Isolated intra-articular radial head (IARH) fractures in skeletally immature patients represent a rare injury. Despite their initial benign radiologic appearance, these fractures are at risk for ...progressive radial head subluxation and may end with degenerative irreversible changes of the radiocapitellar joint. The aim of this study is to highlight the seriousness of these injuries and the importance of early diagnosis and a proper follow-up to achieve optimal outcomes.
We retrospectively reviewed 6 patients with IARH fractures treated at our institution between 2011 and 2016. All patients presented with Salter-Harris types III or IV fracture. Five of 6 fractures were initially undisplaced. Treatment, clinical, and radiographic results were analyzed. Patients were divided into 2 groups according to treatment: patients included in group A were treated conservatively, whereas patients of group B were treated with early surgery. The final functional outcome was assessed using the Oxford Elbow Score (OES). The Broberg-Morrey classification was used for the radiographic results.
Group A included 3 patients (average age, 11±2 y). They developed an initially missed posterior subluxation of the radiocapitellar joint that caused to all of them a painful elbow and limited range of motion (ROM). Despite rescue surgery, they all presented with limited ROM at the final follow-up, although no functional limitations (OES, 46.3±2.9). The radiographs showed early degenerative changes. Group B included 3 patients (average age, 11±1 y) all treated surgically within 1 week from the injury. They showed no limitation of ROM and good functional (OES, 47.7) and radiologic outcomes.
IARH fractures in skeletally immature children are deceptive injuries which are often underestimated. Surgeons should be aware of these fractures, especially when a discrepancy between the clinical signs and symptoms, and the radiologic appearance exists, as this may be the only red flag that allows their identification in the acute setting. An early and accurate diagnosis followed by prompt and more aggressive treatment when necessary is mandatory for successful results.
Level IV-case series.
Samples of Mg-3Gd (wt.%) were prepared by accumulative roll-bonding followed by annealing at different temperatures to produce samples with average grain sizes ranging from 3.3 µm to 114 µm. The ...samples were tensile tested at room temperature to characterize their strength and ductility, both of which were found to be significantly affected by transitions in mechanical behavior and deformation mechanisms. These transitions occurred with decreasing grain size and are described by: (i) a transition in the mechanical behavior from continuous flow to discontinuous flow associated with a yield point phenomenon, and (ii) a transition in the deformation mechanisms from 〈a〉 slip and twinning to 〈a〉 and 〈c + a〉 slips. The dislocation structures and deformation twins in the tensile samples have been characterized by transmission electron microscopy and electron backscatter diffraction, respectively. Dislocations of 〈a〉 and 〈c + a〉 type were identified based on two-beam diffraction contrast experiments. The results reveal that 〈a〉 dislocations and tension twins dominate in the samples with grain sizes larger than 10 µm, while 〈a〉 and 〈c + a〉 dislocations dominate in the samples with grain sizes smaller than 5 µm. In parallel, a consistent trend for both the strength and ductility to increase with decreasing grain size is observed. The appearance of a yield point phenomenon at small grain sizes has a significant effect on both strength and ductility, illustrated by an increase in boundary (Hall–Petch) strengthening and an increase in the total elongation to 36.6%. These results demonstrated a positive effect of a superposition of the transitions on both the strength and ductility of Mg-3Gd.
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Neurofibromatosis type 1 (NF-1) is an autosomal dominant genetic condition in which spinal deformities are commonly involved. However, atlantoaxial dislocation in NF-1 is extremely rare. A review of ...the English literature has identified only 10 cases in 8 reports. We report a rare case involving NF-1 associated with severe atlantoaxial dislocation.
A 22-year-old woman with NF-1 presented with progressive numbness in her left upper and lower extremities and gait difficulty for 2 months. She was treated with skull traction and partial reduction was achieved. Initial surgical strategy was posterior fusion using a screw-rod-wire construct, but significant bleeding was encountered during the surgery. To shorten the procedure time, a single sublaminar wire of the atlas was tied to the spinous process of the axis to accomplish the reduction and fixation. C1-C2 fusion was performed using iliac crest autograft. The patient had significant improvement of neurologic deficit after surgery. Due to relatively poor fixation provided by the wire, she was requested to rest in bed for the first 3 months and to wear a cervical orthosis for the next 3 months. Solid bony fusion was confirmed by radiologic examination at 18-month follow-up.
Atlantoaxial dislocation is a rare complication in NF-1 patients. Surgical reduction combined with fusion is essential for a good outcome. Spine surgeons should also be knowledgeable about the possibility of significant hemorrhage before surgery.
Purpose
Appropriate surgical management for type V complete acromioclavicular (AC) joint dislocation remains controversial. The purpose of this paper is to retrospectively report the clinical and ...radiographic outcomes of an open surgical technique consisting for AC joint ligamentous and capsular reconstruction using autologous hamstring tendon grafts and semi-permanent sutures.
Methods
Between January 2005 and December 2011, 32 consecutive patients with symptomatic type V complete AC joint dislocation underwent surgical treatment using the same technique. The median time from injury to surgery was 45 days (range 24–90). The average median postoperative clinical and radiographic follow-up time was 30 months (range 24–33). Clinical outcomes measures included the ASES score, the visual analog score (VAS), and subjective patient satisfaction score. Minimum follow-up was 2 years.
Results
ASES score increased from a median of 38.2 ± 6.2 preoperative to 92.1 ± 4.7 postoperatively (
p
≤ 0.05). The median VAS score improved from 62 mm (range 45–100 mm) preoperatively to 8 mm (range 0–20 mm) at final follow-up (
p
≤ 0.05). No patient experienced pain or discomfort with either direct palpation of the AC joint or with cross-body adduction. Final radiographs demonstrated symmetric AC joint contour in 25/32 (78%) patients. Seven patients (22%) radiographically demonstrated superior translation of the distal clavicle relative to the superior margin of the acromion but less than 50% of the clavicular width. 30/32 patients (93%) were able to return to their pre-injury level of work and sports activities.
Conclusions
This novel surgical technique using a free graft and braided suture for simultaneous coracoclavicular ligament and AC joint capsular reconstruction successfully controls superior and posterior translations after type V AC joint dislocation and minimizes the incidence of persistent postoperative AC joint subluxation.
Level of evidence
Retrospective case series, Level IV.
Unstable pelvic fracture is predominantly caused by high-energy blunt trauma and is associated with a high risk of mortality. The epidemiology in the United States is largely unknown. The purpose of ...this study was to examine the epidemiology of unstable pelvic fracture based on patient and hospital demographics in the United States during the last decade.
The Nationwide Inpatient Sample was used to identify patients who were hospitalized with unstable pelvic fracture from 2000 to 2009, using the International Classification of Diseases--9th Rev.--Clinical Modification (ICD-9-CM) codes. The primary outcome parameter consisted of analyzing the temporal trends of in-hospital admissions for unstable pelvic fracture and the associated in-hospital mortality. The data were stratified by demographic variables, including age, sex, race, and hospital region in the United States.
From 2000 to 2009, there were 24,059 patients in total; among these, 1,823 (7.6%) had open fractures, and 22,236 (92.4%) had closed fractures. The population growth-adjusted incidence was stable over time (p = 0.431). The incidence was the lowest in the northeastern region. The in-hospital mortality rate in patients with unstable pelvic fracture was 8.3% (21.3% for open fracture, 7.2% for closed fracture) and remained stable over time (p = 0.089). The in-hospital mortality rate was higher in several subgroups of patients, such as older patients, male patients, African-American patients, and patients in the northeastern region.
During the last decade, the incidence of unstable pelvic fracture has remained stable over time in the United States. The in-hospital mortality rate in patients with unstable pelvic fracture was 8.3% and remained stable over time. The rate in patients with an open fracture was approximately three times higher than that in patients with a closed fracture. The incidence was the lowest, but the in-hospital mortality rate was the highest in the northeastern region compared with the other three regions.
Epidemiologic study, level III.
The plastic response of the Senkov HfNbTaTiZr high-entropy alloy is explored by means of simulated nanoindentation tests. Both a random alloy and an alloy with chemical short-range order are ...investigated and compared to the well understood case of an elementary Ta crystal. Strong differences in the dislocation plasticity between the alloys and the elementary Ta crystal are found. The high-entropy alloys show only little relaxation of the indentation dislocation network after indenter retraction and only negligible dislocation emission into the sample interior. Short-range order-besides making the alloy both stiffer and harder-further increases the size of the plastic zone and the dislocation density there. These features are explained by the slow dislocation migration in these alloys. Also, the short-range-ordered alloy features no twinning plasticity in contrast to the random alloy, while elemental Ta exhibits twinning under high stress but detwins considerably under stress relief. The results are in good qualitative agreement with our current knowledge of plasticity in high-entropy alloys.
Sequelae of childhood elbow fracture Raux, Sébastien; Madelaine, Anya
Orthopaedics & traumatology, surgery & research,
February 2023, 2023-Feb, 2023-02-00, 20230201, Letnik:
109, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Elbow fracture is frequent in children, and often requires surgery. There are many potential sequelae: neurovascular, ligamentous and osseous. Some are liable to be overlooked, due to young age and ...the cartilaginous nature of the joint. There is little bone remodeling in the elbow and displacement fracture, and especially supracondylar or lateral condyle fracture, has to be corrected rigorously, notably in older children. In case of lateral tilt in fracture of the neck of the radial head, on the other hand, remodeling is effective. Deformity in cubitus varus and cubitus valgus leads to neurological lesions and instability. Treatment should be early, with adapted surgery in expert hands. Post-traumatic stiffness is rare. Early intensive physiotherapy is unsuited to children and could worsen the stiffness due to inflammation. Lateral condyle non-union is a classic complication of fracture. Simple percutaneous screwing is a useful option. The equivalent in the medial epicondyle is well-tolerated, and simple monitoring now suffices. Late posterolateral rotational instability is a poorly known complication. It should be considered in case of cubitus varus that becomes painful after a long asymptomatic course. Radiocapitellar subluxation is seen on X-ray. Residual radial head dislocation after primary treatment (Monteggia lesion) responds well to the Bouyala technique of ulnar flexion osteotomy associated to annular ligament repair, without requiring ligament reconstruction.
We investigated the impact of dislocations on the UV photodetection device performance. The existence of screw dislocations leads towards augmenting the dark current from the fabricated devices which ...limits the overall photocurrent generation from the device illuminated by a UV Laser source having wavelength of 325 nm. A sharp and stable transient current can be acquired from the device developed with reduced dislocation density film. Upon quantifying the performance, detection ability of the photodetectors decreases with increased dislocation density because it created leakage paths that develop trap states which enhances the possibility of recombination process of photo-generated electron-hole pairs. Thus, by restraining the screw dislocations via better growth conditions, the increment in dark current can be controlled which results in better device performance.
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•Dislocation-assisted charge-carrier transport & effective photocurrent generation.•Increment in the dark current is triggered by the existence of screw dislocations.•A direct correlation between screw dislocation density & device performance.•Results implicate persistent photoconductivity upon turning-OFF Laser source.•Fall in dislocation density will effectively enrich optoelectronic properties.
We analyze the dislocation-assisted charge carrier transport and effective photocurrent generation in the photodetection devices. Specifically, the impact of screw dislocations on the performance of GaN based metal–semiconductor-metal ultraviolet photodetector is investigated. The experiments reveal that reducing screw dislocations had a strong impact on dark current (~3x decrement) of the devices as well as on the photo-generated current (~20x enhancement) upon illumination (ultraviolet, 325 nm). The responsivity of the photodetection device has been increased from 85.05 mA/W to 130.17 mA/W with decreasing dislocation density. Because, higher dislocations created leakage paths that develop trap states which enhances the possibility of recombination process of photo-generated electron-hole pairs leading to lower charge collection. Further, the external quantum efficiency increases from 32.51% to 49.76% by reducing dislocation density. The work in this study proposes that reduction of defects/dislocations will be an effective approach to enrich the III-nitride semiconductor system for advancement in optoelectronic devices.
Background
Perilunate injuries are rare and quite often missed. We present our experience and outcomes, surgically managing these difficult injuries.
Methods
We analysed data from 14 patients who ...underwent open reduction and internal fixation of perilunate injuries. All patients underwent open reduction and fixation through the dorsal approach. Fractures were fixed with either K-wires or Headless compression screws. At regular intervals radiographs, range of motion, grip strength, modified Mayo score, Quick DASH score and Lyon wrist scores were collected.
Results
The average age of our patients was 29.2. Average time to surgical intervention was 11.3 days. The mean follow-up period was 42.3 months. modified Mayo wrist score, QuickDASH score and Lyon wrist scores were 77.86, 1.62 and 80.86, respectively. Wrist flexion/extension arc was 101.43. Wrist radial/ulnar deviation was 50.0. Mean grip strength was 69.93% of the opposite side. Radiological evidence of wrist arthritis and lunate avascular necrosis was seen in 8 (57.14%) and 4 (28.6%) cases, respectively.
Conclusion
Early open reduction of perilunate injuries gives reliable results, in spite of radiological evidence of wrist arthritis in a majority of the cases.
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