A comparison of mortality rates following revision hip arthroplasty for periprosthetic fracture, infection or aseptic loosening.

BACKGROUND: Mortality following revision hip surgery for periprosthetic fracture (PPF) is comparable to neck of femur fractures. Our institution provides a regional "PPF Service". The aim of this study was to determine the time to surgery and mortality rate for PPF, compared to revision for infection or aseptic loosening. METHODS: Revision arthroplasty procedures performed for PPF, infection or aseptic loosening between January 2014 and December 2015 were identified. Comparisons were made between the 3 groups for baseline demographics, admission to higher-level care, length of stay, complications and mortality. RESULTS: There were 37 PPF, 71 infected and 221 aseptic revisions. PPF had a higher proportion of females (65% vs. 39% in infection and 53% in aseptic; p = 0.031) and grade 3 and 4 ASA patients (p = 0.006). Median time to surgery for PPF was 8 days (95% CI, 6-16). Single-stage procedures were performed in 84% of PPF, 42% of infections and 99% of aseptic revisions (p < 0.001). 19% of PPF revisions required HDU admission, 1% in the aseptic group and none in the infection group. Median length of stay was significantly different (PPF 10; infection 14; aseptic 8 days (p < 0.001). The 1-year mortality rate for PPF was 0%, 2.8% for infection and 0.9% in the aseptic group (p = 0.342). CONCLUSIONS: Despite the PPF group having higher ASA grades and more HDU admissions, our 1-year mortality rate was 0% and not significantly different to infection or aseptic loosening. Our low complication and 1-year mortality rate is encouraging and supports the safety of a regional "Periprosthetic Fracture Service".

Early Functional Outcomes After Evolutionary Total Knee Arthroplasty: A Randomized Controlled Trial. Is New Always Better?

Total knee replacement (TKR) designs continue to evolve with the aim of improving patient outcomes; however, there remains a significant patient dissatisfaction rate. We report the early functional outcomes of an evolutionary knee design in the context of a single-blinded, noninferiority, randomized controlled trial. METHODS: Patients were randomized to receive either the P.F.C. SIGMA or ATTUNE knee implant systems (DePuy Synthes). All implants were fixed-bearing, cruciate-retaining, and cemented constructs. Patients were assessed at baseline and 6 weeks, 3 months, and 1 year postoperatively using clinical and functional outcome measures, including range of motion, Oxford Knee Score (OKS), Oxford Knee Score-Activity and Participation Questionnaire (OKS-APQ), Patient Knee Implant Performance (PKIP) score, 5-Level EuroQol 5 Dimensions (EQ-5D-5L), and Short Form-36 outcome measures. RESULTS: There were 150 patients who underwent a surgical procedure (76 with the ATTUNE implant and 74 with the P.F.C. SIGMA implant), with 147 patients remaining at the final review. No differences were observed in any of the outcome measures between the groups at any time point. Tourniquet time was significantly shorter in the P.F.C. SIGMA arm (p = 0.001); however, this had no clinical impact on the OKS (analysis of covariance [ANCOVA] test) at the final review (p = 0.825). There was no difference in the numbers of patients achieving the minimal clinically important difference for the OKS between the groups (p = 0.817). CONCLUSIONS: This trial did not show inferiority of the ATTUNE implant when compared with the P.F.C. SIGMA implant. The authors believe that implant innovation should continue and that modern implants should be introduced into the market following randomized controlled trials. Further work should assess the effect of non-implant-related factors on patient outcomes. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Is Preoperative Identification of the Infecting Organism Essential Before Single-Stage Revision Hip Arthroplasty for Periprosthetic Infection?

BACKGROUND: It is commonly stated that identification of the infecting organism is a prerequisite to single-stage revision arthroplasty of the hip for deep infection. We have performed single-stage revision in a series of patients where the organism was not identified preoperatively. The aim of this study is to investigate whether the rate of infection eradication following single-stage revision was affected by preoperative knowledge of the infecting organism. METHODS: We identified all patients who had undergone a single-stage revision for a deep infection at our hospital between 2006 and 2015. One hundred five patients were assigned into 2 groups based upon whether the infecting organism had been identified preoperatively (group A = 28) or not (group B = 77). RESULTS: The reinfection rates were 3.6% in group A and 9.1% for group B (P = .679). Re-revision rates were 7.1% and 9.1%, respectively (P = 1.00). Overall, the implant survival rate at 6 years was 87.9% (95% confidence interval, 97.4-78.4). In group B, preoperative aspiration was performed in 36.4% (28/77) of cases. Staphylococci species were the predominant causative organisms, with gram-negative involvement in 19.0% (20/105) of cases. CONCLUSION: The rate of infection eradication and overall survivorship with single-stage revision was similar in our series to that reported in the literature. While desirable, we did not find identification of the infecting organism before surgery influenced the outcome. Given the functional and economic benefits of single-stage revision, we suggest that failure to identify an organism is not an absolute contraindication to this approach.

Study to Assess the Rate of Adverse Reaction to Metal Debris in Hip Resurfacing at a Minimum 13-year Follow-up.

BACKGROUND: Hip Resurfacing (HR), although reducing in popularity, is still used in the younger male population. Excellent medium-term results have been published; however, the use of metal on metal has reduced with increased awareness of adverse reactions to metal debris (ARMD). ARMD has been shown to often be clinically "silent" following large Head MoM total hip replacement (THR). The purpose of our study was to report the incidence of ARMD following HR with a minimum follow-up of 13 years. METHODS: We performed a retrospective study of a consecutive series of patients who underwent HR between January 1, 2000 and August 1, 2005. All patients were entered into our hospital MoM hip replacement surveillance program database. Patients were reviewed yearly for symptoms and blood ion levels. Patients had Magnetic Resonance (MR) imaging to assess for ARMD. RESULTS: A total of 102 patients with 123 hip replacements were included in the study. Eight hips in 7 patients were revised: two for fracture, one for avascular necrosis, and five for ARMD. A best-case scenario of 109 (93.2%) resurfacings were surviving at 13 years. With regard to the radiological analysis, 34% were found to have ARMD on MR. CONCLUSION: While the implant survivorship in our series is acceptable, we found a high incidence of ARMD. Surgeons and patients with or considering a HR should be aware of the risk of ARMD developing. This allows an informed choice as to the best implant for their personal requirement and informs of the potential modes of failure and need for long-term screening.

Periprosthetic fractures: the next fragility fracture epidemic? A national observational study.

OBJECTIVES: Periprosthetic fractures have considerable clinical implications for patients and financial implications for healthcare systems. This study aims to determine the burden of periprosthetic fractures of the lower and upper limbs in England and identify any factors associated with differences in treatment and outcome. DESIGN: A national, observational study. SETTING: England. PARTICIPANTS: All individuals admitted to hospital with periprosthetic fractures between 1 April 2015 and 31 December 2018. PRIMARY AND SECONDARY OUTCOME MEASURES: Mortality, length of stay, change in rate of admissions. METHODS: We analysed Hospital Episode Statistics data using the International Classification of Diseases 10th Revision code M96.6 (Fracture of bone following insertion of orthopaedic implant, joint prosthesis, or bone plate) to identify periprosthetic fractures recorded between April 2013 and December 2018. We determined the demographics, procedures performed, mortality rates and discharge destinations. Patient characteristics associated with having a procedure during the index admission were estimated using logistic regression. The annual rate of increase in admissions was estimated using Poisson regression. RESULTS: Between 1 April 2015 and 31 December 2018, there were 13 565 patients who had 18 888 admissions (89.5% emergency) with M96.6 in the primary diagnosis field. There was a 13% year-on-year increase in admissions for periprosthetic fracture in England during that period. Older people, people living in deprived areas and those with heart failure or neurological disorders were less likely to receive an operation. 14.4% of patients did not return home after hospital discharge. The overall inpatient mortality was 4.3% and total 30-day mortality was 3.3%. CONCLUSIONS: The clinical and operational burden of periprosthetic fractures is considerable and increasing rapidly. We suggest that the management of people with periprosthetic fractures should be undertaken and funded in a similar manner to that successfully employed for people sustaining hip fractures, using national standards and data collection to monitor and improve performance.

Custom triflange revision acetabular components for significant bone defects and pelvic discontinuity: Early UK experience.

AIMS: We report our early experience in acetabular reconstruction for significant bone loss and pelvic discontinuity using custom triflange acetabular components. PATIENTS AND METHODS: Retrospective consecutive review of all patients treated at our specialist tertiary unit with significant acetabular defects (Paprosky 3A/3B) and pelvic discontinuity who were reconstructed with custom triflange implants. The primary outcomes were radiographic failure and complications. RESULTS: 17 patients (17 hips) were included; 3 males/14 females with a mean age of 72 years (range 61-83). The average follow-up was 3.6 years (2-7 years). Bony defects were Paprosky 3B in 13/17 hips (76%) with pelvic discontinuity encountered in the majority of cases 15/17 hips (88%) and intra-pelvic failed components in 11/17 (64%). At final follow up, no radiographic failures were observed although three patients developed complications (17.6%); haematoma requiring washout out; intra-operative ilium fracture; and recurrent dislocation in one patient. CONCLUSIONS: Our experience suggest that acceptable outcomes can be achieved with custom implants for this group of challenging patients, although longer follow up is needed to monitor future implants' failure.

Preoperative pain catastrophisation may predict worse patient-reported outcomes after primary hip arthroplasty: A pilot study.

AIM: to investigate the relationship between pain catastrophising and patient-reported clinical outcomes following primary total hip arthroplasty. MATERIALS AND METHODS: prospective consecutive study of 103 patients who completed preoperative Pain Catastrophisation Score (PCS), preoperative and 12-month postoperative Oxford Hip Score (OHS). Correlation analysis was carried out between the improvement in OHS (mean difference between pre- and postoperative scores) and the mean preoperative PCS score using the Pearson's r rank test. Multiple linear regression was then performed using the postoperative OHS as the outcome variable against a number of predictor variables. RESULTS: there were 37 males and 66 females with average age of 60.5 years (range 22-84). Mean preoperative PCS score was 16.3 (±13.6; range 0-49). Mean preoperative OHS was 16.5 (±3.5) which had improved at 12-months postoperatively to a mean 38.1 (±11.1). The difference was statistically significant (P < 0.0001). Preoperative PCS scores were correlated with the OHS improvement at 12-months which revealed a weak negative correlation Pearson's correlation coefficient r = - 0.248 (P = 0.0114). Preoperative PCS score, predictor variable, had statistically significant relationship with the postoperative OHS (P = 0.0207). The regression coefficient for the PCS was -0.25, therefore for each unit increase in the preoperative PCS score there was a 0.25 unit decrease in the postoperative OHS score. CONCLUSION: pain catastrophising appear to predict poorer postoperative patient-reported outcome measures. Further research is needed to evaluate the value of early identification of high-risk patients and the role of preoperative involvement of pain specialists and its effects on postoperative outcomes.

Wear rate and medium-term survival of a cemented, moderately cross-linked polyethylene acetabular prosthesis.

INTRODUCTION: The moderately cross-linked Depuy Marathon® cemented acetabular component was introduced into the UK in 2007. The wear rate for the previously introduced Marathon® uncemented acetabular component has been reported to range from 0.06 to 0.01 mm/year. The aim of this study was to present the medium-term results and wear rate of the Marathon® cemented prosthesis used in primary total hip arthroplasty. METHODS: 103 Marathon® cemented acetabular components were implanted between 2008 and 2009 in primary arthroplasty, who were eligible for this study. All patients received a metal 28-mm head. Mean age was 68 years (range 27-87). Mean clinical follow-up was 55 months (range 50-61). Mean radiological follow-up was 46 months (range 24-57). Wear was calculated on AP radiographs using computer-assisted uni-radiographic technique. RESULTS: The mean wear was 0.37 mm (range 0.0-0.78 mm). The wear rate was calculated as 0.03 mm/year (95% confidence interval 0.02-0.06). Postoperative complications included deep vein thrombosis (2%) and dislocation (0.8%); there were no deep infections. There were no revisions for failure of the Marathon® cemented acetabular component. CONCLUSIONS: The Marathon® cemented acetabular component demonstrates satisfactory wear rates and survivorship at medium-term follow-up.

Complications of total hip arthroplasty: periprosthetic fractures of the acetabulum.

Periprosthetic fractures of the acetabulum are a rare but potentially disastrous complication of total hip arthroplasty. Such fractures occur either as early perioperative complications or late complications when they are associated with either significant trauma or as a result of the loss of the structural integrity of the bone supporting the prosthesis, such as aseptic osteolysis. The incidence of such fractures appears to be increasing with the increased use of uncemented acetabular components. This article explores the current literature on the epidemiology, etiology, and classification of periprosthetic acetabular fractures as well as offering potential treatment strategies.

Long stem cemented revision arthroplasty for aseptic loosening in elderly patients produces good results, despite significant bone loss.

We assessed the results of long cemented stems in patients over 65 undergoing a first time revision hip arthroplasty for aseptic loosening. 103 patients were followed up for a minimum of five years after revision surgery; 45% had EndoKlinik C grade preoperative bone loss. At final follow-up 31 patients had died, all but one with the prosthesis in situ. There were 71 revisions alive, one had been revised for a peri-prosthetic fracture. Of the 45 that had radiographs at a minimum of five years, three stems were probably or definitely loose according to the Harris classification. There was 92% patient satisfaction and a mean Oxford Hip Score (OHS) of 25/60 in the 59 patients that had not been revised and had full clinical follow-up. Long-stem cemented revisions for aseptic loosening in elderly patients allow immediate postoperative weight bearing and have good radiological and clinical outcomes.

Metal ion levels not sufficient as a screening measure for adverse reactions in metal-on-metal hip arthroplasties.

This study aims to assess the accuracy of metal ion analysis in the diagnosis of adverse reaction to metal debris (ARMD) in patients with metal-on-metal hip arthroplasties by comparing the cobalt and chromium levels in 57 patients (62 hips) to findings on metal artifact reduction magnetic resonance imaging (MRI). An ARMD was detected using MRI in 18 (29%) of the hips. Forty patients had cobalt levels less than 7 µg/L, and 33 had chromium levels less than 7 µg/L, but 8 of these had an ARMD on MRI and only minimal symptoms (Oxford Hip Score ≥ 44/48). The incidence of ARMD was significantly higher when chromium concentration was above 7 µg/L (P = .02), but normal metal ion levels can be misleading and metal artifact reduction MRI imaging is advised in all patients.

Revision of medial Oxford unicompartmental knee replacement to a total knee replacement: similar to a primary?

Unicompartmental knee replacement (UKR) is an option for the treatment of isolated medial compartment osteoarthritis. A commonly perceived potential advantage is that revision of a UKR is straightforward. The purpose of this study was to determine the early outcomes and the level of complexity of revisions of Oxford UKRs performed at our hospital. A retrospective review of a prospective database of all phase III Oxford UKRs was undertaken. This identified 89 Oxford UKRs which were revised at our institution between 2002 and 2008. The median time from the primary procedure to revision was 19 months (interquartile range 2-73 months). Nine were revised to another UKR. Eighty were revised to a total knee replacement (TKR). Fifty-three were revised with primary TKR components. Twenty-seven were revised using stems and/or augments. The median overall tibial component thickness (including augments) was 15 mm. Forty-five knees had an overall tibial component thickness greater than 15 mm. A primary Oxford UKR bearing thickness of greater than 6mm was associated with an increased likelihood of requiring revision components. On the basis of this review, tibial bone defects were commonly encountered when revising UKRs. Reconstruction with either an augment and a stem, or thick polyethylene component was often required. We recommend that the potential complexity of revision for UKR failure should be borne in mind when considering a primary Oxford UKR.

Silent soft tissue pathology is common with a modern metal-on-metal hip arthroplasty.

BACKGROUND AND PURPOSE: Adverse reactions to metal debris have been reported to be a cause of pain in metal-on-metal hip arthroplasty. We assessed the incidence of both symptomatic and asymptomatic adverse reactions in a consecutive series of patients with a modern large-head metal-on-metal hip arthroplasty. METHODS: We studied the early clinical results and results of routine metal artifact-reduction MRI screening in a series of 79 large-head metal-on-metal hip arthroplasties (ASR; DePuy, Leeds, UK) in 68 patients. 75 hips were MRI scanned at mean 31 (12-52) months after surgery. RESULTS: 27 of 75 hips had MRI-detected metal debris-related abnormalities, of which 5 were mild, 18 moderate, and 4 severe. 8 of these hips have been revised, 6 of which were revised for an adverse reaction to metal debris, diagnosed preoperatively with MRI and confirmed histologically. The mean Oxford hip score (OHS) for the whole cohort was 21. It was mean 23 for patients with no MRI-based evidence of adverse reactions and 19 for those with adverse reactions detected by MRI. 6 of 12 patients with a best possible OHS of 12 had MRI-based evidence of an adverse reaction. INTERPRETATION: We have found a high early revision rate with a modern, large-head metal-on-metal hip arthroplasty. MRI-detected adverse rections to metal debris was common and often clinically "silent". We recommend that patients with this implant should be closely followed up and undergo routine metal artifact-reduction MRI screening.

Fluid temperatures during arthroscopic subacromial decompression using a radiofrequency probe.

Our aim was to investigate the temperatures reached in the subacromial space during radiofrequency ablation of the subacromial bursa, in order to see if the probes generate sufficiently high temperatures to cause chondrolysis of the articular surfaces in the glenohumeral joint. We recorded the maximum temperatures in the subacromial space during arthroscopic subacromial decompression on 30 consecutive patients using a sterile digital temperature probe (Series 400, DeRoyal, TN, USA). Both the mean (27.8 degrees C) and maximum (41.8 degrees C) temperatures reached were below the experimental thresholds for chondrocyte damage. At 2 year follow-up we report no cases of chondrolysis or other complications related to the radiofrequency probes and conclude that given the relatively low maximum temperatures generated by the probes the risk of adverse effects is minimal.

Outcome of traumatic subtrochanteric femoral fractures fixed using cephalo-medullary nails.

We performed a retrospective review of 101 patients sustaining 102 traumatic, non-pathological subtrochanteric fractures treated with cephalo-medullary nailing over a period of 6 years from 1999 to 2005. Mean follow up was 24 weeks (range: 6-96). Twenty patients were lost to follow up and 21 died, whilst 57 of 60 fractures were followed to union. There were 19 fractures fixed in varus, as defined as a varus angulation of greater than 10 degrees at the fracture site. Implant failure, 9 of the 10 malunions and all 3 of the non-unions occurred in the varus group whilst only 1 malunion occurred in the satisfactory reduction group. This difference in outcome is statistically significant (p<0.0001). Twenty four of the 60 patients had undergone open reduction at the time of fixation. There were three malunions and one non-union in the open reduction group compared with six and two, respectively in the closed group (p>0.05). Post-operative recovery rates, infection rates and other complications were similar for both groups. We therefore advocate the use of open reduction where necessary to avoid varus malreduction to avoid such complications, particularly as open reduction was not associated with a higher complication rate in this series. The study supports the use of cephalo-medullary nailing for subtrochanteric fractures with a union rate of 95%.