Muscular Versus Non-Muscular Free Flaps for Soft Tissue Coverage of Chronic Tibial Osteomyelitis

In Vivo Engineering and Transplantation of Axially Vascularized and Epithelialized Flaps in Rats

The arteriovenous loop (AVL) model allows the in vivo engineering of axially vascularized flaps, the so-called AVL flaps. Although AVL flaps can be transplanted microsurgically to cover tissue defects, they lack an epithelial layer on the surface. Therefore, the objective of this study was to engineer axially vascularized AVL flaps with an accompanying epithelial layer for local defect reconstruction. In this study, AVLs were established in 20 male Lewis rats. Minimally invasive injection of keratinocytes onto the surface of the AVL flaps was performed on postoperative day (POD) 21. AVL flaps were explanted from 12 rats on POD 24 or POD 30, then the epithelium formed by the keratinocytes on the surface of the flaps was evaluated using immunofluorescence staining. In six other rats, the AVL flap was locally transposed to cover a critical defect in the rats' leg on POD 30 and explanted for analysis on POD 40. In two control rats, sodium chloride was applied instead of keratinocytes. These control flaps were also transplanted on POD 30 and explanted on POD 40. Our results revealed that 3 days after keratinocyte application, a loose single-layered epithelium was observed histologically on the AVL flaps surface, whereas after 9 days, a multilayered and structured epithelium had grown. The epithelium on the transplanted AVL flaps showed its physiological differentiation when being exposed to an air-liquid interface. Histologically, a layered epithelium identical to the rats' regular skin was formed. In the sodium chloride control group, no epithelium had been grown. This study clearly demonstrates that axially vascularized AVL flaps can be processed in the subcutaneous chamber by minimally invasive injection of keratinocytes. Thus, AVL flaps with an intact epithelial layer were engineered and could be successfully transplanted for local defect coverage in a small animal model.

[Current role of the latissimus dorsi flap in traumatology: Analysis of the activity of a plastic surgery department in a military hospital]

Reconstructive surgery's workhorse, the latissimus dorsi flap is increasingly abandoned in favour of fasciocutaneous flaps. The purpose of this study was to analyse the methods used to perform this flap and the evolution of its indications in order to define its current place in traumatology. Forty-four cases were recorded retrospectively from January 2000 to December 2020 at HIA Percy, including 37 cases of free flaps, mainly performed for reconstruction of extensive loss of substance with bone and/or joint exposure. It was also performed in 10.8% of cases for salvage after failure of an alternative reconstruction solution. This analysis confirms the value of the latissimus dorsi flap in cases of significant substance loss in the lower limb, but also in burn patients for functional rehabilitation or to allow early rehabilitation.

Covering of wound infection in hip arthroplasty with local cutaneous flaps

Total hip arthroplasty is a very common procedure to treat osteoarthritis. One of the complication is the infection which occurs in about 1% of the cases. The manifestation of infection can be poor wound healing with dehiscence and exposition of bone or prosthetic components. Hip arthroplasty infections are difficult to treat. It required an associated multidisciplinary approach with infectiology, orthopedic and plastic surgeries. The study included five patients with hip wound dehiscence after total hip arthroplasty. Coverage after orthopedic surgery was provided by local cutaneous flap. These cutaneous flaps were either a deep inferior epigastric perforator flap (DIEP) or a transposition flap. The orthopedic and the plastic treatment were done at the same time. Two deep inferior epigastric flaps were performed for patients with a deep defect with bone or prosthesis exposure. Four transposition flaps were done in three patients with wound dehiscence but without direct contact with the prosthesis. Three transposition flaps were done from the abdominal wall and one from the posterior thigh. The mean follow up was 18 months, ranging from 10 to 24months. After healing, there was no recurrence of the infection. In all cases, the coverage was obtained. The prosthesis was salvage and the gait was possible. Cutaneous flaps are easy and safe to cover the hip. They are reliable flaps even in patients with multiple co-morbidities. They do not cause sequelae on the recipient site. This study is the first about cutaneous flap for covering hip defects in hip arthroplasty infections.

Upscaled Skeletal Muscle Engineered Tissue with In Vivo Vascularization and Innervation Potential

Engineering functional tissues of clinically relevant size (in mm-scale) in vitro is still a challenge in tissue engineering due to low oxygen diffusion and lack of vascularization. To address these limitations, a perfusion bioreactor was used to generate contractile engineered muscles of a 3 mm-thickness and a 8 mm-diameter. This study aimed to upscale the process to 50 mm in diameter by combining murine skeletal myoblasts (SkMbs) with human adipose-derived stromal vascular fraction (SVF) cells, providing high neuro-vascular potential in vivo. SkMbs were cultured on a type-I-collagen scaffold with (co-culture) or without (monoculture) SVF. Large-scale muscle-like tissue showed an increase in the maturation index over time (49.18 ± 1.63% and 76.63 ± 1.22%, at 9 and 11 days, respectively) and a similar force of contraction in mono- (43.4 ± 2.28 µN) or co-cultured (47.6 ± 4.7 µN) tissues. Four weeks after implantation in subcutaneous pockets of nude rats, the vessel length density within the constructs was significantly higher in SVF co-cultured tissues (5.03 ± 0.29 mm/mm²) compared to monocultured tissues (3.68 ± 0.32 mm/mm²) (p < 0.005). Although no mature neuromuscular junctions were present, nerve-like structures were predominantly observed in the engineered tissues co-cultured with SVF cells. This study demonstrates that SVF cells can support both in vivo vascularization and innervation of contractile muscle-like tissues, making significant progress towards clinical translation.

How to measure success in lower extremity reconstruction, which outcome measurements do we use a systematic review and metanalysis

Different factors have to be considered and weighted in the treatment algorithm of lower extremity reconstruction. A combination of both clinicians' and patients' perspectives is necessary to provide a conclusive picture. Currently, there aren't any standardized and validated measurement data sets for lower extremity reconstructions. This makes it necessary to identify the relevant domains. We, therefore, performed a systematic review and metanalysis of outcome measurements and evaluated their ability to measure outcomes after lower extremity reconstruction. A systematic review and metanalysis according to the 'Preferred Reporting Items for Systematic Reviews and Meta-Analyses' protocol were performed for studies reporting at least one structured outcome measurement of lower extremity reconstruction. Both Patient (PROMs)- and Clinician reported outcome measurements (CROMs)were analyzed. Of the 2827 identified articles, 102 were included in the final analysis. In total 86 outcome measurements were identified, 34 CROMs, 44 PROMs and 8 (9.3%) outcome measurements that have elements of both. Twenty-four measure functional outcome, 3 pain, 10 sensations and proprioception, 9 quality of life, 8 satisfaction with the result, 5 measure the aesthetic outcome, 6 contours and flap stability and 21 contain multidomain elements. A multitude of different outcome measurements is currently used in lower extremity reconstruction So far, no consensus has been reached on what to measure and how. Validation and standardization of both PROMs and CROMs in plastic surgery is needed to improve the outcome of our patients, better meet their needs and expectations and eventually optimize extremity reconstruction by enabling a direct comparison of studies' results.

Patient-reported outcomes following free flap lower extremity reconstruction: A systematic review and meta-analysis

PURPOSE

Free flap reconstruction in the lower extremity has shown success for the management of large and complex defects, restoration of function, and favorable aesthetic outcomes. Patient-reported outcomes (PROs) have not been well explored in previous literature. This meta-analysis aimed to provide a comprehensive summary of PROs after free flap reconstruction in the lower extremity.

METHODS

We searched MEDLINE and Embase from 1946 to 2021 for studies reporting on PROs following free flap reconstruction in the lower extremity.

RESULTS

Overall, 53 studies were included, and 11 studies reported validated PRO measures for meta-analysis. A total of 1953 patients underwent reconstruction with 1958 free flaps for lower limb defects with a mean follow-up of 3.26 (0.25-7.83) months. The mean postoperative Lower Extremity Functional Scale (LEFS) scores were 60.3 (±12) out of 80 points (4 studies, 85 patients). The mean postoperative AOFAS scores were 75.1 (±15) out of 100 points (4 studies, 68 patients). The mean postoperative SF-36 scores were 88.1 (±8.0) out of 100 points; mental health component was 48.7 (±8.9), and physical component was 38.4 (±8.2), out of 50 points (4 studies, 88 patients).

CONCLUSION

Our findings demonstrated that patients report improved physical health, mental health, and function following lower extremity reconstruction with free flaps. Patients reported similar improvements in functional scores following lower extremity reconstruction regardless of their free flap type. Furthermore, patients with myocutaneous flaps may have improved mental health and worse physical health scores when compared to perforator flaps. The evidence profiles presented in this review indicate that additional research is needed to help guide future decision-making.

Muscle/musculocutaneous versus fasciocutaneous free flap reconstruction in the lower extremity: A systematic review and meta-analysis

BACKGROUND

Free flaps for soft tissue coverage of the lower extremity can be broadly divided into muscle/musculocutaneous and fasciocutaneous flaps. The purpose of this systematic review and meta-analysis was to assess their different post-operative outcomes.

METHODS

A systematic search was performed in PubMed, Scopus, and the Web of Science from their inception to February 2022. Non-randomized comparative studies, which describe any post-operative outcome of muscle/musculocutaneous and fasciocutaneous free flaps reconstruction in the lower extremity were included. Articles with duplicate titles, editorials, review articles, case series, case reports, and publications lacking an abstract, those reporting pediatric patients, those describing only muscle/musculocutaneous or fasciocutaneous free flaps, those with incomplete or incomparable post-operative outcomes, and studies involving <10 muscle/musculocutaneous or fasciocutaneous free flaps were excluded. A comparative meta-analysis was conducted on muscle/musculocutaneous and fasciocutaneous free flaps outcomes, comprising vascular thrombosis, partial or complete flap necrosis, infection, donor-site complications, non-union, and primary or recurrent osteomyelitis. The fixed-effects meta-analysis model was used when low heterogeneity (I²  < 50%) was identified.

RESULTS

Twenty-two articles with a total of 2711 flaps (1584 muscle/musculocutaneous flaps and 1127 fasciocutaneous flaps) were included in the qualitative and quantitative assessment. The rates of any flap necrosis (12.0% vs. 7.4%; p = 0.007) and donor-site complications (16.7% vs. 6.7%; p < 0.0001) were significantly higher for muscle/musculocutaneous flaps than for fasciocutaneous flaps. There were no significant differences in the rates of vascular thrombosis (10.5% vs. 10.7%; p = 0.98), complete flap necrosis (6.2% vs. 4.7%; p = 0.30), infection (19.4% vs. 14.7%; p = 0.18), non-union (18.9% vs. 14.8%; p = 0.33), and primary or recurrent osteomyelitis (14.7% vs. 12.4%; p = 0.69).

CONCLUSION

This meta-analysis revealed no significant difference in long-term post-operative outcomes, but suggested that fasciocutaneous flaps should be preferred to avoid flap necrosis and donor-site complications.

Veno-accompanying artery fasciocutaneous flaps following wide excision of soft tissue tumors in the lower legs

BACKGROUND

Soft tissue defects following wide excision of malignant soft tissue tumors (STTs) are sometimes too large for primary closure, especially in the lower legs where available soft tissue is limited. This study aimed to determine the clinical outcomes of reconstruction of a defect after wide excision of an STT with a veno-accompanying artery fasciocutaneous (VAF) flap in the lower leg.

METHODS

This study comprised 9 patients with malignant STTs who had undergone reconstructive surgeries using VAF flaps after wide excisions, between October 2010 and September 2017. We retrospectively reviewed and collected data involving age, sex, follow-up period, histological diagnosis, surgical procedures, size and location of defects, size and location of the flaps, venous source of the flaps, direction of the pedicles, closing of donor sites, perioperative chemotherapies, postoperative complications, and the presence of postoperative local recurrence and metastasis.

RESULTS

The median follow-up period was 91.5 (range, 15.5-189.0) months. Four patients had defects located around the knee, 3 patients had defects located on the calf, and 2 patients had defects located around the ankle. The mean flap size was 95.6 × 119.4 (range, 50 × 100-130 × 140) mm. Six patients had venous sources from the small saphenous vein and 3 patients had venous sources from the great saphenous vein. The pedicles were proximally based in 4 patients and distally based in 5 patients. All flaps remained viable without any complications.

CONCLUSIONS

Our findings showed that the VAF flap was easily elevated and reliable. Furthermore, it was effective in reconstructing soft tissue defects following wide excisions of STTs in the lower leg.

[A pedicled deep inferior epigastric flap to cover a hip arthroplasty infection]

The deep inferior epigastric perforator (DIEP) flap is a reliable flap mostly used in skin resurfacing after signifiant resection for sarcoma or correction contour deformities. This case is about a pedicled DIEP flap covering the trochanteric region after a total hip arthroplasty infection. A 62years old woman with a BMI at 42kg/m² presents an infected total hip arthroplasty with a cutaneous defect. The hip prosthesis is changed and covered with a pedicled DIEP flap. This original case reports the used of pedicled DIEP flap in hip coverage. This local fasciocutaneous flap covered the hip osteoarticular infection. The limb is salved and the patient can walked again. The success of this surgery is the collaboration between infectious disease specialist, orthopedic surgeon and plastic surgeon.

Addressing common orthopaedic calamities with microsurgical solutions

Reconstructive microsurgery has been an essential aspect of orthopaedic surgery and extremity reconstruction since the introduction of the operating microscope in the mid-20^th century. The reconstructive ladder ranges from simple healing by secondary intention to complex procedures such as free tissue transfer and vascularized composite allotransplantation. As orthopaedic surgery has evolved over the past 60 years, so too have the reconstructive microsurgical skills that are often needed to address common orthopaedic surgery problems. In this article, we will discuss a variety of complex orthopaedic surgery scenarios ranging from trauma to infection to tumor resection as well as the spectrum of microsurgical solutions that can aid in their management.

Factors affecting the outcome of lower extremity osteomyelitis treated with microvascular free flaps: an analysis of 65 patients

Background

Free flaps have been a useful modality in the management of lower extremity osteomyelitis particularly in limb salvage. This study aimed to determine the factors affecting the outcome of free flap reconstruction in the treatment of osteomyelitis.

Methods

This retrospective study assessed 65 osteomyelitis patients treated with free flap transfer from 2015 to 2020. The treatment outcomes were evaluated in terms of the flap survival rate, recurrence rate of osteomyelitis, and amputation rate. The correlation between outcomes and comorbidities, causes of osteomyelitis, and treatment modalities was analyzed. The following factors were considered: smoking, peripheral artery occlusive disease, renal disease, diabetic foot ulcer, flap types, using antibiotic beads, and negative pressure wound therapy.

Result

Among the 65 patients, 21 had a severe peripheral arterial occlusive disease. Osteomyelitis developed from diabetic foot ulcers in 28 patients. Total flap failure was noted in six patients, and osteomyelitis recurrence was noted in eight patients, for which two patients underwent amputation surgery during the follow-up period. Only end-stage renal disease had a significant correlation with the recurrence rate (odds ratio = 16.5, p = 0.011). There was no significant relationship between outcomes and the other factors.

Conclusion

This study showed that free flaps could be safely used for the treatment of osteomyelitis in patients with comorbidities and those who had osteomyelitis developing from diabetic foot ulcers. However, care should be taken in patients diagnosed with end-stage renal disease.

Multistep reconstruction of a post-traumatic defect in the lower limb with AV loop and free myocutaneous latissimus dorsi flap combined with a perforator monitor skin island after loss of ALT flap

Crush injuries of the lower extremity with extensive osseous and soft tissue damage impose a big challenge even for an interdisciplinary reconstructive approach. Multistep reconstruction with negative wound pressure therapy for soft tissue management and external fixation for osseous stability preceding free flap transfer leads to optimized outcome. We report the successful multistep reconstruction of a third-degree open right tibial fracture with extensive soft tissue defect with an arteriovenous loop preceding latissimus dorsi flap coverage with a perforator skin island after loss of an anterior lateral thigh (ALT) flap due to intima damage of the recipient vessels. The described method is a safe reconstructive concept after primary flap loss with persistent extensive tissue damage.

Superior epigastric artery perforator flap for reconstruction of deep sternal wound infection

BACKGROUND

The treatment of deep wound sternal infection requires loco-regional pedicled flaps, usually with muscular flaps. Perforator propeller flaps represent the ultimate progress in the history of reconstructive surgery. We report here our experience with the superior epigastric artery perforator (SEAP) flaps to repair sternal defect.

PATIENTS AND METHODS

Six patients presenting deep sternal wounds infection were treated with SEAP propeller flap, between March 2015 and June 2017. The mean age was 71.5 (range 53-83) years. The mean length and width of the defect were 16.2 × 7 cm (ranging 8-20 × 4-10). An elliptical skin flap pedicled on the SEAP was harvested in the inframammary fold and rotated up to 90° to cover the defect.

RESULTS

All SEAP flaps achieved a successful entire coverage of the defect. The mean size of the skin paddle of the flap was 20.2 × 7.3 cm (ranging 14-27 × 6-9). All flaps were able to provide a complete sternal wound cover. Venous congestion was present in five cases and adequately treated by leech therapy; necrosis was distal in one case, and interesting the entire superficial flap in two cases but with deep tissues remaining viable and able to cover the mediastinum: an infected flap required revision. Satisfyingly, at 2-years postoperative follow-up all-patients were alive with a successful mediastinal cover.

CONCLUSIONS

The SEAP Perforator propeller flap is an alternative to muscle flaps to achieve treatment of deep and large sternal wound infection.

A neglected problem in the utilization of free anterolateral thigh flap toward reconstructing complicated wounds of extremities: the obliteration of deep dead space

Background

Deep dead space may be thought as an independent risk factor of the poor infection control after flap reconstruction in complex limb wounds. But it can be easily neglected. The conventional skin flap and musculocutaneous flap are difficult to obliterate the deep dead space in irregular shape effectively. It was investigated that the clinical application of chimeric anterolateral thigh perforator flap in the treatment of complex wounds complicated with deep dead space of the extremities in the paper.

Methods

Fifty-six cases complicated with deep dead space wounds were registered in group. Following thorough debridement and treatment with VSD, the granulation tissues grew with well-controlled infection. And then the chimeric anterolateral thigh perforator flap was used to obliterate the deep dead space and repair the wounds. The postoperative flap survival and infection conditions were evaluated.

Results

Overall, the infection was effectively controlled, without persistent exudation or sinus tract formation after wound healing. While 5 cases lost to follow-up, the remaining 51 cases were followed up until 15 months on average. Generally, the affected extremities recovered satisfactorily with normal appearances and texture of the flaps, along with normal functions. Importantly, no recurrence of infection was observed.

Conclusion

During the grafting of chimeric perforator flap pedicled with lateral thigh muscle flap, the muscle flap is recommended to obliterate the deep dead space while the skin flap is being used to cover the wound. The combination of these two technologies performed well in the repair and reconstruction of the complex wounds of the extremities, possessing potential for broader clinical application.

The Distally Based Posterior Tibial Artery Flap

Soft tissue defects to the distal leg and hindfoot are challenging with only the smallest defects closed primarily without tissue transposition. These defects to the distal leg and hindfoot can lead to tendon desiccation, damaged neurovascular structures, and exposed joint surfaces. These wounds can be the result of postoperative dehiscence and exposed orthopedic hardware, with high susceptibility to infection. Pedicled fasciocutaneous flaps of the medial leg provide an excellent solution with good outcomes that do not require microanastomosis and have similar outcomes as compared with free flap reconstruction in the lower extremity.

Peroneal Artery Adipofascial Flaps for Coverage of Distal Leg and Rearfoot

Chronic wounds of the lower extremity can pose several obstacles for the treating physician as well as the patient. Peroneal artery adipofascial flaps have been shown to be a reliable and durable option for reconstruction of these defects for many reasons, including ease of dissection, minimized donor site mobility, reliability of take to underlying surfaces, and cosmetically more pleasing outcome. This article discusses the current literature regarding the use of peroneal artery adipofascial flaps and our surgical technique for harvest, transfer, and postoperative course for this versatile flap.

Free flap reconstruction of sarcoma defects in the setting of radiation: a ten-year experience

Neoadjuvant treatment and surgical resection for sarcoma patients can often leave devastating wounds necessitating soft-tissue coverage in the form of free flaps. There is still debate as to the optimal flap for reconstruction of defects in irradiated fields. We aim to describe our experiences with free fasciocutaneous and free muscle flaps for sarcoma reconstruction in the setting of radiation therapy. A retrospective chart review was conducted encompassing all patients requiring soft-tissue reconstruction secondary to sarcoma resection from January 2010 to June 2019. Patient characteristics, flap viability and post-operative healing outcomes were all recorded and examined. In total, 49 patients who underwent 51 free-flaps were identified. Of these, 30 flaps were fasciocutaneous, while 21 were muscle-based. Most patients received pre-operative radiotherapy (76.5%), although these rates were not different between groups of flap type, and had no significant association with post-operative outcomes. Complication rates (31.3%) and re-operative rates (21.6%) were also comparable between flap types. Diabetes mellitus was significantly associated with delayed wound healing (p < .016), while the presence of peripheral vascular disease had a significant association with post-operative infection (p < .006). This study shows that free fasciocutaneous and free muscle-based flaps are both viable options for soft-tissue reconstruction demanded by sarcoma resection, even in the setting of radiation. Peripheral vascular disease and diabetes mellitus may confer increased wound complications.

Selective and Continuous Transarterial Heparin Infusion: Postmicrosurgical Therapy of Lower Leg Reconstruction for Cases with Recipient Artery Damage

BACKGROUND

Microsurgical lower extremity reconstruction is challenging because of high incidence of vascular thrombosis compared to microsurgical head and neck reconstruction. The risk of vascular pedicle thrombosis increases, if patients have arterial sclerosis or intimal dissection at the recipient artery. We performed selective and continuous transarterial heparin infusion for postoperative anticoagulant therapy.

METHODS

Fifteen patients (10 men and 5 women; mean age of 55.1 years; range of 16-86 years) received lower leg reconstruction using free flap. Postoperatively, a catheter was inserted into the femoral artery during surgery. Heparin infusion was performed through the catheter as a postoperative therapy for patients who had a risk factor of vascular pedicle thrombosis. Until two days post-operation, heparin was started between 5,000 and 10,000 IU per day. In postoperative days 3 and 4, half of the initial dose of heparin was administered. In postoperative days 5 and 6, 25% of the initial dose of heparin was administered.

RESULTS

Recipient arteries were the posterior tibial (n=11), anterior tibial (n=2), lateral circumflex femoral (n=1), and medial sural (n=1) arteries. Thirteen of the 15 cases showed arterial sclerosis or intimal dissection at the recipient artery. There was no case of vascular thrombosis. Hematoma formation at flap recipient was observed in four cases. Their initial heparin dose was than 8.5±1.7 U/kg/h.

CONCLUSION

Continuous transarterial heparin infusion was an effective anticoagulant therapy for the patients who had received free tissue transfer to a lower extremity. The initial dose of heparin should not exceed 6.5 U/kg/h.

Soft Tissue Coverage for Defects around the Knee Joint

Soft tissue injuries around the knee present a challenge for providing a cover when there is loss of tissue. Various flaps comprising of skin and muscles around the joint have been described. Understanding the anatomical basis and the design of these flaps can aid in choosing the right flap for a given situation. A prompt cover of the defects aids in quicker healing and quicker rehabilitation of the patient.