Level IV, prospective study of case series.

Over the past 30 years joint replacement prostheses have been developed and refined to enhance durability and reproducibility. Total hip joint arthroplasty is being performed in an increasing number of younger patients; therefore orthopaedic surgeons seek implants with a longer life span. With regards to the progress of mechanical behaviour of the biomaterials used in an arthroplasty, little is known about the long-term biological effects of wear debris. Owing to the composition of the prostheses currently in use, systemic exposure to chromium (Cr), cobalt (Co), nickel (Ni) and aluminium (Al) alloys occurs as a result of the formation of metal wear nano-particles that are released both from metal-on-metal and polyethylene-on-metal bearings, resulting in a postoperative increase in metal ion levels at different organ sites. These particles circulate both locally and systemically, penetrate cell plasma membranes, bind to cellular proteins and enzymes and modulate cytokine expression. Their physiologic effects are poorly understood and their potential toxicity, hypersensitivity and carcinogenicity remain a cause for concern. In this article we will address the issue of whether these nanoscale degradation products are associated with adverse, clinically significant local or systemic toxicologic sequelae.

Lateral parapatellar approach combined with TTO may prove highly beneficial in significant valgus deformities, as the anatomical axis is restored accurately and soft tissue release of the lateral contracted structures facilitated to an important extent.

The majority of orthopaedic surgeons even currently agree that primary total arthroplasty in valgus knees with a deformity of more than ten degrees may prove challenging. The unique sets of bone and soft tissue abnormalities that must be addressed at the time of the operation make accurate axis restoration, component orientation and joint stability attainment a difficult task. Understanding the specific pathologic anatomic changes associated with the valgus knee is a prerequisite so as to select the proper surgical method, to optimize component position and restore soft-tissue balance. The purpose of this article is to review the valgus knee anatomical variations, to assess the best pre-operative planning and to evaluate how to choose the grade of constraint of the implant. It will also be underlying the up-to-date main approaches and surgical techniques be proposed in the English literature both for bone cuts and soft tissue management of valgus knees.

IntroductionThere has been a recent increase in the incidence of myositis worldwide. To this date, myositis has been described almost exclusively in children and adolescents. In most cases the causative agents are Gram-positive bacteria. When it involves muscles around the hip, other differential diagnoses such as septic arthritis and transient synovitis need to be excluded amongst others.Case presentationWe present the case of a 16 year old Caucasian male who suffered from pyomyositis of his left obturator internus muscle. He was pyrexial at 41°C with rigors and severe hip pain, whilst range of motion of his left hip was severely limited. Tenderness over the left pubic bone was significant. After clinical examination and relevant laboratory investigations, it was decided to treat him conservatively with intravenous antibiotics. Blood cultures grew Staphylococcus aureus resistant to amoxicillin and ampicillin. The patient was discharged fifteen days later. At the time of discharge, he was symptom-free.ConclusionThis form of pyomyositis is a rare pyogenic infection, which may be difficult to diagnose and can easily be missed. Therefore, physicians should familiarise themselves with this condition and consider it as a possible differential diagnosis in patients presenting with an acutely painful hip.