An investigation of composition, morphology, mechanical properties, and microdamage accumulation of human type 2 diabetic bone.

This study investigates the biomechanics of type 2 diabetic bone fragility through a multiscale experimental strategy that considers structural, mechanical, and compositional components of ex vivo human trabecular and cortical bone. Human tissue samples were obtained from the femoral heads of patients undergoing total hip replacement. Mechanical testing was carried out on isolated trabecular cores using monotonic and cyclic compression loading and nanoindentation experiments, with bone microdamage analysed using micro-computed tomography (CT) imaging. Bone composition was evaluated using Raman spectroscopy, high-performance liquid chromatography, and fluorometric spectroscopy. It was found that human type 2 diabetic bone had altered mechanical, compositional, and morphological properties compared to non-type 2 diabetic bone. High-resolution micro-CT imaging showed that cores taken from the central trabecular region of the femoral head had higher bone mineral density (BMD), bone volume, trabecular thickness, and reduced trabecular separation. Type 2 diabetic bone also had enhanced macro-mechanical compressive properties under mechanical loading compared to non-diabetic controls, with significantly higher apparent modulus, yield stress, and pre-yield toughness evident, even when properties were normalised against the bone volume. Using nanoindentation, there were no significant differences in the tissue-level mechanical properties of cortical or trabecular bone in type 2 diabetic samples compared to controls. Through compositional analysis, higher levels of furosine were found in type 2 diabetic trabecular bone, and an increase in both furosine and carboxymethyl-lysine (an advanced glycation end-product) was found in cortical bone. Raman spectroscopy showed that type 2 diabetic bone had a higher mineral-to-matrix ratio, carbonate substitution, and reduced crystallinity compared to the controls. Together, this study shows that type 2 diabetes leads to distinct changes in both organic and mineral phases of the bone tissue matrix, but these changes did not coincide with any reduction in the micro- or macro-mechanical properties of the tissue under monotonic or cyclic loading.

Do joint-preserving hip procedures compromise subsequent total hip arthroplasty? A meta-analysis of complications, functional outcome and survivorship.

BACKGROUND: Joint-preserving hip operations can help relieve pain and delay the need for long-term joint arthroplasty. Previous research has not identified procedures that can compromise outcomes following total hip arthroplasty (THA). This meta-analysis aims to evaluate the effect of joint-preserving hip operations on outcomes following subsequent THA. METHODS: MEDLINE, EMBASE and Scopus databases were searched from the date of inception until February 2024. All studies comparing outcomes following THA in individuals with (PS) and without prior surgery (NPS) of the femur or pelvis were included. Data on operative time, blood loss, intra- and post-operative complications, functional outcomes, and implant survivorship were extracted. RESULTS: 16 studies, comprising 2576 patients were included (PS = 939, NPS = 1637). The PS group was associated with significantly longer operative time [MD: 8.1, 95% CI: 4.6-11.6], significantly greater blood loss [MD: 167.8, 95% CI: 135.6-200.0], and a higher risk of intra-operative peri-prosthetic fracture [RR: 1.9, 95% CI: 1.2-3.0], specifically, with prior femoral osteotomy. There were no differences in terms of risks of dislocation [RR: 1.8, 95% CI: 1.0-3.2], implant loosening [RR: 1.0, 95% CI: 0.7-1.5], or revision surgery [RR: 1.3, 95% CI: 1.0-1.7] between the two groups. The PS group was associated with significantly poorer improvements in functional outcome [MD: -5.6, 95% CI: -7.6-(-3.5)], specifically, with prior acetabular osteotomy. Implant survivorship in the two groups was comparable after one year [HR: 1.9, 95% CI: 0.6-6.2] but significantly inferior in the PS group after five years [HR: 2.5, 95% CI: 1.4-4.7], specifically, with prior femoral osteotomy. CONCLUSION: Joint-preserving hip operations are associated with greater intra-operative challenges and complications. In subsequent joint arthroplasty, prior acetabular procedures affect functional outcomes while prior femoral procedures influence implant survivorship. Hip pain due to the morphological sequelae of pediatric hip pathology can be debilitating at a young age. Surgical decision-making at that time needs to consider the survivorship of a THA implanted at that young age against the consequences of hip preservation surgery on further THA.

Simultaneous bilateral total hip arthroplasty-a survey of Irish orthopaedic surgeons' practice.

BACKGROUND: Bilateral total hip arthroplasty may be performed simultaneously (SIMTHA) or in two staged operations. AIM: To assess attitudes towards and utilization of SIMTHA in Irish orthopaedic practice, and to assess patient and surgeon factors which are associated with the management of bilateral hip arthritis. METHODS: A 16-question electronic survey (Google Forms) was distributed via email to consultant Irish orthopaedic surgeons who perform total hip arthroplasty, followed by a reminder 1 month later. A p value < 0.05 was considered significant. RESULTS: There were 53 responses from arthroplasty surgeons, with 28% reporting they never perform SIMTHA, 26% have performed ≤ 5 SIMTHA, and 46% do ≥ 1 SIMTHA per year. Amongst the 15 surgeons who do not do SIMTHA, 60% reported a preference for staged arthroplasty, 20% felt it was not feasible in their institution, and a third reported a lack of experience with SIMTHA. There was a significant association between not performing SIMTHA and years of consultant experience (p = 0.002). There were no institutional guidelines on eligibility criteria for SIMTHA. The most common time interval for staged bilateral arthroplasty was 6-12 weeks (60%). Overall, 56% of surgeons felt SIMTHA is underutilised in the Irish healthcare system; this was associated with greater SIMTHA volume (p = 0.023). CONCLUSION: Half of the Irish arthroplasty surgeons report SIMTHA is a regular aspect of their practice. Performing SIMTHA is associated with greater arthroplasty volume, more recent consultant appointments, and a perception that the operation is underutilised.

Bilateral tibial fractures associated with powered exoskeleton use in complete spinal cord injury - a case report & literature review.

INTRODUCTION: Powered robotic exoskeleton (PRE) physiotherapy programmes are a relatively novel frontier which allow patients with reduced mobility to engage in supported walking. Research is ongoing regarding their utility, risks, and benefits. This article describes the case of two fractures occurring in one patient using a PRE. CASE: We report the case of a 54 year old man who sustained bilateral tibial fractures while using a PRE, on a background of T10 AIS A SCI. The initial session was discontinued due to acute severe bilateral knee swelling after approximately 15 min. The patient attended their local hospital the following day, where radiographs demonstrated bilateral proximal tibial fractures. The patient was treated with manipulation under anaesthetic and long-leg casting for five weeks, at which point he was stepped down to hinged knee braces which were weaned gradually while he remained non-weight bearing for 12 weeks. The patient was investigated with DEXA scan and was diagnosed with osteoporosis. He was liaised with rheumatology services and bone protection was initiated. Fracture healing was achieved and weight-bearing precautions were discontinued, however this period of immobilisation led to significant spasticity. The patient was discharged from orthopaedic services, with ongoing rehabilitation and physiotherapy follow-up. CONCLUSION: PRE assisted physiotherapy programmes are a promising concept in terms of rehabilitation and independence, however they are not without risk and it is important that both providers and patients are aware of this. Furthermore, SCI patients are at increased risk for osteoporosis and should be monitored and considered for bone protection.

Red blood cell transfusion: 2023 AABB international guidelines

Red blood cell transfusion is a common medical intervention with benefits and harms. To provide recommendations for use of red blood cell transfusion in adults and children. Standards for trustworthy guidelines were followed, including using Grading of Recommendations Assessment, Development and Evaluation methods, managing conflicts of interest, and making values and preferences explicit. Evidence from systematic reviews of randomized controlled trials was reviewed. For adults, 45 randomized controlled trials with 20 599 participants compared restrictive hemoglobin-based transfusion thresholds, typically 7 to 8 g/dL, with liberal transfusion thresholds of 9 to 10 g/dL. For pediatric patients, 7 randomized controlled trials with 2730 participants compared a variety of restrictive and liberal transfusion thresholds. For most patient populations, results provided moderate quality evidence that restrictive transfusion thresholds did not adversely affect patient-important outcomes. Recommendation 1: for hospitalized adult patients who are hemodynamically stable, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). In accordance with the restrictive strategy threshold used in most trials, clinicians may choose a threshold of 7.5 g/dL for patients undergoing cardiac surgery and 8 g/dL for those undergoing orthopedic surgery or those with preexisting cardiovascular disease. Recommendation 2: for hospitalized adult patients with hematologic and oncologic disorders, the panel suggests a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (conditional recommendations, low certainty evidence). Recommendation 3: for critically ill children and those at risk of critical illness who are hemodynamically stable and without a hemoglobinopathy, cyanotic cardiac condition, or severe hypoxemia, the international panel recommends a restrictive transfusion strategy considering transfusion when the hemoglobin concentration is less than 7 g/dL (strong recommendation, moderate certainty evidence). Recommendation 4: for hemodynamically stable children with congenital heart disease, the international panel suggests a transfusion threshold that is based on the cardiac abnormality and stage of surgical repair: 7 g/dL (biventricular repair), 9 g/dL (single-ventricle palliation), or 7 to 9 g/dL (uncorrected congenital heart disease) (conditional recommendation, low certainty evidence). It is good practice to consider overall clinical context and alternative therapies to transfusion when making transfusion decisions about an individual patient.