Abstract

Abstract

A subgroup of patients that undergo TKR surgery have evidence of neuropathic pain and central sensitization that may predispose to severe postoperative pain. This study assesses the correlation of MRI detected bone marrow lesions (BMLs) and synovitis with markers of neuropathic pain and central sensitization in patients undergoing TKR surgery and healthy volunteers.

31 patients awaiting TKR and 5 healthy volunteers were recruited. Each subject underwent a 3-T knee MRI scan that was graded for BMLs (0–45) and synovitis (0–3) using subsets of the MRI Osteoarthritis Knee Score (MOAKS). All subjects were asked to complete the PainDetect questionnaire to identify nociceptive pain (< 13), unclear pain (13–18) and neuropathic pain (>18). Correlation between BMLs and PainDetect score was the primary outcome measure. Secondary outcomes included the correlation of synovitis to PainDetect and temporal summation (TS) a measure of central sensitization to the PainDetect score. TS was determined using a monofilament to evoke pain. Pilot histological analysis of the prevalence of osteoclasts (TRAP⁺) within BMLs versus normal subchondral bone was performed, implying a role in BML pathology.

Increasing BML MOAKS score correlated with neuropathic pain (painDetect), r_s = 0.38, p=0.013 (one-tailed). There was a positive correlation between synovitis and PainDetect score, τ =0.23, p= 0.031 (one-tailed). TS was greater in the neuropathic pain than in nociceptive pain patients, U = 18.0, p=0.003 (one-tailed). TRAP staining identified more osteoclasts within BMLs than contralateral condyle lesion free subchondral bone, z = −2.232, p = 0.026 (Wilcoxon Signed Rank Test, one-tailed).

BMLs and synovitis are more prevalent in neuropathic pain and central sensitization in knee OA. Higher osteoclast prevalence was seen within BMLs which may help explain the association with BMLs and pain in OA.

Painful OA is linked to CNS changes in pain processing. Temporal summation of pain (TSP) is a measure of one such CNS change, central sensitization. TSP is defined using a series (≥0.33Hz) of painful stimuli and is a predictor of postoperative pain, experienced by 20% of patients after total knee replacement (TKR) surgery. This study has developed a protocol to use functional MRI to assess CNS changes in OA pain processing.

This pilot includes 3 participants with chronic knee OA pain awaiting TKR (62 ± 4.4) and 5 healthy volunteers (50 ± 13.6). 3-Tesla BOLD fMRI brain scans were recorded during short series of one second painful stimuli, applied using an automated inflatable cuff to the calf muscle of the leg with the affected knee or left side in healthy volunteers. The pain intensity at onset and during the 10 painful stimuli were recorded using a numerical rating scale. The pattern of brain activation was averaged across noxious stimuli, and the differential activation compared the 1st vs. 10th (last) stimulus. Bone marrow lesions (BMLs), synovitis and effusion size were scored from 3-Tesla knee MRI's using MOAKS scoring.

TSP was raised in OA patients compared to control group (p=0.023). TSP brain activity in the chronic OA patients displayed higher signal within the subgenual anterior cingulate (sgACC) compared to healthy volunteers. Knee MRI identified OA patient's exhibited higher BML scores (p=0.038) and more knee effusion (p=0.018), but the lack of synovitis did not differ from control group (p=0.107).

Enhanced TSP in chronic knee OA pain may be linked with augmented responses in emotional circuitry. BMLs and effusion size appear to contribute more with pain than synovitis. These results may help understand sensitization to improve outcomes for patients with knee OA undergoing TKR surgery.

Paediatric distal radial and forearm fractures account for 37.4% of all fractures in children. We present our 2.5-year results of a novel safe approach to the treatment of simple distal radial and diaphyseal fractures using intranasal diamorphine and entonox in a designated fracture reduction room in the emergency department.

All simple fractures of the distal radius and forearm admitted to our ED between March 2012 and August 2014 that could be reduced using simple manipulation techniques were included in this study. These included angulated diaphyseal fractures of the forearm, angulated metaphyseal fractures of the distal radius and Salter Harris types I and II without significant shortening. All children included were given intranasal diamorphine as well as entonox. The orthopaedic registrar on call performed all reductions.

100 children had their distal radius or forearm fracture reduced in the emergency department using entonox and diamorphine analgesia and had a same day discharge. Average age was 10 years (range 2.20–16.37 years). No complications were reported regarding the use of the analgesia and all children and parents were pleased with their treatment not requiring a hospital admission. The mean initial dorsal angulation of all fracture types was 28.05° degrees (23.91–32.23 95% CI) which was reduced to 7.03° (5.11–8.95 95% CI) post manipulation. There were 9 cases lost to follow up. Two cases lost the initial reduction of the fracture on subsequent clinic follow up and underwent internal fixation in theatre.

The use of entonox and intranasal diamorphine is a safe, effective treatment of providing adequate analgesia for children with distal radial and forearm fractures to allow manipulation of displaced dorsally angulated fractures in the emergency department. By facilitating a same day discharge, over £45,000 was saved using this safe method of treatment.

Patients presenting with a fractured neck of femur are a fragile group with multiple co-morbidities who are at risk of post-operative complications. As many as 52% of patients are reported to suffer a urinary tract infection post hip fracture surgery. There are little data surrounding the effects of post-operative urinary tract infections on mortality and deep prosthetic infection.

We prospectively investigated the impact of post-operative urinary tract infection (UTI) in 9168 patients admitted to our institution with a diagnosis of proximal femoral fracture over an eleven year period in a prospective population study. We examined the effects of post operative UTI on the incidence of deep infection, survivorship and length of stay.

Post-operative UTI occurred in 6.1% (n=561) and deep infection in 0.89% (n=82). Deep infection was significantly more common in patients complicated with a UTI (3.2% vs 0.74% p< 0.001) with a relative risk of 3.7:1. In 58% of patients the same organisms was cultured in the urine and hip samples. A postoperative UTI did not adversely effect 90 day survival, however was associated with an increased length of stay (ROC analysis AUC=0.79). Delays to surgery and age were not predictive of a post operative UTI.

Recognition of the risks posed by post operative UTI, the risk factors for development of infection and early treatment is essential to reduce the risks of increased subsequent periprosthetic infection.

Objective

To determine the reliability, reproducibility, variability and validity of the Osteoarthritis Research Society International (OARSI) Osteoarthritis Cartilage Histopathology (OACH) system and Mankin Histopathology – Histochemical Grading System (HHGS) when applied to the characterisation of the osteoarthritic human knee.

Background: Autologous bone graft remains the “gold standard”, but the associated morbidity and finite supply of tissue has resulted in surgeons seeking methods of enhancing healing with bone graft substitutes and bone morphogenic proteins (BMPs). There are 54 bone graft substitutes and 2 BMPs currently on sale in the UK. The aim of this study was to review the published clinical evidence in support of their use in spinal surgery.

Methods: The 19 manufacturers of bone graft substitutes and BMPs were contacted asking for details of their products on the market. A systematic literature review was conducted using the ISI Web of Knowledge, EMBASE (1980–2008) and OVID databases. Publications providing clinical data were classified according to the hierarchy of clinical evidence published in the Journal of Bone and Joint Surgery Am in 2003. Level I evidence is a prospective randomised control trial with definitive results to support the use of an intervention in a clinical setting. Level V evidence is isolated case reports. A Grade of recommendation A-i was accredited to each product to assist the clinical spinal surgeon in making decisions on which product to use based on the evidence in the literature.

Results: 102 clinical studies found, most of which were level IV or V evidence. Both BMPs, InductOS® and OP-1® have Level I papers and have Grade A recommendation. There is very poor evidence for the use of bone graft substitutes in spinal surgery with no products receiving Grade A recommendation and only 6 out of 54 products having Grade B recommendation.

Conclusions: There is a lack of evidenced based clinical data for the use of bone graft substitutes in spinal surgery. Regarding BMPs there is good evidence for the use of these products in spinal surgery but surgeons must be aware of the reported complications.