples collected pre- and postoperatively were grouped as either control (n = 26, aged: 75.8 ± 5.2) or delirium (n = 28, aged: 76.2 ± 5.7). Widespread changes in plasma metabolite levels occurred following surgery. The only metabolites significantly differing between corresponding control and delirium samples were ornithine and spermine. In delirium cases, ornithine was 17.6% higher preoperatively, and spermine was 12.0% higher postoperatively. Changes were not associated with various perioperative factors. In binary logistic regression modeling, these two metabolites did not confer a significantly increased risk of delirium. These findings support the hypothesis that disturbed polyamine metabolism is an underlying factor in delirium that warrants further investigation.

A conservative approach to dislocation following total hip arthroplasty: a review of 8606 hips.

PATIENTS AND METHODS: We present the data on 8606 total hip arthroplasty (THA) procedures carried out in 7818 patients through a posterior approach between 1998 and 2017. RESULTS: 218 hips (2.5%) suffered at least 1 dislocation with dislocation rates declining from 6.2% from 1998 to 2002 to 1.5% from 2003 to 2017. Overall, 92 hips (1.06%) required revision surgery but of these, only 5 (0.06%) had a full revision of both components with the remaining 87 requiring intervention only on the acetabular side. None have had a pseudo-arthrosis; none were left dislocated and all remain stable to date. CONCLUSIONS: In patients who have a second dislocation within 3 months of their primary surgery we recommend a spica or long leg cylinder cast to reduce the need for revision surgery. We propose an algorithm to manage instability with less aggressive operative treatment in this often-elderly patient population with the potential for less physiological insult and significant cost savings.

Can patients with mild post-operative hyponatraemia following elective arthroplasty be discharged safely? A large-scale service evaluation suggests they can.

BACKGROUND: Post-operative hyponatraemia is common following arthroplasty. Clinical hyponatraemia guidelines lack detail on when treatment is necessary, and there is a paucity of literature to guide best practice. METHODS: Data were collected within retrospective service evaluations over two time periods in a single high throughput joint unit. The hospital's electronic database identified 1000 patients who were admitted electively between February 2012 and June 2013 and again between November 2018 and April 2019 for primary total hip, total knee or uni-compartmental knee arthroplasty. Hyponatraemia and non-hyponatraemia groups were compared. Logistic regression analysis was used to identify independent predictors of post-operative hyponatraemia, length of stay (LOS), re-attendance or re-admission to hospital. RESULTS: Between 2012-2013 and 2018-2019, 32.1% and 25.7% of patients, respectively, developed post-operative hyponatraemia (serum sodium (s[Na]) ≤135 mmol/L). Those with post-operative hyponatraemia were significantly older, weighed less, were more comorbid and had lower pre-operative sodium. Multivariate analysis showed that increased age, knee surgery and lower pre-operative s[Na] independently predicted post-operative hyponatraemia. Post-operative hyponatraemia did not independently predict LOS, re-attendance or re-admission to hospital, within 90 days, in either cohort. CONCLUSION: Post-operative hyponatraemia is common and may be a marker of pre-operative vulnerability. In these cohorts, it was not independently associated with LOS, re-attendance or re-admission to hospital. We suggest that otherwise well patients with mild hyponatraemia can be safely discharged earlier than is often the case and may not require extensive investigation. Further examination and research is required to develop a pre-operative approach to predict which patients will develop significant post-operative hyponatraemia.

The impact of an enhanced recovery programme on length of stay and post-discharge resource usage following hip and knee arthroplasty : a service evaluation and cost analysis.

AIMS: The aim of this study is to assess the impact of a pilot enhanced recovery after surgery (ERAS) programme on length of stay (LOS) and post-discharge resource usage via service evaluation and cost analysis. METHODS: Between May and December 2019, 100 patients requiring hip or knee arthroplasty were enrolled with the intention that each would have a preadmission discharge plan, a preoperative education class with nominated helper, a day of surgery admission and mobilization, a day one discharge, and access to a 24/7 dedicated helpline. Each was matched with a patient under the pre-existing pathway from the previous year. RESULTS: Mean LOS for ERAS patients was 1.59 days (95% confidence interval (CI) 1.14 to 2.04), significantly less than that of the matched cohort (3.01 days; 95% CI 2.56 to 3.46). There were no significant differences in readmission rates for ERAS patients at both 30 and 90 days (six vs four readmissions at 30 days, and nine vs four at 90 days). Despite matching, there were significantly more American Society of Anesthesiologists (ASA) grade 3 patients in the ERAS cohort. There was a mean cost saving of £757.26 (95% CI £-1,200.96 to £-313.56) per patient. This is despite small increases in postoperative resource usage in the ERAS patients. CONCLUSION: ERAS represents a safe and effective means of reducing LOS in primary joint arthroplasty patients. Implementation of ERAS principles has potential financial savings and could increase patient throughput without compromising care. In elective care, a preadmission discharge plan is key. Cite this article: Bone Jt Open 2021;2(11):966-973.

Oral tranexamic acid for an additional 24 hours postoperatively versus a single preoperative intravenous dose for reducing blood loss in total knee arthroplasty: results of a randomized controlled trial (TRAC-24).

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. RESULTS: Between July 2016 and July 2018, 552 patients were randomized to either Group 1 (n = 241), Group 2 (n = 243), or Group 3 (n = 68), and 551 were included in the final analysis. The blood loss did differ significantly between the two intervention groups (733.5 ml (SD 384.0) for Group 1 and 859.2 ml (SD 363.6 ml) for Group 2; mean difference -125.8 ml (95% confidence interval -194.0 to -57.5; p < 0.001). No differences in mortality or thromboembolic events were observed in any group. CONCLUSION: These data support the hypothesis that in TKA, a TXA regime consisting of IV 1 g perioperatively and four oral 1 g doses over 24 hours postoperatively significantly reduces blood loss beyond that achieved with a single IV 1 g perioperative dose alone. TXA appears safe in patients with history of thromboembolic, cardiovascular, and cerebrovascular disease. Cite this article: Bone Joint J 2021;103-B(10):1595-1603.

Prevalence, risk factors, and complications associated with hyponatraemia following elective primary hip and knee arthroplasty.

BACKGROUND: Hyponatraemia, defined as a serum sodium [Na] concentration below 135 mmol/L, is common following surgery. As inpatient peri-operative stays shorten, there is a need to recognise pre-operative risk factors for post-operative hyponatraemia and complications associated with a peri-operative drop in Na. This audit aimed to investigate the prevalence of, risk factors for, and complications associated with hyponatraemia following elective primary hip and knee arthroplasty. METHODS: Data were collected within a retrospective audit of inpatient complications and unplanned reattendance or readmission at hospital in consecutive elective primary hip and knee arthroplasty patients in a single high throughput elective primary joint unit. The hospital's electronic database identified 1000 patients who were admitted electively between February 2012 and June 2013 under the care of a single consultant orthopaedic surgeon for either total hip arthroplasty, total knee arthroplasty, or uni-compartmental knee arthroplasty. Groups were compared using appropriate tests, including chi-square analysis (or Fisher's exact test), Mann-Whitney U test, Kruskal-Wallis test, and Wilcoxin signed-rank test. Logistic regression analysis was used to determine factors associated with hyponatraemia. RESULTS: Of the total 1000 patients, 217 (21.7%) developed post-operative hyponatraemia. Of these, 177 (81.6%) had mild (Na 130-134 mmol/L), 37 (17.1%) had moderate (Na 125-129 mmol/L), and 3 (1.4%) had severe (Na < 125 mmol/L) hyponatraemia. In multivariate analysis, age, pre-operative Na, and fasting glucose on day 1 remained significantly associated with having hyponatraemia post-operatively. There were no significant differences in reattendance at emergency departments and/or readmission within 90 days between those who had post-operative hyponatraemia whilst in hospital (39/217 = 18.0%) and those who did not (103/783 = 13.2%), or between those who were discharged with hyponatraemia (18/108 = 16.7%) and those discharged with normal Na (124/880 = 14.1%). CONCLUSION: Approximately one fifth of elective joint arthroplasty patients had post-operative hyponatraemia. In these patients, older age, lower pre-operative Na and higher fasting glucose predicted post-operative hyponatraemia. We found no evidence that those discharged with hyponatraemia had more reattendance at emergency departments or readmission to hospital. We suggest that otherwise well patients with mild hyponatraemia can safely be discharged and followed up in the community.

Oral tranexamic acid for an additional 24 hours postoperatively versus a single preoperative intravenous dose for reducing blood loss in total hip arthroplasty: results of a randomized controlled trial (TRAC-24).

AIMS: A typical pattern of blood loss associated with total hip arthroplasty (THA) is 200 ml intraoperatively and 1.3 l in the first 48 postoperative hours. Tranexamic acid (TXA) is most commonly given as a single preoperative dose only and is often withheld from patients with a history of thromboembolic disease as they are perceived to be "high-risk" with respect to postoperative venous thromboembolism (VTE). The TRanexamic ACid for 24 hours trial (TRAC-24) aimed to identify if an additional 24-hour postoperative TXA regime could further reduce blood loss beyond a once-only dose at the time of surgery, without excluding these high-risk patients. METHODS: TRAC-24 was a prospective, phase IV, single centre, open label, parallel group, randomized controlled trial (RCT) involving patients undergoing primary unilateral elective THA. The primary outcome measure was the indirect calculated blood loss (IBL) at 48 hours. The patients were randomized into three groups. Group 1 received 1 g intravenous (IV) TXA at the time of surgery and an additional oral regime for 24 hours postoperatively, group 2 only received the intraoperative dose, and group 3 did not receive any TXA. RESULTS: A total of 534 patients were randomized, with 233 in group 1, 235 in group 2, and 66 in group 3; 92 patients (17.2%) were considered high-risk. The mean IBL did not differ significantly between the two intervention groups (848.4 ml (SD 463.8) for group 1, and 843.7 ml (SD 478.7) for group 2; mean difference -4.7 ml (95% confidence interval -82.9 to 92.3); p = 0.916). No differences in mortality or incidence of VTE were observed between any group. CONCLUSION: The addition of oral TXA for 24 hours postoperatively does not reduce blood loss beyond that achieved with a single 1 g IV perioperative dose alone. There may be a clinically relevant difference in patients with a normal BMI, which warrants further investigation. Critically, there were no safety issues in patients with a history of thromboembolic, cardiovascular, or cerebrovascular disease. Cite this article: Bone Joint J 2021;103-B(7):1197-1205.

Metabolomics and computational analysis of the role of monoamine oxidase activity in delirium and SARS-COV-2 infection.

Delirium is an acute change in attention and cognition occurring in ~ 65% of severe SARS-CoV-2 cases. It is also common following surgery and an indicator of brain vulnerability and risk for the development of dementia. In this work we analyzed the underlying role of metabolism in delirium-susceptibility in the postoperative setting using metabolomic profiling of cerebrospinal fluid and blood taken from the same patients prior to planned orthopaedic surgery. Distance correlation analysis and Random Forest (RF) feature selection were used to determine changes in metabolic networks. We found significant concentration differences in several amino acids, acylcarnitines and polyamines linking delirium-prone patients to known factors in Alzheimer's disease such as monoamine oxidase B (MAOB) protein. Subsequent computational structural comparison between MAOB and angiotensin converting enzyme 2 as well as protein-protein docking analysis showed that there potentially is strong binding of SARS-CoV-2 spike protein to MAOB. The possibility that SARS-CoV-2 influences MAOB activity leading to the observed neurological and platelet-based complications of SARS-CoV-2 infection requires further investigation.

Are patient-reported outcomes the same following second-side surgery in primary hip and knee arthroplasty?

AIMS: Up to one in five patients undergoing primary total hip (THA) and knee arthroplasty (TKA) require contralateral surgery. This is frequently performed as a staged procedure. This study aimed to determine if outcomes, as determined by the Oxford Hip Score (OHS) and Knee Score (OKS) differed following second-side surgery. METHODS: Over a five-year period all patients who underwent staged bilateral primary THA or TKA utilizing the same type of implants were studied. Eligible patients had both preoperative and one year Oxford scores and had their second procedure completed within a mean (2 SDs) of the primary surgery. Patient demographics, radiographs, and OHS and OKS were analyzed. RESULTS: A total of 236 patients met the inclusion criteria, of which 122 were THAs and 114 TKAs. The mean age was 66.5 years (SD 9.4), with a 2:1 female:male ratio. THAs showed similar significant improvements in outcomes following first- and second-side surgery, regardless of sex. In contrast for TKAs, although male patients demonstrated the same pattern as the THAs, female TKAs displayed significantly less improvement in both OKS and its pain component following second-side surgery. CONCLUSION: Female patients undergoing second-side TKA showed less improvement in Oxford and pain scores compared to the first-side. This difference in outcome following second-side surgery did not apply to male patients undergoing TKA, or to either sex undergoing THA. Cite this article: Bone Jt Open 2021;2(4):243-254.

Ten-year outcomes following a cohort of ASR XL total hip arthroplasties.

AIMS: To determine the outcome at 10 years of a cohort of ASR XL total hip arthroplasties (THAs) and reasons for revision. METHODS: Between November 2005 and May 2007, 122 ASR XL THAs were implanted. All patients had a routine review at 6 weeks and 1 year, followed by a review in 2009 because of clinical concern and thereafter annual review up to 10 years with MRI. Review also included functional scores, radiographs, pain scores and blood metal ions. RESULTS: 67 (54.9%) ASR XLs had been revised by 11.1 years. Reasons for revision included pain (89.6%), high levels of cobalt and chromium ions (50.7%) and radiographic or MRI changes (80.6%). All 3 factors were present in 23 (34.3%). Pain at 1 year did not predict revision, but pain at the 2009 review did. At 10 years the revised patients had an average Oxford Hip Score (OHS) of 25.38 (12-42) and the non-revised 23.61 (2-21), the difference was not significant (p = 0.48). 3 patients (4.5%) have had a further revision; 2 for a previously unrevised stem and the other for instability. CONCLUSIONS: Our arthroplasty care practitioner service allowed us to identify increased pain and stop using the ASR XL over 3 years before the implant was recalled. The revised patients had similar functional outcome to those unrevised. Poorly performing implants need to be identified earlier.

Prolonged length of stay (PLOS) in a high-volume arthroplasty unit.

INTRODUCTION: The enhanced recovery after surgery (ERAS) concept in arthroplasty surgery has led to a reduction in postoperative length of stay in recent years. Patients with prolonged length of stay (PLOS) add to the burden of a strained NHS. Our aim was to identify the main reasons. METHODS: A PLOS was arbitrarily defined as an inpatient hospital stay of four days or longer from admission date. A total of 2,000 consecutive arthroplasty patients between September 2017 and July 2018 were reviewed. Of these, 1,878 patients were included after exclusion criteria were applied. Notes for 524 PLOS patients were audited to determine predominant reasons for PLOS. RESULTS: The mean total length of stay was 4 days (1 to 42). The top three reasons for PLOS were social services, day-before-surgery admission, and slow to mobilize. Social services accounted for 1,224 excess bed days, almost half (49.2%, 1,224/2,489) of the sum of excess bed days. CONCLUSION: A preadmission discharge plan, plus day of surgery admission and mobilization on the day of surgery, would have the potential to significantly reduce length of stay without compromising patient care.Cite this article: Bone Joint Open 2020;1-8:488-493.