Investigation of thermally induced damage to surrounding nerve tissue when using curettage and cementation of long bone tumours, modelled in cadaveric porcine femurs.

INTRODUCTION: Curettage with cement augmentation is a technique used in the treatment of bone tumours. Thermal energy released during the cement polymerisation process can damage surrounding tissues. This study aims to record temperature changes at various sites on and around bone during the cementing process. We hypothesised that adjacent structures, such as the radial nerve, may be threatened by this process in the clinical setting. MATERIALS AND METHODS: Using 18 porcine femurs as a model of the human humerus, we used thermocouples and a thermal imaging camera to measure changes in temperature during the cementing process. Fractures were created in nine samples to establish whether a discontinuity of the cortex had an effect on thermal conduction. RESULTS: Significantly higher temperatures were recorded in samples with a fracture compared to those without a fracture. The site overlying the centre of the cement bolus (hypothetical site of the radial nerve) demonstrated higher temperatures than all other sites on the same cortex. When considering the radial nerve site, over half the samples demonstrated temperatures exceeding 47 °C for over a minute. When a threshold of 50 °C for more than 30 s was considered, three samples without a fracture exceeded this value compared to two with a fracture. CONCLUSION: The temperatures recorded were sufficient to cause damage to neural tissue. Limiting thermal exposure to soft tissues is recommended. Increased attention is required when using larger cement boluses, or where bone quality is poor or a fracture, iatrogenic or preexisting, is present.

Role of ROCK2 in CD4+ cells in allergic airways responses in mice.

BACKGROUND: Rho kinases (ROCKs) contribute to allergic airways disease. ROCKs also play a role in lymphocyte proliferation and migration. OBJECTIVE: To determine the role of ROCK2 acting within CD4+ cells in allergic airways responses. METHODS: ROCK2-haploinsufficient (ROCK2+/- ) and wild-type mice were sensitized with ovalbumin (OVA). ROCK2+/- mice then received either CD4+ cells from ROCK2-sufficient OVA TCR transgenic (OT-II) mice or saline i.v. 48 h before challenge with aerosolized OVA. Wild-type mice received saline before challenge. Allergic airways responses were measured 48 h after the last challenge. Allergic airways responses were also assessed in mice lacking ROCK2 only in CD4+ cells (ROCK2CD4Cre mice) vs. control (CD4-Cre and ROCK2flox/flox ) mice. RESULTS: OVA-induced increases in bronchoalveolar lavage lymphocytes, eosinophils, IL-13, IL-5, and eotaxin were reduced in ROCK2+/- vs. wild-type mice, as were airway hyperresponsiveness and mucous hypersecretion. In ROCK2+/- mice, adoptive transfer with CD4+ cells from OT-II mice restored effects of OVA on lymphocytes, eosinophils, IL-13, IL-5, and mucous hypersecretion to wild-type levels, whereas eotaxin and airway hyperresponsiveness were not affected. ROCK2 inhibitors reduced IL-13-induced release of eotaxin from airway smooth muscle (ASM), similar to effects of these inhibitors on ASM contractility. Despite the ability of adoptive transfer to restore allergic airways inflammation in ROCK2-insufficient mice, allergic inflammation was not different in ROCK2CD4Cre vs. control mice. CONCLUSION: ROCK2 contributes to allergic airways responses likely via effects within ASM cells and within non-lymphocyte cells involved in lymphocyte activation and migration into the airways.

Personalised 3D Printed high tibial osteotomy achieves a high level of accuracy: 'IDEAL' preclinical stage evaluation of a novel patient specific system.

High tibial osteotomy (HTO) is an effective surgical treatment for isolated medial compartment knee osteoarthritis; however, widespread adoption is limited due to difficulty in achieving the planned correction, and patient dissatisfaction due to soft tissue irritation. The aim of this study was to assess the accuracy of a novel HTO system with 3D printed patient specific implants and surgical guides using cadaveric specimens. Local ethics committee approval was obtained. The novel opening wedge HTO procedure was performed on eight cadaver leg specimens. Whole lower limb CT scans pre- and post-operatively provided geometrical assessment quantifying the discrepancy between pre-planned and post-operative measurements for key variables: the gap opening angle and the patient specific surgical instrumentation positioning. The average discrepancy between the pre-operative plan and the post-operative osteotomy correction angle was: 0.0 ±â€ˆ0.2° The R2 value for the regression correlation was 0.95. The average error in implant positioning was -0.4 ±â€ˆ4.3 mm, -2.6 ±â€ˆ3.4 mm and 3.1 ±â€ˆ1.7° vertically, horizontally, and rotationally respectively. This novel HTO surgery has greater accuracy in correction angle achieved compared to that reported for conventional or other patient specific methods with published data available. This system could potentially improve the accuracy of osteotomy correction angles achieved surgically.

A potential new target for asthma therapy: a disintegrin and metalloprotease 10 (ADAM10) involvement in murine experimental asthma.

BACKGROUND: Elevated levels of CD23, a natural regulator of IgE production, have been shown to decrease the signs of lung inflammation in mice. The aim of this study was to study the involvement of ADAM10, the primary CD23 sheddase, in experimental asthma. METHODS: ADAM10 was blocked either by using mice with a B-cell-specific deletion of the protease or pharmacologically by intranasal administration of selective ADAM10 inhibitors. Airway hypersensitivity (AHR) and bronchoaveolar lavage fluid (BALF) eosinophilia and select BALF cytokine/chemokine levels were then determined. RESULTS: Using an IgE and mast cell-dependent mouse model, B-cell-specific ADAM10(-/-) mice (C57B/6 background) exhibited decreased eosinophilia and AHR when compared with littermate (LM) controls. Treatment of C57B/6 mice with selective inhibitors of ADAM10 resulted in an even further decrease in BALF eosinophilia, as compared with the ADAM10(-/-) animals. Even in the Th2 selective strain, Balb/c, BALF eosinophilia was reduced from 60% to 23% respectively. In contrast, when an IgE/mast cell-independent model of lung inflammation was used, the B-cell ADAM10(-/-) animals and ADAM10 inhibitor treated animals had lung inflammation levels that were similar to the controls. CONCLUSIONS: These results thus show that ADAM10 is important in the progression of IgE-dependent lung inflammation. The use of the inhibitor further suggested that ADAM10 was important for maintaining Th2 levels in the lung. These results thus suggest that decreasing ADAM10 activity could be beneficial in controlling asthma and possibly other IgE-dependent diseases.

Clinical prioritisation of revision knee surgical procedures: BASK working group consensus document.

BACKGROUND: Elective orthopaedic surgery during the Covid-19 pandemic requires careful case prioritisation. We aimed to produce consensus-based guidelines on the prioritisation of revision total knee arthroplasty (TKA) procedures. METHOD: Twenty-three revision TKA scenarios were assigned priority (NHS England/Royal College of Surgeons scale) by the British Association for Surgery of the Knee (BASK) Revision Knee Working Group (n = 24). Consensus agreement was defined as ≥70% respondents (18/24) giving the same prioritisation. Two voting rounds were undertaken; procedures achieving <70% agreement were given their most commonly assigned priority. RESULTS: 18/23 procedures achieved ≥70% agreement. Three were P1a (surgery within <24 h); DAIR for sepsis, peri-prosthetic fracture (PPF) fixation and PPF-revision TKA. Three were P1b (<72 h); debridement, antibiotics and implant retention (DAIR) for a stable patient, flap coverage for an open knee, and acute extensor mechanism rupture. Eight were P2 (<4 weeks), including aseptic loosening at risk of collapse, inter-stage patients with poor functioning spacers. Five were P3 (<3 months), including second stage revision for infection, revision for instability with limited mobility. Four were P4 (can wait >3 months) e.g. aseptic loosening. CONCLUSION: Sepsis and PPF surgery are the most urgent procedures. Although most procedures should be undertaken within one to three months (P2/3), these cases represent a small revision practice volume; P4 cases (e.g. aseptic loosening without risk of collapse) make up most surgeons' caseload. These recommendations are a guideline; patient co-morbidities, Covid-19 pathways, availability of support services and multi-disciplinary team discussion within the regional revision network will dictate prioritisation.

Revision knee replacement surgery in the NHS: A BASK surgical practice guideline.

BACKGROUND: Revision knee replacement (KR) is both challenging for the surgical team and expensive for the healthcare provider. Limited high quality evidence is available to guide decision-making. AIM: To provide guidelines for surgeons and units delivering revision KR services. METHODS: A formal consensus process was followed by BASK's Revision Knee Working Group, which included surgeons from England, Wales, Scotland and Northern Ireland. This was supported by analysis of National Joint Registry data. RESULTS: There are a large number of surgeons operating at NHS sites who undertake a small number of revision KR procedures. To optimise patient outcomes and deliver cost-effective care high-volume revision knee surgeons working at high volume centres should undertake revision KR. This document outlines practice guidelines for units providing a revision KR service and sets out: The current landscape of revision KR in England, Wales and Northern Ireland. Service organisation within a network model. The necessary infrastructure required to provide a sustainable revision service. Outcome metrics and auditable standards. Financial mechanisms to support this service model. CONCLUSIONS: Revision KR patients being treated in the NHS should be provided with the best care available. This report sets out a framework to both guide and support revision KR surgeons and centres to achieve this aim.

The symptomatic adult flatfoot: Is there a relationship between severity and degree of pre-existing arthritis in the foot and ankle?

BACKGROUND: The acquired adult flatfoot deformity (AFFD) is a potentially debilitating foot condition with a prevalence thought to be between 3 %-10 %. To the authors' best knowledge, no association has been described between severity of AFFD and degree of pre-existing ankle or foot arthritis. The degree and pattern of preexisting ipsilateral arthritis of the foot and ankle was investigated in those with symptomatic AFFD presenting to hospital. METHODS: Retrospective observational study between May 2015 and May 2018, of patients who presented to our tertiary clinic with symptomatic AFFD. Radiographs of one hundred and forty-eight (n=148) patients were reviewed, excluding those with charcot arthropathy, previous trauma or coalition. The primary outcome measure was severity of OA in the ankle, subtalar, talonavicular and calcaneocuboid joints. Secondary outcome was severity of radiographic planovalgus deformity. The independant variables used were age and severity of planovalgus deformity as measured by the Meary angle, calcaneal pitch and medial cuneiform-fifth metatarsal height. A linear regression model was carried out on the outcomes. RESULTS: Median age was 60.0 years (IQR 22). There were 56 males to 92 females, with 75 left sided deformities observed and 73 right sided. With increasing severity of planovalgus measurements, there was no significant association observed in severity of arthritis in the ankle joint (p = 0.766), subtalar joint (p = 0.090), talonavicular joint (p = 0.256) and calcaneocuboid joint (p = 0.091). With increasing age, there was significance observed in degree of ankle arthritis, subtalar, talonavicular and calcaneocuboid joints (p = 0.001). There was no significant correlation observed with age for the angular break of Meary's line (p = 0.73), calcaneal pitch (0.262) and medial cuneiform-fifth metatarsal height (p = 0.937). CONCLUSION: This observational study shows no significant association between severity of radiographic planovalgus deformity and pre-existing arthritis of the ankle, hindfoot and midtarsal joints.

Investigation and management of prosthetic joint infection in knee replacement: A BASK Surgical Practice Guideline.

BACKGROUND: The burden of knee replacement prosthetic joint infection (KR PJI) is increasing. KR PJI is difficult to treat, outcomes can be poor and it is financially expensive and limited evidence is available to guide treatment decisions. AIM: To provide guidelines for surgeons and units treating KR PJI. METHODS: Guideline formation by consensus process undertaken by BASK's Revision Knee Working Group, supported by outputs from UK-PJI meetings. RESULTS: Improved outcomes should be achieved through provision of care by revision centres in a network model. Treatment of KR PJI should only be undertaken at specialist units with the required infrastructure and a regular infection MDT. This document outlines practice guidelines for units providing a KR PJI service and sets out: CONCLUSIONS: KR PJI patients treated within the NHS should be provided the best care possible. This report sets out guidance and support for surgeons and units to achieve this.

Provision of revision knee surgery and calculation of the effect of a network service reconfiguration: An analysis from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man.

BACKGROUND: Revision knee replacement (KR) is technically challenging, expensive, and outcomes can be poor. It is well established that increasing surgeon and unit volumes results in improved outcomes and cost-effectiveness for complex procedures. The aim of this study was to 1) describe the current provision of revision KR in England, Wales and Northern Ireland at the individual surgeon and unit level and 2) investigate the effect on workload of case distribution in a network model. METHODS: Current practice was mapped using NJR summary statistics containing all revision KR procedures performed over a three-year period (2016-2018). Units were identified as revision centres based on threshold volumes. Units undertaking <20 revisions per year were classified as Primary Arthroplasty Units (PAUs) in calculations on the effect of workload centralisation. RESULTS: Revision KR was performed by 1353 surgeons at 232 NHS sites. The majority of surgeons and units were low-volume; >1000 surgeons performed <7 and 125 sites performed <20 procedures per year. Reallocation of work from these 125 PAUs (1235 cases, 21% of total workload) to a network model with even redistribution of cases between centres undertaking revision surgery would result in an additional average annual case increase of 11 per unit per year (range six to 14). CONCLUSIONS: Revision KR workload re-allocation would lift all revision centres above a 30 per year threshold and would appear to be a manageable increase in workload for specialist revision KR centres. Case complexity and local referral agreements will significantly affect the real increase in workload; these factors were not incorporated here.

Single-stage orthoplastic reconstruction of Gustilo-Anderson Grade III open tibial fractures greatly reduces infection rates.

BACKGROUND: Grade III open fractures of the tibia represent a serious injury. It is recognised that combined management of these cases by experienced orthopaedic and plastic surgeons improves outcomes. Previous studies have not considered the timing of definitive soft tissue cover in relation to the definitive orthopaedic management. This paper reviews the outcomes in patients treated in an orthoplastic unit where the emphasis was on undertaking the definitive orthopaedic and plastic surgical procedures in a single stage, following initial debridement and temporary stabilisation as necessary. METHODS: We reviewed medical notes of 73 consecutive patients with 74 Grade III open tibia fractures (minimum 1 year follow up), to compare deep infection rates in patients who had (a) a single-stage definitive fixation and soft tissue coverage vs. those who had separate operations, and (b) those who had definitive treatment completed in <72h vs. >72h. RESULTS: (a) Combined Single-stage Orthoplastic Fixation and Coverage: 48 fractures were managed with definitive orthopaedic fixation and plastic surgical coverage performed at the same time, whilst 26 had these performed at separate stages. Of those subjects that had definitive fixation and coverage in one procedure 2 (4.2%) developed deep infections, compared with 9 (34.6%) deep infections (p<0.001) in those who underwent definitive fixation and coverage at separate operations. (b) Timing of surgery: Of the fractures that had definitive fixation and coverage completed within 72h of injury, 5 (20%) developed deep infections, compared with 6 (12.2%) deep infections (p=0.492) in those whose definitive fixation/coverage was completed at later than 72h. CONCLUSION: Joint orthoplastic operating lists facilitate simultaneous definitive fixation and cover that greatly reduces infection rates. Based on our experience presented in this paper, we believe that emphasis should be placed on timely transfer to a specialist centre, aiming for a single-stage combined orthoplastic procedure to achieve definitive fixation and soft tissue coverage and optimal outcomes.

Wasting of the small hand muscles in upper and mid-cervical cord lesions.

Four patients are described with destructive rheumatoid arthritis of the cervical spine and neurogenic wasting of forearm and hand muscles. The pathological connection is not immediately obvious, but a relationship between these two observations is described here with clinical, radiological, electrophysiological and necropsy findings. Compression of the anterior spinal artery at upper and mid-cervical levels is demonstrated to be the likely cause of changes lower in the spinal cord. These are shown to be due to the resulting ischaemia of the anterior part of the lower cervical spinal cord, with degeneration of the neurones innervating the forearm and hand muscles. These findings favour external compression of the anterior spinal artery leading to ischaemia in a watershed area as the likeliest explanation for this otherwise inappropriate and bizarre phenomenon.

Stereotactic and ultrasound core needle breast biopsy performed by surgeons.

BACKGROUND: The authors evaluated outcomes and treatment costs of stereotactic core needle biopsy (SCNB) and ultrasound core needle biopsy (UCNB), and needle localization biopsy (NLB) in managing patients with mammographic abnormalities presenting to the surgeon. METHODS: Data for all patients with mammographic lesions who underwent SCNB or UCNB since their introduction at this institution were prospectively collected over 17 months. Mean inclusive costs of the three procedures were accumulated and compared. RESULTS: Stereotactic core needle biopsy was performed for 342 lesions in 319 women, for a malignancy rate of 19%; UCNB was performed for 157 lesions in 144 patients, yielding a malignancy rate of 17%. With a mean follow-up of 13.5 months, 1 patient with in situ carcinoma was diagnosed late. Absolute cost savings for the period studied was $721,963. CONCLUSIONS: Minimally invasive breast biopsy procedures can safely and reliably be performed by surgeons in clinical practice with increased patient convenience and decreased costs.

Combination endovascular and open treatment of peripheral arterial occlusive disease performed by surgeons.

The endovascular treatment of peripheral arterial occlusive disease has historically been performed by interventional radiologists and cardiologists. With additional training in endovascular techniques, surgeons become uniquely suited to manage arterial lesions with both endovascular and conventional surgical techniques. Over a 14-month period, 13 patients underwent combination endovascular and open reconstruction on limbs with peripheral arterial occlusive disease. There were 10 males and 3 females. The mean age was 66 years. All procedures were performed in the operating room by surgery residents under the direct supervision of vascular surgeons. After intraoperative angiography, 26 arterial lesions underwent percutaneous transluminal angioplasty (aorta, 1; common iliac, 14; external iliac, 10; superficial femoral, 1). Twenty-five of 26 lesions were further treated with intraluminal stent placement, the lone exception being a case of superficial femoral artery angioplasty. Concomitant open reconstruction was performed on all limbs, 14 as outflow and 1 as inflow. There were two cases of procedural morbidity and one perioperative death secondary to myocardial infarction. There were no wound-related complications. The mean ankle-brachial index of the affected lower extremity improved from 0.41 (+/- 0.15) to 0.74 (+/- 0.14) at 30 days. Mean follow-up was 8 months (range, 2-14). Based on our early experience, simultaneous combination endovascular and open reconstruction of multisegment arterial occlusive disease can be performed safely and efficiently by surgeons.

Reactive arthritis due to Yersinia enterocolitica.

Two cases are reported of a reactive arthritis due to infection with Yersinia enterocolitica. These are the fifth and sixth cases reported in the United Kingdom. This interesting cause of arthritis may be more common than previously thought and should be considered even in the United Kingdom, although the practical implications are limited.