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4.
Bone Joint J ; 100-B(10): 1359-1363, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30295529

ABSTRACT

AIMS: This study reports the outcomes of a technique of soft-tissue coverage and Chopart amputation for severe crush injuries of the forefoot. PATIENTS AND METHODS: Between January 2012 to December 2016, 12 patients (nine male; three female, mean age 38.58 years; 26 to 55) with severe foot crush injury underwent treatment in our institute. All patients were followed-up for at least one year. Their medical records, imaging, visual analogue scale score, walking ability, complications, and functional outcomes one year postoperatively based on the American Orthopedic Foot and Ankle Society (AOFAS) and 36-Item Short-Form Health Survey (SF-36) scores were reviewed. RESULTS: The mean length of follow-up was 18.6 months (13 to 28). Two patients had a local infection, flap necrosis was seen in one patient, and one patient experienced a skin graft wound healing delay. Of the 12 patients, one had persistent infection and eventually required below-knee amputation, but pain-free walking was achieved in all the other patients. The mean one-year postoperative AOFAS and SF-36 scores were 75.6 (68 to 80) and 82 (74 to 88), respectively. CONCLUSION: Although our sample size was small, we believe that this treatment method may be a valuable alternative for treating severe foot crush injuries. Cite this article: Bone Joint J 2018;100-B:1359-63.


Subject(s)
Amputation, Surgical/methods , Ankle Joint/surgery , Arthrodesis/methods , Foot Injuries/surgery , Free Tissue Flaps/transplantation , Adult , Female , Follow-Up Studies , Humans , Male , Middle Aged , Plastic Surgery Procedures , Retrospective Studies , Treatment Outcome
5.
Bone Joint Res ; 6(4): 253-258, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28450318

ABSTRACT

OBJECTIVES: Osteoarthritis (OA) is the most common form of arthritis, affecting approximately 15% of the human population. Recently, increased concentration of nitric oxide in serum and synovial fluid in patients with OA has been observed. However, the exact role of nitric oxide in the initiation of OA has not been elucidated. The aim of the present study was to investigate the role of nitric oxide in innate immune regulation during OA initiation in rats. METHODS: Rat OA was induced by performing meniscectomy surgery while cartilage samples were collected 0, 7, and 14 days after surgery. Cartilage cytokine levels were determined by using enzyme-linked immunosorbent assay, while other proteins were assessed by using Western blot RESULTS: In the time course of the study, nitric oxide was increased seven and 14 days after OA induction. Pro-inflammatory cytokines including tumour necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 were decreased. L-NG-Nitroarginine methyl ester (L-NAME, a non-specific nitric oxide synthase inhibitor) significantly decreased cartilage nitric oxide and blocked immune suppression. Further, L-NAME decreased Matrix metalloproteinase (MMPs) and increased tissue inhibitor of metalloproteinase (TIMP) expression in meniscectomised rats. CONCLUSION: Nitric oxide-dependent innate immune suppression protects cartilage from damage in the early stages of OA initiation in rats.Cite this article: C-C. Hsu, C-L. Lin, I-M. Jou, P-H. Wang, J-S. Lee. The protective role of nitric oxide-dependent innate immunosuppression in the early stage of cartilage damage in rats: Role of nitric oxide in ca rtilage da mage. Bone Joint Res 2017;6:253-258. DOI: 10.1302/2046-3758.64.BJJ-2016-0161.R1.

6.
Ultraschall Med ; 37(1): 56-62, 2016 Feb.
Article in English | MEDLINE | ID: mdl-25389914

ABSTRACT

PURPOSE: We evaluated the effects of ultrasound (US)-guided percutaneous radiofrequency thermal lesioning (RTL) and the impact of obesity when treating patients with recalcitrant plantar fasciitis. MATERIALS AND METHODS: 30 consecutive patients were enrolled. The visual analog scale (VAS), American Orthopedic Foot-Ankle Society (AOFAS) Ankle-Hindfoot Score, and plantar fascia thickness measured using US were recorded at baseline and at follow-up 1, 3, 6, and 12 months after surgery under local anesthesia. RESULTS: 12 patients in the obese (BMI ≥ 30 kg/m(2)) group and 18 patients in the non-obese group. There were significant postoperative decreases in VAS scores and in fascial thickness, and an increase in the AOFAS scores (all p < 0.001). The obese group showed delayed pain and functional improvement within the first 3 months after the index procedure (p < 0.01). Significant pain reduction and functional improvement were apparent earlier (after 1 month, p < 0.001) in the non-obese group than in the obese group (after 3 months, p < 0.05). Fascia thickness was positively correlated with the VAS score and negatively correlated with the AOFAS score (both p < 0.001). CONCLUSION: US should be regarded as a useful objective tool to guide RTL and to monitor the effectiveness of treatment. US-guided percutaneous RTL for recalcitrant PF is a minimally invasive treatment option that yields satisfactory results. Therefore, it should at least be considered before using more invasive procedures. Moreover, obesity leads to delayed improvement but does not affect overall outcome after 12 months. Plantar fascial thickness was correlated with VAS and AOFAS scores.


Subject(s)
Fasciitis, Plantar/surgery , Ultrasonography, Interventional/methods , Equipment Design/instrumentation , Fascia/diagnostic imaging , Fasciitis, Plantar/diagnostic imaging , Female , Follow-Up Studies , Humans , Male , Middle Aged , Obesity/complications , Recurrence , Statistics as Topic , Ultrasonography, Interventional/instrumentation , Visual Analog Scale
7.
Osteoarthritis Cartilage ; 20(12): 1507-13, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22944523

ABSTRACT

OBJECTIVES: To investigate the association of ultrasound (US) features with pain and the functional scores in patients with equal radiographic grades of osteoarthritis (OA) in both knees. METHODS: Fifty-six consecutive patients with knee OA: 85 symptomatic knees (81 knees with medial pain) and 27 asymptomatic knees, and 10 healthy patients without knee OA as a control were enrolled. US was done by two ultrasonographers blinded to patient diagnoses. US features were semiquantitatively scored (0-3) when appropriate. RESULTS: In the OA group, common US findings were marginal osteophyte, suprapatellar synovitis, suprapatellar effusion (SPE), medial meniscus protrusion, medial compartment synovitis (MCS), lateral compartment synovitis, and Baker's cyst. Only SPE and MCS were significantly associated with knee pain. Visual analog pain scale (VAS) scores on motion were positively linearly associated with SPE and MCS (P < 0.01). Only MCS was degree-dependently associated with VAS scores at rest, the Western Ontario and McMaster Universities pain subscale, and the presence of medial knee pain (P < 0.01) after adjustments for age, gender, body mass index (BMI), radiographic grade, and other US features. In the control group, no US features were associated with knee pain. CONCLUSIONS: US inflammation features, including SPE and MCS, were positively linearly associated with knee pain in motion. MCS was also degree-dependently associated with pain at rest and the presence of medial knee pain. These findings show that synovitis was one important predictive factor of pain. Further studies to confirm the association of US features and pain are warranted.


Subject(s)
Knee Joint/diagnostic imaging , Osteoarthritis, Knee/complications , Pain Measurement/methods , Pain/etiology , Adult , Female , Follow-Up Studies , Humans , Knee Joint/physiopathology , Male , Middle Aged , Osteoarthritis, Knee/diagnosis , Osteoarthritis, Knee/physiopathology , Pain/diagnosis , Pain/physiopathology , Radiography , Range of Motion, Articular , Retrospective Studies , Severity of Illness Index , Ultrasonography
8.
Osteoarthritis Cartilage ; 19(6): 728-36, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21376128

ABSTRACT

OBJECTIVE: Immune cells are involved in the pathogenesis of osteoarthritis (OA). We examined the effects of T helper (Th) cells, which induce the expression of macrophage inflammatory protein (MIP-1γ), on the progression of OA. DESIGN: Using anterior cruciate ligament-transection (ACLT), we induced OA in one hind-leg knee joint of B6 mice. The CD4(+) T cells from splenocytes and synovium were flow-cytometrically and immunochemically evaluated, respectively. The knee joints were histologically assessed for manifestations of OA. MIP-1γ levels and nuclear factor-κB (NF-κB) in the knee joints were measured using enzyme-linked immunosorbent and immunoblotting assays, respectively; osteoclastogenesis was detected by tartrate-resistant acid phosphatase (TRAP) staining. The inflammatory responses and MIP-1γ expression were examined using immunohistochemistry. RESULTS: The number of CD4(+) T cells and the expression of interferon-γ (IFN-γ) increased during OA onset (30 days after ACLT) and then decreased at a later stage of OA (90 days after ACLT). Tissue damage induced by CD4(+) T cells was evident at the later stage. The activation of CD4(+) T cells induced the expression of MIP-1γ and NF-κB. The expression of MIP-1γ can be detected in synovium which CD4(+) T cells were infiltrated. The increased MIP-1γ expression caused an increase in the number of osteoclasts in joints. The regulation of CD4(+) T cells was accompanied by increased macrophage infiltration and matrix metalloproteinase (MMP)-9 expression. Histopathological examinations revealed that CD4(+) T cell knockout (CD4(-/-)) mice had less expression of MIP-1γ and slower cartilage degeneration than control mice had. CONCLUSIONS: CD4(+) T cells were activated during the onset of OA, but cartilage damage was more prominent at a later stage. CD4(+) T cells were involved in the pathogenesis of OA: they induced MIP-1γ expression and subsequent osteoclast formation.


Subject(s)
Macrophage Inflammatory Proteins/metabolism , Osteoarthritis, Knee/immunology , Osteoarthritis, Knee/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Animals , Disease Progression , Flow Cytometry , Immunohistochemistry , Mice , NF-kappa B/metabolism
9.
J Hand Surg Eur Vol ; 36(3): 236-43, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21282223

ABSTRACT

Despite known detrimental effects on the blood flow and histology of nerves after intraneural corticosteroid injection, the neurotoxic effect of corticosteroids remains unclear. We investigated the effect of topical dexamethasone on nerve function. Two sponge strips soaked with dexamethasone at doses of 0.8, 1.6, and 3.2 mg were placed under and over the left sciatic nerve of adult Wistar rats for 30 minutes. Mixed-nerve-elicited somatosensory evoked potentials and dermatomal somatosensory evoked potentials were evaluated immediately and repeated together with functional tests and histology 2 weeks later. Evoked potential amplitude was dose-dependently lower and latency was prolonged in dexamethasone-treated sciatic nerves compared to controls. The suppression persisted with incomplete recovery for at least 4 hours, but differences between treated and control nerves were not significant after 2 weeks. Topical dexamethasone adversely affected neural conduction in a dose-dependent manner. Our results suggest that caution is required when using large doses of corticosteroid for injection of the carpal tunnel.


Subject(s)
Carpal Tunnel Syndrome/drug therapy , Dexamethasone/administration & dosage , Evoked Potentials, Somatosensory/drug effects , Glucocorticoids/administration & dosage , Neural Conduction/drug effects , Sciatic Nerve/drug effects , Administration, Topical , Animals , Dexamethasone/adverse effects , Dose-Response Relationship, Drug , Glucocorticoids/adverse effects , Rats , Rats, Wistar , Reaction Time/drug effects , Sciatic Nerve/pathology , Sciatic Nerve/physiopathology
10.
Article in English | MEDLINE | ID: mdl-22256199

ABSTRACT

Trigger finger is a common hand disease, causing swelling, painful popping and clicking in moving the affected finger joint. To better evaluate patients with trigger finger, segmentation of flexor tendons from magnetic resonance (MR) images of finger joints, which can offer detailed structural information of tendons to clinicians, is essential. This paper presents a novel model-based method with three stages for automatically segmenting the flexor tendons. In the first stage, a set of tendon contour models (TCMs) is initialized from the most proximal cross-sectional image via two-step ellipse estimation. Each of the TCMs is then propagated to its distally adjacent image by affine registration. The propagation is sequentially performed along the proximal-distal direction until the most distal image is reached, as the second stage of segmentation. The TCMs on each cross-sectional image are refined in the last stage with the snake deformation. MR volumes of three subjects were used to validate the segmentation accuracy. Compared with the manual results, our method showed good accuracy with small average margins of errors (within 0.5 mm) and large overlapping ratio (dice similarity coefficient above 0.8). Overall, the proposed method has great potential for morphological change assessment of flexor tendons and pulley-tendon system modeling for image guided surgery.


Subject(s)
Finger Joint/anatomy & histology , Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Models, Anatomic , Tendons/anatomy & histology , Humans
11.
J Hand Surg Eur Vol ; 34(1): 66-71, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19129353

ABSTRACT

We examined 40 wrists of 12 embalmed and eight fresh cadavers and defined the relative position of the flexor retinaculum to the neurovascular structure, ultrasonographic markers and safe zones by ultrasonography and anatomical dissection. Both longitudinal and transverse ultrasonographic sections clearly depicted the flexor retinaculum, neurovascular bundles, median nerve, flexor tendons and bony boundaries of the underlying joints. Topographic measurement showed [i] good correlation between the actual extent of the flexor retinaculum and the ultrasonographically determined distance between bony landmarks in all hands, and [ii] the widths and lengths of well-defined safe zones. A comparison study confirmed the accuracy of ultrasonography. We conclude that these ultrasonographic landmarks can locate the flexor retinaculum and facilitate safe and complete carpal tunnel release with open or minimally invasive techniques.


Subject(s)
Carpal Tunnel Syndrome/diagnostic imaging , Carpal Tunnel Syndrome/pathology , Decompression, Surgical , Endoscopy , Adolescent , Adult , Aged , Carpal Bones/diagnostic imaging , Carpal Bones/pathology , Carpal Tunnel Syndrome/surgery , Female , Humans , Male , Microsurgery , Middle Aged , Reference Values , Sensitivity and Specificity , Tendons/diagnostic imaging , Tendons/pathology , Tendons/surgery , Ultrasonography , Young Adult
12.
J Bone Joint Surg Br ; 90(5): 657-61, 2008 May.
Article in English | MEDLINE | ID: mdl-18450636

ABSTRACT

We evaluated the morphological changes to the ulnar nerve of both elbows in the cubital tunnel by sonography in a total of 237 children, of whom 117 were aged between six and seven years, 66 between eight and nine years, and 54 between ten and 11 years. We first scanned longitudinally in the extended elbow and then transversely at the medial epicondyle with the elbow extended to 0 degrees . We repeated the scans with the elbow flexed at 45 degrees , 90 degrees , and 120 degrees . There were no significant differences in the area of the ulnar nerve, but the diameter increased as the elbow moved from extension to flexion in all groups. More importantly, the ulnar nerve was subluxated anteriorly on to the medial epicondyle by 1.5% to 1.9% in extended elbows, by 5.9% to 7.9% in those flexed to 45 degrees , by 40.0% to 44% in those flexed to 90 degrees , and by 57.4% to 58.1% in those flexed to 120 degrees , depending on the age group. Sonography clearly and accurately showed the ulnar nerve and was useful for localising the nerve before placing a medial pin. Because the ulnar nerve may translate anteriorly onto the medial epicondyle when the elbow is flexed to 90 degrees or more, it should never be overlooked during percutaneous medial pinning.


Subject(s)
Elbow Joint/diagnostic imaging , Range of Motion, Articular/physiology , Ulnar Nerve/diagnostic imaging , Analysis of Variance , Child , Elbow Joint/physiology , Female , Humans , Male , Ulnar Nerve/physiology , Ultrasonography
13.
J Hand Surg Br ; 31(2): 191-9, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16376004

ABSTRACT

This study introduces a sonographically assisted percutaneous technique for releasing trigger digits which provides direct visualization of the release and avoids the risks of incomplete release and injury to adjacent neurovascular structures associated with other percutaneous release techniques. The "safe zone" and an estimate of the size of the A1 pulley were determined in a separate cadaver study. We then used these landmarks in a prospective clinical study of 107 digits in 83 consecutive patients treated by this technique. During the follow-ups of between 9 and 15 months, we evaluated 104 digits in 80 patients. Pain was absent in 101 digits (97%) and considerably improved in the other three (3%). All mechanical problems had been resolved and none recurred during follow-up. This technique allows the surgeon to see and monitor, precisely, the percutaneous division of the A1 pulley without open surgery and, therefore, to avoid the inherent risks of percutaneous and open surgical release.


Subject(s)
Finger Joint/surgery , Fingers/surgery , Orthopedic Procedures/methods , Tenosynovitis/surgery , Thumb/surgery , Adolescent , Adult , Aged , Aged, 80 and over , Female , Finger Joint/diagnostic imaging , Fingers/diagnostic imaging , Humans , Male , Middle Aged , Tenosynovitis/diagnostic imaging , Thumb/diagnostic imaging , Ultrasonography
14.
Anesth Analg ; 92(6): 1547-51, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11375844

ABSTRACT

We sought to determine the possible neural conduction blockade of tramadol and whether there is evidence of localized neural toxicity with spinal somatosensory evoked potential (SSEP) measurements. Male Wistar rats were used. SSEP, elicited by supramaximally stimulating the hind paw and recorded from the thoracolumbar and the first and second lumbar interspinous ligaments, was monitored. SSEPs were obtained before drug application as the pretreatment baseline and measured every 15 min after treatment for 2 h and at 60-min intervals thereafter until SSEP returned to baseline or for another 4 h. Two small strips of Gelfoam (0.6 x 1.0 cm(2)) soaked with the drug were placed under and over the left sciatic nerve for a 30-min period. Gelfoam was prepared with tramadol hydrochloride (Tramal; the US trade name is Ultram) 5, 2.5, and 1.25 mg, diluted if needed with saline to a total volume of 100 microL (5%, 2.5%, and 1.25%, respectively). The control data were obtained from the right side limb with normal saline by following the same method. Spinal SSEPs were measured after 48 h to detect the late neural damage. The results showed that direct tramadol application on sciatic nerves dose-dependently reduced both the amplitude and conduction velocity of SSEPs when compared with the pretreatment baseline. All SSEPs returned to pretreatment baseline, and no significant changes of SSEP between bilateral limbs were noted at the 48-h measurements. No evidence of irreversible conduction blockade indicative of local neural toxicity was seen. Pretreatment with naloxone 1 mg/kg failed to block the changes of SSEP produced by 2.5% tramadol 100 microL. We conclude that tramadol exerts a local anesthetic-type effect on peripheral nerves.


Subject(s)
Analgesics, Opioid/pharmacology , Evoked Potentials, Somatosensory/drug effects , Sciatic Nerve/drug effects , Tramadol/pharmacology , Analgesics, Opioid/administration & dosage , Animals , Dose-Response Relationship, Drug , Male , Rats , Rats, Wistar , Tramadol/administration & dosage
15.
J Orthop Res ; 19(6): 1147-52, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11781017

ABSTRACT

Patients with Crowe Type-IV congenital dislocation of the hip (CDH) show significant clinical improvement after total hip arthroplasty (THA) because this surgery greatly reduces pain. Concomitant leg-length equalization in unilateral patients--a controversial procedure--theoretically should significantly improve these patients' ability to walk efficiently and comfortably. To understand the impact of leg-length equalization on these patients, we compared their gait parameters with those of untreated patients without pain but with leg-length discrepancy. Using a motion analysis system, three force platforms and computer calculation, the gait parameters during level walking of 22 women with unilateral Crowe Type-IV CDH were studied at an average of 58 months (27-98 months) following a successful cementless THA. The socket was placed in the best bone stock, which was close to the level of the true acetabulum. The leg-length discrepancy was equalized to within 2 cm in all patients. The Harris hip score averaged 94.8 (range, 88-100) at the time of the study. Nine women with untreated unilateral Crowe Type-IV CDH without major pain but with an average leg-length discrepancy of 4.7 cm (range, 2.5-6 cm) were also studied for comparison. The treated subjects (Group 1; THA and leg-length equalization) walked faster and had gait parameters with better bilateral symmetry than the untreated subjects (Group 2). We concluded that leg-length equalization in addition to THA in patients with unilateral Crowe Type-IV CDH significantly improves gait symmetry and efficiency.


Subject(s)
Arthroplasty, Replacement, Hip , Gait , Hip Dislocation, Congenital/surgery , Leg Length Inequality/surgery , Adult , Female , Hip Dislocation, Congenital/physiopathology , Humans
16.
J Appl Physiol (1985) ; 89(5): 1766-70, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11053324

ABSTRACT

Our new oropharyngeal intubation wedge made from a plastic 3-ml syringe has been used successfully for the expansion of the oropharyngeal cavity and visualization of vocal cords for endotracheal intubation in the rat. All the animals we used tolerated the intubation and ventilation procedures in a series of experiments. After the proper setting of the respirator, vital signs were maintained within normal range. The postmortem examination and measurements in the upper airway confirmed that the endotracheal tube was properly sited and also demonstrated the precise size of the device that should be used. The main advantages of this method include low cost, simplicity, and reliability. Furthermore, because no expensive, elaborate, difficult-to-operate, or hard-to-get special equipment is needed, this technique can be used in every laboratory.


Subject(s)
Intubation, Intratracheal/instrumentation , Intubation, Intratracheal/methods , Rats, Sprague-Dawley , Syringes , Animals , Pharynx , Rats , Rats, Wistar , Respiration, Artificial , Trachea , Vocal Cords
17.
Clin Rheumatol ; 19(5): 385-8, 2000.
Article in English | MEDLINE | ID: mdl-11055829

ABSTRACT

The authors report a rare concomitant pyogenic infection of the iliopsoas, iliacus and external obturator muscles and of the hip joint in a 68-year-old woman. Because the patient showed the classic symptomatic triad of limping, hip pain and fever, in addition to positive hip arthrocentesis, the diagnosis of septic hip arthritis was routine, but the simultaneous pyomyositis was almost overlooked. Unusual localised heat and swelling on the front of the proximal thigh prompted a CT scan that identified remarkable muscle abscesses in addition to the septic arthritis. Surgical debridement and antibiotics resolved the infection relatively rapidly without sequelae. We noted that reaching a definitive diagnosis of such a concomitant infection requires a suspicion of the presence of pyomyositis, which can be definitively determined using advanced imaging studies.


Subject(s)
Arthritis, Infectious/complications , Hip Joint , Myositis/complications , Staphylococcal Infections/complications , Aged , Anti-Bacterial Agents , Arthritis, Infectious/diagnosis , Arthritis, Infectious/drug therapy , Arthritis, Infectious/microbiology , Diagnosis, Differential , Drug Therapy, Combination/therapeutic use , Female , Hip Joint/diagnostic imaging , Hip Joint/microbiology , Hip Joint/pathology , Humans , Magnetic Resonance Imaging , Muscle, Skeletal/diagnostic imaging , Muscle, Skeletal/microbiology , Muscle, Skeletal/pathology , Myositis/diagnosis , Myositis/drug therapy , Myositis/microbiology , Staphylococcal Infections/diagnosis , Staphylococcal Infections/drug therapy , Staphylococcal Infections/microbiology , Staphylococcus aureus/isolation & purification , Suppuration , Tomography, X-Ray Computed
18.
Spine (Phila Pa 1976) ; 25(15): 1878-85, 2000 Aug 01.
Article in English | MEDLINE | ID: mdl-10908929

ABSTRACT

STUDY DESIGN: Acute spinal cord injury was induced by a clip compression model in rats to approximate spinal cord injury encountered in spinal surgery. Spinal somatosensory-evoked potential neuromonitoring was used to study the electrophysiologic change. OBJECTIVES: To compare and correlate changes in evoked potential after acute compression at different core temperatures with postoperative neurologic function and histologic change, to evaluate current intraoperative neuromonitoring warning criteria for neural damage, and to confirm the protective effect of hypothermia in acute spinal cord compression injury by electrophysiologic, histologic, and clinical observation. SUMMARY OF BACKGROUND DATA: With the increase in aggressive correction of spinal deformities, and the invasiveness of surgical instruments, the incidence of neurologic complication appears to have increased despite the availability of sensitive intraoperative neuromonitoring techniques designed to alert surgeons to impending neural damage. Many reasons have been given for the frequent failures of neuromonitoring, but the influence of temperature-a very important and frequently encountered factor-on evoked potential has not been well documented. Specifically, decrease in amplitude and elongation of latency seem not to have been sufficiently taken into account when intraoperative neuromonitoring levels were interpreted and when acceptable intraoperative warning criteria were determined. METHODS: Experimental acute spinal cord injury was induced in rats by clip compression for two different intervals and at three different core temperatures. Spinal somatosensory-evoked potential, elicited by stimulating the median nerve and recorded from the cervical interspinous C2-C3, was monitored immediately before and after compression, and at 15-minute intervals for 1 hour. RESULTS: Spinal somatosensory-evoked potential change is almost parallel to temperature-based amplitude reduction and latency elongation. Significant neurologic damage induced by acute compression of the cervical spinal cord produced a degree of effect on the amplitude of spinal somatosensory-evoked potential in normothermic conditions that differed from the effect in moderately hypothermic conditions. Using the same electromonitoring criteria,moderately hypothermic groups showed a significantly higher false-negative rate statistically (35%) than normothermic groups (10%). CONCLUSIONS: Systemic cooling may protect against the detrimental effects of aggressive spinal surgical procedures. There is still not enough published information available to establish statistically and ethically acceptable intraoperative neuromonitoring warning and intervention criteria conclusively. Therefore, an urgent need exists for further investigation. Although a reduction of more than 50% in evoked potential still seems acceptable as an indicator of impending neural function loss, maintenance of more than 50% of baseline evoked potential is no guarantee of normal postoperative neural function, especially at lower than normal temperatures.


Subject(s)
Body Temperature/physiology , Evoked Potentials, Somatosensory/physiology , Spinal Cord Compression/physiopathology , Acute Disease , Animals , Disease Models, Animal , Hemorrhage/pathology , Hypothermia, Induced , Monitoring, Intraoperative , Motor Activity/physiology , Rats , Rats, Sprague-Dawley , Reaction Time/physiology , Sensation/physiology , Spinal Cord/pathology , Spinal Cord Compression/pathology
19.
Clin Radiol ; 55(5): 353-5, 2000 May.
Article in English | MEDLINE | ID: mdl-10816400

ABSTRACT

AIM: The accuracy of bone scintigraphy in diagnosing symptomatic accessory navicular bones has not been well studied. We conducted a retrospective study to explore the results and use of scintigraphy in symptomatic and asymptomatic accessory navicular bones. MATERIALS AND METHODS: Thirteen patients with a total of 13 symptomatic and 10 asymptomatic accessory navicular bones were included in the study. We used a scoring system to grade the scintigraphic abnormalities. The patients' symptoms and scintigraphic findings were recorded. RESULTS: Though focally increased radiopharmaceutical uptake was observed in all symptomatic accessory naviculars, half of the asymptomatic accessory navicular bones had the same manifestations. The scoring system was of no value in differentiating symptomatic from asymptomatic accessory navicular bones. CONCLUSION: Bone scintigraphy is a sensitive but not a specific tool for diagnosing a symptomatic accessory navicular.


Subject(s)
Foot Deformities, Congenital/diagnostic imaging , Radiopharmaceuticals , Tarsal Bones/abnormalities , Technetium Tc 99m Medronate , Adolescent , Adult , Child , Female , Humans , Male , Radionuclide Imaging , Retrospective Studies , Sensitivity and Specificity , Tarsal Bones/diagnostic imaging
20.
J Orthop Res ; 18(1): 149-55, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10716291

ABSTRACT

The effects of an acute stretch on evoked potential, blood flow, histological change, and clinical neurological state were studied in a rat model of acute nerve stretch induced by femoral lengthening. The purposes of this study were to assess, in a model of acute limb lengthening, the safe limits of nerve stretch for nerve function, the pathogenesis of nerve dysfunction, the sensitivity of spinal somatosensory evoked potential, and one of the proposed criteria for irreversible compromise of the sciatic nerve. Thirty-two rats were assigned to one of four groups defined by the degree of acute femoral lengthening (8, 16, 24, and 32%). Spinal somatosensory evoked potential at L5/6 following stimulation of the sciatic nerve was recorded before, immediately after, and 30 minutes after lengthening. Sciatic nerve blood flow was measured by laser Doppler flowmetry at the stretched site before and after lengthening. One week after the operation and without further lengthening, clinical neurological status was evaluated by the functional index of the sciatic nerve and histological examination was performed. At the measurement immediately after the procedure, amplitude changed significantly in all groups except for the group with 8% lengthening. In all groups, sciatic nerve blood flow also dropped significantly compared with values for the control side. Moreover, a greater percentage increase in acute lengthening corresponded with more marked changes in spinal somatosensory evoked potential and sciatic nerve blood flow. The groups that underwent acute lengthening of 24 and 32% had significant neurological deficits and histological changes and demonstrated a significant and profound (50%) drop in amplitude and blood flow. We concluded that spinal somatosensory evoked potential is very sensitive and may serve as an effective tool for the early detection of impending acute nerve-stretch injury and that a 50% reduction in amplitude indicates irreversible damage.


Subject(s)
Bone Lengthening , Neural Conduction , Sciatic Nerve/injuries , Acute Disease , Animals , Evoked Potentials, Somatosensory , Femur/surgery , Laser-Doppler Flowmetry , Rats , Rats, Sprague-Dawley , Regional Blood Flow , Sciatic Nerve/blood supply , Sciatic Nerve/physiology
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