Biogeochemical Regimes in Shallow Aquifers Reflect the Metabolic Coupling of the Elements Nitrogen, Sulfur, and Carbon.

Near-surface groundwaters are prone to receive (in)organic matter input from their recharge areas and are known to harbor autotrophic microbial communities linked to nitrogen and sulfur metabolism. Here, we use multi-omic profiling to gain holistic insights into the turnover of inorganic nitrogen compounds, carbon fixation processes, and organic matter processing in groundwater. We sampled microbial biomass from two superimposed aquifers via monitoring wells that follow groundwater flow from its recharge area through differences in hydrogeochemical settings and land use. Functional profiling revealed that groundwater microbiomes are mainly driven by nitrogen (nitrification, denitrification, and ammonium oxidation [anammox]) and to a lesser extent sulfur cycling (sulfur oxidation and sulfate reduction), depending on local hydrochemical differences. Surprisingly, the differentiation potential of the groundwater microbiome surpasses that of hydrochemistry for individual monitoring wells. Being dominated by a few phyla (Bacteroidetes, Proteobacteria, Planctomycetes, and Thaumarchaeota), the taxonomic profiling of groundwater metagenomes and metatranscriptomes revealed pronounced differences between merely present microbiome members and those actively participating in community gene expression and biogeochemical cycling. Unexpectedly, we observed a constitutive expression of carbohydrate-active enzymes encoded by different microbiome members, along with the groundwater flow path. The turnover of organic carbon apparently complements for lithoautotrophic carbon assimilation pathways mainly used by the groundwater microbiome depending on the availability of oxygen and inorganic electron donors, like ammonium.IMPORTANCE Groundwater is a key resource for drinking water production and irrigation. The interplay between geological setting, hydrochemistry, carbon storage, and groundwater microbiome ecosystem functioning is crucial for our understanding of these important ecosystem services. We targeted the encoded and expressed metabolic potential of groundwater microbiomes along an aquifer transect that diversifies in terms of hydrochemistry and land use. Our results showed that the groundwater microbiome has a higher spatial differentiation potential than does hydrochemistry.

Accidental Injection of Freund Complete Adjuvant With Mycobacterium Tuberculosis.

Accidental needlestick injuries are common in laboratory and health care workers. Injection of atypical pathogens, such as those encountered in the animal laboratory setting, may pose considerable problems at the site of inoculation. We present the case of an otherwise healthy laboratory worker who accidentally self-injected Freund complete adjuvant with heat-killed Mycobacterium tuberculosis into her hand, requiring multiple debridement operations over a prolonged treatment course.

Relative Contributions of the Midcarpal and Radiocarpal Joints to Dart-Thrower's Motion at the Wrist.

PURPOSE: To identify the relative contributions of the radiocarpal (RC) and midcarpal (MC) joints to dart-thrower's motion (DTM) of the wrist. METHODS: Six cadaveric upper extremities were fixed to a custom-designed loading jig allowing for pure moment-rotation analysis in 24 different directions of wrist motion. Each specimen was tested in 3 states: intact, simulated radiocarpal fusion (sRCF) and simulated pancarpal fusion (sPCF). Moments of ± 1.5 Nm were applied at each of 24 directions for each state and the resulting wrist rotation recorded. Data from each specimen were reduced to compute the range of motion (ROM) envelopes and the orientation of the ROM for the 3 different states. RESULTS: The ROM was significantly decreased in the sRCF and sPCF groups compared with the intact group in the directions of the pure extension, radial extension, ulnar flexion, and ulnar deviation. No significant difference in ROM was detected between the sRCF and sPCF groups in any direction. The ROM envelopes for the intact, sRCF, and sPCF groups were all oriented obliquely to the axis of pure wrist flexion-extension near a path of ulnar flexion-radial extension, consistent with prior reports on DTM. CONCLUSIONS: Although both simulated fusion types decreased ROM compared with the intact wrist, the principal direction of wrist motion along the path of DTM was not significantly altered by simulated RCF or PCF. CLINICAL RELEVANCE: These findings suggest that the RC and MC joints can each contribute to a similar mechanical axis of motion located along the path of DTM when the other joint has been eliminated via fusion. Surgical options such as partial wrist fusions may maintain the native wrist's mechanical axis if either the RC or the MC joint is preserved, despite significant reduction in overall ROM.

Single- versus double-bundle suture button reconstruction of the forearm interosseous membrane for the chronic Essex-Lopresti lesion.

PURPOSE: Reconstruction of the ruptured interosseous membrane (IOM) is critical to restore forearm stability for the chronic Essex-Lopresti injury. Positive outcomes have been reported following IOM reconstruction with a single-bundle suture button (Mini-Tightrope) construct, although recent work suggests that double-bundle Mini-TightRope® IOM reconstruction is biomechanically superior. The purpose of this study was to determine whether double-bundle Mini-TightRope® reconstruction of the forearm IOM results in superior clinical outcomes to the single-bundle technique. METHODS: Five patients with chronic Essex-Lopresti injuries treated with double-bundle Mini-TightRope® IOM reconstruction were matched to five patients treated with single-bundle Mini-TightRope® reconstruction. Improvement in clinical examination measures and patient-reported outcomes was compared between the groups. RESULTS: Results were good to excellent in all 10 patients. At final follow-up, forearm rotation was significantly better in the single-bundle group, while maintenance of ulnar variance was better in the double-bundle group. No significant differences were noted between the two groups for any other numerical outcomes, and no complications occurred. CONCLUSION: These findings suggest that while IOM reconstruction with a double-bundle Mini-TightRope® construct results in greater resistance to proximal migration of the radius in the intermediate term, there is a modest concomitant loss of forearm rotation when compared to single-bundle reconstruction. LEVEL OF EVIDENCE: Therapeutic Level IV.

Friction Blisters on the Hands Treated Successfully Using 2-Octyl Cyanoacrylate: A Case Report.

BACKGROUND: Friction blisters on the hand are challenging to treat as conventional dressings are prone to saturation, contamination, and loosening with active hand use and other mechanical stresses. Alternative methods and materials for dressing hand blisters warrant exploration. CASE SUMMARY: A 48-year-old male surgeon presented with friction blisters over his bilateral thumbs. The patient complained of significant difficulty in keeping his dressings clean and dry, significant pain with hand hygiene, and functional limitations at work. The patient's blisters were dressed with 2-octyl cyanoacrylate (Dermabond; Ethicon US LLC, Somerville, New Jersey), applied directly onto the wound bed. The patient was able to perform his normal duties immediately, without the need for additional intervention. Six days postapplication, the Dermabond sloughed off, revealing an epithelialized surface. CONCLUSION: Dermabond is a promising agent for dressing unroofed blisters of the hand, as it provides a barrier to moisture and contamination, while allowing the wound to epithelialize, without functional cost.

Distal Interphalangeal Joint Arthrodesis Complicated by Postoperative Infection: A Rare Presentation of Disseminated Herpes Simplex Virus.

Postoperative infection after elective arthrodesis of the interphalangeal joint is an uncommon complication often necessitating urgent debridement. We present the rare case of a female patient with a history of oral herpetic lesions, who underwent elective arthrodesis of the middle and index fingers for treatment of erosive osteoarthritis and subsequently developed a postoperative herpetic infection at the surgical site.

Modified Long Toe Extensor Tendon Harvest for Use as Intercalary Graft in Upper Extremity Reconstruction.

Autograft tendon harvested from the long toe extensors are of great utility as intercalary grafts in upper extremity reconstruction. However, standard full-length harvest is complicated by the presence of extensor retinacula and multiple juncturae between adjacent extensors, which often necessitate extensive dissection, increasing the potential for morbidity. We describe a modified technique for partial harvest of the long toe extensors, which is performed entirely proximal to the superior extensor retinaculum. This technique requires a single incision and provides adequate length of graft for the majority of forearm to fingertip reconstructions. The technique is described in the context of our preliminary cadaver findings, with a case example provided to further illustrate the utility of this technique.

Orthogonal Plate Fixation With Corrective Osteotomy for Treatment of Distal Radius Fracture Malunion.

PURPOSE: To report outcomes of patients with distal radius fracture malunions treated with corrective osteotomy and orthogonal volar and radial "90-90" plate fixation. METHODS: We performed a retrospective review of all patients who underwent distal radius corrective osteotomy and 90-90 fixation from January 2008 through December 2014. Demographic data, injury history, prior treatments, and clinical examination values were recorded. Preoperative radiographic measurements were used to classify the type and severity of deformity. The outcomes were patient-reported pain levels, Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) functional scores, and radiographic outcomes. Secondary outcomes, including complications and the need for additional surgeries, were also noted. RESULTS: Thirty-nine cases (31 extra-articular, 8 combined intra- and extra-articular) were included. At mean postoperative follow-up interval of 4 years, significant improvements were observed clinically in wrist flexion-extension arc, grip strength, pain, and Quick Disabilities of the Arm, Shoulder, and Hand scores. Radiographically, significant postoperative improvements were noted in ulnar variance, radial inclination, intra-articular stepoff, and radial tilt, with volarly and dorsally angulated malunions corrected to 9° and 7° of volar tilt, respectively. Twelve patients (31%) underwent additional surgery, the most common being plate removal in 7 patients, 3 of which involved removal of the radial plate. CONCLUSIONS: For patients with symptomatic malunion of the distal radius, corrective osteotomy with 90-90 plate fixation is an effective treatment option for improving pain and restoring function for both volarly and dorsally angulated malunions, including malunions with an intra-articular component. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Dorsal versus lateral plate fixation of finger proximal phalangeal fractures: a retrospective study.

INTRODUCTION: Unstable proximal phalanx fractures are relatively common injuries but consensus of standard treatment is lacking. Outcomes following plate fixation are highly variable, and it remains unclear which factors are predictive for poorer results. The purpose of this study was to compare dorsal and lateral plate fixation of finger proximal phalangeal fractures with regard to factors that influence the outcome. MATERIALS AND METHODS: A retrospective chart review of proximal phalanx fractures treated with dorsal and lateral plating over a 6-year study interval was performed. Demographic data and injury-specific factors were obtained from review of clinic and therapy notes of 42 patients. Fractures were classified based on the OTA classification using preoperative radiographs. Outcomes investigated included final range of motion (ROM) and total active motion (TAM) of all finger joints. Complications and revision surgeries were also analyzed. RESULTS: Fracture comminution, dorsal and a lateral plate position, occupational therapy, and demographic factors did not significantly influence the outcome, complication, and revision rate after plate fixation of finger proximal phalangeal fractures. CONCLUSIONS: Based on the results of this study, no differences in the outcome of finger proximal phalangeal fractures treated by both dorsal and lateral plate fixation were observed. LEVEL OF EVIDENCE: Therapeutic, retrospective comparative, level III.

Predicting Revision Following In Situ Ulnar Nerve Decompression for Patients With Idiopathic Cubital Tunnel Syndrome.

PURPOSE: To determine the incidence of revision and potential risk factors for needing revision surgery following in situ ulnar nerve decompression for patients with idiopathic cubital tunnel syndrome (CTS). METHODS: We conducted a retrospective chart review of all patients treated at 1 specialty hand center with an open in situ ulnar nerve decompression for idiopathic CTS from January 2006 through December 2010. Revision incidence was determined by identifying patients who underwent additional surgeries for recurrent or persistent ulnar nerve symptoms. Bivariate analysis was performed to determine which variables had a significant influence on the need for revision surgery. RESULTS: Revision surgery was required in 3.2% (7 of 216) of all cases. Age younger than 50 years at the time of index decompression was the lone significant predictor of need for revision surgery. Other patient factors, including gender, diabetes, smoking history, and workers' compensation status were not predictive of the need for revision surgery. Disease-specific variables including nerve conduction velocities, McGowan grading, and predominant symptom type were also not predictive of revision. CONCLUSIONS: For patients with idiopathic CTS, the risk of revision surgery following in situ ulnar nerve decompression is low. However, this risk was increased in patients who were younger than 50 years at the time of the index procedure. The findings of this study suggest that, in the absence of underlying elbow arthritis or prior elbow trauma, in situ ulnar nerve decompression is an effective, minimal-risk option for the initial surgical treatment of CTS. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic III.

Variables Prognostic for Delayed Union and Nonunion Following Ulnar Shortening Fixed With a Dedicated Osteotomy Plate.

PURPOSE: To examine potential risk factors for the development of delayed or nonunion following elective ulnar shortening osteotomy using a dedicated osteotomy plating system. METHODS: We performed a retrospective review of all patients who underwent elective ulnar shortening using the TriMed single osteotomy dynamic compression plating system by 1 of 2 fellowship-trained hand surgeons over a 5-year period. Demographic data and medical, surgical, and social histories were reviewed. Time to bony union was determined radiographically by a blinded reviewer. Bivariate statistical analysis was performed to examine the effect of explanatory variables on the time to union and the incidence of delayed or nonunion. Those variables associated with the development of delayed or nonunion were used in a multivariate logistic regression model. Complications, including the need for additional surgery, were also recorded. RESULTS: Seventy-two ulnar shortening osteotomy procedures were performed in 69 patients. Delayed union, defined as ≥ 6 months to union, occurred in 8 of 72 cases (11%). Of 72 surgeries, 4 (6%) resulted in nonunions, all of which required additional surgery. Hardware removal was performed in 13 of 72 (18%) of the cases. Time to union was significantly increased in smokers (6 ± 3 months) versus nonsmokers (3 ± 1 months). On multivariable analysis, diabetics and active smokers demonstrated a significantly higher risk of developing delayed union or nonunion. Patient age, sex, body mass index, thyroid disease, worker's compensation status, alcohol use, and amount smoked daily did not have an effect on the time to union or the incidence of delayed or nonunion. CONCLUSIONS: Despite the use of an osteotomy-specific plating system, smokers and diabetics were at significantly higher risk for both delayed union and nonunion following elective ulnar shortening osteotomy. Other known risk factors for suboptimal bony healing were not found to have a deleterious effect.

Complications Following Partial and Total Wrist Arthroplasty: A Single-Center Retrospective Review.

PURPOSE: To describe our institution's experience with complications following partial and total wrist arthroplasty (TWA). METHODS: We performed a retrospective review of 105 wrist surgeries in 100 patients who underwent surgery with prosthetic replacement of the distal radius, the proximal carpus, or both at a single institution. Patient factors including age, sex, body mass index, handedness, underlying disease, and previous injury were recorded. Outcomes focused particularly on postoperative complications and need for revision surgery. RESULTS: Forty-seven TWAs, 52 distal radius hemiarthroplasties, and 6 proximal carpal hemiarthroplasties were reviewed with a mean follow-up duration of 35 ± 28 months. Overall complication and revision rates were 51% (53 of 105) and 39% (41 of 105), respectively. Postoperative contracture accounted for the largest number of complications needing additional surgery (20%), followed by component failure (15%). Deep infections occurred in 2 TWAs and 1 distal radius hemiarthroplasty and required removal of hardware, antibiotic spacer placement, and a prolonged course of intravenous antibiotics prior to a definitive operation. Of those patients requiring additional surgery, 41% (n = 10) underwent at least 2 procedures, and 10% (n = 4) underwent at least 6 additional surgeries. CONCLUSIONS: Although TWA and partial wrist arthroplasty are attractive treatment options for the painful arthritic wrist, there remains a noteworthy potential for complications requiring additional surgery. A detailed understanding of these risks is essential for surgeons so that patients may be counseled accordingly and that alternative treatment options may be considered. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Multifocal Neuropathy: Expanding the Scope of Double Crush Syndrome.

Double crush syndrome (DCS), as it is classically defined, is a clinical condition composed of neurological dysfunction due to compressive pathology at multiple sites along a single peripheral nerve. The traditional definition of DCS is narrow in scope because many systemic pathologic processes, such as diabetes mellitus, drug-induced neuropathy, vascular disease and autoimmune neuronal damage, can have deleterious effects on nerve function. Multifocal neuropathy is a more appropriate term describing the multiple etiologies (including compressive lesions) that may synergistically contribute to nerve dysfunction and clinical symptoms. This paper examines the history of DCS and multifocal neuropathy, including the epidemiology and pathophysiology in addition to principles of evaluation and management.

Evaluation and Management of Sleep Disorders in the Hand Surgery Patient.

Despite posing a significant public health threat, sleep disorders remain poorly understood and often underdiagnosed and mismanaged. Although sleep disorders are seemingly unrelated, hand surgeons should be mindful of these because numerous conditions of the upper extremity have known associations with sleep disturbances that can adversely affect patient function and satisfaction. In addition, patients with sleep disorders are at significantly higher risk for severe, even life-threatening medical comorbidities, further amplifying the role of hand surgeons in the recognition of this condition.

Risk factors predicting revision surgery after medial epicondylectomy for primary cubital tunnel syndrome.

BACKGROUND: Medial epicondylectomy (ME) is one of several accepted surgical options for the treatment of cubital tunnel syndrome (CuTS). Although reported outcomes after ME are generally favorable, few data exist regarding which patients are prone to poorer outcomes requiring revision surgery. The goal of this study was to identify risk factors predicting the need for revision surgery after ME for the treatment of CuTS. METHODS: We conducted a retrospective chart review of all patients treated at our institution with ME for CuTS from 2006 through 2011. We identified patients who underwent additional operations for recurrent or persistent ulnar nerve symptoms as the revision cohort. We performed bivariate analysis to determine which variables had a significant influence on the need for revision surgery. We examined qualitative factors associated with revision, including the degree of bony resection performed during the index ME, and intraoperative findings at the time of revision surgery. RESULTS: Revision surgery was required in 13.3% of cases (11 of 83). On bivariate analysis, younger age, associated workers' compensation claims, lesser disease severity, and preoperative opioid use were all significant predictors of the need for revision surgery. Perineural scarring and heterotopic bone formation about the elbow were the 2 most common findings at the time of revision. CONCLUSIONS: For patients with CuTS, the risk of revision surgery after ME is higher in younger patients, patients with less severe disease, patients taking opioid medications preoperatively, and patients with associated workers' compensation claims. LEVEL OF EVIDENCE: Level IV; Case Series; Treatment Study.

Interosseous membrane reconstruction with a suture-button construct for treatment of chronic forearm instability.

BACKGROUND: The purpose of this study was to report outcomes of interosseous membrane (IOM) reconstruction with a suture-button construct for treatment of chronic longitudinal forearm instability. METHODS: We performed a retrospective review with prospective follow-up of patients who underwent ulnar shortening osteotomy and IOM reconstruction with the Mini TightRope device from 2011 through 2014. Bivariate statistical analysis was used for comparison of preoperative and postoperative Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores, range of motion, grip strength, and ulnar variance. Complications and patient satisfaction were also recorded. RESULTS: Ten patients (mean age, 45.3 years) satisfied inclusion criteria: 8 treated for post-traumatic sequelae of Essex-Lopresti-type injuries, 1 for forearm instability secondary to previous elbow surgery, and 1 for instability secondary to trauma and multiple elbow surgeries. Surgeries were performed an average of 28.6 months from initial injury. At mean follow-up of 34.6 months after surgery, significant improvement was observed in elbow flexion-extension arc (+23° vs. preoperatively; P = .007), wrist flexion-extension arc (+22°; P = .016), QuickDASH score (-48; P = .000), and ulnar variance (-3.3 mm; P = .006). Three patients required additional surgery: 1 revision ulnar shortening osteotomy for persistent impingement, 1 revision ulnar osteotomy and Mini TightRope removal for lost forearm supination, and 1 fixation of a radial shaft fracture after a fall. CONCLUSION: IOM reconstruction using a suture-button construct is an effective treatment option for chronic forearm instability.

Recurrent cubital tunnel syndrome treated with revision neurolysis and amniotic membrane nerve wrapping.

BACKGROUND: Perineural scarring of the ulnar nerve is a predominant cause of symptom recurrence after surgical treatment for primary cubital tunnel syndrome (CuTS). We report our preliminary experience in revision ulnar nerve decompression and nerve wrapping with an amniotic membrane allograft adhesion barrier for treatment of recurrent CuTS. METHODS: We performed a retrospective review with prospective follow-up of patients with recurrent CuTS who were treated with revision neurolysis with amniotic membrane nerve wrapping. Preoperative elbow motion, grip and pinch strengths, pain level on the visual analog scale level, and the 11-item version of the Disabilities of the Arm, Shoulder and Hand functional outcome score were compared with postoperative values using paired t testing. Symptom characteristics, physical examination findings, complications, and level of satisfaction were also obtained. RESULTS: Eight patients (mean age, 47.5 years) who had undergone at least 2 prior ulnar nerve operations satisfied study inclusion. At mean postoperative follow-up of 30 months, significant improvements were noted across all patients in visual analog scale pain levels (-3.5 vs. preoperatively; P < .0001), 11-item version of the Disabilities of the Arm, Shoulder and Hand scores (-30 vs. preoperatively; P < .0001), and grip strength (+25 pounds vs. preoperatively; P < .0001). Pinch strength and elbow motion were also significantly improved for those patients with comparative preoperative data available. All patients expressed subjective satisfaction with their results. No adverse reactions or complications occurred in any patients. CONCLUSIONS: Ulnar nerve wrapping with amniotic membrane allograft, when combined with revision neurolysis, was a safe and subjectively effective treatment for patients with debilitating recurrent CuTS.

Three-Dimensional Analysis of Metacarpal Head Articular Defects Created by Headless Screws.

Objectives: Headless screw fixation used to treat metacarpal neck and metacarpal shaft fractures is gaining popularity. The aim of the study is to determine the proportion of the metacarpal head articular surface that is compromised during retrograde insertion of headless screws. Methods: Metacarpal screw fixation through a metacarpal head starting point was performed using fluoroscopic guidance on 14 metacarpals. Headless compression screws, with a tail diameter of 3.6mm, were used. The specimens were subsequently skeletonized and digitized using a 3-dimensional surface scanner. The articular surface defects created by the screws were then determined using computer software. Screw position in the dorsal aspect of the metacarpal head was expressed as a percentage of the total volar-to-dorsal distance. Results: The 14 metacarpals studied consisted of 2 index, 4 long, 4 ring and 4 small metacarpals, taken from 4 hands. The average total metacarpal head surface area was 284.6 mm2 (range, 151.0-462.2 mm2); the average screw footprint in the metacarpal head was 13.3 mm2 (range, 10.3-17.4 mm2), which compromised a mean of 5.0% (3.0-7.8%) of the total cartilaginous metacarpal head surface area. In the sagittal plane, screw placement was found to lie in the dorsal 37.4% of the metacarpal head (range, 20.7-58.6%). Conclusion: The proportion of the articular surface area injured with retrograde insertion of headless compression screws into the metacarpal head is 5.0%. Screw placement is generally in the dorsal 37% of the metacarpal head.

Dual Antegrade Intramedullary Headless Screw Fixation for Treatment of Unstable Proximal Phalanx Fractures.

Background: Although intramedullary headless screw (IMHS) fixation is a promising minimally invasive surgical treatment option for unstable proximal phalanx fractures, a single IMHS may provide inadequate fixation for certain fracture patterns. The purpose of this study was to evaluate the short-term clinical outcomes in a pilot series of patients with proximal phalanx fractures treated with dual antegrade IMHS fixation. Methods: We performed a retrospective chart review of proximal phalanx fractures treated with dual antegrade IMHS fixation with a minimum 1 year of follow-up. Demographic information including patient age, sex, occupation, workers' compensation status, mechanism of injury, hand dominance, and injured digit were obtained. Postoperative outcomes measured included range of motion, grip strength, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) outcome scores, return to full-duty work interval, and complications. Results: Ten fractures in 10 patients (4 male, 6 female) satisfied study inclusion. The mean age of patients was 39 years (range, 20-62), and average follow-up duration was 84 weeks (range, 61-106). Final postoperative total active motion was 258° (range, 245°-270°), mean grip strength was 97% (range, 84%-104%) of the uninjured side, and QuickDASH score was 3.9 (range, 0-13.6). No complications occurred, and no patients required additional intervention. Conclusions: Dual antegrade IMHS fixation of proximal phalanx fractures resulted in excellent postoperative motion, near-normal grip strength, positive self-reported patient outcomes, and no complications with follow-up of at least 1 year. Further study in a larger number of patients is warranted to determine if this promising technique is superior to other modes of fixation.