The number of arthroplasties being performed increases each year. Patients undergoing an arthroplasty are at risk of venous thromboembolism (VTE) and appropriate prophylaxis has been recommended. However, the optimal protocol and the best agent to minimise VTE under these circumstances are not known. Although many agents may be used, there is a difference in their efficacy and the risk of bleeding. Thus, the selection of a particular agent relies on the balance between the desire to minimise VTE and the attempt to reduce the risk of bleeding, with its undesirable, and occasionally fatal, consequences.

Acetylsalicylic acid (aspirin) is an agent for VTE prophylaxis following arthroplasty. Many studies have shown its efficacy in minimising VTE under these circumstances. It is inexpensive and well-tolerated, and its use does not require routine blood tests. It is also a ‘milder’ agent and unlikely to result in haematoma formation, which may increase both the risk of infection and the need for further surgery. Aspirin is also unlikely to result in persistent wound drainage, which has been shown to be associated with the use of agents such as low-molecular-weight heparin (LMWH) and other more aggressive agents.

The main objective of this review was to summarise the current evidence relating to the efficacy of aspirin as a VTE prophylaxis following arthroplasty, and to address some of the common questions about its use.

There is convincing evidence that, taking all factors into account, aspirin is an effective, inexpensive, and safe form of VTE following arthroplasty in patients without a major risk factor for VTE, such as previous VTE.

Cite this article: Bone Joint J 2017;99-B:1420–30.

Aims

Medial unicompartmental knee arthroplasty (UKA) is associated with successful outcomes in carefully selected patient cohorts. We hypothesised that severity and location of patellofemoral cartilage lesions significantly influences functional outcome after Oxford medial compartmental knee arthroplasty.

Many aspects of total knee arthroplasty have changed since its inception. Modern prosthetic design, better fixation techniques, improved polyethylene wear characteristics and rehabilitation, have all contributed to a large change in revision rates. Arthroplasty patients now expect longevity of their prostheses and demand functional improvement to match. This has led to a re-examination of the long-held belief that mechanical alignment is instrumental to a successful outcome and a focus on restoring healthy joint kinematics. A combination of kinematic restoration and uncemented, adaptable fixation may hold the key to future advances.

Cite this article: Bone Joint J 2015;97-B(10 Suppl A):16–19.

Infected periprosthetic fractures around total hip arthroplasties are increasingly common and extremely challenging problem. The purpose of the study was to review the experience of two tertiary referral units managing infected periprosthetic femoral fractures using interlocking long-stem femoral prostheses either as temporary functional spacers or as definitive implants.

Introduction

Up to 2% of total hip arthroplasties (THA) are still complicated by infection. This leads to dissatisfied patients with poor function, and has far-reaching social and economic consequences. The challenge in these cases is the eradication of infection, the restoration of full function and the prevention of recurrence. We report the outcome of early aggressive debridement in the acutely infected THA.

Introduction

There have been concerns regarding the quality of training received by Orthopaedic trainees. There has been a reduction in working hours according to the European working times directive. National targets to reduce surgical waiting lists has increased the workload of consultants, further reducing the trainees' surgical experience. Navigation assisted procedures are successfully used in orthopaedics and provides useful feedback to the surgeon regarding precision of implant placement. We investigated the use of navigation aids as an alternative source of training surgical trainees.

Introduction

In recent years, there has been a significant advancement in our understanding of femoro-acetabular impingement and associated labral and chondral pathology. Surgeons worldwide have demonstrated the successful treatment of these lesions via arthroscopic and open techniques. The aim of this study is to validate a simple and reproducible classification system for acetabular chondral lesions.

Introduction

Up to 2% of total knee arthroplasties (TKA) are still complicated by infection. This leads to dissatisfied patients with poor function, and has far-reaching social and economic consequences. The challenge in these cases is the eradication of infection, the restoration of full function and the prevention of recurrence.

We report the outcome of prosthesis sparing early aggressive debridement in the acutely infected TKA.

Introduction

Unicondylar knee replacements (UKR) may be more effective compared to Total knee replacements (TKR) in unicompartmental arthritis. We report patient outcomes & satisfaction data in an age matched cohort of patients with either a UKR or TKR.

Purpose: To determine if a multi-modal programme including non-operative measures of physiotherapy and education can improve the symptoms of osteoarthritis of the knee.

Methods/Results: 72 patients with osteoarthritis of the knee confirmed on radiographic or arthroscopic evidence were referred over a 13 month period (April 2007 – May 2008) for a lower limb programme. The programme consisted of 12 classes over 6 weeks of group physiotherapy and included education on osteoarthritis, diet and exercise.

The total number of knees affected was 98. The mean number of compartments affected was 1.2 with the medial and patellofemoral compartment most affected. The mean number of classes attended was 8.3. Pre-intervention, the mean WOMAC score was 64.7 and the mean Oxford knee score was 31.9. Post-intervention at a mean follow up of 12 months (range 7 – 22 months), the mean WOMAC score was 29.4 and the mean Oxford knee score 22.4. The change in scores following intervention was statistically significant (p < 0.05). Of the cohort, 9 patients were subsequently offered or went on to have knee joint arthroplasty.

Conclusions: At 12 months, a multi-modal programme consisting of non-operative interventions has an excellent impact upon osteoarthritis of the knee with improved patient reported scores. This modality should be considered for all patients with mild to moderate osteoarthritis in whom surgical options are not otherwise indicated. Further work is required to see which components most influenced patients’ outcomes, the impact of education and group classes on maintaining physiotherapy exercises in the long term, the benefits conferred even for those patients who subsequently undergo joint arthroplasty, and whether referral to the programme from a primary care setting will lower the number of referrals of knee osteoarthritis to orthopaedic units which are ultimately managed without surgical intervention.

Aim: To ascertain if a medial rotation platform knee replacement design (MRK; Finsbury Orthopaedics) exhibits improved range of motion (ROM) and functional outcome compared to a conventional single radius condylar knee replacement system (PFC Sigma; Depuy) at one year.

Methods: Eighty patients undergoing total knee arthroplasty(TKA) were prospectively randomised and allocated to either receive the MRK or PFC Sigma pros-thesis. Patients were blinded to the choice of implant. Follow-up clinical and radiological evaluations were carried out by a single clinician so as to avoid interob-server error. Validated patient based scores including the Total Knee Function Questionnaire (TKFQ) were used to assess patient function.

Results: The average ROM in the MRK group was 108.53°. In the PFC Sigma group it was 94.16°. Statistical significance was demonstrated between the two groups.

The MRK group showed superior results in the TKFQ score which assesses activities of daily living as well as recreational and sporting activities. The movement and lifestyle component of the TKFQ, and the Knee Society Score were better in the MRK group with statistical significance.

No difference was demonstrated between the two groups with respect to radiological analysis, WOMAC Knee, Oxford Knee and SF-36 scores.

6 out of 40 patients in the MRK group compared to 5 out of 40 patients in the PFC group said that they had forgotten about their TKA at one year.

Conclusions: The medial rotation platform design confers increased ROM at one year with an associated benefit in movement and lifestyle and resultant patient satisfaction.

Introduction: The incidence of post-operative peri-prosthetic fractures is increasing. This is a consequence of the larger number of revision cases being undertaken, the increase in the use of cementless implants and a number of patients who develop undetected osteolysis as a result of poor follow up. The Vancouver classification has been shown to be a valid and reliable method for determining the configuration of periprosthetic fractures. This is essential in directing the further management of periprosthetic fractures appropriately.

Methods: We have revalidated this classification system independently from the original authors at our institution. The radiographs from 30 patients with peri-prosthetic fractures were reviewed by 6 expert consultant surgeons, 6 non-experts at registrar level and 6 medical students, who had received no specialist training in this area, in order to assess intra and inter-observer reliability and reproducibility. Each observer read the radiographs on 2 separate occasions and classified the fracture according to its type (A, B1, B2, B3, and C).

Results: The results were subjected to weighted κ analysis and were: Intraobserver agreement 0.72 for experts,0.68 for non experts and 0.61 for medical students. Interobserver agreement was 0.63 for the first reading and 0.67 for the second reading. Validity analysis showed a κ value of 0.79 (substantial agreement).

Discussion: Our results confirm the reliability and reproducibility of this classification system. In addition we have shown that substantial agreement can even be found between individuals with no specialist training. This is a classification system that can be used by non-experts, between centres and across continents.

Background And Aims: Total knee replacements provide a cost effective treatment for painful joint conditions such as osteoarthritis. Their long term performance is governed by ultra-high molecular weight polyethylene (UHMWPE) wear which produces wear debris and leads to osteolysis and aseptic loosening of the implant. Using a new material which is more scratch resistant than cobalt chrome it is hoped to reduce wear of UHMWPE and its subsequent complications.

Methods: Two total knee replacements made from cobalt chrome and two of oxidised zirconium were wear tested in a knee simulator. Surface roughness data from the femoral components was collected. Gravimetric and volumetric wear of the polyethylene inserts was measured. SEM analysis of the surfaces was also performed.

Results: Oxidised zirconium is significantly more scratch resistant than CoCr; Ra (mean average roughness) of 0.7μm compared to 0.43μm (p< < 0.01) at end of test, and confirmed by SEM analysis. This was accompanied by a 4 fold reduction in wear of UHMWPE 49.60mg to 12.48mg (p=0.02). Barium sulphate particles were found to be embedded in the surface of the CoCr implants.

Summary And Conclusions: Oxidised zirconium leads to a reduction in wear of UHMWPE due to its increased resistance to third body wear. It has the potential to increase the longevity of total knee replacements by reducing UHMWPE related complications.

Aims: To quantify the intraoperative cerebral microemboli load during primary total hip arthroplasty (THA) using transcranial Doppler ultrasound and to investigate whether a patent foramen ovale influences cerebral embolic load in general. The timing of the microemboli will be related to certain surgical activities to determine if a specific relationship exists.

Methods: Patients undergoing primary THA, with no history of stroke, TIA, ongoing CNS disease or alcoholism were included. All operations were carried out under a standardised general anaesthetic and performed by two consultant orthopaedic surgeons. Microemboli load was recorded, using transcranial Doppler ultrasound (TCD), onto VHS tape for subsequent playback and analysis. Patent foramen ovale detection was performed using bolus intravenous injection of agitated saline followed by valsalva manoeuvre technique and TCD. Timing of specific surgical steps was recorded for each operation and emboli load calculated for that period.

Results: 25 THA patients were studied (18 females, 7 males) 16 right and 9 left THA’s were performed. Cerebral microembolisation occurred in 10 patients (40%). Mean microembolic load was 5.52 per patient (range = 0–83). PFO was detected in 8 patients (32%). 37.5% of PFO positive patients displayed cerebral microemboli. However, 41.1% of PFO negative patients also displayed microemboli intraoperatively.

Insertion of the femoral component was associated with generating a larger microembolic load than the other phases of the operation.

Conclusion: Intraoperative cerebral microembolisation occurs in a significant proportion of patients during total hip arthroplasty. The presence of a patent foramen ovale does not appear to influence the incidence microemboli intraoperatively. Specific surgical activities are associated with generating greater embolic loads. These questions will be comprehensively assessed in the larger study currently underway..

Introduction: An increasing number of patients present for revision hip replacement with severe bone loss. The results of cemented revision in these cases are poor. This study was conducted to determine the medium term clinical and radiological outcome of 50 consecutive revision hip replacements performed using custom femoral stems.

Materials and Method: 50 consecutive hips (49 patients) performed by the senior author between 1992 and 1995 were identified. The indications for revision were aseptic loosening in 42 cases, infection in 7 cases (6 of which were revised using a two-stage technique), and dislocation in one case. The stems are manufactured on the basis of standardised measurement films using specially developed software. The design includes proximal macrogrooves with hydroxyapatite coating, an anterior flare, a lateral flare and a collar. The average follow up was 88.4 months (range 12–111 months). All patients were evaluated radiologically and using Harris, Oxford and WOMAC hip scores.

Results: The patients were assessed by an independent observer. All had severe bone loss according to AAOS and Paprosky classifications. 5 patients died due to causes unrelated to their hip replacement, 5 were lost to follow up or did not respond to questionnaires sent. The remaining patients had average preoperative scores of HHS 40.8 (range 8–87), Oxford 43.5 (range18–56) and WOMAC 82.5 (range 40–120) and had improved to HHS 74.4 (range 19–99), Oxford 25.5(range 12–51) and WOMAC 43.8 (range 13–89).

Conclusions: The use of customised revision stems allows the implant to be tailored to the patient’s bone stock and femoral anatomy. This technique avoids the massive inventory of implants and trials needed for highly modular revision systems, but nevertheless leads to excellent bone implant apposition and interface stability. The clinical results are excellent at medium term review, and the survivorship compares very favourably with other revision series.