Establishing a range of motion boundary for total hip arthroplasty.

Range of motion of the hip joint is a major contributor to dislocation post total hip replacement. Impingement is often treated as a surrogate for dislocation and occurs--prosthetically--when the neck of the femoral component contacts with the rim of the pelvic acetabular cup. This impingement is caused by movement of the leg during activities of daily living. This article analyses hip joint range of motion and its implication for impingement. A systematic literature review was undertaken with the purpose of establishing a range of motion benchmark for total hip replacement. This paper proposes a method by which a three-dimensional range of motion boundary established from the literature can be presented. The nominal boundary is also validated experimentally using a number of configurations of a neutral hip joint coordinate frame.

Retrospective evaluation of episodic collapse in the horse in a referred population: 25 cases (1995-2009).

BACKGROUND: Episodic collapse in horses has equine welfare and human safety implications. There are, however, no published case series describing this syndrome. OBJECTIVES: To characterize the cause and outcomes for horses referred for investigation of episodic collapse. ANIMALS: Twenty-five horses referred for investigation of single or multiple episodes of collapse. METHODS: Retrospective study. Clinical records from the Dick Vet Equine Hospital, University of Edinburgh from November 1995 to July 2009 were searched using the following keywords: collapse, collapsing, fall, syncope. Collapse was defined as an incident in which the horse lost postural tone with or without progression to recumbency and with or without loss of consciousness. Long-term follow-up information was obtained by telephone conversation with the owner. RESULTS: A final diagnosis was reached in 11 cases, namely cardiac arrhythmia (4), right-sided heart failure (1), hypoglycemia (2), generalized seizures (2), and sleep disorder (2). A presumptive diagnosis was reached in 8 cases, namely neurocardiogenic syncope (5), exercise-induced pulmonary hemorrhage (2), and generalized seizures (1). No diagnosis was reached in 6 cases despite comprehensive investigations. Three horses were euthanized at presentation. Treatment was attempted in 9 horses with 6 cases having successful outcome before discharge. Follow-up information was available for 14 of 19 horses discharged from the hospital. Only 1 of these horses was observed to collapse after discharge. CONCLUSIONS AND CLINICAL IMPORTANCE: Definitive diagnosis was more likely to be reached in cases with multiple episodes of collapse. Horses in which 1 episode of collapse occurred did not necessarily collapse again.

Noninvasive quantification of ambulatory venous hemodynamics during elastic compressive therapy.

Quantifying the hemodynamic results of elastic compression requires invasive and cumbersome techniques. Twenty lower extremities (normal, primary, acute and chronic post-thrombotic varicosities) were evaluated with quantitative photoplethysmography (PPG) prior and subsequent to initiating graded compression. The PPG transducer is placed against the stockings and the in vivo method of calibration is used to predict the results of compressive therapy on ambulatory venous pressure (AVP). (table see text) Noninvasive evaluation of patients with quantitative PPG techniques following compressive therapy may provide a better understanding of venous hemodynamics and a rational approach to selection of therapy.

Prediction of amputation wound healing. Roles of Doppler ultrasound and digit photoplethysmography.

Segmental limb blood pressures (BPs) measured by Doppler ultrasound and digit photoplethysmography were used to define hemodynamic correlates of wound healing in 122 lower-extremity amputations for ischemia. Healing of digit or transmetatarsal amputations were influenced by the presence of diabetes and correlated better with digit pulsation and BP than with ankle pressure. Healing of below-knee amputation did not correlate with segmental limb BPs. In the absence of an absolute threshold to predict wound healing or failure, caution is urged in using hemodynamic indices to select the level of amputation of arterial insufficiency.