Andrew P. Sprowson

Blood metal ion concentrations after hip resurfacing arthroplasty: A COMPARATIVE STUDY OF ARTICULAR SURFACE REPLACEMENT AND BIRMINGHAM HIP RESURFACING ARTHROPLASTIES

There have been no large comparative studies of the blood levels of metal ions after implantation of commercially available hip resurfacing devices which have taken into account the effects of femoral size and inclination and anteversion of the acetabular component. We present the results in 90 patients with unilateral articular surface replacement (ASR) hip resurfacings (mean time to blood sampling 26 months) and 70 patients with unilateral Birmingham Hip Resurfacing (BHR) implants (mean time 47 months). The whole blood and serum chromium (Cr) and cobalt (Co) concentrations were inversely related to the size of the femoral component in both groups (p < 0.05). Cr and Co were more strongly influenced by the position of the acetabular component in the case of the ASR, with an increase in metal ions observed at inclinations > 45 degrees and anteversion angles of < 10 degrees and > 20 degrees. These levels were only increased in the BHR group when the acetabular component was implanted with an inclination > 55 degrees. A significant relationship was identified between the anteversion of the BHR acetabular component and the levels of Cr and Co (p < 0.05 for Co), with an increase observed at anteversion angles < 10 degrees and > 20 degrees. The median whole blood and serum Cr concentrations of the male ASR patients were significantly lower than those of the BHR men (p < 0.001). This indicates that reduced diametral clearance may equate to a reduction in metal ion concentrations in larger joints with satisfactory orientation of the acetabular component.

A systematic review of the evidence for single stage and two stage revision of infected knee replacement

BackgroundPeriprosthetic infection about the knee is a devastating complication that may affect between 1% and 5% of knee replacement. With over 79 000 knee replacements being implanted each year in the UK, periprosthetic infection (PJI) is set to become an important burden of disease and cost to the healthcare economy. One of the important controversies in treatment of PJI is whether a single stage revision operation is superior to a two-stage procedure. This study sought to systematically evaluate the published evidence to determine which technique had lowest reinfection rates.MethodsA systematic review of the literature was undertaken using the MEDLINE and EMBASE databases with the aim to identify existing studies that present the outcomes of each surgical technique. Reinfection rate was the primary outcome measure. Studies of specific subsets of patients such as resistant organisms were excluded.Results63 studies were identified that met the inclusion criteria. The majority of which (58) were reports of two-stage revision. Reinfection rated varied between 0% and 41% in two-stage studies, and 0% and 11% in single stage studies. No clinical trials were identified and the majority of studies were observational studies.ConclusionsEvidence for both one-stage and two-stage revision is largely of low quality. The evidence basis for two-stage revision is significantly larger, and further work into direct comparison between the two techniques should be undertaken as a priority.

ASARM-truncated MEPE and AC-100 enhance osteogenesis by promoting osteoprogenitor adhesion

Matrix extracellular phosphoglycoprotein (MEPE) is a member of the SIBLING (Small Integrin‐Binding Ligand, N‐linked Glycoprotein) family of secreted glycophosphoproteins. Several previous studies have demonstrated that MEPE and its peptide motif, AC‐100, may regulate bone mass and influence osteoblast activity, suggesting its potential for inclusion in novel therapeutic strategies aimed at increasing osteogenesis. Our study uses in vitro approaches to assess how adhesion of nonadherent cells is influenced by MEPE and whether response to MEPE is dependent on the maturity of osteoblastic cells. Truncated MEPE (ASARM removed) or AC‐100 enhanced the adhesion, spreading, and focal complex formation of unadhered osteoblastic cells leading to increased differentiation and bone formation after 28 days of culture. Furthermore, addition of truncated MEPE or AC‐100 to mature osteoblasts had no significant effect on bone formation. Our data supports an action for truncated MEPE and AC‐100 in altering the physiology of immature poorly adherent cells which subsequently influences the way in which these cells interact with a substrate to facilitate their survival and/or commitment to the osteoblast lineage.

Systematic review of microendoscopic discectomy for lumbar disc herniation

Study designSystematic review.ObjectiveTo search and analyse randomised controlled trials (RCTs) published since the Cochrane review by Gibson and Waddell (2007) comparing microendoscopic discectomy (MED) with open discectomy (OD) or microdiscectomy (MD) and to assess whether MED improves patient-reported outcomes.Summary of backgroundDiscectomy for symptomatic herniated lumbar discs is an effective operative treatment. A number of operative techniques exist including OD, MD, and MED. A 2007 Cochrane review identified OD as an effective treatment for symptom improvement, and found sufficient evidence for MD. However, evidence for MED was lacking.MethodsA systematic review of Medline and Embase was carried out. Aiming to identify RCTs carried out after 2007, which compared OD with MD and MED which reported the Oswestry disability index (ODI) as an outcome.ResultsFour RCTs were identified. None of the studies found a significant difference in the ODI scores between study groups at any time point. Three studies compared MED to OD and one compared OD, MD, and MED. The largest study reported an increased number of severe complications in the MED group.ConclusionsThere is some evidence to suggest that MED performed by surgeons skilled in the technique in tertiary referral centres is as effective as OD.

Enhanced education and physiotherapy before knee replacement; is it worth it? A systematic review.

BACKGROUND Around 20% of knee replacement have an unsatisfactory outcome. Pre-operative physiotherapy and education have been proposed to improve post-operative outcomes. OBJECTIVES This systematic review evaluated whether these factors improved length of stay and patient reported outcomes after knee replacement surgery. DATA SOURCES Medline, Embase, CINAHL, Cochrane Central Register of Controlled Trials, PsycINFO and PEDro were searched on the 1st January 2013. STUDY SELECTION OR ELIGIBILITY CRITERIA Randomised or quasi-randomised studies assessing either pre-operative education or physiotherapy on patients undergoing a planned total or partial knee replacement were included in the review. Only studies with a control group receiving a defined standard of pre-operative care were included. RESULTS Eleven studies met the inclusion criteria set. Two studies analysed the effect of pre-operative education, seven pre-operative treatment by a physiotherapist and two studies used both factors. No study found significant differences in validated joint specific patient reported outcome measures. The education studies found a decrease in pre-operative expectation and an improvement in knowledge, flexion and regularity of exercise. Two studies found an improvement in muscle strength in the group treated by a physiotherapist at three months. The combination of education and physiotherapy was shown to reduce patient length of stay and cost in one study. CONCLUSION The evidence reviewed is insufficient to support the implementation of either pre-operative education or physiotherapy programmes. The combination of pre-operative education and treatment by a physiotherapist may reduce the medical costs associated with surgery.

Impact factors of orthopaedic journals between 2000 and 2010: trends and comparisons with other surgical specialties

PurposeThe impact factors (IF) of orthopaedic journals is an important component in determining the future of orthopaedic research funding. We aim to characterise the trend in journal IF over the last decade and draw comparisons with other surgical specialties.MethodsWe conducted an analysis of impact factors from Journal Citation Reports between 2000 and 2010.ResultsBetween 2000 and 2010 the number of orthopaedic journals increased from 24 to 41, more than any other surgical specialty and the mean IF increased from 0.842 to 1.400. Journals printed in the English language had a significantly higher IF in the year 2010 (1.64 vs. 0.33, p = 0.01) than those printed in other languages. English language journals published in the US had significantly higher mean 2010 IF (1.932 vs. 1.243, p = 0.025) than those published in Europe, and this had changed compared with 2000 mean IF (0.978 Vs. 0.704, p = 0.360). Orthopaedics was ranked sixth out of 11 surgical subspecialties in 2000 but dropped to seventh out of 11 in 2010.ConclusionsThe quality of orthopaedic journals has significantly increased over the last decade and this has been accompanied by a rise in mean IF. It is important that orthopaedics continues to improve the quality of research, which may help orthopaedic researchers secure funding in the future.

Management of degenerative meniscal tears and the role of surgery

#### The bottom line #### How patients were involved in the creation of this article Eight patients (four each from the UK and Australia) read the manuscript and provided comments. They made some suggestions for improving clarity in the advice for patients box, which we have incorporated. The use of knee arthroscopy to treat degenerative meniscal tears is well established worldwide. However, with the advent of high quality randomised controlled trials questioning its value, observations that these lesions are usually asymptomatic, and recognition that arthroscopy is a “difficult habit to break,”1 it is timely to review the best evidence based management of these tears and reconsider the role of surgery. The menisci are two largely aneural crescent shaped discs of fibrocartilage, which sit within the lateral and medial compartments of the knee joint. They evenly transfer load across the joint, absorb shock during dynamic movement, and lubricate and help stabilise the joint. Injury, degeneration, or surgical removal of all or part of the meniscus is associated with an increased risk of developing knee osteoarthritis.2 The risk of osteoarthritis and its progression increase in line with reductions in tibial cartilage coverage. Meniscal tears are categorised as traumatic or non-traumatic (degenerative) on the basis of their presentation. Traumatic tears tend to occur in younger active people (<40 years) and are caused by a serious traumatic injury, often while playing sport. Degenerative tears …

Prophylactic antibiotics in elective hip and knee arthroplasty: an analysis of organisms reported to cause infections and national survey of clinical practice

Objectives We wanted to investigate regional variations in the organisms reported to be causing peri-prosthetic infections and to report on prophylaxis regimens currently in use across England. Methods Analysis of data routinely collected by Public Health England’s (PHE) national surgical site infection database on elective primary hip and knee arthroplasty procedures between April 2010 and March 2013 to investigate regional variations in causative organisms. A separate national survey of 145 hospital Trusts (groups of hospitals under local management) in England routinely performing primary hip and/or knee arthroplasty was carried out by standard email questionnaire. Results Analysis of 189 858 elective primary hip and knee arthroplasty procedures and 1116 surgical site infections found statistically significant variations for some causative organism between regions. There was a 100% response rate to the prophylaxis questionnaire that showed substantial variation between individual trust guidelines. A number of regimens currently in use are inconsistent with the best available evidence. Conclusions The approach towards antibiotic prophylaxis in elective arthroplasty nationwide reveals substantial variation without clear justification. Only seven causative organisms are responsible for 89% of infections affecting primary hip and knee arthroplasty, which cannot justify such widespread variation between prophylactic antibiotic policies. Cite this article: Bone Joint Res 2015;4:181–189.

Outcome Domains and Measures in Total Joint Replacement Clinical Trials: Can We Harmonize Them? An OMERACT Collaborative Initiative

Objective. To develop a plan for harmonizing outcomes for people undergoing total joint replacement (TJR), to achieve consensus regarding TJR outcome research. Methods. The TJR working group met during the 2014 Outcome Measures in Rheumatology (OMERACT) 12 meeting in Budapest, Hungary. Multiple conference calls preceded the face-to-face meeting. Brief presentations were made during a 1.5-h meeting, which included an overview of published systematic reviews of TJR trials and the results of a recent systematic review of TJR clinical trial outcome domains and measures. This was followed by discussion of potential core set areas/domains for TJR clinical trials (as per OMERACT Filter 2.0) as well as the challenges associated with the measurement of these domains. Results. Working group participants discussed which TJR clinical trial outcome domains/areas map to the inner versus outer core for core domain set. Several challenges were identified with TJR outcomes including how to best measure function after TJR, elucidating the source of the pre- and post-TJR joint pain being measured, joint-specific versus generic quality of life instruments and the importance of patient satisfaction and revision surgery as outcomes. A preliminary core domain set for TJR clinical trials was proposed and included pain, function, patient satisfaction, revision, adverse events, and death. This core domain set will be further vetted with a broader audience. Conclusion. An international effort with active collaboration with the orthopedic community to standardize key outcome domains and measures is under way with the TJR working group. This effort will be further developed with new collaborations.

Bio-interference screw cyst formation in anterior cruciate ligament reconstruction—10-year follow up

PURPOSE This study used serial MRI to assess the absorption of a poly l-lactide Bioabsorbable interference screw used in the anterior cruciate ligament reconstruction with a 4-strand hamstring technique. METHODS A consecutive series of ten patients undergoing anterior cruciate ligament reconstruction a 4-strand hamstring technique were assessed with magnetic resonance imaging (MRI) scans at 1, 2, 4, 7 and 10 years postoperatively. RESULTS No resorption had occurred after 4 years in any of the patients. By 7 years screw absorption was complete in seven patients and had progressed in three. New cyst formation occurred in 3 patients between 5 and 7 years. Half the patients displayed small fluid collections within the tibial tunnels. At 10 years all screws were fully absorbed; however cyst formation was common, including the development of a new cyst in the period between 7 and 10 years in one patient. None of the patients had instability, persistent effusions, or clinically detectable adverse reactions to the screws. CONCLUSIONS This study has shown that poly l-lactide bioabsorbable screws take longer to resorb than initial in vitro data suggested. It is unclear whether ganglion formation within the tibial tunnel is related to screw resorption or the hamstring graft. The theoretical advantages of bioabsorbable screws must be weighed against these findings.