Biomedical subjects

Joseph J Crisco

Publications and source records attributed to Joseph J Crisco.

At least 19 recordsLinked to original sources

PubMed2006

Differential expression of type X collagen in a mechanically active 3-D chondrocyte culture system: a quantitative study.

OBJECTIVE: Mechanical loading of cartilage influences chondrocyte metabolism and gene expression. The gene encoding type X collagen is expressed specifically by hypertrophic chondrocytes and up regulated during osteoarthritis. In this study we tested the hypothesis that the mechanical microenvironment resulting from higher levels of local strain in a three dimensional cell culture construct would lead to an increase in the expression of type X collagen mRNA by chondrocytes in those areas. METHODS: Hypertrophic chondrocytes were isolated from embryonic chick sterna and seeded onto rectangular Gelfoam sponges. Seeded sponges were subjected to various levels of cyclic uniaxial tensile strains at 1 Hz with the computer-controlled Bio-Stretch system. Strain distribution across the sponge was quantified by digital image analysis. After mechanical loading, sponges were cut and the end and center regions were separated according to construct strain distribution. Total RNA was extracted from the cells harvested from these regions, and real-time quantitative RT-PCR was performed to quantify mRNA levels for type X collagen and a housing-keeping gene 18S RNA. RESULTS: Chondrocytes distributed in high (9%) local strain areas produced more than two times type X collagen mRNA compared to the those under no load conditions, while chondrocytes located in low (2.5%) local strain areas had no appreciable difference in type X collagen mRNA production in comparison to non-loaded samples. Increasing local strains above 2.5%, either in the center or end regions of the sponge, resulted in increased expression of Col X mRNA by chondrocytes in that region. CONCLUSION: These findings suggest that the threshold of chondrocyte sensitivity to inducing type X collagen mRNA production is more than 2.5% local strain, and that increased local strains above the threshold results in an increase of Col X mRNA expression. Such quantitative analysis has important implications for our understanding of mechanosensitivity of cartilage and mechanical regulation of chondrocyte gene expression.

Journal Article↗

PubMed2006

Coordinate systems for the carpal bones of the wrist.

The eight small and complexly shaped carpal bones of the wrist articulate in six degrees of freedom with each other and to some extent with the radius and the metacarpals. With the increasing number and sophistication of studies of the carpus, a standardized definition for a coordinate system for each the carpal bones would aid in the reporting and comparison of findings. This paper presents a method for defining and constructing a coordinate system specific to each of the eight carpal bones based upon the inertial properties of the bone, derived from surface models constructed from three-dimensional (3-D) medical image volumes. Surface models from both wrists of 5 male and 5 female subjects were generated from CT image volumes in two neutral wrist positions (functional and clinical). An automated algorithm found the principal inertial axes and oriented them according to preset conditions in 85% of the bones, the remaining bones were corrected manually. Six of the eight carpal bones were significantly more extended in the functional neutral position than in the clinical neutral position. Gender had no significant effect on carpal bone posture in either wrist position. Correlations between the 3-D carpal posture and the commonly used 2-D clinical radiographic carpal angles are established. 3-D coordinate systems defined by the anatomy of the carpal bone, such as the ones presented here, are necessary to completely describe 3-D changes in the posture of the carpal bones.

Adult↗

PubMed2006

Carpal kinematics.

The motion of the eight carpal bones is extremely complex, and their accurate measurement has been hampered by their multiplanar rotations and translations, the irregularity of their shape, and the small magnitudes of movements. However, an accurate three-dimensional understanding of carpal motion is critical for academic and clinical purposes, and may play an important role in assessing surgical procedures or rehabilitation protocols.

Biomechanical Phenomena↗

PubMed2006

In vivo elongation of the palmar and dorsal scapholunate interosseous ligament.

PURPOSE: To investigate the elongation of the palmar and dorsal subregions of the scapholunate interosseous ligament (SLIL) in healthy human subjects throughout a complete range of wrist motion. METHODS: The 3-dimensional in vivo kinematics of the scaphoid and lunate were determined in both wrists of 13 female and 13 male volunteers from computed tomography volume images. For each wrist the palmar and dorsal insertions of the SLIL were identified on reconstructed surface models of the scaphoid and lunate. The interbone distances between the palmar and dorsal sites were calculated for the neutral wrist position. Elongations were then calculated after applying the 3-dimensional kinematics to the scaphoid and lunate. A multiple linear regression model was used to determine if elongations varied significantly as a function of wrist flexion/extension and radioulnar deviation. RESULTS: From pure wrist extension to pure wrist flexion, the fibers of the SLIL at the palmar insertion site increased significantly, from 29% shortening to 27% elongation, and the dorsal insertion decreased from 26% to 4% shortening with respect to the fiber lengths in the neutral position. From pure radial deviation to pure ulnar deviation, the elongation of the palmar insertion significantly decreased from 9% elongation to 21% shortening. There was no notable change in dorsal elongation with wrist radioulnar deviation. The multiple linear regression model predicted that there would be minimal elongation of the palmar and dorsal fibers at the wrist position along the dart thrower's path from radial extension to ulnar flexion. CONCLUSIONS: In vivo elongation of the palmar and dorsal fibers of the SLIL varied with wrist position. The palmar fibers lengthened and the dorsal fibers shortened with wrist flexion and the opposite occurred with wrist extension. Scapholunate interosseous ligament elongation was minimal as the wrist was positioned along the dart thrower's path.

Adult↗

PubMed2006

The dart-throwing motion of the wrist: is it unique to humans?

Kinematic analysis has shown a near-stationary proximal carpal row during the dart-thrower's motion, which is believed to provide a stable platform for the generation of force and accuracy during certain power and precision grip activities. This finding is consistent with evidence in the human hand of adaptations that enabled effective manipulation of stones, cylindric wood, and bone tools for throwing and clubbing. There are at least two possible explanations for the observed human proximal carpal row kinematics. One is that it is retained from a previous common ancestor with great apes and previously adapted to some form of foraging or locomotor behavior involving the hands, but was recruited for tool use after we diverged from the apes. The second is that it evolved after our divergence from apes, in synchrony with adaptations in the human hand to the manipulation of tools, and central to the development of the human's unique ability to aim and accelerate tools and weapons.

Adaptation, Physiological↗

PubMed2006

Super-resolution registration using tissue-classified distance fields.

We present a method for registering the position and orientation of bones across multiple computed-tomography (CT) volumes of the same subject. The method is subvoxel accurate, can operate on multiple bones within a set of volumes, and registers bones that have features commensurate in size to the voxel dimension. First, a geometric object model is extracted from a reference volume image. We use then unsupervised tissue classification to generate from each volume to be registered a super-resolution distance field--a scalar field that specifies, at each point, the signed distance from the point to a material boundary. The distance fields and the geometric bone model are finally used to register an object through the sequence of CT images. In the case of multiobject structures, we infer a motion-directed hierarchy from the distance-field information that allows us to register objects that are not within each other's capture region. We describe a validation framework and evaluate the new technique in contrast with grey-value registration. Results on human wrist data show average accuracy improvements of 74% over grey-value registration. The method is of interest to any intrasubject, same-modality registration applications where subvoxel accuracy is desired.

Algorithms↗

PubMed2005

Carpal bone size and scaling in men versus in women.

PURPOSE: The purpose of this study was to quantify carpal bone size, to determine whether gender influences carpal size, and to determine whether small and large carpal bones differ in size only by simple isometric scaling. METHODS: Cortical surfaces of all carpal bones in both wrists of 14 women and 14 men (ages 22-34 y) were reconstructed from computed tomography (CT) volume images. Carpal volume and bounding-box dimensions in 3 orthogonal directions were calculated and compared across genders. An average set of carpal bones were then scaled mathematically by a single factor in all directions (scaled isometrically) and compared across carpal bones of all sizes. RESULTS: Although female carpal bones were significantly smaller than male carpal bones, individual carpal volume as a percentage of the volume of the entire carpus did not differ with gender. The 3 orthogonal bounding-box dimensions of the carpal bones scaled nearly isometrically from the smallest to the largest bones. CONCLUSIONS: Across the wide range of wrist sizes studied the individual carpal volumes were a consistent percentage of carpus volume and this percentage did not differ with gender. Despite their complex shape the bounding dimensions of the carpal bones increased isometrically with increasing volume. The extensive database of dimensions provided in this study should be useful in the design and insertion of fixation systems and implants.

Adult↗

PubMed2005

Analysis of real-time head accelerations in collegiate football players.

OBJECTIVE: To measure and analyze head accelerations during American collegiate football practices and games. METHODS: A newly developed in-helmet 6-accelerometer system that transmits data via radio frequency to a sideline receiver and laptop computer system was implemented. From the data transfer of these accelerometer traces, the sideline staff has real-time data including the head acceleration, the head injury criteria value, the severity index value, and the impact location. Data are presented for instrumented players for the entire 2003 football season, including practices and games. SETTING: American collegiate football. SUBJECTS: Thirty-eight players from Virginia Tech's varsity football team. MAIN OUTCOME MEASUREMENTS: Accelerations and pathomechanics of head impacts. RESULTS: : A total of 3312 impacts were recorded over 35 practices and 10 games for 38 players. The average peak head acceleration, Gadd Severity Index, and Head Injury Criteria were 32 g +/- 25 g, 36 g +/- 91 g, and 26 g +/- 64 g, respectively. One concussive event was observed with a peak acceleration of 81 g, a 267 Gadd Severity Index, and 200 Head Injury Criteria. Because the concussion was not reported until the day after of the event, a retrospective diagnosis based on his history and clinical evaluation suggested a mild concussion. CONCLUSIONS: The primary finding of this study is that the helmet-mounted accelerometer system proved effective at collecting thousands of head impact events and providing contemporaneous head impact parameters that can be integrated with existing clinical evaluation techniques.

Acceleration↗

PubMed2005

Interpolating three-dimensional kinematic data using quaternion splines and hermite curves.

Kinematic interpolation is an important tool in biomechanics. The purpose of this work is to describe a method for interpolating three-dimensional kinematic data, minimizing error while maintaining ease of calculation. This method uses cubic quaternion and hermite interpolation to fill gaps between kinematic data points. Data sets with a small number of samples were extracted from a larger data set and used to validate the technique. Two additional types of interpolation were applied and then compared to the cubic quaternion interpolation. Displacement errors below 2% using the cubic quaternion method were achieved using 4% of the total samples, representing a decrease in error over the other algorithms.

Algorithms↗

PubMed2005

Physical and mechanical properties of various field lacrosse balls.

Although the sport of lacrosse has evolved dramatically over the last few decades and is presently the fastest growing team sport in the United States, the current specifications for balls date back to 1943. The purpose of this study was to see if various commercially available field lacrosse balls meet these specifications and to determine additional mechanical properties of the ball that may more completely characterize ball performance. Eight models from several manufacturers were tested. Seven models were designated for game play, while one model was promoted as a practice ball. In accordance with the specifications, the mass, circumference, and rebound height were recorded for one dozen balls from each model. The load required to compress the balls 0.0125 m and the coefficient of restitution (COR) with an incident speed of 26.80 m/s were also determined. We found that some balls met several of the specifications, but none of the models had every ball meet all the specifications. For the two measures of ball liveliness, rebound height had a weak correlation with COR. Ball compression loads averaged about 750 N over most models, but were almost 85% less for the practice model. It appears that current governing body specifications are outdated, as no ball model we tested met these specifications. The determination of ball liveliness at more realistic speeds should also be taken into account. Since balls with low compression loads can pass through face protectors worn by lacrosse players, the sport's governing bodies may wish to consider a specification on ball compression.

Biomechanical Phenomena↗

PubMed2005

In vivo radiocarpal kinematics and the dart thrower's motion.

BACKGROUND: Wrist motion is dependent on the complex articulations of the scaphoid and lunate at the radiocarpal joint. However, much of what is known about the radiocarpal joint is limited to the anatomically defined motions of flexion, extension, radial deviation, and ulnar deviation. The purpose of the present study was to determine the three-dimensional in vivo kinematics of the scaphoid and lunate throughout the entire range of wrist motion, with special focus on the dart thrower's wrist motion, from radial extension to ulnar flexion. METHODS: The three-dimensional kinematics of the capitate, scaphoid, and lunate were calculated from serial computed tomography scans of both wrists of fourteen healthy male subjects (average age, 25.6 years; range, twenty-two to thirty-four years) and fourteen healthy female subjects (average age, 23.6 years; range, twenty-one to twenty-eight years), which yielded data on a total of 504 distinct wrist positions. RESULTS: The scaphoid and lunate primarily flexed or extended in all directions of wrist motion, and their rotation varied linearly with the direction of wrist motion (R2= 0.90 and 0.82, respectively). Scaphoid and lunate motion was significantly less along the path of the dart thrower's motion than in any other direction of wrist motion (p < 0.01 for both carpal bones). The scaphoid and lunate translated radially (2 to 4 mm) when extended, but they did not translate appreciably when flexed. CONCLUSIONS: The dart thrower's path defined the transition between flexion and extension rotation of the scaphoid and lunate, and it identified wrist positions at which scaphoid and lunate motion approached zero. These findings indicate that this path of wrist motion confers a unique degree of radiocarpal stability and suggests that this direction, rather than the anatomical directions of wrist flexion-extension and radioulnar deviation, is the primary functional direction of the radiocarpal joint.

Adult↗

PubMed2004

Knee laxity does not vary with the menstrual cycle, before or after exercise.

BACKGROUND: An intriguing explanation for the disproportionately high rate of anterior cruciate ligament injury in female athletes is that the structural properties of the anterior cruciate ligament are affected by the menstrual hormones. Whether this actually occurs, however, is the subject of ongoing debate. HYPOTHESES: (1) Anterior cruciate ligament laxity is different in the follicular, ovulatory, and luteal phases of the menstrual cycle, and (2) exercise exacerbates the difference in anterior cruciate ligament laxity in the 3 phases. METHODS: Over the course of 10 weeks, repeated knee laxity measurements were taken on 27 high-level female athletes, before and after exercise. Point in the menstrual cycle was determined with charts of waking temperature and menstruation. The independent effects of menstrual phase and exercise were evaluated using generalized estimating equations. RESULTS: Data from 18 participants were included in the final analysis. There were no significant differences in anterior cruciate ligament laxity in any of the 3 menstrual phases, before or after exercise. CONCLUSIONS: Anterior cruciate ligament laxity is not significantly different during the follicular, ovulatory, and luteal phases of the menstrual cycle, and bicycling exercise does not exacerbate or create any differences in anterior cruciate ligament laxity.

Adult↗

PubMed2004

Preformed grafts of porcine small intestine submucosa (SIS) for bridging segmental bone defects.

Previous studies suggest that fresh, morselized porcine small intestine submucosa (SIS) may have promise in the treatment of large bone defects. This study evaluated the bone regenerative potential of preformed tubular SIS grafts, designed to provide a scaffold for regeneration of diaphyseal bone. Critical length segmental defects in the femurs of male rats were either left unfilled (n = 11) or filled with morselized cancellous bone (n = 12), or spanned with intramedullary tubes (n = 12) or periosteal sleeves (n = 12) fabricated from SIS. All of the animals were euthanized 12 weeks postoperatively. Healing was assessed with biweekly radiographs, routine histology, and mechanical testing. Copious new bone formed in the defects of all of the animals treated with cancellous bone; 10 of the 12 animals in that group had healed their defects. In contrast, no new bone was formed in the defects left unfilled or treated with SIS; only fibrous tissue was found. In both of the SIS-treated groups, the SIS persisted at twelve weeks. The cellular response to the SIS involved a mild mononuclear infiltrate in the loose or delaminated superficial layers of the tubes and sleeves, with few cells in the deeper layers. The results of this study cast doubt on the ability of SIS to support or stimulate growth of bone across a critical length segmental bone defect. Additional work will be required to determine whether our results reflect the protocols used to prepare and fabricate the SIS grafts used in the study or the inherent inability of SIS to support new bone growth.

Animals↗

PubMed2004

Metacarpophalangeal joint mechanics after 3 different silicone arthroplasties.

PURPOSE: This study was performed to compare metacarpophalangeal (MCP) joint mechanics after arthroplasty with 3 currently available silicone implants and to determine how postarthroplasty mechanics compares with the mechanics of the intact joint. METHODS: Planar 2-dimensional kinematic analysis was performed using digitized radiographs on 10 isolated fingers harvested from 5 fresh-frozen human cadavers. Radiopaque markers were affixed to the metacarpals and proximal phalanges, sewn to the flexor and extensor tendons, and placed into the stems and hinges of the implants. Each finger was tested intact, and after MCP joint replacement with 3 implants (Swanson [Wright Medical, Memphis, TN], Avanta [Avanta Orthopaedics, San Diego, CA], and NeuFlex [DePuy Orthopaedics, Warsaw, IN]). The fingers were secured to the test fixture and the flexor digitorum profundus flexor and extensor tendons were loaded with physiologic weights. Lateral radiographs were taken at approximately 10 degrees intervals and were digitized on a high-resolution scanner. Instantaneous center of rotation (ICR), tendon excursion, and tendon moment arm were calculated. Statistical analysis was performed using repeated measures one-way analysis of variance and Dunnett post tests. RESULTS: The ICRs of the intact and implanted MCPs did not follow a smooth path. The variability of the ICRs of the intact MCP joints was 2.1 +/- 0.8 mm. The variations in the Avanta and DePuy implants were similar (3.1 +/- 1.0 mm and 3.5 +/- 1.5 mm, respectively), whereas the Swanson implant was higher (4.9 +/- 1.7 mm). Implant pistoning was most pronounced with the Swanson implant, which moved 2.40 +/- 0.97 mm over the full range of motion. The Avanta and DePuy implants pistoned significantly less than the Swanson implant (1.05 +/- 0.45 mm and 0.69 +/- 0.31 mm, respectively). Flexor tendon excursion was greater for the intact joint when compared with all 3 implants while extensor tendon excursion was similar for all. Flexor tendon moment arm was similar for the intact joint and the Avanta and NeuFlex implants whereas the Swanson implant was reduced significantly; extensor tendon moment arms were similar for all. CONCLUSIONS: The ICR of the NeuFlex implant most closely matched that of the intact MCP joint. The Swanson implant had greater pistoning and dorsal-volar translation when compared with the intact joint and the Avanta and NeuFlex implants. The block-hinge type design of the Avanta and NeuFlex implants improved tendon moment arm overall when compared with the Swanson, likely imparting greater functional ability for finger motion. Overall the NeuFlex implant most closely matched the ICR, tendon excursion, and moment arm when compared with the intact native MCP joint.

Aged↗

PubMed2004

Estimating joint contact areas and ligament lengths from bone kinematics and surfaces.

We present a novel method for modeling contact areas and ligament lengths in articulations. Our approach uses volume images generated by computed tomography and allows the in vivo and noninvasive study of articulations. In our method, bones are modeled both implicitly (scalar distance fields) and parametrically (manifold surfaces). Using this double representation, we compute interbone distances and estimate joint contact areas. Using the same types of representation, we model ligament paths; in our model, the ligaments are approximated by the shortest paths in a three-dimensional space with bone obstacles. We demonstrate the method by applying our contact area and ligament model to the distal radioulnar joints of a volunteer diagnosed with malunited distal radius fracture in one forearm. Our approach highlights focal changes in the articulation at the distal radioulnar joint (location and area of bone contact) and potential soft-tissue constraints (increased "length" of the distal ligaments and ligament-bone impingement in the injured forearm). Results suggest that the method could be useful in the study of normal and injured anatomy and kinematics of complex joints.

Algorithms↗

PubMed2004

An algorithm for estimating acceleration magnitude and impact location using multiple nonorthogonal single-axis accelerometers.

Accelerations of the head are the likely cause of concussion injury, but identifying the specific etiology of concussion has been difficult due to the lack of a valid animal or computer model. Contact sports, in which concussions are a rising health care concern, offer a unique research laboratory environment. However, measuring head acceleration in the field has many challenges including the need for large population sampling because of the relatively low incidence of concussions. We report a novel approach for calculating linear acceleration that can be incorporated into a head-mounted system for on-field use during contact sports. The advantages of this approach include the use of single-axis linear accelerometers, which reduce costs, and a nonorthogonal arrangement of the accelerometers, which simplifies the design criteria for a head-mounted and helmet compatible system. The purpose of this study was to describe the algorithm and evaluate its accuracy for measuring linear acceleration magnitude and impact location using computer simulation and experimental tests with various accelerometer configurations. A 10% error in magnitude and a 10 deg error in impact location were achieved using as few as six single-axis accelerometers mounted on a hemispherical headform.

Acceleration↗

PubMed2003

Carpal bone postures and motions are abnormal in both wrists of patients with unilateral scapholunate interosseous ligament tears.

PURPOSE: The recent ability to measure 3-dimensional in vivo carpal kinematics has facilitated the noninvasive study of complex carpal bone motion. METHODS: In this study we examined the flexion/extension carpal kinematics of both wrists in 8 patients with unilateral scapholunate interosseous ligament (SLIL) tears by using computed tomographic (CT) imaging and a markerless bone registration technique. Carpal bone neutral posture and flexion/extension motion of both wrists of the injured patients were compared with the same parameters in wrists of 10 uninjured male and female volunteers (normals). RESULTS: The neutral posture of the injured scaphoid and lunate were significantly more extended than those of normals. In these patients, however, the postures of the scaphoid and lunate in the contralateral uninjured wrists also were abnormal and were similar to those of the injured wrist. In addition, extension of the lunate and flexion of the scaphoid in both the injured and uninjured wrist were significantly different from normal but not different from each other. CONCLUSIONS: This study was unable to attribute altered carpal posture and motion to SLIL tears because abnormalities were found in both wrists of patients with unilateral injury. The etiology of abnormal wrist kinematics in the asymptomatic wrist of patients with unilateral tears of the scapholunate ligament is not known.

Adult↗

PubMed2003

Physiologic weight-bearing increases new vessel formation during distraction osteogenesis: a micro-tomographic imaging study.

During distraction osteogenesis, large volumes of new bone are formed through the slow distraction of fracture callus. The newly formed bone is closely linked to angiogenesis and positively influenced by physiologic loading. In this study, a rat model was used to explore the correlation between these two observations. Unilateral femoral lengthenings were performed in 18 male Sprague-Dawley rats (400-500 g, age<6 months). Half of the animals were allowed to bear weight freely (WB) while the remaining animals were made non-weight-bearing via a through-knee amputation (NWB). After a seven-day latency period, femurs were lengthened 7 mm over 21 days. Animals were sacrificed at 7, 21, 35, and 49 days (0, 4.7, 7, and 7 mm of distraction) at which time lower extremity vessels were perfused with a 60% (w/v) barium sulfate suspension. High-resolution three-dimensional images of the vascular architecture were generated using a fan-beam micro-tomography machine by digitally separating the contrast-filled vessels from surrounding tissue. For two subvolumes, VOI(1), which included vessels in the medullary canal, cortex, and periosteum, and VOI(2), which included only vessels in the canal and cortex, the total tissue volume (TV), the volume of vessels (VV), and vessel diameter (VD) were determined. For the larger subvolume (VOI(1)), VV and vessel density (VV/TV) increased as a function of time (p<0.001) in WB animals. In NWB animals, VV increased significantly with time (p=0.029), while VV/TV did not (p=0.36). Increases in VV and VV/TV were significantly greater in WB animals than in NWB animals (p<0.01 and 0.05, respectively). VD was similar in both groups and did not change with time. Our data suggest that weight bearing stimulates new vessel formation during distraction osteogenesis.

Animals↗