Geometric, landmark-guided technique reduces tissue trauma, surgery time, and subjective difficulty for canine peripheral lymphadenectomies: an educational crossover study.

OBJECTIVE: To compare the effect of a geometric, landmark-guided lymphadenectomy (LL) approach to peripheral lymph nodes (LNs) on successful LN identification, surgical time, tissue trauma, and ease of LN identification compared to standard lymphadenectomy (SL) and methylene blue-guided lymphadenectomy (MBL). SAMPLE: 18 adult, mixed-breed canine cadavers operated on by 7 veterinarians and 5 fourth-year veterinary students between July 23 and October 12, 2022. METHODS: Participants were provided standardized, publicly available materials regarding the anatomy and surgical techniques for SL of 3 peripheral lymphocentrums: superficial cervical, axillary (ALN), and superficial inguinal (SILN). Participants performed the 3 SLs unilaterally on canine cadavers. Thereafter, they were randomly assigned to 2 crossover groups: MBL and LL. All dissections were separated by at least 2 weeks for each participant. Primary outcome measures included successful LN identification, surgical time, tissue trauma scores, and subjective difficulty. RESULTS: Successful LN identification was highest with LL (86%) compared to SL (69%) and MBL (67%). Subjective difficulty scores were reduced with LL for SILN dissections. Tissue trauma scores were reduced when using LL for ALN and SILN compared to MBL and SL. Time to LN identification was reduced for ALN with LL. No significant differences were observed between MBL and SL, or for the superficial cervical dissections. CLINICAL RELEVANCE: Peripheral lymphadenectomies are time consuming and difficult for veterinarians in early stages of surgical training. Little surgical guidance is provided within current literature. Geometric, landmark-guided lymphadenectomies may improve LN identification success and reduce surgical time, tissue trauma, and procedure difficulty, which could encourage their clinical application.

Radiographic Comparison of Virtual Surgical Corrective Options for Excessive Tibial Plateau Angle in the Dog.

OBJECTIVE: The main aim of this study is to compare the impact of six proximal tibial osteotomies on the geometry and alignment of tibias with and without excessive tibial plateau angle (TPA). STUDY DESIGN: Mediolateral radiographs of 30 canine tibias were divided into three groups (n = 10/group): moderate TPA (≤34 degrees), severe TPA (34.1-44 degrees) and extreme TPA (>44 degrees). Six proximal tibial osteotomies were simulated on each tibia using orthopaedic planning software: cranial closing wedge ostectomy (CCWO), modified CCWO (mCCWO), isosceles CCWO (iCCWO), neutral isosceles CCWO (niCCWO), tibial plateau levelling osteotomy with CCWO (TPLO/CCWO) and coplanar centre of rotation of angulation-based levelling osteotomy (coCBLO). All tibias were reduced to a standard target TPA. Pre- and postoperative measurements were obtained for each virtual correction. Compared outcome measures included tibial long axis shift (TLAS), cranial tibial tuberosity shift (cTTS), distal tibial tuberosity shift (dTTS), tibial shortening and osteotomy overlap. RESULTS: Across all TPA groups, TPLO/CCWO had the lowest mean TLAS (1.4 mm) and dTTS (6.8 mm); coCBLO had the largest TLAS (6.5 mm) and cTTS (13.1 mm); CCWO had the largest dTTS (29.5 mm). CCWO had the largest degree of tibial shortening of 6.5 mm, while mCCWO, niCCWO and coCBLO resulted in minimal tibial lengthening (1.8-3.0 mm). These trends were generally conserved across different TPA groups. All findings had a p-value less than 0.05. CONCLUSION: mCCWO balances moderate alterations to tibial geometry while preserving osteotomy overlap. The TPLO/CCWO has the least effect on tibial morphology alteration, whereas the coCBLO results in the largest alteration.

Superficial anatomic landmarks can be used to triangulate the location of canine peripheral lymphocentrums: superficial cervical, axillary, and superficial inguinal.

OBJECTIVE: To utilize the geometry of superficial anatomic landmarks to guide incisional location and orientation for peripheral lymphadenectomy, document deep anatomic landmarks for lymphocentrum identification, and develop novel surgical approaches to the superficial cervical, axillary, and superficial inguinal lymphocentrums in dogs. ANIMALS: 12 canine cadavers. PROCEDURES: 2 cadavers were used for a pilot investigation to determine optimal body positioning, select superficial anatomic landmarks for lymphocentrum identification, and evaluate novel surgical approaches to the 3 lymphocentrums. These lymphocentrums were then dissected in 10 additional cadavers using these novel surgical approaches. Measurements of the distances from lymphocentrum to landmark and between landmarks were obtained for each lymphocentrum. Deep anatomic landmarks were recorded for each dissection. The mean and SD were calculated for each measurement and used to develop geometric guidelines for estimating the location of each lymphocentrum for these surgical approaches. RESULTS: Each peripheral lymphocentrum was found in the same location relative to the respective, predetermined, superficial, anatomic boundaries in all cadavers. Briefly, the superficial landmarks to each lymphocentrum were as follows: (1) superficial cervical: wing of atlas, acromion process of scapula, greater tubercle of humerus; (2) axillary: caudal border of transverse head of superficial pectoral muscle, caudal triceps muscle, ventral midline; and (3) superficial inguinal: origin of pectineus muscle, ipsilateral inguinal mammary gland, ventral midline. The proposed superficial and deep surgical landmarks were identified within every cadaver. The previously undescribed surgical approaches were effective for lymphocentrum identification. CLINICAL RELEVANCE: Anatomic landmarks provided in this study may help reduce surgical time and tissue trauma during peripheral lymphadenectomy in dogs. This study was also the first to describe a surgical approach to the superficial inguinal lymphocentrum and ventral approaches to the superficial cervical and axillary lymphocentrums and provided previously unpublished anatomic landmarks for a lateral approach to the superficial cervical lymphocentrum.

Radiographic and Biomechanical Assessment of Three Implant Designs for Canine Cementless Total Hip Replacement.

OBJECTIVE: The aim of this study was to evaluate the relationship between radiographic fit/fill measurements and biomechanical performance of three canine cementless total hip implant designs using an in vitro biomechanical testing protocol that replicates compression and torsion. STUDY DESIGN: Eighteen (six/group) canine cadaveric femurs were implanted with one of three cementless total hip implant designs: (1) collarless, (2) collared or (3) lateral bolt stems. Femoral length, canal flare index (CFI), canal fill, stem fit, stem level and stem angle were measured as independent variables. Biomechanical performance was tested using physiological, non-destructive gait loading (loading protocols) and destructive testing (failure protocols). RESULTS: During loading protocols, compressive stiffness was influenced by stem level (p < 0.05) and torsional stiffness was influenced by stem level and CFI for collarless stems (p < 0.05). During failure protocols, peak load was influenced by mediolateral (ML) stem angle (p < 0.05) and CFI (p < 0.01) for collarless stems and CFI for lateral bolt stems (p < 0.05). Peak torque was influenced by ML stem angle, craniocaudal stem angle and CFI for collarless stems (p < 0.05) and average ML fill for collared stems (p < 0.05). CONCLUSION: Biomechanical performance of collarless stems in cementless hip arthroplasty is more impacted by radiographic fit/fill than lateral bolt and collared stems. As a result, collarless stems may be more dependent on preoperative fit and intraoperative precision.