operated cruciate worse than knees treated non-surgically

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Evidence based take home message for your pet from article below

Numerous studies with follow-up periods of 5 years or longer do not support the theory that surgical treatment is the best treatment for restoring knee function. In fact, in 1994 a study examining scintigraphic and radiographic changes in knees managed surgically versus non-surgically found that 5 years after the injury the reconstructed knees showed markedly greater degeneration than those treated non-surgically.
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CRUCIATE DISEASE – WHAT CAN WE LEARN FROM THE HUMAN LITERATURE

Christopher M. Hill, VMD, Diplomate ACVS
ACVS Symposium Equine and Small Animal Proceedings
October 1, 2001


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CRUCIATE DISEASE – WHAT CAN WE LEARN FROM THE HUMAN LITERATURE

Christopher M. Hill, VMD, Diplomate ACVS, Mobile Veterinary Surgical Associates, Charleston, South Carolina

2001 ACVS Veterinary Symposium Small Animal Proceedings


Keywords: Cruciate disease, non-operative, surgery, graft, dog, cat, small animal



The anterior cruciate ligament (analogous to the cranial cruciate ligament in canines) plays several roles in the maintenance of stability and function of the knee. It prevents cranial translation of the tibia, resists excessive internal rotation of the tibia, and prevents hyperextension of the knee. It also acts as a secondary restraint against varus or valgus angulation.



Cruciate rupture, resulting in abnormal anterior-posterior movement of the tibia, was first described in humans in the mid-1800’s. Treatment at that time consisted of immobilization with a removable splint and application of cold water to reduce inflammation. In the early 1900’s operative treatment began to gain popularity with various extra-articular and intra-articular techniques being tried out in humans and, experimentally, in dogs. Most of these procedures utilized fascia lata grafts, patellar tendon grafts, or silk suture to appose the torn ligament. Beginning in the 1940’s the tendon of insertion of the semitendinosus and gracilis muscles were also used as intra-articular grafts. In 1976 Feagin and Curl published follow-up of West Point cadets who had cruciate repair during their college years. The availability of complete military medical records provided an unprecedented accurate follow-up of the surgical procedures. The disappointing news was that a large percentage of the repairs were unsuccessful. Since then surgeons have been refining the various techniques by identifying the most isometric placement of the grafts, using tissues of high strength and stiffness and minimizing operative morbidity via the use of arthroscopes and early rehabilitation.



The goals of surgical reconstruction are to stabilize the knee, return the patient to pre-injury activity level, and prevent the progression of osteoarthritis. So far no procedure has reliably produced these results, consequently there is much controversy regarding the best way to reconstruct the cruciate deficient knee. Clinical studies in humans have shown that simple suturing of the acutely torn ligament produces a similar outcome as non-operative treatment

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Grafts can be autogenous tissue, synthetic prostheses, or allografts. Each has its advantages and disadvantages, and none are an ideal substitute for the cruciate ligament. Placement of the graft can be either extra-articular, intra-articular, or a combination of the two.



The concept of muscle transfers to “dynamically stabilize” the knee has never been validated scientifically and it is thought that the speed with which injury occurs is much faster than any reflex arc that may attempt to protect the knee via muscle contraction.
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Extra-articular Repairs

Most extra-articular repairs create a restraining band on the lateral side of the knee extending from the lateral femoral condyle to Gerdy tubercle on the tibia, in a line parallel to the cranial cruciate ligament. This type of repair was commonplace in humans during the 1970’s and 1980’s. Kinematic studies to determine the optimal attachment points in humans found the best femoral attachment to be just proximal to the lateral collateral ligament and the best tibial attachment to be on the anteriolateral aspect, just at or in front of the Gerdy tubercle. These studies also showed that the stress exerted on the reconstruction depended mostly on the location of the femoral attachment and much less so on the tibial attachment. Extra-articular repairs have the advantage of providing good blood supply to the grafted tissue, thus minimizing the chance of necrosis and failure. Outcome of one series of extra-articular repairs performed in humans in 1985 showed 35% excellent, 43% good, 13% fair and 9% poor. The good/excellent group had a mean follow-up period of 4.4 years and the fair/poor group had a mean follow-up period of 6.7 years, which suggests there may be stretching and deterioration of the repair with time.
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Intra-articular Repairs Using an Autograft

Intra-articular repairs are the current “gold standard” for reconstruction of the human knee. Although both allografts and autografts are commonly used, autografts seem to have gained wider acceptance. Two of the most commonly used autografts are bone-patellar tendon-bone and semitendinosus-gracilis tendon constructs. A major advantage of using the patellar tendon is that it provides the immediate stability of bone to bone fixation which allows rapid rehabilitation and immediate full weight-bearing. Disadvantages of the patellar tendon graft are weakening of the quadriceps muscle, patellofemoral pain, and occasionally, rupture of the remaining patellar tendon. Studies in dogs, goats and rabbits have shown harvesting the central third of the patellar tendon will significantly decrease the strength and stiffness of the remaining tendon even in the long term. The semitendinosus-gracilis graft is technically easier to harvest and is associated with less operative dissection and post-operative morbidity. Follow-up studies of hamstring strength have shown no significant decrease at 2 years after surgery. Initially there were concerns that the time required for the tendon to heal to bone might prolong the post-operative rehabilitation period. This has since been proven untrue. Studies directly comparing the two techniques have shown no difference in either functional outcome or laxity on instrumented testing even when immediate full weight-bearing and full range of motion exercises were performed. There are numerous minor variations of these two intra-articular grafting techniques, however almost all studies in human patients report 85-90% excellent/good results and 10-15% fair/poor results.



All autogenous grafts undergo the process of necrosis, revascularization, and maturation. Experimental studies have shown patellar tendon grafts become enveloped by a highly vascular synovial-like tissue during the first 4-6 weeks, while the core undergoes ischemic necrosis. By 20 weeks revascularization and repopulation of the entire graft with new cells takes place, although the process of remodeling goes on longer. Concomitant with the revascularization, numerous morphologic, biochemical, and biomechanical changes take place involving changes in cell morphology, collagen cross-linking patterns and glycosaminoglycan content. The bone-patellar tendon-bone and semitendinosus-gracilis tendon grafts have an initial strength superior to that of a normal ACL in humans, however they both undergo an initial significant decrease in strength followed by a gradual increase as remodeling takes place. The mature graft never attains 100% of its initial strength. Experimental studies in monkies and goats have shown that one year after reconstruction the strength and stiffness of the graft is only 30% to 50% of the normal cruciate ligament.



Intra-articular Repairs Using an Allograft

Bone-patellar tendon-bone, Achilles tendon, and fascia lata are the most commonly used allografts in humans. The major advantages are no donor site morbidity for the recipient, various sizes to choose from, and since there is no need to do any type of antigenic matching between donor and recipient, an ample supply is available. A potential disadvantage is the time required for graft incorporation. Canine studies have shown allografts become incorporated in a manner similar to that of an autograft, however it occurs at a slower rate. During this time the graft is vulnerable to failure if too much stress is placed on it, consequently rehabilitation takes longer. Potential for disease transmission is a major disadvantage of using allografts.



There are three different methods to process and preserve bone and soft-tissue allografts: deep freezing (-70° C), freeze drying, and cryopreservation. Deep freezing is an excellent preservation technique that decreases antigenicity of the graft and maintains structural integrity. This is the preferred method for cruciate ligament grafts. The majority of allograft tissue is collected under aseptic conditions and undergoes repeated bacterial and fungal culturing episodes in order to ensure sterility. Because of the risk of viral transmission some sort of secondary sterilization procedure is usually performed. Ethylene oxide and gamma radiation are two of the most commonly used methods. Ethylene oxide has been associated with reactive synovial and bony changes after graft implantation and has been shown to be ineffective in eradicating feline leukemia virus from feline bone. For these reasons it is not recommended for virus sterilization of biologic tissues. The American Association of Tissue Banks recommended irradiation dosage is between 1.5 and 2.5 Mrads, although some spore forming organisms and certain viruses, such as HIV, are not inactivated by this dose. Some studies have suggested that approximately 3.6 Mrad is needed to inactivate HIV in bone, however, there is a significant, and dose-dependent deterioration of the mechanical properties of tissues sterilized above 2.0 Mrads. Studies using goat patellar ligament showed that 3.0 Mrads of irradiation decreased force to maximum failure by 27%. Gamma irradiation also affects the strength of the graft after incorporation in the host body. In a goat model it was found that 4 Mrads decreased graft stiffness by 33% to 40% at 6 months post-op. Compared to control knees, 2.0 Mrads did not significantly decrease any mechanical properties measured 6 months post-operatively.



There are no studies directly comparing success rates of allograft reconstructions with autograft reconstructions, although they are thought to be similar. A review of the literature shows a good or excellent outcome in 60-90% of human patients receiving bone-patellar tendon-bone allografts.



Non-operative Treatment

There is still considerable debate as to whether operative treatment provides superior results to non-operative treatment for anterior cruciate injuries in people. Numerous studies with follow-up periods of 5 years or longer do not support the theory that surgical treatment is the best treatment for restoring knee function. In fact, in 1994 a study examining scintigraphic and radiographic changes in knees managed surgically versus non-surgically found that 5 years after the injury the reconstructed knees showed markedly greater degeneration than those treated non-surgically. Other follow-up studies, in 1996 and 1997, have revealed that 10 years post-operatively reconstructed knees continue to show greater degenerative changes on radiographs than those treated non-surgically. An ongoing study following patients with unstable knees in particular, has confirmed that knees may remain free of degenerative changes despite chronic, abnormal laxity. This study also showed no difference in activity level between patients receiving surgical stabilization and those left unstable.

Non-operative treatment does not imply no treatment. Successful rehabilitation focuses on strengthening the muscles, improving balance and coordination, and restricting loads put on the knee. Functional bracing and anti-inflammatory therapy are also used in non-operative management of cruciate injuries. Approximately 80-90% of patients treated in this manner will have a satisfactory outcome.
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[Guest]

nothing because dogs dont walk upright on 2 legs

[whistle blower]

Citation 4.
Link to... • • • Accession Number
00004624-200111000-00003.

Author
Beard, D. J.; Murray, D. W.; Gill, H. S.; Price, A. J.; Rees, J. L.; Alfaro-Adrian, J.; Dodd, C. A. F.

Institution
From the Nuffield Orthopaedic Centre, Oxford, England
D. J. Beard, DPhil, Senior Fellow; D. W. Murray, FRCS, Professor of Orthopaedics; A. J. Price, FRCS, Research Fellow; J. L., Rees, FRCS, Research Fellow; C. A. F. Dodd, FRCS, Consultant Orthopaedic Surgeon; H. S. Gill, DPhil, Senior Fellow; Nuffield Orthopaedic Centre NHS Trust, Windmill Road, Headington, Oxford OX3 7LD, UK.
J. Alfaro-Adrian, FRCS, Orthopaedic Surgeon; Clinica La Zarzuela, Departmento de Traumatologia, 28023 Aravaca, Madrid, Spain.

Title
Reconstruction does not reduce tibial translation in the cruciate-deficient knee: AN IN VIVO STUDY.[Miscellaneous Article]

Source
Journal of Bone & Joint Surgery - British Volume. 83-B(8):1098-1103, November 2001.

Local Message
MEDICAL LIBRARY OWNS

Abstract
We have assessed the effectiveness of reconstruction of the anterior cruciate ligament (ACL) in reducing functional tibial translation (TT).

The gait of 11 ACL-deficient patients was studied using Vicon equipment before and after surgery. Measurements of the angle between the patellar tendon and the long axis of the tibia were obtained in order to calculate TT in the sagittal plane relative to the uninjured limb during standing and walking.

Before surgery, patients did not show abnormal TT on the injured side, but after surgery significant anterior TT was found in the operated limb for every parameter of gait.

Abnormal anterior TT occurring during activity does not seem to be reduced by reconstruction; rather, it increases. It may be that the increased translation results from relaxation of excess contraction of the hamstring muscles, since compensatory muscle activity no longer is required in a reconstructed knee. The reduction of TT may not be an appropriate objective in surgery on the ACL.

(C) 2001 British Editorial Society of Bone and Joint Surgery

[malernee]

APPLICATIONS OF EVIDENCE-BASED MEDICINE: CRANIAL CRUCIATE LIGAMENT INJURY

Steven C. Budsberg, DVM, MS, Diplomate ACVS, University of Georgia, Athens, Georgia

Small Animal Proceedings

Evidence Based Medicine Track

Keywords: evidence, canine, studies, ligament, guidelines

From earlier papers, one can see that evidence-based medicine attempts to take the results of population studies and apply them to an individual animal. This is in stark contrast to traditional medical practice in which clinical experience (often from individual patients) is commonly used to define and defend the treatment of an entire group of patients with a similar problem. Nowhere can this paradox be seen more commonly than in surgical practice. Certainly, within veterinary orthopedics, clinical experience is still the driving force behind the vast majority of decisions made on the use of specific surgical procedures. This holds true for procedures recommended for cruciate injuries.

The process of constructing clinical practice guidelines from evidence-based medicine is to first define the question you would like to answer. Certainly, in this case while formulating a single question regarding cruciate injuries would appear easy, further examination reveals several significant questions that do need to be addressed. The first question to be asked for the sake of this discussion will be:

In dogs with cranial cruciate injuries and instability (<I style="mso-bidi-font-style: normal">patient or problem), which surgical procedure (<I style="mso-bidi-font-style: normal">intervention considered) will allow consistent return to normal clinical function postoperatively (<I style="mso-bidi-font-style: normal">intervention outcome) and is that procedure superior to other current techniques (<I style="mso-bidi-font-style: normal">comparison population)?

This question is probably too broad to answer fully at the present time, but we will use it as an example as it is the question that everyone really wants to know the answer to in veterinary orthopedic practice today. Other questions that need to be answered include: what is the best treatment recommendation for suspected or proven partial cruciate tears without instability? What is the best postoperative physical therapy regimen for dogs undergoing cruciate stabilization? Etc.

Next, we must find the evidence to attempt to answer the question. Searches were done through VIN, MEDLINE and CAB ABSTRACTS. While greater than 200 journal articles, proceedings and abstracts were evaluated, less than 20 provided relevant data for answering the aforementioned question.



Analysis of the Evidence

Limited evidence was available to help develop an answer to the question posed or providing data to construct any clinical practice guidelines. As stated previously when high-quality evidence is still not available for a given clinical question, explicit criteria for judging the quality of a study is mandatory. Each of these classes was used to catalog and evaluate the current available data.

<I style="mso-bidi-font-style: normal">Class I – Evidence derived from multiple, randomized, blinded, placebo-controlled trials: None available.

<I style="mso-bidi-font-style: normal">Class II – Evidence derived from high quality clinical trials using historical controls: Limited to none depending on the strictness of the criteria you apply. To my definition, no studies made it into this category.

<I style="mso-bidi-font-style: normal">Class III – Evidence derived from uncontrolled case series: This category is the majority of “peer reviewed data” available to the clinician today who attempts to understand the reasons for current recommendations stated for cruciate injuries. These studies varied from a study that a prospective comparison, but is not truly randomized, with limited subjective outcome measurements to uncontrolled case series with outcome measurements that ran the gambit from objective gait analysis to clinical impressions.

<I style="mso-bidi-font-style: normal">Class IV – Evidence derived from expert opinion, and/or extrapolated from bench research or physiologic studies: This category is unfortunately the most prominent source of information available today in regard to cruciate injuries and repair. In this review I have listed some of the more complete retrospective studies done to date, but none should be construed as providing extremely useful information to this discussion. Unfortunately, clinical practice has and will continue to be guided by these data in the absence of more reliable evidence. This review underscores the need for funding sources to support large, time consuming and expensive clinical trials.

In summarizing the evidence available, it is clear than no single procedure has enough data that allows any statements about potential for long term success in terms of clinical outcome. Furthermore, given the data available today, it is impossible to favor one procedure (TPLO, fibular head transposition, extracapsular suture stabilization, intracapsular ligament replacement) over another at this time.



Beckman SL, Wadsworth PL, Hunt CA, et al.: Technique for stabilizing the stifle with nylon bands in cases of ruptured anterior cruciate ligaments in dogs. J Am Anim Hosp Assoc 28:539-544, 1992

Budsberg SC, Verstraete MC, Soutas-Little RWm, et al.: Force plate evaluation before and after stabilization of the stifle for cruciate injury. Am J Vet Res 49:1522-1524, 1988

Chauvet AE, Johnson AL, Pijanowski GJ, et al.: Evaluation of fibular head transposition, lateral fabellar suture, and conservative treatment of cranial cruciate ligament rupture in large dogs: a retrospective study. J Am Anim Hosp Assoc 32: 62-463, 1996

Conzemius MG, Gordon WJ, Besancon MF, et al.: The effect of surgical technique on limb function after surgery for cranial cruciate ligament disease in the labrador retriever. Vet Surg 31:479, 2002

Denny HR, Barr Ars: An evaluation of two ‘Over the Top’ techniques for anterior cruciate replacement in the dog. J Small Anim Prac 25:759-769, 1984

Denny HR, Goodship AE: Replacement of the anterior cruciate ligament with carbon fibre in the dog. J Small Anim Pract 21:279-286, 1980

Elkins AD, Pechman R, Kearney MT, et al: A retrospective study evaluating the degree of degenerative joint disease in the stifle joint of dogs following surgical repair of anterior cruciate ligament rupture. J Am Anim Hosp Assoc 27:533-540, 1991

Goetzee GL, Lubbe AM: A prospective study comparing two fascial reconstruction techniques to stabilize the cranial cruciate deficient stifle in the dog. Vet Comp Orth Trauma 8:82-90, 1995

Innes JF, Bacon D, Lynch C, et al: Long-term outcome of surgery for dogs with cranial cruciate ligament deficiency. Vet Rec 147:325-328, 2000

Innes JF, Barr ARS. Clinical natural history of the post surgical cruciate deficient canine stifle joint: Year 1. J. Small Anim Prac 39:325-332, 1998

Laitinen O.: Prospective clinical study of biodegradable poly-l-lactide implant as an augmentation device with fascia lata in cranial cruciate ligament repair in the dog: early results. Vet Comp Ortho Trauma 7:1-55, 1994

Lazar TP, Berry CR, deHaan JJ, et al.: Long-term comparison of stifle osteoarthritis in dogs with surgical repair of cranial cruciate ligament injury utilizing tibial plateau leveling osteotomy versus extracapsular stabilization. Vet Surg 30:498, 2001

Moore KW, Read RA: Cranial cruciate ligament rupture in the dog - a retrospective study comparing surgical techniques. Aus Vet J 72:281-285, 1995

Shires PK, Hulse DA, Liu W: The under-and-over fascial replacement technique for anterior cruciate ligament rupture in dogs: A retrospective study. J Am Anim Hosp Assoc 20:69-77, 1984

Slocum B, Slocum TD: Tibial plateau leveling osteotomy for repair of cranial cruciate ligament rupture in the canine. Vet Clin North Am [Sm An Prac] 23:777-795, 1993

Smith GK, Torq JS: Fibular head transposition for repair of cruciate-deficient stifles in the dog. J Am Vet Med Assoc 187:375-384, 1985

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ETIOLOGY OF CRUCIATE DISEASE: WHAT’S NEW?

John F. Innes, BVSc, PhD, DSAS(orth) MRCVS, University of Liverpool, Liverpool, United Kingdom

Small Animal Proceedings

Arthrology Track

Keywords: canine feline, cruciate, joint, ligament, stifle

Disease of the cranial cruciate ligament (CCL) is the most common condition to affect the canine stifle joint. Despite this, it is still a poorly understood disease. The postulated factors involved in the pathogenesis of CCL rupture are many. These include: breed, age, gender, neutering, ischemia, obesity, immune mechanisms, tibial plateau angle, intercondylar notch and local biomechanics. Some of these factors have been investigated, and some are currently under investigation.



Risk Factors for CCL Disease – Age, Breed, Gender

CCL rupture occurs in all sizes of dogs but affects larger breed dogs more than smaller dogs, and at a younger age. Obesity is also likely to be a risk factor1,2 although further work is required in this area. Epidemiological studies have indicated an increased incidence of CCL disease in breeds such as the Newfoundland, Rottweiler and Labrador retriever, with infrequent occurrence in the Greyhound, Bassett Hound and Old English sheepdog.

CCL rupture occurs more commonly in neutered animals, particularly females. It is unknown if this is secondary to abnormal weight gain as certain authors have reported that 45.4% of spayed bitches are obese.



Metabolism of the CCL

With the increased risk of CCL disease in certain breeds and neutered animals, one can ask many questions relating to the nature of the tissue in these animals. Is the CCL “normal” in these animals? For example, is the structure and turnover of the CCL normal? Is the biochemistry of CCL normal? Does hormonal status influence CCL metabolism and function?

Over the last few years, we have undertaken studies to examine CCL biochemistry, ultrastructure and biomechanics of CCLs from two at-risk breeds (Labrador and Golden retriever) and compared these to a low-risk breed (Greyhound).3 In all of our studies, the CCLs were harvested from dogs euthanatized for reasons unrelated to stifle disease and all dogs had grossly normal stifle joints and CCLs.

We have examined the ultrastructure of the CCLs in these breeds using transmission electron microscopy. We have assessed collagen fibril diameter and found that the mean fibril diameter in the Labrador is significantly smaller than that of the Greyhound. This is interesting in that recent experimental work has demonstrated that following CCL transection, the collagen fibril diameter of the caudal cruciate ligament decreases.4 This suggests that fibril diameter is a marker for altered loading.

We have also examined markers of collagen turnover in CCLs from these breeds of dog. We have used gelatin gel zymography to demonstrate that tissue concentrations of gelatinase (matrix metalloproteinase [MMP]- 2) are upregulated in the at-risk breeds compared to controls. Furthermore, using reverse zymography we have demonstrated that concentrations of tissue inhibitor of MMPs (TIMP-2) are lower in the at-risk breeds compared to control. In addition, we have studied cross-linking profiles of collagen within these tissues using HPLC. Breeds at risk for CCL disease show more intermediate collagen cross-links compared to controls. Taken together, these data suggest that collagen turnover in CCLs from at-risk breeds is increased. This could be constituitive, or induced.

Connective tissue metabolism has been shown to be influenced by the endocrine system (Takeda, Suzuki et al. 1975). Female human athletes are more prone to anterior cruciate ligament rupture compared to male athletes. In rabbits, estrogen has been shown to downregulate metabolism of CCL cells in vitro. Furthermore, estrogen has been reported to decrease collagen synthesis in the human anterior cruciate ligament and an increased incidence of rupture has been recognized at certain stages in the female menstrual cycle. Estrogen receptors have been demonstrated on the surface of ACL cells. Neutering in dogs has been shown to increase the risk of CCL disease and this may relate to change in hormonal status. However, it is also possible that this increased risk relates to increased bodyweight caused by obesity induced by neutering. Conversely, one should also consider the hormonal output of white adipose tissue and the possibility that these hormones (e.g. leptin) may affect connective tissue metabolism.



CCL Disease – Biomechanical Perspectives

Tibial plateau angle: In recent years, the tibial plateau has been a subject of much debate. Does an excessive slope to the tibial plateau contribute to the incidence of CCL disease? One study suggests that dogs with CCL rupture do have an excessive slope to the tibial plateau.5 In this study, the authors measured the tibial plateau angle (TPA) in three groups of dogs. Stifle joints were measured from lateral radiographic views to determine TPA in these groups: Group 1 dogs had CCL injuries; Group 1A dogs, a subgroup of Group 1, had one unaffected stifle joint and Group 2 dogs had no CCL injuries. Age, sex, breed, body weight, limb injured and TPA were recorded for each dog. In 56 stifle joints measured in Group 1, the mean TPA was 23.8o. Sixty stifle joints were measured in Group 2 dogs and the mean TPA was 18.10 degrees. The most common breeds included Labrador retriever, Golden retriever and Rottweiler. The TPAs of dogs in Group 1 were significantly greater than the TPAs of dogs in Group 2. However, other studies have failed to substantiate these data. Wilke and colleagues measured traditional and standing TPAs in affected and unaffected Labradors and unaffected Greyhounds.6 Standing position, horizontal-beam radiography was performed on Greyhounds and unaffected Labrador retrievers to determine standing TPA. Lateral radiography of the stifle joint was performed on all dogs to determine traditional TPA. Greyhounds had mean standing TPA of 1.56o and mean traditional TPA of 22.50o. Unaffected Labrador retrievers had mean standing TPA of 3.52o and traditional TPA of 27.97o. Affected Labrador retrievers had mean traditional TPA of 25.55o. No significant difference was found in mean standing TPA between Greyhounds and unaffected Labrador retrievers. In addition, standing TPAs in Greyhounds and unaffected Labrador retrievers were not significantly different from a plane drawn parallel to the ground. Significant differences in traditional TPAs were detected among all three groups. Although affected Labrador retrievers had mean traditional TPA that was significantly greater than that of Greyhounds, the steepest TPA was found in unaffected Labrador retrievers. The authors concluded that although TPA may be associated with damage to the cruciate ligaments, many dogs with a steep TPA do not develop cruciate ligament disease.



Figure 0: Cranial-caudal forces within the stifle joint for the normal Greyhound and normal Labrador retriever



Stifle biomechanics: We have recently undertaken studies to investigate the in vivo biomechanics of the normal Greyhound and normal Labrador (Colborne and others, unpublished data). We have used a combination of kinetic (Kistler force platform), kinematic (Qualysys kinematic system) and morphometric measures to estimate the moments, work and power acting through the canine stifle joint. Our preliminary findings indicate consistent differences between these two breeds of dog. Interestingly, the Labrador has a peak cranial caudal force of 1N/Kg acting through the stifle joint at the trot but a similar estimate for the Greyhound is only 0.5


N/Kg (Figure 1). This is the force that the CCL must resist.

We have also detected differences in power particularly in the latter part of stance phase, suggesting differences in muscle action between these two breeds. Our future studies will investigate the alterations in these parameters in dogs with CCL rupture and also the effect on these parameters of various surgical techniques.



Whitehair JG, Vasseur PB, Willits NH: Epidemiology of cranial cruciate ligament rupture in dogs. J Am Vet Med Assoc 203:1016-1019, 1993

Doverspike M, Vasseur PB, Harb MF, Walls CM: Contralateral cranial cruciate ligament rupture: Incidence in 114 dogs. J Am Anim Hosp Assoc 29:167-170, 1993

Comerford E: Comparison of biochemical and biomechanical properties of cranial cruciate ligaments in the Greyhound, Labrador Retriever and Golden Retriever. PhD thesis, Department of Clinical Veterinary Science, University of Bristol, 2003

Zachos TA, Arnoczky SP, Lavagnino M, Tashman S: The effect of cranial cruciate ligament insufficiency on caudal cruciate ligament morphology: An experimental study in dogs. Vet Surg 31:596-603, 2002

Morris E, Lipowitz AJ: Comparison of tibial plateau angles in dogs with and without cranial cruciate ligament injuries. J Am Vet Med Assoc 218:363-366, 2001

Wilke VL, Conzemius MG, Besancon ME, Evans RB et al: Comparison of tibial plateau angle between clinically normal Greyhounds and Labrador Retrievers with and without rupture of the cranial cruciate ligament. J Am Vet Med Assoc 221:1426-1429, 2002

[guest]

found this website a interesting read

http://home.earthlink.net/~tiggerpoz/id5.html

[guest]

Sarcoma of the Proximal Portion of the Tibia in a Dog 5.5 Years After Tibial Plateau Leveling Osteotomy
J Am Vet Med Assoc 227[10]:1613-1617 Nov 15'05 Case Report 20 Refs

* Randy J. Boudrieau, DVM, DACVS; Robert J. McCarthy, DVM, MS, DACVS; Richard D. Sisson, Jr, PhD
* Dept of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA 01536
Osseous neoplasia was identified in the proximal portion of the tibia and distal portion of the femur in an 11.75-year-old spayed female German Shepherd Dog. A tibial plateau leveling osteotomy, followed by application of a metal plate, had been performed on the affected limb 5.5 years earlier. Areas of osteolysis and periosteal proliferation were seen radiographically, with an intense area of osteolysis directly beneath the metal plate. Histologically, the tumor was identified as a poorly differentiated sarcoma. Extracellular and intracellular debris was seen histologically, and energy-dispersive x-ray analysis confirmed that this debris was metallic. On visual examination, areas of the underside of the metal plate that had been in contact with bone had a dull, roughened appearance, and scanning electron microscopy of these areas revealed multiple corrosion pits. The plate was strongly magnetic, suggesting that it contained ferrite, and metallographic examination of the plate revealed substantial differences in the chemical makeup of various parts of the plate. Microstructure analysis revealed that the plate consisted of an austenite matrix with a large fraction of ferrite.
The plate was determined to be a cast 316L stainless steel implant, but it did not meet American Society for Testing Materials standards for implant-grade materials. The possibility that implant corrosion might have played a role in tumor development is of concern; however, a definitive association was not established. [Summary]

[malernee]

Arthroscopic evaluation of the articular cartilage after anterior cruciate ligament reconstruction: a short-term prospective study of 105 patients.

Asano H, Muneta T, Ikeda H, Yagishita K, Kurihara Y, Sekiya I.

Department of Orthopedics, Tokyo Medical and Dental University, Tokyo, Japan. h-asano@mtg.biglobe.ne.jp

PURPOSE: Several reports have shown the progression of degenerative osteoarthritis after anterior cruciate ligament (ACL) reconstruction. No report has been published about early cartilage change after ACL reconstruction. The purpose of this study was to evaluate the articular cartilage after ACL reconstruction in a short postoperative period by arthroscopy. TYPE OF STUDY: Case series. METHODS: We examined the status of articular cartilage of 105 patients who received ACL reconstruction and second-look arthroscopy. Cartilage lesion was evaluated arthroscopically in the 6 articular surfaces independently, and these features were classified by modified Outerbridge's classification. We compared the articular cartilage at reconstruction and at second-look arthroscopy. RESULTS: A significant worsening of the status of the articular cartilage was seen after ACL reconstruction. This worsening was seen at all articular surfaces except the lateral femoral condyle. Most of the change involved softening or fibrillation. Anterior laxity and meniscal lesion had no correlation with a progression of degenerative change of articular cartilage. Patient's age influenced the progression of articular cartilage damage after reconstruction significantly in our cases. CONCLUSIONS: The status of articular cartilage was significantly worsened after ACL reconstruction. Potent risk factors causing articular cartilage damage include female gender and age of 30 years or older. LEVEL OF EVIDENCE: Level IV.

PMID: 15122137 [PubMed - indexed for MEDLINE]

[malernee]

Australian veterinary journal
Volume 87 | Issue 11 (November 2009)

Tibial wedge ostectomy: complications of 300 surgical procedures.

Aust Vet J. November 2009;87(11):438-44.
S Kuan1, B Smith, A Black
1 University Veterinary Teaching Hospital Sydney, University of Sydney, New South Wales, Australia. sooyuin@yahoo.com.au
Abstract

BACKGROUND: Tibial wedge ostectomy (TWO) is a surgical procedure that aims to give functional stability during weight-bearing in a hindlimb with cranial cruciate ligament deficiency, by reducing the slope of the tibial plateau angle. PROCEDURE: Advantages of the TWO surgery are that it does not require dedicated equipment and can be performed in young dogs prior to closure of the physis. However, it is a technically demanding procedure and the potential for complications is high. RESULTS: In this retrospective review of 249 dogs that had unilateral and 51 that had bilateral TWO surgery, the overall complication rate was 31.7% (95/300) and the rate of revision surgery was considerable (37 cases or 12.33%). CONCLUSIONS: The most important clinical complications were postoperative medial meniscal tears, tibial fractures and implant failures, necessitating repeat surgery.