1/40. Distal disinsertion of the patellar ligament combined with avulsion fractures at the medial and lateral margins of the patella. A case report and an experimental study.A 12-year-old boy presented with a proximally retracted patella 5 months after an injury to the left knee. The clinical and radiographic features and the findings at operation led to the conclusion that the original lesion had been a distal disinsertion of the patellar ligament combined with avulsion fractures at the medial and lateral margins of the patella, produced by the medial and lateral longitudinal patellar retinacula. Loading experiments on amputation and cadaver specimens showed that these retinacula, apart from being tendons for the vastus medialis and the vastus lateralis, respectively, constitute a direct fibrous connection of considerable strength between the patella and the tibia and thus are capable of producing avulsion fractures.- - - - - - - - - - ranking = 1keywords = fracture (Clic here for more details about this article) |
2/40. External rotation-lateral view of the ankle in the assessment of the posterior malleolus.Demonstration of a posterior malleolar fragment on a radiograph of an ankle fracture is important in the diagnosis and evaluation of posterior malleolus fractures. The size and extent of displacement of a posterior malleolar fragment can be evaluated. The diagnosis of non-union of the posterior malleolus is also important because it can lead to failure of reduction of ankle fractures. The authors present a case in which nonunion of the posterior malleolus was diagnosed by an external-rotation lateral view of the ankle. This could not be demonstrated on the AP or the lateral views. Thirteen cadaver feet were then used to study the external-rotation lateral view. A posterior malleolar fracture was created, and the borders of the fracture line were marked with solder wire. The average external rotation angle required to best demonstrate the posterior malleolar fracture was 50 degrees (range, 43 degrees -55 degrees). The actual size of the posterior malleolus fragment was measured and compared to the x-ray measurement. There was a 0.10 correction for the determination of the actual size of the fragment. The unmarked fragment could not be demonstrated on AP and lateral views.- - - - - - - - - - ranking = 1keywords = fracture (Clic here for more details about this article) |
3/40. Mechanisms of orbital floor fractures: a clinical, experimental, and theoretical study.PURPOSE: The purpose of this study was to investigate the two accepted mechanisms of the orbital blow-out fracture (the hydraulic and the buckling theories) from a clinical, experimental, and theoretical standpoint. methods: Clinical cases in which blow-out fractures resulted from both a pure hydraulic mechanism and a pure buckling mechanism are presented. Twenty-one intact orbital floors were obtained from human cadavers. A metal rod was dropped, experimentally, onto each specimen until a fracture was produced, and the energy required in each instance was calculated. A biomathematical model of the human bony orbit, depicted as a thin-walled truncated conical shell, was devised. Two previously published (by the National Aeronautics Space Administration) theoretical structural engineering formulas for the fracture of thin-walled truncated conical shells were used to predict the energy required to fracture the bone of the orbital floor via the hydraulic and buckling mechanisms. RESULTS: Experimentally, the mean energy required to fracture the bone of the human cadaver orbital floor directly was 78 millijoules (mj) (range, 29-127 mj). Using the engineering formula for the hydraulic theory, the predicted theoretical energy is 71 mj (range, 38-120 mj); for the buckling theory, the predicted theoretical energy is 68 mj (range, 40-106 mj). CONCLUSION: Through this study, we have experimentally determined the amount of energy required to fracture the bone of the human orbital floor directly and have provided support for each mechanism of the orbital blow-out fracture from a clinical and theoretical basis.- - - - - - - - - - ranking = 2keywords = fracture (Clic here for more details about this article) |
4/40. Intraoperative imaging of the tibial plafond fracture: a potential pitfall.STUDY DESIGN: Human tibial plafond cadaveric specimens were coronally sectioned and imaged to assess the accuracy of evaluation of ankle joint line congruity using anteroposterior radiography. Two interesting representative clinical cases are discussed. OBJECTIVES: To evaluate the validity of the routine use of anteroposterior radiographs to evaluate intra-operative ankle joint line congruity in circumstances where lateral radiographs are infeasible due to obscuring internal or external hardware. methods: Eleven frozen human cadaveric lower extremity specimens were used in this study. At the level of the tibial plafond, the specimens were sequentially sliced into 0.5cm sections in the coronal plane. True anteroposterior radiographs were taken with the specimen en bloc. Sequentially, the posterior slices were removed one by one, with an image taken after removing each section. The process was then repeated by removing the anterior sections sequentially with intervening radiographs. Each series of anteroposterior radiographs was then evaluated to characterize which portion of the joint line on the whole specimen view had been contributed by each of the sections. This then allowed us to make inferences about the evaluation of the joint line if it had been derived solely by anteroposterior radiography. Two poignant clinical cases demonstrating the clinical relevance of this information are discussed. RESULTS: By sequentially imaging after removing coronal sections of the tibial plafond we were able to accurately characterize the contribution of each portion of the plafond to the overall anteroposterior view. By primarily imaging the anterior portions of the plafond, with the posterior portions removed, the joint line image was virtually unchanged from the en bloc anteroposterior radiograph. However, removal of the anterior coronal sections caused large variation in the joint line image. These observations demonstrate that the anteroposterior radiograph of the tibial plafond characterizes the anterior portion of the joint well, while it represents a poor assessment of the posterior portion of the joint. This was well illustrated in our clinical case presentations. CONCLUSION: In severe fractures of the tibial plafond multiple forms of internal and external devices are frequently used for fixation. In these circumstances hardware may obscure the lateral view making it impossible to obtain adequate lateral radiographs to assess fracture reduction and joint line congruity. In this scenario, the anteroposterior radiograph is frequently relied upon to confirm the anatomic relationship of the displaced fragments. However, this view fails to accurately characterize reduction in the entire joint line and, intra-operatively, may mislead the surgeon to accept a reduction as anatomic when intra-articular incongruity still exists. Strict attention to pre-operative radiographs and the use of additional rotated views may aid the surgeon in this setting to assess fracture reduction and joint line congruence.- - - - - - - - - - ranking = 1.1666666666667keywords = fracture (Clic here for more details about this article) |
5/40. Secondary fractures of Le Fort I osteotomy.PURPOSE: To report the ophthalmic complications of Le Fort I osteotomy for the correction of dentofacial deformities and to determine the maximal compressive loads applied during pterygomaxillary separation in a cadaver model. methods: Two cases of ophthalmic complications arising after Le Fort I osteotomy are reported. Le Fort I osteotomy was performed on five cadavers. The maximal compressive load applied during pterygomaxillary separation was recorded with a 10 kN (3,000 lbf) load cell of a MTS Mini-Bionix servo-hydraulic machine (MTS, Eden Prairie, MN, U.S.A.). A paired t test was used to compare forces applied to the right and left sides. Computed tomography scans of each specimen were obtained after Le Fort I osteotomy to document secondary fractures. The skulls were subsequently stained with 1% fuschin red to highlight secondary fractures. RESULTS: Maximum compressive loads during pterygomaxillary separation ranged from 22 N (5.0 lbf) to 162 N (36.5 lbf), with an average of 106 N (23.8 lbf) (SD 47.6 N [10.7 lbf]). Forces applied on the first operative side were significantly greater than forces applied on the second operative side (p = 0.0034). Secondary fractures were found in three specimens by computed tomography and in two specimens by 1% fuschin red. All secondary fractures occurred on the second operative side. CONCLUSION: Secondary fractures in the Le Fort I osteotomy procedures occurred on the side opposite the greater maximal compressive load and on the second operative side.- - - - - - - - - - ranking = 1.5keywords = fracture (Clic here for more details about this article) |
6/40. Intranasal endoscopy-assisted repair of medial orbital wall fractures.The repair of medial orbital blow-out fractures remains a challenging surgical procedure for most surgeons. Endoscopic intranasal visualization of the medial orbital wall or lamina papyracea is a technique familiar to most otolaryngologists. This endoscopic view would allow for confirmation of orbital content reduction and bimanual manipulation of an orbital implant. To determine the effectiveness of a new surgical technique, a cadaveric study was performed to evaluate the ability to (1) reduce the herniated orbital contents and (2) restore the normal anatomic orbital configuration and volume with the addition of an orbital implant. Excellent visualization of the fracture was achieved in all cadaveric specimens. In addition, endoscopic intranasal visualization of the medial orbital wall greatly facilitated the anatomic reduction of orbital contents and proper placement of the orbital implant. The surgical technique is described and a clinical case is reported in which this endoscopic technique was effectively used. Arch Facial Plast Surg. 2000;2:269-273- - - - - - - - - - ranking = 1keywords = fracture (Clic here for more details about this article) |
7/40. Diastasis with low distal fibula fractures: an anatomic rationale.Tibiofibular diastasis occurs infrequently in displaced ankle fractures that include a low fibula fracture. This is because the interosseous ligament, the major ligament resisting diastasis, lies above the level of the fracture. The anatomic study of the syndesmotic complex of the ankle reported here showed that the interosseous ligament has a variable attachment on the fibula, differing between specimens in its distance above the synovial reflection or joint line. Although most specimens had attachments approximately 1 cm or greater above the joint line, one of 18 specimens attached just above the synovial reflection. In such a case, a low fibula fracture would disrupt the interosseous ligament, which explains the anatomic basis for the infrequent diastasis in these ankle fractures.- - - - - - - - - - ranking = 1.5keywords = fracture (Clic here for more details about this article) |
8/40. Cadaveric study of blood supply to the lower intraorbital fat: etiologic relevance to the complication of anaerobic cellulitis in orbital floor fracture.BACKGROUND AND PURPOSE: Although orbital fractures are common, orbital cellulitis rarely develops following orbital fracture. We hypothesized that compromise of the blood supply to the intraorbital fat during orbital floor fracture is responsible for this condition. The purpose of this study was to determine whether or not the lower intraorbital fat is supplied by a branch of the infraorbital artery along the orbital groove or canal on the orbital floor. MATERIALS AND methods: We dissected 14 orbits from seven fixed human cadavers and 12 orbits from six fresh cadaver heads following dye injection into the maxillary artery. The sites of dye-filled vessels branching from the infraorbital artery supplying the lower intraorbital fat were measured and plotted on a two-dimensional orbital floor graph. RESULTS: A main branch of the infraorbital artery rose through the medial orbital floor to supply the lower intraorbital fat in all of the cadaver orbits. The sites of the branching point of the vessel ranged from 0 to 5 mm (mean, 2.2 mm; n = 14) medial to the line connecting the infraorbital foramen and the infraorbital groove. The shortest distance measured from the branching point to the orbital rim ranged from 3 to 20 mm (mean, 14.1 mm; n = 14). This suggests that if orbital fracture were to occur around the infraorbital groove or canal, this vascular pedicle would be in danger of being incarcerated by bone fragments. CONCLUSION: Our cadaveric investigation revealed that the lower intraorbital fat is supplied by a branch of the infraorbital artery along the infraorbital groove or canal on the orbital floor. This finding suggests that compromised blood supply to the intraorbital fat may cause anaerobic cellulitis or enophthalmos.- - - - - - - - - - ranking = 1.3333333333333keywords = fracture (Clic here for more details about this article) |
9/40. A trigeminal neuralgia-like paroxysmal pain condition presumably due to buccal nerve compression in the temporalis muscle.We encountered three patients with trigeminal neuralgia-like paroxysmal pain in the buccal nerve region. In all cases, paroxysmal pain was felt spreading to the receptive field of the ipsilateral buccal nerve, and clear tenderness was observed during intraoral palpation at the inner side of the mandibular ramus where the temporalis muscle runs and attaches. It was assumed that the paroxysmal pain might be caused by nerve compression related to temporalis muscle hyperactivity. To lend support to this hypothesis, we also studied the anatomical relationship between the buccal nerve and the masticatory muscles. In this autopsy study, the buccal nerve pierced the temporalis muscle in six (12%) of 52 specimens from 26 cadavers. These findings support the hypothesis that peripheral buccal nerve compression could be an etiology of paroxysmal neuropathic pain in the unilateral orofacial region.- - - - - - - - - - ranking = 0.12088769331262keywords = compression (Clic here for more details about this article) |
10/40. Extraforaminal entrapment of the fifth lumbar spinal nerve by osteophytes of the lumbosacral spine: anatomic study and a report of four cases.STUDY DESIGN: An anatomic study of the associations between the fifth lumbar spinal nerve (L5 spinal nerve) and a lumbosacral tunnel, consisting of the fifth lumbar vertebral body (L5 vertebral body), the lumbosacral ligament, and sacral ala, and clinical case reports of four patients with lumbar radiculopathy secondary to entrapment of the L5 spinal nerve in the lumbosacral tunnel. OBJECTIVES: To delineate the anatomic, clinical, and radiologic features and surgical outcome of patients with entrapment of the L5 spinal nerve in the lumbosacral tunnel. SUMMARY OF BACKGROUND DATA: Although several cadaveric studies on a lumbosacral tunnel as a possible cause of L5 radiculopathy have been reported, few studies had focused on osteophytes of the L5-S1 vertebral bodies as the major component of this compressive lesion, and clinical reports on patients with this disease have been rare. methods: Lumbosacral spines from 29 geriatric cadavers were examined with special attention to the associations between osteophytes of the L5-S1 vertebral bodies and the L5 spinal nerve. Four patients with a diagnosis of the entrapment of the L5 spinal nerve by osteophytes at the lumbosacral tunnel were treated surgically, and their clinical manifestations and surgical results were reviewed retrospectively. RESULTS: The anatomic study demonstrated osteophytes of the L5-S1 vertebral bodies in seven of the 29 cadavers. Entrapment of the L5 spinal nerve in the lumbosacral tunnel was observed in six of the seven cadavers with L5-S1 osteophytes but in only one of the 22 cadavers without such osteophytes (P < 0.05, chi2 test). All four patients had neurologic deficits in the L5 nerve root distribution. MRI and myelography showed no abnormal findings in the spinal canal, but CAT scans demonstrated prominent osteophytes on the lateral margins of L5-S1 vertebral bodies in all four. Selective L5 nerve block completely relieved all patients of pain but only temporarily. Three patients were treated via a posterior approach by resecting the sacral ala along the L5 spinal nerve, and the other patient was treated by laparoscopic anterior resection of the osteophytes. pain relief was obtained in the four patients immediately after surgery, but one patient experienced recurrence of pain 1 year after the first surgery and was successfully treated by additional posterior decompression and fusion. CONCLUSIONS: Extraforaminal entrapment of L5 spinal nerve in the lumbosacral tunnel can cause L5 radiculopathy, and osteophytes of L5-S1 vertebral bodies are a major cause of the entrapment.- - - - - - - - - - ranking = 0.020147948885437keywords = compression (Clic here for more details about this article) |
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