- Email: [email protected]
VIBRATION ARTHROGRAPHY
1356
undergo arthroscopy to exclude internal derangements for pain at the front of the knee and to confirm that there is no abnormality of the patellar surface or the synovial plicae. If the same reassurance can be given by a non-invasive outpatient technique, the benefits would be substantial. Other exciting possibilities include assessment of the results of meniscal reattachment, patellar shaving, tibial osteotomy, and joint debridement for osteoarthritis. Although it is hard VIBRATION ARTHROGRAPHY to estimate the full potential of vibration arthrography so SOUNDS emanating from within the knee have always early in its development, it seems likely to take its place been - important in clinical assessment of that joint. alongside other techniques in the investigation of knee Snapping, clicks, thuds, or bangs--descriptions which offer disorders. If it does nothing else, it should help to eliminate an indication of the pitch and duration of the sounds-are the surgical error of removing a normal meniscus. reported by patients, many of whom can localise the source of the sound within the knee. An English don likened the grating ’of his patellofemoral crepitus to "the rush of sea across shingle", while the less imaginative suffer from knees
masterly-in all but cases of terminal malignancy. The widespread recognition of massive haemoptysis as a life-threatening condition may reduce the number of deaths in otherwise fit and potentially curable patients.
full of "broken biscuits" or "crushed ice". Clinicians have come to associate crepitus with osteoarthritis, thuds with meniscal tears, and clicks at the front of the knee with anterior knee pain, but without a firm basis for these
assumptions. Despite their clinical value, it is only lately that modem technology has been brought to bear upon the investigation of joint sounds. McCoy and colleagues,! using an accelerometer instead of a stethoscope or microphone, have now investigated the vibration signals coming from normal and abnormal joints, and confirm their clinical relevance. Tom menisci emit a characteristic signal which can be localised
to
the affected compartment, and several other
signals, including physiological patellofemoral crepitus, a patellar click, and a plica signal have been identified. The examination, which involves attaching three small devices to the skin over the knee, is non-invasive and can be conducted on outpatients more simply and quickly than either arthrography or arthroscopy. At this stage of its development, the technique still has limitations. False-negatives were found by McCoy et al in patients with an effusion or a locked bucket-handle fragment of meniscus, and a test which cannot detect such gross lesions has obvious shortcomings. The recordings were made between 0 and 90° of simple flexion, which makes it impossible to reproduce the traditional McMurray test, whatever the value of that test may be. Apart from this, clinical examination can determine whether the click is painful, whether the patient is apprehensive when the knee is stressed, and whether the click is altered by different varus, valgus, or rotational strains. It is unfair to compare vibration arthrography, as McCoy et al have called their examination, with established techniques that assess different aspects of the joint. Radionuclide scans will identify areas of increased metabolic activity within bone while double-contrast arthrography can outline the shape of intra-articular structures. Arthroscopy allows structures within the knee to be lifted, probed, or pulled; at the same time their vascularity can be assessed, and tissue removed. In time, vibration arthrography will doubtless be able to offer more than at present, but it is already possible to see areas in which the technique will be particularly useful. Anterior knee pain probably offers the greatest opportunity. Many patients, usually young and anxious, 1. McCoy
GF, McCrea JD, Beverland DE, Kemohan GW, Mollan RAB. Vibration as a diagnostic aid in diseases of the knee. J Bone Joint Surg 1987;
arthrography
69B: 288-93.
HYPOPROLACTINAEMIA THE importance of human prolactin in the initiation and maintenance of lactation is well recognised. Does the hormone also play an essential part in the development of puberty and in the control of cyclical ovarian function? Are there optimum concentrations or can there be too much or too little secreted? To answer these questions much information has come from studies on women with hyperprolactinaemia; reports of isolated prolactin deficiency, however, other than that following operation or
medication, are rare. There is in-vitro evidence that excessive concentrations of prolactin introduced into culture medium inhibit steroid production from human ovarian tissue.12 In women with hyperprolactinaemia who do not ovulate such direct action of prolactin seems less likely since they respond to gonadotropin therapy3-5 and to pulsatile gonadotropin releasing hormone treatment,6 produce normal quantities of oestrogen and progesterone, conceive, and bear children. It is more likely that in hyperprolactinaemia ovulation fails because the normal positive feedback of oestrogen on luteinising hormone is blocked and the negative feedback effect on follicle-stimulating hormone is exaggerated.’7 In-vitro studies also indicate that a small amount of prolactin is essential for the normal production of progesterone.1 This finding is consistent with the observation that when prolactin in normal women is suppressed by bromocriptine therapy, luteal phases are deficient.8 Information on this aspect of prolactin physiology is not plentiful: there are few reports of hypoprolactinaemia, except in patients who have undergone 1. McNatty KP, Sawers RS, McNeilly AS. A possible role for prolactin in control of steroid secretion by the human graafian follicle. Nature 1974; 250: 653-55 2 Demura R, Ono M, Demura H, Shizume K, Oouchi H. Prolactin directly inhibits .basal as well as gonadotropin-stimulated secretion of progesterone and 17&bgr;estradiol in the human ovary. J Clin Endocrinol Metab 1982, 54: 1246-50 3. Del Pozo E, Varga L, Schulz KD, et al Pituitary and ovarian response patterns to stimulation in the post partum and in galactorrhea-amenorrhea. Obstet Gynecol 1975, 46: 539-43. 4. Archer DF, Josimovich JB. Ovarian response to exogenous gonadotropins in women with elevated serum prolactin. Obstet Gynecol 1976; 48: 155-57. 5 Butt WR. The diagnosis of ovulatory disorders In: Crighton B, Haynes NB, Foxcroft GR, Lamming GE, eds The control of ovulation in the human. London. Butterworth, 1978. 357-71. 6. Poison DW, Sagle M, Mason HD, Adams J, Jacobs HS, Franks S Ovulation and normal luteal function during LHRH treatment of women with hyperprolactinaemic amenorrhoea Clin Endocrinol 1986, 24: 531-37. 7 London DR, Glass MR, Shaw RW, Butt WR, Logan Edwards R. The modulation by ovarian hormones of gonadotrophin release in hyperprolactinaemic women In Crosignani PG, Robyn C, eds. Prolactin and human reproduction London Academic Press, 1977. 119-24 E, Wyss H, Leucranfan I, Obdensky W, Varga L In. Crosignani PG, Mishell O, eds Ovulation in the human. London: Academic Press, 1976 297-99
8. Del Pozo
undergo arthroscopy to exclude internal derangements for pain at the front of the knee and to confirm that there is no abnormality of the patellar surface or the synovial plicae. If the same reassurance can be given by a non-invasive outpatient technique, the benefits would be substantial. Other exciting possibilities include assessment of the results of meniscal reattachment, patellar shaving, tibial osteotomy, and joint debridement for osteoarthritis. Although it is hard VIBRATION ARTHROGRAPHY to estimate the full potential of vibration arthrography so SOUNDS emanating from within the knee have always early in its development, it seems likely to take its place been - important in clinical assessment of that joint. alongside other techniques in the investigation of knee Snapping, clicks, thuds, or bangs--descriptions which offer disorders. If it does nothing else, it should help to eliminate an indication of the pitch and duration of the sounds-are the surgical error of removing a normal meniscus. reported by patients, many of whom can localise the source of the sound within the knee. An English don likened the grating ’of his patellofemoral crepitus to "the rush of sea across shingle", while the less imaginative suffer from knees
masterly-in all but cases of terminal malignancy. The widespread recognition of massive haemoptysis as a life-threatening condition may reduce the number of deaths in otherwise fit and potentially curable patients.
full of "broken biscuits" or "crushed ice". Clinicians have come to associate crepitus with osteoarthritis, thuds with meniscal tears, and clicks at the front of the knee with anterior knee pain, but without a firm basis for these
assumptions. Despite their clinical value, it is only lately that modem technology has been brought to bear upon the investigation of joint sounds. McCoy and colleagues,! using an accelerometer instead of a stethoscope or microphone, have now investigated the vibration signals coming from normal and abnormal joints, and confirm their clinical relevance. Tom menisci emit a characteristic signal which can be localised
to
the affected compartment, and several other
signals, including physiological patellofemoral crepitus, a patellar click, and a plica signal have been identified. The examination, which involves attaching three small devices to the skin over the knee, is non-invasive and can be conducted on outpatients more simply and quickly than either arthrography or arthroscopy. At this stage of its development, the technique still has limitations. False-negatives were found by McCoy et al in patients with an effusion or a locked bucket-handle fragment of meniscus, and a test which cannot detect such gross lesions has obvious shortcomings. The recordings were made between 0 and 90° of simple flexion, which makes it impossible to reproduce the traditional McMurray test, whatever the value of that test may be. Apart from this, clinical examination can determine whether the click is painful, whether the patient is apprehensive when the knee is stressed, and whether the click is altered by different varus, valgus, or rotational strains. It is unfair to compare vibration arthrography, as McCoy et al have called their examination, with established techniques that assess different aspects of the joint. Radionuclide scans will identify areas of increased metabolic activity within bone while double-contrast arthrography can outline the shape of intra-articular structures. Arthroscopy allows structures within the knee to be lifted, probed, or pulled; at the same time their vascularity can be assessed, and tissue removed. In time, vibration arthrography will doubtless be able to offer more than at present, but it is already possible to see areas in which the technique will be particularly useful. Anterior knee pain probably offers the greatest opportunity. Many patients, usually young and anxious, 1. McCoy
GF, McCrea JD, Beverland DE, Kemohan GW, Mollan RAB. Vibration as a diagnostic aid in diseases of the knee. J Bone Joint Surg 1987;
arthrography
69B: 288-93.
HYPOPROLACTINAEMIA THE importance of human prolactin in the initiation and maintenance of lactation is well recognised. Does the hormone also play an essential part in the development of puberty and in the control of cyclical ovarian function? Are there optimum concentrations or can there be too much or too little secreted? To answer these questions much information has come from studies on women with hyperprolactinaemia; reports of isolated prolactin deficiency, however, other than that following operation or
medication, are rare. There is in-vitro evidence that excessive concentrations of prolactin introduced into culture medium inhibit steroid production from human ovarian tissue.12 In women with hyperprolactinaemia who do not ovulate such direct action of prolactin seems less likely since they respond to gonadotropin therapy3-5 and to pulsatile gonadotropin releasing hormone treatment,6 produce normal quantities of oestrogen and progesterone, conceive, and bear children. It is more likely that in hyperprolactinaemia ovulation fails because the normal positive feedback of oestrogen on luteinising hormone is blocked and the negative feedback effect on follicle-stimulating hormone is exaggerated.’7 In-vitro studies also indicate that a small amount of prolactin is essential for the normal production of progesterone.1 This finding is consistent with the observation that when prolactin in normal women is suppressed by bromocriptine therapy, luteal phases are deficient.8 Information on this aspect of prolactin physiology is not plentiful: there are few reports of hypoprolactinaemia, except in patients who have undergone 1. McNatty KP, Sawers RS, McNeilly AS. A possible role for prolactin in control of steroid secretion by the human graafian follicle. Nature 1974; 250: 653-55 2 Demura R, Ono M, Demura H, Shizume K, Oouchi H. Prolactin directly inhibits .basal as well as gonadotropin-stimulated secretion of progesterone and 17&bgr;estradiol in the human ovary. J Clin Endocrinol Metab 1982, 54: 1246-50 3. Del Pozo E, Varga L, Schulz KD, et al Pituitary and ovarian response patterns to stimulation in the post partum and in galactorrhea-amenorrhea. Obstet Gynecol 1975, 46: 539-43. 4. Archer DF, Josimovich JB. Ovarian response to exogenous gonadotropins in women with elevated serum prolactin. Obstet Gynecol 1976; 48: 155-57. 5 Butt WR. The diagnosis of ovulatory disorders In: Crighton B, Haynes NB, Foxcroft GR, Lamming GE, eds The control of ovulation in the human. London. Butterworth, 1978. 357-71. 6. Poison DW, Sagle M, Mason HD, Adams J, Jacobs HS, Franks S Ovulation and normal luteal function during LHRH treatment of women with hyperprolactinaemic amenorrhoea Clin Endocrinol 1986, 24: 531-37. 7 London DR, Glass MR, Shaw RW, Butt WR, Logan Edwards R. The modulation by ovarian hormones of gonadotrophin release in hyperprolactinaemic women In Crosignani PG, Robyn C, eds. Prolactin and human reproduction London Academic Press, 1977. 119-24 E, Wyss H, Leucranfan I, Obdensky W, Varga L In. Crosignani PG, Mishell O, eds Ovulation in the human. London: Academic Press, 1976 297-99
8. Del Pozo