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New Zealand Veterinary Journal Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tnzv20
A degenerative joint disease in the horse R.S. Wyburn
a
a
Department of Veterinary Clinical Science , Massey University , Palmerston North Published online: 23 Feb 2011.
To cite this article: R.S. Wyburn (1977) A degenerative joint disease in the horse, New Zealand Veterinary Journal, 25:11, 321-335, DOI: 10.1080/00480169.1977.34445 To link to this article: http://dx.doi.org/10.1080/00480169.1977.34445
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
NEW ZEALAND VETERINARY JOURNAL
1977
Downloaded by [Chulalongkorn University] at 03:46 27 December 2014
N.Z.I'e/.J.25:321-22 & 335
A degenerative jOint disease in the horset R. s. Wyburn*
Osteochondritis dissecans has been reported in most of the domestic species and, in particular, in those breeds within the species where the emphasis has been on selection for large size and rapid maturity. It is seen most commonly on the epiphysis forming the main weight-bearing joints, the shoulder, elbow, hip, stifle and hock, In the horse the most commonly affected joint is the femero-patellar joint with the lesion occurring at the same site at approximately the mid-point of the lateral trochlear ridge. This paper is confined to a discussion of this condition. Twenty one cases of osteochondritis dissecans involving the femero-patellar joint have been seen at the Veterinary Faculty at Massey University over the eight years 1969-1976 and seventeen of these had bilateral involvement. The age of horses presented with osteochondritis dissecans of the stifle ranged from weanlings to early three-year-olds, with the majority being in the yearling early two-year-old group. The signs of lameness were commonly first noted just before the animals were to be presented for sale or when they were first put into work. In the older age group of horses there was some indication that the lesions had been present for some time but initially had not caused signs severe enough to draw attention to them. The histories that could be elicited from the owners of affected animals varied considerably. Most were of an insidious onset; vague. hind limb lameness which decreased or disappeared with exercise and was most obvious following a period of rest after exercise. Some cases. particularly in the older age group, were reported to have an intermittent locking of the stifle joint with the locking occurring in partial flexion, not in extension as with upward 'fixation of the patella. This locking occurred for the duration of two or three strides during fast work, frequently leaving the horse slightly lame for a few hours afterwards. Clinical examination of these horses was most unrewarding. The degree of lameness in general was only slight and, as it was commonly bilateral, it could be difficult to detect. The most striking feature was a low flight arc of the foot with the horse tending to slide its foot down onto the ground. In some cases it was possible to elicit a pain response on flexion of the stifle but, as flexion of the stifle is difficult without also causing flexion of
t *
321
Presented to the NZVA Annual Conference 1977. Department of Veterinary Clinical Science, Massey University. Palmerston North.
the hip and hock, this was not very helpful in isolating the lameness. In the majority of cases some distention of the medial femero-tibial joint-capsule could be felt between the middle and medial patella ligaments. This likely occurred because the femero-patella joint-space communicates with the medial fern oro-tibial joint-space, with only a small percentage of horses having a communication between femero-patella and lateral femero-tibialjoint-spaces. The diagnosis of osteochondritis dissecans of the stifle joint has to be confirmed radiologically. Ideally a lateral, oblique and P.A. radiograph of the stifle joint should be taken but, with most portable machines in use in general practice, it is not possible to get a diagnostic P.A. radiograph. Because of this, description of the lesions will be confined to those seen on the lateral oblique radiograph. To obtain a good quality lateral oblique radiograph of the stifle joint high-speed intensifying screens and film should be used. The cassette is slipped into the groin and pushed up as high as possible. Because of the shape of the inner aspect of the thigh the cassette, if pressed against it, will be angled caudally. The tube is then lined-up normal to the film, so that it is angled obliquely from slightly behind the lateral position, thus throwing the shadow of the lateral condyle in front of the medial condyle on the radiograph. The exposure factors required vary considerably from X-ray machine to X-ray machine but would be very approximately 75KV and l5MAS at a 75cm focus film distance. The lesion appears on the radiograph as an irregular defect on the lateral ridge of the trochlea (Figs. I and 2). The size of the lesion is variable but it commonly occurs at the same place, just distal to the shadow of the patella, if the plate is taken with the horse in the normal standing position. There is usually a sclerotic border to the bone defect and on some occasions further sclerotic-edged defects in the bone can be seen on the floor of the trochlear groove. In the older animals, the late two-year-olds and three-year-olds, there is often a detached piece of calcified cartilage floating free within the femero-patellar joint-space forming a "joint mouse". Similar lesions have been seen at other sites in the stifle joint: the distal aspect of the articular surface of the patella (2 cases); the lateral femoral condyle (one case); medial ridge of the trochlea (one case).
Continued next page
Downloaded by [Chulalongkorn University] at 03:46 27 December 2014
VOL. 25 NEW ZEALAND VETERINARY JOURNAL 322 The aetiology of osteochondritis dissecans remains obscure. It is thought to be due to repeated minor trauma to a particular region of bone which results in subchondral fractures and localised ischaemia. It has been shown to be more prevalent in individuals with a precocious development. In New Zealand we are very proud of our horses and put a big effort into turning them out well for the yearling sales. There is also the added incentive that big strong yearlings tend to fetch a higher price. Indeed the size of some of these animals as yearlings is somemwhat astounding. This high bodyweight and rapid maturity appears to predispose to osteochondritis dissecans. It is known that, in the dog, osteochondritis dissecans only occurs in the rapidly maturing large breeds and, in beef cattle, in the large rapidly maturing exotic breeds. Over and above this there is a distinct impression that, in the horse, osteochondritis dissecans occurs more in some years than others and occurs in the years when there is plenty of grass. It also appears to occur more on some properties than others which could also be related to the Fig. 2 Line drawing ofradiograph in Fig. 1. A-Medial ridge a/trochlea; amount of feed available but of course could equally well be . B-Iateral ridge of trochlea; C -defect in floor of trochlear groove; related to management, breeding or innumerable other factors. D-defect in lateral ridge of the trochlea. It could be suggested that there must be a physiological limit to holes in its bones or bubble nascent oxygen up its rectum! the size and rate of growth to the yearling stage and that we are The problem of arthritis involves a knowledge of the menow at, or very close, to this limit. tabolism of articular cartilage and synovial membrane with a statement of why it is perverted in arthritis. It involves an explanation of why trauma to articular cartilage in the form of normal activity does not evoke an inflammatory response in normal joints, but does in arthritis. We are just beginning to answer these questions, yet we have presumed enough in our knowledge to devise a multitude of cures. Arthritis is not yet a cureable disease so far as anything veterinary science can do about il. The basic facts are missing. Yet new cures are still being
Fig. 1 Lateral oblique radiograph of the stifle jOint of a yearling tho· roughbred showing defects in the lateral ridge ofthe trochlea and on the floor of the trochlear groove.
Before going on to discuss treatment I would like to misquote from Markowitz' book "Experimental surgery": "Veterinarians are prone to overtreat disease in spite of the Hippocratic maxim 'Primo non nocere' which for the less-educated of you means 'above all things do not harm'." Not, as some would have it. "There is no harm injust once"! Savage man respected nothing more than power. He used to worship his gods because they were strong, not because they were good and when he took sick he was reconciled to giving up all that was dearest to him so that they would relent and not exact his life. The treatment of arthritis seems to be in direct lineal descent from these ideas. Because of this atavistic trait, some of us still appear to feel that the tutelary goddess presiding over joints will surely be appeased if we blister our patients skin, if we stick hot irons into the tissues, if we chisel
described. When a speaker at a scientific meeting announces a new cure for arthritis the first question should be "Have you tried the Turkish Control?". "What" one may ask "is the Turkish Control?". Veterinarians are constantly being regaled by descriptions of new cures for old diseases. Tendon-transplant for sprained tendons, radiation therapy for carpitis, internal blistering with chemical solutions. It is possible that these are the modern equivalents of older, but hardly less barbarous, types of practices. An ancient horse doctor might well have said "First I bleeds them, then I physics them, next I sweats them and, if this don't work, I pewks them". Chronic ailments that have reached a stationary phase in their evolution are apt to be made better or worse by any procedure that violently affects the body. The intravenous injection of foreign protein for example. Many new cures described for old diseases have one thing in common - they inflict considerable physiological trauma on the body and every proposed new remedy should be scanned with this in mind. If one's suspicions cannot be allayed the remedy should be subject to the 'Turkish Control'. Subjects with the ailment under consideration are divided into three groups. The first group is left alone. The second group is suspended upside down by the heels and subjected to twenty heavy strokes with a bamboo cane. The third group is given the new remedy and the results of the three groups are compared. 'Turkish Control' is in the best Hippocratic tradition. It is better by far for the patient to receive twenty strokes of the cane than to be given an intravenous injection of rubbish, an injection of some noxious substance into its tissues or to be slowly poisoned by some curious organic chemical. A 'Turkish Control' has not been carried out with the treatment of these cases, so the results have not been adequately assessed. However, affected horses were divided into two groups for treatment. In the first group (cllll/jlllled Oil page 335)
1977
NEW ZEALAND VETERINARY JOVRNAL
(conlinued from page 322)
Downloaded by [Chulalongkorn University] at 03:46 27 December 2014
were those which only showed a defect in the bone and in the second group were those which had evidence of free bodies within the joint space. The first group were treated conservatively by suggesting box-rest with some decrease in food intake to reduce weight gain. In the human, restofthe affected joint is generally enforced by splinting across it. It would appear that in the horse two months imposed rest effects a cure. The word "appears" is used because most the young horses treated in this manner were subsequently sold and the vendors did not give permission for the new owners to be approached. However, it has been reported that many of these animals have subsequently campaigned
335
satisfactorily without showing any sign of hind limb lameness. The second group of horses with free bodies within the joint space were treated surgically. As most of the lesions were on the lateral aspect offemero-patellar joint the surgical approach was antero-lateral going between the lateral and middle patellar ligaments. The joint capsule was'incised and the free bodies removed. If they were not immediately visible they could be flushed out with normal saline. All the damaged cartilage was lifted out and the subchondral bone curretted until healthy bleeding bone was exposed. Subsequently the horses require at least nine months rest to allow the cartilage to regenerate. Horses treated in this manner have returned to racing without showing any signs of lameness.
New Zealand Veterinary Journal Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tnzv20
A degenerative joint disease in the horse R.S. Wyburn
a
a
Department of Veterinary Clinical Science , Massey University , Palmerston North Published online: 23 Feb 2011.
To cite this article: R.S. Wyburn (1977) A degenerative joint disease in the horse, New Zealand Veterinary Journal, 25:11, 321-335, DOI: 10.1080/00480169.1977.34445 To link to this article: http://dx.doi.org/10.1080/00480169.1977.34445
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
NEW ZEALAND VETERINARY JOURNAL
1977
Downloaded by [Chulalongkorn University] at 03:46 27 December 2014
N.Z.I'e/.J.25:321-22 & 335
A degenerative jOint disease in the horset R. s. Wyburn*
Osteochondritis dissecans has been reported in most of the domestic species and, in particular, in those breeds within the species where the emphasis has been on selection for large size and rapid maturity. It is seen most commonly on the epiphysis forming the main weight-bearing joints, the shoulder, elbow, hip, stifle and hock, In the horse the most commonly affected joint is the femero-patellar joint with the lesion occurring at the same site at approximately the mid-point of the lateral trochlear ridge. This paper is confined to a discussion of this condition. Twenty one cases of osteochondritis dissecans involving the femero-patellar joint have been seen at the Veterinary Faculty at Massey University over the eight years 1969-1976 and seventeen of these had bilateral involvement. The age of horses presented with osteochondritis dissecans of the stifle ranged from weanlings to early three-year-olds, with the majority being in the yearling early two-year-old group. The signs of lameness were commonly first noted just before the animals were to be presented for sale or when they were first put into work. In the older age group of horses there was some indication that the lesions had been present for some time but initially had not caused signs severe enough to draw attention to them. The histories that could be elicited from the owners of affected animals varied considerably. Most were of an insidious onset; vague. hind limb lameness which decreased or disappeared with exercise and was most obvious following a period of rest after exercise. Some cases. particularly in the older age group, were reported to have an intermittent locking of the stifle joint with the locking occurring in partial flexion, not in extension as with upward 'fixation of the patella. This locking occurred for the duration of two or three strides during fast work, frequently leaving the horse slightly lame for a few hours afterwards. Clinical examination of these horses was most unrewarding. The degree of lameness in general was only slight and, as it was commonly bilateral, it could be difficult to detect. The most striking feature was a low flight arc of the foot with the horse tending to slide its foot down onto the ground. In some cases it was possible to elicit a pain response on flexion of the stifle but, as flexion of the stifle is difficult without also causing flexion of
t *
321
Presented to the NZVA Annual Conference 1977. Department of Veterinary Clinical Science, Massey University. Palmerston North.
the hip and hock, this was not very helpful in isolating the lameness. In the majority of cases some distention of the medial femero-tibial joint-capsule could be felt between the middle and medial patella ligaments. This likely occurred because the femero-patella joint-space communicates with the medial fern oro-tibial joint-space, with only a small percentage of horses having a communication between femero-patella and lateral femero-tibialjoint-spaces. The diagnosis of osteochondritis dissecans of the stifle joint has to be confirmed radiologically. Ideally a lateral, oblique and P.A. radiograph of the stifle joint should be taken but, with most portable machines in use in general practice, it is not possible to get a diagnostic P.A. radiograph. Because of this, description of the lesions will be confined to those seen on the lateral oblique radiograph. To obtain a good quality lateral oblique radiograph of the stifle joint high-speed intensifying screens and film should be used. The cassette is slipped into the groin and pushed up as high as possible. Because of the shape of the inner aspect of the thigh the cassette, if pressed against it, will be angled caudally. The tube is then lined-up normal to the film, so that it is angled obliquely from slightly behind the lateral position, thus throwing the shadow of the lateral condyle in front of the medial condyle on the radiograph. The exposure factors required vary considerably from X-ray machine to X-ray machine but would be very approximately 75KV and l5MAS at a 75cm focus film distance. The lesion appears on the radiograph as an irregular defect on the lateral ridge of the trochlea (Figs. I and 2). The size of the lesion is variable but it commonly occurs at the same place, just distal to the shadow of the patella, if the plate is taken with the horse in the normal standing position. There is usually a sclerotic border to the bone defect and on some occasions further sclerotic-edged defects in the bone can be seen on the floor of the trochlear groove. In the older animals, the late two-year-olds and three-year-olds, there is often a detached piece of calcified cartilage floating free within the femero-patellar joint-space forming a "joint mouse". Similar lesions have been seen at other sites in the stifle joint: the distal aspect of the articular surface of the patella (2 cases); the lateral femoral condyle (one case); medial ridge of the trochlea (one case).
Continued next page
Downloaded by [Chulalongkorn University] at 03:46 27 December 2014
VOL. 25 NEW ZEALAND VETERINARY JOURNAL 322 The aetiology of osteochondritis dissecans remains obscure. It is thought to be due to repeated minor trauma to a particular region of bone which results in subchondral fractures and localised ischaemia. It has been shown to be more prevalent in individuals with a precocious development. In New Zealand we are very proud of our horses and put a big effort into turning them out well for the yearling sales. There is also the added incentive that big strong yearlings tend to fetch a higher price. Indeed the size of some of these animals as yearlings is somemwhat astounding. This high bodyweight and rapid maturity appears to predispose to osteochondritis dissecans. It is known that, in the dog, osteochondritis dissecans only occurs in the rapidly maturing large breeds and, in beef cattle, in the large rapidly maturing exotic breeds. Over and above this there is a distinct impression that, in the horse, osteochondritis dissecans occurs more in some years than others and occurs in the years when there is plenty of grass. It also appears to occur more on some properties than others which could also be related to the Fig. 2 Line drawing ofradiograph in Fig. 1. A-Medial ridge a/trochlea; amount of feed available but of course could equally well be . B-Iateral ridge of trochlea; C -defect in floor of trochlear groove; related to management, breeding or innumerable other factors. D-defect in lateral ridge of the trochlea. It could be suggested that there must be a physiological limit to holes in its bones or bubble nascent oxygen up its rectum! the size and rate of growth to the yearling stage and that we are The problem of arthritis involves a knowledge of the menow at, or very close, to this limit. tabolism of articular cartilage and synovial membrane with a statement of why it is perverted in arthritis. It involves an explanation of why trauma to articular cartilage in the form of normal activity does not evoke an inflammatory response in normal joints, but does in arthritis. We are just beginning to answer these questions, yet we have presumed enough in our knowledge to devise a multitude of cures. Arthritis is not yet a cureable disease so far as anything veterinary science can do about il. The basic facts are missing. Yet new cures are still being
Fig. 1 Lateral oblique radiograph of the stifle jOint of a yearling tho· roughbred showing defects in the lateral ridge ofthe trochlea and on the floor of the trochlear groove.
Before going on to discuss treatment I would like to misquote from Markowitz' book "Experimental surgery": "Veterinarians are prone to overtreat disease in spite of the Hippocratic maxim 'Primo non nocere' which for the less-educated of you means 'above all things do not harm'." Not, as some would have it. "There is no harm injust once"! Savage man respected nothing more than power. He used to worship his gods because they were strong, not because they were good and when he took sick he was reconciled to giving up all that was dearest to him so that they would relent and not exact his life. The treatment of arthritis seems to be in direct lineal descent from these ideas. Because of this atavistic trait, some of us still appear to feel that the tutelary goddess presiding over joints will surely be appeased if we blister our patients skin, if we stick hot irons into the tissues, if we chisel
described. When a speaker at a scientific meeting announces a new cure for arthritis the first question should be "Have you tried the Turkish Control?". "What" one may ask "is the Turkish Control?". Veterinarians are constantly being regaled by descriptions of new cures for old diseases. Tendon-transplant for sprained tendons, radiation therapy for carpitis, internal blistering with chemical solutions. It is possible that these are the modern equivalents of older, but hardly less barbarous, types of practices. An ancient horse doctor might well have said "First I bleeds them, then I physics them, next I sweats them and, if this don't work, I pewks them". Chronic ailments that have reached a stationary phase in their evolution are apt to be made better or worse by any procedure that violently affects the body. The intravenous injection of foreign protein for example. Many new cures described for old diseases have one thing in common - they inflict considerable physiological trauma on the body and every proposed new remedy should be scanned with this in mind. If one's suspicions cannot be allayed the remedy should be subject to the 'Turkish Control'. Subjects with the ailment under consideration are divided into three groups. The first group is left alone. The second group is suspended upside down by the heels and subjected to twenty heavy strokes with a bamboo cane. The third group is given the new remedy and the results of the three groups are compared. 'Turkish Control' is in the best Hippocratic tradition. It is better by far for the patient to receive twenty strokes of the cane than to be given an intravenous injection of rubbish, an injection of some noxious substance into its tissues or to be slowly poisoned by some curious organic chemical. A 'Turkish Control' has not been carried out with the treatment of these cases, so the results have not been adequately assessed. However, affected horses were divided into two groups for treatment. In the first group (cllll/jlllled Oil page 335)
1977
NEW ZEALAND VETERINARY JOVRNAL
(conlinued from page 322)
Downloaded by [Chulalongkorn University] at 03:46 27 December 2014
were those which only showed a defect in the bone and in the second group were those which had evidence of free bodies within the joint space. The first group were treated conservatively by suggesting box-rest with some decrease in food intake to reduce weight gain. In the human, restofthe affected joint is generally enforced by splinting across it. It would appear that in the horse two months imposed rest effects a cure. The word "appears" is used because most the young horses treated in this manner were subsequently sold and the vendors did not give permission for the new owners to be approached. However, it has been reported that many of these animals have subsequently campaigned
335
satisfactorily without showing any sign of hind limb lameness. The second group of horses with free bodies within the joint space were treated surgically. As most of the lesions were on the lateral aspect offemero-patellar joint the surgical approach was antero-lateral going between the lateral and middle patellar ligaments. The joint capsule was'incised and the free bodies removed. If they were not immediately visible they could be flushed out with normal saline. All the damaged cartilage was lifted out and the subchondral bone curretted until healthy bleeding bone was exposed. Subsequently the horses require at least nine months rest to allow the cartilage to regenerate. Horses treated in this manner have returned to racing without showing any signs of lameness.
