Validation of the ultrasonographic assessment of the femoral trochlea epiphyseal cartilage in foals at osteochondrosis predilected sites with magnetic resonance imaging and histology.

BACKGROUND: Noninvasive imaging tools are needed to screen foal femoropatellar joints to detect subclinical osteochondrosis lesions due to focal failure of endochondral ossification to enhance early management to optimise intrinsic healing events. Recently investigations employing 3T susceptibility-weighted magnetic resonance imaging (3T SWI MRI) and CT have demonstrated their capacity for early osteochondrosis diagnosis, but these technologies are not practical for field screening. We postulate that ultrasonography is a valuable field tool for the detection of subclinical osteochondrosis lesions. OBJECTIVES: The goals were to 1) describe the ultrasonographic features of the femoral trochlea of healthy and osteochondrosis-predisposed neonatal foals, 2) validate the capacity of ultrasound to assess cartilage canal vascular archictecture and the ossification front and 3) evaluate field feasibility in a pilot study. STUDY DESIGN: Experimental study. METHODS: Ultrasonographic evaluation of osteochondrosis predisposed (n = 10) and control (n = 6) femoral trochleas was performed ex vivo and compared with site-matched histological sections and 3T SWI MRI. The articular and epiphyseal cartilage thickness, ossification front indentation and cartilage canal vascular archictecture were assessed at each ROI. Femoral trochleae of foals (n = 3) aged ≈ 1, 3 and 6 months were also evaluated with ultrasonography in field. RESULTS: Ultrasonographic measurements strongly correlated with the histological measurements. There was no difference in the cartilage thickness or ossification front indentation between control and osteochondrosis-predisposed specimens. The cartilage canal vascular archictecture on ultrasonograms corresponded with the vessel pattern observed on site matched histology and 3T SWI MRI. MAIN LIMITATIONS: The number of specimens for study was limited and no early osteochondrosis lesions were present within the predilected group, but a field study is now underway. CONCLUSION: Ultrasonographic examination of the femoral trochlea permitted accurate evaluation of cartilage thickness, cartilage canal vascular archictecture and ossification front indentation in young foals and is a promising, practical tool for screening subclinical osteochondrosis and monitoring and managing lesions at important clinical sites.

Use of routine clinical multimodality imaging in a rabbit model of osteoarthritis--part II: bone mineral density assessment.

OBJECTIVE: To assess bone mineral density (BMD) at different depths from the articular surface in vivo and temporally in a rabbit model of osteoarthritis (OA) using clinical computed tomography (CT) equipment. METHODS: The knee joints of rabbits (N=10 with Anterior cruciate ligament transection (ACLT) and contralateral sham joints, and N=6 unoperated controls) were scanned in a transverse image plane with a single-slice helical CT scanner. BMD was calculated at defined depths from the articular surface to the growth plate in the lateral femoral condyle (LFC), medial femoral condyle (MFC), lateral tibial plateau (LTP) and medial tibial plateau (MTP). Baseline BMD was measured at 2 weeks before surgery, and then repeated at weeks 2, 4 and 8 post-surgery in all 10 operated rabbits, and again at week 12 in five of the operated rabbits and at weeks -2 and 8 in the six control rabbits. RESULTS: In the control joints, BMD decreased with increasing distance into the epiphysis and remained stable over time within each depth. A significant reduction in BMD was observed at week 2 post-operatively in three compartments (LFC, MFC and MTP) in the ACLT joints and persisted to week 12. A modest reduction in BMD occurred in the LTP and MTP of the sham joints at week 12 alone. CONCLUSION: Clinical CT equipment permitted rapid, repeated, in vivo, non-invasive BMD assessment in a rabbit model of OA. A marked BMD reduction was measured with progression of OA until the end point at 12 weeks.

Designing an incentive compensation program that works.

To encourage innovation and improve departmental and organizational bottom lines, Winchester Hospital, Winchester, Massachusetts, developed and implemented a middle management and staff incentive compensation plan. Middle managers and staff who participate in projects that provide savings to the hospital are paid a share of the savings. The plan allows staff the option of designing "horizontal" projects, in which a project leader carries out a project individually or with peers, or "vertical" projects, in which a project leader directs a team of key individuals. Increasing numbers of vertical projects have been proposed since the plan's inception in 1994. In addition to increasing the hospital's operating income, the program provides cost-effective, variable compensation, which especially appeals to motivated, high-performing employees; motivates employees to overcome roadblocks; facilitates a team approach that bridges traditional departmental boundaries; and encourages a beneficial and collegial competitiveness among managers.