Osteochondrosis is a developmental orthopedic disorder affecting the cartilage and bone in horses, typically occurring in young, growing animals. It involves the disruption of normal endochondral ossification, leading to the formation of lesions in the joint cartilage and subchondral bone. These lesions can result in joint pain, lameness, and reduced performance. Osteochondrosis is commonly observed in the stifle, hock, and fetlock joints of horses. Various factors, including genetics, nutrition, growth rate, and mechanical stress, are associated with its development. This page compiles peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and management of osteochondrosis in equine populations.
Vatistas NJ, Wright IM, Dyson SJ.Forty-eight horses with osteochondritic lesions of the femoropatellar joint were treated, 23 of them by an arthrotomy and 25 by arthroscopy. Follow-up information was obtained from either the owner or the referring veterinarian by telephone inquiry. There were no statistical differences between the groups of horses undergoing the two procedures with regard to age, sex, breed, the involvement of one or both limbs, the size of the lesion, and the duration of either the surgery or anaesthesia. However, the horses treated by an arthrotomy spent 14.5 days in hospital after the operation whereas tho...
Carlson CS, Cullins LD, Meuten DJ.The objectives of this study were to determine in horses 1) the ages at which viable cartilage canal vessels are present in the articular-epiphyseal cartilage complex of three predilection sites and one nonpredilection site of osteochondrosis (OC), 2) the prevalence of lesions of OC in these sites, and 3) whether there was an association of lesions of OC with necrotic cartilage canal blood vessels. The medial femoral condyle, lateral femoral trochlear ridge, and distal ends of the tibia and proximal phalanx were examined grossly, microradiographically, and histologically in 35 horses 18 months...
Nixon AJ, Pool RR.Osteochondral fragments from the axial proximoplantar/proximopalmar region of the proximal phalanx were removed from 38 joints in 30 horses. Ninety-three percent of the horses were Standardbreds, and 28 of the 30 had a low-grade lameness. All but 1 of the horses had hind limb involvement. A total of 43 fragments were removed. Most (71%) of the fragments involved the medial aspect of the joint and had to be dissected from a covering of synovial tissue. Histologically, the circumference of most fragments consisted of a transition zone at the attachment of the joint capsule, a region of nonarticu...
Grøndahl AM, Engeland A.The tarsocrural, metacarpophalangeal, and metatarsophalangeal joints of 753 Standardbred yearlings were radiographed. On the basis of radiographic findings, the horses were allotted into 4 groups. Group-1 horses had osteochondrosis in the tarsocrural joints. Group-2 horses had palmar/plantar bony fragments in the metacarpo- and metatarsophalangeal joints. Group-3 horses had radiographic changes in the metacarpo- and metatarsophalangeal joint region, such as bony fragments located at the dorsoproximal end of the proximal phalanx, osteochondrosis of the sagittal ridge of the third metacarpus/met...
Muttini A, Petrizzi L, Tinti A, Bertoluzza A.An investigation was carried out on most common synovial fluid parameters of normal and osteochondritic hocks of horses less than 12 months old in order to confirm the presence of an inflammatory process. Furthermore, a spectroscopic study was performed on synovial fluid from both normal and diseased hocks. A depolymerization of hyaluronic acid was demonstrated in synovial fluid from diseases joints, similar to that reported in human rheumatoid arthritis. A one month rest seem to normalize all parameters considered and in one joint, a return to normal infrared spectrum was demonstrated.
Tomizawa N, Nishimura R, Sasaki N, Hayashi Y, Senba H, Hara S, Kadosawa T, Takeuchi A.Morphological differences between cervical vertebrae were statistically analyzed in ataxic foals to clarify abnormal structural factors in the pathogenesis of this problem. At first, multiple regression analysis and cluster analysis were performed with 28 variables in C3-C7 of 39 control foals without lameness. As a result, there were no sex differences in the growth of all cervical vertebral sites, and the most suitable categorization of the age of the foals was 3 clusters of 8 months old or younger, 9-12 months old and 13 months old or older in any sites in the cervical vertebrae. Twenty-eig...
Kawcak CE, McIlwraith CW.The results of arthroscopic surgery in the treatment of osteochondral fragmentation of the proximodorsal aspect of the first phalanx and the influence of other fetlock joint lesions on prognosis were evaluated in 336 horses. Horses were classified as: 1) returning to previous use at the same or higher class of performance; 2) returning to previous use (regardless of class of performance); or 3) failing to return to previous use. Ninety-six horses (29%) had fragmentation alone; 140 horses (42%) had fragmentation and additional fetlock lesions, and 100 horses (29%) underwent concurrent carpal ar...
Nixon AJ.Arthroscopic examination of the hip joint was performed in mature and juvenile horses, using a lateral approach and standard or long instruments depending on body weight. Nine hip joints were examined in three cadavers and four anesthetized horses. The lateral, cranial, and caudal regions of the femoral head and acetabulum were accessible, and, after distraction of the limb, the ligament of the head of the femur and the acetabular notch were also visible. In small horses, the medial regions of the hip joint were visible but were inaccessible in larger horses. Iatrogenic injury to the sciatic n...
Howard RD, McIlwraith CW, Trotter GW, Powers BE, McFadden PR, Harwood FL, Amiel D.Bilateral osteochondral defects (10 mm2 x 3 mm deep) were created on the distal articular surface of the radial carpal bone of ten, 2- to 3-year-old horses. One defect of each horse was repaired, using a sternal cartilage autograft (treated), and the other was left untreated (control). The horses were exercised on a high-speed treadmill at incrementally increased speed and duration over the course of 12 months. Horses were evaluated arthroscopically at 6 to 7 weeks, and clinical examinations were conducted weekly at exercise. Twelve months after surgery, carpuses of each horse were radiographe...
Schneider RK, Ragle CA, Carter BG, Davis WE.Osteochondral fragments detected in the proximal interphalangeal joint in the pelvic limbs of 3 horses (2 Standardbreds and 1 Thoroughbred) caused joint enlargement and lameness. Fragments were removed by use of arthroscopy. Accurate placement of the arthroscope into the dorsal joint space was necessary to obtain an adequate view of the fragments. After surgery, 2 of the horses resumed racing without joint problems, and the third was in training to race. High-detail radiographs are necessary to detect osteochondral fragments in horses with joint enlargement or lameness localized to the proxima...
Beard WL, Bramlage LR, Schneider RK, Embertson RM.Medical records for 64 Thoroughbred and 45 Standardbred horses with osteochondrosis dissecans (OCD) of the tarsocrural joint that were treated by means of arthroscopic removal of the fragments before 2 years of age and before beginning racing were reviewed. Lesion site was recorded for all horses. The other foals from the dams of these surgically treated horses (siblings) were identified from mare progeny records. Racing data, including number of starts and money won during the 2- and 3-year-old racing years were obtained from the Jockey Club and the United States Trotting Association for affe...
Barr AR, Wotton SF, Dow SM, Waterman AE, Goodship AE, Duance VC.The effects of osteochondral defect location and post-operative walking exercise on structural repair and recovery of joint function were examined in the midcarpal joints of ponies. Functional recovery was monitored by measuring ground reaction forces using a force plate. Structural repair was evaluated histologically and by measuring the total collagen and uronic acid content and relative proportions of Type I and II collagen in the repair tissue. Central defects tended to cause a more marked functional disturbance but were repaired with fibrocartilage rather than fibrous tissue in 3 out of 6...
Dabareiner RM, Sullins KE, White NA.The clinical and radiographic progression, and arthroscopic findings for nine young horses (< 1 year of age) with femoropatellar osteochondrosis (OCD) are presented. Horses had a 2 to 12 week history of bilateral (8 horses) or unilateral (1 horse) hindlimb lameness. The most consistent clinical signs included femoropatellar joint distention and bilateral hindlimb lameness. At the onset of clinical signs, radiographic lesions were not present (4 horses) or subtle (5 horses), but were easily identified on radiographs taken 4 to 24 weeks later. Arthroscopic surgery was delayed until radiograph...
Grøndahl AM, Dolvik NI.Radiography of the tibiotarsal and metacarpo- and metatarsophalangeal joints was performed on 753 Standardbred trotters (6 to 21 months old) born in 1988. The surveyed population was drawn at random from all parts of Norway and represented about 60% of Standardbred trotters born the same year. Osteochondrosis in the tibiotarsal joint was diagnosed in 108 (14.3%) horses, and the prevalence of disease in progeny groups > 10 ranged from 0 to 69%. Bony fragments in the palmar/plantar portion of the metacarpo- and metatarsophalangeal joints were diagnosed in 89 (11.8%) horses, and the prevalence of...
Trostle SS, Dubielzig RR, Beck KA.Nine horses with clinical and radiographic findings of cervical vertebral malformation that were necropsied and examined using frozen cervical spinal cord cross sections were reviewed. Only cases with actual distortion of the spinal cord due to compression were selected. The goal of the study was to determine the morphologic features responsible for narrowing of the spinal canal and compression of the spinal cord. In individual cases, bony changes are associated with osteochondrosis and osteomyelitis of the dorsal articular facets and osteosclerosis of the dorsal cervical lamina. Soft tissue p...
Laws EG, Richardson DW, Ross MW, Moyer W.A retrospective study of 114 Standardbred horses diagnosed with osteochondrosis (OC) of the cranial intermediate ridge of the distal tibia was carried out, and their subsequent race records were compared with 456 control horses. Each OC-affected horse was compared with 4 horses randomly selected from a list of horses matched to it by year of birth, sex and sire. The horses with OC were treated by arthroscopic removal of osteochondral fragments (N = 58) or managed conservatively (N = 56). The clinical presentation of these two groups was similar, although joint effusion was a more common presen...
Kaneko M, Oikawa M, Yoshihara T.Pathomorphological analysis was performed on fractured bones of 470 race horses. The most common fracture site was the limb (98% of cases), and the majority of fractures were intra-articular. Focal osteochondral lesions consisting of osteochondrosis, osteonecrosis and osteosclerosis were observed frequently in fractured and non-fractured bones. In the fractured bones, the lesions frequently appeared in the vicinity of the fractured site. Under the influence of antecedent osteochondrosis from the young stage, osteosclerotic and osteonecrotic lesions may have been induced by immoderate exercise ...
Foland JW, McIlwraith CW, Trotter GW.Arthroscopic surgery for the treatment of osteochondritis dissecans was undertaken on 252 femoropatellar joints in 161 horses (82 Thoroughbreds, 39 Quarter Horses, 16 Arabians, 9 Warmbloods and 15 others of various breeds). There were 53 females and 108 males. Twenty-two horses were 1 year of age at the time of surgery, 68 were yearlings, 36 were 2-year-olds, 21 were 3-year-olds, and 14 were > or = 4 years old. Ninety-one had bilateral involvement and 70 had unilateral disease. Follow-up information was obtained on 134 horses, including 79 racehorses and 55 non-racehorses: 86 (64%) of these...
Caron JP, Bowker RM, Abhold RH, Toppin DS, Sonea IM, Vex KB.This preliminary study was designed to determine whether the neurotransmitter substance P was present in the middle carpal synovial membrane of the normal horse and whether the neuropeptide could be identified in the synovial fluid of normal horses and those with joint diseases. Immunocytochemistry on middle carpal synovial membrane biopsies from fresh cadavers was used to demonstrate substance P-containing neural elements. Substance P was most abundant in the subintimal portion of the membrane, with occasional filaments coursing via synovial fronds to the intimal portion. Radioimmunoassay tec...
Shoemaker RS, Bertone AL, Martin GS, McIlwraith CW, Roberts ED, Pechman R, Kearney MT.The effects of intra-articular administration of methylprednisolone acetate (MPA) on the healing of full-thickness osteochondral defects and on normal cartilage were evaluated in 8 horses. In group-1 horses (n = 4), a 1-cm-diameter, full-thickness defect was created bilaterally in the articular cartilage on the dorsal distal surface of the radial carpal bone. Cartilage defects were not created in group-2 horses (n = 4). One middle carpal joint was randomly selected in each horse (groups 1 and 2), and treated with an intra-articular injection of 100 mg of MPA, once a week for 4 treatments. Inje...
van Muiswinkel K.Based on three clinical cases, the history and the clinical and radiological aspects of osteochondrosis in horses are discussed. The prognosis, therapy and consequences with regard to athletic soundness and use for breeding are described.
Vail TB, McIlwraith CW.An intraarticular osteochondral chip fracture of the distal dorsolateral aspect of the right hind middle phalanx in a 4-year-old Dutch Warmblood gelding was removed arthroscopically. Accessibility and visibility of the fragment were excellent, and there was minimal soft tissue trauma.
Stick JA, Borg LA, Nickels FA, Peloso JG, Perau DL.An osteochondral fragment was removed from the caudal pouch of the lateral femorotibial joint in a 2-year-old Trakehner colt by use of arthroscopic surgery and a lateral approach. The approach to this aspect of the femorotibial joints was developed in another horse. The fragment was not attached and resembled an osteochondritis dissecans lesion. The intermittent lameness associated with the fragment resolved after surgical removal. A positive response to diagnostic anesthesia of the femorotibial joint in the absence of a confirmed diagnosis (following radiographic and arthroscopic evaluations ...
Desjardins MR, Hurtig MB, Palmer NC.The structural integrity of subchondral bone in fresh and frozen osteochondral autografts was investigated at month 3 in 10 horses. Two osteochondral autografts were harvested from the lateral aspect of the lateral trochlear ridge of the left talus in each of 10 anesthetized horses. Grafts were frozen in 7.5% DMSO. After 14 days, the thawed grafts were press-fitted into drill holes in the trochlear ridges of the right stifles. A fresh graft from the right hock was implanted in each left stifle. To control for the effects of surgery, a fresh graft was transferred from the right stifle to the le...
Scott EA, Snyder SP, Schmotzer WB, Pool R.Probable cause of fracture in a Paint gelding was a congenital bone defect involving the extensor process area of the right and left forelimb distal phalanges. Radiographically and histologically, subchondral bone cysts at the fracture lines were suspected. These cysts were thought to have developed in association with abnormal ossification centers at the extensor process areas of the third phalanx. Partial avulsion of weak extensor processes would then occur from natural forces exerted on these weakened bony prominences via the common digital extensor tendon. Support for osteochondrosis as a ...
Jeffcott LB.This paper reviews current developments in equine osteochondrosis complex and the clinical syndromes associated with it. Although the primary lesion has been defined as a failure of endochondral ossification, its definitive cause is unknown and appears to involve heredity, growth rate, nutrition, mineral imbalance, endocrinological dysfunction and biomechanical trauma. Despite the international importance of osteochondrosis in horses, surprisingly few controlled investigations have been performed on its pathogenesis. The studies that have been conducted suggest that local effects on differenti...
Freeman KP, Todhunter R, Lust G, Erb H, Rakestraw P, Slusher SH, Carroll B.Polychrome-stained equine synovial fluid specimens from 34 normal joints and 129 joints with clinical abnormalities were examined cytologically. The smears from joints with abnormalities were categorized as within normal limits (4.7%), slight abnormality (27.9%), proliferative synovitis (21.7%), neutrophilic pattern (20.2%), elongated cell pattern (10.1%), other moderate to marked abnormality (11.6%) and unsatisfactory (3.9%). Cytologic abnormalities that were not restricted to a single category included spindle cells, crystals, stellate cells and cartilage fragments. Multinucleate cells and m...
Lamb CR.Arthrography, tenography, and fistulography (or sinography) can provide additional information about the soft-tissue components of joints, tendon sheaths, and draining tracts, respectively. Arthrography is a valuable aid in the diagnosis of synovial masses, such as villonodular synovitis, and osteochondrosis. Tenography is particularly useful in evaluating chronic tendon sheath distention. Fistulography is an effective means of identifying acute traumatic damage to synovial structures and determining the cause and extent of draining tracts.
Stewart RH, Reed SM, Weisbrode SE.We compared the frequency and severity of osteochondrosis lesions in young Thoroughbred horses with cervical stenotic myelopathy (CSM) vs that in clinically normal Thoroughbreds of the same age. All lesions of the cervical vertebrae and appendicular skeleton were classified histologically as osteochondrosis or nonosteochondrosis and were measured for severity. Minimal sagittal diameter was significantly smaller in horses with CSM from C2 through C6; no difference was detected at C7. Severity of cervical vertebral osteochondrosis was greater in the horses with CSM, however frequency was not dif...
Houttu J.This paper presents the results of arthroscopic surgery in 42 Standardbred trotters and three Finnish horses. Forty-five horses were operated on. The age range was one to seven years; 73 per cent of the horses were three years old or younger. Horses showed a variety of clinical signs ranging from moderate to severe lameness at slow speeds, to obscure lameness manifesting only at high speeds. Synovial effusion of the fetlock joint was rare. In this series, 44 horses that had Type I fragments and one horse that had Type III fragments were operated on. Of the 45 horses operated on, 23 (51 per cen...
Marchant EA, Semevolos SA.The marginal transitional zone is peripherally located within the diarthrodial joint, and represents the interface of articular cartilage, periosteum, and the fibrous joint capsule. The purpose of this study is to characterize the protein expression of matrix and molecular regulators in the marginal transitional zone of foals having osteochondrosis (OC) compared to normal foals. Several families of proteins with known roles in cartilage and bone development are investigated, including matrix molecules, Wnt signaling, apoptotic factors and paracrine cell signaling molecules. Our results demonst...
Nyack B, Morgan JP, Pool R, Meagher D.Osteochondrosis of the shoulder joint in the horse was diagnosed radiographically in 54 shoulders of 38 horses. Clinical signs were those of an intermittent lameness characterized as a swinging leg shoulder lameness with pain elicited by extension, flexion or abduction of the limb. Diagnosis of shoulder lameness was supported by blocking the shoulder joint with local anesthetics. Radiographic changes consisted of: (1) alteration in the contour of the humeral head and glenoid cavity, (2) periarticular osteophyte formation, (3) sclerosis of the subchondral bone, and (4) bone cyst formation. The ...
Barclay WP, Foerner JJ, Phillips TN.Osteochondral fragmentation of the plantar aspect of the proximal phalanx was diagnosed as a cause of hind limb lameness in 19 horses. The lameness was evident at the upper levels of the horses' performance capabilities, and was isolated to the metatarsophalangeal joints by use of intra-articular or regional anesthesia. Fragments were surgically removed from 10 horses that later returned to full use. Seven horses were treated intra-articularly with polysulfated glycosaminoglycans or corticosteroids; only one horse was able to return to full use. One horse was retired from work at the time of d...
Bertuglia A, Pallante M, Pagliara E, Valle D, Bergamini L, Bollo E, Bullone M, Riccio B.Tarsocrural osteochondrosis (OCD) is a developmental orthopedic disease commonly affecting young Standardbreds, with different fragment localization and size. Clinically, it is characterized by variable synovial effusion in the absence of lameness, whose determinants are ill-defined. We hypothesized that localization and physical characteristics of the osteochondral fragments like dimensions, multifragmentation, and instability influence joint effusion and correlate with synovial markers of cartilage degradation and inflammation. Clinical data, synovial fluid and intact osteochondral fragments...
Van Cauter R, Caudron I, Lejeune JP, Rousset A, Serteyn D.Osteochondrosis dissecans is a particularly common developmental orthopaedic disorder in equines. Among its causes, the hereditary component is no longer a matter of debate, and, for several decades, the various studbooks for sport horses have been selecting stallions in order to limit the prevalence of this condition in the population. However, to our knowledge, no study has evaluated changes in the prevalence of osteochondrosis dissecans over time through longitudinal monitoring of a population of sport horses. The study presented here is part of a large screening programme for developmental...
Beck C, Hitchens PL, Whitton RC.Post-mortem studies have shown that fractures involving the metacarpophalangeal/metatarsophalangeal or fetlock joint are associated with focal areas of microdamage. Identification of computed tomography (CT) features consistent with microdamage and their association with fracture may aid in identification of horses at risk of fracture. Objective: To identify CT features associated with fracture of the metacarpophalangeal/metatarsophalangeal joint. Methods: Retrospective cohort study. Methods: Post-mortem CT images of 367 limbs from 157 Thoroughbred racehorses were graded for CT features. Multi...
Munoz Moran JA.This study was performed to evaluate the efficacy of intra-articular (IA) injections of a combination of platelet rich plasma (PRP) and hyaluronic acid (HA) on joint effusion following arthroscopic removal of OCD in the tarso-crural joint (TCJ) in young Andalusian horses. Methods: Forty Andalusian horses diagnosed with OCD of the distal intermediate ridge of the tibia (DIRT) were included in the study. Horses enrolled in this study had persisting synovial effusion after arthroscopic removal of OCD in the TCJ. A subjective semi-quantitative effusion score was adopted in the study to define the ...
Goldkuhl JEC, Zablotski Y, Sill V, Jahn W, Lorenz I, Brunk J, Gerlach K, Troillet A.Osteochondral fragment removal is commonly performed but there are little scientific data supporting this procedure in the absence of clinical signs. More information is needed to facilitate clinical decision-making regarding fragment removal of the metacarpo-/metatarsophalangeal joint. Objective: To assess prevalence of cartilage injury in the equine metacarpo-/metatarsophalangeal joint and its association to fragment size, location, age and lameness. Methods: Retrospective observational study. Methods: Clinical records, including radiographs of 823 metacarpo-/metatarsophalangeal joints (640 ...
Sønnichsen HV, Hansen SF.Osteochondrosis is a rapidly growing problem in the horse population and reports are frequent. Osteochondritis dissecans can in most cases be treated surgically, but reports on results are lacking. This paper reports the results of surgery of the tibiotarsal joint in 43 cases.
Reesink HL.Foals are susceptible to many of the same types of fractures as adult horses, often secondary to external sources of trauma. In addition, some types of fractures are specific to foals and occur routinely in horses under 1 year of age. These foal-specific fractures may be due to the unique musculoskeletal properties of the developing animal and may present with distinct clinical signs. Treatment plans and prognoses are tailored specifically to young animals. Common fractures not affecting the long bones in foals are discussed in this article, including osteochondral fragmentation, proximal ses...
van Muiswinkel K.Based on three clinical cases, the history and the clinical and radiological aspects of osteochondrosis in horses are discussed. The prognosis, therapy and consequences with regard to athletic soundness and use for breeding are described.
Skarbek A, Ramseyer A, Koch C, Van der Vekens E.An incidental osteochondritis dissecans (OCD) lesion was found in a left tarsus of a 3-year-old Freiberger stallion presented for a prepurchase examination. The lesion was best visualized on the dorsomedial-plantarolateral oblique and dorsoplantar projections. A standing computed tomographic examination confirmed a fragmentation of the dorsodistolateral aspect of the calcaneus. In suspected OCD lesions at the distal aspect of the talus or calcaneus, a dorsoplantar projection of the tarsus improves lesion localization and could be added to the standard radiographic protocol during OCD screening...