Mechanistic regulation of planarian shape during growth and degrowth.

Adult planarians can grow when fed and degrow (shrink) when starved while maintaining their whole-body shape. It is unknown how the morphogens patterning the planarian axes are coordinated during feeding and starvation or how they modulate the necessary differential tissue growth or degrowth. Here, we investigate the dynamics of planarian shape together with a theoretical study of the mechanisms regulating whole-body proportions and shape. We found that the planarian body proportions scale isometrically following similar linear rates during growth and degrowth, but that fed worms are significantly wider than starved worms. By combining a descriptive model of planarian shape and size with a mechanistic model of anterior-posterior and medio-lateral signaling calibrated with a novel parameter optimization methodology, we theoretically demonstrate that the feedback loop between these positional information signals and the shape they control can regulate the planarian whole-body shape during growth. Furthermore, the computational model produced the correct shape and size dynamics during degrowth as a result of a predicted increase in apoptosis rate and pole signal during starvation. These results offer mechanistic insights into the dynamic regulation of whole-body morphologies.

A systematic review of nerve grafting, end-to-end repair, and nerve transfer for obturator nerve injuries.

OBJECTIVE: Obturator nerve injury can occur as a complication of gynecologic surgeries, occurring most frequently in patients with endometriosis and genitourinary malignancies. The resulting injury causes paresthesia and major weakness in adduction and atrophy of the adductor group of lower extremity muscles. The objective of this study was to conduct a systematic review and meta-analysis of the effectiveness of end-to-end repair, nerve grafting, and nerve transfer in improving motor function in patients with obturator nerve injury. METHODS: PubMed, Cochrane, Medline, and Embase libraries were searched from May 1994 to August 2020 according to the PRISMA guidelines for articles that present functional outcomes after obturator nerve injury in patients treated with nerve grafting, end-to-end repair, or nerve transfer. RESULTS: A total of 25 patients from 22 studies were included in the study, 15 of whom were treated with end-to-end repair (60%), nine with nerve grafting (36%), and one with nerve transfer (4%). Of the 15 patients with transection data, two had incomplete (13%) and 13 had complete (87%) nerve transections. The patients underwent pelvic lymphadenectomy (n=24) and radical cystectomy (n=1) operations. The mean Medical Research Council (MRC) score was 2.95±1.7 immediately after treatment and 4.77±0.6 at the final follow-up. All patients achieved good outcomes (MRC ≥3) at the final follow-up. The mean MRC score for end-to-end repair (n=15), nerve grafting (n=9), and nerve transfer (n=1) was 4.8±0.6, 4.7±0.8, and 5, respectively. Patients with end-to-end repair had higher immediate post-operative strength than those treated with nerve grafting (p=0.03) and tended to achieve full functional recovery after shorter periods of time (rho=-0.65, p=0.049). Other parameters did not correlate with MRC. CONCLUSION: End-to-end repair, nerve grafting, and nerve transfer are equally effective in restoring function in patients with obturator nerve injury. However, patients treated with end-to-end repair had higher immediate post-operative strength than those treated with nerve grafting.

Imaging Review of Peripheral Nerve Injuries in Patients with COVID-19.

With surging numbers of patients with coronavirus disease 2019 (COVID-19) throughout the world, neuromuscular complications and rehabilitation concerns are becoming more apparent. Peripheral nerve injury can occur in patients with COVID-19 secondary to postinfectious inflammatory neuropathy, prone positioning-related stretch and/or compression injury, systemic neuropathy, or nerve entrapment from hematoma. Imaging of peripheral nerves in patients with COVID-19 may help to characterize nerve abnormality, to identify site and severity of nerve damage, and to potentially elucidate mechanisms of injury, thereby aiding the medical diagnosis and decision-making process. This review article aims to provide a first comprehensive summary of the current knowledge of COVID-19 and peripheral nerve imaging.

Outcomes of Tibial Nerve Repair and Transfer: A Structured Evidence-Based Systematic Review and Meta-Analysis.

Although nerve transfer and repair are well-established for treatment of nerve injury in the upper extremity, there are no established parameters for when or which treatment modalities to utilize for tibial nerve injuries. The objective of our study is to conduct a systematic review of the effectiveness of end-to-end repair, neurolysis, nerve grafting, and nerve transfer in improving motor function after tibial nerve injury. PubMed, Cochrane, Medline, and Embase libraries were queried according to the PRISMA guidelines for articles that present functional outcomes after tibial nerve injury in humans treated with nerve transfer or repair. The final selection included Nineteen studies with 677 patients treated with neurolysis (373), grafting (178), end-to-end repair (90), and nerve transfer (30), from 1985 to 2018. The mean age of all patients was 27.0 ± 10.8 years, with a mean preoperative interval of 7.4 ± 10.5 months, and follow-up period of 82.9 ± 25.4 months. The mean graft repair length for nerve transfer and grafting patients was 10.0 ± 5.8 cm, and the most common donor nerve was the sural nerve. The most common mechanism of injury was gunshot wound, and the mean MRC of all patients was 3.7 ± 0.6. Good outcomes were defined as MRC ≥ 3. End-to-end repair treatment had the greatest number of good outcomes, followed by neurolysis. Patients with preoperative intervals less than 7 months were more likely to have good outcomes than those greater than 7 months. Patients with sport injuries had the highest percentage of good outcomes in contrast to patients with transections and who were in MVAs. We found no statistically significant difference in good outcomes between the use of sural and peroneal donor nerve grafts, nor between age, graft length, and MRC score.

Targeted Muscle Reinnervation Improves Residual Limb Pain, Phantom Limb Pain, and Limb Function: A Prospective Study of 33 Major Limb Amputees.

BACKGROUND: Targeted muscle reinnervation is an emerging surgical technique to treat neuroma pain whereby sensory and mixed motor nerves are transferred to nearby redundant motor nerve branches. In a recent randomized controlled trial, targeted muscle reinnervation was recently shown to reduce postamputation pain relative to conventional neuroma excision and muscle burying. QUESTIONS/PURPOSES: (1) Does targeted muscle reinnervation improve residual limb pain and phantom limb pain in the period before surgery to 1 year after surgery? (2) Does targeted muscle reinnervation improve Patient-reported Outcome Measurement System (PROMIS) pain intensity and pain interference scores at 1 year after surgery? (3) After 1 year, does targeted muscle reinnervation improve functional outcome scores (Orthotics Prosthetics User Survey [OPUS] with Rasch conversion and Neuro-Quality of Life [Neuro-QOL])? METHODS: Data on patients who were ineligible for randomization or declined to be randomized and underwent targeted muscle reinnervation for pain were gathered for the present analysis. Data were collected prospectively from 2013 to 2017. Forty-three patients were enrolled in the study, 10 of whom lacked 1-year follow-up, leaving 33 patients for analysis. The primary outcomes measured were the difference in residual limb and phantom limb pain before and 1 year after surgery, assessed by an 11-point numerical rating scale (NRS). Secondary outcomes were change in PROMIS pain measures and change in limb function, assessed by the OPUS Rasch for upper limbs and Neuro-QOL for lower limbs before and 1 year after surgery. RESULTS: By 1 year after targeted muscle reinnervation, NRS scores for residual limb pain from 6.4 ± 2.6 to 3.6 ± 2.2 (mean difference -2.7 [95% CI -4.2 to -1.3]; p < 0.001) and phantom limb pain decreased from 6.0 ± 3.1 to 3.6 ± 2.9 (mean difference -2.4 [95% CI -3.8 to -0.9]; p < 0.001). PROMIS pain intensity and pain interference scores improved with respect to residual limb and phantom limb pain (residual limb pain intensity: 53.4 ± 9.7 to 44.4 ± 7.9, mean difference -9.0 [95% CI -14.0 to -4.0]; residual limb pain interference: 60.4 ± 9.3 to 51.7 ± 8.2, mean difference -8.7 [95% CI -13.1 to -4.4]; phantom limb pain intensity: 49.3 ± 10.4 to 43.2 ± 9.3, mean difference -6.1 [95% CI -11.3 to -0.9]; phantom limb pain interference: 57.7 ± 10.4 to 50.8 ± 9.8, mean difference -6.9 [95% CI -12.1 to -1.7]; p ≤ 0.012 for all comparisons). On functional assessment, OPUS Rasch scores improved from 53.7 ± 3.4 to 56.4 ± 3.7 (mean difference +2.7 [95% CI 2.3 to 3.2]; p < 0.001) and Neuro-QOL scores improved from 32.9 ± 1.5 to 35.2 ± 1.6 (mean difference +2.3 [95% CI 1.8 to 2.9]; p < 0.001). CONCLUSIONS: Targeted muscle reinnervation demonstrates improvement in residual limb and phantom limb pain parameters in major limb amputees. It should be considered as a first-line surgical treatment option for chronic amputation-related pain in patients with major limb amputations. Additional investigation into the effect on function and quality of life should be performed. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Continuous Dynamic Modeling of Regulated Cell Adhesion: Sorting, Intercalation, and Involution.

Cell-cell adhesion is essential for tissue growth and multicellular pattern formation and crucial for the cellular dynamics during embryogenesis and cancer progression. Understanding the dynamical gene regulation of cell adhesion molecules (CAMs) responsible for the emerging spatial tissue behaviors is a current challenge because of the complexity of these nonlinear interactions and feedback loops at different levels of abstraction-from genetic regulation to whole-organism shape formation. To extend our understanding of cell and tissue behaviors due to the regulation of adhesion molecules, here we present a novel, to our knowledge, model for the spatial dynamics of cellular patterning, growth, and shape formation due to the differential expression of CAMs and their regulation. Capturing the dynamic interplay between genetic regulation, CAM expression, and differential cell adhesion, the proposed continuous model can explain the complex and emergent spatial behaviors of cell populations that change their adhesion properties dynamically because of inter- and intracellular genetic regulation. This approach can demonstrate the mechanisms responsible for classical cell-sorting behaviors, cell intercalation in proliferating populations, and the involution of germ layer cells induced by a diffusing morphogen during gastrulation. The model makes predictions on the physical parameters controlling the amplitude and wavelength of a cellular intercalation interface, as well as the crucial role of N-cadherin regulation for the involution and migration of cells beyond the gradient of the morphogen Nodal during zebrafish gastrulation. Integrating the emergent spatial tissue behaviors with the regulation of genes responsible for essential cellular properties such as adhesion will pave the way toward understanding the genetic regulation of large-scale complex patterns and shapes formation in developmental, regenerative, and cancer biology.

Targeted Muscle Reinnervation Treats Neuroma and Phantom Pain in Major Limb Amputees: A Randomized Clinical Trial.

OBJECTIVE: To compare targeted muscle reinnervation (TMR) to "standard treatment" of neuroma excision and burying into muscle for postamputation pain. SUMMARY BACKGROUND DATA: To date, no intervention is consistently effective for neuroma-related residual limb or phantom limb pain (PLP). TMR is a nerve transfer procedure developed for prosthesis control, incidentally found to improve postamputation pain. METHODS: A prospective, randomized clinical trial was conducted. 28 amputees with chronic pain were assigned to standard treatment or TMR. Primary outcome was change between pre- and postoperative numerical rating scale (NRS, 0-10) pain scores for residual limb pain and PLP at 1 year. Secondary outcomes included NRS for all patients at final follow-up, PROMIS pain scales, neuroma size, and patient function. RESULTS: In intention-to-treat analysis, changes in PLP scores at 1 year were 3.2 versus -0.2 (difference 3.4, adjusted confidence interval (aCI) -0.1 to 6.9, adjusted P = 0.06) for TMR and standard treatment, respectively. Changes in residual limb pain scores were 2.9 versus 0.9 (difference 1.9, aCI -0.5 to 4.4, P = 0.15). In longitudinal mixed model analysis, difference in change scores for PLP was significantly greater in the TMR group compared with standard treatment [mean (aCI) = 3.5 (0.6, 6.3), P = 0.03]. Reduction in residual limb pain was favorable for TMR (P = 0.10). At longest follow-up, including 3 crossover patients, results favored TMR over standard treatment. CONCLUSIONS: In this first surgical RCT for the treatment of postamputation pain in major limb amputees, TMR improved PLP and trended toward improved residual limb pain compared with conventional neurectomy. TRIAL REGISTRATION: NCT02205385 at ClinicalTrials.gov.

Prognostic value of needle electromyography in traumatic brachial plexus injury.

INTRODUCTION: In this study we aimed to determine whether needle electromyographic assessment of voluntary motor unit recruitment in traumatic brachial plexus injuries could predict spontaneous motor recovery. METHODS: A retrospective study was performed on patients with brachial plexus injury affecting deltoid, supraspinatus/infraspinatus, and biceps brachii. The outcome measure was strength on manual muscle testing at least 1 year after injury. Good outcome was considered strength >3/5 on the Medical Research Council (MRC) scale. RESULTS: No muscles with no recruitment (n = 27) at 1-9 months improved to MRC 4/5 strength at a mean of 2.0 years postinjury. Twenty-five percent of muscles with discrete or severely reduced recruitment (n = 8) regained strength to >3/5 at a mean of 1.4 years postinjury (P = .047). DISCUSSION: Absent voluntary motor unit potential recruitment at 1-9 months predicted poor prognosis for spontaneous recovery. A high percentage of patients with discrete recruitment did not improve to >3/5 strength. These patients should be considered for early nerve transfer surgery.

Biomechanical Properties of a Novel Mesh Suture in a Cadaveric Flexor Tendon Repair Model.

PURPOSE: Conventional suture repairs, when stressed, fail by suture rupture, knot slippage, or suture pull-through, when the suture cuts through the intervening tissue. The purpose of this study was to compare the biomechanical properties of flexor tendon repairs using a novel mesh suture with traditional suture repairs. METHODS: Sixty human cadaveric flexor digitorum profundus tendons were harvested and assigned to 1 of 3 suture repair groups: 3-0 and 4-0 braided poly-blend suture or 1-mm diameter mesh suture. All tendons were repaired using a 4-strand core cruciate suture configuration. Each tendon repair underwent linear loading or cyclic loading until failure. Outcome measures included yield strength, ultimate strength, the number of cycles and load required to achieve 1-mm and 2-mm gap formation, and failure. RESULTS: Mesh suture repairs had significantly higher yield and ultimate force values when compared with 3-0 and 4-0 braided poly-blend suture repairs under linear testing. The average force required to produce repair gaps was significantly higher in mesh suture repairs than in conventional suture. Mesh suture repairs endured a significantly greater number of cycles and force applied before failure compared with both 3-0 and 4-0 conventional suture. CONCLUSIONS: This ex vivo biomechanical study of flexor tendon repairs using a novel mesh suture reveals significant increases in average yield strength, ultimate strength, and average force required for gap formation and repair failure with mesh suture repairs compared with conventional sutures. CLINICAL RELEVANCE: Mesh suture-based flexor tendon repairs could lead to improved healing at earlier time points. The findings could allow for earlier mobilization, decreased adhesion formation, and lower rupture rates after flexor tendon repairs.

Wrist arthrodesis with the medial femoral condyle flap: Outcomes of vascularized bone grafting for osteomyelitis.

BACKGROUND: Osteomyelitis of the wrist is rare but destructive. Subsequent bone defects often require vascularized bone for successful healing. Recent literature has pointed to the successful use of the medial femoral condylar (MFC) flap for difficult non-unions, yet it has not been specifically described for wrist fusion. We present our experience with this technique for limited and complete wrist arthrodesis. PATIENTS AND METHODS: We reviewed 4 cases of radiocarpal bone loss from osteomyelitis. All cases utilized debridement of nonviable tissues, and at least 6 weeks of intravenous antibiotics, followed by vascularized bone grafting with a MFC flap. The flap was based on the horizontal periosteal branch of the descending geniculate artery, and utilized to directly bridge the bony defects following resection. RESULTS: Three patients healed primarily, and 1 patient required secondary cancellous bone grafting to reach union. One patient required revision of the donor site closure. None of the patients had a recurrence of infection or other complications. Average follow up was 8.5 months after reconstruction. Average time to union was 11.5 weeks. Three patients demonstrated full composite fist, and 1 patient had incomplete finger range of motion following several flexor and extensor tendon grafts. CONCLUSIONS: These cases illustrate the use of the MFC in wrist arthrodesis after osteomyelitis defects. In all cases, there was complete union in a short time, no recurrence of infection, and low donor-site morbidity.

Vascularized Composite Allotransplantation of the Elbow Joint: A Cadaveric Study.

BACKGROUND: Surgical options for the unreconstructable elbow are limited to arthrodesis, total arthroplasty, or osteoarticular allograft reconstruction. Each of these options is limited by severe functional impairment and/or high complication rates. Vascularized allotransplantation of the elbow joint has the potential to mitigate these complications. In this study, we describe our technique for harvesting the elbow for vascularized joint transplantation and demonstrate the flap's vascularity using contrast angiography. METHODS: Anatomical studies were used to design and harvest a vascularized elbow joint flap pedicled on the brachial vessels in 10 cadaveric arms. Diaphyseal blood supply is provided by 3 nutrient arteries, and periarticular supply arises from the various collateral arteries of the arm and recurrent arteries of the forearm. The brachialis and supinator, and their respective nerves, were included as functional muscles because of their intimate association with critical vasculature. Tendinous insertions of the biceps and triceps, as well as the flexor/pronator and extensor origins, were preserved for repair in the transplant recipient. Both lateral arm and radial forearm flaps were preserved to aid in soft tissue inset as well as vascular/immunologic monitoring. Contrast angiography of each dissected specimen was performed to assess the location of the nutrient vessels and assess flap vascularity, as indicated by filling of the critical extraosseous and endosteal vessels. RESULTS: Angiographic imaging of 10 specimens demonstrated that this flap dissection preserves the nutrient endosteal supply to the humeral, radial, and ulnar diaphysis, in addition to the critical extraosseous arterial structures perfusing the elbow joint and periarticular tissues. From proximal to distal, these arteries are the musculoperiosteal radial, posterior branch of the radial collateral, inferior ulnar collateral, recurrent interosseous, radial recurrent, and the anterior and the posterior ulnar recurrent. CONCLUSIONS: Vascularized composite allotransplantation of the elbow joint holds promise as a motion and function preserving option for young, high-demand patients with a sensate and functional hand, who would otherwise be limited by the restrictions of total elbow arthroplasty or fusion. In this study, we propose a flap design and technique for harvest and also offered vascular imaging-based evidence that this flap is adequately vascularized.

Use of Processed Nerve Allografts to Repair Nerve Injuries Greater Than 25 mm in the Hand.

Processed nerve allografts (PNAs) have been demonstrated to have improved clinical results compared with hollow conduits for reconstruction of digital nerve gaps less than 25 mm; however, the use of PNAs for longer gaps warrants further clinical investigation. Long nerve gaps have been traditionally hard to study because of low incidence. The advent of the RANGER registry, a large, institutional review board-approved, active database for PNA (Avance Nerve Graft; AxoGen, Inc, Alachua, FL) has allowed evaluation of lower incidence subsets. The RANGER database was queried for digital nerve repairs of 25 mm or greater. Demographics, injury, treatment, and functional outcomes were recorded on standardized forms. Patients younger than 18 and those lacking quantitative follow-up data were excluded. Recovery was graded according to the Medical Research Council Classification for sensory function, with meaningful recovery defined as S3 or greater level. Fifty digital nerve injuries in 28 subjects were included. There were 22 male and 6 female subjects, and the mean age was 45. Three patients gave a previous history of diabetes, and there were 6 active smokers. The most commonly reported mechanisms of injury were saw injuries (n = 13), crushing injuries (n = 9), resection of neuroma (n = 9), amputation/avulsions (n = 8), sharp lacerations (n = 7), and blast/gunshots (n = 4). The average gap length was 35 ± 8 mm (range, 25-50 mm). Recovery to the S3 or greater level was reported in 86% of repairs. Static 2-point discrimination (s2PD) and Semmes-Weinstein monofilament (SWF) were the most common completed assessments. Mean s2PD in 24 repairs reporting 2PD data was 9 ± 4 mm. For the 38 repairs with SWF data, protective sensation was reported in 33 repairs, deep pressure in 2, and no recovery in 3. These data compared favorably with historical data for nerve autograft repairs, with reported levels of meaningful recovery of 60% to 88%. There were no reported adverse effects. Processed nerve allograft can be used to reconstruct long gap nerve defects in the hand with consistently high rates of meaningful recovery. Results for PNA repairs of digital nerve injuries with gaps longer than 25 mm compare favorably with historical reports for nerve autograft repair but without donor site morbidity.

Complications Within 30 Days of Hand Surgery: An Analysis of 10,646 Patients.

PURPOSE: The American College of Surgeons Surgical Quality Improvement Program database collects detailed and validated data on demographics, comorbidities, and 30-day postoperative outcomes of patients undergoing operations in most subspecialties. This dataset has been previously used to quantify complications and identify risk factors in other surgical subspecialties. We sought to determine the incidence of postoperative complications following hand surgery and to identify factors associated with increased risk of complications in order to focus preventive strategies. METHODS: National Surgical Quality Improvement Program data from 2006 to 2011 were queried using 302 hand-specific Current Procedural Technology codes. Descriptive statistics were calculated for the population, and potential risk factors and patient characteristics were analyzed for their association with complications in the 30-day postoperative period using both univariate and multivariate analyses. RESULTS: There were 208 hand-specific Current Procedural Technology codes represented in the data, and of these, 84 were associated with at least 1 complication. The overall incidence of complications within 30 days of hand surgery was 2.5% (95% confidence interval, 2.2%-2.8%). In univariate analysis, older age, diabetes, chronic obstructive pulmonary disease, congestive heart failure, atherosclerosis, steroids, bleeding disorder, increasing American Society of Anesthesiologists class, increasing wound class, emergency procedure, longer operative time, and preoperative transfusion were associated with significantly higher risk of complications, and local anesthesia and outpatient surgery were associated with lower risk. In the multivariate model, male sex, increasing American Society of Anesthesiologists class, wound class 4, and preoperative transfusion were associated with significantly higher risk, and outpatient surgery was associated with significantly lower risk. The most common complication was surgical-site infection (1.2%). CONCLUSIONS: The incidence of complications was low, with overall health status being more important than specific comorbidities in predicting complication risk. This information may be valuable in counseling patients before surgery and in identifying patients at higher risk for complications following hand surgery. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Comparing the hydrosurgery system to conventional debridement techniques for the treatment of delayed healing wounds: a prospective, randomised clinical trial to investigate clinical efficacy and cost-effectiveness.

In these uncertain times of high health care costs, clinicians are looking for cost-effective devices to employ in their everyday practices. In an effort to promote cost-effective and proper wound repair, the hydrosurgical device allows accurate debridement of only unwanted tissue while precisely conserving viable structures for eventual repair. This prospective, randomised study compared procedures using the hydrosurgery system (VERSAJET™) with conventional debridement in order to assess clinical efficacy and cost-effectiveness when treating subjects with chronic wounds. A total of 40 subjects were recruited. There was no difference in time to achieve stable wound closure between the treatment groups (P = 0·77). There were no significant differences between the two groups in terms of cost of the first operative procedure (P = 0·28), cost of surgical procedures during the study (P = 0·51), cost of study treatment (P = 0·29) or cost to achieve stable wound closure (P = 0·85). There were no differences in quantitative bacterial counts after debridement with either methods (P = 0·376). However, the time taken for the first excision procedure was significantly faster using the hydrosurgery system (VERSAJET) when compared with conventional debridement (P < 0·001). The total excision time for all procedures was significantly less for the Hydrosurgery group than for the conventional group (P = 0·005). Also, the Hydrosurgery group demonstrated significantly less intraoperative blood loss than conventional group for all procedures (P = 0·003). In this study, although there were no differences in time to stable wound closure or bacterial reduction between the two groups, the hydrosurgery system (VERSAJET) did offer advantages in terms of operative times and intraoperative blood loss and was cost-neutral, despite the handpiece cost.

Does targeted nerve implantation reduce neuroma pain in amputees?

BACKGROUND: Symptomatic neuroma occurs in 13% to 32% of amputees, causing pain and limiting or preventing the use of prosthetic devices. Targeted nerve implantation (TNI) is a procedure that seeks to prevent or treat neuroma-related pain in amputees by implanting the proximal amputated nerve stump onto a surgically denervated portion of a nearby muscle at a secondary motor point so that regenerating axons might arborize into the intramuscular motor nerve branches rather than form a neuroma. However, the efficacy of this approach has not been demonstrated. QUESTIONS/PURPOSES: We asked: Does TNI (1) prevent primary neuroma-related pain in the setting of acute traumatic amputation and (2) reduce established neuroma pain in upper- and lower-extremity amputees? METHODS: We retrospectively reviewed two groups of patients treated by one surgeon: (1) 12 patients who underwent primary TNI for neuroma prevention at the time of acute amputation and (2) 23 patients with established neuromas who underwent neuroma excision with secondary TNI. The primary outcome was the presence or absence of palpation-induced neuroma pain at last followup, based on a review of medical records. The patients presented here represent 71% of those who underwent primary TNI (12 of 17) and 79% of those who underwent neuroma excision with secondary TNI (23 of 29 patients) during the period in question; the others were lost to followup. Minimum followup was 8 months (mean, 22 months; range, 8-60 months) for the primary TNI group and 4 months (mean, 22 months; range, 4-72 months) for the secondary TNI group. RESULTS: At last followup, 11 of 12 patients (92%) after primary TNI and 20 of 23 patients (87%) after secondary TNI were free of palpation-induced neuroma pain. CONCLUSIONS: TNI performed either primarily at the time of acute amputation or secondarily for the treatment of established symptomatic neuroma is associated with a low frequency of neuroma-related pain. By providing a distal target for regenerating axons, TNI may offer an effective strategy for the prevention and treatment of neuroma pain in amputees.

Targeted muscle reinnervation: a novel approach to postamputation neuroma pain.

BACKGROUND: Postamputation neuroma pain can prevent comfortable prosthesis wear in patients with limb amputations, and currently available treatments are not consistently effective. Targeted muscle reinnervation (TMR) is a decade-old technique that employs a series of novel nerve transfers to permit intuitive control of upper-limb prostheses. Clinical experience suggests that it may also serve as an effective therapy for postamputation neuroma pain; however, this has not been explicitly studied. QUESTIONS/PURPOSES: We evaluated the effect of TMR on residual limb neuroma pain in upper-extremity amputees. METHODS: We conducted a retrospective medical record review of all 28 patients treated with TMR from 2002 to 2012 at Northwestern Memorial Hospital/Rehabilitation Institute of Chicago (Chicago, IL, USA) and San Antonio Military Medical Center (San Antonio, TX, USA). Twenty-six of 28 patients had sufficient (> 6 months) followup for study inclusion. The amputation levels were shoulder disarticulation (10 patients) and transhumeral (16 patients). All patients underwent TMR for the primary purpose of improved myoelectric control. Of the 26 patients included in the study, 15 patients had evidence of postamputation neuroma pain before undergoing TMR. RESULTS: Of the 15 patients presenting with neuroma pain before TMR, 14 experienced complete resolution of pain in the transferred nerves, and the remaining patient's pain improved (though did not resolve). None of the patients who presented without evidence of postamputation neuroma pain developed neuroma pain after the TMR procedure. All 26 patients were fitted with a prosthesis, and 23 of the 26 patients were able to operate a TMR-controlled prosthesis. CONCLUSIONS: None of the 26 patients who underwent TMR demonstrated evidence of new neuroma pain after the procedure, and all but one of the 15 patients who presented with preoperative neuroma pain experienced complete relief of pain in the distribution of the transferred nerves. TMR offers a novel and potentially more effective therapy for the management of neuroma pain after limb amputation.

Thin and Thinned Anterolateral Thigh Flaps for Upper Extremity Reconstruction.

Upper extremity reconstruction remains challenging due to the high functional and esthetic demands of this location. The anterolateral thigh (ALT) flap is a workhorse flap for microsurgical reconstruction of the upper extremity and can be elevated in various planes depending on desired thickness of the flap. Microsurgical reconstruction of the upper extremity often benefits from a thin flap that can resurface the extremity, which can provide improved functional and esthetic outcomes. This article reviews the anatomy, preoperative planning, and operative technique, as well as presents 4 cases to illustrate the outcomes and benefits of thin and thinned ALT flaps.

Management of Superficial and Deep Peroneal Nerve Neuromas with Targeted Muscle Reinnervation in Nonamputees: Operative Technique and Early Outcomes.

Background: Targeted muscle reinnervation (TMR), a surgical technique developed by the senior authors that coapts proximal ends of nerves to distal motor nerves of adjacent muscles, has demonstrated efficacy in the treatment and prevention of neuroma pain. The objective of this study is to describe the surgical technique for TMR of the superficial peroneal nerve (SPN) and deep peroneal nerve (DPN) in nonamputee patients and provide data on postoperative functional outcomes. Methods: A single-institution retrospective chart review was performed between March 2018 and April 2021. Patients were de-identified and included if they were nonamputees receiving TMR for pain in the peroneal nerve distribution. Data extracted included demographic information, symptoms before operation, relevant nerve coaptation, peri-, and postoperative complications, and long-term functional outcomes. Results: Of the 19 patients reviewed, 11 patients underwent TMR of the SPN alone: eight had complete resolution of their symptoms; two indicated partial improvement in pain; and one patient had no improvement. Four patients underwent TMR of the DPN alone: two patients had complete resolution of their pain, and two patients had partial improvement with pain. Four patients underwent TMR of both the SPN/DPN: two patients had complete resolution of their symptoms, and two patients were noted to have significant improvement but had persistent pain from prior foot operations. Average follow-up time was 260 days. Conclusions: TMR is a successful technique in the management of SPN and DPN neuroma pain. Our technique revealed excellent clinical outcomes, no procedure-specific complications, and improved subjective pain reports.

Preference Signaling and the Integrated Plastic Surgery Match: A National Survey Study.

OBJECTIVE: Rooted in economics market strategies, preference signaling was introduced to the Plastic Surgery Common Application (PSCA) in 2022 for integrated plastic surgery residency applicants. This study surveyed program and applicant experience with preference signaling and assessed how preference signals influenced likelihood of interview invitations. DESIGN: Two online surveys were designed and distributed to all program directors and 2022-2023 applicants to integrated plastic surgery. Opinions regarding the utility of preference signaling were solicited, and the influence of preference signals on likelihood of interview offers was assessed. SETTING: All integrated plastic surgery programs. PARTICIPANTS: All 88 program directors and 2022-2023 applicants to integrated plastic surgery. RESULTS: A total of 45 programs and 99 applicants completed the survey (response rates, 54.2% and 34.2%, respectively). Overall, 79.6% of applicants and 68.9% of programs reported that preference signals were a useful addition to the application cycle. Programs reported that 41.4% of students who sent preference signals received interview offers, compared to 84.6% of home students, 64.8% of away rotators, and 7.1% of other applicants; overall, students who signaled were 5.8 times more likely to receive an interview offer compared to students who were not home students and did not rotate or signal. After multivariable adjustment, programs with higher Doximity rankings, numbers of away rotators, and numbers of integrated residents per year received more preference signals (all p < 0.05). CONCLUSIONS: Applicants and programs report that preference signaling was a useful addition to the integrated plastic surgery application cycle. Sending preference signals resulted in a higher likelihood of interview offers among nonrotators. Preference signaling may be a useful tool to reduce congestion in the integrated plastic surgery application cycle.