bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hamstrings—an anterior cruciate ligament protagonist
Authors: More Robert C. , Karras Bryant T. , Neiman Rafael , Fritschy Daniel , Woo Savio L-Y , Daniel Dale M. 
Published: June 2007

A cadaveric model that incorporated quadriceps and hamstrings muscle loads was developed to simulate the squat exercise. The addition of hamstrings load affected knee kinematics in two ways. First, anterior tibial translation during flexion ("femoral roll-back") was significantly reduced ( P = 0.003) and second, internal tibial rotation during flexion was reduced ( P = 0.008). However, quadriceps force was unaffected by the ad dition of hamstrings load. Thus, it seems likely that hamstrings muscle activity that has been observed in vivo during a squat probably functions synergistically with the anterior cruciate ligament to provide anterior knee stability. After the ACL was sectioned, anterior tibial transla tion was significantly increased during the squat ( P = 0.04). The anterior cruciate ligament was then recon structed using a graft instrumented with a load cell. During passive motion, maximal graft tension was at full extension. During simulated squat exercise, the addition of hamstrings caused a significant decrease in graft load ( P = 0.006). During the squat, maximal graft tension was at full extension, and was equal to the graft tension at full passive extension. Thus, the squat exercise may be useful in the early stages of anterior cruciate ligament rehabilitation.
The effect of rehabilitation and return to activity on anterior-posterior knee displacements after anterior cruciate ligament reconstruction
Authors: Barber-Westin Sue D. , Noyes Frank R. 
Published: June 2007

Anterior-posterior knee displacements were measured sequentially with the KT-1000 arthrometer on 84 pa tients after anterior cruciate ligament reconstruction for chronic deficiency. We determined the correlations be tween the initial onset of abnormal displacements (greater than 2.5 mm between limbs) and time from surgery or the phase of rehabilitation. Group 1 ( N = 52) had a bone-patellar tendon-bone allograft and Group 2 ( N = 32), an iliotibial band extraar ticular procedure in addition to the allograft. The mean followup was 37 months (range, 23 to 65). At followup in Group 1, 24 patients (46%) had less than 3 mm of displacement between limbs, 22 (42%) had 3 to 5.5 mm, and 6 (12%) had greater than 5.5 mm. In Group 2, 23 patients (72%) had less than 3 mm of displacement, 8 (25%) had 3 to 5.5 mm, and 1 (3%) had greater than 5.5 mm. The difference between the groups was significant ( P < 0.05). The advanced rehabilitation program of immediate knee motion and early weightbearing, did not result in an increased incidence of abnormal displacements in the early phases. The abnormal displacements typically occurred during the latter two rehabilitation phases (intensive strength training or return to sports). Further, one-third of the abonormal displacement occurred more than 2 years postoperatively.
Effect of surgical timing on recovery and associated injuries after anterior cruciate ligament reconstruction
Authors: Wasilewski Stephen A. , Covall David J. , Cohen Sharon 
Published: June 2007

This study was undertaken to determine the optimal time after injury for arthroscopically assisted anterior cruciate ligament reconstruction using a double semi tendinosus graft. We analyzed 87 patients. Time from injury to surgery was established as acute, subacute, or chronic; the three groups were matched. Meniscal damage and treatment were categorized. Chondral le sions were graded, postoperative parameters of mo tion, strength recovery, and stability were tabulated at 3, 6, 12, and 18 months. Complications were com pared. Six percent of the patients with chronic knee injuries had two normal menisci at surgery, compared with 29% of the acute and subacute groups. Reparable tears were found in 37.8% of the knees. Chondral lesions were found in the tibiofemoral joint in 17% of acute, 7% of subacute, and 44% of the chronic knees. Postoperative motion recovery was significantly less at all time intervals for the acute group. Quadriceps strength recovery was slower in the acute knees. Sta bility was similar in all groups. Arthrofibrosis was found in 22% of acute, 0 subacute, and 12.5% of the chronic knees. Patellofemoral pain was noted in 17% of the acute, 0 of the subacute, and 9.3% of the chronic knees. This study showed that surgery done within 6 months of injury does not jeopardize the knee. Recovery after acute anterior cruciate ligament reconstruction is sig nificantly slower than after subacute or chronic recon struction.
Biomechanical considerations in patellofemoral joint rehabilitation
Authors: Steinkamp Lisa A. , Dillingham Michael F. , Markel Mark D. , Hill Jennifer A. , Kaufman Kenton R. 
Published: June 2007

Patellofemoral joint biomechanics during leg press and leg extension exercises were compared in 20 normal subjects (10 men, 10 women) aged 18 to 45 years. Knee moment, patellofemoral joint reaction force, and patellofemoral joint stress were calculated for each subject at four knee flexion angles (0°, 30°, 60°, and 90°) during leg press and leg extension exercises. All three parameters (knee moment, patellofemoral joint reaction force, and patellofemoral joint stress) were significantly greater in leg extension exercise than leg press exercise at 0° and 30° of knee flexion (P < 0.001). At 60° and 90° of knee flexion, all three param eters were significantly greater in leg press exercise than leg extension exercise (P < 0.001). Patellofemoral joint stresses for leg press and leg extension exercises intersected at 48° of knee flexion. This study demonstrates that patients with patello femoral joint arthritis may tolerate rehabilitation with leg press exercise better than with leg extension exercise in functional ranges of motion because of lower patel lofemoral joint stresses.
Prospective study of osseous, articular, and meniscal lesions in recent anterior cruciate ligament tears by magnetic resonance imaging and arthroscopy
Authors: Spindler Kurt P. , Schils Jean P. , Bergfeld John A. , Andrish Jack T. , Weiker Garron G. , Anderson Thomas E. , Piraino David W. , Richmond Bradford J. , Medendorp Sharon V. 
Published: June 2007

Fifty-four patients with anterior cruciate ligament tears that were arthroscopically reconstructed within 3 months of initial injury were prospectively evaluated. Patients with grade 3 medial collateral ligament, lateral collateral ligament, or posterior cruciate ligament tears were excluded. Eighty percent of our patients had a bone bruise present on the magnetic resonance image, with 68% in the lateral femoral condyle. Two of the latter findings—an abnormal articular cartilage signal (P = 0.02) and a thin and impacted subchondral bone (P = 0.03)—had a significant relationship with injury to the overlying articular cartilage. Meniscal tears were found in 56% of the lateral menisci and 37% of the medial menisci. A significant association was present between bone bruising on the lateral femoral condyle and the lateral tibial plateau (P = 0.02). Results of our study support the concept that the common mechanism of injury to the anterior cruciate ligament involves severe anterior subluxation with im paction of the posterior tibia on the anterior femur. Determination of the significance of bone bruising, ar ticular cartilage injury, or meniscal tears will require a long-term followup that includes evaluation for arthritis, stability, and function. These 54 patients represent the first cohort evaluated in this ongoing prospective clinical study.
Effect of anterior cruciate ligament graft tensioning direction, magnitude, and flexion angle on knee biomechanics
Authors: Gertel Theodore H. , Lew William D. , Lewis Jack L. , Stewart Nathaniel J. , Hunter Robert E. 
Published: June 2007

The objective of this study was to determine the bio mechanical effect of graft tensioning during reconstruc tion of the anterior cruciate ligament. We evaluated the magnitude of the tensioning force (22 or 67 N), the flexion angle at which the tension was applied (exten sion or 30° of flexion), and the direction of application of the tensioning force (proximal, distal, or distal with a posterior force simultaneously applied to the tibia) on 10 fresh cadaveric knees. The anterior cruciate liga ment was reconstructed using a bone-patellar tendon- bone graft. The graft was then temporarily fixed during the application of each of 12 combinations of tensioning variables listed above. After each fixation, graft force and joint motion were measured during anterior tibial loads. Tensioning direction and the flexion angle significantly affected graft force and joint motion, while the magni tude of the graft tensioning did not. Graft forces were greater when the tensioning was applied at 30° of flexion. Compared with distal tensioning with and with out posterior tibial force, graft forces with proximal tensioning were greater in extension and lower in flex ion. The position of the tibia relative to the femur was posterior and externally rotated, compared with normal, for all combinations of tensioning variables in both unloaded and anterior load states.
The strength of the central third patellar. tendon graft
Authors: Cooper Daniel E. , Deng Xianghua H. , Burstein Albert L. , Warren Russell F. 
Published: June 2007

Thirty-seven bone-patellar tendon-bone composite grafts from the knees of 21 human cadavers were tested to failure. Average donor age was 28 years. The composites were divided into 4 groups: 3 groups with 10 grafts (5 pairs) and 1 group with 7 grafts from 6 donors. In Group 1 we tested 10- versus 15-mm wide grafts that were used without twisting; Group II, 10- mm wide grafts without twisting versus 10-mm wide grafts that were twisted 90°; Group III, 10-mm wide grafts twisted 90° versus 10-mm wide grafts twisted 180°; and Group IV, 10- versus 7-mm wide grafts that were not twisted. The tests were performed using a newly described potting technique and clamp system and a servohydraulic testing machine with an elongation rate of 5 cm/sec. The results of this study suggest that the central third of the patellar tendon is stronger than previously re ported. The mean ultimate load of a 15-mm bone- patellar tendon-bone composite was 4389 N (±708); of the 10-mm wide composites, 2977 N (±516); and of the 7-mm composites, 2238 N (±316). Twisting the graft 90° increased the strength (P < 0.05). Further twisting to 180° had no significant effect compared with twisting 90°. This study supports the practice of using smaller (10 mm) bone-patellar tendon-bone grafts to avoid the potential complications of patellar fracture and graft impingement in the notch.
Effect of an Ankle Orthosis and Ankle Ligament Anesthesia on Ankle Joint Proprioception
Authors: Feuerbach Jon W. , Grabiner Mark D. , Koh Timothy J. , Weiker Garron G. 
Published: June 2007

The purposes of this study were to determine the effect of a rigid ankle orthosis (Aircast Air-Stirrup) and lateral ankle ligament anesthesia on ankle joint proprioception. Twelve noninjured subjects attempted to match nine reference ankle joint positions with their eyes closed before and after application of the ankle brace and be fore and after one or two of the lateral ankle ligaments (anterior talofibular and calcaneofibular) were anesthe tized. Three-dimensional ankle joint orientations were recorded with a Motion Analysis system. No significant differences in the constant, variable, or absolute error were seen between subjects in the non- anesthetized and anesthetized conditions (P > 0.05), regardless of whether one or two ligaments were anes thetized. Thus, it appears that ligament mechanorecep tors contributed little to ankle joint proprioception, and that the afferent feedback from skin, muscle, and other joint receptors was adequate for the positioning task of the present study. Both the variable and absolute error in matching the reference positions were significantly less with the orthosis than without (P < 0.05). Applica tion of an orthosis may increase the afferent feedback from cutaneous receptors in the foot and shank, which may in turn lead to an improved ankle joint position sense.
Use of the Suture Anchor in Open Bankart Reconstruction
Authors: Levine William N. , Richmond John C. , Donaldson William R. 
Published: June 2007

We previously reported early results of a new technique using a suture anchor to perform a modified Bankart reconstruction. That study included patients from two medical centers and had an average followup of only 1 year. This report includes patients from a single center with followup extended to a mean of 42 months (range, 33 to 61). Between April 1988 and August 1991, 53 patients with recurrent anterior glenohumeral instability underwent modified Bankart reconstruction with the use of a suture anchor. Thirty-two patients met inclusion cri teria (identifiable Bankart lesion, open repair with suture anchors, and minimum followup of 2 years); 4 patients were lost to followup. There have been no complications as a result of this technique. Ninety-three percent of the patients in the study had objectively excellent or good results. There were 2 failures with recurrent anterior dislocation. The use of a suture anchor can simplify the Bankart reconstruction. At average followup of 3 years, 26 pa tients have returned to presurgery activity levels without recurrent dislocation or subluxation. However, careful attention to anchor placement at the junction of articular cartilage and the glenoid neck is necessary to avoid technical failure.
Profiles of Exercise History and Overuse Injuries Among United States Navy Sea, Air, and Land (SEAL) Recruits
Authors: Shwayhat Alfred F. , Linenger Jerry M. , Hofherr Louise K. , Slymen Donald J. , Johnson Chrisanna Weech 
Published: June 2007

This prospective study examined running history as a risk factor for subsequent overuse injury in Navy Sea, Air, and Land (SEAL) recruits. Recruits preparing to be Navy SEALs undergo 6 months of rigorous physical training programs, which place these recruits at high risk for developing an overuse injury. We assessed the independent variables of age; prior running frequency, duration, and pace; and training surface. Univariate and multivariate estimates of risk were determined for each variable. We observed an incidence of 3.4 overuse injuries per 1000 recruit-days. Assessing the physical activity of the recruits in the 6 months before entrance into basic train ing, we found that the recruits who ran at a pace slower than 8 minutes per mile and on softer training surfaces were more likely to sustain an overuse injury during ba sic training, in both univariate and multivariate esti mates of risk. Recruits who ran fewer weekly miles and for shorter durations before basic training were also more likely to sustain an overuse injury according to univariate estimates of risk. Our findings suggest that risk of overuse injuries can be reduced by adjusting exercise routines before train ing. Running on different type surfaces with a gradual increase in speed, duration, and weekly mileage in the period preceding basic training may reduce risk of overuse injury.
Iliotibial Band Tenodesis: A New Strategy for Attachment
Authors: Draganich Louis F. , Hsieh Yeou-Fang , Reider Bruce 
Published: June 2007

We investigated the changes in distance between Gerdy's tubercle on the tibia and points on the posterior two thirds of the lateral surface of the lateral femoral condyle and adjacent lateral femoral shaft in 15 cadav eric knees. A three-dimensional digitizer was used to quantify motion of the knee during flexion ranging from full extension to 120° of flexion. Four load states were applied: internal, external, and neutral rotation, and quadriceps muscles loads based on one third of values in the literature for maximal isometric quadriceps muscles moments. The femoral location most isometric to Gerdy's tubercle was found to be strongly influenced by the load state. A 1.0 cm wide iliotibial band tenodesis was mod elled by five straight lines arising from Gerdy's tu bercle and attaching to a simulated washer at the junction of the lateral femoral condyle and shaft. Using this model and the motion data obtained from the cadavers, we investigated the effects of quadri ceps muscles loading and external rotation of the knee on changes in the distances between these tibial and femoral attachments for each of the five lines. A 180° twist modelled into the tenodesis sig nificantly reduced the range of changes in distance (difference between the largest and smallest changes in distance among the lines for a given angle of flex ion) for both of these load states. Therefore, a 180° twist in the tenodesis can enhance isometry among the fibers of the tenodesis. This implies that a 180° twist can enhance load sharing among the fibers of the tenodesis and, therefore, enhance the overall strength of the tenodesis.
Prospective Study of Pulmonary Artery Balloon Floatation Catheter Insertions
Authors: Gill John B. , Cairns John A. 
Published: June 2007

All Swan-Ganz catheter insertions over a 6-month pe riod were examined prospectively to determine current patterns of utilization, details of insertion, and the na ture, severity, and frequency of complications. There was an attempt to insert a Swan-Ganz catheter on 169 occasions in 153 patients with an eventual success rate of 95%. Catheterizations were classified as medical (82) or surgical (87). Medical patients were more acutely ill, required longer insertion time for venous cannulation (9.6 ± 7.7 min versus 8.1 ± 9.2 min; p < 0.01), needed their catheters for a longer period of time (90 ± 89 hours versus 64 ± 59 hours; p < 0.05), and had a poorer hospital survival (46% versus 86%; p < 0.05). There were no complications either during or following insertion in 45% of procedures or 50% of patients. There were 14 major complications in 8% of proce dures and 9% of patients; the most serious were com plex ventricular dysrhythmias, which accounted for the death of one patient. Most of the complications were minor and of no consequence to the patient. We con clude that Swan-Ganz catheterization, performed by a variety of operators in high-risk patients, provides reli able measurements over a long period of time with an acceptable frequency of major complications. The pulmonary artery balloon floatation catheter (Swan-Ganz catheter), which permits the measure ment of blood pressure and flow as well as mixed venous blood oxygen saturation, is widely used in the investigation and management of patients with a variety of medical and surgical illnesses accom panied by hemodynamic derangements. In seri ously ill patients, major complications might be an ticipated if medical personnel lacked the necessary skills and experience to undertake an invasive pro cedure and to employ sophisticated technology. Al though many case reports exist, there are few pro spective studies that delineate the frequency and severity of such complications. The purpose of this study was to examine pro spectively all Swan-Ganz catheter insertions in a busy community-based, acute care university teach ing hospital with housestaff. The intent was to out line current patterns of utilization and details of the insertions and, within this context, to determine the nature, severity, and frequency of complications oc curring during insertion as well as the subsequent clinical course of patients receiving Swan-Ganz catheters.
Continuing Care of Multiorgan Donor Patients
Authors: Powner David J. , Jastremski Michael , Lagler Regis G. 
Published: June 2007

Preserving the optimal function of donor organs must be the primary goal of physicians caring for patients who have been certified brain dead and from whom organs will be transplanted. During the hours before organ removal, several significant medical challenges may emerge. These challenges include restoration and maintenance of intravascular volume and cardiac output to assure adequate oxygen delivery to donor tissue; re suscitation of the patient from spontaneous cardiac ar rest ; evaluation and reversal of polyuria; management of poikilothermia and the effects of hypothermia; and treat ment of hypopituitarism and other possible changes in circulating hormones. Individual organ function and the interdependency among donor organs must be carefully monitored and balanced to assure that the recipient re ceives organs that have the best opportunity for optimal primary function. Care of the multiorgan brain dead pa tient and his or her family requires a multidisciplinary team skilled not only in the medical and surgical aspects of transplantation but also in the care of families who have suffered loss. A new focus for patient care is appropriate after the decision has been made that a patient is brain dead and will become an organ donor. Because preser vation of brain function is no longer possible, treat ment priorities should shift to maximize perfusion and function of the donor organs. Through careful management of the donor patient, the recipient will receive organs that are less likely to undergo pri mary failure. This discussion will review the physio logical support necessary to sustain brain dead pa tients and to optimize donor organ function until organ removal is completed. It is assumed that indi vidual organs will be assessed and accepted or re jected for donation using criteria established by lo cal organ procurement teams. Such criteria will not be discussed here. The brain dead organ donor presents a variety of management challenges (Table 1) that may extend over many hours while members of transplant teams and organ recipients are assembled and tis sue testing is completed. The responsibility for care may remain with the admitting physician or critical care medicine specialists, or it may be transferred to the transplant service. Coordination, however, remains the key to a successful outcome. The avail ability and interest of a knowledgeable physician to supervise the donor patient's care continues to be crucial because a variety of problems, each capable of rendering donor organs useless, may develop in the hours between brain death and organ removal.
The Third Dimension for Apparel Designers: Visual Assessment of Hat Designs for Sun Protection Using 3-D Body Scanning
Authors: Ashdown Susan P. , Slocum Ann C. , Lee Young-A 
Published: June 2007

The three-dimensional (3-D) body scanner is an imaging tool with advantages for functional apparel designers. Images of garments can help assess the function of apparel as it is worn, especially images of wearers in active positions. We evaluate 3-D body scanning as a visualization tool for designers by comparing 3-D images and printed images from a digital camera to assess benefits and limitations of 3-D images. We used images of hats worn by female golfers to assess their effectiveness for sun protection. Data were collected from six female golfers in three different stances. Multiple 2-D images (using a digital camera) and a 3-D body scan were made of each participant for comparison. As a baseline we first compared printouts from the digital camera images to printed two-dimensional (2-D) images made from the 3-D body scan data. We then compared the printouts from the digital camera to 3-D scan images as viewed and manipulated on the computer screen. Printouts from the digital camera provided better information than the 2-D printed images from the body scan data, as the printed scan images had missing areas, a comparatively lower resolution, and lacked color and texture information. However, viewing and manipulating 3-D scan images on the screen showed the relationship between the hat and the wearer clearly. The 3-D images viewed on the screen were ultimately more useful than images from the digital camera for judging the effectiveness of the hat designs.