Abstract

Aims

The International Consensus Meeting on Musculoskeletal Infection (ICM, Philadelphia 2018) recommended histology as one of the diagnostic tests although this is not routinely used in a number of UK hospitals. This study aims to explore the role of histology in the diagnosis of infection and whether it is of practical use in those cases where the microbiology samples are either diagnostically unclear or do not correspond to the pre-operative diagnosis or the clinical picture.

Femoral impaction bone grafting (IBG) may be used to restore bone stock in revision total hip arthroplasty (THA) and allow use of a shorter, than otherwise, length prosthesis. This is most beneficial in young patients who are more likely to require further revision surgery. This study aimed to assess the results of femoral IBG for staged revision THA for infection. A prospective cohort of 29 patients who underwent staged revision THA for infection with femoral IBG and a cemented polished double-tapered (CPDT) stem at the final reconstruction was investigated.

The minimum follow-up was two years (2 – 10 years, median 6 years). Stem subsidence was measured with radiostereometric analysis. Clinical outcomes were assessed with the Harris Hip, Harris Pain, and and Société Internationale de Chirurgie Orthopédique et de Traumatologie Activity (SICOT) Scores. The original infection was eradicated in 28 patients. One patient required a repeat staged revision due to re-infection with the same organism. At two-year follow-up, the median subsidence at the stem-bone interface was −1.70 mm (−0.31 to −4.98mm). The median Harris Hip Score improved from 51 pre-operatively to 80 at two years (p=0.000), the Harris Pain Score from 20 to 44 (p=0.000) and the SICOT Score from 2.5 to 3 (p=0.003).

As successful eradication of infection was achieved in the majority of patients and the stem migration was similar to that of a primary CPDT stem, this study supports the use of femoral IBG during the final reconstruction of the femur after staged revision THA for infection.

Introduction

The Birmingham Hip Resurfacing (Smith & Nephew London, UK) is the most popular hip resurfacing (HR) in the UK. However, it is now subject to two Medical Device Alerts (MDA) from the Medicines and Healthcare products Regulatory Agency (MHRA).

Introduction:

Wear debris from articulating joint implants is inevitable. Small debris particles are phagocytosed by macrophages. Larger particles initiate the fusion of many macrophages into multi-nucleated giant cells for particle encasement. Macrophages are recruited into inflamed tissues from the circulating monocyte population. Approximately 10% of white blood cells are monocytes which after release from the bone marrow circulate for 2–3 days, before being recruited into tissues as inflammatory macrophages or undergoing apoptosis. Circulating MRP8/14 (S100A8/A9) is a measure of monocyte recruitment, part of the monocyte-endothelial docking complex, and shed during monocyte transmigration across the endothelium. The higher the S100A8/A9 the more monocytes being recruited giving an indirect measure of debris production.

Introduction:

The risk factors for degenerative joint disease are well established: increasing age, obesity, joint abnormalities, trauma and overuse, together with female gender, ethnic and genetic factors. That obesity is a significant risk factor for developing osteoarthritis in non-weight-bearing as well as weight-bearing and joints was one of the first indications that the risk was nor purely that of aberrant biomechanical loading. Low grade chronic systemic inflammation is a component of each of ageing and obesity, atherosclerosis and diabetes, culminating in Metabolic Syndrome. In our study of 1684 patients with joint degeneration 85% were overweight or obese and 65% older than 65 years with 62% being both, 73% of patients were taking medications for serious, ‘non-orthopaedic’ health problems such as cardiovascular or respiratory disease, obesity or NIDDM. Monocytes are a major component of chronic inflammation, approximately 10% of white blood cells are monocytes which circulate for 2–3 days, before being recruited into tissues as inflammatory macrophages or undergoing apoptosis. Circulating S100A8/A9 (MRP8/14) is a measure of monocyte recruitment being shed during monocyte transmigration across the endothelium. The higher the S100A8/A9 the more monocytes being recruited giving an indirect measure of chronic inflammatory status.

In this review, we present the data of one of the largest non-designer, mid- to long-term follow ups of the AGC.

We present a total of 1538 AGC knees during a 15 year period, of which 902 were followed up by postal or telephone questionnaire focused on Oxford Knee Scores, Visual analogues of function and pain and survival analyses performed. Mean length of follow up was 10.4 years.

85.7% of patients had an Oxford knee score of between 0 and 40, with 71.2% scoring between 0–30.

65.6% of patients responded with a Visual Analogue Score (VAS) of 0 or 1 at rest (minimum pain 0) and 53.9% reporting VA scores of 0 or 1 while walking.

87.5% of patients reported Excellent or good functional reports at final follow up and 90.3% reporting excellent or good pain control compared to per-operative levels.

Survival analysis confirms excellent survivorship.

This large cohort and multi-surgeon trial reproduces the excellent results as demonstrated by the designer centre (Ritter et al.). Mid to long term outcome sows excellent function and analgesia. Complication rates are low and the necessity for revision remains low.

Introduction

The Oxford Total Meniscal Knee (TMK by Biomet), is a total knee replacement with a multidirectional mobile bearing. As part of the evaluation of the TMK we compared our group of TMK knee replacements with an equivalent cohort of AGC total knee replacements.

Purpose

To review the outcomes of patients undergoing manipulation under anaesthetic (MUA) after primary total knee arthroplasty (TKA) and predict those that may require such a procedure.

Purpose

This study investigates the effect of early tourniquet release on range of flexion following total knee replacement, and the influence of anticoagulation with Rivaroxaban and Clexane (Enoxaparin).

Purpose

To review the outcomes of patients undergoing manipulation under anaesthetic (MUA) after primary total knee arthroplasty (TKA) and predict those that may require such a procedure.

Introduction: Lumbar disc disease comprises of a heavy portion of the workload in spinal as well as general orthopaedic clinic.

It is well accepted that nerve root tension signs such as straight leg raise (SLR) & Lasegue’s test are sensitive at diagnosing nerve root impingement secondary to lumbar disc degeneration. In isolation, however, they lack specificity & have a poor positive predictive value (PPV). This can lead to uncertainty in clinical diagnosis.

Our study proves that a structured approach to clinical examination with cumulative nerve root tension signs (RTS) significantly increases the tests’ specificity and PPV, therefore giving clinicians more confidence in their diagnosis.

Methods: Prospective review of 1303 patients seen in one Orthopaedic consultant’s spinal clinic from 2004 until 2008. Data was collected using a standardized proforma. Pattern of pain as well as RTS (SLR, Lasegue, bowstring and crossover) were recorded and cross-referenced with subsequent MRI findings. In our dataset a positive MRI result was one in which the demonstrated disc lesion and nerve impingement corresponded with patient symptoms. Patients included were all those presenting with lower back and/or neuropathic leg pain. Patients had to be excluded from series due to incomplete datasets & missing MRI scans.

Results: N = 858. Our results showed that as we progressed from 1 RTS up to 4 RTS there was a significant increase in the PPV : 1RTS PPV = 0.333 (CI 0.25 – 0.43), 2RTS PPV = 0.78 (CI 0.69 – 0.86), 3RTS PPV 0.87 (CI 0.81 – 0.91), 4RTS PPV 0.93 (CI 0.66 – 0.99). There was also significant increases in specificity compared with 1RTS: 1RTS 0.75 (CI 0.70 – 0.8), 2RTS 0.94 (CI 0.91 – 0.96), 3RTS 0.92 (CI 0.89 – 0.95), 4RTS 0.99 (CI 0.98 – 0.99).

Discussion: This study shows that combining root tension signs as part of a structured assessment leads to a significant cumulative increase in the PPV and specificity of the diagnosis of nerve root impingement. Hence proving the importance of clinical examination. This method of sequential, cumulative RTS has not previously been documented in the literature.

Aim: To compare the in-vitro elution characteristics of CMW1 and Palacos R bone cements containing gentamicin or teicoplanin or a combination of both.

Materials & Methods: Four types of bone cement discs (28x22mm) were prepared.

Disc 1(control) contained Palacos R or CMW1 cement without any added antibiotic.

The discs containing teicoplanin were prepared by adding teicoplanin powder (2gm) to the respective cement powder (40 gm with or without 0.5gm of gentamicin) and then adding the monomer (vacuum mixing).

All the discs were immersed in 50 ml normal saline bath in a sterile pot and maintained at temperature of 37 deg Celsius. 24 hours later a 5ml sample was taken from each pot for assay, to measure the amount of antibiotic eluted, using fluorescence polarization immuno-assay technique. The discs were then removed from the pots, washed with normal saline and reimmersed in a fresh 50 ml saline pot. This procedure was repeated at hours 48, 72, 120 and week 1, 2, 3 & 6 for all discs.

Results: All discs and assays were done in triplicate and average total value at 6 weeks (μ gm/ml) taken for statistical analysis.

CMW1:

Gentamicin eluted from disc4 was higher than disc2 (94.9 v 34.37. p< 0.0003).

PALACOS R:

Gentamicin eluted from disc4 was higher than disc2 (144.17 v 86.43. p< 0.0004).

Conclusion: Palacos R cement elutes more antibiotic than CMW1 and antibiotic combination in bone cement resulted in, mostly, synergistic effect of increased elution of individual antibiotic.

We present a prospective trial examining the effect of posterior tibial slope at total knee arthroplasty (TKA) on the range of movement and functional outcome.

Current literature shows little difference clinically in TKA with increasing posterior tibial slope. Previous studies have been retrospective or involved small numbers and may represent poor ligament balancing or inaccurate alignment.

In a prospective, double-blinded, randomised controlled trial, 250 patients undergoing primary Profix TKA, were randomised to receive either a 0 or 4 degree posterior tibial cut. Range of movement (ROM) was measured pre-operatively, at 3 months and 1 year by a single clinical physiotherapist. SF-12 and WOMAC scores were calculated at the same visit. Both patient and physiotherapist were blinded to the angle of tibial slope.

Mean one year post operative ROM was greater by 2 degrees (p=0.470) in those with a 4 degree tibial slope. Post operatively both groups had significant improvement in functional outcome scores. A 0.2 (p= 0.892) and 0.51 (p= 0.707) greater improvement in SF12 physical score and mental scores respectively was found in the 0 degree group at one year. There was also a 1.09 (p=0.718) greater improvement in WOMAC score with a 0 degree slope.

In conclusion increased posterior tibial slope gives a marginally better but non-significant post operative ROM and makes no significant difference to functional outcome.