Targeted Muscle Reinnervation: Factors Predisposing to Successful Pain Score Reduction.

BACKGROUND: Targeted muscle reinnervation (TMR) has demonstrated efficacy in reducing neuroma and chronic pain. In this article, we investigated postoperative outcomes in our patient cohort, with a focus on the role of nonmodifiable factors such as patient age and gender. METHODS: Patients who had extremity TMR from April 2018 to October 2022 were reviewed. Outcomes of interest included patient age, gender, cause and type of amputation, delayed versus immediate TMR, as well as postoperative improvement in pain as assessed by numerical rating score (NRS). RESULTS: A total of 40 patients underwent TMR on 47 limbs. Mean age was 46.2 ± 17.0 years. Delayed TMR (27, 57.4%) was most commonly performed, followed by immediate and delayed-immediate at 11 (23.4%) and 9 (19.1%), respectively. Amputation level was most commonly above-knee in 20 (42.6%) patients, followed by below-knee (12, 25.5%), transhumeral (8, 17.0%), transradial (6, 12.8%), and shoulder (1, 2.1%). The median time interval between amputation and TMR was 12 months. The median preoperative NRS assessing residual limb pain (RLP) for patients who underwent delayed TMR was 10. The median postoperative NRS assessing RLP for all patients was 0 (interquartile range25-75: 0-5) and significantly improved compared with preoperative NRS (P < 0.001). At the last follow-up for limbs that had delayed and delayed-immediate TMR (n = 36), 33 (91.7%) limbs had more than 50% resolution of RLP. There was a significant difference in median postoperative NRS by gender (4 in men and 0 in women) (P < 0.05). Postoperative median NRS also favored younger patients (0, <50 years compared with 4.5, >50 years) (P < 0.05). Multiple linear regression analysis showed that, of different variables analyzed, only male gender and older age were predictive of poorer postoperative outcomes. CONCLUSION: TMR showed high efficacy in our cohort, with improved short-term outcomes in women and younger patients.

Combined Distal Interphalangeal Joint Arthrodesis With Proximal Interphalangeal Joint Arthroplasty or Arthrodesis: Technical Considerations.

Combined distal interphalangeal joint (DIP) arthrodesis with proximal interphalangeal joint (PIP) arthroplasty or arthrodesis presents unique challenges. Although less common than isolated surgery for the DIP and PIP joints, with an aging population, combined DIP and PIP procedures are an increasingly encountered occurrence. Anatomical and morphological studies have provided length and width measurement standards for the middle and distal phalanges, allowing for planning to assess the compatibility of strategies. Besides reviewing anatomical studies to provide length and width guidelines for hardware placement, we will also discuss optimal hardware combinations for combined surgical intervention in the DIP and PIP joints. Conflict may exist between hardware used for the DIP arthrodesis and implants used for the PIP arthroplasty. As an example, if K-wires are used for DIP arthrodesis, any intervention in the PIP joint will be compatible. However, if headless screws are used for DIP arthrodesis, these should ideally not reach proximal to the midpoint of the middle phalanx. Other techniques, such as single or multiple oblique screws, and tension bands are compatible with PIP arthroplasty. Hence, options for management of the PIP joint are dependent on the technique used for DIP arthrodesis.

Factors Affecting Outcomes After Free Functional Gracilis Muscle Transfer for Elbow Flexion in Brachial Plexus Injury: A Systematic Review and Meta-Analysis.

PURPOSE: Free functional gracilis transfer (FFGT) is a useful option for reconstruction of elbow flexion following brachial plexus injury presenting late or with poor outcomes from previous nerve surgery. In this systematic review and meta-analysis, we aimed to investigate variables associated with superior outcomes. The efficacy of single versus double FFGT, where the first FFGT is performed to restore elbow flexion, and the choice of donor nerve for neurotization were evaluated. METHODS: A meta-analysis was conducted, including studies that provided postoperative Medical Research Council (MRC) grade for elbow flexion, Disabilities of the Arm, Shoulder, and Hand and visual analog scale scores, quantitative elbow flexion strength, and range of motion. A random effects meta-regression analysis was performed to identify factors associated with improved outcomes. RESULTS: Thirty-seven studies, with 1,607 patients, were analyzed. Single FFGT was reported in 34 studies (n = 1,398), and double FFGT was reported in 10 studies (n = 209). The mean follow-up duration was 37.3 ± 21.1 months. Following single FFGT, 75.4% and 48.9% achieved MRC grades ≥3 and ≥4, respectively. Following double FFGT, 100% achieved an MRC grade ≥3 and 62.7% ≥4. The likelihood of achieving M3 and M4 was significantly greater for double FFGT. Overall, FFGT innervated by the spinal accessory nerve had significantly better recovery of MRC grade ≥3. When comparing only single and double FFGT innervated by spinal accessory nerve, there was no significant difference in recovery of elbow flexion. The meta-regression analysis showed a significant negative correlation between the patient's age and the probability of achieving an MRC grade of ≥3 and 4. CONCLUSIONS: In the overall analysis encompassing all innervating nerves, double FFGT was superior to single FFGT. Subgroup analysis of single and double FFGT innervated by the spinal accessory nerve showed no significant difference. Increasing age was a significant risk factor for poorer outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Evaluation of Different Surgical Techniques for Revision Cubital Tunnel Release: A Meta-Analysis of Patient-Reported Symptoms.

PURPOSE: Controversy exists regarding the best option for revision surgery in refractory cubital tunnel syndrome (CuTS). The purpose of this systematic review was to evaluate the effectiveness of revision surgery and determine the optimal surgical approach for patients requiring revision surgery for CuTS. METHODS: A literature search was conducted. Characteristics of the included studies were summarized descriptively. The risk ratio between patient-reported preoperative and postoperative outcomes relating to pain, motor, and sensory deficits was calculated. A meta-regression analysis was performed to evaluate the postoperative symptom improvements based on the type of secondary surgery. Random-effects meta-analysis and descriptive statistics were used when appropriate. RESULTS: A total of 471 patients were evaluated in 20 studies. In total, 254 (53.9%) male and 217 (46.1%) female patients, with an average age of 49.2 ± 14.1 years, were included in this study. Pain was the most common symptom (n = 346, 81.6%), followed by sensory and motor dysfunction in 342 (80.6%) and 223 (52.6%) patients, respectively. Meta-analysis comparing preoperative and postoperative symptoms between patients who had submuscular transposition (SMT), subcutaneous transposition (SCT), and neurolysis showed that a significant subgroup difference exists between the types of revision surgery in sensory and motor improvements. Meta-regression showed that SMT was associated with better outcomes compared with SCT in motor and sensory improvements. CONCLUSIONS: Revision surgery for CuTS can be useful for addressing recurrent and persistent symptoms. Compared with neurolysis and SCT, SMT seems to be the superior option for revision surgery, demonstrating substantial improvement in all symptom domains. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Pain Interference Prior to and 1 Year After Surgery for Adult Traumatic Brachial Plexus Injury.

PURPOSE: Pain after brachial plexus injury (BPI) can be severely debilitating and is poorly understood. We hypothesized that pain interference (PI) ("the extent to which pain hinders engagement in life") would be predicted by depression, anxiety, severity of pain symptoms, and poorer preoperative muscle function. METHODS: Among patients in a prospective multicenter BPI cohort study, 37 completed Patient-Reported Outcomes Measurement Information System (PROMIS) PI questionnaires before and 1 year after surgery. At both times, participants completed anxiety and depression questionnaires and BPI-specific measures of pain symptoms, physical limitations, and emotional recovery. Surgeon-graded muscle testing, injury severity, age at the time of injury, body mass index, and time from injury to surgery were included. We performed a bivariate analysis of predictors for preoperative and 1-year PROMIS PI followed by multivariable regression modeling using stepwise selection and Bayesian Information Criterion to select covariates. RESULTS: Before surgery, the mean PROMIS PI score was 60.8 ± 11.0, with moderate correlations between PROMIS PI and depression, as well as between PROMIS PI and functional limitations. At 1 year after surgery, the mean PROMIS PI score was 59.7 ± 9.5. There was no difference in preoperative and 1-year PROMIS PI. There were strong correlations between PROMIS PI and pain symptoms, functional limitations, and emotional aspects of recovery at the 1-year follow-up that remained significant in multivariable regression. There were no notable associations between muscle testing and PI. CONCLUSIONS: Pain interference remained substantial and elevated in BPI patients 1 year after surgery. We noted strong associations between PI and pain symptoms, functional limitations, and emotional aspects of recovery. These findings demonstrate the persistence of pain as a feature throughout life after BPI and that its treatment should be considered a priority alongside efforts to improve extremity function. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognosis IV.

Four-Corner Fusion Versus Proximal Row Carpectomy for Scapholunate Advanced Collapse and Scaphoid Nonunion Advanced Collapse Wrist: A Systematic Review and Meta-Analysis.

PURPOSE: Although proximal row carpectomy (PRC) has increasingly been shown to have superior features to four-corner fusion (4CF), individual surgeons may remain convinced of the superiority of one procedure based on personal experience and individual biases. Hence, we sought to perform an updated meta-analysis with some of the largest studies to date to compare outcomes and complications between these procedures in the treatment of scapholunate advanced collapse and scaphoid nonunion advanced collapse wrists. METHODS: A systematic review and meta-analysis was performed per Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed/MEDLINE, Embase, Web of Science, and Cochrane were queried for articles on PRC and 4CF performed for scapholunate advanced collapse and scaphoid nonunion advanced collapse wrist. Primary outcomes included wrist range of motion; grip strength; outcome measures, including Disabilities of Arm, Shoulder, and Hand and Quick Disabilities of Arm, Shoulder, and Hand scores, Patient-Rated Wrist and Hand Evaluation, and visual analog scale pain scores; and surgical complications. RESULTS: Sixty-one studies reported on 3,174 wrists, of which 54% were treated with PRC and 46% were treated with 4CF. The weighted mean follow-up was 61 months (range, 12-216 months). Meta-analysis comparing PRC and 4CF demonstrated that PRC had significantly greater postoperative extension; ulnar deviation; postoperative improvement in extension, flexion, ulnar deviation; and visual analog scale score. No comparisons showed significant differences in grip strength. The percentage of wrists requiring arthrodesis was 5.2% for PRC and 11% for 4CF. There was an 8.9% (57/640 wrists) 4CF nonunion rate and 2.2% (17/789) hardware removal rate after 4CF. CONCLUSIONS: In the treatment of scapholunate advanced collapse and scaphoid nonunion advanced collapse wrists, PRC results in better outcomes and a lower complication rate compared to 4CF. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Thrombotic Consequences of COVID-19 Infection on Microsurgical Reconstruction.

BACKGROUND: Evidence has shown increased morbidity and mortality for patients with COVID-19 infection within 7 weeks of surgery. However, no studies have specifically investigated the effects of COVID-19 in microsurgical outcomes. This study evaluated thrombotic and overall complications after free tissue transfer for a variety of indications in patients with and without previous COVID-19 infection. METHODS: A retrospective cohort study was performed in adult patients with or without a history of COVID-19 infection who underwent microsurgical reconstruction between 2017 and 2022. Patients with a history of COVID-19 infection were matched to controls based on age, gender, race, body mass index, history of diabetes, coronary artery disease, hypertension, Caprini score, tobacco use, and flap indication. RESULTS: From 2017 to 2022, 35 patients had a documented history of COVID-19. Matched case analysis determined a 4.8 times increased odds ratio of postoperative complications in the COVID-19 group compared with controls (p = 0.002). Significantly, more patients with COVID-19 experienced total or partial flap loss and anastomotic issues (COVID-19: 7/35, Control: 0/35; p < 0.001). There was no significant difference in incidence of VTE (COVID-19: 1/35, Control: 0/35; p = 0.493). Of note, 62.9% of the COVID-19 group were discharged on anticoagulants (versus 14.3% in the control group [p < 0.001]). CONCLUSION: COVID-19 has dire, long-lasting effects on virtually every organ system, chief among them, the microcirculation. Further studies are needed to fully determine the extent and influence of COVID-19 on complex procedures such as free tissue transfer and how to optimize the screening, workup, and postoperative care to guard against the associated thrombotic consequences.

Scalp Closure in Midline Cutis Aplasia-An Absolute Indication for Preoperative Imaging.

The ideal evaluation and treatment of aplasia cutis congenita remains disputed. We present a case of midline scalp cutis aplasia that healed by secondary intention, leaving an area of residual alopecia. There were no clinical indicators of an underlying calvarial defect. Tissue expansion of the scalp was done in preparation for scalp closure. However, on the removal of the expanders and scalp advancement, an unrecognized midline calvarial defect in which a scar tract of herniated dura was found. This resulted in a dural tear, repaired with minimal hemorrhage. However, manipulation of the sagittal sinus resulted in a right subdural hemorrhage followed by cerebral ischemia and a stroke. On the basis of this clinical scenario, we recommend that all cases of midline scalp cutis aplasia undergo preoperative imaging with thin slices of the calvaria before performing scalp advancement-even if the only clinical indication for surgery is scalp alopecia without a palpable skull defect.

The Use of Conventional Lower-Frequency Color Doppler Ultrasound for Flap Planning in the Lower Extremity.

BACKGROUND: Handheld Doppler is often inaccurate in localization of perforators for pedicled and free flaps. Color Doppler ultrasound (CDU), in contrast, allows more accurate mapping and characterization of perforators to facilitate rapid flap harvest. METHODS: Forty-seven flaps harvested from the lower extremity were evaluated preoperatively with CDU by a single surgeon with a conventional low-frequency ultrasound device (Philips Sparq, Cambridge, Mass). Flaps evaluated included profunda artery perforator flaps (n = 36), anterolateral thigh flaps (n = 2), pedicled propeller perforator flaps (n = 7), and toe transfers (n = 2). RESULTS: In all cases where a free profunda artery perforator or anterolateral thigh flap was used, the location of the dominant perforator visualized preoperatively correlated exactly with intraoperative findings. In cases where CDU was used preoperatively to locate a large perforator close to a lower extremity defect for reconstruction with a propeller perforator flap, all perforators could be used, and all flaps were successful. CONCLUSIONS: Preoperative CDU is particularly useful for flap planning where knowledge of the location of the dominant perforator is critical. This includes planning of thin and superthin free flaps, as well as freestyle perforator flaps. Our clinical experience suggests that this technology should be routinely adopted in certain aspects of reconstructive microsurgery.

Ultrasound for Perforator Mapping and Flap Design in the Hand and Upper Extremity.

Duplex ultrasound allows accurate preoperative flap planning through mapping of perforator location and anatomy. In the hand and upper extremity, where thickness of the subcutaneous fat is less compared with other areas of the body, color Doppler ultrasound is particularly sensitive for analyzing the location and characteristics of perforators. In this study, we will first review evidence on use of ultrasound in flap planning. Second, we will provide a technical guide on ultrasound settings for preoperative flap planning. Finally, we will discuss case examples that show the use of ultrasound for accurate perforator mapping to facilitate rapid flap harvest. Color Doppler ultrasound is inexpensive and readily available to be incorporated into the armamentarium of the hand surgeon for preoperative flap planning.

Considerations for Surgical Treatment of Neurogenic Thoracic Outlet Syndrome: A Meta-Analysis of Patient-Reported Outcomes.

PURPOSE: It remains unclear whether first rib resection (FRR), performed via a supraclavicular (SCFRR) or transaxillary (TAFRR) approach, is necessary for patients with neurogenic thoracic outlet syndrome (nTOS). In a systematic review and meta-analysis, we performed a direct comparison of patient-reported functional outcomes following different surgical approaches for nTOS. METHODS: The authors searched PubMed, Embase, Web of Science, Cochrane Library, PROSPERO, Google Scholar, and the gray literature. Data were extracted based on the procedure type. Well-validated patient-reported outcome measures were analyzed in separate time intervals. Random-effects meta-analysis and descriptive statistics were used where appropriate. RESULTS: Twenty-two articles were included, with 11 discussing SCFRR (812 patients), 6 discussing TAFRR (478 patients), and 5 discussing rib-sparing scalenectomy (RSS; 720 patients). The mean difference between preoperative and postoperative Disabilities of the Arm, Shoulder and Hand score was significantly different comparing RSS (43.0), TAFRR (26.8), and SCFRR (21.8). The mean difference between preoperative and postoperative visual analog scale scores was significantly higher for TAFRR (5.3) compared to SCFRR (3.0). Derkash scores were significantly worse for TAFRR compared to RSS or SCFRR. RSS had a success rate of 97.4% based on Derkash score, followed by SCFRR and TAFRR at 93.2% and 87.9%, respectively. RSS had a lower complication rate compared to SCFRR and TAFRR. There was a difference in complication rates: 8.7%, 14.5%, and 3.6% for SCFRR, TAFRR, and RSS, respectively. CONCLUSIONS: Mean differences in Disabilities of the Arm, Shoulder and Hand scores and Derkash scores were significantly better for RSS. Higher complication rates were reported after FRR. Our findings suggest that RSS is an effective option for the treatment of nTOS. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Treatment of complex extremity wounds with MatriDerm: first clinical experience in the US.

OBJECTIVE: Coverage of upper and lower extremity wounds with exposed vital structures such as tendon and bone is reliant on pedicled and free flaps. However, a population of patients with medical comorbidities or other social issues may not be suitable for flap coverage. We present the first in patient clinical experience in the US with MatriDerm (Billerbeck, Germany) for treatment of difficult extremity wounds, all with exposed bone or tendon. METHOD: MatriDerm dermal matrix has been popular in Europe for coverage of wounds. However, MatriDerm only received full approval for use by the US Food and Drug Administration (FDA) in 2021. Here we review our clinical experience. RESULTS: Locations (n=11) treated included forearm (n=1), hand (n=4), leg (n=3), and feet (n=3). Vital structures in wounds exposed included bone (n=3), bone and tendon (n=1), and tendon (n=7). Mean area of the wound treated was 59.2cm2 (range: 2 to 230). In our series, eight out of 11 wounds healed, with MatriDerm only (n=6) or following delayed skin grafting (n=2). Mean time to healing in the patients treated only with MatriDerm was 49 days (range 7 to 84). Mean time to split-thickness skin grafting in the remaining two patients was 44.5 days (range 32 to 57). CONCLUSION: MatriDerm has potential for treatment of complex extremity wounds, which would otherwise require flap coverage, in patients who are not good candidates for flap surgery.

Clinical, electrophysiological, and imaging findings in childhood brachial plexus injury.

AIM: To assess the prognostic capabilities of various diagnostic modalities for childhood brachial plexus injuries (BPIs) and brachial plexus birth injury (BPBI) and postneonatal BPI. METHOD: In this single-center retrospective cross-sectional study, we examined children with BPIs diagnosed or confirmed by electrodiagnostic studies between 2013 and 2020, and compared the prognostic value of various components of the electrophysiologic findings, magnetic resonance imaging (MRI) data, and the Active Movement Scale (AMS). We developed scoring systems for electrodiagnostic studies and MRI findings, including various components of nerve conduction studies and electromyography (EMG) for electrodiagnostic studies. RESULTS: We identified 21 children (10 females and 11 males) aged 8 days to 21 years (mean 8y 6.95mo) who had a total of 30 electrodiagnostic studies, 14 brachial plexus MRI studies, and 10 surgical procedures. Among the diagnostic modalities assessed, brachial plexus MRI scores, EMG denervation scores, and mean total EMG scores were the most valuable in predicting surgical versus non-surgical outcomes. Correspondingly, a combined MRI/mean total EMG score provided prognostic value. INTERPRETATION: Brachial plexus MRI scores and specific electrodiagnostic scores provide the most accurate prognostic information for children with BPI. Our grading scales can assist a multidisciplinary team in quantifying results of these studies and determining prognosis in this setting. WHAT THIS PAPER ADDS: A new scoring system to quantify results of electrodiagnostic and magnetic resonance imaging (MRI) studies is presented. Severity of denervation has good prognostic value for childhood brachial plexus injuries (BPIs). Composite electromyography scores have good prognostic value for childhood BPIs. Brachial plexus MRI has good prognostic value for childhood BPIs.

Lumbar Artery Perforator Flaps: A Systematic Review of Free Tissue Transfers and Anatomical Characteristics.

BACKGROUND: The lumbar artery perforator (LAP) flap has gained popularity as a versatile flap in reconstructive surgery; however, few studies have analyzed salient characteristics of this flap. We set out to provide a comprehensive appraisal of free tissue transfers of LAP flaps with specific attention to anatomic features and clinical outcomes. METHODS: Using preferred reporting items for systematic reviews and meta-analyses guidelines, we identified clinical, radiographic, and cadaveric studies of LAP flaps and assessed outcomes, complications, and anatomic parameters, such as pedicle length, diameter, location, and course. RESULTS: A total of 254 articles were initially reviewed, of which 18 met the final inclusion criteria. Ten studies were primarily concerned with anatomic characteristics, and most clinical studies related to breast reconstruction. The operative durations varied between 4.8 and 9.2 hours. Partial and total flap losses were estimated at 2.6% and 7.6%, respectively. Acute revision rates ranged from 16% to 24% related to hematoma, arterial thrombus, and venous thrombus. Donor-site seromas were frequently encountered in breast reconstruction with an incidence of 17% to 78%. CONCLUSIONS: The LAP flap has demonstrated favorable outcomes in various reconstructive scenarios. The caudal perforators generally offer more pedicle length, greater pedicle diameter, and septocutaneous course and may be better suited for flap design. For breast reconstruction, the LAP flap is a useful alternative to abdominal-based flaps, and special attention should be given to optimizing pedicle length using interposition grafts and methods that minimize seroma formation at the donor site.

Thoracic outlet syndrome: a review.

Thoracic outlet syndrome (TOS) is a rare condition (1-3 per 100,000) caused by neurovascular compression at the thoracic outlet and presents with arm pain and swelling, arm fatigue, paresthesias, weakness, and discoloration of the hand. TOS can be classified as neurogenic, arterial, or venous based on the compressed structure(s). Patients develop TOS secondary to congenital abnormalities such as cervical ribs or fibrous bands originating from a cervical rib leading to an objectively verifiable form of TOS. However, the diagnosis of TOS is often made in the presence of symptoms with physical examination findings (disputed TOS). TOS is not a diagnosis of exclusion, and there should be evidence for a physical anomaly that can be corrected. In patients with an identifiable narrowing of the thoracic outlet and/or symptoms with a high probability of thoracic outlet neurovascular compression, diagnosis of TOS can be established through history, a physical examination maneuvers, and imaging. Neck trauma or repeated work stress can cause scalene muscle scaring or dislodging of a congenital cervical rib that can compress the brachial plexus. Nonsurgical treatment includes anti-inflammatory medication, weight loss, physical therapy/strengthening exercises, and botulinum toxin injections. The most common surgical treatments include brachial plexus decompression, neurolysis, and scalenotomy with or without first rib resection. Patients undergoing surgical treatment for TOS should be seen postoperatively to begin passive/assisted mobilization of the shoulder. By 8 weeks postoperatively, patients can begin resistance strength training. Surgical treatment complications include injury to the subclavian vessels potentially leading to exsanguination and death, brachial plexus injury, hemothorax, and pneumothorax. In this review, we outline the diagnostic tests and treatment options for TOS to better guide clinicians in recognizing and treating vascular TOS and objectively verifiable forms of neurogenic TOS.

Technical Considerations and Clinical Applications of the Free Anterior Branch Split Latissimus Dorsi Flap.

BACKGROUND: The free anterior branch split latissimus dorsi flap has a reliable anatomy and advantages over the traditional latissimus dorsi flap. By preserving the posterior branch of the thoracodorsal nerve, morbidity at the donor site is reduced, preserving shoulder strength. METHODOLOGY: The purpose of this article is to review our experience with the split latissimus flap, describe our surgical technique, and finally review representative cases of reconstruction in different anatomical regions. RESULTS: From April 2017 to October 2020, 39 free split latissimus flaps were performed at a single center. Flaps were performed for coverage in the upper extremity (n = 2), lower extremity (n = 32), and head and neck (n = 5). Flap success rate was 97.4%. Mean dimensions of the flap were 17.0 × 8.3 cm, with a mean area of 145 cm2. CONCLUSIONS: The flap has a broad application and can be utilized in many different reconstructive scenarios including for coverage of defects in the extremities, trunk, and head and neck.

Microbiota composition in bilateral healthy breast tissue and breast tumors.

PURPOSE: Previous reports suggest that a complex microbiome exists within the female human breast that might contribute to breast cancer etiology. The purpose of this pilot study was to assess the variation in microbiota composition by breast side (left versus right) within individual women and compare the microbiota of normal and breast tumor tissue between women. We aimed to determine whether microbiota composition differs between these groups and whether certain bacterial taxa may be associated with breast tumors. METHODS: Bilateral normal breast tissue samples (n = 36) were collected from ten women who received routine mammoplasty procedures. Archived breast tumor samples (n = 10) were obtained from a biorepository. DNA was extracted, amplified, and sequenced. Microbiota data were analyzed using QIIME and RStudio. RESULTS: The most abundant phyla in both tumor and normal tissues were Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria. There were statistically significant differences in the relative abundance of various bacterial taxa between groups. Alpha diversity (Simpson's index) was significantly higher in normal compared to tumor samples (0.968 vs. 0.957, p = 0.022). Based on unweighted UniFrac measures, breast tumor samples clustered distinctly from normal samples (R2 = 0.130; p = 0.01). Microbiota composition in normal samples clustered within women (R2 = 0.394; p = 0.01) and by breast side (left or right) within a woman (R2 = 0.189; p = 0.03). CONCLUSION: Significant differences in diversity between tumor and normal tissue and in composition between women and between breasts of the same woman were identified. These results warrant further research to investigate the relationship between microbiota and breast cancer.

Preoperative Hypoglycemia Increases Infection Risk After Trigger Finger Injection and Release.

BACKGROUND: Diabetes mellitus is a well-known risk factor for infection after trigger finger (TF) injection and/or release. However, the effect of preoperative hypoglycemia before TF injection or release is currently unknown. The purpose of this study is to determine the effects of preoperative hypoglycemia on infection incidence after TF injection or release. METHODOLOGY: A retrospective cohort review between 2007 and 2015 was conducted using a national private payer database within the PearlDiver Supercomputer. Preoperative, fasting, glucose levels were collected for each patient, and these ranged from 20 to 219 mg/dL. Surgical site infection (SSI) rates were determined using International Classification of Diseases, Ninth Revision codes. RESULTS: The query of the PearlDiver database returned 153,479 TF injections, of which 3479 (2.27%) and 6276 (4.09%) had infections within 90 days and 1 year after procedure, respectively. There were 70,290 TF releases identified, with 1887 (2.68%) SSIs captured within 3 months after surgery and 3144 (4.47%) within 1 year after surgery. There was a statistically significant increase in SSI rates in patients with hypoglycemia within 90-day (P = 0.006) and 1-year (P < 0.001) time intervals post-TF injection. Likewise, a statistically significant increase in SSI rate in patients with hypoglycemia undergoing TF release within 1 year after release was seen (P = 0.003). CONCLUSIONS: Hypoglycemia before TF injection or release increases the risk for SSI. Tight glycemic control may be warranted to mitigate this risk. Further studies are needed to investigate the effect of hypoglycemia as an independent risk factor for SSI.

Analysis of Causes for Congenital Ulnar Deviated Thumbs at the Distal Phalanx Level in 157 Thumbs.

PURPOSE: To investigate anatomic abnormalities causing a congenital ulnarly deviated thumb at the distal phalanx. METHODS: A total of 122 children with 157 congenital ulnarly deviated thumbs at the distal phalanges were reviewed, including those with isolated deformity or polydactyly. We analyzed the incidence and characteristics of the underlying anatomic abnormalities as well as the differential diagnoses. RESULTS: Three main causes of an ulnarly deviated thumb were observed. Abnormal hypertrophic epiphyses were found in 96 thumbs. An extra phalanx lying between the normal proximal and distal phalanges was found in 59 thumbs. A previously undescribed cause was found in 2 thumbs with Wassell IV polydactyly, in which an obliquely angled articular surface of the proximal phalanx manifested with ulnar deviation at the interphalangeal joint. Radiographic analysis showed that in cases with abnormal epiphyses, the epiphysis was in good apposition and good alignment with its relevant distal phalanx; the distance from the abnormal epiphysis to the phalanx was usually less than 1 mm. In contrast, in cases of extra phalanges, the distance from the epiphysis to the phalanx averaged more than 2 mm and there was poor apposition between the distal phalanx and the extra bone. CONCLUSIONS: Abnormal hypertrophic epiphysis and triphalangeal thumb are the 2 main causes of a congenital ulnarly deviated thumb. A distance of more than 2 mm between the abnormal bone and the distal phalanx suggests a triphalangeal thumb. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Analysis of Epineurial Lidocaine Injection for Nerve Transfers in a Rat Sciatic Nerve Model.

PURPOSE: Nerve transfers for peripheral nerve injuries can result in variable outcomes. We investigated the neuroprotective effect of epineurial lidocaine injection in the donor nerve prior to transection, with the hypothesis that proximal axon loss would be decreased with consequent increased neuroregeneration and functional recovery. METHODS: A rat sciatic nerve model was used with 4 intervention groups: (1) lidocaine; (2) lidocaine/calcium gluconate (CG); (3) CG; or (4) saline (control). Behavioral testing and qualitative and quantitative histological evaluation was performed at 8 and 12 weeks. Histological assays included transmission electron microscopy, retrograde fluorogold labeling, and whole mount immunostaining. RESULTS: Functional assessments through the sciatic functional index and Basso, Beattie, and Bresnahan scale showed a statistically significant increase in recovery at 8 and 12 weeks with lidocaine treatment. Significantly higher axonal counts were obtained in the lidocaine-treated groups. Fragmentation and increased myelin damage was present in the CG and saline groups. Retrograde fluorogold labeling showed a statistically significant increase in the number of L4-6 dorsal root ganglion neurons in the lidocaine-treated groups. Whole mount immunostaining identified extension of the axonal growth cone past the nerve coaptation site in lidocaine-treated groups, but not in CG and saline groups. CONCLUSIONS: Our results suggest that epineurial lidocaine injection prior to donor nerve transection for nerve transfer has a neuroprotective effect, resulting in increased proximal axon counts and improved functional recovery. CLINICAL RELEVANCE: These findings may have direct clinical application because epineurial lidocaine can be used in surgery as a simple and inexpensive intervention for promoting improved clinical outcomes after nerve transfer.