The incidence and risk factors for abnormal postoperative blood tests following primary total joint replacement.

Aims: We aim to evaluate the usefulness of postoperative blood tests by investigating the incidence of abnormal results following total joint replacement (TJR), as well as identifying preoperative risk factors for abnormal blood test results postoperatively, especially pertaining to anaemia and acute kidney injury (AKI). Methods: This is a retrospective cohort study of patients who had elective TJR between January and December 2019 at a tertiary centre. Data gathered included age at time of surgery, sex, BMI, American Society of Anesthesiologists (ASA) grade, preoperative and postoperative laboratory test results, haemoglobin (Hgb), white blood count (WBC), haematocrit (Hct), platelets (Plts), sodium (Na+), potassium (K+), creatinine (Cr), estimated glomerular filtration rate (eGFR), and Ferritin (ug/l). Abnormal blood tests, AKI, electrolyte imbalance, anaemia, transfusion, reoperation, and readmission within one year were reported. Results: The study included 2,721 patients with a mean age of 69 years, of whom 1,266 (46.6%) were male. Abnormal postoperative bloods were identified in 444 (16.3%) patients. We identified age (≥ 65 years), female sex, and ASA grade ≥ III as risk factors for developing abnormal postoperative blood tests. Preoperative haemoglobin (≤ 127 g/dl) and packed cell volume (≤ 0.395 l/l) were noted to be significant risk factors for postoperative anaemia, and potassium (≤ 3.7 mmol/l) was noted to be a significant risk factor for AKI. Conclusion: The costs outweigh the benefits of ordering routine postoperative blood tests in TJR patients. Clinicians should risk-stratify their patients and have a lower threshold for ordering blood tests in patients with abnormal preoperative haemoglobin (≤ 127 g/l), blood loss > 300 ml, chronic kidney disease, ASA grade ≥ III, and clinical concern.

Greater trochanteric pain syndrome: focused shockwave therapy versus an ultrasound guided injection: a randomised control trial.

BACKGROUND: Greater trochanteric pain syndrome (GTPS) is a common problem with an incidence of 1.8-5.6 per 1000 population. Physiotherapy, anti-inflammatories, corticosteroid injections and surgery have all been described in the management of GTPS, with limited, temporal success. Extracorporeal shockwave therapy (ESWT) has been proposed as a potential non-invasive management option for this difficult presentation. METHOD: We ran a prospective, 2-arm, single-blinded, randomised control trial comparing focused shockwave therapy (f-ESWT) to an ultrasound guided corticosteroid injection. Primary outcome measure was the visual analogue pain score. Secondary outcome measures included the Harris Hip Score (HHS) and Trendelenburg test for function; SF-36 for quality of life (QoL); and a Likert scale question for subjective assessment of symptom improvement. RESULTS: 104 patients (10 males and 94 females), of mean age 61.5 years were recruited. 53 were randomised to receive ESWT and 51 to receive an image-guided injection. 11 patients were lost to follow-up. There were no significant differences in baseline scores between groups.At 3 months, pain, function and QoL scores had improved in both groups but were not statistically significant. The Trendelenburg test was significantly improved in the f-ESWT group with 80% patients being negative compared to 20% at baseline (p < 0.001).At 12 months, across all outcomes, the ESWT group had significantly improved scores compared to the injection group; VAS 37.1 versus 55.0 (p = 0.007, 95% confidence interval [CI], 6.3-30.8), HHS 69.7 versus 57.5 (p = 0.002, 95% CI, -20.0 to -4.6) and SF-36 52.4 versus 47.7 (p = 0.048, 95% CI, -9.31 to -0.04). The improvement in Trendelenburg test was maintained in the ESWT group, but the injection group had reverted to baseline (p < 0.001). CONCLUSIONS: We have shown f-ESWT is an effective treatment for patients with GTPS. We would advocate f-ESWT as an effective non-invasive treatment modality for this challenging patient population.Trial Registration No. ISRCTN8338223.

Risk factors associated with revision for prosthetic joint infection after hip replacement: a prospective observational cohort study.

BACKGROUND: The risk of prosthetic joint infection (PJI) is influenced by patient, surgical, and health-care factors. Existing evidence is based on short-term follow-up. It does not differentiate between factors associated with early onset caused by the primary intervention from those associated with later onset more likely to result from haematogenous spread. We aimed to assess the overall and time-specific associations of these factors with the risk of revision due to PJI after primary total hip replacement. METHODS: We did a prospective observational cohort study analysing 623 253 primary hip procedures performed between April 1, 2003, and Dec 31, 2013, in England and Wales and recorded the number of procedures revised because of PJI. We investigated the associations between risk factors and risk of revision for PJI across the overall follow-up period using Poisson multilevel models. We reinvestigated the associations by post-operative time periods (0-3 months, 3-6 months, 6-12 months, 12-24 months, >24 months) using piece-wise exponential multilevel models with period-specific effects. Data were obtained from the National Joint Registry linked to the Hospital Episode Statistics data. FINDINGS: 2705 primary procedures were subsequently revised for an indication of PJI between 2003 and 2014, after a median (IQR) follow up of 4·6 years (2·6-7·0). Among the factors associated with an increased revision due to PJI there were male sex (1462 [1·2‰] of 1 237 170 male-years vs 1243 [0·7‰] of 1 849 691 female-years; rate ratio [RR] 1·7 [95% CI 1·6-1·8]), younger age (739 [1·1‰] of 688 000 person-years <60 years vs 242 [0·6‰] of 387 049 person-years ≥80 years; 0·7 [0·6-0·8]), elevated body-mass index (BMI; 941 [1·8‰] 517 278 person-years with a BMI ≥30 kg/m2vs 272 [0·9‰] of 297 686 person-years with a BMI <25 kg/m2; 1·9 [1·7-2·2]), diabetes (245 [1·4‰] 178 381 person-years with diabetes vs 2120 [1·0‰] of 2 209 507 person-years without diabetes; 1·4 [1·2-1·5]), dementia (5 [10·1‰] of 497 person-years with dementia at 3 months vs 311 [2·6‰] of 120 850 person-years without dementia; 3·8 [1·2-7·8]), previous septic arthritis (22 [7·2‰] of 3055 person-years with previous infection vs 2683 [0·9‰] of 3 083 806 person-years without previous infection; 6·7 [4·2-9·8]), fractured neck of femur (66 [1·5‰] of 43 378 person-years operated for a fractured neck of femur vs 2639 [0·9‰] of 3 043 483 person-years without a fractured neck of femur; 1·8 [1·4-2·3]); and use of the lateral surgical approach (1334 [1·0‰] of 1 399 287 person-years for lateral vs 1242 [0·8 ‰] of 1 565 913 person-years for posterior; 1·3 [1·2-1·4]). Use of ceramic rather than metal bearings was associated with a decreased risk of revision for PJI (94 [0·4‰] of 239 512 person-years with ceramic-on-ceramic bearings vs 602 [0·5‰] of 1 114 239 peron-years with metal-on-polyethylene bearings at ≥24 months; RR 0·6 [0·4-0·7]; and 82 [0·4‰] of 190 884 person-years with ceramic-on-polyethyene bearings vs metal-on-polyethylene bearings at ≥24 months; 0·7 [0·5-0·9]). Most of these factors had time-specific effects. The risk of revision for PJI was marginally or not influenced by the grade of the operating surgeon, the absence of a consultant surgeon during surgey, and the volume of procedures performed by hospital or surgeon. INTERPRETATION: Several modifiable and non-modifiable factors are associated with the risk of revision for PJI after primary hip replacement. Identification of modifiable factors, use of targeted interventions, and beneficial modulation of some of these factors could be effective in reducing the incidence of PJI. It is important for clinicians to consider non-modifiable factors and factors that exhibit time-specific effects on the risk of PJI to counsel patients appropriately preoperatively. FUNDING: National Institute for Health Research.

One- and two-stage surgical revision of peri-prosthetic joint infection of the hip: a pooled individual participant data analysis of 44 cohort studies.

One-stage and two-stage revision strategies are the two main options for treating established chronic peri-prosthetic joint infection (PJI) of the hip; however, there is uncertainty regarding which is the best treatment option. We aimed to compare the risk of re-infection between the two revision strategies using pooled individual participant data (IPD). Observational cohort studies with PJI of the hip treated exclusively by one- or two-stage revision and reporting re-infection outcomes were retrieved by searching MEDLINE, EMBASE, Web of Science, The Cochrane Library, and the WHO International Clinical Trials Registry Platform; as well as email contact with investigators. We analysed IPD of 1856 participants with PJI of the hip from 44 cohorts across four continents. The primary outcome was re-infection (recurrence of infection by the same organism(s) and/or re-infection with a new organism(s)). Hazard ratios (HRs) for re-infection were calculated using Cox proportional frailty hazards models. After a median follow-up of 3.7 years, 222 re-infections were recorded. Re-infection rates per 1000 person-years of follow-up were 16.8 (95% CI 13.6-20.7) and 32.3 (95% CI 27.3-38.3) for one-stage and two-stage strategies respectively. The age- and sex-adjusted HR of re-infection for two-stage revision was 1.70 (0.58-5.00) when compared with one-stage revision. The association remained consistently absent after further adjustment for potential confounders. The HRs did not vary importantly in clinically relevant subgroups. Analysis of pooled individual patient data suggest that a one-stage revision strategy may be as effective as a two-stage revision strategy in treating PJI of the hip.

One-stage or two-stage revision surgery for prosthetic hip joint infection--the INFORM trial: a study protocol for a randomised controlled trial.

BACKGROUND: Periprosthetic joint infection (PJI) affects approximately 1% of patients following total hip replacement (THR) and often results in severe physical and emotional suffering. Current surgical treatment options are debridement, antibiotics and implant retention; revision THR; excision of the joint and amputation. Revision surgery can be done as either a one-stage or two-stage operation. Both types of surgery are well-established practice in the NHS and result in similar rates of re-infection, but little is known about the impact of these treatments from the patient's perspective. The main aim of this randomised controlled trial is to determine whether there is a difference in patient-reported outcome measures 18 months after randomisation for one-stage or two-stage revision surgery. METHODS/DESIGN: INFORM (INFection ORthopaedic Management) is an open, two-arm, multi-centre, randomised, superiority trial. We aim to randomise 148 patients with eligible PJI of the hip from approximately seven secondary care NHS orthopaedic units from across England and Wales. Patients will be randomised via a web-based system to receive either a one-stage revision or a two-stage revision THR. Blinding is not possible due to the nature of the intervention. All patients will be followed up for 18 months. The primary outcome is the WOMAC Index, which assesses hip pain, function and stiffness, collected by questionnaire at 18 months. Secondary outcomes include the following: cost-effectiveness, complications, re-infection rates, objective hip function assessment and quality of life. A nested qualitative study will explore patients' and surgeons' experiences, including their views about trial participation and randomisation. DISCUSSION: INFORM is the first ever randomised trial to compare two widely accepted surgical interventions for the treatment of PJI: one-stage and two-stage revision THR. The results of the trial will benefit patients in the future as the main focus is on patient-reported outcomes: pain, function and wellbeing in the long term. Patients state that these outcomes are more important than those that are clinically derived (such as re-infection) and have been commonly used in previous non-randomised studies. Results from the INFORM trial will also benefit clinicians and NHS managers by enabling the comparison of these key interventions in terms of patients' complication rates, health and social resource use and their overall cost-effectiveness. TRIAL REGISTRATION: Current controlled trials ISRCTN10956306 (registered on 29 January 2015); UKCRN ID 18159.

Re-infection outcomes following one- and two-stage surgical revision of infected hip prosthesis in unselected patients: protocol for a systematic review and an individual participant data meta-analysis.

BACKGROUND: Several aggregate published reviews have compared the effectiveness of one- and two-stage surgical revision to prevent re-infection following prosthetic hip infection and have reported inconsistent results. In addition, there were several features of these previous reviews which limited the validity of the findings. In the absence of a well-designed clinical trial, we propose the Global Infection Orthopaedic Management (INFORM) collaboration, a worldwide collaborative systematic review and meta-analysis of individual participant data (IPD) to address the existing uncertainties. METHODS: Cohort studies (prospective or retrospective) and randomised controlled trials conducted in unselected patients with infection treated exclusively by one- or two-stage revision and reporting re-infection outcomes within 2 years of revision will be retrieved by searching the following databases: MEDLINE, EMBASE, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials and the WHO International Clinical Trials Registry Platform. Reference lists of relevant studies will be manually scanned and there will be email contact with investigators of grey literature and conference abstracts. Investigators will be invited to join the Global INFORM collaboration and share their individual level data. The primary outcome of the analyses will be incidence of re-infection within 2 years of commencement of revision surgery. Primary analyses will be conducted comparing the one-stage to the two-stage surgical revision. IPD analyses will be based on Cox proportional hazard (PH) models estimated for each study separately. Study-specific log hazard ratios will be combined using random-effects meta-analysis with fixed-effects meta-analysis in subsidiary analyses. Hazard ratios for re-infection according to different individual level characteristics such as sex, age groups, body mass index and comorbidities will also be assessed. DISCUSSION: The analyses will enable a consistent approach to the definition of re-infection outcomes, more detailed analyses under a broader range of circumstances and exploration of potential sources of heterogeneity and produce much more valid and precise estimates of re-infection outcomes. SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2015: CRD42015016664.

High failure rates of the Spectron EF stem at a minimum of 10 year's follow-up.

We prospectively followed 112 hips, undergoing THA with a Spectron EF stem. At mean follow-up of 11.2years, 21 patients had died. We obtained radiological follow-up in 99% and clinical follow-up in 100% of the surviving 91 hips. Fifty-four percent demonstrated osteolysis in at least one Gruen zone. Twenty-two hips required revision for all causes, with a further five stems radiologically loose. With endpoint being stem revision for aseptic loosening or radiological failure, survivorship at 11years was 0.783. We believe the addition of a rougher surface finish has contributed to the high levels of osteolysis and stem failure seen with the Spectron EF.

Cemented polished tapered stems in patients less than 50 years of age: a minimum 10-year follow-up.

We report the outcome of 58 consecutive polished tapered stems in 47 patients younger than 50 years, with a minimum of 10 years of follow-up. No stems were revised for aseptic loosening or osteolysis. The Harris hip scores were good or excellent in 76% of the patients. There was excellent preservation of proximal bone. Despite higher patient weight and frequent previous surgery, the outcome of polished tapered stems in patients younger than 50 years is comparable to the general population undergoing total hip arthroplasty and superior to other non-polished tapered stem designs in young patients. Cup wear and cup failure were significantly worse in this group, with a higher incidence of periarticular osteolysis. Polished tapered stem designs are the benchmark for comparison to other arthroplasty options in young patients.

Cement burn of the skin during hip replacement.

We present the first reported case of a partial thickness burn to the skin from discarded bone cement during a routine total hip replacement (THR). The patient required plastic surgical attention for 5 months before the skin was healed. We summarise the reported incidents of cement burns to various other structures and the circumstances in which these injuries can potentially occur.