Development of a Ratiometric Fluorescent Cu(II) Indicator Based on Poly(N-isopropylacrylamide) Thermal Phase Transition and an Aminopyridyl Cu(II) Ligand.

An aqueous Cu2+ and Zn2+ indicator is reported based on copolymerizing aminopyridine ligands and the environment-sensitive dansyl fluorophore into the responsive polymer poly(N-isopropylacrylamide) (PNIPAm). The metal ion binding creates charge and solvation that triggers PNIPAm's thermal phase transition from hydrophobic globule to hydrophilic open coil. As a basis for sensing the metal-binding, the dansyl fluorescence emission spectra provide a signal at ca. 530 nm and a signal at 500 nm for the hydrophobic and hydrophilic environment, respectively, that are ratiometrically interpreted. The synthesis of the title pyridylethyl-pyridylmethyl-amine ligand (acronym PEPMA) with a 3-carbon linker to the copolymerizable group, aminopropylacrylamide (PEPMA-C3-acrylamide), is reported, along with a nonpolymerizable model ligand derivative. The response of the polymer is validated by increasing temperature from 25 °C to 49 °C, which causes a shift in maximum emission wavelength from 536 nm to 505 nm, along with an increase in the ratio of emission intensity of 505 nm/536 nm from 0.77 to 1.22 (λex = 330 nm) as the polymer releases water. The addition of divalent Cu or Zn to the indicator resulted in a dansyl emission shift of 10 nm to a longer wavelength, accompanied by fluorescence quenching in the case of Cu2+. The addition of EDTA to the Cu2+-loaded indicator reversed the fluorescence shift at 25 °C to 35 °C. The affinities of Cu2+ and Zn2+ for the PEPMA derivatives are log Kf = 11.85 and log Kf = 5.67, respectively, as determined by potentiometric titration. The single-crystal X-ray structure of the Cu2+-PEPMA derivative is five-coordinate, of-geometry intermediate between square-pyramidal and trigonal-bipyramidal, and is comparable to that of Cu2+ complexes with similar formation constants.

Visualizing genomic data: The mixing perspective.

We report on a novel way to visualize genomic data. By considering genome coding sequences, cds, as sets of the N=61 non-stop codons, one obtains a partition of the total number of codons in each cds. Partitions exhibit a statistical property known as mixing character which characterizes how mixed the partition is. Mixing characters have been shown mathematically to exhibit a partial order known as majorization (Ruch, 1975). In previous work (Seitz and Kirwan, 2022) we developed an approach that combined mixing and entropy that is visualized as a scatter plot. If we consider all 1,121,505 partitions of 61 codons, this produces a plot we call the theoretical mixing space, TGMS. A normalization procedure is developed here and applied to real genomic data to produce the genome mixing signature, GMS. Example GMS's of 19 species, including Homo sapiens, are shown and discussed.

Surgical Technique and Outcomes of Reconstruction for Blauth Type III Thumb Hypoplasia.

BACKGROUND: Historically, amputation and pollicization has been the recommended surgical treatment for Blauth type III hypoplastic thumbs. However, due to aesthetic objections or cultural preferences, some parents seek out alternative surgical options. The present study describes a nontraditional technique that preserves and augments the hypoplastic thumb. METHODS: Patient charts were retrospectively reviewed to identify patients with Blauth type III hypoplastic thumbs who underwent thumb reconstruction at our institution from 2008 to 2018. The reconstruction procedure involved toe phalanx transfer, staged tendon transfers, and lengthening as needed. Motion was assessed categorically as ability to flex, extend, or oppose the thumb. Functionality was assessed as ability to pinch and grasp with the surgical hand. Patient- or parent-reported improvement in thumb function was also recorded. RESULTS: Of the 13 patients, 100% could flex, extend, and oppose the thumb to some degree. Eleven patients (85%) had functional one-handed grasp, and 9 (69%) had a functional pinch. Eleven patients (85%) reported no functional limitations of the operative hand. Thirteen patients (100%) reported improvement in hand function after surgery as compared to pre-operatively. There were 2 minor complications (15%), both of which resolved after intervention. No patients experienced donor-site morbidity. CONCLUSIONS: Reconstruction of Blauth III thumbs is a nontraditional technique that allows for digit retention by salvaging the hypoplastic thumb. In the present study, the majority of patients had functional thumbs and all reported postoperative improvement. Overall, our results suggest that reconstruction is a viable surgical option for Blauth III hypoplastic thumbs.

Concomitant Total Shoulder Arthroplasty and Ipsilateral Carpal Tunnel Release: Is It Safe?

PURPOSE: Symptomatic carpal tunnel syndrome in patients with advanced ipsilateral glenohumeral arthritis requiring total shoulder arthroplasty (TSA) may be easily overlooked. Even when diagnosed beforehand, most upper extremity surgeons have historically chosen to perform TSA and carpal tunnel release (CTR) separately. We hypothesized that combined single-stage TSA and CTR is feasible and yields results comparable with those when the 2 procedures are performed separately, while avoiding 2 surgeries. METHODS: This was a retrospective review of patients who underwent single-stage primary TSA and ipsilateral CTR between 2015 and 2019. The shoulder outcomes included pain, range of motion, and validated quality of life (QoL) questionnaires: Veterans RAND 12-Item Health Survey (VR-12) and Penn Shoulder Score. The CTR outcomes included pain, grip, pinch, VR-12, shortened Disabilities of the Arm, Shoulder, and Hand Questionnaire (QuickDASH), and Boston Carpal Tunnel Questionnaire. The time to the initiation of rehabilitation and complications were also analyzed. The comparison group consisted of patients who underwent independent TSA or CTR during the same period. RESULTS: Forty-one patients underwent concomitant TSA and CTR, 248 underwent isolated TSA, and 154 underwent isolated CTR. The shoulder outcomes of patients who underwent the combined procedure were similar to those of patients who underwent isolated TSA in terms of pain, range of motion, general QoL (VR-12), and shoulder-specific QoL (Penn Shoulder Score). The outcomes of patients who underwent the combined procedure were similar to those of patients who underwent isolated CTR in terms of pain, grip and pinch, general QoL (VR-12), QuickDASH, and Boston Carpal Tunnel Questionnaire. The time to the initiation of rehabilitation was also comparable. CONCLUSIONS: Concomitant CTR and TSA are feasible. The functional outcomes and QoL of patients who underwent the concomitant treatment were comparable with those of patients who underwent the 2 procedures separately. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Prevalence of Orthopedic Manifestations in Patients With Cardiac Amyloidosis With a Focus on Shoulder Pathologies.

Transthyretin cardiac amyloidosis (ATTR-CA) is a restrictive cardiomyopathy that has been associated with multiple orthopedic pathologies years before it manifests in the heart. There have been no studies on the prevalence of a wide range of shoulder pathologies in patients with cardiac amyloidosis (CA). Due to the preferential deposition of transthyretin in the soft tissues and joints, we predicted a greater prevalence of shoulder pathologies and other orthopedic manifestations in patients with ATTR-CA. This single-center, retrospective, case-control study, analyzed 1,310 patients with CA, 830 with ATTR-CA, and 480 with light-chain CA (AL-CA) from a dedicated CA REDcap database. Odds ratios comparing patients with CA to the age-matched published estimate of over 300 million patients in the general population were determined for shoulder, hip, and knee arthroplasty. Years between a patient's first shoulder pathology (i.e., shoulder arthroplasty) and the year of their diagnosis with CA were determined using data from patients with a known date of surgery. Overall, patients with ATTR-CA compared with patients with AL-CA presented more frequently with shoulder pathologies (p <0.001) and at least 1 orthopedic manifestation (p <0.001). The odds of patients with ATTR-CA and AL-CA aged 60 years or older who underwent shoulder arthroplasty was 6.05 times greater (95% confidence interval 4.26 to 8.60) and 1.63 times greater (95% confidence interval 0.67 to 3.94), respectively, compared with age-matched controls. Shoulder pathologies and concomitant orthopedic pathologies are common in patients with ATTR-CA and may help identify patients with CA earlier in their disease progression for earlier intervention and treatment.

A preliminary study of radioulnar wrist compression in improving patient-reported outcomes of carpal tunnel syndrome.

Previous studies have shown radioulnar wrist compression augments carpal arch space. This study investigated the effects of radioulnar wrist compression on patient-reported outcomes associated with carpal tunnel syndrome. Subjects underwent thrice-daily (15 min each time 45 min daily) wrist compression over 4 weeks with an additional four weeks of follow-up without treatment. Primary outcomes included Boston Carpal Tunnel Questionnaire symptom and functional severity scales (SSS and FSS) and symptoms of numbness/tingling based on Visual Analog Scales. Our results showed that radioulnar wrist compression improved SSS by 0.55 points after 2 weeks (p < 0.001) and 0.51 points at 4 weeks (p < 0.006) compared to the baseline scale. At the four-week follow-up, SSS remined improved at 0.47 points (p < 0.05). Symptoms of numbness/tingling improved at two and 4 weeks, as well as the follow-up (p < 0.05). Hand motor impairment such as weakness had a lower frequency across carpal tunnel syndrome sufferers and does not significantly improve (p > 0.05). Radioulnar wrist compression might be an effective alternative treatment in improving sensory related symptoms in patients with mild to moderate carpal tunnel syndrome.

The Van Gorder approach for total elbow arthroplasty.

BACKGROUND: Surgical management of the triceps during exposure for total elbow arthroplasty (TEA) is critical to a successful outcome. Previously described techniques include elevating the triceps insertion from one side or leaving the triceps insertion attached and dislocating the joint. Another approach to the elbow, first described in 1933 by Willis Campbell, MD, and subsequently modified by George Van Gorder, MD, involves turning down the triceps tendon without disrupting the triceps insertion. This approach offers complete visualization of the joint and provides excellent exposure for TEA. Only the original report of the technique and a small series of patients using this technique for TEA exist in the literature. The goal of this study was to evaluate outcomes of the Van Gorder approach in a large series of patients undergoing TEA. METHODS: All patients who underwent TEA from 2008 to 2016 were retrospectively reviewed. Only patients who underwent primary TEA performed through the Van Gorder approach with at least 6 months' follow-up were included for analysis. Patients with prior elbow surgery were excluded. Demographic data, indication for surgery, postoperative range of motion, triceps function, and need for additional surgery were recorded. Prospectively collected visual analog scale (VAS) and Global Health Quality of Life scores were also analyzed. RESULTS: A total of 53 patients met inclusion criteria. The mean age was 62 years, 81% were female, and the average follow-up was 30.2 months. The most common surgical indications included inflammatory arthritis (47%), osteoarthritis (24%), and fracture (19%). Postoperatively, average elbow arc of motion was an 8°-137°. There was 1 patient (1.89%) who developed failure of their triceps extension mechanism. A total of 10 patients (19%) underwent additional elbow surgery most commonly for superficial wound complications. Preoperative VAS scores decreased significantly, starting at 3 months postoperatively (6.76 to 3.37, P < .001), and remained constant at the 12- and 24-month postoperative visits. CONCLUSIONS: This is the largest study evaluating the Van Gorder surgical approach to the elbow for primary TEA with an average follow-up of 32 months. Overall rates of triceps failure and reoperation are consistent with other approaches for TEA.

Combined Treatment of Trapeziometacarpal Joint Arthritis and Scapholunate Advanced Collapse Wrist.

PURPOSE: The combined treatment of trapeziometacarpal joint arthritis and scapholunate advanced collapse (SLAC) wrist presents unique challenges. The consequences of the loss of radial column support caused by scaphoidectomy and trapeziectomy are not well known. The purpose of this study was to evaluate the outcomes of the simultaneous and staged treatment of trapeziometacarpal joint arthritis and SLAC wrist. METHODS: A retrospective review of patients who underwent surgery for both trapeziometacarpal joint arthritis and SLAC wrist was performed. The wrist and thumb range of motion; grip and pinch strength; pain; quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores; and radiographs were analyzed. RESULTS: Twenty-four patients who underwent both trapeziectomy and 1 of 3 procedures for SLAC wrist (4-corner fusion [n = 10]), proximal row carpectomy [n = 9], and total wrist arthroplasty [n = 5]) in a single stage (n = 10) or in 2 stages (n = 14) were included. The median age was 63 years. The median follow-up period was 35 months. Twelve (50%) patients underwent complete scaphoidectomy, and 12 (50%) patients underwent partial scaphoidectomy. All 3 procedures resulted in an improvement in pain at rest, pain during activity, and quick Disabilities of the Arm, Shoulder and Hand scores. The final range of motion, grip and pinch strength, and complication rates were consistent with those reported in the literature for isolated procedures. CONCLUSIONS: Trapeziometacarpal joint arthritis and SLAC wrist may be treated either simultaneously or in stages. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Ulnar Extension Coupling in Functional Wrist Kinematics During Hand Activities of Daily Living.

PURPOSE: Wrist circumduction is increasingly used as a functional motion assessment for patients. Thus, increasing our understanding of its relation to the functional motion envelope is valuable. Previous studies have shown that the wrist is preferentially extended during hand activities of daily living (ADLs), with greater ulnar than radial deviation. The purpose of this study was to characterize the functional wrist motions of 22 modern ADLs in healthy subjects. We hypothesized that the subjects would perform ADLs predominantly in ulnar extension. METHODS: Ten right-handed, healthy subjects performed flexion-extension, radioulnar deviation, maximal circumduction, and 22 modern ADLs. Angular wrist positions were obtained by tracking retroreflective markers on the hand and forearm. Angular motion data were analyzed with a custom program for peak/trough angles in flexion extension and radioulnar deviation, ellipse area of circumduction data, and ellipse area of combined motion data. RESULTS: The required ranges of motion for ADLs were from 46.6° ± 16.5° of flexion (stirring task) to 63.8° ± 14.2° of extension (combing) in flexion-extension and from 15.6° ± 8.9° of radial deviation (opening a jar) to 32.5° ± 8.3° of ulnar deviation (picking up smartphone) in radioulnar deviation. Ellipse area of combined motion data of the 22 ADLs were, on average, 58.2% ± 14.3% of the ellipse area of maximal circumduction. A motion data quadrantal analysis revealed that 54.9% of all ADL wrist motion occurred in ulnar extension. Among the average wrist positions for 22 ADLs, 16 were located in the ulnar extension quadrant. CONCLUSIONS: This study revealed a functional wrist motion envelope that was less than 60% of wrist maximal motion capacity on average. Our results also showed that the majority of ADLs are performed in ulnar extension of the wrist. CLINICAL RELEVANCE: Baseline values for healthy subjects performing 22 wrist ADLs can inform future studies assessing dysfunction, postsurgical changes, and rehabilitation progress.

Cardiac Amyloidosis Screening at Trigger Finger Release Surgery.

Cardiac amyloidosis is often preceded by orthopedic manifestations such as carpal tunnel syndrome, and 10% of patients who underwent idiopathic carpal tunnel release surgery will have biopsy-confirmed amyloid deposits in the tenosynovial sheath. Trigger finger is also commonly reported in patients with amyloidosis and involves the same tendon sheath as carpal tunnel syndrome, but the prevalence of amyloid deposition is unclear. This prospective cross-sectional study enrolled 100 patients aged ≥50 years at the time of surgery for idiopathic trigger finger. Patients underwent release surgery, and a sample of the tenosynovium of the affected finger was excised, stained with Congo red, and subtyped with mass spectrometry if amyloid was demonstrated. Further cardiac evaluation was performed in patients with amyloid deposition. Of the 100 patients (mean age 65.5 ± 8.1 years) enrolled, only 2 demonstrated amyloid deposits on Congo red staining. One patient with previous proteinuric kidney disease had fibrinogen A α-chain amyloidosis, and the other patient had untyped amyloidosis. Neither patient had cardiac involvement. A total of 13 of the 100 patients underwent concomitant carpal tunnel release surgery, and 2 of these patients had amyloid deposits in the carpal tunnel with "false-negative" samples from the trigger finger tenosynovium. In conclusion, biopsy during trigger finger release surgery demonstrated a 2% yield for amyloidosis, which is significantly lower than the previously published yield of 10% during carpal tunnel release surgery. This observation has important implications for the development of diagnostic algorithms to screen patients for amyloidosis during orthopedic operations.

Location-dependent change of median nerve mobility in the carpal tunnel of patients with carpal tunnel syndrome.

INTRODUCTION: The purpose of this study was to investigate in vivo median nerve longitudinal mobility in different segments of the carpal tunnel associated with active finger motion in carpal tunnel syndrome (CTS) patients in a comparison with healthy controls. METHODS: Eleven healthy volunteers and 11 CTS patients participated in this study. Dynamic ultrasound images captured location-dependent longitudinal median nerve mobility within the carpal tunnel during finger flexion at the metacarpophalangeal joints using a speckle cross-correlation algorithm. RESULTS: Median nerve longitudinal mobility in the carpal tunnel was significantly smaller in CTS patients (0.0037 ± 0.0011 mm/degree) compared with controls (0.0082 ± 0.0026 mm/degree) (P < .05), especially in the proximal (0.0064 vs 0.0132 mm/degree on average) and middle (0.0033 vs 0.0074 mm/degree on average) carpal tunnel sections. DISCUSSION: Median nerve mobility can potentially serve as a biomechanical marker when diagnosing CTS, or when assessing the effectiveness of surgical and conservative treatments.

Revision Total Wrist Arthroplasty Due to Polyethylene Wear, Metallosis-Induced Carpal Tunnel Syndrome, Distal Ulnar Impingement, and Fourth Carpometacarpal Joint Pain: Case Report and Pitfalls to Avoid.

Background: Total wrist arthroplasty (TWA) is indicated to alleviate pain secondary to arthritis while preserving wrist motion. Despite vigilant measures, TWAs are susceptible to complications. The current case illustrates an array of preventable complications which are addressed through operative technique in a revision setting. Case presentation: The patient was a 72-year-old man who presented with chronic pain at the fourth carpometacarpal joint (CMCJ) and distal radioulnar joint with paresthesias in the median nerve distribution. Surgery was undertaken to address the following complications secondary to a previous TWA: impingement of the native distal ulna on the prosthesis, carpal tunnel due to metallosis and polyethylene synovitis, loose carpal component, and prominent screw at the fourth CMCJ. Surgical correction included open carpal tunnel release with extensive flexor tenosynovectomy, distal ulna resection and implant arthroplasty with shortening, revision of carpal component with bone grafting, and shortening of the ulnar screw to avoid crossing the fourth CMCJ. Within 6 months of the procedure, the patient reported resolution of neuropathic symptoms and pain-free motion of the wrist. Discussion: Preventable complications associated with TWA are individually highlighted. In addition, we compare and contrast our approach and surgical technique to current reported literature. Overall, we provide education and guidance to avoid possible TWA pitfalls. Conclusion: With this case report, we hope to increase TWA knowledge with emphasis on the requirements of judicious patient selection, preoperative planning, meticulous surgical technique, and complication awareness for subsequent optimization of wrist function, stability, and durability.

Long-Term Donor-Site Morbidity After Free, Nonvascularized Toe Phalanx Transfer for Congenital Differences of the Hand.

PURPOSE: Toe phalanx transplantation is a well-established technique for addressing bony deficiency in the reconstruction of hypoplastic digits in patients with congenital differences of the hand. Prior studies have commented on varying degrees of donor-site morbidity, although assessment of morbidity with validated outcome scores is lacking. This study seeks to evaluate donor-site morbidity after toe phalanx harvest using validated outcome measures. METHODS: We identified all children who underwent free, nonvascularized toe phalanx transfer to the hand at our institution from 2001 to 2011. We administered the Oxford Ankle Foot Questionnaire for Children (OXAFQ-C) and the Foot and Ankle Ability Measure (FAAM) to all patients, scaling results according to published scoring instructions. RESULTS: Thirty-six patients with 83 toe phalanx transfers were able to be contacted, with a mean follow-up of 5.3 years (range, 18 months-11.2 years). The results of the OXAFQ-C showed mean scores of 99.96% (Physical), 100% (School and Play), and 96.01% (Emotional). The FAAM mean scores were 99.08% (Sports) and 99.17% (Activities of Daily Living). There were no lower extremity complications during the study period. CONCLUSIONS: In contrast to varying degrees of donor-site morbidity reported in the current literature, this study demonstrates that toe phalanx harvest causes almost no measurable lower extremity morbidity or dysfunction over the mid- to long-term. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Associations of Preoperative Patient Mental Health and Sociodemographic and Clinical Characteristics With Baseline Pain, Function, and Satisfaction in Patients Undergoing Rotator Cuff Repairs.

BACKGROUND: Shoulder pain and dysfunction are common indications for rotator cuff repair surgery, yet the factors that are associated with these symptoms are not fully understood. PURPOSE/HYPOTHESIS: This study aimed to investigate the associations of patient and disease-specific factors with baseline patient-reported outcome measures (PROMs) in patients undergoing rotator cuff repair. We hypothesized that tear size and mental health status, as assessed by the Veterans RAND 12-Item Health Survey mental component score (VR-12 MCS), would be associated with baseline total Penn Shoulder Score (PSS) and its pain, function, and satisfaction subscale scores. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: We prospectively identified 12 patient factors and 12 disease-specific factors as possible statistical predictors for baseline PROMs in patients undergoing surgical repair of superior-posterior rotator cuff tears at a single institution over a 3-year period. Multivariable statistical modeling and Akaike information criterion comparisons were used to investigate the unique associations with, and relative importance of, these factors in accounting for variation in baseline PSS and its subscale scores. RESULTS: A total of 1442 patients who had undergone surgery by 23 surgeons met inclusion criteria, with a baseline median total PSS of 38.5 (pain, 12; function, 24.2; satisfaction, 2). Adjusted R2 in multivariable models demonstrated that the 24 general patient and disease-specific factors accounted for 22% to 24% of the variability in total PSS and its pain and function subscale scores. Large/massive tear size was significantly associated with worse PSS total score and function score but not pain or satisfaction scores. Lower VR-12 MCS was significantly associated with worse total PSS and all 3 subscale scores. Among other factors significantly associated with baseline PROMs were sex, race, preoperative opioid use, years of education, employment status, acromion status, and adhesive capsulitis. Lower VR-12 MCS, preoperative opioid use, female sex, and black race were the factors most strongly associated with baseline PROMs. CONCLUSION: Large/massive tear size, lower VR-12 MCS, and several additional patient and disease-specific factors are associated with baseline PROMs in patients undergoing rotator cuff repair. Further studies are needed to investigate whether these factors will also predict poor postoperative PROMs.

Changes of median nerve conduction, cross-sectional area and mobility by radioulnar wrist compression intervention in patients with carpal tunnel syndrome.

BACKGROUND: Owing to the compressive nature of the neuropathy, patients with carpal tunnel syndrome (CTS) have prolonged distal motor latency (DML), sensory nerve latency (SNL), median nerve swelling and restricted median nerve mobility. The purpose of this study was to noninvasively augment carpal tunnel space using radioulnar wrist compression (RWC) and evaluate its effects on median nerve pathological properties in patients with CTS. It was hypothesized that the RWC intervention would reduce the median nerve DML, SNL and cross-sectional area (CSA) and enhance longitudinal median nerve mobility in patients. with CTS. METHODS: Eleven patients diagnosed with CTS participated in this study. A portable RWC intervention splint was developed to apply 10 N of compressive force across the wrist. Three daily sessions of RWC were performed over 4 weeks of intervention (15 min per session, 45 min per day, 7 days per week). Each 15-min session consisted of three 5-min blocks of RWC, with a 1-min rest in between consecutive blocks. Patients were evaluated at Week 0 (baseline), Week 2 (mid-intervention) and Week 4 (end of intervention). DML and SNL of the median nerve were evaluated using established nerve conduction study techniques. Median nerve CSA at the distal wrist crease was obtained by ultrasound imaging. Median nerve motion associated with finger flexion/extension was captured by dynamic ultrasound imaging and quantified using a speckle cross-correlation algorithm. Finger flexion/extension was recorded using an electrogoniometer. The slope of the regressed linear equation of median nerve displacement as a function of finger flexion angle was used to quantify nerve mobility. RESULTS: Patients with CTS showed significantly decreased DML (p = 0.048) and median nerve CSA (p < 0.001) and increased nerve mobility (p < 0.001) at mid-intervention compared to baseline. However, DML, CSA and mobility of the median nerve did not differ significantly between Weeks 2 and 4 (p = 0.574, 1.00 and 0.139, respectively). Median nerve SNL was not significantly affected throughout the 4-week intervention (p = 0.330 for Week 0 vs. 2; p = 1.00 for Week 2 vs. 4). CONCLUSION: This study revealed that RWC intervention with 10-N force applied to the wrist in the radioulnar direction could restore impaired neurophysiological and biomechanical functions of the median nerve. The beneficial effects of RWC intervention for the median nerve were in evidence after a relatively short period of two weeks. These functional improvements could be explained by intermittent decompression of the median nerve via RWC-induced augmentation of the carpal arch. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: Biomechanically manipulating the carpal tunnel by RWC decompresses the median nerve and has the potential to become an alternative treatment for CTS.

Carpal Tunnel Syndrome: A Potential Early, Red-Flag Sign of Amyloidosis.

Carpal tunnel syndrome (CTS) can be caused by the deposition and accumulation of misfolded proteins called amyloid and is often an early manifestation of systemic amyloidosis. In patients undergoing surgery for idiopathic CTS, a recent study identified amyloidosis by tenosynovial biopsy in 10.2% of men older than 50 years and women older than 60 years; all positive patients had bilateral symptoms. These findings have led to a renewed interest in amyloidosis as an etiology of CTS. The 2 most common systemic amyloidoses, immunoglobulin light chain and transthyretin amyloidosis, affect the heart, nerves, and other organ systems throughout the body including the soft tissues. Patients with cardiac involvement of amyloidosis have an especially poor prognosis if the disease remains unrecognized and untreated. Early diagnosis is paramount, and patients classically present with cardiac disease several years after being operated on by a hand surgeon for carpal tunnel release. Herein, we present a review of amyloidosis as it pertains to CTS and an algorithm for the detection of amyloidosis in patients undergoing carpal tunnel release. Implementation of this straightforward algorithm will allow for early diagnosis of amyloidosis, a group of progressive and lethal diseases.

NON-ENZYMATIC ELECTROCHEMICAL DETECTION OF GLUTAMATE USING TEMPLATED POLYMER-BASED TARGET RECEPTORS.

We present a novel electrochemical biosensing platform for the detection of neurotransmitter glutamate using templated polymer-based target receptors. Our sensing approach demonstrates, for the first time, a non-enzymatic approach without the need of glutamate oxidase, leading to a more specific and rapid response. The proposed detection principle is based on the following two claims: (1) our templated polymer-based receptor results in specific molecular recognition of the target glutamate and, (2) upon target binding, the polymer undergoes a conformation change which can then be measured via electrochemical techniques. This sensing platform has the potential to provide direct monitoring of a variety of non-electroactive species and to eliminate the incorporation of enzymes thereby providing a simpler and more robust alternative to enzyme-based sensors.

Augmented External Fixation of Ulnar Carpometacarpal Joint Fracture Dislocations.

Ulnar-sided carpometacarpal (CMC) joint fracture dislocations are relatively uncommon, frequently associated with fractures of the metacarpal base and/or hamate, and often sustained by young male individuals secondary to striking a hard object. The complexity of ulnar-sided CMC fracture dislocations necessitates careful restitution of anatomic alignment and joint congruency for mobility and stability. Miniaturization of the external fixation device has allowed application to the hand. Spanning external fixation utilizes the principles of "ligamentotaxis"-indirect reduction through distraction forces of capsule-ligamentous structures. Treatment options for ulnar-sided CMC fracture dislocations are varied. Our surgical technique involving an external fixation device is reviewed. Clinical and chart review was performed on the last 10 patients undergoing acute surgical repair of ulnar-sided CMC fracture dislocations with intra-articular comminution by the senior author. Surgical technique used percutaneous Kirschner wire fixation and a spanning, miniature, external fixation device. Minimal follow-up was 1 year. Radiographs from the most recent appointment were evaluated by 2 independent reviewers. Patients rated their level of pain and assessed function using a subjective outcome instrument. Mean total active motion, when comparing traumatized digit to same digit in contralateral hand, was 100%. All fractures healed primarily with maintenance of congruent joint space and without radiographic displacement or arthrosis. Patient satisfaction was high and all patients returned to preinjury level of function. Our study demonstrates the use of an external fixation device in the management of ulnar-sided CMC fracture dislocations to be effective in reestablishing and maintaining normal hand anatomy, reducing pain, increasing function, and preserving motion.

Tenosynovial and Cardiac Amyloidosis in Patients Undergoing Carpal Tunnel Release.

BACKGROUND: Patients with cardiac amyloidosis often have carpal tunnel syndrome that precedes cardiac manifestations by several years. However, the prevalence of cardiac involvement at the time of carpal tunnel surgery has not been established. OBJECTIVES: The authors sought to identify the prevalence and type of amyloid deposits in patients undergoing carpal tunnel surgery and evaluate for cardiac involvement. The authors also sought to determine if patients with soft tissue transthyretin (TTR) amyloid had abnormal TTR tetramer kinetic stability. METHODS: This was a prospective, cross-sectional, multidisciplinary study of consecutive men age ≥50 years and women ≥60 years undergoing carpal tunnel release surgery. Biopsy specimens of tenosynovial tissue were obtained and stained with Congo red; those with confirmed amyloid deposits were typed with mass spectrometry and further evaluated for cardiac involvement with biomarkers, electrocardiography, echocardiography with longitudinal strain, and technetium pyrophosphate scintigraphy. Additionally, serum TTR concentration and tetramer kinetic stability were examined. RESULTS: Of 98 patients enrolled (median age 68 years, 51% male), 10 (10.2%) had a positive biopsy for amyloid (7 ATTR, 2 light chain [AL], 1 untyped). Two patients were diagnosed with hereditary ATTR (Leu58His and Ala81Thr), 2 were found to have cardiac involvement (1 AL, 1 ATTR wild-type), and 3 were initiated on therapy. In those patients who had biopsy-diagnosed ATTR, there was no difference in plasma TTR concentration or tetramer kinetic stability. CONCLUSIONS: In a cohort of patients undergoing carpal tunnel release surgery, Congo red staining of tenosynovial tissue detected amyloid deposits in 10.2% of patients. Concomitant cardiac evaluation identified patients with involvement of the myocardium, allowing for implementation of disease-modifying therapy. (Carpal Tunnel Syndrome and Amyloid Cardiomyopathy; NCT02792790).