Purpose: The purpose of this study was to determine, first, if there is measurable deficit in proprioception in an anterior cruciate ligament (ACL)-deficient knee, either compared to the ...contralateral knee or external controls; second, if this deficit, if present, improves after ACL reconstruction; and third, if improvement occurs, what the time course of improvement is.
Type of Study: Prospective cohort study.
Methods: Patients undergoing ACL reconstruction at the University of Chicago, demonstrating a full and painless range of motion and no other knee ligament injury or history of previous knee surgery, were eligible. Twenty-six patients, with an average age of 25 years (range, 16 to 48) were enrolled. Average time from injury to reconstruction was 8 weeks. The patients' contralateral knee served as an internal control, and 26 age-matched and gender-matched healthy volunteers were enrolled as an external control group. ACL reconstructions were performed using a single-incision technique with either bone–patellar tendon–bone or quadrupled hamstring autograft. They were allowed immediate weightbearing as tolerated and participated in a standardized rehabilitation program, with the goal of returning to sport at approximately 6 months. Proprioception testing was carried out using an electrogoniometer, in a seated position. Joint position sense (JPS) and threshold to detection of passive motion (TDPM) were measured preoperatively and at 3 and 6 weeks and 3 and 6 months postoperatively.
Results: Mean KT-2000 values 6 months postoperatively were 1.38 mm (±2). Modified Lysholm score improved significantly (
P < .01). Calculated
r values were 0.65 for JPS and 0.96 for TDPM. No significant differences in postoperative proprioception were found between hamstring and patellar tendon grafts or among patients with meniscus injury, meniscus repair, or chondral injury. Preoperatively, the mean TDPM in both the injured and contralateral knees was significantly higher (worse) than in the external control knees (
P = .008;
P = .016). Evaluation of changes in proprioception from preoperative to 6 months postoperative showed significant improvement in both injured and contralateral knees (
P = .04;
P = .01). At 6-month follow-up, there was no significant difference from controls.
Conclusions: TDPM was a more reliable method than JPS for testing proprioception before and after ACL reconstruction in this study. Bilateral deficits in knee joint proprioception (TDPM) were documented after unilateral ACL injury. Reconstruction of a mechanical restraint (ACL graft) was believed to have a significantly positive impact on early and progressive improvement in proprioception.
The CDF II Level 1 Track Trigger Upgrade Jones, M.; Abulencia, A.; Azzurri, P. ...
IEEE transactions on nuclear science,
02/2008, Letnik:
55, Številka:
1
Journal Article
Recenzirano
The CDF II detector uses dedicated hardware to identify charged tracks that are used in an important class of level 1 trigger decisions. Until now, this hardware identified track segments based on ...patterns of hits on only the axial sense wires in the tracking chamber and determined the transverse momentum of track candidates from patterns of track segments. This identification is efficient but produces trigger rates that grow rapidly with increasing instantaneous luminosity. High trigger rates are a consequence of the large numbers of low momentum tracks produced in inelastic collisions which generate overlapping patterns of hits that match those expected for high-momentum tracks. A recently completed upgrade to the level 1 track trigger system makes use of information from stereo wires in the tracking chamber to reduce the rate of false triggers while maintaining high efficiency for real high momentum particles. We describe the new electronics used to instrument the additional sense wires, identify track segments and correlate these with the track candidates found by the original track trigger system. The performance of this system is characterized in terms of the efficiency for identifying charged particles and the improved rejection of axial track candidates that do not correspond to real particles.
We describe a general search for resonances decaying to a neutral e{mu} final state in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. Using a data sample representing 344 pb{sup -1} of ...integrated luminosity recorded by the Collider Detector at Fermilab II experiment, we compare standard model predictions with the number of observed events for invariant masses between 50 and 800 GeV/c{sup 2}. Finding no significant excess (5 events observed vs 7.7{+-}0.8 expected for M{sub e{mu}}>100 GeV/c{sup 2}), we set limits on sneutrino and Z{prime} masses as functions of lepton family number violating couplings.
We report the first observation of B{sub s}{sup 0}{yields}{psi}(2S){phi} decay in p{bar p} collisions at {radical}(s)=1.96 TeV using 360 pb{sup -1} of data collected by the CDF II detector at the ...Fermilab Tevatron. We observe 20.2{+-}5.0 and 12.3{+-}4.1 B{sub s}{sup 0}{yields}{psi}(2S){phi} candidates, in {psi}(2S){yields}{mu}{sup +}{mu}{sup -} and {psi}(2S){yields}J/{psi}{pi}{sup +}{pi}{sup -} decay modes, respectively. We present a measurement of the relative branching fraction (script B)(B{sub s}{sup 0}{yields}{psi}(2S){phi})/(script B)(B{sub s}{sup 0}{yields}J/{psi}{phi})=0.52{+-}0.13(stat){+-}0.04(syst){+-}0.06(BR) using the {psi}(2S){yields}{mu}{sup +}{mu}{sup -} decay mode.
We report on a measurement of the inclusive jet production cross section as a function of the jet transverse momentum in p{bar p} collisions at {radical}(s)=1.96 TeV using data collected with the ...upgraded Collider Detector at Fermilab in run II, corresponding to an integrated luminosity of 385 pb{sup -1}. The measurement is carried out for jets with rapidity 0.1<|y{sub jet}|<0.7 and transverse momentum in the range 54<p{sub T}{sup jet}<700 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross section after the necessary nonperturbative parton-to-hadron corrections are included.
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