S t i f l e D i s o rd e r s Cranial Cruciate Ligament, Meniscus, Upward Fixation of the Patella Rebecca Pentecost,
DVM, MS,
Andrew Niehaus,
DVM, MS*
KEYWORDS Cattle Stifle Lameness Cranial cruciate ligament Meniscus Upward fixation of the patella KEY POINTS Stifle injury is a major source of lameness and can be associated with significant production losses in cattle. Cranial cruciate ligament injury is a common cause of stifle lameness, and treatment options range from conservative management to ligament replacement techniques. Meniscal injury can occur in cattle and is most frequently associated with ligament damage (mainly medial collateral ligament injury). Intermittent upward fixation of the patella is a rare condition affecting cattle in North America but is associated with a good prognosis with accurate diagnosis and surgical intervention.
INTRODUCTION
Stifle injury or disease remains a major source of proximal hind limb lameness in cattle. Structures that are commonly affected include the cranial cruciate ligament (CrCL), the medial meniscus, and the collateral ligaments. Osteoarthritis is a common sequela of a primary traumatic injury or degenerative breakdown of one of these structures. Economic losses associated with stifle disease are related to increased recumbency, decreased feed intake, decreased milk production, loss of muscle mass in the affected limb, conception failure in cows, and reluctance to mount in bulls.1 RELEVANT ANATOMY
The bovine stifle is composed of the femoropatellar, medial femorotibial, and lateral femorotibial joints. Communication exists between the femoropatellar and medial
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon Tharp Street, Columbus, OH 43210, USA * Corresponding author. E-mail address: [email protected] Vet Clin Food Anim 30 (2014) 265–281 http://dx.doi.org/10.1016/j.cvfa.2013.11.008 vetfood.theclinics.com 0749-0720/14/$ – see front matter Ó 2014 Elsevier Inc. All rights reserved.
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femorotibial joints in 100% of stifles and between the medial and lateral femorotibial joints in 65% of stifles.2 Similar to the horse, the bovine patella has a tendinous attachment to the quadriceps apparatus proximally and connects distally to the tibial crest via 3 separate ligaments: the medial, middle, and lateral patellar ligaments. The lateral patellar ligament is continuous with the tendon of the biceps femoris muscle. The cruciate ligaments are intra-articular and extrasynovial and provide rotational and craniocaudal support to the stifle.3 The CrCL originates from the intercondylar fossa of the femur and courses craniolaterally to insert on the craniolateral aspect of the tibial eminence (Fig. 1). The caudal cruciate ligament (CdCL) lies medial to the CrCL, originates from the intercondylar fossa of the femur, and inserts at the popliteal notch of the caudal tibia.3,4 Each femoral condyle is separated from the corresponding tibial plateau by a cartilaginous meniscus that provides cushioning for the joint surfaces (see Fig. 1).5 The lateral meniscus attaches cranially to the tibial eminence and caudally near the attachment of the CdCL with an additional attachment to the intercondylar fossa of the femur via the muscular femoral ligament. The lateral meniscus has no attachment to the lateral collateral ligament. The medial meniscus is attached cranially and caudally to the tibial eminence similarly to the lateral meniscus. In contrast, the medial meniscus is firmly attached to the medial collateral ligament, predisposing the meniscus to concurrent injury in the presence of medial collateral ligament damage.5,6 Each meniscus is further supported by the intermeniscal ligament. The synovial lining is prolific compared with the equine and can become even more extensive and proliferative in inflammatory conditions associated with joint instability and chronic arthritis. CRCL RUPTURE
CrCL rupture is a common cause of lameness referable to the stifle. Traumatic rupture of the CrCL is the primary means of injury in cows, whereas bulls are more likely to develop CrCL rupture secondary to accumulative degenerative joint disease.7,8 It has been suggested that the straightness of the tarsocrural joint in some bulls predisposes to straightness of the stifle, leading to meniscal damage, joint instability, degenerative joint disease, and fraying of the CrCL until rupture.7 Older cattle may also be at higher risk for degenerative changes to the CrCL predisposing to rupture, as is described in dogs.9 Falls are common causes of injury, usually secondary to poor
Fig. 1. The right stifle of a bull with normal intra-articular anatomy (cranial view): A, lateral femoral condyle; B, medial femoral condyle; C, cranial cruciate ligament; D, caudal cruciate ligament; E, cut section of the middle patellar ligament; F, cut section of the medial patellar ligament; G, cut section of the lateral patellar ligament; H, lateral meniscus; I, medial meniscus; L, lateral side; M, medial side.
Stifle Disorders
footing, metabolic disturbances around the time of calving, or associated with mounting injuries attributable to normal estrus behavior. Cattle with higher body condition scores are at higher risk, as are older individuals (mean age, 4–5 years).1,8 Diagnostic Procedures
Physical examination allows diagnosis in most cases. Stifle injury, particularly CrCL rupture, typically results in evidence of nonspecific lameness. A thorough distal limb and hoof evaluation is necessary to rule out lower limb disorders. Lameness in acute cases can be marked, although some individuals may present with milder lameness or have periodic episodes of lameness interspersed with periods of apparently normal gait. The degree of lameness generally decreases substantially with chronic injuries. In some individuals, a clicking sound may be heard when standing, shifting weight, or walking.4 Evaluation of the proximal limb in affected cattle reveals moderate to severe joint effusion. Pain, crepitus, cranial drawer, and increased internal rotation may be found on manipulation of the stifle joint. To elicit cranial drawer, examiners stand behind, place their hands on either side of the limb, and firmly grasp the proximal tibial crest (Fig. 2). By quickly pulling caudally on the tibial crest, the examiner may feel movement and hear a clicking noise in the CrCL-deficient stifle. As an alternative, the examiner can attempt to elicit laxity and crepitus through internal rotation of the tibia by placing one hand on the tibial crest and the other on the point of the hock.
Fig. 2. Cranial drawer in cattle can be elicited to confirm a diagnosis of CrCL rupture. Examiners stand behind the patient and use their knees to brace the hock. The hands are passed along either side of the stifle to grasp the tibial crest firmly. By jerking caudally on the proximal tibia, crepitus associated with a loud clicking noise may be appreciated in the CrCLdeficient stifle.
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Radiographic evaluation of the stifle can support a presumptive diagnosis of cranial cruciate rupture in cases in which physical examination findings are suggestive but inconclusive. In normal cattle, the femoral condyles completely overlap the tibial eminences seen on the lateral view (Fig. 3A). In CrCL-deficient cattle, the lateral radiograph shows the femoral condyles caudal to the tibial intercondylar eminences (see Fig. 3B).7 In acute, traumatic injuries, avulsion of the CrCL can result in osseous fragments within the joint. In chronic cases, evidence of degenerative joint disease (DJD) may be seen radiographically.5,7 Craniocaudal views confirm the presence of DJD, avulsion fragments, and can confirm collateral ligament ruptures caused by joint space incongruity. Arthrocentesis of the bovine joint is best obtained from the area of maximal joint distension. Samples should be acquired from both the femoropatellar and femorotibial joints because the lateral femorotibial joint does not communicate with the other joints in many animals. Analysis of the fluid should indicate sterile inflammation. An 18-gauge needle is sufficient in most cases, although larger needles may be required if the joint fluid is particularly viscous or if proliferative synovium prevents aspiration. Normal joint fluid is transparent with a light yellow color. Normal nucleated cell counts are less than 1000 cells/mL with a total protein of less than 2.5 g/dL. Higher values suggest inflammatory damage or infection. The gold standard for stifle evaluation in the horse is diagnostic arthroscopy. Arthroscopic evaluation has been reported in the bovine but is uncommonly performed because of economic considerations, lack of necessary equipment, and unfamiliarity with arthroscopic landmarks and techniques.10 Arthroscopic evaluation allows definitive diagnosis of cruciate rupture and meniscal damage, but can be difficult in heavy cattle with significant periarticular fat or in chronic cases because of extensive proliferative synovitis (Fig. 4).
Fig. 3. (A) The lateral view of a normal stifle shows the expected superimposition of the femoral condyles over the tibial eminences. (B) The lateral view of a CrCL-deficient stifle shows the cranial movement of the proximal tibia with the femoral condyles caudal to the tibial eminences. A small curvilinear osseous body (arrow) is seen just cranial to the tibial eminence along with increased opacity in the cranial aspect of the joint. These findings are presumed to be degenerative changes and ossification of the CrCL.
Stifle Disorders
Fig. 4. Arthroscopic imaging of the ruptured CrCL reveals fraying of the ligament fibers. Proliferative synovial villi can impede visibility within the joint in cattle with chronic injuries or preexisting DJD. (Courtesy of David Anderson, DVM, MS.)
Treatment
Treatment options vary depending on the perceived economic value of the animal, severity of disease, progression of secondary degenerative joint changes, and availability of the equipment, facilities, and expertise to perform surgical repair. The various options are discussed later. Salvage may be the best option for affected animals if treatment costs cannot be justified. Without treatment, many animals remain painful and develop progressive DJD leading to increased recumbency, decreased feed intake, generalized weight loss, breakdown of soft tissue support structures in the contralateral limb, and disuse atrophy of the gluteal and quadriceps muscle groups.4 Stall rest may be effective for cases of partial CrCL rupture, small cattle (
DVM, MS,
Andrew Niehaus,
DVM, MS*
KEYWORDS Cattle Stifle Lameness Cranial cruciate ligament Meniscus Upward fixation of the patella KEY POINTS Stifle injury is a major source of lameness and can be associated with significant production losses in cattle. Cranial cruciate ligament injury is a common cause of stifle lameness, and treatment options range from conservative management to ligament replacement techniques. Meniscal injury can occur in cattle and is most frequently associated with ligament damage (mainly medial collateral ligament injury). Intermittent upward fixation of the patella is a rare condition affecting cattle in North America but is associated with a good prognosis with accurate diagnosis and surgical intervention.
INTRODUCTION
Stifle injury or disease remains a major source of proximal hind limb lameness in cattle. Structures that are commonly affected include the cranial cruciate ligament (CrCL), the medial meniscus, and the collateral ligaments. Osteoarthritis is a common sequela of a primary traumatic injury or degenerative breakdown of one of these structures. Economic losses associated with stifle disease are related to increased recumbency, decreased feed intake, decreased milk production, loss of muscle mass in the affected limb, conception failure in cows, and reluctance to mount in bulls.1 RELEVANT ANATOMY
The bovine stifle is composed of the femoropatellar, medial femorotibial, and lateral femorotibial joints. Communication exists between the femoropatellar and medial
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon Tharp Street, Columbus, OH 43210, USA * Corresponding author. E-mail address: [email protected] Vet Clin Food Anim 30 (2014) 265–281 http://dx.doi.org/10.1016/j.cvfa.2013.11.008 vetfood.theclinics.com 0749-0720/14/$ – see front matter Ó 2014 Elsevier Inc. All rights reserved.
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femorotibial joints in 100% of stifles and between the medial and lateral femorotibial joints in 65% of stifles.2 Similar to the horse, the bovine patella has a tendinous attachment to the quadriceps apparatus proximally and connects distally to the tibial crest via 3 separate ligaments: the medial, middle, and lateral patellar ligaments. The lateral patellar ligament is continuous with the tendon of the biceps femoris muscle. The cruciate ligaments are intra-articular and extrasynovial and provide rotational and craniocaudal support to the stifle.3 The CrCL originates from the intercondylar fossa of the femur and courses craniolaterally to insert on the craniolateral aspect of the tibial eminence (Fig. 1). The caudal cruciate ligament (CdCL) lies medial to the CrCL, originates from the intercondylar fossa of the femur, and inserts at the popliteal notch of the caudal tibia.3,4 Each femoral condyle is separated from the corresponding tibial plateau by a cartilaginous meniscus that provides cushioning for the joint surfaces (see Fig. 1).5 The lateral meniscus attaches cranially to the tibial eminence and caudally near the attachment of the CdCL with an additional attachment to the intercondylar fossa of the femur via the muscular femoral ligament. The lateral meniscus has no attachment to the lateral collateral ligament. The medial meniscus is attached cranially and caudally to the tibial eminence similarly to the lateral meniscus. In contrast, the medial meniscus is firmly attached to the medial collateral ligament, predisposing the meniscus to concurrent injury in the presence of medial collateral ligament damage.5,6 Each meniscus is further supported by the intermeniscal ligament. The synovial lining is prolific compared with the equine and can become even more extensive and proliferative in inflammatory conditions associated with joint instability and chronic arthritis. CRCL RUPTURE
CrCL rupture is a common cause of lameness referable to the stifle. Traumatic rupture of the CrCL is the primary means of injury in cows, whereas bulls are more likely to develop CrCL rupture secondary to accumulative degenerative joint disease.7,8 It has been suggested that the straightness of the tarsocrural joint in some bulls predisposes to straightness of the stifle, leading to meniscal damage, joint instability, degenerative joint disease, and fraying of the CrCL until rupture.7 Older cattle may also be at higher risk for degenerative changes to the CrCL predisposing to rupture, as is described in dogs.9 Falls are common causes of injury, usually secondary to poor
Fig. 1. The right stifle of a bull with normal intra-articular anatomy (cranial view): A, lateral femoral condyle; B, medial femoral condyle; C, cranial cruciate ligament; D, caudal cruciate ligament; E, cut section of the middle patellar ligament; F, cut section of the medial patellar ligament; G, cut section of the lateral patellar ligament; H, lateral meniscus; I, medial meniscus; L, lateral side; M, medial side.
Stifle Disorders
footing, metabolic disturbances around the time of calving, or associated with mounting injuries attributable to normal estrus behavior. Cattle with higher body condition scores are at higher risk, as are older individuals (mean age, 4–5 years).1,8 Diagnostic Procedures
Physical examination allows diagnosis in most cases. Stifle injury, particularly CrCL rupture, typically results in evidence of nonspecific lameness. A thorough distal limb and hoof evaluation is necessary to rule out lower limb disorders. Lameness in acute cases can be marked, although some individuals may present with milder lameness or have periodic episodes of lameness interspersed with periods of apparently normal gait. The degree of lameness generally decreases substantially with chronic injuries. In some individuals, a clicking sound may be heard when standing, shifting weight, or walking.4 Evaluation of the proximal limb in affected cattle reveals moderate to severe joint effusion. Pain, crepitus, cranial drawer, and increased internal rotation may be found on manipulation of the stifle joint. To elicit cranial drawer, examiners stand behind, place their hands on either side of the limb, and firmly grasp the proximal tibial crest (Fig. 2). By quickly pulling caudally on the tibial crest, the examiner may feel movement and hear a clicking noise in the CrCL-deficient stifle. As an alternative, the examiner can attempt to elicit laxity and crepitus through internal rotation of the tibia by placing one hand on the tibial crest and the other on the point of the hock.
Fig. 2. Cranial drawer in cattle can be elicited to confirm a diagnosis of CrCL rupture. Examiners stand behind the patient and use their knees to brace the hock. The hands are passed along either side of the stifle to grasp the tibial crest firmly. By jerking caudally on the proximal tibia, crepitus associated with a loud clicking noise may be appreciated in the CrCLdeficient stifle.
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Radiographic evaluation of the stifle can support a presumptive diagnosis of cranial cruciate rupture in cases in which physical examination findings are suggestive but inconclusive. In normal cattle, the femoral condyles completely overlap the tibial eminences seen on the lateral view (Fig. 3A). In CrCL-deficient cattle, the lateral radiograph shows the femoral condyles caudal to the tibial intercondylar eminences (see Fig. 3B).7 In acute, traumatic injuries, avulsion of the CrCL can result in osseous fragments within the joint. In chronic cases, evidence of degenerative joint disease (DJD) may be seen radiographically.5,7 Craniocaudal views confirm the presence of DJD, avulsion fragments, and can confirm collateral ligament ruptures caused by joint space incongruity. Arthrocentesis of the bovine joint is best obtained from the area of maximal joint distension. Samples should be acquired from both the femoropatellar and femorotibial joints because the lateral femorotibial joint does not communicate with the other joints in many animals. Analysis of the fluid should indicate sterile inflammation. An 18-gauge needle is sufficient in most cases, although larger needles may be required if the joint fluid is particularly viscous or if proliferative synovium prevents aspiration. Normal joint fluid is transparent with a light yellow color. Normal nucleated cell counts are less than 1000 cells/mL with a total protein of less than 2.5 g/dL. Higher values suggest inflammatory damage or infection. The gold standard for stifle evaluation in the horse is diagnostic arthroscopy. Arthroscopic evaluation has been reported in the bovine but is uncommonly performed because of economic considerations, lack of necessary equipment, and unfamiliarity with arthroscopic landmarks and techniques.10 Arthroscopic evaluation allows definitive diagnosis of cruciate rupture and meniscal damage, but can be difficult in heavy cattle with significant periarticular fat or in chronic cases because of extensive proliferative synovitis (Fig. 4).
Fig. 3. (A) The lateral view of a normal stifle shows the expected superimposition of the femoral condyles over the tibial eminences. (B) The lateral view of a CrCL-deficient stifle shows the cranial movement of the proximal tibia with the femoral condyles caudal to the tibial eminences. A small curvilinear osseous body (arrow) is seen just cranial to the tibial eminence along with increased opacity in the cranial aspect of the joint. These findings are presumed to be degenerative changes and ossification of the CrCL.
Stifle Disorders
Fig. 4. Arthroscopic imaging of the ruptured CrCL reveals fraying of the ligament fibers. Proliferative synovial villi can impede visibility within the joint in cattle with chronic injuries or preexisting DJD. (Courtesy of David Anderson, DVM, MS.)
Treatment
Treatment options vary depending on the perceived economic value of the animal, severity of disease, progression of secondary degenerative joint changes, and availability of the equipment, facilities, and expertise to perform surgical repair. The various options are discussed later. Salvage may be the best option for affected animals if treatment costs cannot be justified. Without treatment, many animals remain painful and develop progressive DJD leading to increased recumbency, decreased feed intake, generalized weight loss, breakdown of soft tissue support structures in the contralateral limb, and disuse atrophy of the gluteal and quadriceps muscle groups.4 Stall rest may be effective for cases of partial CrCL rupture, small cattle (
