Background

Post-traumatic immunosuppression (PTI) after surgery increases vulnerability to nosocomial infections, sepsis, and death. Knee arthroplasty offers a sterile clinical model to characterise PTI and explore its underlying mechanisms.

Background

Recent studies have suggested that full-limb radiographs are more accurate and sensitive than short film radiographs for pre-operative measurement of the anatomical angles required to achieve optimal knee alignment in Total Knee Arthroplasty (TKA). However, there are drawbacks associated with their use including excess radiation to the pelvic organs, the need for specialised radiography equipment and increased cost. Given these drawbacks, we compared the use of MRI scans, a commonly performed pre-operative investigation, with short film knee radiographs for measurement of knee alignment.

Background

Over 96% of primary total hip replacements (THR) recorded in the National Joint Registry (NJR) are performed through a posterior or lateral surgical approach. There is no high quality evidence available to support the use of one approach over the other in primary THR and even less evidence when the outcome of revision THR is considered.

Background

Dissociation of the polyethylene liner is a known failure mechanism of the Harris Galante I and II uncemented acetabular components. The outcomes of revision surgery for this indication and the influence of time to diagnosis are not well described.

Background

The two-stage revision strategy has been claimed as being the “gold standard” for treating prosthetic joint infection. The one-stage revision strategy remains an attractive alternative option, however, its effectiveness in comparison to the two-stage strategy remains uncertain. A systematic review and meta-analysis was conducted to compare the effectiveness of one- and two-stage revision strategies to prevent re-infection after prosthetic hip infection.

Joint arthroplasty is a common surgical procedure, with over 185,000 primary hip and knee arthroplasties performed in England, Wales and Northern Ireland in 2014. After total hip or knee arthroplasty, about 1% of patients develop deep prosthetic joint infection (PJI), which usually requires further major operations to clear the infection. Although PJI affects only a small percentage of patients it is one of the most devastating complications associated with this procedure. Research evidence has focussed on clinical effectiveness of revision surgery while there has been less focus on the impact on patients and support needs. Using a systematic review approach, the aim of this study was to assess support needs and evaluate what interventions are routinely offered to support patients undergoing treatment for PJI following hip or knee arthroplasty.

We systematically searched MEDLINE, Embase, Web of Science, PsycINFO, Cinahl, Social Science Citation Index, and The Cochrane Library from 1980 to February 15, 2015 for observational (prospective cohort, nested case-control, case-control, and retrospective cohort) studies, qualitative studies, and clinical trials that report on the support needs and interventions for patients being treated for PJI or other major adverse occurrences following joint arthroplasty. Data were extracted by two independent investigators and consensus reached with involvement of a third.

Of 4,161 potentially relevant citations, we identified one case-control, one prospective cohort and two qualitative studies for inclusion in the synthesis. Patients report that PJI and treatment had a profoundly negative impact affecting physical, emotional, social and economic aspects of their lives. No study evaluated support interventions for PJI or other major adverse occurrences following hip and knee arthroplasty.

The interpretation of study results is limited by variation in study design, outcome measures and the small number of relevant eligible studies. Findings show that patients undergoing treatment for PJI have extensive physical, psychological, social and economic support needs. Our review highlights a lack of evidence about support strategies for patients undergoing treatment for PJI and other adverse occurrences. There is a need to design, implement and evaluate interventions to support these patients.

Prosthetic joint infection (PJI) is an uncommon but serious complication of hip and knee replacement. We investigated the rates of revision surgery for the treatment of PJI following primary and revision hip and knee replacement, explored time trends, and estimated the overall surgical burden created by PJI.

We analysed the National Joint Registry for England and Wales for revision hip and knee replacements performed for a diagnosis of PJI and their index procedures from 2003–2014. The index hip replacements consisted of 623,253 primary and 63,222 aseptic revision hip replacements with 7,642 revisions subsequently performed for PJI; for knee replacements the figures were 679,010 primary and 33,920 aseptic revision knee replacements with 8,031 revisions subsequently performed for PJI. Cumulative incidence functions, prevalence rates and the burden of PJI in terms of total procedures performed as a result of PJI were calculated.

Revision rates for PJI equated to 43 out of every 10,000 primary hip replacements (2,705/623,253), i.e. 0.43%(95%CI 0.42–0.45), subsequently being revised due to PJI. Around 158 out of every 10,000 aseptic revision hip replacements performed were subsequently revised for PJI (997/63,222), i.e. 1.58%(1.48–1.67). For knees, the respective rates were 0.54%(0.52–0.56) for primary replacements, i.e. 54 out of every 10,000 primary replacements performed (3,659/679,010) and 2.11%(1.96–2.23) for aseptic revision replacements, i.e. 211 out of every 10,000 aseptic revision replacements performed (717/33,920). Between 2005 and 2013, the risk of revision for PJI in the 3 months following primary hip replacement rose by 2.29 fold (1.28–4.08) and after aseptic revision by 3.00 fold (1.06–8.51); for knees, it rose by 2.46 fold (1.15–5.25) after primary replacement and 7.47 fold (1.00–56.12) after aseptic revision. The rates of revision for PJI performed at any time beyond 3 months from the index surgery remained stable or decreased over time.

From a patient perspective, after accounting for the competing risk of revision for an aseptic indication and death, the 10-year cumulative incidence of revision hip replacement for PJI was 0.62%(95%CI 0.59–0.65) following primary and 2.25%(2.08–2.43) following aseptic revision; for knees, the figures were 0.75%(0.72–0.78) following primary replacement and 3.13%(2.81–3.49) following aseptic revision.

At a health service level, the absolute number of procedures performed as a consequence of hip PJI increased from 387 in 2005 to 1,013 in 2014, i.e. a relative increase of 2.6 fold. While 70% of those revisions were two-stage, the use of single stage revision increased from 17.6% in 2005 to 38.5% in 2014. For knees, the burden of PJI increased by 2.8 fold between 2005 and 2014. Overall, 74% of revisions were two-stage with an increase in use of single stage from 10.0% in 2005 to 29.0% in 2014.

Although the risk of revision due to PJI following hip or knee replacement is low, it is rising. Given the burden and costs associated with performing revision joint replacement for prosthetic joint infection and the predicted increased incidence of both primary and revision hip replacement, this has substantial implications for service delivery.

Patients report similar or better pain and function before revision hip arthroplasty than before primary arthroplasty but poorer outcomes after revision surgery. The trajectory of post-operative recovery during the first 12 months and any differences by type of surgery have received little attention. We explored the trajectories of change in pain and function after revision hip arthroplasty to 12-months post-operatively and compared them with those observed after primary hip arthroplasty.

We conducted a single-centre UK cohort study of patients undergoing primary (n = 80) or revision (n = 43) hip arthroplasty. WOMAC pain and function scores and 20-metres walking time were collected pre-operatively, at 3 and 12-months post-operatively. Multilevel regression models were used to chart and compare the trajectories of post-operative change (0–3 months and 3–12 months) between the types of surgery.

Patients undergoing primary arthroplasty had a total hip replacement (n=74) or hip resurfacing (n=6). Osteoarthritis was the indication for surgery in 92% of primary cases. Patients undergoing revision arthroplasty had revision of a total hip arthroplasty (n=37), hemiarthroplasty (n=2) or hip resurfacing (n=4). The most common indication for revision arthroplasty was aseptic loosening (n=29); the remaining indications were pain (n=4), aseptic lymphocyte-dominated vasculitis-associated lesion (n=4) or other reasons (n=6). Primary (87%) and revision arthroplasties (98%) were mostly commonly performed via a posterior surgical approach.

The improvements in pain and function following revision arthroplasty occurred within the first 3-months following operation (WOMAC-pain, p<0.0001; WOMAC-function, p<0.0001; timed 20-metres walk, p<0.0001) with no evidence of further change beyond this initial period (p>0.05)

While the pattern of recovery after revision arthroplasty was similar to that observed after primary arthroplasty, improvements in the first 3-months were smaller after revision compared to primary arthroplasty (p<0.0001). Patients listed for revision surgery reported lower pre-operative pain levels (p=0.03) but similar post-operative levels (p=0.268) compared to those undergoing primary surgery. At 12-months post-operation patients who underwent a revision arthroplasty had not reached the same level of function achieved by those who underwent primary arthroplasty (WOMAC-function p=0.015; Time walk p=0.004).

Patients undergoing revision hip arthroplasty should be informed that the majority of their improvement will occur in the first 3-months following surgery and that the expected improvement will be less marked than that experienced following primary surgery. More research is now required to 1.) identify whether specific in-patient and post-discharge rehabilitation tailored towards patients undergoing revision arthroplasty would improve or achieve equivalent outcomes to primary surgery and 2.) whether patients who are achieving limited improvements at 3-months post-operative would benefit from more intensive rehabilitation. This will become all the more important with the increasing volume of revision surgery and the high expectations of patients who aspire to a disease-free and active life.

Around 1% of the 185,000 primary hip and knee arthroplasties performed in the UK are followed by prosthetic joint infection (PJI). Although PJI affects a small percentage of patients, it is one of the most devastating complications associated with this procedure. Treatment usually involves further major surgery which can adversely affect patients' quality of life. Understanding current service provision provides valuable information needed to design and evaluate support interventions for patients. The aim of this survey was to identify usual care pathways and support in UK NHS orthopaedic centres for this population.

The 20 highestvolume UK NHS orthopaedic centresfor hip and knee arthroplasty account for 33–50% of all cases treated for prosthetic joint infection. Infection leads at each centre were invited to participate in a survey about usual care provision and support for PJI. Questions exploredfollow up time-points; use of standard outcome measures; multidisciplinary care plans; supportive in-patient care and care after treatment; and onward referrals. Survey responses were recorded on a standardised proforma. Data were entered into Excel for analysis, then reviewed and coded into categories and frequency statistics to describe categorical data. A descriptive summary was developed based on these categories.

Eleven of the highestvolume orthopaedic centres completed the survey. Follow-up of patients varied greatly across centres; some centres reviewed patients at weekly or 2 week intervals, while all centres saw patients at 6 weeks. Long-term follow-up varied across centres from 3–4 monthsto 12 monthly. Length of follow-up period varied from until the infection had cleared toindefinitely. Follow-up timepoints were only standardised in 4 out of 11 centres. Only 1 centre had a dedicated infection clinic. Advice on who patients should contact if they had concerns included the consultant, community nurse, extended scope practitioner or the ward, while 3 centres told patients to avoid calling their GP. Only half of the centres routinely used standardised outcome measures with patients with PJI. The majority of centres provided standard physiotherapy and occupational therapy (OT) to in-patients while approximately half also offered social support. Only one centre provided dedicated physiotherapy and OT on a separate infection ward. Three centres provided hospital at home or community services to patients in-between operative stages. Only 3 out of 11 centres stated they had specific multidisciplinary care plans in place for patients. Once discharged most patients were provided with physiotherapy, OT and social services if needed. Common barriersto referral included complexities of referring patients outside the hospital catchment area;lack of availability of community services, and shortage of staff including physiotherapists. Delays in rehab and social services could also be problematic.

Findings show wide variation intreatment pathways and support for patients treated for PJI, both as inpatients and in the community. Only one of the 11 centreswho participated had a dedicated infection clinic. Only one centre suggested they individualised their physiotherapy support. A number of barriers exist to referring patients on to other support services after revision surgery.

Around 1% of total hip replacements are follow by prosthetic joint infection (PJI). There is uncertainty about best treatment method for PJI, and the most recent high quality systematic reviews in unselected patients indicates that re-infection rates following one-stage and two-stage revision arthroplasty are relatively similar. In the absence of evidence randomised controlled trials will help to identify the most clinically and cost-effective treatment for PJI. Before such trials are conducted, there is a need to establish reasons for current practice and to identify whether trials are feasible. This study aimed to deliver research that would inform trial design. Specifically, we aimed to characterise consultant orthopaedic surgeons' decisions about performing either one-stage or two-stage exchange arthroplasty for patients with PJI after hip replacement and to identify whether a randomised trial comparing one-stage with two-stage revision would be possible.

Semi-structured interviews were conducted with 12 consultant surgeons from 5 high-volume National Health Service (NHS) orthopaedic departments in the UK. Surgeons were sampled on the basis that they perform revision surgery for PJI after hip arthroplasty and final sample size was justified on the basis of thematic saturation. Surgeons were interviewed face-to-face (n=2) or via telephone (n=10). The interview study took place before design of a multicentre prospective randomised controlled trial comparing patient and clinical outcomes after one-stage or two-stage revision arthroplasty. Data were audio-recorded, transcribed, anonymised and analysed using a thematic approach, with 25% of transcripts independently double-coded.

Results: There is no standard surgical response to the treatment of PJI and surgeons manage a complex balance of factors when choosing a surgical strategy. These include multiple patient-related factors, their own knowledge and expertise, available infrastructure and the infecting organism. Surgeons questioned whether evidence supports the emergence of two-stage revision as a method. They described the use of loosely cemented articulating spacers as a way of managing uncertainty about best treatment method. All surgeons were supportive of a randomised trial to compare one-stage and two-stage revision surgery for PJI after hip replacement. Surgeons reported that they would put patients forward for randomisation when there was uncertainty about best treatment.

Surgeons highlighted the need for evidence to support their choice of revision. Some surgeons now use revision methods that can better address both clinical outcomes and patients' quality of life, such as loosely cemented articulating spacers. Surgeons thought that a randomised controlled trial comparing one-stage and two-stage exchange joint replacement is needed and that randomisation would be feasible. The next stage of the work was to design a multi-centre randomised controlled trial, this has been achieved and the trial is now ongoing in the UK.

Femoral head collapse due to avascular necrosis (AVN) is a relatively rare occurrence following intertrochanteric fractures; however, with over thirty-thousand intertrochanteric fractures per year in England and Wales alone, and an incidence of up to 1.16%, it is still significant. Often patients are treated with a hip fixation device, such as a sliding hip screw or X-Bolt. This study aimed to investigate the influence of three factors on the likelihood of head collapse: (1) implant type; (2) the size of the femoral head; and (3) the size of the AVN lesion.

Finite element (FE) models of an intact femur, and femurs implanted with two common hip fixation designs, the Compression Hip Screw (Smith & Nephew) and the X-Bolt (X-Bolt Orthopaedics), were developed. Experimental validation of the FE models on 4^th generation Sawbones composite femurs (n=5) found the peak failure loads predicted by the implanted model was accurate to within 14%. Following validation on Sawbones, the material modulus (E) was updated to represent cancellous (E=500MPa) and cortical (E=1GPa) bone, and the influence of implant design, head size, and AVN was examined. Four head sizes were compared: mean male (48.4 mm) and female (42.2 mm) head sizes ± two standard deviations. A conical representation of an AVN lesion with a lower modulus (1MPa) was created, and four different radii were studied. The risk of head collapse was assessed from (1) the critical buckling pressure and (2) the peak failure stress.

The likelihood of head collapse was reduced by implantation of either fixation device. Smaller head sizes and greater AVN lesion size increased the risk of femoral head collapse. These results indicate the treatment of intertrochanteric fractures with a hip fixation device does not increase the risk of head collapse; however, patient factors such as small head size and AVN severity significantly increase the risk.

There is a lack of information about the association between patellofemoral osteoarthritis (PFOA) and both adolescent Anterior Knee Pain (AKP) and previous patellar dislocations.

This case-control study involved 222 participants from our knee arthroplasty database answering a questionnaire. 111 patients suffering PFOA were 1:1 matched with a unicompartmental tibiofemoral arthritis control group. Multivariate correlation and binary logistic regression analysis was performed, with odds ratios (ORs) and 95% confidence intervals (CIs) calculated. This analysis helps us assess the effect of both variables whilst adjusting for major confounders, such as previous surgery and patient-reported instability.

An individual is 7.5 times more likely to develop PFOA if they have suffered adolescent AKP (OR 7.5, 95% CIs 1.51–36.94). Additionally, experiencing a patellar dislocation increases the likelihood of development of PFOA, with an adjusted odds ratio of 3.2 (95% CIs 1.25–8.18). A 44-year difference in median age of first dislocation was also observed between the groups.

This should bring into question the traditional belief that adolescent anterior knee pain is a benign pathology. Patellar dislocation is also a significant risk factor. These patients merit investigation, we encourage clinical acknowledgement of the potential consequences when encountering patients suffering from anterior knee pain or patellar dislocation.

Introduction

The majority of primary total hip arthroplasty (THA) procedures performed throughout the world use modular junctions, such as the trunnion-head interface; however, the failure of these press-fit junctions is currently a key issue that may be exacerbated by the use of large diameter heads. Several factors are known to influence the strength of the initial connection, however, the influence of different head sizes has not previously been investigated. The aim of the study was to establish whether the choice of head size influences the initial strength of the trunnion-head connection.

Cement-induced thermal osteonecrosis is well documented, as is the potential for nerve injury from thermal energy. Cement is often used to augment fixation following excision of humeral metastases. Porcine femurs were used as a model. We sought to find out the maximum temperatures that would be reached in various parts of the bone during the cement setting process, to explore what negative effects this might have on neighbouring bone and nerve.

A 12mm by 12mm window was cut from 12 porcine femoral shafts, and Palacos R+D cement injected into the defect. As cement set, bone surface temperature was measured using infra-red thermal imaging and thermocouples used to measure temperatures at the bone-cement interface, 5mm from the cement bolus, 10mm from cement bolus and an area running around the shaft replicating radial nerve.

Bone surface temperature rose to a maximum of 34.0 C (on average), and 32.9 C in the ‘radial nerve’ thermocouple. Notably, in two bones there were fractures during specimen preparation, and maximum temperatures in these two areas exceeded 41 degrees C.

Average maximum temperatures were 58.1 C, 36.5 C and 30.1 C at the bone cement interface, 5mm and 10mm from the cement bolus respectively.

Triple-tapered cemented stems were developed in the hope that they would reduce aseptic loosening and prevent calcar bone loss.

Between March 2005 and April 2008, a consecutive series of 415 primary C-stem AMT hip arthroplasties in 386 patients were performed under the care of three surgeons at our institution. When all the patients had reached the 5-year anniversary of surgery, functional questionnaires were sent out by mail. In the event of non-response, reminders were sent by post before the patients were contacted by telephone. Postoperative radiographs were also reviewed.

Follow-up ranges from 60 to 99 months, with a mean of 76 months. 32 hips (8%) were lost to follow-up. The median OHS was 40, median SF-12 mental component score (MCS) was 50, and median SF-12 physical component score (PCS) was 39. Radiographic review showed that aseptic femoral component loosening has yet to be observed. At 99 months follow up, stem survivorship is 96.9% (95% confidence interval (CI) 82.5 to 99.5). Adverse events such as calcar fracture, greater trochanter fracture and dislocation were rare at <1%.

The C-stem AMT demonstrates excellent implant survivorship at 5–8 year follow-up, as well as good midterm functional outcome.

Introduction: Radiolucency in the DeLee and Charnley zone 1 of the acetabulum in the early post operative period is a strong predictor of long-term failure of the cemented acetabulum. There is a wide variety in the acetabular anatomy of patients presenting for total hip replacement. Zone 1 radiolucency is an indicator of the failure of penetration of cement into the relatively hard cortical bone encountered in zone 1. Cement penetration is achieved by adequate preparation, achieving containment and effective pressurisation.

Aim: To use pre operative radiological measurements to predict the risk of radiolucency around the cemented acetabular component post operation.

Hypotheses:

Dysplastic acetabuli are associated with a higher incidence of zone 1 radiolucency.

Materials and Methods: A cohort of 300 patients undergoing cemented THR in our institution was identified. Radiographs performed on the patients pre operatively, post operatively, at first follow up (6 weeks to 3months) and follow up at 1 year were analysed. The following measurements of the native acetabulum were performed: Tonnis grade of osteoarthritis, Crowe grade of dysplasia, acetabular index of depth to width, ACM angle, peak to edge distance, acetabular index of weight bearing zone, centre-edge angle of Widberg, acetabular angle of Sharp, cross over sign and posterior wall sign to assess retroversion, acetabular inclination and anteversion angle. Post operative films were then assessed for the presence of zone 1 keyholes, incidence and degree of radiolucency, cup inclination and anteversion.

Results: Patients with an acetabulum outside the normal range were more likely to have a post operative radiolucency. Radiolucency tended to progress with time. Zone 1 keyholes appeared to terminate this progression. Retroverted and steeply inclined acetabuli demonstrated a higher incidence of radiolucency. A large change in version from the native to prosthetic acetabulum was associated with an increased risk of radiolucency.

Conclusion: Thorough pre operative radiological assessment of the acetabular anatomy allows us to predict patients at high risk of post operative radiolucency. Patients with unsuitable anatomy may be more appropriate for an alternative method of fixation or require different techniques of acetabular preparation or augmentation in order to reduce their risk of loosening of the acetabular component in the long term.

Sixty four patients undergoing total hip replacement (THR) were randomized to receive a peri-articular intra-operative multi modal drug injection or to receive no injection. All patients received patient controlled analgesia (PCA) for 24 hours after surgery.

Patients receiving the peri-articular injection showed significantly less PCA consumption 6 hours postoperatively (P< 0.002). The 24 hour PCA requirement post surgery was also less (P< 0.009).

The VAS score for pain on activity in the post anaesthetic care unit (PACU) was significantly less for injected patients (P< 0.04). The VAS satisfaction score for injected patients in the PACU and 4 hours post-operatively showed no statistical difference.

Peri-articular intra-operative injection with multimodal drugs can significantly reduce post-operative patient controlled analgesia requirements and pain on activity in patients undergoing total hip replacement with no apparent increase in risk.

Background: The principal cause of late failure of the cemented acetabular component is aseptic loosening. The acetabulum is a horse shoe of cortico-cancellous bone surrounding a cortical fovea. The cancellous bone becomes denser and less porous peripherally, limiting cement penetration. A radiolucent line in the DeLee and Charnley zone 1 of the acetabulum increases the risk of loosening of the acetabular component by 38.8 times. We propose that the use of 0.5cm keyholes in zone 1 decreases the incidence of zone 1 radiolucency.

Materials and Methods: Two contemporous cohorts of 100 patients were analysed for the incidence of zone 1 radiolucency on the first post operative film. In one cohort, zone 1 keyholes were used and in the other they were not. The films were analysed independently by two blinded investigators. The incidence, length and thickness of any radiolucency were recorded.

Results: The cohort of patients in which zone 1 keyholes were used demonstrated a 9% incidence of any zone 1 radiolucency, 8% were of 1mm width or greater and 2% involved 50% or more of the zone. In the cohort of patients in which zone 1 keyholes were not used the incidence of zone 1 radiolucency was 40% with 29% demonstrating a width of 1mm or greater and 12% affecting 50% or more of the zone.

Conclusions: The use of peripheral keyholes aids penetration of cement into the denser peripheral acetabular bone as demonstrated by decreased rates of post operative zone 1 radiolucency. This decrease in the incidence of early radiolucency should result in lower rates of subsequent loosening of the acetabular component.

Introduction: Fresh autogenous cancellous bone graft is the material of choice in reconstruction and fusion procedures in foot and ankle surgery. There are many potential donor sites for graft harvest, all with recognised minor and major complications. The proximal tibia is one such potential site, and is particularly suited to foot and ankle surgery being within the operative field and under tourniquet control.

Purpose: To assess pain, morbidity and ability to weight bear in a large group of patients undergoing foot and ankle surgery utilising cancellous bone graft from the proximal tibia.

Method: A retrospective audit was undertaken of 148 procedures performed over a period of five years. Minimum follow-up was 3 months. Data were obtained from operation notes and patient interview.

Results: Most patients had no pain (78%) or very mild pain (20%) at the site of graft harvest immediately following surgery. At review, 96% had no pain; 4% had very mild pain with certain activities such as kneeling. There were no major complications. 4 patients (2.7%) had persisting areas of parasthaesia at review, but none were troubled by it. One patient had a superficial wound problem that resolved. The ability to bear weight was dictated by the primary procedure. Usually this was from 2–3 weeks. There were no complications related to early weight bearing in this series.

Conclusion: The proximal tibia is a suitable and safe site for bone graft harvest for foot and ankle surgery. There is no need for additional restriction in weight bearing following this procedure.