Do hip muscle weakness and dynamic knee valgus matter for the clinical evaluation and decision-making process in patients with patellofemoral pain?

BACKGROUND: Patellofemoral pain is a very common musculoskeletal condition. In the last years, evidence regarding this disease increased exponentially. Although widely investigated, this problem still frustrates patients and clinicians for having an unfavorable prognosis. Some gaps still exist in the understanding and managing of patellofemoral pain. Numerous cross-sectional association studies show an association between gluteus muscular strength and dynamic knee valgus in patients with patellofemoral pain. In spite of this biological plausibility, many evidences challenge the direct relationship between these factors. Recent studies have concluded that women with patellofemoral pain show muscular weakness of the hip based on the cross-sectional studies, however prospective studies indicate that hip weakness cannot be considered a risk for development of patellofemoral pain. In addition, some clinical trials have demonstrated that strength training of the gluteal muscles promotes significant improvement in symptoms but not alter the kinematics of the patients with patellofemoral pain. These findings cast doubt on whether the cause of this condition is really being treated, whether all individuals suffering from patellofemoral pain present dynamic knee valgus or if this is a disturbance present in only a subgroup of patients and whether the strengthening of the hip musculature is an option to consider for prevention of patellofemoral pain. CONCLUSION: Certainly, more studies should be conducted to clarify the influence of mechanical patterns on this condition, but with the existing evidence so far, the importance given to these issues in the evaluation and clinical decision on treatment of these patients seems questionable. Therefore, this masterclass explores the understanding about patellofemoral pain, highlighting mainly the importance of muscular strength and dynamic knee valgus, as well as other possible factors that must be consider during the evaluation and the decision making in these patients.

[Description of a case of infection due to Dracunculoidea in French Polynesia]. / Un cas d'infection à Dracunculoidea en Polynésie française.

The purpose of this report is to describe a case of Dracunculoidea infection that led to acute arthritis of the knee in a young Polynesian. The implications of this first reported case of Dracunculoidea infection in French Polynesia are discussed.

Echinococcal synovitis of the knee joint.

Bone lesions are present in 1% to 2% of cases of hydatid disease. Hydatid synovitis can usually be identified due to secondary extension from the adjacent bone, or infrequently after hematogenous spread. We present an extremely rare case of hydatid synovitis without bony involvement. A 74-year-old man with diagnosed hydatid disease was admitted to our department because of left knee swelling. Neither physical examination nor laboratory studies revealed any remarkable findings. Radiographic evaluation of the knee joint was noncontributory. The patient underwent an arthroscopically assisted synovectomy, and the biopsy revealed an echinococcus contamination. No complications occurred during the postoperative period.

Infective arthritis due to Blastocystis hominis

A patient with rheumatoid arthritis taking prednisone developed Blastocystis hominis acute diarrhoea, which was associated with increased inflammation and effusion of the left knee. B. hominis organisms were found in synovial fluid from the left knee. The patient responded dramatically to metronidazole treatment. B. hominis may become disseminated in immunosuppressed patients with diarrhoea and may cause infective arthritis. (AU)

Infective arthritis due to Blastocystis hominis.

A patient with rheumatoid arthritis taking prednisone developed Blastocystis hominis acute diarrhoea, which was associated with increased inflammation and effusion of the left knee. B hominis organisms were found in synovial fluid from the left knee. The patient responded dramatically to metronidazole treatment. B hominis may become disseminated in immunosuppressed patients with diarrhoea and may cause infective arthritis.

Meta-echinococcal arthrosynovitis: a clinical, anatomical and pathological entity not previously recognised.

The authors describe a case of echinococcosis of the tibia which occurred twice in seven years, the first time with signs of active involvement of the knee joint. Certain special aspects of articular echinococcosis, not up to now reported in the literature, are dealt with. The conclusion reached is that in an articular site the parasite can give rise either to a veritable "echinococcal" arthritis or, as in the case presented, to a the synovial affection which cannot be defined as "echinococcal" because the synovium did not contain living larval forms of the parasite, but only microscopic chitinous inclusions, arising from the disintegration of sterile hydatids, which had escaped from the adjacent bony focus into the joint. The synovium reached to their presence with an intense inflammatory response of a predominantly histiocytic nature. The term "meta-echinococcal arthrosynovitis" is suggested as a more accurate designation of this syndrome.