Cases reported "Cadaver"

Filter by keywords:



Filtering documents. Please wait...

1/4. A keyhole approach for endoscopically assisted pedicle screw fixation in lumbar spine instability.

    OBJECTIVE: The standard approach for dorsal transpedicular fixation in lumbar spine instability requires extensive exposure of the vertebral column. This increases the risk of potential complications and possibly destabilizes healthy neighboring segments because of the dissection and denervation of paravertebral muscles. The majority of spinal disorders are currently treated successfully via limited and tailored approaches. Accordingly, a keyhole approach for dorsal fusion of the lumbar spine was developed on the basis of an anatomic study. methods: The new endoscopic technique entails the transmuscular insertion of a pedicle screw-rod fixation device via a rigid operating sheath. As a prerequisite, the endoscopic microanatomy of the target area, as visible through the operating sheath, was first evaluated on lumbar bone specimens. To localize the exact screw entry point into the pedicle, we identified the bony and ligamentous landmarks on partly macerated specimens. To determine the course of the pedicle screws, we deduced the corresponding angles of convergence from transparent polyester casting models of average vertebrae from T12 to S1. These angles were transferred into the operative situation and measured on-line with an inclinometer. The approach was finally tested on 12 cadavers for clinical feasibility and accuracy of screw placement and then successfully implemented in patients. RESULTS: After extracutaneous localization of the pedicles at lateral fluoroscopy, paramedian skin incisions were made above the pedicles of the motion segment to be stabilized. The operative windows were exposed by use of a rigid operating sheath (length, 50 mm; diameter, 15 mm), which was inserted transmuscularly in the pedicle axis. The screw entry point into the pedicles was localized by endoscopic dissection of the mamilloaccessory ligament, bridging the mamilloaccessory notch. The pilot holes were created via insertion of a blunt-tipped pedicle probe. The adequate angles of convergence were constantly controlled during hollowing of the pedicles by an inclinometer mounted to the pedicle probe handle. The pedicle screws were then inserted through the operating sheaths. After removal of the operating sheaths, the connecting rods were inserted transmuscularly and anchored in the pedicle screw heads. Posterior bone grafting was performed after completion of the dorsal instrumentation. The dorsal fusion site was exposed by reinserting the operating sheath and tilting it medially. CONCLUSION: This new approach significantly reduces surgical traumatization and destabilization of adjacent motion segments. An endoscopic operating sheath, adopted from thoracoscopic surgery, creates space for visualization and surgical manipulations. The newly defined anatomic landmarks provide guidance to the screw entry point into the pedicle in the center of the exposure. observation of the exact corresponding angles of convergence during screw insertion by an inclinometer facilitates correct screw placement. In accordance with the initial anatomic studies, this approach was successfully performed on 12 cadavers and then used in six patients. Two illustrative cases are presented.
- - - - - - - - - -
ranking = 1
keywords = motion
(Clic here for more details about this article)

2/4. Avascular necrosis of the hamate: a case report with reference to the hamate blood supply.

    Avascular necrosis of the hamate bone has not previously been reported. In this case the proximal fragment of the fractured hamate underwent avascular necrosis and prolonged healing. In an attempt to explain this sequela, angiography of the cadaver carpus followed by dissection of intact wrists and a study of enzyme-cleaned hamates showed that their wedge-shaped proximal segments were mostly enveloped by a distal extension of the midcarpal joint cavity and thus totally dependent on intraosseous nutrition. Consequently, the segment is at risk when a fracture line transects the body proximal to the base of the wedge. Clinically, this condition resulted in persistent discomfort and limitations of motion. A postinjury bone scan of the wrist indicated avascular changes in the proximal third of the hamate, and a delayed union was followed by later revascularization and a more normal scan image.
- - - - - - - - - -
ranking = 0.5
keywords = motion
(Clic here for more details about this article)

3/4. Biomechanical evaluation of the stability of thoracolumbar burst fractures.

    STUDY DESIGN. The decision to treat thoracolumbar burst fractures in neurologically intact patients either surgically or nonoperatively depends largely on whether the fracture is clinically stable. This study evaluated the relative contributions of the anterior, middle, and posterior columns to spinal stability by way of in vitro experimentation and supplemental analysis of patients with nonoperatively treated burst fractures. methods. An L1 burst fracture model was used to evaluate the contribution of the three columns of the spine to resisting imposed flexion deforming forces. Six spines were tested to a gross bending flexion angle of 25 degrees. Changes in vertebral motion across the site of injury were measured and compared. In addition, a summary of our recent clinical experience with nonoperatively treated burst fractures is presented and correlated with the study's laboratory findings. RESULTS. T12-L2 motion measurements after vertebral and ligamentous disruption revealed a statistically significant increase in motion upon anterior and added posterior column compromise, but not for added middle column disruption. review of the clinical series revealed that burst fractures with anterior and middle column compromise but an intact posterior column were stable and healed satisfactorily. CONCLUSIONS. The data suggest that the condition of the posterior column, not the middle column, is a better indicator of burst fracture stability. It is proposed that the classic burst fracture (anterior and middle column compromise) is a stable injury that, in the absence of neurologic deficit, can be managed nonoperatively.
- - - - - - - - - -
ranking = 1.5
keywords = motion
(Clic here for more details about this article)

4/4. The use of a permanent dermal allograft in full-thickness burns of the hand and foot: a report of three cases.

    The standard method of grafting deep, thermal hand-and-foot burns with either full-thickness sheet grafts or narrowly meshed, thick, split-thickness skin grafts not only leaves a deep donor site, but also becomes complicated by infection, hypertrophic scarring, blistering, and hyper- or hypopigmentation. The availability now of an acellular, immunologically inert dermal transplant (AlloDerm; LifeCell Corp., The Woodlands, texas) allows the successful use of ultrathin autografts while maximizing the amount of dermis delivered to the wound site. These autografts leave thin donor sites that heal faster and with fewer complications. This case report describes the use of AlloDerm dermal grafts on three patients with full-thickness burns of the distal extremities. Grafts were applied to the hand in two cases and the dorsum of the foot in the third. Range of motion, grip strength, fine motor coordination, and functional performance were quantitatively evaluated. As demonstrated by these patients, cosmetic and functional results were considered good to excellent after the use of AlloDerm grafts with thin autografts.
- - - - - - - - - -
ranking = 0.5
keywords = motion
(Clic here for more details about this article)


Leave a message about 'Cadaver'


We do not evaluate or guarantee the accuracy of any content in this site. Click here for the full disclaimer.