The effect of plate fixation on supination and pronation of the feline antebrachium: a model of pancarpal arthrodesis.

BACKGROUND: Pancarpal arthrodesis is purported to limit supination and pronation of the feline antebrachium. The objective of this study was to investigate whether plate fixation of the radius to the carpus and metacarpus limits supination and pronation of the ulna relative to the radius as a model for pancarpal arthrodesis in the cat. Eight feline cadaveric forelimbs were rotated from supination to pronation in a testing jig and CT (computed tomography) was performed in the neutral, supinated and pronated positions. A locking plate was then secured dorsally to the radius, radial carpal bone and metacarpal III of each of the limbs. CT was repeated in each of the testing positions following plate application. The radius and ulna of the control specimens, and the radius, ulna and plate of the plated specimens were then segmented using software. Alignment of the bones to the radius in the control specimens, and to the plate in the plated specimens was used to compare the changes in degrees of movement of the ulna relative to the radius in dorsal, sagittal and transverse planes. RESULTS: Based on the results of the paired t test, there was no significant difference in degrees of movement, or total range of motion between control and plated specimens in supinated and pronated testing conditions. CONCLUSION: The results of this ex-vivo study indicate that under the testing conditions employed, plate fixation of the radius to the carpus and metacarpus does not limit supination and pronation of the feline antebrachium.

Management of feline carpal injuries: What are the options and when is arthrodesis indicated?

PRACTICAL RELEVANCE: Feline carpal injuries are usually caused by falls from a height that result in hyperextension injury or antebrachiocarpal luxation or subluxation. Isolated ligamentous damage or fracture of the carpus is unusual; it is more common to have a combination of both in the cat. These injuries can be debilitating since cats climb and jump from great heights, and have a greater range of antebrachial pronation and supination than dogs. ANATOMY: There are differences in the anatomy of the feline and canine carpus. In particular, cats only have a single short radial collateral ligament, also known as the medial collateral ligament. This means that, in the cat, antebrachiocarpal subluxation is possible with rupture of the dorsal joint capsule and short radial collateral ligament alone. CLINICAL CHALLENGES: Many feline carpal injuries can be treated without performing pancarpal arthrodesis. However, determining which ligaments and joint levels are affected requires careful examination and often stress radiography. When pancarpal arthrodesis is performed in the cat, it has been reported to reduce the height of jumping and to increase reluctance to climb. This is speculated to be due to reduced pronation and supination movement of the carpus. EVIDENCE BASE: The current evidence base for management of feline carpal injuries is grade III or IV, with most of the studies being retrospective case series involving cadaveric dissection or direct extrapolation from published information about the dog. There are few guidelines regarding the optimal treatment options for carpal injuries in the cat.

Return to racing after surgical management of third carpal bone slab fractures in thoroughbred and standardbred racehorses.

OBJECTIVE: To determine the prognosis for racing of horses surgically treated for slab fractures of the third carpal bone (C3). STUDY DESIGN: Retrospective case study. ANIMALS: Horses (n = 125) surgically treated for C3 slab fractures. METHODS: Medical records of horses surgically treated for dorsal or sagittal C3 fractures were reviewed for age, sex, breed, limb, fracture type, degree of cartilage damage, and surgical treatment. Radiographs were evaluated to determine fracture depth, width, and displacement. Osteophytes, C3 lysis, and fragmentation were scored. Racing performance was obtained from online databases. Univariable and multivariable analyses were used to determine associations between independent variables and outcomes. RESULTS: Fifty-four (43%) horses raced postoperatively. Among thoroughbreds, 35% (30/86) with dorsal fractures and 63% (17/27) with sagittal fractures raced postoperatively. Among standardbreds, 77% (10/13) with dorsal fractures and 0% (0/2) with sagittal fractures raced postoperatively. Fracture displacement, C3 lysis, and cartilage damage affected the likelihood of racing postoperatively. Placement of 3.5-mm screws vs 4.5-mm screws and the placement of fewer screws were associated with improved likelihood of racing. CONCLUSION: The prognosis for postoperative racing of thoroughbreds with dorsal C3 fractures was less favorable than that previously reported. Concurrent joint pathology, such as cartilage damage at time of surgery, affected the ability of the horse to race postoperatively. CLINICAL SIGNIFICANCE: Although internal fixation of C3 slab fractures is required to restore joint congruity, return to racing should be expected in only 42% of thoroughbreds and 67% of standardbreds.

Antebrachiometacarpal arthrodesis in five dogs.

CASE REPORTS: Five dogs (4 with severe carpal contracture, 1 with a chronically infected carpal joint) underwent antebrachiometacarpal arthrodesis. Excision of all carpal bones, except the accessory carpal bone, was done, either because of persistent infection or to allow the manus to be arthrodesed in a functional position. All five dogs developed varying degrees of soft tissue swelling of the surgical site following surgery. All five arthrodeses achieved complete osseous union within 4-67 weeks. The immediate postoperative distal radiometacarpal frontal plane angulation ranged from 1° to 19° (mean ± SD: 7 ± 8°). The immediate postoperative distal radiometacarpal sagittal plane angulation ranged from 6° to 26° (mean ± SD: 17 ± 9°). Plate coverage of the secured metacarpal bone(s) ranged from 75% to 87% (mean ± SD: 80 ± 4%). Infection necessitated plate removal in four dogs, 3-17 (mean ± SD: 8 ± 6) months following surgery and 0-15 (mean ± SD: 5 ± 7) weeks following radiographic documentation of complete osseous union. CONCLUSION: Despite one dog having marked elbow incongruency and degenerative joint disease and one dog having an ipsilateral radial nerve deficit, all five dogs improved and had acceptable limb function at the time of the final evaluation, which ranged from 25 to 296 (mean ± SD: 99 ± 111) weeks following surgery.

Palmar arthroscopic approach and intra-articular anatomy of the bovine carpal joints.

OBJECTIVE: To describe the palmar arthroscopic approaches to the bovine carpus and document the visible intra-articular structures in each approach. STUDY DESIGN: Ex vivo study. SAMPLE POPULATION: Thirty fresh cadaveric bovine forelimbs. METHODS: Computed tomography (CT) and gross dissection were performed on 4 carpi. Latex models were produced from 6 carpi to define the gross anatomy and arthroscopic portals to the palmar carpal pouches. Ultrasonography and arthroscopy were performed on 20 carpi to document visualization of the local anatomy. RESULTS: A single palmar pouch was present on both sides of each joint on gross dissection and evaluation of latex models. The relationship between pouches and palmar structures was observed by CT. Small anechoic areas identified on ultrasonography increased after joint distension. Palmar arthroscopy of the antebrachiocarpal joint enabled visualization of the palmar surfaces of radial, intermediate, and ulnar carpal bones; distal radius; ulnar styloid process; palmar radiocarpal ligament; and articulation of accessory and ulnar carpal bones. Palmar arthroscopy of the middle carpal joint enabled inspection of the palmar aspects of ulnar, intermediate, radial, fused second and third and fourth carpal bones, palmar carpometacarpal ligament, and the short lateral collateral ligament. Palmar aspects of the fourth and fifth metacarpal bones were explored through the palmarolateral approach to the middle carpal joint. Instrument portals for each pouch were created under arthroscopic guidance. CONCLUSION: Palmar arthroscopy of the adult bovine carpus enabled visualization of the clinically relevant palmar intra-articular structures. CLINICAL SIGNIFICANCE: Palmar carpal arthroscopy should be considered as an adjunct to dorsal approach for the diagnosis and treatment of bovine carpal diseases.

Effect of bandaging techniques on sub-bandage pressures in the equine distal limb, carpus, and tarsus.

OBJECTIVE: To determine the influence of 3 types of bandages on sub-bandage pressures over the distal limb, carpus, and tarsus. STUDY DESIGN: Observational study. ANIMALS: Eight healthy horses. METHODS: Each of the 6 following bandages was applied on each horse in randomized order: (1) distal limb compression bandage (DLC), (2) double layer bandage (DL), (3) inner sanctum bandage (IS), (4) carpal compression bandage (CC), (5) tarsal compression bandage (TC), and (6) adhesive elastic carpal bandage (C-ELA). Sub-bandage pressures were measured with the Picopress compression measuring system (Microlab Electonica, Nicolo, Italy) after bandage application. Carpal and tarsal bandage pressures were assessed before and after walking the horses approximately 50 m. TC pressures were also measured after creating a slit over the calcaneus. A generalized linear model was used to test the association of pressure with sensor location, bandage type, time, and potential interactions (P < .05). RESULTS: DLC (165 mmHg) and IS (167 mmHg) generated greater mean combined pressures compared with DL (146 mmHg; P = .0166). At application, CC (154 mmHg) created higher mean combined sub-bandage pressure compared with C-ELA (70 mmHg; P < .001). Pressures resulting from CC and TC decreased after walking (P < .001), whereas those associated with C-ELA were not affected. CONCLUSION: Variations to the standard DLC construct did not increase sub-bandage pressures. CC and TC pressures rapidly decreased with ambulation, whereas C-ELA pressures in healthy horses were not affected by walking. CLINICAL SIGNIFICANCE: Variations to the standard DLC offer no additional benefit in regards to increasing sub-bandage pressures. Carpal elastic bandages maintain sub-bandage pressures during ambulation and may be more appropriate for long term bandaging in ambulating horses. Creating a slit over the calcaneal tuber in TC bandages is discouraged due to rapid decreases in sub-bandage pressure.

Pancarpal and partial carpal arthrodesis with 3 locking compression plates in 6 horses.

OBJECTIVE: To report the outcome of horses after pancarpal or partial carpal arthrodesis with 3 locking compression plates (LCP). STUDY DESIGN: Case series. ANIMALS: Six horses ranging in age from 8 months to 16 years and weighing 227-580 kg with severe carpal pathology including acute fractures, chronic osteoarthritis, and chronic angular limb deformity. METHODS: Pancarpal or partial carpal arthrodesis was performed with 3 LCP. Autologous cancellous bone grafts were used in 5 of 6 cases to facilitate joint arthrodesis. RESULTS: External coaptation was maintained for 4 to 6 weeks after surgery. Radiographic follow-up was available in all 6 cases, all of which reached arthrodesis and pasture soundness by 4-5 months postoperatively. One case required implant removal at 6 months because of implant exposure through the skin but returned to pasture soundness after removal. CONCLUSION: Carpal instability due to acute fractures or chronic disease was successfully stabilized with 3 short LCP, leading to pasture soundness in all 6 horses. CLINICAL SIGNIFICANCE: The use of 3 short LCP should be considered as a strategy to facilitate pancarpal or partial carpal arthrodesis by providing superior stability without placement of implants in the diaphysis of the radius and third metacarpus.

Bicipital Tendinopathy and Carpal Valgus Following a Distant Direct Thoracoabdominal Skin Flap in a German Shepherd with Necrotizing Fasciitis.

A 4 mo old German shepherd dog was presented following an acute onset lameness and swelling of the thoracic limb. Clinical signs, surgical findings, and culture results were consistent with a diagnosis of necrotizing fasciitis. Initial management consisted of extensive surgical debridement, wound lavage, and bandaging. Surgical closure was achieved with an axillary fold flap and distant direct single-pedicle thoracoabdominal flap. Three mo later, following deterioration of the lameness that was associated with carpal valgus, carpal subluxation, and tendinopathy of the distal radial insertion of the biceps brachii tendon, a closing wedge pancarpal arthrodesis and tenotomy of the biceps brachii tendon was performed. We hypothesize that extensive soft tissue trauma and subsequent fibrosis and tendon contracture following soft tissue reconstruction contributed to the complications seen. To the authors' knowledge, this is the first report of carpal valgus deformity and biceps brachii tendinopathy following a distant direct skin flap and axillary skin fold flap.

Augmentation of arthrodesis in dogs using a free autogenous omental graft.

A technique for using free autogenous omental grafting with arthrodesis in dogs is described and radiographic osseous union and complications after surgery are evaluated. This retrospective study matched body weight and procedure type for 8 cases of pancarpal arthrodesis, 4 cases of pantarsal arthrodesis, and 2 cases of partial tarsal arthrodesis in dogs with omental and cancellous bone autograft (OBG group) and with cancellous bone autograft alone (BG group). Radiographs were reviewed 9 to 12 weeks after surgery to compare scores of radiographic osseous union and it was found that the OBG group had higher scores than the BG group. The BG group had significantly more major complications that required re-operation for implant removal or treatment of a deep infection compared to the OBG group. Overall, free autogenous omental grafts may be used to augment arthrodesis in dogs without significant morbidity and further investigation of its use to reduce major complications and speed bone healing are warranted.

Augmentation de l'arthrodèse chez les chiens en utilisant une greffe omentale autogène libre. Cette étude décrit une technique de l'utilisation d'une greffe omentale autogène avec une arthrodèse chez les chiens et elle évalue l'union osseuse radiographique et les complications après la chirurgie. L'étude rétrospective a jumelé le poids corporel et le type d'intervention pour 8 cas d'arthrodèse pancarpienne, 4 cas d'arthrodèse pantarsienne et 2 cas d'arthrodèse partielle du tarse chez des chiens avec une autogreffe de l'os spongieux (groupe OBG) et avec une autogreffe de l'os spongieux seulement (groupe BG). On a évalué les radiographies de 9 à 12 semaines après la chirurgie pour comparer les notes d'union osseuse radiographique et on a constaté que le groupe OBG avait des notes supérieures à celles du groupe BG. Il s'est produit un nombre significativement supérieur de complications majeures dans le groupe BG qui ont exigé une nouvelle opération pour l'enlèvement de l'implant ou le traitement d'une infection profonde comparativement au groupe OBG. En général, les greffes omentales autogènes libres peuvent être utilisées pour augmenter l'arthrodèse chez les chiens sans morbidité significative et de nouvelles études de leur utilisation pour réduire les complications majeures et accélérer la guérison osseuse sont justifiées.(Traduit par Isabelle Vallières).

Pancarpal Arthrodesis Without Rigid Coaptation Using the Hybrid Dynamic Compression Plate in Dogs.

OBJECTIVE: To describe the complications, short- and long-term outcomes, and owner satisfaction for dogs treated with pancarpal arthrodesis (PCA) using the 2.7/3.5 mm locking and dynamic compression plate (DCP) hybrid pancarpal arthrodesis plate (hybrid DCP [HDCP]) without rigid coaptation in the postoperative period. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs with carpal injuries requiring PCA (n=15). METHODS: Records (May 2007-October 2013) of dogs that had PCA using 3.5/2.7 mm HDCP (1 or 2 plates) and a Robert-Jones bandage were reviewed to determine intra- and post-operative complications and overall limb function. Follow-up was obtained by clinical evaluation at our institution and telephone interview of owners. RESULTS: Fourteen dogs had PCA stabilized with a single HDCP and 1 giant breed dog had PCA stabilized with 2 HDCP on the dorsal aspect of the carpus secured onto the 3rd and 4th metacarpal bones. Two dogs presented with bilateral injuries. Thirteen owners (87%) judged the results of surgery as excellent and 2 (13%) judged the results of surgery as good. Minor complications (4 limbs; 23%) were occasional episodes of mild lameness in 3 dogs and 3 episodes of discharging sinus tracts in a single dog. Major complications (3 limbs; 17%) included 1 surgical site infection and implant failure in a 43 kg dog with an active leishmaniasis infection and a concurrent bilateral sacro-iliac luxation. Two dogs developed episodes of discharging sinus tract and pain over the most distal screw that eventually necessitated plate removal. CONCLUSION: PCA without rigid coaptation can successfully be performed using the HDCP.

Diagnostic endoscopy of the navicular bursa using a needle endoscope by direct or transthecal approach: A comparative cadaver study.

OBJECTIVES: To compare the practicability, visualization of structures, and iatrogenic damage of direct and transthecal approaches to the navicular bursa for diagnostic needle endoscopy. STUDY DESIGN: Descriptive study. SAMPLE POPULATION: Equine cadaver forelimbs (n = 30). METHODS: Direct and transthecal approaches for insertion of a needle endoscope into the navicular bursa were performed. Video recordings of endoscopic procedures were assessed to determine all structures visualized within the navicular bursa. Number of attempts to gain access to the navicular bursa and total time for insertion and examination were recorded. Distribution and severity of iatrogenic lesions were assessed and scored after dissection. RESULTS: There were no statistical differences for number of attempts or time needed for insertion and examination between direct and transthecal approaches. The direct approach offered significantly increased visibility of the ipsilateral abaxial and proximal margins of the navicular bone, and ipsilateral collateral sesamoidean ligament. Iatrogenic lesions were superficial and focal, regardless of approach taken, or whether a blunt or sharp trocar tip was used. CONCLUSIONS: The direct approach provided significantly better visualization of the ipsilateral structures within the navicular bursa compared to the transthecal approach. Needle endoscopy offers a reliable technique to evaluate the navicular bursa and may complement or replace other diagnostic modalities in horses with lameness localized to the navicular region.

Long-term follow-up of working dogs in New Zealand following pancarpal arthrodesis using dorsal hybrid plating.

AIM: To determine the long-term prognosis for working dogs in New Zealand following pancarpal arthrodesis (PCA) utilising a dorsal hybrid plate. METHODS: Owners of 14 dogs who had a PCA performed as part of a previous study conducted at two small animal veterinary surgical hospitals were contacted via phone and asked to participate in a short survey. RESULTS: A phone survey was completed for seven dogs. Five of the seven dogs had returned to full work, one dog had a moderate persistent lameness that prevented returning to normal work and the remaining dog did not return to normal work for reasons unrelated to the study. Removal of the implants was required in four of seven cases at a median interval of 2 (min 0.5, max 2) years following surgery. One dog had no gait abnormality, but developed an occasional mild lameness after jumping, one dog had a constant gait abnormality with a moderate, persistent lameness, and the remaining five dogs had a constant gait abnormality with a mild, intermittent lameness. All owners contacted were very satisfied with the procedure. CONCLUSIONS: Working dogs undergoing a standardised surgical procedure for unilateral PCA using a hybrid carpal arthrodesis bone plate applied dorsally have a good prognosis for return to work. CLINICAL RELEVANCE: Although this study has a small number of cases, this study provides subjective longer-term follow-up data than previously reported for working dogs that have undergone PCA. Owners should be warned that plate removal may be required in approximately 60% of dogs and additional expenditure should be planned for.

Arthroscopic removal of discrete palmar carpal osteochondral fragments in horses: 25 cases (1999-2013).

OBJECTIVE: To characterize discrete palmar carpal osteochondral fragmentation in horses and to document the effect of osteoarthritis and surgical removal of these fragments on functional outcome. DESIGN: Retrospective case series. ANIMALS: 25 horses. PROCEDURES: Medical records and radiographic views were reviewed to identify horses that had radiographic evidence of palmar carpal fragmentation, which was subsequently treated by arthroscopic removal. Information collected included cause of fracture, initial and long-term clinical and radiographic findings, and functional outcome. RESULTS: Palmar carpal fragmentation of 30 carpal bones was identified in 25 unilaterally affected horses. A known traumatic event was reported to cause the fragmentation in 17 of the 25 (68%) horses. Of the 25 horses, 17 (68%) had fragmentation involving the antebrachiocarpal joint, 7 (28%) had fragmentation involving the middle carpal joint, and 1 (4%) had fragmentation involving the carpometacarpal joint. The proximal aspect of the radial carpal bone was the most commonly affected site (12/30 fragments), followed by the accessory carpal bone (6/30). Of the 25 horses, 19 (76%) were not lame (sound) after surgery and returned to their intended use, 4 (16%) were considered pasture sound, and 2 were euthanized (because of severe postoperative osteoarthritis or long bone fracture during recovery from anesthesia). Eight of the 14 horses with preoperative evidence of osteoarthritis returned to function after surgery. Twelve of 17 horses with antebrachiocarpal joint fragments and 6 of 7 horses with middle carpal joint fragments returned to their previous use. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the prognosis for horses after arthroscopic removal of palmar carpal osteochondral fragments is good. Early intervention, before the development of osteoarthritis, is recommended.

Improvement in Bilateral Carpal Valgus Deviation in 9 Foals After Unilateral Distolateral Radial Periosteal Transection and Elevation.

OBJECTIVES: To evaluate the effect of periosteal transection and elevation in foals with naturally occurring carpal valgus deviation. STUDY DESIGN: Prospective clinical study. ANIMALS: Foals (n = 9) with bilateral carpal valgus. METHODS: Foals with bilateral carpal valgus had distolateral radial periosteal transection and elevation (PE) including distal ulnar transection on 1 limb. Foals were stall confined until the skin incisions healed, and then allowed free exercise in a small paddock or round pen. Dorsopalmar carpal radiographs were obtained at 14 day intervals to determine the carpal valgus angle (CVA) until it was <5°. RESULTS: All limbs had a reduction in CVA and there was no significant difference in total carpal valgus angular correction or the rate at which the correction occurred between the surgical and control limb. CONCLUSIONS: Unilateral distolateral radial PE had no effect on carpal angulation in 9 foals with naturally occurring bilateral carpal valgus deviation when performed between 19 and 43 days.

Partial carpal arthrodesis using a medially applied mini-plate in three cats with carpometacarpal hyperextension injury.

Hyperextension injury to the feline carpus usually results in disruption of the palmar ligament support at the level of the carpometacarpal joint. Treatment options include pancarpal or partial carpal arthrodesis. Partial carpal arthrodesis preserves range of motion of the antebrachiocarpal joint, and pronation and supination of the forearm. The surgical technique and three cases of partial carpal arthrodesis using medially applied mini-plates are described. Partial carpal arthrodesis of the feline carpus using medially applied mini-plates may be a safe and effective treatment for hyperextension injury to the carpometacarpal joints.

Ex vivo evaluation of carpal flexion after partial carpal arthrodesis in horses.

OBJECTIVE: To determine degrees of flexion after arthrodesis of the antebrachiocarpal (ABC) joint, middle carpal (MC), and carpometacarpal (CMC) joints combined (MC/CMC), and carpometacarpal (CMC) joint alone. STUDY DESIGN: Ex vivo study. ANIMALS: Forelimbs (n = 9) from 2- to 10-year-old Quarter Horses (5), Thoroughbred (2), and American Paint Horse (2). METHODS: Using 2 locking compression plates, 3 partial carpal arthrodesis techniques were performed. Cables and deadweights were connected to limbs and each angle of flexion determined 3 times using a protractor and then averaged. Control measurements were obtained before and after arthrodesis, the techniques randomized with Latin square design. Descriptive data were analyzed with Levene's test, Q-Q plots, ANOVA, and Bonferroni test. RESULTS: Mean ± SD carpal flexion results were: controls 150° ± 8°, CMC arthrodesis 149° ± 9°, MC/CMC arthrodesis 43° ± 7.6°, and ABC arthrodesis 25° ± 6.3°. There was no significant reduction in flexion after a CMC arthrodesis compared with controls (P = .21), but there was after ABC (P < .001) and MC/CMC arthrodesis (P < .001), with the ABC arthrodesis significantly reduced compared with an MC/CMC arthrodesis (P < .001). CONCLUSIONS: Whereas CMC arthrodesis does not affect carpal flexion, CMC/MC and ABC arthrodesis markedly reduce the degree of carpal flexion.

Clinical comparison of the hybrid dynamic compression plate and the castless plate for pancarpal arthrodesis in 219 dogs.

OBJECTIVE: To describe and compare a large population of dogs that had pancarpal arthrodesis (PCA) using either a hybrid dynamic compression plate (HDCP) or a CastLess Plate (CLP). STUDY DESIGN: Multicenter, retrospective, cohort study. ANIMALS: Dogs (n = 240; 261 PCA). METHODS: Medical records (2000-2012) from 12 UK orthopedic centers were reviewed for dogs that had PCA to document signalment, diagnosis, arthrodesis method, and complication rates. Follow-up data were used to compare outcome (lameness evaluation and radiographic healing) after use of HDCP and CLP plates. RESULTS: PCA was performed with HDCP in 125 cases, CLP in 105, and by other techniques in 31. Carpal hyperextension injury was the most common diagnosis in HDCP and CLP groups. Surgical site infection (18.3%) was the most common postoperative complication. There was no difference in intra- (11% HDCP, 21% CLP) or postoperative (34% HDCP, 41% CLP) complication rates. Use of external coaptation did not affect postoperative complication rates or outcome. External coaptation related complications occurred in 32% HDCP and 18% CLP (P = .02). At median follow-up, most dogs were classified as having no or mild lameness (73% HDCP, 83% CLP) and there was radiographic healing in 40% HDCP and 46% CLP (P = .8) cases. CONCLUSIONS: CLP and HDCP may both be used successfully to achieve pancarpal arthrodesis. Adjunctive external coaptation does not appear to have a measurable clinical benefit but is associated with morbidity.

Second carpal bone slab fracture and subluxation of the middle carpal joint in a horse subsequent to arthrodesis of the carpometacarpal joint.

OBJECTIVE: To report complications of arthrodesis of the carpometacarpal (CMC) joint using a drilling technique in an adult horse. STUDY DESIGN: Case report. ANIMALS: Horse (n = 1). METHOD: A 12-year-old Quarter Horse mare with CMC osteoarthritis (CMC-OA) had arthrodesis under general anesthesia in right lateral recumbency. Under fluoroscopic guidance, a 4.5 mm drill bit was inserted at 3 drilling sites 5-6 cm into the CMC joint and was fanned 30-45° in the plane of the joint and 5-10° in the long axis of the limb to destroy articular cartilage and expose the subchondral bone. RESULTS: The horse presented 2 weeks after surgery for severe lameness of the operated limb. A slab fracture of the 2nd carpal bone (C2) and subluxation of the middle carpal (MC) joint was diagnosed. The horse was humanely euthanatized due to poor prognosis. CONCLUSION: The fanning technique of arthrodesis of the CMC joint may lead to fracture of carpal bones, joint instability, and MC joint subluxation. A balance between articular surface destruction and maintenance of joint stability should be achieved when using this technique.