Techniques and Fixation of Olecranon Osteotomy: A Systematic Review.

Purpose: We aimed to characterize the incidence of complications regarding olecranon osteotomy, looking more specifically at the type of osteotomy and the fixation construct used to repair the osteotomy. Methods: In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a comprehensive search was performed. A study was included if it was an adult clinical study, a transverse or chevron olecranon osteotomy was performed, and the study explicitly states the fixation construct used to repair the osteotomy. A quality assessment was performed in each study prior to data extraction. Results: We included 39 studies with a total of 1,445 patients. Most studies included patients who were being treated primarily for a distal humerus fracture. The overall incidence of delayed union was 27/643 (4.2%), with a higher rate in transverse osteotomy than in chevron osteotomy (5/49 (10.2%) vs 22/595 (3.7%)). Nonunion occurred in 43/811 (5.4%) of patients, with a higher rate in transverse osteotomy (6/73 (8.2%) vs. 37/712 (5.2%)). Implant failure or loss of reduction occurred in 44/746 (5.9%) of patients, with a higher rate in transverse osteotomy (11/49 (22.4%) vs 33/688 (4.8%)). The removal of implants occurred in 236/1078 (21.9%) of all patients, with the highest rate in those studies that used plate fixation 44/99 (44.4%). Conclusions: Compared with chevron osteotomy, patients who underwent transverse osteotomy had a higher incidence of delayed union, nonunion, and implant failure or loss of reduction requiring revision surgery. The incidence of implant removal indicates that patients should be informed that nearly half of the osteotomy fixed with a plate was removed after implantation. Type of study/level of evidence: Therapeutic III.

Test-Retest Reliability of Microlinguistic Information Derived From Spoken Discourse in Persons With Chronic Aphasia.

PURPOSE: The purpose of this study was to characterize test-retest reliability of discourse measures across a battery of common tasks in individuals with aphasia and prospectively matched adults without brain damage. METHOD: We collected spoken discourse during five monologue tasks at two timepoints (test and retest; within 2 weeks apart) in an aphasia group (n = 23) and a peer group with no brain damage (n = 24). We evaluated test-retest reliability for percentage of correct information units, correct information units per minute, mean length of utterance, verbs per utterance, noun/verb ratio, open/closed class word ratio, tokens, sample duration (seconds), propositional idea density, type-token ratio, and words per minute. We explored reliability's relationship with sample length and aphasia severity. RESULTS: Rater reliability was excellent. Across tasks, both groups demonstrated discourse measures with poor, moderate, and good reliability, with the aphasia group having measures demonstrating excellent test-retest reliability. When evaluating measures within each task, test-retest reliability again ranged from poor to excellent for both groups. Across groups and task, measures that appeared most reliable appeared to reflect lexical, informativeness, or fluency information. Sample length and aphasia severity impacted reliability, and this differed across and by task. CONCLUSIONS: We identified several discourse measures that were reliable across and within tasks. Test-retest statistics are intimately linked to the specific sample, emphasizing the importance of multiple baseline studies. Task itself should be considered an important variable, and it should not be assumed that discourse measures found to be reliable across several tasks (averaged) are likewise reliable for a single task. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.23298032.

Bone Morphogenetic Protein-2 Rapidly Heals Two Distinct Critical Sized Segmental Diaphyseal Bone Defects in a Porcine Model.

INTRODUCTION: Segmental bone defects (SBDs) are devastating injuries sustained by warfighters and are difficult to heal. Preclinical models that accurately simulate human conditions are necessary to investigate therapies to treat SBDs. We have developed two novel porcine SBD models that take advantage of similarities in bone healing and immunologic response to injury between pigs and humans. The purpose of this study was to investigate the efficacy of Bone Morphogenetic Protein-2 (BMP-2) to heal a critical sized defect (CSD) in two novel porcine SBD models. MATERIALS AND METHODS: Two CSDs were performed in Yucatan Minipigs including a 25.0-mm SBD treated with intramedullary nailing (IMN) and a 40.0-mm SBD treated with dual plating (ORIF). In control animals, the defect was filled with a custom spacer and a bovine collagen sponge impregnated with saline (IMN25 Cont, n = 8; ORIF40 Cont, n = 4). In experimental animals, the SBD was filled with a custom spacer and a bovine collage sponge impregnated with human recombinant BMP-2 (IMN25 BMP, n = 8; ORIF40 BMP, n = 4). Healing was quantified using monthly modified Radiographic Union Score for Tibia Fractures (mRUST) scores, postmortem CT scanning, and torsion testing. RESULTS: BMP-2 restored bone healing in all eight IMN25 BMP specimens and three of four ORIF40 BMP specimens. None of the IMN25 Cont or ORIF40 Cont specimens healed. mRUST scores at the time of sacrifice increased from 9.2 (±2.4) in IMN25 Cont to 15.1 (±1.0) in IMN25 BMP specimens (P < .0001). mRUST scores increased from 8.2 (±1.1) in ORIF40 Cont to 14.3 (±1.0) in ORIF40 BMP specimens (P < .01). CT scans confirmed all BMP-2 specimens had healed and none of the control specimens had healed in both IMN and ORIF groups. BMP-2 restored 114% and 93% of intact torsional stiffness in IMN25 BMP and ORIF40 BMP specimens. CONCLUSIONS: We have developed two porcine CSD models, including fixation with IMN and with dual-plate fixation. Porcine models are particularly relevant for SBD research as the porcine immunologic response to injury closely mimics the human response. BMP-2 restored healing in both CSD models, and the effects were evident within the first month after injury. These findings support the use of both porcine CSD models to investigate new therapies to heal SBDs.

Internal Fixation Construct and Defect Size Affect Healing of a Translational Porcine Diaphyseal Tibial Segmental Bone Defect.

BACKGROUND AND OBJECTIVE: Porcine translational models have become the gold-standard translational tool to study the effects of major injury and hemorrhagic shock because of their similarity to the human immunologic response to trauma. Segmental bone defects (SBDs) typically occur in warfighters with associated severe limb trauma. The purpose of this study was to develop a translational porcine diaphyseal SBD model in Yucatan minipigs (YMPs), which could be used in bone healing investigations that simulate injury-relevant conditions. We were specifically working toward developing a critical sized defect (CSD). METHODS: We used an adaptive experimental design in which both 25.0 mm and 40.0 mm SBDs were created in the tibial mid-diaphysis in skeletally mature YMPs. Initially, eight YMPs were subjected to a 25.0 mm SBD and treated with intramedullary nailing (intramedullary nail [IMN] 25mm). Due to unanticipated wound problems, we subsequently treated four specimens with identical 25.0 mm defect with dual plating (open reduction with internal fixation [ORIF] 25mm). Finally, a third group of four YMPs with 40.0 mm defects were treated with dual plating (ORIF 40mm). Monthly radiographs were made until sacrifice. Modified Radiographic Union Score for Tibia fractures (mRUST) measurements were made by three trauma-trained orthopedic surgeons. CT scans of the tibias were used to verify the union results. RESULTS: At 4 months post-surgery, mean mRUST scores were 11.7 (SD ± 1.8) in the ORIF 25mm YMPs vs. 8.5 (SD ± 1.4) in the IMN 25mm YMPs (P < .0001). All four ORIF 25mm YMPs were clinically healed. In contrast, none of the IMN 25mm YMPs were clinically healed and seven of eight IMN 25mm YMPs developed delayed wound breakdown. All four of the ORIF 40mm YMPs had flail nonunions with complete hardware failure by 3 months after surgery and were sacrificed early. CT scanning confirmed that none of the IMN 25mm YMPs, none of the ORIF 40mm YMPs, and two of four ORIF 25mm YMPs were healed. A third ORIF 25mm specimen was nearly healed on CT scanning. Inter-rater and intra-rater reliability interclass coefficients using the mRUST scale were 0.81 and 0.80, respectively. CONCLUSIONS: YMPs that had a 40 mm segment of bone removed from their tibia and were treated with dual plating did not heal and could be used to investigate interventions that accelerate bone healing. In contrast, a 25 mm SBD treated with dual plating demonstrated delayed but successful healing, indicating it can potentially be used to investigate bone healing adjuncts or conversely how concomitant injuries may impair bone healing. Pigs treated with IMN failed to heal and developed consistent delayed wound breakdown presumably secondary to chronic limb instability. The porcine YMP SBD model has the potential to be an effective translational tool to investigate bone healing under physiologically relevant injury conditions.

A Biomechanical Comparison of Modified Radioscapholunate Fusion Constructs for Radiocarpal Arthritis.

PURPOSE: This biomechanical study compared fixation constructs used in radioscapholunate (RSL) arthrodesis. We hypothesized that plates and screws, pin plate, and headless screws would all provide similarly stable fixation constructs. METHODS: We chose 27 fresh-frozen cadaveric extremities, 14 of which were matched pairs and randomized them into 3 groups to match age, body mass index, and sex. An RSL arthrodesis was simulated with plates and screws, pin plates, or headless compression screws via a standard dorsal approach to the wrist. Specimens were mounted into a custom jig and cycled through an arc of 120° for 5,000 cycles to simulate 6 weeks range of motion (ROM). A 9-mm stroke differential variable reluctance transducer recorded continuous displacement, and gross hardware failure in the form of screw or pin cutout was investigated after the simulation. RESULTS: Greater distraction across the RSL articulation was observed in the headless screws compared with the plate-and-screws and pin-plate constructs, with no difference between the plates and screws and pin plates. Greater average displacement was observed in the headless screws compared with the plate-and-screws and pin-plate constructs, with no difference between the pin plates and plates and screws. Gross hardware failure was observed least in plates and screws followed by pin plates. CONCLUSIONS: Plate-and-screw and pin-plate constructs are biomechanically superior in resisting RSL distraction compared with headless compression screws for RSL arthrodesis over 6 weeks of simulated ROM in the absence of healing. CLINICAL RELEVANCE: The results of this study demonstrated negligible arthrodesis site distraction in the plate-and-screws and pin-plate constructs when 6 weeks of ROM was simulated. When translated to a clinical scenario, these findings may allow earlier discontinuation of external immobilization after surgery.

Reduction of serum 25-hydroxyvitamin D concentrations with intravenous lipid emulsion in a dog.

The recommended daily allowance of vitamin D has been increased. Toxicosis in pets may increase as a result. A dog ingested ~ 200 000 IU of vitamin D, serum concentrations were above the reference range (RR) and decreased to the RR after lipid treatment. This is the first known report of lipid treatment for hypervitaminosis D.

Réduction des concentrations sériques de 25-hydroxyvitamine D à l'aide d'une émulsion intraveineuse de lipides chez un chien. L'apport quotidien recommandé de vitamine D a été accru. La toxicose chez les animaux de compagnie peut augmenter en raison de cette hausse. Un chien a ingéré ~ 200 000 UI de vitamine D, les concentrations sériques étaient supérieures à la fourchette de référence (FR) et a chuté à la FR après le traitement aux lipides. Il s'agit du premier rapport connu de traitement aux lipides pour la toxicose à l'hypervitaminose D.(Traduit par Isabelle Vallières).

The use of a sliding bone graft in the upper extremity for long bone nonunions.

Nonunions of the upper extremity are a source of significant morbidity and can be difficult to treat. This paper describes a sliding bone graft technique that offers several significant advantages over other techniques for nonunions.

Prion sequence polymorphisms and chronic wasting disease resistance in Illinois white-tailed deer (Odocoileus virginianus).

Nucleic acid sequences of the prion gene (PRNP) were examined and genotypes compiled for 76 white-tailed deer from northern Illinois, which previously tested positive for chronic wasting disease (CWD), and 120 negative animals selected to control for geographic location and age. Nine nucleotide polymorphisms, seven silent and two coding, were found in the sampled population. All observed polymorphisms except two of very low frequency were observed in both negative and positive animals, although five polymorphic loci had significantly different distributions of alleles between infected and non-infected individuals. Nucleotide base changes 60C/T, 285A/C, 286G/A and 555C/T were observed with higher than expected frequencies in CWD negative animals suggesting disease resistance, while 153C/T was observed more than expected in positive animals, suggesting susceptibility. The two coding polymorphisms, 285A/C (Q95H) and 286G/A (G96S), have been described in white-tailed deer populations sampled in Colorado and Wisconsin. Frequency distributions of coding polymorphisms in Wisconsin and Illinois deer populations were different, an unexpected result considering the sampled areas are less than 150 km apart. The total number of polymorphisms per animal, silent or coding, was negatively correlated to disease status. The potential importance of silent polymorphisms (60C/T, 153C/T, 555C/T), either individually or cumulatively, in CWD disease status has not been previously reported.