To compare use of a 3-level self-locking suture (3LSLS) technique with use of a previously described modified 3-loop pulley (M3LP) technique to repair rupture of the proximal aspect of patellar tendons in limbs from canine cadavers.
Paired hind limbs of 6 adult mixed-breed dogs.
A limb from each pair was randomly assigned to be repaired by the 3LSLS technique or M3LP technique with size-2 ultrahigh-molecular-weight polyethylene and size-0 monofilament polypropylene suture, respectively. Limbs were prepared, and each patellar tendon was transected at a site chosen to simulate rupture at the proximal aspect. Tendons were repaired with the assigned techniques and mechanically tested with a biaxial servohydraulic test system; the clamp was distracted until the repair failed. Force at 1 -mm gap formation, 3-mm gap formation, and repair failure and gap size at failure were measured and compared between methods. Mode of failure was recorded.
There was no significant difference between methods for the force required to produce a 1 - or 3-mm gap in the repair. The 3LSLS technique required a significantly higher load for complete failure; gap formation immediately before failure was significantly greater for this method than for the M3LP technique. Four of 6 repairs with the M3LP technique and 0 of 6 repairs with the 3LSLS technique failed by suture breakage.
CONCLUSIONS AND CLINICAL RELEVANCE
The 3LSLS technique with size-2 ultrahigh-molecular-weight polyethylene suture was as effective at resistance to 1 - and 3-mm gap formation as the M3LP with size-0 monofilament polypropylene suture.
OBJECTIVE To determine the effect of arthrotomy alone or in combination with osteotomy of the proximal portion of the tibia on blood delivery to the patellar tendon of dogs.
SAMPLE 24 canine cadavers.
PROCEDURES One hind limb from each cadaver was assigned to 1 of 4 treatment groups: medial arthrotomy (MA; MA group), lateral arthrotomy (LA; LA group), MA and LA with tibial tuberosity transposition (MALA group), and MA with tibial plateau leveling osteotomy (TPLO; TPLO group). The contralateral hind limb served as the control sample. Contrast solution (barium [33%], India ink [17%], and saline [0.9% NaCl] solution [50%]) was injected through an 8F catheter inserted in the caudal portion of the abdominal aorta. Limbs were radiographed to allow examination of vascular filling. The patella, patellar tendon, and tibial crest were harvested, radiographed to allow examination of tissue vascular filling, and fixed in 4% paraformaldehyde. Vessels perfused with contrast solution were counted in sections obtained from the proximal, middle, and distal regions of each patellar tendon.
RESULTS Vessel counts did not differ significantly among the 3 tendon regions. Compared with results for the control group, delivery of contrast solution to the patellar tendon was significantly decreased in the MALA and TPLO groups but was not changed in the MA or LA groups.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that surgical procedures used to treat cranial cruciate injuries (ie, TPLO) and patellar luxation decreased blood delivery to the patellar tendon of canine cadavers, at least acutely.
Objective—To compare the mechanical properties of laryngeal tie-forward (LTF) surrogate constructs prepared with steel fixtures and No. 5 braided polyester or braided polyethylene by use of a standard or a modified suture placement technique.
Sample—32 LTF surrogate constructs.
Procedures—Surrogate constructs were prepared with steel fixtures and sutures (polyester or polyethylene) by use of a standard or modified suture placement technique. Constructs underwent single-load-to-failure testing. Maximal load at failure, elongation at failure, stiffness, and suture breakage sites were compared among constructs prepared with polyester sutures by means of the standard (n = 10) or modified (10) technique and those prepared with polyethylene sutures with the standard (6) or modified (6) technique.
Results—Polyethylene suture constructs had higher stiffness, higher load at failure, and lower elongation at failure than did polyester suture constructs. Constructs prepared with the modified technique had higher load at failure than did those prepared with the standard technique for both suture materials. All sutures broke at the knot in constructs prepared with the standard technique. Sutures broke at a location away from the knot in 13 of 16 constructs prepared with the modified technique (3 such constructs with polyethylene sutures broke at the knot).
Conclusions and Clinical Relevance—Results suggested LTF surrogate constructs prepared with polyethylene sutures or the modified technique were stronger than those prepared with polyester sutures or the standard technique.
To compare joint stability and ultimate strength among 4 prosthetic ligament constructs for repair of tarsal medial collateral ligament (MCL) injury in dogs.
13 canine cadavers (26 hind limbs).
Each limb was stripped of all soft tissues except those associated with the tarsal joint and assigned to 1 of 4 prosthetic ligament constructs. The AN construct consisted of 3 bone anchors connected with monofilament nylon suture. The AU construct consisted of low-profile suture anchors connected with multifilament ultrahigh-molecular-weight polyethylene (UHMWPE) suture. The TN and TU constructs involved the creation of 3 bone tunnels and use of nylon or UHMWPE suture, respectively. Each limb underwent biomechanical testing before and after MCL transection and before and after cyclic range-of-motion testing following completion of the assigned construct. Tarsal joint stability (extent of laxity) was assessed with the joint in each of 3 positions (75°, 135°, and 165°). After completion of biomechanical testing, each limb was tested to failure to determine the ultimate strength of the construct.
Relative to intact tarsal joints, joint laxity was significantly increased following completion of all 4 constructs. Construct type was not associated with the magnitude of change in joint laxity. Ultimate strength was greatest for the UHMWPE-suture constructs.
CONCLUSIONS AND CLINICAL RELEVANCE
Results indicated that all 4 constructs effectively stabilized MCL-deficient tarsal joints. Implants used for the TU, TN, and AU constructs had a lower profile than those used for the AN construct, which may be clinically advantageous. In vivo studies are warranted.
To assess the feasibility and accuracy of using 2 methods for reduction and alignment of simulated comminuted diaphyseal tibial fractures in conjunction with 3-D–printed patient-specific pin guides.
Paired pelvic limbs from 8 skeletally mature dogs weighing 20 to 35 kg.
CT images of both tibiae were obtained, and 3-D reconstructions of the tibiae were used to create proximal and distal patient-specific pin guides. These guides were printed and used to facilitate fracture reduction and alignment in conjunction with either a 3-D–printed reduction guide or a linear type 1A external fixator. Postreduction CT images were used to assess the accuracy of pin guide placement and the accuracy of fracture reduction and alignment.
The 3-D–printed guides were applied with acceptable ease. Guides for both groups were placed with minor but detectable deviations from the planned location (P = .01), but deviations were not significantly different between groups. Fracture reduction resulted in similar minor but detectable morphological differences from the intact tibiae (P = .01). In both groups, fracture reduction and alignment were within clinically acceptable parameters for fracture stabilization by means of minimally invasive plate osteosynthesis.
Virtual surgical planning and fabrication of patient-specific 3-D–printed pin guides have the potential to facilitate fracture reduction and alignment during use of minimally invasive plate osteosynthesis for fracture stabilization.