Hypothesis Athletes significantly alter their lumbar spinal motion when performing squat lifting at heavy weights. This altered motion effects a change in pressure in the posterior annulus of lumbar discs. Methods 48 athletes performed 6 lifts at 40% maximum, 4 lifts at 60% maximum and 2 lifts at 80% maximum. Zebris 3-D motion analysis system used to measure lumbar spine motion. Exercise then repeated with weight lifting support belt. 4 cadaveric sheep spinal motion segments fixed to tension/compression loading frame, allowing compression replicating the forces seen in in vivo study. Pressure measurement achieved using a Flexiforce single element force sensor strip, positioned at posterior annulus. Posterior annulus pressure measured during axial compression and on compression with specimen fixed at 3° of extension. Results Significant decrease (p Comparing axially loaded specimens with specimens loaded in extension, there was an average increase in pressure of 36.4% in the posterior annulus, when the spine was loaded in 3° of extension at a pressure equivalent to the 80% lift in the in vivo motion study, in comparison to axial loading. Conclusions Squat weight lifting at heavier weights, causes athletes to lift at a progressively greater degree of extension. The use of a weight lifting support belt does not significantly alter spinal motion during lifting. The increased extension at heavier weights results in a stress concentration in the posterior annulus.

The angle bore socket was designed by surgeons at the Charnley Institute in Wrightington and introduced clinically in 1983. The socket was designed to provide increased coverage to the prosthetic femoral head during Xexion, adduction and internal rotation, in an effort to decrease the rate of dislocation. It achieves this by using a chamfer, which is angled at 45 to the bore of the socket and is discontinuous anteriorly, preventing impingement between the socket and prosthetic femoral neck during Xexion, adduction and internal rotation. We report the 15-year experience of the senior author with the angle bore socket in patients with an increased dislocation risk, secondary to increased age with general poor mobility and muscle function, decreased cognitive ability, recurrent dislocation and decreased muscle function secondary to co-morbid illness. Between 1990 and 2005, 54 patients underwent a total hip replacement using an angle bore socket. Of these patients, only one suffered a recurrent episode of dislocation post-operatively, requiring further surgery. The dislocation rate of 1.85% seen in this study suggests that this prosthesis can decrease the incidence of dislocation in vulnerable patients. In these patients, with a low activity level and/ or short life expectancy, the benefit of the increased stability provided by the angle bore socket outweighs the limitations imposed by increased constraint.

The angle bore socket was designed by surgeons at the Charnley Institute in Wrightington and introduced clinically in 1983. The socket was designed to provide increased coverage to the prosthetic femoral head during flexion, adduction and internal rotation, in an effort to decrease the rate of dislocation. It achieves this by using a chamfer, which is angled at 45° to the bore of the socket and is discontinuous anteriorly, preventing impingement between the socket and prosthetic femoral neck during flexion, adduction and internal rotation. We report the 15-year experience of the senior author with the angle bore socket in patients with an increased dislocation risk, secondary to increased age with general poor mobility and muscle function, decreased cognitive ability, recurrent dislocation and decreased muscle function secondary to co-morbid illness. Between 1990 and 2005, 54 patients underwent a total hip replacement using an angle bore socket. Of these patients, only one suffered a recurrent episode of dislocation post-operatively, requiring further surgery. The dislocation rate of 1.85% seen in this study suggests that this prosthesis can decrease the incidence of dislocation in vulnerable patients. In these patients, with a low activity level and/or short life expectancy, the benefit of the increased stability provided by the angle bore socket outweighs the limitations imposed by increased constraint.

The L4/5 disc inter-space is commonly believed to be represented by a line drawn between the two highest points of the iliac crests. This line is frequently used as a pre-operative guide for incision placement, in patients undergoing spinal surgery. We reviewed the antero-posterior and lateral lumbar spine films of 450 patients, ranging in age from 20 to 90 years, measuring the distance from the supracristal plane to the midpoint of the L4/5 disc interspace. The plane intersected the spine at the L4/5 interspace in only 31.9% of cases and was found to lie at the lower half of the body of L4 or above in 49.5% of cases. There was significant variation in the position of the supracristal plane between the different patient age groups studied (P≤0.05). The use of additional imaging, along with plain radiography is advised when attempting identification of this spinal level, as reliance on palpation of the iliac crests alone to identify this landmark may lead to unintentional cranial placement of a surgical incision during spinal procedures, or cannulation at a level above the intended interspace, during epidural and spinal anaesthesia.

We report a case of Nora's lesion (bizarre parosteal osteochondromatous proliferation) of the fifth metatarsal. A 56 year old male, presented with a painless, gradually enlarging swelling over the lateral aspect of his left foot, of 2 years in duration. Plain radiography and MRI showed features consistent with a bizarre parosteal osteochondromatous proliferation of bone (Nora's lesion). The mass was excised and the lesion confirmed histologically. This benign lesion can be confused with malignancy. However, it exhibits a number of key radiographic and histological features, which differentiate it from other benign and malignant processes. It has a strong propensity for recurrence. However this can be decreased by excision of the pseudocapsule, underlying periosteum and removal of any abnormal cortical tissue beneath the lesion.

Proprietary femoral plug introducers are routinely used to insert intramedullary plugs during total hip arthroplasty The cement restrictor pin from an Exeter intramedullary plug introducer may become detached during insertion of the cement restrictor plug, or during sponge packing of the femur. We suggest some precautions that should be taken to prevent this from occurring and advise that the patient is unlikely to experience any long-term adverse reactions to the presence of the restrictor pin in the intramedullary canal.

Australian and New Zealand Journal of MedicineVolume 25, Issue 4 p. 374-375 Mitochondrial myopathy developing on treatment with the HMG CoA reductase inhibitors — simvastatin and pravastatin J. D. F. ENGLAND, Corresponding Author J. D. F. ENGLAND Visiting Medical Officer, Department of Cardiology, Westmead Hospital, Sydney, NSW3 Woodland road, Katoomba, NSW 2780Search for more papers by this authorJ. C. WALSH, J. C. WALSH Staff Specialist, Department of NeurologySearch for more papers by this authorP. STEWART, P. STEWART Staff Specialist, Department of Clinical Biochemistry, Royal Prince Alfred Hospital, Sydney, NSWSearch for more papers by this authorI. BOYD, I. BOYD Executive Officer, Therapeutic Drugs Administration, Department of Health, Housing and Community Services, Canberra, ACTSearch for more papers by this authorA. ROHAN, A. ROHAN Head, Therapeutic Drugs Administration, Department of Health, Housing and Community Services, Canberra, ACTSearch for more papers by this authorG. M. HALMAGYI, G. M. HALMAGYI Staff Specialist, Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW.Search for more papers by this author J. D. F. ENGLAND, Corresponding Author J. D. F. ENGLAND Visiting Medical Officer, Department of Cardiology, Westmead Hospital, Sydney, NSW3 Woodland road, Katoomba, NSW 2780Search for more papers by this authorJ. C. WALSH, J. C. WALSH Staff Specialist, Department of NeurologySearch for more papers by this authorP. STEWART, P. STEWART Staff Specialist, Department of Clinical Biochemistry, Royal Prince Alfred Hospital, Sydney, NSWSearch for more papers by this authorI. BOYD, I. BOYD Executive Officer, Therapeutic Drugs Administration, Department of Health, Housing and Community Services, Canberra, ACTSearch for more papers by this authorA. ROHAN, A. ROHAN Head, Therapeutic Drugs Administration, Department of Health, Housing and Community Services, Canberra, ACTSearch for more papers by this authorG. M. HALMAGYI, G. M. HALMAGYI Staff Specialist, Department of Neurology, Royal Prince Alfred Hospital, Sydney, NSW.Search for more papers by this author First published: August 1995 https://doi.org/10.1111/j.1445-5994.1995.tb01912.xCitations: 39AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume25, Issue4August 1995Pages 374-375 RelatedInformation

Eighty two patients with isolated optic neuritis were studied prospectively to determine the frequency with which multiple sclerosis developed and the factors which increased its risk. Patients were followed for 6 to 264 months (mean, 57 months). Twenty six patients (32%) developed clinically definite or probable multiple sclerosis during the period of follow-up. Actuarial analysis predicted that 42% would develop multiple sclerosis by 7 years. Of those patients who developed multiple sclerosis, 92% had symptoms within 4 years of the first attack of optic neuritis. The highest incidence of multiple sclerosis occurred in the 21-40 year age group. There was an increased risk of MS in patients with HLA-DR2 and HLA-B7 tissue types. The frequency of HLA-DR4 was increased in patients with optic neuritis alone compared to controls and to patients with multiple sclerosis, but further studies are required to confirm this finding.

Serial clinical and electrophysiological examinations and immunological investigations have been performed on 34 patients with primary optic neuritis. In 8 patients, the latency of visual evoked responses was normal after the resolution of clinical symptoms, and in a further 5 patients improvement in VER latency occurred although the response remained abnormal. In 17 patients, VER's abnormal and did not alter over the period of clinical recovery; in 4 patients there was a progressive increase in the latency of the VER's through both eyes although a satisfactory clinical recovery occurred. The frequency of histocompatibility antigens was similar in the group of ON patients to that in the normal population. Immunological function was normal in patients with ON as assessed by levels of immunoglobulins. T and B lymphocyte numbers and by lymphocyte blastogenesis in response to PHA and myelin basic protein. Three patients have developed multiple sclerosis, all of whom had either HLA-A3 or -B7 antigens; the clinical and electrophysiological pattern of recovery was different in each case.

In 14 patients with tuberculosis treated with ethambutol hydrochloride, pattern-reversal visual evoked potentials (VEPs) were recorded to monocular, whole-field stimulation before the commencement of treatment and one month and three months subsequently. In six subjects, the VEPs showed changes in the latency and amplitude of the P100 component at the one- or three-month interval. In three cases, the VEP changes reversed after cessation of treatment. In five of the six cases, changes were not associated with a change in visual function, as measured by clinical neuro-ophthalmologic examination. Our findings confirm the usefulness of VEPs in the detection of subclinical optic nerve disease and suggest their use in routine monitoring of ocular function in patients treated with ethambutol.

Nerve conduction studies were performed on 26 patients with polycythemia vera, 11 of whom had sensory symptoms in the extremities and 3 of whom had clinical signs of peripheral neuropathy. There was significant impairment of sensory conduction in the ulnar and sural nerves and mild slowing of motor conduction in the lateral popliteal nerve. Sural nerve biopsies were performed on three patients. The pathological findings, including teased fiber studies, were consistent with mild chronic axonal degeneration. There is an association between polycythemia vera and peripheral neuropathy.

Electrophysiological and pathological studies have been performed on three patients with recurrent focal swelling of the calf muscles simulating deep venous thrombosis, and in a patient with both cardiomyopathy and skeletal muscle disease. In all patients there were elevated CPK levels, histological evidence of an acute myopathy, heavy alcohol intake prior to the development of symptoms, and improvement in hospital with the cessation of alcohol consumption. These patients illustrate a form of alcoholic muscle disease which may be more common than generally realised.

Journal Article ABNORMALITIES OF INSULIN SECRETION IN DYSTROPHIA MYOTONICA Get access J. C. WALSH, J. C. WALSH From The Department of Medicine, University of Sydney and Royal Prince Alfred HospitalSydney Search for other works by this author on: Oxford Academic PubMed Google Scholar J. R. TURTLE, J. R. TURTLE From The Department of Medicine, University of Sydney and Royal Prince Alfred HospitalSydney Search for other works by this author on: Oxford Academic PubMed Google Scholar SUSAN MILLER, SUSAN MILLER From The Department of Medicine, University of Sydney and Royal Prince Alfred HospitalSydney Search for other works by this author on: Oxford Academic PubMed Google Scholar J. G. MCLEOD J. G. MCLEOD From The Department of Medicine, University of Sydney and Royal Prince Alfred HospitalSydney Search for other works by this author on: Oxford Academic PubMed Google Scholar Brain, Volume 93, Issue 4, 1970, Pages 731–742, https://doi.org/10.1093/brain/93.4.731 Published: 01 October 1970 Article history Received: 04 February 1970 Published: 01 October 1970