ABSTRACT
Knee arthroscopy for meniscal tears is one of the most commonly performed orthopaedic procedures. In recent years, there has been an increasing incidence of meniscal repairs, as there are concerns that meniscectomy predisposes patients to early osteoarthritis. Indications for meniscal repair are increasing and can now be performed in older patients who are active, even if the tear is in the avascular zone. Options for meniscal tear management broadly fall into three categories: non-operative management, meniscal repair or meniscectomy. With limited evidence directly comparing each of these options optimal management strategies can be difficult. Decision making requires thorough assessment of patient factors (e.g. age and comorbidities) and tear characteristics (e.g. location and reducibility). The purpose of this paper is, therefore, to review the management options of meniscal tears and summarize the evidence for meniscal tear repair.
Subject(s)
Arthroscopy/methods , Meniscectomy/methods , Tibial Meniscus Injuries/therapy , Age Factors , Chronic Disease , Clinical Decision-Making , Humans , Menisci, Tibial/blood supply , Tibial Meniscus Injuries/pathology , Tibial Meniscus Injuries/rehabilitationABSTRACT
Hypoxic pulmonary vasoconstriction (HPV) is a beneficial mechanism that diverts blood from hypoxic alveoli to better ventilated areas of the lung, but breathing hypoxic air causes the pulmonary circulation to become hypertensive. Responses to airway hypoxia are associated with depolarization of smooth muscle cells in the pulmonary arteries and reduced activity of K(+) channels. As Kv7 channels have been proposed to play a key role in regulating the smooth muscle membrane potential, we investigated their involvement in the development of HPV and hypoxia-induced pulmonary hypertension. Vascular effects of the selective Kv7 blocker, linopirdine, and Kv7 activator, flupirtine, were investigated in isolated, saline-perfused lungs from rats maintained for 3-5 days in an isobaric hypoxic chamber (FiO2 = 0.1) or room air. Linopirdine increased vascular resistance in lungs from normoxic, but not hypoxic rats. This effect was associated with reduced mRNA expression of the Kv7.4 channel α-subunit in hypoxic arteries, whereas Kv7.1 and Kv7.5 were unaffected. Flupirtine had no effect in normoxic lungs but reduced vascular resistance in hypoxic lungs. Moreover, oral dosing with flupirtine (30 mg/kg/day) prevented short-term in vivo hypoxia from increasing pulmonary vascular resistance and sensitizing the arteries to acute hypoxia. These findings suggest a protective role for Kv7.4 channels in the pulmonary circulation, limiting its reactivity to pressor agents and preventing hypoxia-induced pulmonary hypertension. They also provide further support for the therapeutic potential of Kv7 activators in pulmonary vascular disease.
Subject(s)
Hypoxia , KCNQ Potassium Channels/metabolism , Lung , Pulmonary Circulation , Aminopyridines/pharmacology , Analgesics/pharmacology , Animals , Gene Expression Regulation/drug effects , Hypertension, Pulmonary/metabolism , Hypertension, Pulmonary/pathology , Hypertension, Pulmonary/physiopathology , Hypoxia/metabolism , Hypoxia/pathology , Hypoxia/physiopathology , Indoles/pharmacology , KCNQ Potassium Channels/antagonists & inhibitors , Lung/blood supply , Lung/metabolism , Lung/pathology , Lung/physiopathology , Male , Membrane Potentials/drug effects , Muscle, Smooth/metabolism , Muscle, Smooth/pathology , Muscle, Smooth/physiopathology , Potassium Channel Blockers/pharmacology , Pulmonary Artery/metabolism , Pulmonary Artery/pathology , Pulmonary Artery/physiopathology , Pyridines/pharmacology , Rats , Rats, Wistar , Vascular Resistance/drug effectsABSTRACT
BACKGROUND: Epidural fibrosis (EF) represents a frequent and poorly manageable complication of lumbar disk surgery. OBJECTIVES: To investigate the influence of perioperative Epidural Steroid (ES) application on the development of EF. METHODS: One hundred and seventy eight patients underwent L4/5 or L5/S1 discectomy. The study group receiving ES comprised of eighty five patients, and a further control group comprising eighty two patients received a placebo. At a 12 month follow-up, all subjects underwent contrast magnet resonance imaging of the lumbosacral spine. One hundred and sixty seven patients filled in a predetermined questionnaire containing the Visual Analogue Scale (VAS; pain scale) during the first postoperative days and 12 months after. Intergroup differences were analysed and a correlation between the extent of EF and VAS was examined. RESULTS: The groups did not differ regarding the extent of EF. There was a statistically significant correlation between the degree of fibrosis and VAS (P<0.05). However, there was no significant difference in subjective pain assessment between both groups 12 months postoperatively. The application of ES did not influence their return to work. Patients receiving ES experienced less pain on the first and third days after surgery. The average hospital stay after surgery was shorter in the steroid treated group (4.5 days) compared to 5.2 days in the control group (p<0.05). CONCLUSIONS: The application of ES did not prove to be useful in the prevention of Failed Back Surgery Syndrome and epidural scar formation. Postoperative pain was decreased in the steroid treated group during the first postoperative week, but not 12 months postoperatively.
