Diagnostic and Surgical Arthroscopy in the Horse

C. Wayne McIlwraith, Ian Wright, Alan J. Nixon

• Publisher: Mosby Ltd.
• Year: 2014
• ISBN:
  9780723438175
• Edition: 4
• Topic: Medicine
• Subtopic: Equine Veterinary Science

From the worldwide leader in equine surgery, Wayne McIlwraith, comes the new fourth edition of Diagnostic and Surgical Arthroscopy in the Horse. Completely revised and expanded, this comprehensive atlas covers all the need-to-know information within equine arthroscopy: instrumentation, general techniques, carpal joints, metacarpal and metatarsophalangeal joints, and tarsocrural joints. All the advances that have taken place in the field over the last decade are covered, particularly in the areas of postoperative management and rehabilitation. This trusted reference also provides an in-depth view of surgical procedures with new high-definition diagnostic and surgical arthroscopic images, as well as radiographs and composite illustrations. There is no better way to learn and master equine surgical procedures!

• Diagnostic images with side-by-side radiographs and illustrations offer multiple points of view and directional guidance on surgical procedures.
• Expert authorship features helpful insights and expertise from the worldwide leader and speaker on equine arthoscopy, Wayne McIlwraith.
• Specially commissioned artwork clearly illustrates local anatomy and key stages of surgical procedures.
• Coverage of choice, use, and maintenance of equipment provides a basic understanding of arthroscopic technique and reasoning behind various practices.
• Content dedicated to diagnostic and surgical arthroscopy of the horse provides authoritative, comprehensive information on this specialized subject.

• NEW! Updated high-definition images provide a crystal clear view of surgical procedures from multiple views.
• NEW! Companion website features 48 high-resolution digital videos that link back to the textbook for a vivid demonstration of surgical techniques.
• NEW! Expanded content ensures you are up to date on the latest developments in the field — particularly in the areas of tenoscopy, bursoscopy, and arthroscopic methods for cartilage repair.
• NEW! Chapter on postoperative management, adjunctive therapies, and rehabilitation procedures keeps you abreast of best practices when it comes to taking care of the horse post-operation.

Chapter 1

Introduction

Arthroscopic Surgery in the Horse—Advances Since 2005

Since 2005 magnetic resonance imaging (MRI) has become an important diagnostic technique in equine orthopedics. More specific diagnosis of conditions of soft tissues has led to further indications for diagnostic and surgical arthroscopy. There are limitations, however, and it has been demonstrated recently that the use of MRI for precise grading of the articular cartilage in human osteoarthritis (OA) is limited and that diagnostic arthroscopy remains the gold standard for grading cartilage damage, for a definitive diagnosis, and for decisions regarding therapeutic options in patients with OA (von Engelhardt et al, 2012).

Numerous publications have documented the use of electrosurgery, radiofrequency, and lasers within equine arthroscopic surgery. Clinical use of electrosurgery in the metacarpophalangeal and metatarsophalangeal joints for removal of fragments from the plantar margin of the proximal phalanx and proximal sesamoid bones (Bouré et al, 1999; Simon et al, 2004) desmotomy of the accessory ligament of the superficial digital flexor tendon (David et al, 2011) have been described. Thermal chondroplasty with radiofrequency energy (RFE) has been used frequently in humans and produces attractive visual effects, but multiple studies now suggest detrimental effects of RFE on articular cartilage (Cook et al, 2004; Lu et al, 2000, 2002) and in another study RFE was shown to exceed the damage obtained with mechanical debridement (Edwards et al, 2008). The use of radiofrequency probes for section and resection of soft tissues within joints, tendon sheaths, and bursae have also been described and may have a place in selected equine procedures (David et al, 2011; McCoy and Goodrich, 2011).

The use of intraarticular local analgesic agents to reduce the requirement for systemic anesthetic or analgesic agents, or both, has emerged. Evidence to support preoperative intraarticular administration of a combination of opiate and local anesthetic techniques have been provided in man (Hube et al, 2009), but opinions vary (Kalso et al, 2002; Rosseland, 2005). Toxicity of bupivacaine to bovine articular chondrocytes has been demonstrated (Chu et al, 2006), and in a second study bupivacaine, lidocaine or robivacaine were shown to have detrimental effects on chondrocyte viability in a dose- and duration-dependent manner (Lo et al, 2009). Using preoperative epidural morphine and detomidine has been reported to benefit horses undergoing experimental bilateral stifle arthroscopy (Goodrich et al, 2002).

In the carpus, arthroscopic approaches to the palmar aspect of the equine carpus have been detailed (Cheetham and Nixon, 2006), and comparison of magnetic resonance contrast arthrography and the arthroscopic anatomy of the equine palmar lateral outpouching of the middle carpal joint has also been described (Getman et al, 2007). Arthroscopically guided internal fixation of chip fractures of the carpal bones, which are of sufficient size and infrastructure, has been reported by Wright and Smith (2011). This technique can decrease morbidity associated with leaving large articular defects following removal.

New information in the metacarpophalangeal and metatarsophalangeal joints has included quantification of the amount of the articular surfaces of the metacarpal and metatarsal condyles that could be visualized with distal dorsal and distal palmar/plantar portals (Vanderperren et al, 2009). Declercq et al (2009) reported on fragmentation of the dorsal margin of the proximal phalanx in young Warmblood horses in which the majority underwent surgery for prophylactic reasons or to remove radiologic blemishes, or both. Osteochondral fragments within the dorsal plica have also been reported in Warmblood horses (Declercq et al, 2008). Impact fractures of the proximal phalanx in a filly have been described by Cullimore et al (2009) and the authors of this text have also seen similar lesions in the distal metacarpus.

In the palmar fetlock Byron and Goetz (2007) reported use of a 70-degree arthroscope to debride a subchondral bone defect in the distal palmar medial condyle of a third metacarpal bone; successful access to such lesions is generally limited. Schnabel et al (2006 and 2007) reported the results of arthroscopic removal of apical sesamoid fracture fragments in Thoroughbred racehorses with a higher success rate in horses that had raced previously. These authors also showed that removal when younger than 2 years of age gave comparable racing success to maternal siblings (Schnabel et al, 2007). Kamm et al (2011) evaluated the influence of size and geometry of apical sesamoid fragments following arthroscopic removal in Thoroughbreds and found no relationship to racing performance. Because 30% of the branches of insertion of the suspensory ligaments are subsynovial in the metacarpophalangeal/metatarsophalangeal joints, tears involving their dorsal surfaces can result in articular deficits and extrusion of disrupted ligament fibers into the synovial cavity; it has now been documented that such cases can be successfully treated with arthroscopic debridement (Minshall and Wright, 2006).

Further information has been recently published on fractures of the metacarpal and metatarsal condyles (Wright and Nixon, 2013; Jacklin and Wright, 2013) emphasizing the importance of articular congruency to outcome. Arthroscopically guided repair of midbody proximal sesamoid bone fractures was described, and results were reported by Busschers et al (2008), representing a substantial advance in the management of uniaxial fractures.

Recent developments in stifle arthroscopy have included publication of new and modified techniques, correlation of imaging modalities, and attempts to refine prognostic guidelines. In the femoropatellar joint, an arthroscopic approach has been described for the equine suprapatellar pouch (Vinardell et al, 2008). The use of a 10-mm diameter laproscopic cannula in the suprapatellar pouch for easier removal of debris and loose fragments has also been reported (McNally et al, 2011). Ultrasound has been noted to be a useful adjunct with femoropatellar osteochondritis dissecans (OCD) when there is high clinical suspicion but equivocal radiographic findings (Bourzac et al, 2009). A new concept of augmented healing of OCD defects has been introduced by Sparks et al (2011b), who used polydioxanone pins to reattach separat...