Presentation, examination, investigation and early treatment of acute knee injuries

Muscle damaging eccentric exercise attenuates disuse-induced declines in daily myofibrillar protein synthesis and transiently prevents muscle atrophy in healthy men

Short-term disuse leads to muscle loss driven by lowered daily myofibrillar protein synthesis (MyoPS). However, disuse commonly results from muscle damage, and its influence on muscle deconditioning during disuse is unknown. Twenty-one males [20 ± 1 yr, BMI = 24 ± 1 kg·m^-2 (± SE)] underwent 7 days of unilateral leg immobilization immediately preceded by 300 bilateral, maximal, muscle-damaging eccentric quadriceps contractions (DAM; subjects n = 10) or no exercise (CON; subjects n = 11). Participants ingested deuterated water and underwent temporal bilateral thigh MRI scans and vastus lateralis muscle biopsies of immobilized (IMM) and nonimmobilized (N-IMM) legs. N-IMM quadriceps muscle volume remained unchanged throughout both groups. IMM quadriceps muscle volume declined after 2 days by 1.7 ± 0.5% in CON (P = 0.031; and by 1.3 ± 0.6% when corrected to N-IMM; P = 0.06) but did not change in DAM, and declined equivalently in CON [by 6.4 ± 1.1% (5.0 ± 1.6% when corrected to N-IMM)] and DAM [by 2.6 ± 1.8% (4.0 ± 1.9% when corrected to N-IMM)] after 7 days. Immobilization began to decrease MyoPS compared with N-IMM in both groups after 2 days (P = 0.109), albeit with higher MyoPS rates in DAM compared with CON (P = 0.035). Frank suppression of MyoPS was observed between days 2 and 7 in CON (IMM = 1.04 ± 0.12, N-IMM = 1.86 ± 0.10%·day^-1; P = 0.002) but not DAM (IMM = 1.49 ± 0.29, N-IMM = 1.90 ± 0.30%·day^-1; P > 0.05). Declines in MyoPS and quadriceps volume after 7 days correlated positively in CON (r² = 0.403; P = 0.035) but negatively in DAM (r² = 0.483; P = 0.037). Quadriceps strength declined following immobilization in both groups, but to a greater extent in DAM. Prior muscle-damaging eccentric exercise increases MyoPS and prevents loss of quadriceps muscle volume after 2 (but not 7) days of disuse.NEW & NOTEWORTHY We investigated the impact of prior muscle-damaging eccentric exercise on disuse-induced muscle deconditioning. Two and 7 days of muscle disuse per se lowered quadriceps muscle volume in association with lowered daily myofibrillar protein synthesis (MyoPS). Prior eccentric exercise prevented the decline in muscle volume after 2 days and attenuated the decline in MyoPS after 2 and 7 days. These data indicate eccentric exercise increases MyoPS and transiently prevents quadriceps muscle atrophy during muscle disuse.

Assessment and management of patients with tibial plateau fractures in emergency departments

Tibial plateau fractures are complex injuries and relatively common presentations in emergency departments (EDs), yet the diagnosis is not always obvious. Patients with this injury are managed increasingly in EDs by registered advanced nurse practitioners (RANPs), who are recognised in Ireland as senior clinical decision-makers. RANPs are broadening their scope of practice to maximise their responses to current and emerging challenges in healthcare services. They use a range of skills, including taking comprehensive health histories, problem solving, clinical decision-making and using their expert judgement to diagnose and create management plans for patients who attend EDs. In Ireland, RANP is a protected title and practitioners work within an agreed scope of practice, meeting criteria set by the Nursing and Midwifery Board of Ireland to register. RANPs ensure continuity of care, improve the quality of care, provide a quick response to patient care, reduce waiting times and improve flow of patients through EDs. The main scope of RANPs' practice in emergency care includes management of patients with non-life-threatening limb conditions or injures, such as a tibial plateau fracture. This article gives an overview of tibial plateau fractures, including anatomy, and presents a case study to analyse critically the management of a patient with this injury and the care provided by a RANP. In the context of the case study, the article reviews the RANP's diagnostic decisions and the available management options.

Posterior cruciate ligament injuries

Posterior cruciate ligament (PCL) injuries occur following both high-velocity trauma (motor vehicle collisions) and low-velocity trauma (sporting injuries) with the most common cause being high-velocity trauma resulting in so-called ‘dash board injuries’. In majority of the cases, clinical examination will reveal the presence of a PCL tear; however, magnetic resonance imaging remains the imaging modality of choice if the diagnosis is in doubt. For the most part, isolated PCL tears are relatively benign and can be treated conservatively. PCL avulsion injuries or grade III ruptures may require operative intervention. Postoperative rehabilitation is also an important part of the healing process.