Ch. 56: Pelvis Flashcards
Rollins VCOT 2019 PQ
Evaluation of fluoroscopic-guided closed reduction versus open reduction of SI fracture-luxations stabilized with a lag screw
Optimal screw depth to sacral body width? Achieved in which group more?
Lower lag screw loosening with which?
General overall comp amount? Different bw groups?
FGCR that required conversion?
Optimal screw depth to sacral body width ratio (>60%) was achieved in a significantly higher proportion of FGCR cases than openly reduced
A significantly lower rate of lag screw loosening was found in FGCR cases
Few peri-and postoperative complications were noted across both groups
4/17 FGCR cases requiring conversion to an open approach were excluded from data analysis; they had a longer duration from trauma to sx repair than median duration from trauma to surgical repair for cases successfully reduced in closed fashion
Naiman VSURG 2021
Radiation exposure associated with percutaneous fluoroscopically guided lag screw fixation for sacroiliac luxation in dogs
Technique they did?
Cumulative radiation doses?
dogs with 100% sacral screw purchase?
Cadavers with iatrogenic SIL underwent reduction and stabilization with 3.5-mm screws. Hypodermic needles (14 gauge) and fluoroscopy were used to orient two Kirschner wires for temporary stabilization and to guide drilling of glide and pilot holes using cannulated drill bits.
Cumulative radiation doses of 0.4 mrem for the dominant arm of the assistant and 0 mrem for the primary surgeon
16/17 dogs had 100% sacral screw purchase, with the remaining case achieving 93.4% purchase.
– technique had repeatable accurate screw placement with low levels radiation
McCarthy VSURG 2022
Accuracy of a drilling with a custom 3D printed guide or free-hand technique in canine experimental sacroiliac luxations
Mean measured angles differed how bw groups?
% of sacral corridor disruption in each?
Free-hand drilling technique (FHDT) compared to 3D-printed patient-specific drill guide (3D-GDT)
Mean craniocaudal and dorsoventral angles for both CT- and 3D-measured 3D-GDT were lower compared to FHDT
Entry dorsoventral and end craniocaudal, dorsoventral, and 3D linear deviations were reduced with 3D-GDT.
Sacral corridor disruption was present in 20% (3/15) for FHDT compared with 0% for 3D-GDT.
CT and 3D analyses were in strong agreement
Wills VCOT 2022
Computed tomographic evaluation of the accuracy of minimally invasive sacroiliac screw fixation in cats
Screw sizes used and diameter proportion of sacrum?
Reduction % and sacral purchase % in 3/5 cases?
Mean DV and CrCd screw angulations?
What 2 incidental follow up comps did they find?
(they retrospectively included cats then did prospective CT follow ups)
2.7mm, 2.4 mm ; Mean screw size as a proportion of diameter of sacrum 47.7%
Reduction >90% in the craniocaudal plane and sacral purchase >60% in ⅗ cats
mean dorsoventral screw angulation 1.6 degrees
craniocaudal angulation was -4.5 degrees
screw loosening in 1 case of bilateral repair
Penetration of neural canal in one case
- this had not been detected with postoperative radiographic evaluation
Lembersky VRU 2022
Repeatability and accuracy of a novel, quantitative radiographic method for differentiating normal canine sacroiliac joints from joints with subluxation or luxation: pilot study
What / how did they measure?
Normal pelvis angles for these measurements? Abnormal pelvis?
Reliability among their 3 readers?
Cut off angle established?
measuring the angle between a line connecting the iliac wings and parallel lines across three anatomical landmarks (cranial endplate of L7, caudal endplate of L6, cranial endplate of L6) on a single ventrodorsal radiograph.
The angles for the normal pelves ranged from 0.6◦ to 1.5◦, while abnormal angles ranged from 3.8◦ to 7.1◦points
There was excellent reliability among the three readers with an intraclass correlation (ICC) value of 0.90 and an excellent agreement between day 0 and day 30 readings with an ICC value of 0.91.
cut-off angle of 2.0◦, using the line parallel to the cranial endplate of L6, provided overall the best accuracy, sensitivity, and specificity to differentiate normal versus abnormal pelves
Bird JFMS 2020
Conservative management of sacroiliac luxation fracture in cats: medium- to long-term functional outcome
How many cats had excellent outcome? Good?
Conclusion?
conservative management of SILF in cats with no other concurrent fractures of the pelvic weightbearing axis
Mean displacement 20%
Mean sacral index 0.935
12/13 cats had excellent outcome with no difficulty performing normal activities
1/13 had good outcome, with slight or occasional difficulty performing normal activities
provides evidence to support the current guidelines of conservative management of SILF. The inherent bias of case selection in our population implies that this treatment cannot be recommended for all cases of SILF
Han JFMS 2022
Evaluation of a screw insertion landmark for a minimally invasive repair technique in induced bilateral sacroiliac luxation in feline cadavers
How did they determine landmark?
Joint reduction %? different in pelvic canal diameter?
The screw insertion point was determined using the caudal iliac crest and cranial acetabular rim. These two points make the first guideline; a second guideline ran perpendicular to the caudal iliac crest point. The screw insertion point was halfway along the second guideline across the ilium body. Surgery was performed in a minimally invasive manner using fluoroscopy.
the sacroiliac joint reduction percentage was almost 90% and there was no significant difference in pelvic canal diameter ratio before and after surgery.
Screw depth/sacral width was >60% in all cadavers.
the angle between the screw and sacrum wing was within the normal range of 96.24° to the left and 98.65° to the right, except in one case.
Hanlon VSURG 2022
Mechanical evaluation of canine sacroiliac joint stabilization using two short screws
what screw type/combo did they look at (3)? Spanning what distance?
Difference in peak load, yield load, and stiffness?
Mechanical differences?
cadaveric
single long lag screw (LLS) (spanning 60%), 2 short lag screws (SLS), or 2 short positional screws (SPS) - short 3.5 mm cortical screws, each spanning an average of 23% of the width of the sacral body.
Peak load, yield load, and stiffness were more than 2 times greater in both the SLS and SPS groups when compared with the LLS group
No mechanical difference was identified between the short-screw groups
No mechanical advantage between short screws inserted in positional vs. lag fashion
Wise VRU 2022
The prevalence of sacroiliac joint CT and MRI findings is high in large breed dogs
2 categories of findings with highest prevalence?
Associations w pt age, sex, BW? Concurrent LS disease?
53 large breed dogs (LBDs; >22.7kg) w/ sacroiliac joint (SIJ) disease
20 CT, 33 MRI
Categories of findings with the highest prevalence were:
Subchondral erosion (100% CT, 100% MRI)
Subchondral sclerosis (95% CT, 97% MRI)
The total # of SIJ findings per dog were not associated w/ dog age, sex, BW, or concurrent LS or pelvic region findings.
The total # of MRI SIJ findings per dog differed btwn German Shepherds & Labrador Retrievers (P = 0.0237) as well as btwn Labrador Retrievers & other breeds (P = 0.0414).
These results indicated that CT & MRI findings reported in humans w/ SIJ disease are common in large breed dogs.
Hammer VSURG 2020
Predictors of comorbidities and mortality in cats with pelvic fractures
How many % involved weight bearing axis or not?
Sacral fx in %?
Rates of sx and mortality increased with what?
Survival to dc?
What associated with non survival?
280 cats with no (9%), unilateral (43%), and bilateral (48%) involvement of weight-bearing axis
Sacral fractures were found in 12 % of cats
Surgical treatment and mortality rates increased progressively with severity of the pelvic fractures
20% did not survive to discharge
Cats with neuro injuries more likely to not survive
Petrovsky VSURG 2021
Short-term outcomes in 59 dogs treated for ilial body fractures with locking or non-locking plates
Implant failure %? NLS vs LPS?
Higher probability of failure with what?
Most common failure type?
Implant failure occurred in 18/63 hemipelves (29%)
17 NLS (non locking plate) implants and 1 LPS (locking plate)
multivariate logistic regression revealed a significantly (19.5 times) higher probability of implant failure if NLS were used as the fixation method
Screw loosening was the most common implant failure encountered
Piana VCOT 2020
Locking plate fixation for canine acetabular fractures
Locking implants used?
Sole method of fixation in #?
complications? minor vs major?
Return to function?
Locking implants were VetLOX (4/18), string-of-pearls (7/18) and locking compression plates (7/18).
Locking plates and screws were used as the sole method of fixation in 10/18 acetabula, and as adjunctive fixation in 8/18.
2 minor complications (loose screws) and 1 catastrophic complication
16/17 (94%) dogs returned to function with radiographic documentation of fracture healing.
LT outcome positive in most cases (LOAD questionnaire)
Complication rate was comparable to historic reports using non-locking implants.
Paulick VSURG 2022
Ex vivo comparison of lateral plate repairs of experimental oblique ilial fractures in cats
What implants looked at?
Which endured higher loads before failure?
Which are less resistant to cyclic loading?
Failure in NL how?
Figure in LS how?
Advanced Locking Plate System (ALPS-5); (2) the Advanced Locking Plate System (ALPS-6.5); (3) the Locking Compression Plate 2.0 (LCP); (4) the FIXIN 1.9-2.5 Series (FIXIN), and (5) the Dynamic Compression Plate 2.0 (DCP)
ALPS 6.5, FIXIN, and LCP endured higher loads before failure than the DCP
DCP and ALPS-5 constructs are less resistant to cyclic loading.
Failure in nonlocking specimens involved screw loosening.
Failure involved bone slicing in locking specimens.
Wiersema VCOT 2021
Comparison of single versus double lateral plating in treatment of feline ilial fractures using veterinary cuttable plates
Implant failure MC with what group?
Sacral index diff?
Conclusion?
Implant failure occurred more often in SLP vs DLP (14/29 vs 6/48)
Sacral index follow-up was different between the groups (1 SLP vs 0.98 DLP)
Median change was -0.04 in SLP and 0 in DLP
DLP leads to significantly less implant failure and significantly less pelvic canal narrowing compared with SLP.
Bourbos VCOT 2021
The use of intraoperative skeletal traction for the repair of pelvic fractures: an experimental cadaveric study
Traction and distraction possible? How many cm?
Peal force for transverse? Oblique fx?
Correlations between what and force?
Increasing amounts of traction were applied to each fracture and recorded until a distraction length of 2 cm was created between the bone fragments.
Measurement of traction and distraction possible in all fractures
2 cm distraction
Peak traction force 15.4 kg for transverse and 18.6 kg for oblique
Strong correlations (R=0.8 for transverse, and 0.93 for oblique) between body weight and the force required to obtain a destruction length
