Failure rates and analysis of risk factors for percutaneous A1 pulley release of trigger digits

This study aimed to identify the rates and risk factors for failure of percutaneous A1 pulley release. We retrospectively analysed patients who underwent percutaneous A1 pulley release between 2015 and 2019. We defined failure as (1) pain or discomfort at the final follow-up, (2) when open release or revision percutaneous release was performed, or (3) when steroid injections were administered three or more times for symptom control. A total of 331 digits from 251 patients were included. The mean follow-up duration was 47 months (minimum 24 months). Complete resolution was achieved in 287 cases (87%), but 21% required steroid injection before symptoms settled. There was failure in 44 cases (13%). Involvement of the index, middle and ring fingers was significantly different between the successful and failure groups. Percutaneous A1 pulley release has a long-term success rate of 87%. The failure rate was higher when the procedure was performed on the index, middle or ring fingers.Level of evidence: III.

The use of medial support screw was associated with axillary nerve injury after plate fixation of proximal humeral fracture using minimal invasive deltoid-splitting approach

BACKGROUND

The purpose of this study was to evaluate the incidence and risk factors for axillary nerve injury after plate fixation of humeral fractures using minimal invasive deltoid-splitting approach. We hypothesized that the use of medial support screw (MSS) would be associated with the outcome of axillary nerve injury.

METHODS

This study retrospectively evaluated consecutive 32 patients who underwent surgical treatments for proximal or midshaft humeral fractures. Of them, we included 26 patients who were examined by electromyography/nerve conduction (EMG/NCV) study at 3-4 weeks postoperatively. We excluded 6 patients because two of them were not compliant to EMG/NCV and the remaining two died due to unrelated medical illness. Outcome assessments included pain, functional scores, range of motion, and radiographic results.

RESULTS

There were 8 male and 18 female patients with mean age of 67 ± 15 years. Mean duration of follow-up period was 31 ± 11 months. The mean time to EMG/NCS after surgery was 3.5 ± 0.6 weeks. EMG/NCS examinations revealed incomplete axillary nerve injury in 8 patients (31%) without complete nerve injury. Active forward elevation at 3 months postoperatively was significantly lower in patients with axillary nerve injury than in those without it (99° ± 12 and 123° ± 37, respectively, p = 0.047), although final clinical outcomes were not different. At surgery, MSS was used in 17 patients (65%), and 8 of them were associated with nerve injury. The use of MSS was only correlated with the outcome of axillary nerve injury, because the axillary nerve injury developed only in MSS group (p = 0.047). The MMT grade 4 in abduction strength was more common in patients with axillary nerve injury than in those without (p = 0.037).

CONCLUSIONS

Axillary nerve injury was a concern after plate fixation of proximal humeral fracture using minimal invasive deltoid-splitting approach. The use of medial support screw to improve the stability could increase a risk of axillary nerve injury when used with this approach.

Versatility of the Posterior Interosseous Artery Flap: Emphasis on Powering Up the Toe Transfer

BACKGROUND

Reverse-flow posterior interosseous artery (rPIA) flap is an excellent tool for restoration of defects in the hand and upper extremity, sparing the main arteries to the hand. Its reliability has been well established.

MATERIALS AND METHODS

Fifty-one cases of rPIA flap involving 49 patients were retrospectively reviewed. The inclusion criteria were age, sex, etiology, size and location of the defect, flap size, number of perforators included, pedicle length, flap inset, donor site coverage, complications, and ancillary procedures.

RESULTS

This study included 44 men and 5 women, ranging in age between 10 and 73 years. The subjects had soft tissue defects of the hand and upper extremity mainly due to traumatic injuries, including scar contractures of the first web space in 18 cases, thumb amputations in 6 cases, and congenital defects in 1 case. Among the 51 rPIA flap elevations, 3 cases involved flap failure due to the absence of proper pedicle. A fasciocutaneous pattern was observed in 45 cases and a myocutaneous pattern in 3 cases. In 5 cases of unplantable thumb amputations, the rPIA flap was performed for arterial inflow to the secondary toe-to-thumb transfer. Venous congestion of varying degrees was noted in 7 cases involving partial necrosis in 2 cases. During the mean 17 months of follow-up, patients were generally satisfied with the final outcomes.

CONCLUSION

The rPIA flap can be used not only for soft tissue coverage of the hand and upper extremity but also as a recipient arterial pedicle for a secondary toe-to thumb transfer.

An Increased Lateral Femoral Condyle Ratio in Addition to Increased Posterior Tibial Slope and Narrower Notch Index Is a Risk Factor for Female Anterior Cruciate Ligament Injury

PURPOSE

To investigate the relationship between the lateral femoral condyle ratio (LFCR) among osseous morphologic characteristics of the knee and anterior cruciate ligament (ACL) injury in female patients.

METHODS

Inclusion criteria were female patients (ACL group, n = 59) undergoing primary ACL reconstruction from 2012 to 2018. Control female patients (control group, n = 58) were matched by age, height, and body mass index to ACL group. They had no meniscal or ligament tear, and no trochlear dysplasia on magnetic resonance imaging. The LFCR, notch width index (NWI), and posterior tibial slope (PTS) were measured and compared between the ACL and control groups. For each risk factor, the receiver operating characteristic curve and the area under the curve and its 95% confidence interval (CI) was calculated to determine the cutoff for detecting increased risk of ACL injury.

RESULTS

The LFCR was significantly larger in the knees in the ACL group than in the control group (P = .001). The NWI was significantly smaller and the PTS was significantly larger in the knees in the ACL group than in the control group (P = .000, P = .000, respectively). The NWI (odds ratio [OR] 1.41; P = .000) was the most significant factor, followed by the PTS (OR 1.29; P = .003) and the LFCR (OR 1.26; P = .001). The area under the curve (0.67, 95% CI 0.58-0.77) for the LFCR had a sensitivity of 66% and specificity of 66% to predict an ACL injury. The cutoff of 63.9 was associated with an increased risk for ACL injury (OR 3.71; 95% CI 1.73-7.95).

CONCLUSIONS

An increased LFCR was associated with female ACL injury. The LFCR, NWI, and PTS are predictive risk factors for an ACL injury. These findings need to be considered for clinician in identifying female patients at risk for an ACL injury.

LEVEL OF EVIDENCE

III, retrospective comparative prognostic trial.

Clavicular Tunnel Complications after Coracoclavicular Reconstruction in Acute Acromioclavicular Dislocation: Coracoid Loop versus Coracoid Tunnel Fixation

Background

The purpose of this study was to compare clavicular tunnel complications after coracoclavicular (CC) reconstruction between a coracoid loop fixation group and a coracoid tunnel fixation group. We hypothesized that clavicular tunnel complications would be more common in the coracoid loop group.

Methods

This retrospective study evaluated 24 patients who underwent CC reconstruction using coracoid tunnel fixation (n = 14) and coracoid loop fixation (n = 10). Radiographic measurements included the CC distance and clavicular tunnel diameter. Clavicular tunnel complications such as tunnel widening and clavicular tunnel fractures were investigated. Clinical outcomes were assessed using the American Shoulder and Elbow Surgeons Shoulder score and the University of California at Los Angeles Shoulder score.

Results

The mean follow-up period was 17.5 months (range, 11–38 months). The final clavicular tunnel diameter and the increase in the clavicular tunnel diameter in millimeter and percentage were significantly greater in the coracoid loop group than in the coracoid tunnel group (all p < 0.05). Clavicular tunnel widening more than 100% was found in 5 patients, all belonging to the coracoid loop group. Clavicular tunnel fractures occurred in 3 patients (all in the coracoid loop group). Fracture was associated with severe tunnel widening (more than 100% increase). The mean value of the final clavicular tunnel diameter in patients with fractures was significantly larger than that in patients without (12.7 ± 3.3 mm vs. 8.4 ± 1.5 mm, p = 0.016).

Conclusions

Clavicular tunnel complications such as significant tunnel widening and fractures after CC reconstructions in acromioclavicular dislocations were common with the coracoid loop fixation technique. A greater clavicular tunnel widening and resultantly enlarged tunnel diameter might increase the risk of fracture through the clavicular tunnel.

Regeneration in Spinal Disease: Therapeutic Role of Hypoxia-Inducible Factor-1 Alpha in Regeneration of Degenerative Intervertebral Disc

The intervertebral disc (IVD) is a complex joint structure comprising three primary components—namely, nucleus pulposus (NP), annulus fibrosus (AF), and cartilaginous endplate (CEP). The IVD retrieves oxygen from the surrounding vertebral body through CEP by diffusion and likely generates ATP via anaerobic glycolysis. IVD degeneration is characterized by a cascade of cellular, compositional, structural changes. With advanced age, pronounced changes occur in the composition of the disc extracellular matrix (ECM). NP and AF cells in the IVD possess poor regenerative capacity compared with that of other tissues. Hypoxia-inducible factor (HIF) is a master transcription factor that initiates a coordinated cellular cascade in response to a low oxygen tension environment, including the regulation of numerous enzymes in response to hypoxia. HIF-1α is essential for NP development and homeostasis and is involved in various processes of IVD degeneration process, promotes ECM in NP, maintains the metabolic activities of NP, and regulates dystrophic mineralization of NP, as well as angiogenesis, autophagy, and apoptosis during IVD degeneration. HIF-1α may, therefore, represent a diagnostic tool for early IVD degeneration and a therapeutic target for inhibiting IVD degeneration

Demonstration of Confined Electron Gas and Steep-Slope Behavior in Delta-Doped GaAs-AlGaAs Core-Shell Nanowire Transistors

Strong surface and impurity scattering in III-V semiconductor-based nanowires (NW) degrade the performance of electronic devices, requiring refined concepts for controlling charge carrier conductivity. Here, we demonstrate remote Si delta (δ)-doping of radial GaAs-AlGaAs core-shell NWs that unambiguously exhibit a strongly confined electron gas with enhanced low-temperature field-effect mobilities up to 5 × 10(3) cm(2) V(-1) s(-1). The spatial separation between the high-mobility free electron gas at the NW core-shell interface and the Si dopants in the shell is directly verified by atom probe tomographic (APT) analysis, band-profile calculations, and transport characterization in advanced field-effect transistor (FET) geometries, demonstrating powerful control over the free electron gas density and conductivity. Multigated NW-FETs allow us to spatially resolve channel width- and crystal phase-dependent variations in electron gas density and mobility along single NW-FETs. Notably, dc output and transfer characteristics of these n-type depletion mode NW-FETs reveal excellent drain current saturation and record low subthreshold slopes of 70 mV/dec at on/off ratios >10(4)-10(5) at room temperature.

Biochemical, biomolecular and cellular sensing in microfluidics using flow induced admittance spectra

We present flow induced admittance spectra for electrolytes, cell culture media, different sizes of DNA solutions and neural cells using flow induced admittance spectra in a microfluidics device. The device comprises of a PDMS channel aligned with a pair of channel electrodes fabricated on glass. The peak of the flow induced admittance spectra and frequency at which the peak occurs are the key parameters used for the characterization of sensing. The response of this sensor is a function of the conductivity and dielectrivity of the effective solution. The flow induced admittances of the particles studied are corrected with their media. This sensing will be a primary component of an electrical based cytometer.