Single-stage Reconstruction of Elbow Flexion Associated with Massive Soft-Tissue Defect Using the Latissimus Dorsi Muscle Bipolar Rotational Transfer

Reconstruction of elbow flexion after sarcoma excision by a unipolar pedicled latissimus dorsi flap

INTRODUCTION

The latissimus dorsi flap is widely used in plastic surgery for covering the upper limb but also for reconstruction the function of the elbow or shoulder. We describe a case of a sarcoma of the anterior compartment of the arm, the surgical removal then the covering and reconstruction of the elbow flexion. This case was carried out by a unipolar pedicled flap of the latissimus dorsi.

MATERIAL AND METHODS

Three steps were performed (excision, flap preparation and flap fixation). The functional results (muscle strength, MRC scale) and range of motion (ROM) were analyzed. We performed a small literature review to compare the results.

RESULTS

A complete excision (R0) was carried out with a good vitality of the latissimus dorsi flap. A rapid scarring was obtained, allowing an early start of adjuvant radiotherapy. Muscular strength was 33% less compared to preoperative, MRC scale was classified 4. ROM of the elbow was rated at -10/0/130. One year after the operation, the patient is still in remission.

CONCLUSION

Our functional results are comparable to those found in the literature. The muscle strength in our case appears to be superior, probably linked to a brachio-radialis muscle still functional. No difference in function has been found in the literature between a unipolar or a bipolar transfer of the latissimus dorsi. This case report confirms the reliable and effective nature of the latissimus dorsi flap. The use of this flap for reconstruction after sarcoma surgery has only few reports in the literature.

Decellularized Extracellular Matrix-Derived Hydrogels: a Powerful Class of Biomaterials for Skeletal Muscle Regenerative Engineering Applications

Purpose

The extracellular matrix (ECM) is a complicated milieu consisting of structural and functional molecules secreted by the resident cells that provides an optimal microenvironmental niche for enhanced cell adhesion, growth, differentiation, and tissue formation and maturation. For decades, ECM bio-scaffolds prepared from decellularized tissues have been used to promote skeletal muscle regeneration; however, it was recently discovered that these decellularized ECM (dECM) materials can be further processed into hydrogels, thus expanding the potential applications of dECM materials in skeletal muscle regenerative engineerisng (SMRE). This review article highlights the recent advances in dECM-derived hydrogels toward skeletal muscle regeneration and repair.

Method

We screened articles in PubMed and bibliographic search using a combination of keywords. Relevant and high-cited articles were chosen for inclusion in this narrative review.

Results

Here, we discuss the skeletal muscle ECM's structure, function, and biochemical composition with emphasis on the role of the ECM during skeletal muscle embryogenesis, growth, development, and repair. Furthermore, we review various hydrogels used to promote skeletal muscle regeneration. We also review the current applications of dECM-derived hydrogels toward SMRE. Finally, we discuss the clinical translation potential of dECM-derived hydrogels for skeletal muscle regeneration and repair and their potential clinical considerations in the future.

Conclusion

Although much progress has been made in the field of dECM-derived hydrogels toward SMRE, it is still in its nascent stage. We believe improving and standardizing the methods of decellularization, lowering the immunogenicity of dECMs, and carrying out in vivo investigations in large animal models would advance their future clinical applications.

Lay Summary

Researchers have discovered an effective way to turn tissue materials into jelly-like substances known as extracellular matrix (ECM)-derived hydrogels. These ECM-derived hydrogels can help muscles heal better after serious injuries. They can be injected into gaps or used to guide muscle growth in the lab or body. This review article explains how these ECM-derived hydrogels are made and how they can be used to improve muscle healing. It also discusses their possible use in clinics and what needs to be considered before using them for medical treatments.

Treatment strategies for soft tissue injuries associated with blunt brachial artery injury

INTRODUCTION

Blunt brachial artery injuries (BAI) require reconstruction with an extensive vein graft due to the wide area of arterial damage. In the upper arm, safe options for pedicle flaps are limited, and selecting recipient vessels for free-flap surgery is challenging, complicating the treatment of soft tissue injuries associated with blunt BAI. This study aimed to analyze the characteristics and soft tissue reconstruction of blunt BAI and propose treatment strategies for treating associated soft tissue injuries.

METHODS

Patients with blunt BAI who treated between August 2013 and April 2024 were included. Blunt BAI cases were classified into three groups (Type1A, Type1B, and Type2) based on soft tissue injury localization and elbow flexion reconstruction necessity. Patient demographics, treatment details, and treatment outcomes were investigated.

RESULTS

Seven patients were included to this study. There were two cases of Type1A, three Type1B, and two Type2. Three cases of Type1B underwent soft tissue reconstruction using pedicled latissimus dorsi flap and concurrent reconstruction of the elbow flexion. One case of Type2 was treated with free latissimus dorsi flap using AV loop, and the remaining case of Type2 was performed forearm amputation.

CONCLUSION

This study examined the treatment details of seven patients with blunt BAI. If a soft tissue injury is localized to the upper arm, it can be treated with a pedicle flap. However, if the damage extends beyond the forearm, a free flap is essential and some ingenuity is required to select the recipient blood vessel.

Biceps Transfer to FDP-FPL Tendon Augmented with Fascia Lata to Restore Hand Function in Neglected Fracture Treated by Traditional Bone-setters

Neglected bone fractures owing to the traditional bone-setter practices could lead to devastating complications. We aimed to describe the procedure and outcome of fascia lata augmentation for a forearm massive soft tissue loss case. Here, we report a case of a 14-year-old boy who presented to our hospital with a history of neglected right forearm fracture 4 years prior. He had been treated by a traditional bone-setter instead of seeking professional medical help, which resulted in wide-spread infection requiring debridement and, eventually, massive soft tissue loss, wrist radial deviation deformity due to epiphyseal growth arrest, and loss of all right-hand function. Intervention performed was biceps transfer to flexor digitorum profundus (FDP) and flexor pollicis longus (FPL) tendon augmented with fascia lata with anterior capsulectomy, bilobed flap, and transfixing wire of wrist joint, followed by ulnar centralization with wrist arthrodesis. The patient reported satisfaction postreconstruction, owing to the enhancement of hand function and appearance. He also showed significant improvement in activities of daily living and penmanship, and was even able to continue his old hobby as a traditional puppeteer. Autologous fascia lata tendon transfer connecting biceps to FDP and FPL tendon alongside ulnar centralization with wrist arthrodesis is a novel technique that has promising results to improve hand function and appearance.

Functional reconstruction of elbow flexion with latissimus dorsi muscle rotational transfer: two case reports

BACKGROUND

We report two cases of biceps brachii and brachialis paralysis due to musculocutaneous nerve injury in which elbow joint flexion was reconstructed using rotational transfer of the latissimus dorsi muscle with sutures to the radial and ulnar tuberosities, thereby enabling flexion by simultaneous activation of the humeroradial and humeroulnar joints. In cases of associated brachialis paralysis, weaker flexion strength can be expected when the forearm is in a pronated position than when it is in a supinated state. To the best of our knowledge, no previous study has reported the rotational position of the forearm during elbow joint flexion reconstruction.

CASE PRESENTATION

Case 1 involved a 30-year-old Asian male who presented with a rupture of the musculocutaneous, median, radial, and ulnar nerves. Reconstruction was performed by rotational transfer of the latissimus dorsi muscle. In this case, the supination and pronation flexion forces were equal. Case 2 involved a 50-year-old Asian man who presented with partial loss of the musculocutaneous nerve, biceps brachii, and pectoralis major due to debridement. Reconstruction was performed by rotational transfer of the latissimus dorsi muscle. In this case, supination and pronation flexion strengths were demonstrated to be equal. Our reconstruction method used the rotational transfer of the latissimus dorsi muscle; the distal muscle flap was divided into radial and ulnar sides to allow elbow joint flexion by simultaneously activating the humeroradial and humeroulnar joints. These sides were then fixed to the anchors at the radial and ulnar tuberosities. Finally, they were wrapped around the myotendinous junction of the biceps brachii or brachialis and secured using sutures.

CONCLUSIONS

Although larger studies are required to verify these methods, this case study successfully demonstrates the following: (1) the flexion strength in the supinated position was equal to that in the pronated position; (2) the stability of the humeroradial and humeroulnar joints was unaffected by the forearm's rotational position; and (3) a satisfactory range of motion of the elbow joint was obtained, with no complications.

Unipolar Latissimus Dorsi Transfer for Restoration of Elbow Flexion in Residual Post-traumatic Brachial Plexus Palsy Associated with Distal Humeral Fractures

Introduction  Elbow flexion is indispensable for both functioning and nonfunctioning hands. It is well perceived that restoration of elbow function is the first reconstructive priority in cases of brachial plexus injuries. The authors assessed the impact of associated distal humeral fractures on the functional outcome after unipolar latissimus dorsi transfer (ULDT) for restoration of elbow flexion in patients with residual brachial plexus palsy (BPP). Patients and Methods  Twenty-three patients operated for restoring elbow flexion after residual post-traumatic BPP (with or without distal humeral fracture) by unipolar latissimus dorsi transfer (ULDT) were reviewed for a retrospective study. Patients were divided into two groups; associated distal humeral fracture group (HF-group; 10 patients) and non-associated distal humeral fracture group (NHF-group; 13 patients). Elbow flexion active range of motion (AROM), flexion deformity in addition to Mayo Elbow Performance Score (MEPS) were assessed. Results  In both groups there were statistically better postoperative MEPS grading ( p  = 0.007, p  = 0.001 , respectively) and scoring with a mean of 81 ± 16.1 and 90 ± 4.6, respectively ( p < 0.001). The mean postoperative elbow flexion AROM was statistically better in both groups. The mean supination AROM was better in NHF group ( p  = 0.057). Conclusion  The use of ULDT in residual post-traumatic BPP is an efficient procedure in regaining functional flexion and supination. An associated distal humeral fracture does not significantly affect the final functional outcome. Level of Evidence  Level IV.

Successful Elbow Flexion Reconstruction Using Latissimus Dorsi Muscle Transfer Following a Road Traffic Accident and Upper Limb Trauma

BACKGROUND Several surgical procedures to restore elbow flexion have been reported in the literature. Multiple factors direct the selection of appropriate procedures for each patient, including hand dominance, neurovascular injury, and comorbidities. Traumatic damage to the anterior compartment of the arm is an indication for latissimus dorsi transfer, which can restore elbow flexion. Bipolar pedicled latissimus dorsi (LD) flap is a design used very rarely to simultaneously reconstruct biceps brachii soft-tissue defects and regain complete flexion function. We report the case of a 30-year-old man who underwent successful elbow flexion reconstruction using latissimus dorsi muscle transfer following a road traffic accident and upper limb trauma. CASE REPORT A 30-year-old man presented with acute compartment syndrome caused by a road traffic accident and impact trauma to the left arm. The surgical evaluation revealed proximal biceps tendons rapture; therefore, immediate repair and therapeutic fasciotomy were done. Subsequently, unsuccessful repair resulted in total necrosis of the biceps muscle, which necessitated debridement of the biceps muscle. Delayed reconstruction with an LD flap was successfully done after stabilization of the patient's condition. The flap was harvested as free-pedicled, then modified into a tube-like shape to resemble the biceps muscle. CONCLUSIONS This report has shown that the surgical procedure of latissimus dorsi muscle transfer can successfully restore elbow function following upper limb trauma; however, preoperative planning and postoperative follow-up are crucial for functional reconstruction of the upper extremity. In addition, carefully selecting reconstructive surgery considering patient factors, degree of injury, and the institution's capacity are essential factors in achieving optimal function restoration with minimal complications.

Mini review: Biomaterials in repair and regeneration of nerve in a volumetric muscle loss

Volumetric muscle loss (VML) following a severe trauma or injury is beyond the intrinsic regenerative capacity of muscle tissues, and hence interventional therapy is required. Extensive muscle loss concomitant with damage to neuromuscular components overwhelms the muscles' remarkable regenerative capacity. The loss of nervous and vascular tissue leads to further damage and atrophy, so a combined treatment for neuromuscular junction (NMJ) along with the volumetric muscle regeneration is important. There have been immense advances in the field of tissue engineering for skeletal muscle tissue and peripheral nerve regeneration, but very few address the interdependence of the tissues and the need for combined therapies to repair and regenerate fully functional muscle tissue. This review addresses the problem and presents an overview of the biomaterials that have been studied for tissue engineering of neuromuscular tissues associated with skeletal muscles.

Engineering skeletal muscle: Building complexity to achieve functionality

Volumetric muscle loss (VML) VML is defined as the loss of a critical mass of skeletal muscle that overwhelms the muscle's natural healing mechanisms, leaving patients with permanent functional deficits and deformity. The treatment of these defects is complex, as skeletal muscle is a composite structure that relies closely on the action of supporting tissues such as tendons, vasculature, nerves, and bone. The gold standard of treatment for VML injuries, an autologous muscle flap transfer, suffers from many shortcomings but nevertheless remains the best clinically available avenue to restore function. This review will consider the use of composite tissue engineered constructs, with multiple components that act together to replicate the function of an intact muscle, as an alternative to autologous muscle flaps. We will discuss recent advances in the field of tissue engineering that enable skeletal muscle constructs to more closely reproduce the functionality of an autologous muscle flap by incorporating vasculature, promoting innervation, and reconstructing the muscle-tendon boundary. Additionally, our understanding of the cellular composition of skeletal muscle has evolved to recognize the importance of a diverse variety of cell types in muscle regeneration, including fibro/adipogenic progenitors and immune cells like macrophages and regulatory T cells. We will address recent advances in our understanding of how these cell types interact with, and can be incorporated into, implanted tissue engineered constructs.

Versatility of the Pedicled Latissimus Dorsi Myocutaneous Flap in Reconstruction of Upper Limb and Trunk Soft Tissue Defects

Purpose The purpose of the study was to share our indications, technique, outcome, and complications associated with the pedicled latissimus dorsi myocutaneous flap (LDMF) for reconstructing various upper limb and trunk soft tissue defects. Patients and Methods We reviewed the prospectively collected data of the patients who underwent reconstruction of upper limb/trunk soft tissue defects with pedicled LDMF between January 2016 and March 2019. By analyzing the clinical scenarios, the location of flap inset, the arc of rotation, reach of the flap, and associated complications, we put forward few significant findings from our experience. Results Thirty-four patients were included in the study: 13 of them underwent LDMF for coverage of upper limb defects, 12 of them for postradical mastectomy soft tissue defects, 8 for posterior trunk reconstruction, and 1 for sternal wound infection. LDMF was successfully used to cover the scapula, anterior and posterior arms, axilla, cubital fossa, mid-forearm, breast, sternum, and midline dorsal wounds. When used reversely, the flap could cover the exposed spine in the midline dorsum. Three patients (9%) had major complications (two patients had partial flap necrosis which required additional debridement and skin grafting, and one patient required an additional transpositional flap). Three patients had minor complications (managed nonoperatively). Conclusion Pedicled LDMF is a straightforward and versatile option for reconstruction of the varied upper limb and trunk soft tissue defects with minimal complications. Level of Evidence This is a level IV, therapeutic, retrospective study.

Transplantation of insulin-like growth factor-1 laden scaffolds combined with exercise promotes neuroregeneration and angiogenesis in a preclinical muscle injury model

The regeneration of skeletal muscle can be permanently impaired by traumatic injuries, despite the high regenerative capacity of native muscle. An attractive therapeutic approach for treating severe muscle inuries is the implantation of off-the-shelf engineered biomimetic scaffolds into the site of tissue damage to enhance muscle regeneration. Anisotropic nanofibrillar scaffolds provide spatial patterning cues to create organized myofibers, and growth factors such as insulin-like growth factor-1 (IGF-1) are potent inducers of both muscle regeneration as well as angiogenesis. The aim of this study was to test the therapeutic efficacy of anisotropic IGF-1-releasing collagen scaffolds combined with voluntary exercise for the treatment of acute volumetric muscle loss, with a focus on histomorphological effects. To enhance the angiogenic and regenerative potential of injured murine skeletal muscle, IGF-1-laden nanofibrillar scaffolds with aligned topography were fabricated using a shear-mediated extrusion approach, followed by growth factor adsorption. Individual scaffolds released a cumulative total of 1244 ng ± 153 ng of IGF-1 over the course of 21 days in vitro. To test the bioactivity of IGF-1-releasing scaffolds, the myotube formation capacity of murine myoblasts was quantified. On IGF-1-releasing scaffolds seeded with myoblasts, the resulting myotubes formed were 1.5-fold longer in length and contained 2-fold greater nuclei per myotube, when compared to scaffolds without IGF-1. When implanted into the ablated murine tibialis anterior muscle, the IGF-1-laden scaffolds, in conjunction with voluntary wheel running, significantly increased the density of perfused microvessels by greater than 3-fold, in comparison to treatment with scaffolds without IGF-1. Enhanced myogenesis was also observed in animals treated with the IGF-1-laden scaffolds combined with exercise, compared to control scaffolds transplanted into mice that did not receive exercise. Furthermore, the abundance of mature neuromuscular junctions was greater by approximately 2-fold in muscles treated with IGF-1-laden scaffolds, when paired with exercise, in comparison to the same treatment without exercise. These findings demonstrate that voluntary exercise improves the regenerative effect of growth factor-laden scaffolds by augmenting neurovascular regeneration, and have important translational implications in the design of off-the-shelf therapeutics for the treatment of traumatic muscle injury.

Arm reconstruction

The arm is less often concerned by reconstructive surgeries than more distal parts of the upper extremity. However, when affected, the arm is frequently part of complex mutilating injuries involving composite defects. For a given traumatic or oncologic defect, there are several reconstructive options and choosing the right sequence may pose a challenge even to the most experienced surgeon. The latter must integrate not only functional and esthetic requirements, but also the surgeon's habits, especially in situations of emergency. Once life-threatening conditions are averted, wound debridement, bony stabilization, neurovascular, and cutaneous reconstruction tailored to the defects should be performed in a single-stage procedure. Functionally, prompt bony stabilization is necessary to allow early mobilization. Diaphyseal shortening of the humerus can be a salvage procedure to avoid nerve and vascular grafting, with good biomechanical tolerance up to 5cm. Restoration of adequate elbow motion sometimes requires muscle transfer and should be a main concern, as proper positioning of the hand during daily activities demands a functional elbow joint. Esthetically, the surgeon must choose the most cosmetic skin coverage option whilst limiting morbidity of the donor site area. The flaps vascularized by the sub- scapular or thoraco-dorsal vessels are the most useful flaps for arm reconstruction. This paper discusses the reconstructive sequence of complex defects of the arm and provides a review of commonly used reconstructive techniques supported with illustrative cases.

Elbow flexion reconstruction after arm-sparing excision for high-grade triton sarcoma: a case report

Background

Soft tissue sarcomas affecting the root of an upper extremity raise the question of limb amputation depending on their location, size, and malignancy. Malignant triton tumors are a rare subtype of neurofibrosarcomas that have been poorly reported in the literature. We report the case of a challenging reconstruction of the upper extremity using a pedicled latissimus dorsal flap.

Case presentation

A 25-year-old Occidental man was referred to our sarcoma unit for the management of a large, high-grade malignant peripheral nerve sheath tumor with no regional or distant extension and very fast progression. He was treated first by concomitant neoadjuvant radiotherapy and chemotherapy. Carcinologic excision was performed “en bloc” including the skin, the tumor, and the flexor muscles of our patient’s elbow. Coverage of the skin defect and elbow flexion restoration were achieved by using a homolateral pedicled musculocutaneous latissimus dorsi flap. Histological analysis showed an R0 resection. The reconstruction process recovered a complete bending of his elbow. He is still in remission at 26 months follow-up.

Conclusions

A malignant triton tumor is a rare, aggressive, and high-grade sarcoma. It was successfully treated and this case report describes an effective treatment modality. Reconstructive surgery, allowing large, complete tumor removal, is indispensable after neoadjuvant chemotherapy and radiotherapy.

Biomimetic Scaffolds in Skeletal Muscle Regeneration

Skeletal muscle tissue has inherent capacity for regeneration in response to minor injuries. However, in the case of severe trauma, tumor ablations, or in congenital muscle defects, these myopathies can cause irreversible loss of muscle mass and function, a condition referred to as volumetric muscle loss (VML). The natural muscle repair mechanisms are overwhelmed, prompting the search for new muscle regenerative strategies, such as using biomaterials that can provide regenerative signals to either transplanted or host muscle cells. Recent studies involve the use of suitable biomaterials which may be utilized as a template to guide tissue reorganization and ultimately provide optimum micro-environmental conditions to cells. These strategies range from approaches that utilize biomaterials alone to those that combine materials with exogenous growth factors, and ex vivo cultured cells. A number of scaffold materials have been used in the development of grafts to treat VML. In this brief review, we outline the natural skeletal regeneration process, available treatments used in the clinic for muscle injury and promising tissue bioengineering and regenerative approaches for muscle loss treatment.

Reconstruction of post-traumatic upper extremity soft tissue defects with pedicled flaps: An algorithmic approach to clinical decision making

PURPOSE

Pedicled flaps are still the workhorse flaps for reconstruction of upper limb soft tissue defects in many centers across the world. They are lifeboat options for coverage in vessel deplete wounds. In spite of their popularity existing algorithms are limited to a particular region of upper limb; a general algorithm involving entire upper limb which helps in clinical decision making is lacking. We attempt to propose one for the day to day clinical practice.

METHODS

A retrospective analysis of patients who underwent pedicled flaps for coverage of post-traumatic upper extremity (arm, elbow, forearm, wrist & hand) soft tissue defects within the period of January 2016 to October 2017 was performed. Patients were divided into groups according to the anatomical location of the defects. The flaps performed for different anatomical regions were enlisted. Demographic data and complications were recorded. An algorithm was proposed based on our experience, with a particular emphasis made to approach to clinical decision making.

RESULTS

Two hundred and twelve patients were included in the study. Mean age was 27.3 years (range: 1-80 years), 180 were male, and 32 were female. Overall flap success rate was 98%, the following complications were noted marginal flap necrosis requiring no additional procedure other than local wound care in 32 patients (15%), partial flap necrosis requiring flap advancement or extra flap in 15 patients (7%), surgical site infection in 11 patients (5%), flap dehiscence requiring re-suturing in 5 patients (2.4%), total flap necrosis 4 patients (2%).

CONCLUSION

The proposed algorithm allows a reliable and consistent method for addressing diverse soft tissue defects in the upper limb with high success rate.

Current Methods for Skeletal Muscle Tissue Repair and Regeneration

Skeletal muscle has the capacity of regeneration after injury. However, for large volumes of muscle loss, this regeneration needs interventional support. Consequently, muscle injury provides an ongoing reconstructive and regenerative challenge in clinical work. To promote muscle repair and regeneration, different strategies have been developed within the last century and especially during the last few decades, including surgical techniques, physical therapy, biomaterials, and muscular tissue engineering as well as cell therapy. Still, there is a great need to develop new methods and materials, which promote skeletal muscle repair and functional regeneration. In this review, we give a comprehensive overview over the epidemiology of muscle tissue loss, highlight current strategies in clinical treatment, and discuss novel methods for muscle regeneration and challenges for their future clinical translation.