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BICYCLE SADDLES AND TORSION OF THE TESTIS
1149 which has recently been recommended2and which is based on the slopes of the mean-values line. The slopes from Denson’s data are 1 - 00 in group A and 1 - 2in group B, giving an even greater difference than our ratio n. The calibration of thromboplastins might be influenced by the degree of anticoagulation of the plasma samples.We have always believed calibrations between thromboplastins sshould be based on plasma samples within the therapeutic range of oral anticoagulant dosage. The plasmas used in our calibration exercises were obtained from our out-patients who have been stabilised on
long-term therapy. In the accompanying figure, the serial mean values of ratio ii (the prothrombin-time ratio of 67/40 divided by the prothrombin-time ratio of 69/223) and the slope of the meanvalues line2 of the degradation studies are plotted. These include two later correlations not reported in our paper. It appears that mean ratio n is more reproducible than the slope of the mean-values line. Therefore, if the calibration is influenced by the plasma samples used, our method (using ratios i and n) appears to be more reliable than the mean values method. We are thus reassured that our statistical evaluation has been appropriate and the conclusions valid. National
(U.K.) Reference Laboratory for Anticoagulant Reagents and Control, Withington Hospital, Manchester M20 8LR
K. F. YEE J. M. THOMSON L. POLLER
to be changed for a boy who has had his testes fixed by operation. If pain develops immediately the spermatic cord twists the mishap occurred whilst cycling in only one of their cases, and this merely confirms previous observations that torsion may be induced by strenuous activity. The testes in all these boys were almost certainly restrained by fashionable tight briefs making it unlikely that cycling movements would produce sufficient
needs
rotation to cause torsion. About half the cases of torsion occur in bed and wake the boy from sleep. The most likely common factor to explain torsion developing during activity and sleep is that contraction of the spirally placed fibres of the cremaster muscle produces the twisting. Torsion during cycling can then be attributed to cremaster spasm induced by exertion or to a vigorous cramasteric reflex from cold air penetrating clothing. The last three cases of torsion I have seen all occurred during sleep in boys with obvious bilateral so-called inverted or horizontally placed testes. If doctors who do routine medical examinations on schoolboys would learn to recognise this predisposing condition these cases could be referred for fixation before torsion occurred. Department of Anæsthetics,
Dryburn Hospital,
O. B. GIBSON
Durham DH1 5TW
SURGERY OR SCLEROTHERAPY FOR VARICOSE VEINS BICYCLE SADDLES AND TORSION OF THE TESTIS
SiR,-Dr Jackson and Dr Craft (May 6, p. 983) associate cases in the last few years of torsion of the testis in boys aged 13-15 from the Newcastle area with the riding of racing bicycles with narrow saddles. What percentage of the total number of such cases do these 5 represent, were they related to one particular brand of saddle, what evidence supports their explanation of the mechanism of the injury, and why has the injury not been seen in other age-groups? If injury due to this cause is widespread the observation that three of the five patients had had the offending cycle for only a few days is probably relevant. The past 20 years have seen the introduction of saddles constructed of a thermoplastic body
five
supporting wire frame. Some have a bonded leather cover with synthetic padding beneath the leather, and these are the saddles that most professional and other competitive cyclists use. On this type of saddle I have ridden over 470 miles in 24 hours on several occasions without undue discomfort and as a medical officer to world championship, professional, and amateur multistage races, I never saw a case of torsion of the testis due to cycling. It is possible that these boys were riding on cheap saddles designed to meet a price rather than an anatomical need, and they may have had the saddle at an unsuitable angle or height. If this was so the prevention of the problem lies in obtaining cycles from dealers who can give personal advice, and not just a salesman or mail-order agent. There are several problems caused by racing-cycle saddles amongst professional riders (who often do 500-600 miles per week) but these are mainly of chafing, infection of hair follicles, and transient urethritis due to bruising. Female competitors have many more problems and the design of a suitable saddle for them is being investigated by the Women’s Cycle Racing Association. on a
British Nuclear Fuels Ltd.,
Salwick, Preston, Lancashire PR4 0XJ
R. C. GOODFELLOW
SIR Torsion of the testis has been reported in connection with a variety of activities or even during complete inactivity, but I doubt if Dr Jackson and Dr Craft (May 6, p. 983) have established a relationship between bicycle saddles and this complaint. And even if they have I fail to see why the saddle
SiR,—Iwas most interested to read the third report of the Cardiff vein trial (April 29, p. 921) which gives the five-year results. However, this follow-up study of only 214 patients is primarily concerned with cost. The follow-up examinations are not detailed, other than those of 16 patients examined by two medical students. The vein problems treated are not classified, and there are no details of the surgical treatment other than the estimated cost. 3 serious complications in such a small series is unexpected and unfortunate; since the risk with either method of treatment is very small, this factor should not influence the choice of method. The other two conclusions are contradictory. If "the longterm clinical outcome is of overriding importance in deciding on the treatment" the economic costs should not be considered but can be kept down by using the indicated method efficiently. Although these five-year findings are similar to the six-year result of the St Mary’s trial these workers do not report the effect of treatment in relation to the type of vein problem. Fig. 2 of my paper! suggests conclusions very different from the overall impression and shows that the results of the two methods must be related to the type of vein problem. The ten-year results of the St Mary’s trial emphasise the need for selection and show that long and short saphenousvein incompetence treated by sclerotherapy may achieve excellent results for many years but that the problem will have recurred within ten years.2 Vein patients are best dealt with in special clinics and not at the end of a busy surgical outpatient session. When there is proximal valvular incompetence of either the long or short saphenous vein, surgery is indicated, but this should be minor and require no more than an overnight stay; other vein problems are best dealt with by sclerotherapy. When the two methods are combined the proximal lesion should be dealt with first. The proper treatment of vein problems requires careful and accurate assessment with precise planning and execution of treatment. Vein Clinic, St Mary’s Hospital, London W2 1NY 1. Hobbs, J. T. Archs Surg. 1974, 109, 793. 2. Hobbs, J. T. Paper read at VIth World Buenos Aires in October, 1977.
JOHN T. HOBBS Congress
of
Phlebology,
held in
long-term therapy. In the accompanying figure, the serial mean values of ratio ii (the prothrombin-time ratio of 67/40 divided by the prothrombin-time ratio of 69/223) and the slope of the meanvalues line2 of the degradation studies are plotted. These include two later correlations not reported in our paper. It appears that mean ratio n is more reproducible than the slope of the mean-values line. Therefore, if the calibration is influenced by the plasma samples used, our method (using ratios i and n) appears to be more reliable than the mean values method. We are thus reassured that our statistical evaluation has been appropriate and the conclusions valid. National
(U.K.) Reference Laboratory for Anticoagulant Reagents and Control, Withington Hospital, Manchester M20 8LR
K. F. YEE J. M. THOMSON L. POLLER
to be changed for a boy who has had his testes fixed by operation. If pain develops immediately the spermatic cord twists the mishap occurred whilst cycling in only one of their cases, and this merely confirms previous observations that torsion may be induced by strenuous activity. The testes in all these boys were almost certainly restrained by fashionable tight briefs making it unlikely that cycling movements would produce sufficient
needs
rotation to cause torsion. About half the cases of torsion occur in bed and wake the boy from sleep. The most likely common factor to explain torsion developing during activity and sleep is that contraction of the spirally placed fibres of the cremaster muscle produces the twisting. Torsion during cycling can then be attributed to cremaster spasm induced by exertion or to a vigorous cramasteric reflex from cold air penetrating clothing. The last three cases of torsion I have seen all occurred during sleep in boys with obvious bilateral so-called inverted or horizontally placed testes. If doctors who do routine medical examinations on schoolboys would learn to recognise this predisposing condition these cases could be referred for fixation before torsion occurred. Department of Anæsthetics,
Dryburn Hospital,
O. B. GIBSON
Durham DH1 5TW
SURGERY OR SCLEROTHERAPY FOR VARICOSE VEINS BICYCLE SADDLES AND TORSION OF THE TESTIS
SiR,-Dr Jackson and Dr Craft (May 6, p. 983) associate cases in the last few years of torsion of the testis in boys aged 13-15 from the Newcastle area with the riding of racing bicycles with narrow saddles. What percentage of the total number of such cases do these 5 represent, were they related to one particular brand of saddle, what evidence supports their explanation of the mechanism of the injury, and why has the injury not been seen in other age-groups? If injury due to this cause is widespread the observation that three of the five patients had had the offending cycle for only a few days is probably relevant. The past 20 years have seen the introduction of saddles constructed of a thermoplastic body
five
supporting wire frame. Some have a bonded leather cover with synthetic padding beneath the leather, and these are the saddles that most professional and other competitive cyclists use. On this type of saddle I have ridden over 470 miles in 24 hours on several occasions without undue discomfort and as a medical officer to world championship, professional, and amateur multistage races, I never saw a case of torsion of the testis due to cycling. It is possible that these boys were riding on cheap saddles designed to meet a price rather than an anatomical need, and they may have had the saddle at an unsuitable angle or height. If this was so the prevention of the problem lies in obtaining cycles from dealers who can give personal advice, and not just a salesman or mail-order agent. There are several problems caused by racing-cycle saddles amongst professional riders (who often do 500-600 miles per week) but these are mainly of chafing, infection of hair follicles, and transient urethritis due to bruising. Female competitors have many more problems and the design of a suitable saddle for them is being investigated by the Women’s Cycle Racing Association. on a
British Nuclear Fuels Ltd.,
Salwick, Preston, Lancashire PR4 0XJ
R. C. GOODFELLOW
SIR Torsion of the testis has been reported in connection with a variety of activities or even during complete inactivity, but I doubt if Dr Jackson and Dr Craft (May 6, p. 983) have established a relationship between bicycle saddles and this complaint. And even if they have I fail to see why the saddle
SiR,—Iwas most interested to read the third report of the Cardiff vein trial (April 29, p. 921) which gives the five-year results. However, this follow-up study of only 214 patients is primarily concerned with cost. The follow-up examinations are not detailed, other than those of 16 patients examined by two medical students. The vein problems treated are not classified, and there are no details of the surgical treatment other than the estimated cost. 3 serious complications in such a small series is unexpected and unfortunate; since the risk with either method of treatment is very small, this factor should not influence the choice of method. The other two conclusions are contradictory. If "the longterm clinical outcome is of overriding importance in deciding on the treatment" the economic costs should not be considered but can be kept down by using the indicated method efficiently. Although these five-year findings are similar to the six-year result of the St Mary’s trial these workers do not report the effect of treatment in relation to the type of vein problem. Fig. 2 of my paper! suggests conclusions very different from the overall impression and shows that the results of the two methods must be related to the type of vein problem. The ten-year results of the St Mary’s trial emphasise the need for selection and show that long and short saphenousvein incompetence treated by sclerotherapy may achieve excellent results for many years but that the problem will have recurred within ten years.2 Vein patients are best dealt with in special clinics and not at the end of a busy surgical outpatient session. When there is proximal valvular incompetence of either the long or short saphenous vein, surgery is indicated, but this should be minor and require no more than an overnight stay; other vein problems are best dealt with by sclerotherapy. When the two methods are combined the proximal lesion should be dealt with first. The proper treatment of vein problems requires careful and accurate assessment with precise planning and execution of treatment. Vein Clinic, St Mary’s Hospital, London W2 1NY 1. Hobbs, J. T. Archs Surg. 1974, 109, 793. 2. Hobbs, J. T. Paper read at VIth World Buenos Aires in October, 1977.
JOHN T. HOBBS Congress
of
Phlebology,
held in