Active nerve management for above the knee amputation: A comparison of through the wound versus posterior approach.

Targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI) are used to prevent or treat neuromas in amputees. TMR for above-the-knee amputation (AKA) is most commonly performed through a posterior incision rather than the stump wound because recipient motor nerves are primarily located in the proximal third of the thigh. When preventative TMR is performed with concurrent AKA, a posterior approach requires intraoperative repositioning and an additional incision. The purpose of this study was to evaluate feasibility of TMR and operative times for nerve management performed through the wound compared to a posterior approach in AKA patients to guide surgical decision-making. Patients who underwent AKA with TMR between 2018-2023 were reviewed. Patients were divided into two groups: TMR performed through the wound (Group I) and TMR performed through a posterior approach (Group II). If a nerve was unable to undergo coaptation for TMR due to the lack of suitable donor motor nerves, RPNI was performed. Eighteen patients underwent AKA with nerve management were included from Group I (8 patients) and Group II (10 patients). TMR coaptations performed on distinct nerves was 1.5 ± 0.5 in Group I compared to 2.6 ± 0.5 in Group II (p = 0.001). Operative time for Group I was 200.7 ± 33.4 min compared to 326.5 ± 37.1 min in Group II (p = 0.001). TMR performed through the wound following AKA requires less operative time than a posterior approach. However, since recipient motor nerves are not consistently found near the stump, RPNI may be required with TMR whereas the posterior approach allows for more TMR coaptations.

Revisiting Bipedicled Flaps for Lower Extremity Distal Third Defects.

BACKGROUND: Lower extremity reconstruction of the distal third of the leg is challenging. Free tissue transfer is the criterion standard. The COVID-19 pandemic encouraged seeking alternatives for resource consuming procedures. Bipedicled flaps are flaps with a dual-source subdermal perfusion. The purpose of this study was to assess outcomes of patients who had bipedicled flaps primary or auxiliary local flap for distal third leg/foot reconstruction. METHODS: A retrospective review of patients undergoing lower extremity reconstruction (2020-2021) was performed. Inclusion criteria were patients older than 18 years with lower extremity wounds secondary to traumatic injury for which bipedicled flaps were used in the reconstruction. Exclusion criteria included lower extremity wounds secondary to peripheral vascular disease or diabetes. RESULTS: Fourteen patients were included in the study. All patients had distal third of the leg/foot wounds, and 12 patients (87.5%) had concurrent leg fractures. In 8 patients (57.1%), the bipedicled flap was used to decrease the wound size and facilitate another concurrent flap: hemisoleus (21.4%), anterior tibialis muscle turnover (14.3%), medial plantar artery (14.3%), and posterior tibial artery perforator (14.3%). Mean wound size for bipedicle flaps used alone was 42.0 ± 18.3 cm2, whereas wounds that required a bipedicled flap with an additional flap were 69.9 ± 80.8 cm2 (P = 0.187). Two patients had partial flap necrosis (14.3%) but healed their defect. One patient had nonunion (7.1%). Limb salvage rate was 100%. CONCLUSIONS: Bipedicled flaps can be used as an alternative to free flaps in distal third leg/foot defects in select patients. If distal extremity wounds cannot be covered with a bipedicled flap alone, the flap can be used an accessory flap to facilitate reconstruction with other local flaps.

The Effect of Free versus Local Flaps on Time to Union in Open Tibia Fractures.

BACKGROUND: Early soft-tissue reconstruction of open fractures has been shown to decrease infection rates and improve rates of bony union. The purpose of this study was to compare the rates and time to union of open tibia fractures that underwent soft-tissue coverage. METHODS: A retrospective chart review of 118 patients with open tibia fractures requiring soft-tissue reconstruction treated at a single level 1 trauma center was performed. Demographic data as well as flap type were collected. Union status was determined using modified Radiographic Union Scale in Tibia Fractures score greater than 11. RESULTS: Limb salvage was achieved in 90% of patients. The overall rate of nonunion was 33%. Flap type significantly affected time to union, with local fasciocutaneous and keystone flaps having significantly longer time to union [202 days (SD 120.3)] than all other flap groups ( P = 0.01). Free flaps had significantly shorter time to union than local flaps [115 days (SD 49.6) versus 149 days (SD 75.4); P = 0.02]. Muscle flaps had significantly shorter time to union than fasciocutaneous flaps [123 days (SD 52.4) versus 165 days (SD 104.1); P = 0.04]. This remained true after controlling for fracture location, patient age, need for second flap, and fixation method ( P = 0.037). Patients who underwent an initial soft-tissue reconstruction with a local muscle flap were more likely to require a second flap to achieve wound closure (OR, 3.7; P = 0.008) and needing a second flap significantly increased time to union [162 days (SD 95.9) versus 122 days (SD 51.9); P = 0.03]. CONCLUSION: Flap type affects time to union but not nonunion rate in open tibia fractures. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Distal Radioulnar Achilles Allograft Interposition Arthroplasty: Does It Solve the Problem of Persistent Pain?

PURPOSE: Pain and instability following distal ulnar resection for distal radioulnar joint (DRUJ) arthritis is a problem without a clear solution. We investigated the outcomes of DRUJ interposition arthroplasty for the management of symptomatic radioulnar convergence. METHODS: A retrospective review was performed for all patients who underwent Achilles tendon allograft interposition arthroplasty following the failure of distal ulna resection between October 2009 and January 2015. Records were reviewed for demographics, comorbidities, surgical history, pre- and postoperative pain, range of motion, grip strength, and complications. Radiographs and computed tomography scans were evaluated for distal radioulnar instability, distal ulnar absorption, ulnar scalloping, radioulnar convergence, and allograft subluxation. Reconstructive failure was defined as the presence of moderate-to-severe persistent distal radioulnar pain, instability with radiographic evidence of radioulnar convergence or allograft subluxation on radiographs or computed tomography scans, or the need for revision arthroplasty procedure. RESULTS: Ten patients met the inclusion criteria. The mean age was 49 ± 10 years. The average follow-up after interposition arthroplasty was 76 ± 23 months. The preoperative means of grip strength, arc of pronosupination, flexion, and extension were similar after surgery. The mean arc of pronosupination improved by 26.5°, and the wrist flexion-extension arc in patients without arthrodesis improved by 22.6°. The grip strength increased by 1.7 kg. Seven of 10 patients had continued symptoms of pain and instability related to symptomatic allograft subluxation and/or radioulnar convergence. Five patients underwent revision surgery; the mean time to revision was 26 months. CONCLUSIONS: Mid- to long-term follow-up of patients after salvage allograft interposition arthroplasty of the DRUJ resulted in minimal functional improvement in terms of arc of motion and grip strength. Persistent radioulnar pain was common, with half of the patients requiring revision operations following allograft interposition. Given this high failure rate, alternative procedures should be considered for the management of chronic pain and instability of the DRUJ. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Vascularized Bone Grafts in Orthopaedic Surgery: A Review of Options and Indications.

Vascularized bone grafts have demonstrated increased perfusion, structural integrity, and ability to achieve good outcomes in challenging clinical situations when compared with nonvascularized grafts. These grafts may be pedicled or free, and bring perfused, viable bone into areas of impaired healing. Although numerous grafts have been described, a few grafts have demonstrated particular usefulness and versatility. Pedicled grafts from the distal radius, medial femoral condyle, ribs, and fibula have improved outcomes in challenging situations without the need for microsurgery. Free grafts from the fibula and medial femoral condyle/trochlea, although they require microsurgical anastomosis, can be transferred to virtually any site in the body and have expanding indications. The capacity of these grafts to achieve favorable outcomes in difficult cases make them a powerful tool for orthopaedic surgeons to have in their armamentarium.

Motion and Strength Analysis of 2-Tine Staple and K-Wire Fixation in Scapholunate Ligament Stabilization in a Cadaver Model.

Purpose: Previous studies have demonstrated the benefits of 2- and 4-tine staple fixation in scapholunate interosseous ligament (SLIL) reconstruction, including improved rotational control and avoidance of the articular surface. This study compared scaphoid and lunate kinematics after SLIL fixation with traditional Kirschner wire (K-wire) fixation or 2-tine staple fixation. Methods: Eight fresh frozen cadaver arms with normal scapholunate (SL) intervals were included. Infrared motion capture was used to assess kinematics between the scaphoid and lunate as the wrists were moved through a simulated dart-throw motion. Kinematic data were recorded for each wrist in 4 states: SLIL intact, SLIL sectioned, K-wire fixation across SL interval and scaphocapitate joint, and 2-tine Nitinol staple fixation across SL interval. Strength of the SL staple fixation was evaluated using an axial load machine to assess load to failure of the staple construct. Results: Range of motion of the scaphoid and lunate with SLIL intact and SLIL sectioned were similar. K-wire fixation across the SL interval significantly decreased the overall wrist range of motion as well as scaphoid and lunate motion in all planes except for scaphoid flexion. Conversely, scaphoid and lunate motion after staple fixation was similar to that in normal wrists, except for a significant decrease in scaphoid extension. Under axial load simulating a ground-level fall, 3 of 8 arms demonstrated no failure, and none of the failures was due to direct failure of the 2-tine staple. Conclusions: This study demonstrates 2-tine staple fixation across the SL interval is effective in providing initial stability and maintaining physiologic motion of the scaphoid and lunate compared with K-wire fixation after SLIL injury. Clinical relevance: This study demonstrates an alternate technique for the stabilization of the SL interval in repair of acute SLIL injuries using 2-tine staple fixation, which maintains near physiologic motion of the scaphoid and lunate after SLIL injury.

Hand Surgeon Perspectives on Upper Extremity Allograft: A Survey of the American Society for Surgery of the Hand.

INTRODUCTION: Allograft tissue products have widespread applications across surgical specialties, but little data exist about surgeon attitudes toward the use of these products in the upper extremity. METHODS: Using a web-based survey, we sought to investigate the use of and feelings toward allograft products among hand surgeons. A short questionnaire was distributed to all active members of American Society for Surgery of the Hand as of October 2015 (N = 2,578). Demographic and practice setting information was collected. Additionally, questions concerning the use of human allograft tissue products of various types including bone, skin, and soft tissues were asked. RESULTS: Of 2,578 American Society for Surgery of the Hand members, 406 hand surgeons (15.8%) responded to the survey. A large majority (92%) reported having used allograft products in the upper extremity. Orthopedic-trained surgeons were more likely to have used bone and tendon allograft, whereas plastic and general surgery-trained surgeons were more likely to have used nerve and dermis allograft. Reduced donor site morbidity and complication rates were factors motivating surgeons to use allograft tissue. CONCLUSIONS: In spite of variation with respect to their use, allograft tissue products are popular and interest in new products, especially to improve flexor tendon pulley reconstruction, is high.

Digital Pulley Reconstruction Using Pulley Allografts: A Comparison With Traditional Tendon-Based Techniques.

BACKGROUND: The safety and feasibility of sterile, acellular pulley allografts in reconstruction has been previously demonstrated. Comparisons with tendon-based techniques for pulley reconstruction have not been reported. We hypothesized that the use of allograft pulleys would result in reduced procedural time and equivalent clinical outcomes as compared with traditional tendon-based reconstructive techniques. METHODS: All cases of pulley reconstruction using either allograft pulleys or tendon-based pulley reconstruction between November 2013 and November 2015 were reviewed. Patients who underwent concomitant procedures were excluded. Patient demographics, comorbidities, operative details (tourniquet and total operative times, number of pulleys repaired), postoperative complications (surgical site infection, reoperation, stiffness, and persistent pain), disability of the arm, shoulder and hand scores, and follow-up data were recorded. A P value of <0.05 was considered significant. RESULTS: Fifteen pulleys in 10 patients were reconstructed: 5 tendon-based and 5 with allograft. Average length of follow-up was 12.5 ± 2.9 months. There was no difference in patient demographic factors or comorbidities between groups. The most common indication for surgery was trauma. Four of 5 patients in the allograft group had multiple pulleys reconstructed versus 1 in the tendon-based group. One patient in the tendon-based group required reoperation versus 0 in the allograft group. Total operative and tourniquet times were significantly reduced in the allograft group (46 ± 5.5 vs 89 ± 12.9 minutes and 34 ± 6.8 vs 63 ± 5.3 minutes; P = 0.015 and 0.014). Postoperative disability of the arm, shoulder and hand scores were lower in the allograft group (56.8 vs 3.6, P = 0.11). There was no significant difference in postoperative range of motion between groups. CONCLUSION: Pulley reconstruction with allograft is an efficient, technically feasible, reconstructive technique that adheres to the principle of replacing like with like, while eliminating donor site morbidity. Overall operative and tourniquet times were significantly shorter using allograft pulleys for pulley reconstruction.

A Technique for Preoperative Estimation of Resection Weight in Vertical Reduction Mammoplasty Using 2 Breast-Specific Surface Measurements.

Insurance authorization of reduction mammoplasty can be a challenging process. Despite copious evidence of the benefits of this operation and evidence that specimen weight does not correlate with symptomatic relief, most insurance providers require estimated resection weights. Many formulas and techniques to predict resection weight are inconsistent or not specific to the vertical technique. This study describes a simple method for generating a surgeon-specific equation for accurately predicting vertical reduction mammoplasty resection weight using 2 breast surface measurements.

A Novel Small-Animal Model of Irradiated, Implant-Based Breast Reconstruction.

BACKGROUND: There is currently a need for a clinically relevant small-animal model for irradiated, implant-based breast reconstruction. Present models are inadequate in terms of suboptimal location of expander placement and mode of radiation delivery, correlating poorly with the human clinical scenario. The authors hypothesized that by delivering fractionated radiation and placing an expander under the scalp of the animal, they would achieve soft-tissue changes histologically analogous to those seen in human irradiated, implant-based breast reconstruction. METHODS: This study consisted of 11 immunocompetent, hairless rats divided into three groups as follows: untreated control (n = 3), tissue-expanded scalps (n = 4), and fractionated irradiation plus tissue expansion of the scalp (n = 4). At the completion of the experiment for each group, skin tissue samples were analyzed histologically for vascularity, epidermal and dermal thickness, and collagen fiber alignment or scar formation. RESULTS: Expanded rat epidermis was significantly thicker and dermis was more vascular than nonexpanded skin. The authors observed a greater degree of collagen fiber alignment in the expanded group compared with nonexpanded skin. The combination of irradiation and expansion resulted in significant dermal thinning, vascular depletion, and increased scar formation compared with expanded skin alone. CONCLUSIONS: The authors describe a novel small-animal model for irradiated, implant-based breast reconstruction where histologic analysis shows structural changes in the skin consistent with known effects of radiation therapy and expansion in human skin. This model represents a significant improvement from previous ones and, as such, holds the potential to be used to test new therapeutic agents to improve clinical outcomes.

Avoidance of Tracheostomy Using Mandibular Distraction in an Infant With Severe Condylar Dysplasia and Airway Obstruction.

Craniofacial microsomia (CFM) is a common craniofacial anomaly characterized by asymmetric malformation of the mandible, ear, and other structures including the upper airway. The degree of mandibular hypoplasia is classified using a scheme developed by Pruzansky and modified by Kaban. Severe condylar dysplasia is the hallmark of Pruzansky-Kaban types IIB and III. Distraction osteogenesis has emerged as a treatment modality for mandibular hypoplasia in this setting for the treatment of asymmetry and airway obstruction. However, its use to resolve upper airway obstruction and avoid tracheostomy in infants with types IIB and III is not reported in the literature. The authors present a patient with successful distraction osteogenesis in a patient with CFM resulting in a Pruzansky IIB micrognathia. The authors achieved resolution of upper airway obstruction and avoidance of tracheostomy.

A genomic map of viroid RNA motifs critical for replication and systemic trafficking.

RNA replication and systemic trafficking play significant roles in developmental regulation and host-pathogen interactions. Viroids are the simplest noncoding eukaryotic RNA pathogens and genetic units that are capable of autonomous replication and systemic trafficking and offer excellent models to investigate the role of RNA structures in these processes. Like other RNAs, the predicted secondary structure of a viroid RNA contains many loops and bulges flanked by double-stranded helices, the biological functions of which are mostly unknown. Using Potato spindle tuber viroid infection of Nicotiana benthamiana as the experimental system, we tested the hypothesis that these loops/bulges are functional motifs that regulate replication in single cells or trafficking in a plant. Through a genome-wide mutational analysis, we identified multiple loops/bulges essential or important for each of these biological processes. Our results led to a genomic map of viroid RNA motifs that mediate single-cell replication and systemic trafficking, respectively. This map provides a framework to enable high-throughput studies on the tertiary structures and functional mechanisms of RNA motifs that regulate viroid replication and trafficking. Our model and approach should also be valuable for comprehensive investigations of the replication and trafficking motifs in other RNAs.

Small RNAs in tomato fruit and leaf development.

Tomato fruit and leaf development offers excellent systems to study the evolution of gene regulation underlying development of different organs. We have identified over 350 and 700 small RNAs from tomato fruit and leaf, respectively. Except for conserved microRNAs, more than 90% of the small RNAs are unique to tomato. We confirmed expression of some conserved as well as novel putative microRNAs by Northern hybridization. Our results help form a basis for comparative studies on how small RNA-mediated gene expression has contributed to the evolution of common and distinct developmental pathways of fruits and leaves. We have established a website (http://ted.bti.cornell.edu/digital/sRNA/) for public access to all of our small RNA sequences, their expression patterns in respective tissues, and their matching genes or predicted target genes in a searchable manner.

WITHDRAWN: Small RNAs in tomato fruit and leaf development.

The Publisher regrets that this article is an accidental duplication of an article that has already been published in Biochem. Biophys. Acta, doi:10.1016/j.bbagrm.2007.09.003. The duplicate article has therefore been withdrawn.