Revision of metal-on-metal hip replacements with dual-mobility bearings and acetabular component retention.

Aims: In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component. Methods: Between 2012 and 2020, across two centres, 94 patients underwent revision of Birmingham MoM hip arthroplasties or resurfacings. Mean age was 65.5 years (33 to 87). In 53 patients (56.4%), the acetabular component was retained and dual-mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). Patients underwent follow-up of minimum two-years (mean 4.6 (2.1 to 8.5) years). Results: In the DM group, two (3.8%) patients underwent further surgery: one (1.9%) for dislocation and one (1.9%) for infection. In the AR group, four (9.8%) underwent further procedures: two (4.9%) for loosening of the acetabular component and two (4.9%) following dislocations. There were no other dislocations in either group. In the DM group, operating time (68.4 vs 101.5 mins, p < 0.001), postoperative drop in haemoglobin (16.6 vs 27.8 g/L, p < 0.001), and length of stay (1.8 vs 2.4 days, p < 0.001) were significantly lower. There was a significant reduction in serum metal ions postoperatively in both groups (p < 0.001), although there was no difference between groups for this reduction (p = 0.674 (cobalt); p = 0.186 (chromium)). Conclusion: In selected patients with Birmingham MoM hips, where the acetabular component is well-fixed and in a satisfactory position with no surface damage, the metal head can be exchanged for polyethylene ADM/MDM bearings with retention of the acetabular prosthesis. This presents significant benefits, with a shorter procedure and a lower risk of complications.

Quantification and severity grading of femoral vessel compression by adverse reactions to metal debris in metal-on-metal total hip arthroplasty.

INTRODUCTION: Metal-on-metal (MoM) total hip arthroplasty (THA) may cause adverse reactions to metal debris (ARMD). ARMD causing femoral vessel compression with serious complications has been described in case reports, but the rate of compression by ARMD is not known. This study aims to investigate the rate, and quantify the severity, of femoral vessel compression in MoM hips with ARMD lesions. METHODS: Patients under surveillance for MoM THA investigated with MRI were studied. In patients with confirmed ARMD, femoral artery (FA) and vein (FV) diameters were measured at the point of maximal compression and compared to contralateral vessels. The primary outcome measure was presence or absence of compression. Cases were then classified by compression ratios. Secondary outcome measures were rates of deep vein thrombosis, revision surgery and time to ARMD from index procedure. RESULTS: MRI scans for 436 patients with MoM THA were screened. Of these, 211/436 (48.4%) showed evidence of ARMD. Measurements were obtained on 133/211 (63.0%) patients. The FV was compressed in 102/133 (76.7%) and FA in 58/133 (43.6%), while 31/133 (23.3%) patients had no compression. In FVs, 42 demonstrated mild compression, 39 moderate and 21 severe. In FAs, none were severely compressed, 6 were moderate and 52 showed mild compression. There were 3 DVT cases, 2 in patients with moderate FV compression and 1 in patients without FV compression. Revision rates were highest in patients with severe FV compression (14/21, 66.7%). The mean time for MRI-diagnosed ARMD from index procedure was 8 years and 1 month (range 11 months-14.5 years). CONCLUSIONS: Extra-luminal compression of the femoral vessels was found in >75% of patients with ARMD. Although it is not clear whether revision for femoral vessel compression is required, quantification of FV compression may be useful for surgeons and radiologists considering revision for ARMD.

Low readmission and reattendance rate in day-case total knee arthroplasties.

Aims: The rate of day-case total knee arthroplasty (TKA) in the UK is currently approximately 0.5%. Reducing length of stay allows orthopaedic providers to improve efficiency, increase operative throughput, and tackle the rising demand for joint arthroplasty surgery and the COVID-19-related backlog. Here, we report safe delivery of day-case TKA in an NHS trust via inpatient wards with no additional resources. Methods: Day-case TKAs, defined as patients discharged on the same calendar day as surgery, were retrospectively reviewed with a minimum follow-up of six months. Analysis of hospital and primary care records was performed to determine readmission and reattendance rates. Telephone interviews were conducted to determine patient satisfaction. Results: Since 2016, 301/7350 TKAs (4.1%) in 290 patients at our institution were discharged on the day of surgery. Mean follow-up was 31.4 months (6.2 to 70.0). In all, 28 patients (9.3%) attended the emergency department or other acute care settings within 90 days of surgery, most often with wound concerns or leg swelling; six patients (2.0%) were readmitted. No patients underwent a subsequent revision procedure, and there were no periprosthetic infections. Two patients (0.7%) underwent secondary patella resurfacing, and one patient underwent arthroscopic arthrolysis after previous manipulation under anaesthetic (MUA). Three patients (1.0%) underwent MUA alone. Primary care consultation records, available for 206 patients, showed 16 patients (7.8%) contacted their general practitioner within two weeks postoperatively; two (1.0%) were referred to secondary care. Overall, 115/121 patients (95%) telephoned stated they would have day-case TKA again. Conclusion: Day-case TKA can be safely delivered in the NHS with no additional resources. We found low incidence of contact with primary and secondary care in the postoperative period, and high patient satisfaction.

Hip aspiration culture: analysing data from a single operator series investigating periprosthetic joint infection.

Introduction: We undertook this study to know the sensitivity, specificity and post-test probabilities of hip aspiration when diagnosing periprosthetic hip infections. We also examined "dry tap" (injection with saline and aspiration) results and aspiration volumes. Methods: This is a retrospective cohort study of patients aspirated for suspected periprosthetic joint infection between July 2012 and October 2016. All aspirations were carried out by one trained surgical care practitioner (SCP). All aspirations followed an aseptic technique and fluoroscopic guidance. Aspiration was compared to tissue biopsy taken at revision. Aspiration volumes were analysed for comparison. Results: Between January 2012 and September 2016, 461 hip aspirations were performed by our SCP. Of these 125 progressed to revision. We calculated sensitivity 59 % (confidence interval (CI) 35 %-82 %) and specificity 94 % (CI 89 %-98 %). Pre-test probability for our cohort was 0.14. Positive post-test probability was 0.59 and negative post-test probability 0.06. Aspiration volume for infected ( n = 17 ) and non-infected ( n = 108 ) joints was compared and showed no significant difference. Dry taps were experienced five times; in each instance the dry tap agreed with the biopsy result. Conclusions: Our data show that hip aspiration culture is a highly specific investigation for diagnosing infection but that it is not sensitive. Aspiration volume showed no significant difference between infected and non-infected groups. Each time a joint was infiltrated with saline to achieve a result, the result matched tissue sampling.

Antibiotic-loaded bone cement is associated with a lower risk of revision following primary cemented total knee arthroplasty: an analysis of 731,214 cases using National Joint Registry data.

AIMS: Antibiotic-loaded bone cements (ALBCs) may offer early protection against the formation of bacterial biofilm after joint arthroplasty. Use in hip arthroplasty is widely accepted, but there is a lack of evidence in total knee arthroplasty (TKA). The objective of this study was to evaluate the use of ALBC in a large population of TKA patients. MATERIALS AND METHODS: Data from the National Joint Registry (NJR) of England and Wales were obtained for all primary cemented TKAs between March 2003 and July 2016. Patient, implant, and surgical variables were analyzed. Cox proportional hazards models were used to assess the influence of ALBC on risk of revision. Body mass index (BMI) data were available in a subset of patients. RESULTS: Of 731 214 TKAs, 15 295 (2.1%) were implanted with plain cement and 715 919 (97.9%) with ALBC. There were 13 391 revisions; 2391 were performed for infection. After adjusting for other variables, ALBC had a significantly lower risk of revision for any cause (hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77 to 0.93; p < 0.001). ALBC was associated with a lower risk of revision for all aseptic causes (HR 0.85, 95% CI 0.77 to 0.95; p < 0.001) and revisions for infection (HR 0.84, 95% CI 0.67 to 1.01; p = 0.06). The results were similar when BMI was added into the model, and in a subanalysis where surgeons using only ALBC over the entire study period were excluded. Prosthesis survival at ten years for TKAs implanted with ALBC was 96.3% (95% CI 96.3 to 96.4) compared with 95.5% (95% CI 95.0 to 95.9) in those implanted with plain cement. On a population level, where 100 000 TKAs are performed annually, this difference represents 870 fewer revisions at ten years in the ALBC group. CONCLUSION: After adjusting for a range of variables, ALBC was associated with a significantly lower risk of revision in this registry-based study of an entire nation of primary cemented knee arthroplasties. Using ALBC does not appear to increase midterm implant failure rates. Cite this article: Bone Joint J 2019;101-B:1331-1347.

Improving patient reported outcome measures (PROMs) in total knee replacement by changing implant and preserving the infrapatella fatpad: a quality improvement project.

Patient reported outcome measures (PROMs) were introduced in 2009 to allow patient perspectives to potentially influence change and improvement. In collaboration with the national joint registry (NJR), PROMs data has been examined on a national basis to compare surgical factors in total knee replacement (TKR). Initial results demonstrated there were statistically significant differences in Oxford Knee Score (OKS) when using different brands of implant. Preservation of the infrapatella fatpad (IFP) has also been shown improve outcomes. This led Northumbria Healthcare NHS Foundation Trust to make a mass move to the Zimmer Nexgen TKR and later change surgeons' routine practice to preserving the IFP. The PROMs were recorded pre and six months post operation to obtain improvement scores. The baseline improvement in OKS was 14.0. After changing implant to the Zimmer Nexgen in Plan-Do-Study-Act (PDSA) cycle 1 the average improvement score was 16.7. After implementing default preservation of the IFP in PDSA cycle 2 the average OKS improvement score was 17.3. The results from this project demonstrate a significant improvement in local services after implementing changes based on national and local evaluations. This initiative is an excellent example of improvement by evidence based practice and success of the English National Health Service PROMs scheme.

Pre-operative templating for trauma hemiarthroplasty (Thompson's).

INTRODUCTION: Surgical complications may be avoided by preoperative templating in trauma hemiarthroplasty. MATERIALS AND METHODS: Digital templates for the Stryker™ range of Thompson's prostheses were created and fifty trauma patients that had undergone cemented hemiarthroplasty were retrospectively templated by 2 blinded surgeons. RESULTS: Templating for prosthesis size was highly accurate with excellent Inter and intra-observer reproducibility. Sensitivity for identifying femoral canals too narrow for a Thompsons was 100%. CONCLUSIONS: Templating is a valuable tool and should be standard practice in trauma. We have demonstrated that it is possible to generate custom templates to allow accurate templating.

Complications and survival analyses of hip arthroscopies performed in the national health service in England: a review of 6,395 cases.

PURPOSE: Our study aimed to identify the complications of hip arthroscopies with particular emphasis on the 30-day readmission rate; 90-day deep vein thrombosis (DVT) and pulmonary embolism (PE) rate and mortality rate; revision hip arthroscopy rate; and in particular, survivorship with conversion to total hip replacement (THR) as the endpoint. METHODS: The records of patients undergoing hip arthroscopy were extracted from the administrative hospital admissions database covering all admissions to the National Health Service hospitals in England using ICD-10 (International Statistical Classification of Diseases and Related Health Problems, 10th Revision) and OPCS-4 (Office of Population Censuses and Surveys Classification of Surgical Operations and Procedures, fourth revision) codes. RESULTS: A total of 6,395 hip arthroscopies were included in the study period. The 30-day readmission rate was 0.5%; both the 90-day DVT rate and PE rate were 0.08%; and the 90-day mortality rate was 0.02%. THR was performed in 680 patients (10.6%) at a mean of 1.4 years after the index operation, and 286 patients (4.5%) underwent revision hip arthroscopy at a mean of 1.7 years. Kaplan-Meier survival analysis showed an 8-year survival rate of 82.6% (95% confidence interval [CI], 80.9% to 84.2%), whereas Cox proportional hazard analysis adjusting for age, gender, and Charlson comorbidity score showed an 8-year survival rate of 86%. Female patients had a 1.68 times (95% CI, 1.41 to 2.01) higher risk of conversion to THR than male patients, and patients aged 50 years or older had a 4.65 (95% CI, 3.93 to 5.49) times higher risk of requiring hip replacement than patients younger than 50 years. CONCLUSIONS: In this large series of 6,395 hip arthroscopies looking at the national data from the English National Health Service, our null hypothesis has been supported, and we have determined that the rate of short-term complications, in particular the risk of DVT and PE after this operation, is low. Higher age and female gender are significant predictors of conversion to THR, with Cox proportional hazard analyses showing a survivorship rate of 86% at 8 years after adjustment for confounding variables. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

The effect of triclosan coated sutures on rate of surgical site infection after hip and knee replacement: a protocol for a double-blind randomised controlled trial.

BACKGROUND: 187,000 hip and knee joint replacements are performed every year in the National Health Service (NHS). One of the commonest complications is surgical site infection (SSI), and this represents a significant burden in terms of patient morbidity, mortality and cost to health services around the world. The aim of this randomised controlled trial (RCT) is to determine if the addition of triclosan coated sutures to a standard regimen can reduce the rate of SSI after total knee replacement (TKR) and total hip replacement (THR). METHODS: 2400 patients due to undergo a total hip or knee replacement are being recruited into this two-centre RCT. Participants are recruited before surgery and randomised to either standard care or intervention group. Participants, outcome assessors and statistician are blind to treatment allocation throughout the study. The intervention consists of triclosan coated sutures vs. standard non-coated sutures. The primary outcome is the Health protection Agency (HPA) defined superficial surgical site infection at 30 days. Secondary outcomes include HPA defined deep surgical site infection at 12 months, length of hospital stay, critical care stay, and payer costs. DISCUSSION: To date there are no orthopaedic randomised controlled trials on this scale assessing the effectiveness of a surgical intervention, particularly those that can be translated across the surgical specialities. The results from this trial will inform evidence-based recommendations for suture selection in the management of patients undergoing total hip or knee replacement. If triclosan coated sutures are found to be an effective intervention, implementation into clinical practice could improve long-term outcomes for patients undergoing hip and knee replacement. TRIAL REGISTRATION: Current Controlled Trials ISRCTN 17807356.

Reduced short-term complications and mortality following Enhanced Recovery primary hip and knee arthroplasty: results from 6,000 consecutive procedures.

BACKGROUND AND PURPOSE: Enhanced Recovery (ER) is a well-established multidisciplinary strategy in lower limb arthroplasty and was introduced in our department in May 2008. This retrospective study reviews short-term outcomes in a consecutive unselected series of 3,000 procedures (the "ER" group), and compares them to a numerically comparable cohort that had been operated on previously using a traditional protocol (the "Trad" group). METHODS: Prospectively collected data on surgical endpoints (length of stay (LOS), return to theater (RTT), re-admission, and 30- and 90-day mortality) and medical complications (stroke, gastrointestinal bleeding, myocardial infarction, and pneumonia within 30 days; deep vein thrombosis and pulmonary embolism within 60 days) were compared. Results ER included 1,256 THR patients and 1,744 TKR patients (1,369 THRs and 1,631 TKRs in Trad). The median LOS in the ER group was reduced (3 days vs. 6 days; p = 0.01). Blood transfusion rate was also reduced (7.6% vs. 23%; p < 0.001), as was RTT rate (p = 0.05). The 30-day incidence of myocardial infarction declined (0.4% vs. 0.9%; p = 0.03) while that of stroke, gastrointestinal bleeding, pneumonia, deep vein thrombosis, and pulmonary embolism was not statistically significantly different. Mortality at 30 days and at 90 days was 0.1% and 0.5%, respectively, as compared to 0.5% and 0.8% using the traditional protocol (p = 0.03 and p = 0.1, respectively). INTERPRETATION: This is the largest study of ER arthroplasty, and provides safety data on a consecutive unselected series. The program has achieved a statistically significant reduction in LOS and in cardiac ischemic events for our patients, with a near-significant decrease in return to theater and in mortality rates.

Enhanced recovery program for hip and knee replacement reduces death rate.

BACKGROUND AND PURPOSE: Multimodal techniques can aid early rehabilitation and discharge of patients following primary joint replacement. We hypothesized that this not only reduces the economic burden of joint replacement by reducing length of stay, but also helps in reduction of early complications. PATIENTS AND METHODS: We evaluated 4,500 consecutive unselected total hip replacements and total knee replacements regarding length of hospital stay, mortality, and perioperative complications. The first 3,000 underwent a traditional protocol while the other 1,500 underwent an enhanced recovery protocol involving behavioral, pharmacological, and procedural modifications. RESULTS: There was a reduction in 30-day death rate (0.5% to 0.1%, p = 0.02) and 90-day death rate (0.8% to 0.2%, p = 0.01). The median length of stay decreased from 6 days to 3 days (p < 0.001), resulting in a saving of 5,418 bed days. Requirement for blood transfusion was reduced (23% to 9.8%, p < 0.001). There was a trend of a reduced rate of 30-day myocardial infarction (0.8% to 0.5%. p = 0 .2) and stroke (0.5% to 0.2%, p = 0.2). The 60-day deep vein thrombosis figures (0.8% to 0.6%, p = 0.5) and pulmonary embolism figures (1.2% to 1.1%, p = 0.9) were similar. Re-admission rate remained unchanged during the period of the study (4.7% to 4.8%, p = 0.8). INTERPRETATION: This large observational study of unselected consecutive hip and knee arthroplasty patients shows a substantial reduction in death rate, reduced length of stay, and reduced transfusion requirements after the introduction of a multimodal enhanced recovery protocol.

Acute primary total knee arthroplasty for peri-articular knee fractures in patients over 65 years of age.

Peri-articular knee fractures in osteoporotic or osteoarthritic bone present a challenge to fixation, mobilisation or non-operative management. We present a series of 15 proximal tibial and 11 distal femoral fractures treated with total knee arthroplasty at over mean follow-up period of 38.8 months. The mean age of the patients was 80 years. The choice of the implant and level of constraint was determined as per the nature of injury and preference of the surgeon dealing with the fracture. Patients were allowed rapid mobilisation with immediate full weight-bearing. Good clinical results were achieved with fracture healing, sound fixation and well-aligned flexible knees. Mean Knee Society knee score was 90.2; Knee Society function score was 35.5; Oxford Knee score was 39.5; and Short Form (SF)-36 physical function score was 37.3 and mental score 50.6. Good correlation was noted between Knee society knee score and SF-36 physical function score (Pearson's 0.76, p=0.001), suggesting that generic health would dictate the final function achieved, whilst high knee scores suggest the satisfactory results of the operation. Analogous to arthroplasty for hip fractures, this technique should be considered as a treatment option in elderly peri-articular knee fractures with osteoporosis and/or osteoarthritis.

Acetabular reconstruction using morcellised bone with ring support--medium-term results at three to nine years.

Marked acetabular bone loss in revision hip arthroplasty is challenging. Reconstruction or reinforcement rings may be used in moderate or severe cases with morcellised bone graft to restore bone stock. We report a single surgeon series of 45 hips over a 5-year period. There were 6 complex primary and 39 revision hip arthroplasties with a mean follow-up of 85 months (range: 42-106). Mean age at surgery was 75.6 years (range: 31-95). Contour (Smith & Nephew) titanium acetabular rings were used in all cases. At time of assessment 12 patients had died; of the 30 alive patients (33 hips), 23 patients (26 hips) were available for clinical evaluation. Forty of 45 grafts healed uneventfully with good graft incorporation, 2 were radiologically loose and both were infected. No loosening occurred in the absence of infection. Based on this experience, we recommend this as a safe and effective technique with low complication rates.

Latex-free gloves: safer for whom?

Increasing latex hypersensitivity among patients and health care workers has prompted the development of latex-free surgical gloves. Latex-free gloves must perform equally as the existing latex standard. We analyzed perforation rates in a clinical trial comparing latex and a latex-free alternative during primary hip and knee arthroplasty. The overall latex glove perforation rate was 8.4% compared with 21.6% for the latex-free alternative (chi(2) P < .001). The operation perforation rate for latex gloves was 34.4% compared with 80% for latex-free gloves (chi(2) P < .001). We suggest that the latex-free glove tested cannot provide a reliable barrier between the surgeon and the patient. As such, we question the safety of these gloves and the standards sets by the regulators.

Perioperative management of trauma patients admitted on clopidogrel (Plavix). A survey of orthopaedic departments across the United Kingdom.

BACKGROUND: Clopidogrel (Plavix) is an anti-platelet drug recommended as lifelong treatment by NICE for all patients following stroke, MI, and peripheral vascular disease. It is also indicated for short-term use following cardiac stent insertion. It irreversibly inhibits platelets for up to 7 days. Current recommendations are to stop treatment 7 days before elective surgery. Current evidence shows that delay to surgery more than 4 days in patients with hip fractures increases postoperative mortality. OBJECTIVES: To determine current practice of orthopaedic surgeons in their management of patients taking clopidogrel admitted following a hip fracture to trauma units in the UK with respect to its peri-operative withdrawal and subsequent timing of surgery. To perform a review of the available literature and produce a suggested protocol for the peri-operative management of this rapidly increasing cohort of patients. DESIGN: National postal survey. PARTICIPANTS: Orthopaedic consultants representing each unit receiving trauma patients in the United Kingdom. RESULTS: There was a 57% response rate (139/244 UK trauma units). 41% (56) stop clopidogrel and operate immediately, 11% (15) stop clopidogrel for between 5 and 10 days pre-operatively, 10% (14) stop clopidogrel for 10 days preoperatively, 19% (26) continue clopidogrel and operate immediately, 19% (26) have another protocol. 15% (20) have written departmental guidelines. 2%(3) quoted published evidence for their practice. CONCLUSIONS: This study demonstrates that there are a wide variety of practices, largely based on anecdotal evidence. Most units (85%) have no formal guidelines. There is evidence in the cardiac literature of increased intra-operative bleeding in patients operated on while taking clopidogrel. There is likely to be an exponential rise in such patients presenting to trauma units and further research is required to guide best practice. Following review of the literature we propose an interim protocol for the withdrawal and resumption of clopidogrel peri-operatively in patients with hip fractures.