Intraperitoneal bupivacaine with or without incisional bupivacaine for postoperative analgesia in dogs undergoing ovariohysterectomy.

OBJECTIVE: Intraperitoneal (IP) bupivacaine provides postoperative analgesia in dogs undergoing ovariohysterectomy (OHE) alone or in combination with incisional (INC) bupivacaine. This study investigated whether the combination of INC and IP bupivacaine is superior to IP bupivacaine alone. STUDY DESIGN: Prospective, randomized, blinded clinical study. ANIMALS: Thirty-nine privately owned dogs undergoing OHE, aged 25 ± 23 months and weighing 11.8 ± 5.7 kg. METHODS: Dogs were premedicated with acepromazine (0.05 mg kg(-1) ) and morphine (0.5 mg kg(-1) ) intramuscularly (IM); anaesthesia was induced with propofol and maintained with isoflurane in oxygen. Carprofen (4 mg kg(-1) ) was administered subcutaneously (SC) after intubation. Bupivacaine (3 mg kg(-1) ) IP was administered before complete closure of the linea alba to all dogs. Dogs were randomly assigned into two groups: group B received bupivacaine (n = 20; 1 mg kg(-1) ) and group S received saline (n = 19; 0.2 mL kg(-1) ) INC as a subcutaneous 'splash' before skin closure. Postoperative analgesia was assessed with a dynamic interactive visual analogue scale, the short form of the Glasgow Composite Pain Scale, and mechanical nociceptive threshold (MNT) measurement at 0.5, 1, 2, 4, 6, 8, 12 and 20 hours after surgery by one blinded observer. Parametric data were tested using t-test; nonparametric data were analysed using the two-sample Wilcoxon test (p < 0.05). RESULTS: There was no significant difference between groups with regard to age, weight, surgical and anaesthetic duration, incision length, sedation and pain scores. MNT values decreased in both groups at all time points as compared with the baseline. No dog required rescue analgesia. No postoperative complications were observed. CONCLUSION AND CLINICAL RELEVANCE: Bupivacaine IP and carprofen SC after morphine IM did provide satisfactory postoperative analgesia in dogs undergoing OHE with the anaesthetic protocol used. There appears to be no clinical advantage to adding bupivacaine INC. Neither protocol could prevent the development of primary hyperalgesia.

The Advanced Locking Plate System (ALPS): a retrospective evaluation in 71 small animal patients.

OBJECTIVE: To evaluate use of the Advanced Locking Plate System (ALPS) in dogs and cats and report outcome. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs (n = 29) and cats (n = 42). METHODS: The medical records (April 2007-April 2010) of dogs and cats treated with ALPS were reviewed evaluated. Data retrieved included signalment, indication for surgery, complications, and outcome. RESULTS: ALPS was used for 54 fractures, 12 tarsal or carpal ligament injuries and in 6 cases, to prevent or treat fractures during total hip replacement. Complications needing revision surgery occurred in 4 cases (5.5%): fixation failure was identified in 3 (2 fracture-fixations, 1 pancarpal arthrodesis), and a fracture occurred through a screw hole. The most common complication after tarsal arthrodesis was suture dehiscence. All cases had healed by study end. CONCLUSIONS: ALPS offers a reliable alternative for fracture treatment and some other orthopedic conditions in small animals.

Minimally invasive repair of meta-bones.

Metacarpal and metatarsal fractures are common injuries in small animals and, in most of the cases, can be treated by minimally invasive techniques. Bone plates applied through epi-periosteal tunnels can stabilize meta-bones. Meta-bones III and IV are stabilized by dorsally applied plates. Meta-bones II and V are stabilized using plates applied medially and laterally. The scarcity of soft tissue coverage and the simple anatomy of meta-bones make these fractures amenable to fixation by using minimally invasive techniques. This practice should reduce morbidity and enhance healing time.

Effect of external rotational humeral osteotomy on the contact mechanics of the canine elbow joint.

OBJECTIVE: To evaluate the effect of 15° external rotational humeral osteotomy (ERHO) on canine elbow joint contact mechanics. STUDY DESIGN: Ex vivo biomechanical study. SAMPLE POPULATION: Unpaired cadaveric canine thoracic limbs (n = 8) METHODS: Digital pressure sensors placed in a subchondral osteotomy distal to the elbow joint were used to measure contact area, peak and mean contact pressure, peak pressure location, center of pressure, and total force in the subchondral bone of the radius and the ulna. Measurements were taken in the following sequence: (i) neutral and (ii) after 15° external rotation. The distal aspect of the humerus was externally rotated by a middiaphyseal osteotomy and stabilized with an internal fixator. Data were normalized and analyzed using paired t-tests; P ≤ .05 was considered significant. RESULTS: Peak pressure location and center of pressure shifted 37.5 ± 15.9% and 21.5 ± 6.8% laterally after ERHO (P < .001 for both). Both were situated over the subchondral bone of the ulna in neutral position and over the radius after rotation in all 8 specimens (P < .001). Pressure measured in the ulnar part of the osteotomy was reduced from 58.7 ± 9.1% to 27.1% after ERHO (P < .001). Contact area, peak and mean contact pressure, and total force did not vary significantly between conditions. CONCLUSION: ERHO shifts the peak pressure location and the center of pressure laterally, toward the radial head and reduced the pressure acting on the ulna. The lateral shift of peak pressure may be beneficial in dogs with medial compartment disease.

Comparison between a novel bovine xenoimplant and autogenous cancellous bone graft in tibial tuberosity advancement.

OBJECTIVE: To compare radiographic healing and clinical outcome of a frontal-opening wedge osteotomy of canine tibiae when the osteotomy site is packed with either a novel bovine xenograft or standard autogenous cancellous bone graft (ACBG). STUDY DESIGN: Cohort study. ANIMALS: Dogs (n = 82) with partial or complete rupture of the cranial cruciate ligament that had tibial tuberosity advancement (TTA). METHODS: In 48 dogs, the osteotomy was packed with a novel bovine xenograft and in 34 dogs, ACBG was used. Eight week postoperative radiographs from both groups were graded for osteotomy healing using a 0-4-point scale. Data were analyzed using a Mann-Whitney test with significance set at P < .05. RESULTS: Thirty-four dogs (39 stifles) with xenoimplants had complete records and radiographic follow-up at 8 weeks. No significant differences between xenografting and autografting were identified in grading of osteotomy fill, osteointegration, or healing of the distal osteotomy. Significant differences were noted in grading of osteotomy healing proximally (autograft > xenoimplant) and of opacity in the osteotomy site (xenoimplant > autograft). CONCLUSIONS: Radiographic evidence of healing of the xenoimplanted portion of the TTA osteotomy was equivalent to results with ACBG. Healing of the proximal osteotomy site (above the cage) was improved when ACBG was used as the graft.

Intraoperative contamination of the suction tip in clean orthopedic surgeries in dogs and cats.

OBJECTIVE: To (1) determine suction tip (intermittent and continuous mode) contamination rate in orthopedic surgery in dogs and cats; (2) examine the effect of surgical time on contamination; and (3) report bacteria isolated. STUDY DESIGN: Clinical study. SAMPLE POPULATION: Clean orthopedic surgeries (n = 50). METHODS: Surgical procedures were assigned to 1 of 2 groups: (1) continuous (n = 25) or (2) intermittent suction (n = 25). A control suction was operated in each surgery. Samples for aerobic and anaerobic bacteriologic examination were collected from the surgical suction at 0, 20, 60 minutes, and at the end of surgery, and from the control suction at the end of the surgery only. Comparison of continuous and intermittent suction data, and the effect of surgical time on contamination rate were analyzed using a Kaplan-Meier survival analysis followed by a Cox proportional hazards model. P < .05 was considered significant. RESULTS: Aerobic contamination occurred in 22 of 50 surgical procedures and there was no anaerobic growth. There was no significant difference between continuous and intermittent suction mode groups (P = .40). Surgical time did not influence the contamination rate (P = .79). Bacterial cultures mainly revealed coagulase-negative Staphylococci, however multiresistant bacteria were isolated. CONCLUSIONS: We failed to find superiority of the intermittent operation mode of the suction tip over the continuous mode. A safe time frame before contamination of the suction tip occurs that could not be defined.

Effect of tibial tuberosity advancement on the contact mechanics and the alignment of the patellofemoral and femorotibial joints.

OBJECTIVE: To evaluate the effect of tibial tuberosity advancement (TTA) on patellofemoral (PF) contact mechanics, and alignment of the PF and femorotibial (FT) joints in cranial cruciate ligament (CrCL)-deficient stifles of dogs. STUDY DESIGN: Ex vivo biomechanical study. ANIMALS: Unpaired cadaveric hind limbs (n=9). METHODS: Digital pressure sensors placed in the PF joint were used to measure contact force, contact area, peak and mean contact pressure, and peak pressure location with the limb under an axial load of 30% body weight and a stifle angle of 135°. The FT and PF poses were obtained using a 2-dimensional computer digitization technique. Each specimen was tested under normal, CrCL-deficient, and TTA-treated conditions. Data was normalized and analyzed, after testing for normality by Wilk-Shapiro, using 1 sample T-test, paired T-test, and ANOVA; P≤.05 was considered significant. Bonferroni's correction was used when needed. RESULTS: A significant cranioproximal tibial displacement and increase in patellar tilt were found in the CrCL-deficient joints. Both FT and PF alignments were restored after TTA. Contact areas and peak pressure did not vary between conditions. Peak pressure location displaced proximally from intact to CrCL-deficient condition and returned to normal after TTA. Total force measured in the CrCL-deficient stifle and TTA conditions were significantly lower than in the control. CONCLUSION: TTA restored the normal FT and PF alignment, and reduced the retropatellar force by about 20%.

Radiographic and ultrasonographic evaluation of the patellar ligament following tibial tuberosity advancement.

Effect of tibial tuberosity advancement (TTA) on the patellar ligament has not been described. Our purpose was to evaluate the patellar ligament radiographically and ultrasonographically before and after a TTA. Twenty-one stifles (20 dogs) were evaluated preoperatively (T0), and at six (n=18) (T1) and 16 weeks (n=17) (T2) postTTA. Radiographically, proximal and distal thickness of the patellar ligament was assessed and a ratio to the total length of the ligament was calculated to compensate for the magnification. Ultrasound evaluation included measurements of the transverse thickness and cross-sectional area at three different levels, as well as a subjective score of ligament changes. In comparison with T0, all radiographic and ultrasonographic measurements increased significantly, 6 weeks postoperatively (P≤0.04), and did not change 16 weeks postoperatively compared with T1. The subjective score worsened significantly from T0 to T1 and T0 to T2 (P<0.0001), and improved significantly from T1 to T2 (P=0.02). Larger cage size was associated with a more severe increase in radiographic proximal thickness to total length ratio and ultrasonographic middle transverse area at both follow-up examinations (P0.02). Dogs in which arthrotomy was not performed appeared to have ultrasonographically less changes. In conclusion, patellar desmopathy was a common postoperative sequel to TTA. Surgical trauma, arthrotomy, perfusion injury, complete vs. partial cranial cruciate ligament rupture, larger tibial advancement, postoperative activity or altered insertion angle of the patellar ligament at the tibial tuberosity are suggested causes, that should be elucidated in a larger study cohort.

Comparison of healing of the osteotomy gap after tibial tuberosity advancement with and without use of an autogenous cancellous bone graft.

OBJECTIVE: To evaluate and compare healing, with and without the use of bone graft, of the gap created during tibial tuberosity advancement (TTA). STUDY DESIGN: Prospective study and case series. ANIMALS: Dogs treated with TTA (n=67). METHODS: Prospective study: Mediolateral radiographic projections (6 weeks and 4 months) after TTA without use of bone graft (group I, n=14) were compared with radiographs of consecutive TTA in which the gap was filled with autologous cancellous bone graft (group II, n=14). Two scoring techniques (A, B) were used. Score A was used to grade the overall osteotomy healing (0=no healing, 4=healed osteotomy). Score B evaluated, independently of each other, healing in 3 sites: proximal to the cage (B1), between cage and plate (B2), and distal to the plate (B3). CASE SERIES: nongrafted TTA (4-25 weeks, n=39) were evaluated for healing (Score A). Data was analyzed using t-tests and ANOVA. Significance was set at P≤.05. RESULTS: Prospective study: Score A, B2, and B3 showed no difference in healing between groups at 6.8 weeks and 4.2 months. Score B1 revealed, in both rechecks, a significantly higher density in group II. case series: Radiographs at 11.59±5.99 weeks scored 3.3 (2-4). No healing related complications were observed. CONCLUSION: The osteotomy gap created during TTA healed within expected time regardless of bone graft use.

Zurich cementless total hip replacement: retrospective evaluation of 2nd generation implants in 60 dogs.

OBJECTIVE: To evaluate the results of application, and identify complications, of the 2nd generation of Zurich Cementless Total Hip Replacement (ZCTHR). STUDY DESIGN: Case series. ANIMALS: Client-owned dogs (n=60) that had ZCTHR (n=65). METHODS: Dogs with ZCTHR (2001-2003) with a minimum follow-up > or =6 months were evaluated. Data included signalment, cup position, longest follow-up, complications, management of complications and outcome. RESULTS: Mean follow-up was 22.68 months. Eleven cases (17%) had postoperative complications: femoral fracture (n=1; 1.5%), prosthesis luxation (7; 11%), cup loosening (2; 3%), and implant failure (1; 1.5%); 9 cases were successfully revised. Explantation of implants was performed in 1 case because of infection, and 1 dog was euthanatized after reluxation. CONCLUSIONS: ZCTHR can restore function in dogs affected by disabling diseases of the coxofemoral joint. The press-fit fixation of the cup allowed for corrections in cases of incorrect positioning. Cases with aseptic loosening were revised successfully by impacting larger cups. Newer stems of this generation are shot peening treated to increase their resistance to breakage. In our cases, infection is a disastrous event, leading to implant removal. After resolution of complications, a successful final outcome was achieved in 97% of THR. CLINICAL RELEVANCE: ZCTHR offers a reliable alternative for treating dogs with disabling diseases of the hip joints.

Effect of conformation of the distal portion of the femur and proximal portion of the tibia on the pathogenesis of cranial cruciate ligament disease in dogs.

OBJECTIVE: To evaluate mediolateral radiographic views of stifle joints to identify conformational differences between athletically sound dogs and dogs with cranial cruciate ligament disease (CCLD). SAMPLE POPULATION: Radiographic images of 50 stifle joints of 43 dogs with surgically confirmed CCLD and 50 stifle joints of 38 dogs without clinical signs of stifle joint disease. PROCEDURES: Mediolateral radiographic views of stifle joints were obtained, and long axes of the femur, tibia, and femoral condyles were measured. Angles between long axes of the femur and femoral condyle and between long axes of the femur and tibia were measured. Circles were drawn representing the joint surface of femoral condyles (circle 1), area of contact on the tibial plateau (circle 2), and femoral trochlea (circle 3). Radii of circles 1, 2 (line F), and 3 were measured. Distances between midpoints of circles 1 and 2 (line K) and between midpoint of circle 2 and most cranial aspect of the tibial tuberosity (line G) were measured. To evaluate differences in conformation that could lead to CCLD, quotients derived from measurements were created for comparison; angles were compared between dog groups. RESULTS: Significant differences were found in the quotients created by the lengths of lines G and F and lines G and K between dogs with and without CCLD. CONCLUSIONS AND CLINICAL RELEVANCE: No anatomic differences were detected in the distal portion of the femur between dogs with and without CCLD. Development of the tibial tuberosity and shape (convexity) of tibial condyles may be relevant in the pathogenesis of CCLD.

Medial plating for carpal panarthrodesis.

OBJECTIVE: To describe a technique for carpal panarthrodesis using a medially applied dynamic compression plate (DCP) and to evaluate outcome. STUDY DESIGN: Retrospective study. ANIMALS: Nine dogs with 10 carpal joint injuries. METHODS: Medical records of dogs that had carpal panarthrodesis by medial application of a DCP were reviewed. Signalment, cause and type of injury, preoperative treatment, operative technique, and postoperative clinical and radiographic outcome were retrieved. RESULTS: Screw loosening in the metacarpal bones required surgical revision in 3 dogs. The plate was removed because of lick dermatitis in another dog. No complications were observed in 6 arthrodeses. All dogs were subsequently sound. CONCLUSIONS: Medial application of a DCP is a reliable, reproducible method for carpal panarthrodesis. The load on the edge of the plate provides an increased area moment of inertia of the plate, enhancing it resistance to bending forces. Because of the valgus standing position of the canine carpus, dynamic compression is achieved. The DCP is secured to 1-3 metacarpal bones and loosening of the implant and bone fractures are expected to occur less frequently. CLINICAL RELEVANCE: Medial plating for carpal panarthrodesis is a valid alternative method that can be used in dogs with injuries to the carpus for which panarthrodesis of the carpal joint is indicated.