The differential effects of norepinephrine and dopamine on cerebrospinal fluid pressure and spinal cord perfusion pressure after acute human spinal cord injury.

STUDY DESIGN: Prospective vasopressor cross-over interventional studyObjectives:To examine how two vasopressors used in acute traumatic spinal cord injury (SCI) affect intrathecal cerebrospinal fluid pressure and the corresponding spinal cord perfusion pressure (SCPP). SETTING: Vancouver, British Columbia, Canada. METHODS: Acute SCI patients over the age of 17 with cervical or thoracic ASIA Impairment Scale (AIS). A, B or C injuries were enrolled in this study. Two vasopressors, norepinephrine and dopamine, were evaluated in a 'crossover procedure' to directly compare their effect on the intrathecal pressure (ITP). The vasopressor cross-over procedures were performed in the intensive care unit where ITP, mean arterial pressure (MAP) and heart rate were being continuously measured. The SCPP was calculated as the difference between MAP and ITP. RESULTS: A total of 11 patients were enrolled and included in our analysis. There were 6 patients with AIS A, 3 with AIS B and 2 with AIS C injuries at baseline. We performed 24 cross-over interventions in these 11 patients. There was no difference in MAP with the use of norepinephrine versus dopamine (84±1 mm Hg for both; P=0.33). Conversely, ITP was significantly lower with the use of norepinephrine than with dopamine (17±1 mm Hg vs 20±1 mm Hg, respectively, P<0.001). This decrease in ITP with norepinephrine resulted in an increased SCPP during the norepinephrine infusion when compared with dopamine (67±1 mm Hg vs 65±1 mm Hg respectively, P=0.0049). CONCLUSION: Norepinephrine was able to maintain MAP with a lower ITP and a correspondingly higher SCPP as compared with dopamine in this study. These results suggest that norepinephrine may be preferable to dopamine if vasopressor support is required post SCI to maintain elevated MAPs in accordance with published guidelines.

Clinically orientated classification incorporating shoulder balance for the surgical treatment of adolescent idiopathic scoliosis.

PURPOSE: The achievement of shoulder balance is an important measure of successful scoliosis surgery. No previously described classification system has taken shoulder balance into account. We propose a simple classification system for AIS based on two components which include the curve type and shoulder level. METHODS: Altogether, three curve types have been defined according to the size and location of the curves, each curve pattern is subdivided into type A or B depending on the shoulder level. This classification was tested for interobserver reproducibility and intraobserver reliability. A retrospective analysis of the radiographs of 232 consecutive cases of AIS patients treated surgically between 2005 and 2009 was also performed. RESULTS: Three major types and six subtypes were identified. Type I accounted for 30 %, type II 28 % and type III 42 %. The retrospective analysis showed three patients developed a decompensation that required extension of the fusion. One case developed worsening of shoulder balance requiring further surgery. This classification was tested for interobserver and intraobserver reliability. The mean kappa coefficients for interobserver reproducibility ranged from 0.89 to 0.952, while the mean kappa value for intraobserver reliability was 0.964 indicating a good-to-excellent reliability. CONCLUSIONS: The treatment algorithm guides the spinal surgeon to achieve optimal curve correction and postoperative shoulder balance whilst fusing the smallest number of spinal segments. The high interobserver reproducibility and intraobserver reliability makes it an invaluable tool to describe scoliosis curves in everyday clinical practice.

Back pain in children and adolescents.

Back pain is a common symptom in children and adolescents. Here we review the important causes, of which defects and stress reactions of the pars interarticularis are the most common identifiable problems. More serious pathology, including malignancy and infection, needs to be excluded when there is associated systemic illness. Clinical evaluation and management may be difficult and always requires a thorough history and physical examination. Diagnostic imaging is obtained when symptoms are persistent or severe. Imaging is used to reassure the patient, relatives and carers, and to guide management.

Early results of a remotely-operated magnetic growth rod in early-onset scoliosis.

Conventional growing rods are the most commonly used distraction-based devices in the treatment of progressive early-onset scoliosis. This technique requires repeated lengthenings with the patient anaesthetised in the operating theatre. We describe the outcomes and complications of using a non-invasive magnetically controlled growing rod (MCGR) in children with early-onset scoliosis. Lengthening is performed on an outpatient basis using an external remote control with the patient awake.Between November 2009 and March 2011, 34 children with a mean age of eight years (5 to 12) underwent treatment. The mean length of follow-up was 15 months (12 to 18). In total, 22 children were treated with dual rod constructs and 12 with a single rod. The mean number of distractions per patient was 4.8 (3 to 6). The mean pre-operative Cobb angle was 69° (46° to 108°); this was corrected to a mean 47° (28° to 91°) post-operatively. The mean Cobb angle at final review was 41° (27° to 86°). The mean pre-operative distance from T1 to S1 was 304 mm (243 to 380) and increased to 335 mm (253 to 400) in the immediate post-operative period. At final review the mean distance from T1 to S1 had increased to 348 mm (260 to 420).Two patients developed a superficial wound infection and a further two patients in the single rod group developed a loss of distraction. In the dual rod group, one patient had pull-out of a hook and one developed prominent metalwork. Two patients had a rod breakage; one patient in the single rod group and one patient in the dual rod group. Our early results show that the MCGR is safe and effective in the treatment of progressive early-onset scoliosis with the avoidance of repeated surgical lengthenings.

Severe brachial plexus injuries in rugby.

We describe the mechanisms, pattern of injuries, management and outcomes of severe injuries to the brachial plexus sustained during the play of rugby. Thirteen cases of severe injury to the brachial plexus caused by tackles in rugby had detailed clinical assessment, and operative exploration of the brachial plexus. Seventeen spinal nerves were avulsed, two were ruptured and there were traction lesions in continuity of 24 spinal nerves. The pattern of nerve lesion was related to the posture of the neck and the forequarter at the moment of impact. Early repair by nerve transfer enabled some functional recovery, and decompression of lesions in continuity was followed by recovery of nerve function and relief of pain.

Repair of spondylolysis using compression with a modular link and screws.

We describe the results of a prospective case series of patients with spondylolysis, evaluating a technique of direct stabilisation of the pars interarticularis with a construct that consists of a pair of pedicle screws connected by a U-shaped modular link passing beneath the spinous process. Tightening the link to the screws compresses bone graft in the defect in the pars, providing rigid intrasegmental fixation. We have carried out this procedure on 20 patients aged between nine and 21 years with a defect of the pars at L5, confirmed on CT. The mean age of the patients was 13.9 years (9 to 21). They had a grade I or less spondylolisthesis and no evidence of intervertebral degeneration on MRI. The mean follow-up was four years (2.3 to 7.3). The patients were assessed by the Oswestry Disability Index (ODI) and a visual analogue scale (VAS). At the latest follow-up, 18 patients had an excellent clinical outcome, with a significant (p < 0.001) improvement in their ODI and VAS scores. The mean ODI score at final follow-up was 8%. Assessment of the defect by CT showed a rate of union of 80%. There were no complications involving the internal fixation. The strength of the construct removes the need for post-operative immobilisation.

The anatomical basis of the medial sural artery perforator flaps.

OBJECTIVES: To study the perforators of the medial sural artery and the possible size of their flap. METHODS: The external iliac arteries often adult preserved cadavers (males and females) were injected with a mixture of red latex and lead oxide. The skin was reflected and the medial sural artery and its perforators were identified. The diameters and origins of perforators were measured from the central popliteal crease. RESULTS: The medial sural artery originated from the popliteal artery in 70% and had its external diameter at a mean of 3 +/- 0.02 mm and was accompanied by two venae comitantes. The number of its perforators was at a mean of two perforators. Length of the pedicle of the medial sural artery perforator flap was at a mean of 18 +/- 0.03 cm. The largest of the perforator had an average external diameter of 0.9 mm. The perforators ramified the skin with branches of the artery accompanying the posterior cutaneous nerve and the perforating branches of the peroneal and the posterior tibial arteries. The possible size of the medial sural perforators flap was at an average 8.2 cm x 13.3 cm. CONCLUSION: The medial sural artery perforator flap has at least one or two perforators with an average size of 8.2 cm x 13.3 cm. Elevation of the flap will not affect the vascularity of the gastrocnemius muscle.

Cerebral venous sinus thrombosis following cervical disc arthroplasty.

Cerebral venous sinus thrombosis is a rare condition, which is difficult to diagnose. It has not previously been reported following surgery to the cervical spine . We report such a case in a 45-year-old man after cervical disc replacement. A high index of suspicion, with early imaging of the brain and prompt treatment, can produce a favourable outcome, albeit not in this case.

A case of necrotising fasciitis caused by Pseudomonas aeruginosa.

Necrotising fasciitis is a rare but severe infection of soft-tissue associated with rapid progression, systemic toxicity and high mortality. Monomicrobial necrotising fasciitis caused by Pseudomonas aeruginosa is exceptionally uncommon with only 12 cases reported in the literature. We describe a fatal case with an atypical presentation in a patient following spinal decompression for a metastasis from prostate cancer.

Cyclical sciatica: endometriosis of the sciatic nerve.

We describe a case of sciatic endometriosis in a 25-year-old woman diagnosed by MRI and histology with no evidence of intrapelvic disease. The presentation, diagnosis and management of this rare condition are described. Early diagnosis and treatment are important to prevent irreversible damage to the sciatic nerve.

Ascorbate-enhanced chondrogenesis of ATDC5 cells.

The ATDC5 cell line exhibits the multistep chondrogenic differentiation observed during endochondral bone formation. However, it takes up to two months to complete the process of cell expansion, insulin addition to promote differentiation and further changes in culture conditions effectively to induce hypertrophy. We sought to produce consistent chondrogenesis with significant hypertrophic differentiation with simpler conditions in a more practical time period. By adding ascorbate, the prechondrogenic proliferation phase was shortened from 21 to 7 days, with production of cartilaginous nodules during the chondrogenic phase, after insulin addition, that were greater in number and larger in size. Immunohistochemistry indicated much greater matrix elaboration and the mRNA expression of sox9, aggrecan and collagen type II were all significantly increased earlier and to a much higher degree when compared with controls. Moreover, there was a robust induction of hypertrophy: Col10a1, Runx2 and Mmp13 were all induced within 7-10 days. In conclusion, addition of ascorbate to ATDC5 cultures shortened the prechondrogenic proliferation phase, produced earlier chondrogenic differentiation, heightened gene expression and robust hypertrophic differentiation, abrogating the need for extended culture times and the changes in culture conditions. This simple modification considerably enhances the practicality of this cell line for studies of chondrogenesis.

Histopathology of adenoid cystic carcinoma of the larynx and adenocarcinoma hybrid.

A 35-year-old Saudi female presented to the Ear, Nose and Throat clinic complaining of hoarseness of voice. Examination revealed subglottic mass, which proved to be adenoid cystic carcinoma of the larynx with adenocarcinoma hybrid. In this paper we discuss the pathological features and electron microscopy of adenoid cystic carcinoma in detail, including its differential diagnosis, prognosis and treatment.

Hepatocellular carcinoma.

OBJECTIVE: To establish the most common pathological criteria to diagnose hepatocellular carcinoma, and to identify the high-risk patients for further investigation in order to detect hepatocellular carcinoma in its early stages. METHODS: A retrospective study was carried out at King Khalid National Guard Hospital including 60 cases diagnosed as hepatocellular carcinoma cytologically and histopathologically. Further investigations were performed by special staining and immunohistochemical staining on 42 blocks including Periodic acid-schiff, PAS-D, Reticulin, Iron and Alpha Fetoprotein, hepatitis B surface antigen, hepatitis B core antigen and p53 antibodies. RESULTS: It was found that pleomorphism, followed by presence of prominent nucleoli and nuclear pseudoinclusion were the most frequent finding in hepatocellular carcinoma. While considering other studies, reticulin framework, glycogen and iron content of the hepatocellular carcinoma were markedly diminished as compared to non-malignant liver tissue. Antibodies against tumor suppressor gene was applied on paraffin section (p53), it was positive in 52% of cases and 53% of them were having anti hepatitis B surface antigen positivity, detected in their serum and 23% were having hepatitis C antibodies positive. CONCLUSION: Hepatocellular carcinoma is a common malignancy that can be detected by certain defined pathological parameters and should be suspected in high-risk patient.