Flap Tip Research Articles

Trapezius Muscle Flap for Posterior Neck and Shoulder Defects Following Malignant Tumor Resection-A Case Series from a Tertiary Cancer Facility.

Reconstructing defects of the shoulder and posterior scalp, arising following tumor resection, requires careful consideration of available options. While free tissue transfers and local advancement flaps have their established roles, the trapezius muscle flap offers a unique set of advantages like proximity, versatility, and reliability as it has a robust blood supply and relatively straightforward surgical technique. In this retrospective analysis, demographic and disease profiles of 10 patients with posterior scalp and shoulder defects following tumor resection, which were reconstructed with a trapezius flap between November 2020 and November 2023, were studied. Complications and functional outcomes were analyzed. Ten patients (9 men and 1 woman) were reconstructed using a trapezius flap. The mean age of the study sample was 45.3 years (30-60 years). Two patients developed donor site seroma and one of them developed wound dehiscence; one patient had partial necrosis of the flap tip, all managed conservatively, and one patient had tumor recurrence. However, the long-term result was good in all patients except the one with recurrence. The post-excision defects in the shoulder and posterior scalp were of mean size 13 ± 2 × 6 ± 2 cm, and the donor site morbidity analyzed by using VAS (visual analog scale) had a mean score of less than 3. This case series provides valuable insights into the successful use of the trapezius muscle flap for shoulder and posterior scalp defects following malignant tumor resection. The documented complications are minimal in comparison to the overall positive outcomes, making the trapezius muscle flap a viable and reliable option for reconstruction in this specific clinical scenario. However, further research is required to improve the design of the flap for different types of defects, refine surgical techniques, and compare outcomes with other reconstruction methods.

Modified gluteus maximus transfer for hip abductor deficiency

Transfer of the gluteus maximus with refixation at the greater trochanter for treatment of abductor deficiency. Symptomatic abductor deficiency with atrophy and fatty degeneration of the gluteal muscles > 50% (grade3 by quartile) with good strength of the gluteus maximus. Low atrophy or fatty degeneration of less than 50% of the gluteal muscles, limited strength of the gluteus maximus, infection. First, the fascia lata is incised dorsally to the tensor fascia latae muscle, with the incision extending approximately 1.5 cm proximal to the iliac crest. Asecond incision divides the gluteus maximus muscle longitudinally along the muscle fibers and continues towards the fascia lata distal to the greater trochanter. These incisions result in atriangular muscle flap, which is elevated and divided into anterior and posterior portions. The posterior flap is positioned ventrally over the femoral neck and fixed to the anterior capsule and the anterior edge of the greater trochanter. The anterior flap is placed directly on the proximal femur. For this purpose, agroove is prepared in the area of the proximal femur using aspherical burr to freshen up the future footprint. The anterior flap is positioned from the tip of the greater trochanter towards the insertion of the vastus lateralis muscle. Subsequently, the anterior flap is fixed to the created groove with transosseous sutures and positioned under the elevated vastus lateralis muscle in 15° abduction of the leg. To provide additional stabilization to the tendinous part of the anterior flap, ascrew is inserted distally to the greater trochanter. The vastus lateralis muscle is attached to the distal tip of the anterior flap, and the remaining gluteus maximus muscle is sutured to the fascia lata to cover the anterior flap. Additionally, aflap of the tensor fascia latae muscle can be mobilized and adapted to the reconstruction. Layered wound closure is performed. The technique of agluteus maximus transfer represents amethod for the treatment of chronic abductor deficiencies and improves abduction function as well as the gait pattern in short-term follow-ups. Fifteen patients (mean age at time of surgery 62years) had after amean follow-up of 2.5years. The modified Harris Hip Score (mHHS) improved from 48points preoperatively to 60points at follow-up. Preoperatively, 100% had apositive Trendelenburg sign; at follow-up, this was about 50%.

Unveiling a Hidden Pocket in HIV-1 Protease: New Insights Into Retroviral Protease Cantilever-Tip Region Characteristics.

The HIV-1 protease is critical for the process of viral maturation and as such, it is one of the most well characterized proteins in the Protein Data Bank. There is some evidence to suggest that the HIV-1 protease is capable of accommodating small molecule fragments at several locations on its surface outside of the active site. However, some pockets on the surface of proteins remain unformed in the apo structure and are termed "cryptic sites." To date, no cryptic sites have been identified in the structure of HIV-1 protease. Here, we characterize a novel cryptic cantilever pocket on the surface of the HIV-1 protease through mixed-solvent molecular dynamics simulations using several probes. Interestingly, we noted that several homologous retroviral proteases exhibit evolutionarily conserved dynamics in the cantilever region and possess a conserved pocket in the cantilever region. Immobilization of the cantilever region of the HIV-1 protease via disulfide cross-linking resulted in curling-in of the flap tips and the propensity for the protease to adopt a semi-open flap conformation. Structure-based analysis and fragment-based screening of the cryptic cantilever pocket suggested that the pocket may be capable of accommodating ligand structures. Furthermore, molecular dynamics simulations of a top scoring fragment bound to the cryptic pocket illustrated altered flap dynamics of the fragment-bound enzyme. Together, these results suggest that the mobility of the cantilever region plays a key role in the global dynamics of retroviral proteases. Therefore, the cryptic cantilever pocket of the HIV-1 protease may represent an interesting target for future in vitro studies.

Coverage of complex pararectal pelvic defects: role of the free myocutaneous musculus vastus lateralis flap

In the event of an advanced rectal carcinoma, an evisceration with rectal amputation may become necessary. The resulting defects, due to their extent, depth, or local tissue damage from previous surgeries and radiation, can in many cases only be closed through free microvascular tissue transfer. In this case series, we demonstrate the successful combination of a musculocutaneous musculus vastus lateralis flap (MVL) with a direct connection to the superior gluteal artery. Over a 47-month period, we retrospectively examined 11 cases of patients with dorsal pelvic defects after evisceration and rectal amputation that could not be closed using local or regional means. In cases of extensive defects with deep pararectal wound cavities, all these patients underwent defect coverage through a free myocutaneous MVL flap with a direct vascular anastomosis to the superior gluteal vessels. The mean defect size was 290.0 cm² (SD: 131.2; range: 200-600 cm²). The mean defect depth was 10.5 cm, necessitating MVL flap reconstruction with an average size of 336.3 cm². Three operative revisions were required due to postoperative bleeding. There were no arterial or venous thromboses, and no flap loss occurred. Only one necrosis of a distal flap tip was observed, which could be corrected secondarily by direct suturing. The case-mix evaluation yielded an average value of 24.251 (SD: 21.699; range: 7.036-65.748) points, emphasizing the complexity of the cases. Our results indicate that a free microvascular MVL flap is a viable therapeutic option for pararectal defects that cannot be closed by local or regional methods. The superior gluteal artery proves to be a safe and sufficient vascular connection. In combination, even extensive defects can be successfully closed.

Mechanism of drug resistance in HIV-1 protease subtype C in the presence of Atazanavir

AIDS is one of the deadliest diseases in the history of humankind caused by HIV. Despite the technological development, curtailing the viral infection inside human host still remains a challenge. Therapies such as HAART uses a combination of drugs to inhibit the viral activity. One of the important targets includes HIV protease and inhibiting its activity will minimize the production of mature structural proteins. However, the genetic diversity and the occurrence of drug resistant mutations adds complexity to effective drug design. In this study, we aimed at understanding the drug binding mechanism of one such subtype, namely subtype C and its insertion variant L38HL. We performed multiple molecular dynamics simulations along with binding free energy analysis of wild-type and L38HL bound to Atazanavir (ATV). From the analysis, we revealed that the insertion alters the hydrogen bond and hydrophobic interaction networks. The alterations in the interaction networks increase flexibility at the hinge-fulcrum interface. Further, the effects of these changes affect flap tip curling. Moreover, the changes in the hinge-fulcrum-cantilever interface alters the concerted motion of the functional regions leading to change in the direction of flap movement thus causing a subtle change in the active site volume. Additionally, formation of intramolecular hydrogen bonds in the ATV docked to L38HL restricted the movement of R1 and R2 groups thereby altering the interactions. Overall, the changes in the flexibility of flap together with the changes in the active site volume and compactness of the ligand provide insights for increased binding affinity of ATV with L38HL.

The Pedicled Anterolateral Thigh Flap as a Versatile Option for Resurfacing Extensive Lower Trunk Defects.

The resurfacing of large abdominal and perineal defects is a major concern, and it poses a great challenge to the reconstructive surgeon. The main target in the reconstruction of the abdomen is to ensure a stable soft-tissue cover, and a strong and reliable fascia to prevent hernia recurrence and fecal contamination. The pedicled anterolateral thigh flap (ALT) either in the myocutaneous or fasciocutaneous form is a work-horse for the closure of abdominal and perineal defects. There is a paucity of studies on the use of the anterolateral thigh flap among black Africans especially in Nigeria; hence, we present our experience with the use of this flap for extensive abdominal and perineal defects. The folders of all patients who had pedicled anterolateral thigh flap between January 2019 and July 2022 in our institution were reviewed. The patients' demographic data and the available details about the flap reconstruction were extracted from the folders. There were three males and two females, and the age range was between 22 and 48 years. Four cases resulted from tumor extirpation, while one was following extensive necrotizing fasciitis of the lower anterior abdominal wall. No gross anatomical variations were encountered intraoperatively. Four flaps had full survival, while one had marginal flap tip loss. The pedicled anterolateral thigh flap is an excellent reconstructive tool for the coverage of extensive abdominal and perineal defects.

Improvement of vertical axis wind turbine performance by using the optimized adaptive flap by the Taguchi method

ABSTRACT In light of the growing use of Vertical Axis Wind Turbines (VAWTs) in urban settings, research is increasingly focusing on passive control methods to enhance VAWT efficiency. This study aims to refine VAWT performance by optimizing an advanced turbine design equipped with an adaptive flap on the blade, focus on the power coefficient (CP). Using the Taguchi method, the optimization incorporated five control factors: flap position (ld), flap length (lf), flap angle (θ), flap tip length (lt), and angle of the flap tip length (αtip). The study employed an L16 (54) orthogonal array design. At a 2.62 tip speed ratio (TSR), all models underwent computational fluid dynamics (CFD) simulation. The influence of each factor was assessed using the ANOVA (Analysis of variance), and CP predictions were made based on these factors through Regression Analysis (RA). The results revealed optimal configurations of ld = 0.65c, lf = 0.15c, θ = 70°, lt = 0.06c, and αtip = 8, leading to a CP 74.01% greater than a conventional VAWT. ANOVA ranked factor contributions as: ld > lt > θ > lf > αtip, with ld contributing 39.58% and αtip only 1.34%. Predictions from the RA aligned well with the numerical findings. In conclusion, the adaptive flap design enhances performance by expanding the wake and amplifying the vortices behind the turbine blade.

Simplified and modified Limberg flap plus vacuum-assisted closure for treatment of sacrococcygeal pilonidal sinus disease.

Pilonidal sinus disease (PSD), a chronic inflammatory disease, affects the sacrococcygeal soft tissue, especially in young adults. The ideal treatment for PSD remains divergence. This study evaluated the application of a simplified modified Limberg flap combined with vacuum-assisted closure for treating PSD. This prospective study was conducted from 1 June 2017 to 31 March 2022 in Changhai Hospital, Naval Military Medical University, Shanghai, China. The study included 88 male patients (91.7%) and 8 female patients (8.3%). The 96 patients ranged in age from 15 to 34 years (mean ± SD, 23 ± 4.4). Under general anaesthesia, all patients underwent simplified modified Limberg flap reconstruction with vacuum-assisted closure. The patient's weight, surgical time, extubation time, hospital stay, time to return to normal life or work, wound infection, wound dehiscence and recurrence rate were recorded. The visual analogue scale (VAS) score and the Vancouver scar score were used to score patients' pain and scars in the surgical area. The volume of resected diseased tissue was 13.5-120 (mean ± SD, 34.993 ± 24.406) cm2 . The average surgical time during the treatment period was 97.68 ± 18.72 min, and the average extubation time was (6.36 ± 1.55) days, the mean hospital stay was 19.4 days; no patients were lost to follow-up. None of the patients experienced post-operative recurrence, wound infection, seroma or hematoma. Six patients (6.3%) experienced wound dehiscence at the flap tip around the natal cleft. The mean time to the resumption of daily activities was 26.3 days. The average VAS pain score was (6.00 ± 1.53) points, and the average Vancouver scar score was (5.96 ± 1.51) points, 12 patients (12.5%) were dissatisfied with their aesthetic results, and the average beauty satisfaction score is (6.64 ± 1.28) points. Simplified modified Limberg flap reconstruction with vacuum-assisted closure surgery is an effective and innovative method for the treatment of PSD, with a low recurrence rate and rapid recovery.

Perforator flap for burn reconstruction

BackgroundMajority of burn patients in Bangladesh are treated at home and tend to develop scar and scar contracture. Other than physical limitations there are also stigmatization, loss of marriageability or divorce particularly for women. Skin grafts are prone to contraction and need prolonged splintage and physiotherapy. Flaps are often too bulky. Local flaps have the advantage of increased positional comfort as compared to distant flaps like the abdominal or the groin flaps. Free flaps are technically demanding and facilities are not universally available. Advances in knowledge of blood supply of the skin have increased the potentials for perforator based skin flaps. MethodologyA total of 72 patients who could complete a minimum one year follow up were included in the study. All flaps were rotated around the axis of the perforator ranging from 90 degrees to 180 degrees. Skin pedicles were kept when possible, complete island flaps were designed when rotation was maximum. ResultsAmong the 72 cases 54 cases were electric burn wounds and18 were post burn scar contracture, 59 were male and 13 were female. 44 cases were done on leg. Smallest flap was 5 cm in length and the largest was 16 cm. Immediate complications include total flap loss, tip loss, margin loss, wound infection and hematoma under the flap was noted. In one case emergency exploration was required to control hemorrhage. Contour defect, dependent edema in legs, sensorineural deficit, limitation of joint movement was also observed. ConclusionA single perforator may safely supply its proper angiosome and up to the half of vascular territory of the adjacent perforator. This possibility is favored by vascular adoption directed toward the periphery that occurs by means of increased vascular pressure in the perforator artery after ligature of collateral subcutaneous and intramuscular arterial branches. The authors percept is, usually perforation is along the intermuscular septum, the portion of the flap that crosses beyond the adjacent intermuscular septum are at risk. Not required to go that far as residual wounds can be grafted with split thickness skin.

Oxygen saturation mapping during reconstructive surgery of human forehead flaps with hyperspectral imaging and spectral unmixing

BackgroundOptical spectroscopy is commonly used clinically to monitor oxygen saturation in tissue. The most commonly employed technique is pulse oximetry, which provides a point measurement of the arterial oxygen saturation and is commonly used for monitoring systemic hemodynamics, e.g. during anesthesia. Hyperspectral imaging (HSI) is an emerging technology that enables spatially resolved mapping of oxygen saturation in tissue (sO2), but needs to be further developed before implemented in clinical practice. The aim of this study is to demonstrate the applicability of HSI for mapping the sO2 in reconstructive surgery and demonstrate how spectral analysis can be used to obtain clinically relevant sO2 values. MethodsSpatial scanning HSI was performed on cutaneous forehead flaps, raised as part of a direct brow lift, in eight patients. Pixel-by-pixel spectral analysis, accounting for the absorption from multiple chromophores, was performed and compared to previous analysis techniques to assess sO2. ResultsSpectral unmixing using a broad spectral range, and accounting for the absorption of melanin, fat, collagen, and water, provided a more clinically relevant estimate of sO2 than conventional techniques, where typically only spectral features associated with absorption of oxygenated (HbO2) and deoxygenated (HbR) hemoglobin are considered. We demonstrate its clinical applicability by generating sO2 maps of partially excised forehead flaps showed a gradual decrease in sO2 along the length of the flap from 95 % at the flap base to 85 % at the flap tip. After being fully excised, sO2 in the entire flap decreased to 50 % within a few minutes. ConclusionsThe results demonstrate the capability of sO2 mapping in reconstructive surgery in patients using HSI. Spectral unmixing, accounting for multiple chromophores, provides sO2 values that are in accordance with physiological expectations in patients with normal functioning microvascularization. Our results suggest that HSI methods that yield reliable spectra are to be preferred, so that the analysis can produce results that are of clinical relevance.

A stomaplasty for total laryngectomy with a previous tracheostomy

ObjectiveStomaplasties were widely used to prevent or revise stomal stenosis, however, a previous tracheostomy can limit the choice of some techniques. This study aims to deal with this condition through a novel and simple technique called “Collar stomaplasty”. MethodsThis study involved 43 patients submitted for laryngectomy between 2017 and 2020. A tracheostomy 6–31 days prior to laryngectomy was performed in all cases. The collar stomaplasty, shaping the previous tracheostomy and surrounding skin, included 17 cases and the traditional X-shaped stomaplasty included 26 cases. Fisher's exact test was applied in an intergroup comparison of complications. ResultsOne out of the collar stomaplasty group demonstrated perioperative stomal infection and avascular necrosis (5.9%). Another developed stomal stenosis (5.9%). In the X-shaped stomaplasty group, necrosis at the tip of the tracheal flap occurred in 14 cases (53.8%), and stomal stenosis occurred in 5 cases (19.2%). A statistically significance occurred in stomal necrosis (p<0.05) while no statistically difference is observed in stomal stenosis (p>0.05) between these two groups. ConclusionsThe collar stomaplasty technique creates a laryngectomy tracheostoma by remodeling a previous tracheostomy. A wide and stable stoma, which facilitates stomal care, can be accomplished by this simple technique.

Comparison of single-stage reverse sural artery flap versus two-staged interpolated flap in distal lower limb injuries

&lt;p&gt;&lt;strong&gt;Background and Objective&lt;/strong&gt;: Plastic surgeons face challenging conditions when dealing with soft tissue injuries or defects involving the lower part of the leg and the proximal part of the foot. The objective of the current study is to compare single-staged reverse sural artery flaps with two-staged interpolated flaps in distal lower limb injuries.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Methods&lt;/strong&gt;: It was a prospective study carried out at the Department of Plastic Surgery, Allama Iqbal Memorial Teaching Hospital, Sialkot, Pakistan, over 5 years from 2015 to 2020. Sixty-eight (n = 68) patients with distal lower limb soft-tissue defects were enrolled and randomly allotted a two-stage interpolated flap design (group A) or single-stage reverse sural artery flap design (group B). The measured outcomes included the frequency of flap-tip necrosis, epidermolysis, partial or total flap loss, and additional procedures needed for managing these complications.&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Results&lt;/strong&gt;: Out of all the patients, 72% were of male gender and 28% were females with a mean age of 38.38 &amp;plusmn; 10.76 years. In group A, there were 6% of the cases where tip necrosis was the only impediment as compared to 17% in group B. In patients of group A, epidermolysis was seen in 12% as compared to 35% in group B whereas only 6% of patients in group A required secondary procedures for flap tip necrosis as compared to group B (47%). Paired t-test was used to calculate the statistical significance of the outcome between the two groups (p-value of 0.0491).&lt;/p&gt;&#x0D; &lt;p&gt;&lt;strong&gt;Conclusion&lt;/strong&gt;: The two-staged interpolated flap procedure results in fewer complications as compared to a single-staged reverse sural artery flap procedure. However, the shorter hospital stay in single-staged flap design is satisfying for the patients who did not report any complications with this procedure.&lt;/p&gt;

Mathematical analysis in the design of digital artery-based V–Y advancement flap in treating proximal interphalangeal joint flexion contracture

BackgroundThe digital artery-based V–Y advancement flap is a widely used flap for soft tissue coverage in the treatment of flexion contracture of the proximal interphalangeal (PIP) joint. A standard method for the flap design and a mathematical method to predict the advance distance have not been well established. In this study, we proposed a simplified method for the design of V–Y advancement flaps based on digital arteries and used a geometric model to predict the advance distance for the flexion contracture correction surgery.MethodsAccording to the general concept of hand flap design and law of cosine, we proposed three principles in the design of the digital artery-based V–Y advancement flap that should be followed. Since 2021 to 2022, finger geometric data of 120 fingers (index, middle, ring, and small fingers) from 30 healthy participants were collected and analysed to evaluate the necessary advance distance and flap tip angle for PIP flexion contracture correction of different fingers by our flap design method.ResultsThe middle finger needed a significantly longer advance distance compared to other fingers in the same degree flexion contracture correction. The ring finger had the largest length-to width ratio and smallest flap tip angle among the four fingers in the V–Y flap design. No vertical scar crossed the flexion creases and flap tip angle < 20° was found in the tentative V–Y flap design for the 120 fingers.ConclusionsOur flap design method provides a proper advance distance and flap length-to-width ratio without common skin complications in the flap design for PIP flexion contracture of index, middle, ring and small fingers. This geometric model provides a mathematical basis for prediction of advance distance and flap tip angle in the design of a digital artery-based V–Y advancement flap.

Inferiorly based nasolabial flap for reconstruction of full-thickness medium-sized lower lip and commissural defects following ablative cancer surgery.

Information regarding the design and usage of inferiorly based nasolabial flap for lower lip and commissural defect reconstruction following ablative cancer surgery remains limited. This study aimed to provide our design and experiences for such reconstructive purpose. Patients with lower lip or oral commissural cancer who received curative surgery involving reconstruction with inferiorly based nasolabial flap were included. The demographic data and clinical outcomes of these patients were obtained by retrospective chart review. A total of eight patients were enrolled in this study. All patients received ablative surgery at the National Cheng Kung University Hospital during May 2019 to May 2021, with their surgical defects reconstructed with unilateral inferiorly based nasolabial flap successfully. Among the five patients with lower lip cancer, one had a limited area of necrosis at flap tip. Another patient had a small orocutaneous fistula that healed spontaneously. No trismus or oral incompetence was noted following recovery. For the three patients with commissural cancer, a second stage commisuroplasy was needed after primary reconstruction. One patient had limited wound dehiscence at mouth angle following surgery, resulting in mild oral incompetence. Although mild trismus was noted in these three commissural cancer patients, all patients resumed normal diet during follow-up. Inferiorly based nasolabial flap is an excellent local flap for lower lip reconstruction following cancer ablative surgery. It is also a viable option for reconstruction of oral commissural defects. Minimal donor side morbidity, good functional recovery, and esthetic outcomes can be achieved with meticulous flap design.

Reconstructive surgery for treating pressure ulcers.

There are several possible interventions for managing pressure ulcers (sometimes referred to as pressure injuries), ranging from pressure-relieving measures, such as repositioning, to reconstructive surgery. The surgical approach is usually reserved for recalcitrant wounds (where the healing process has stalled, or the wound is not responding to treatment) or wounds with full-thickness skin loss and exposure of deeper structures such as muscle fascia or bone. Reconstructive surgery commonly involves wound debridement followed by filling the wound with new tissue. Whilst this is an accepted means of ulcer management, the benefits and harms of different surgical approaches, compared with each other or with non-surgical treatments, are unclear. This is an update of a Cochrane Review published in 2016. To assess the effects of different types of reconstructive surgery for treating pressure ulcers (category/stage II or above), compared with no surgery or alternative reconstructive surgical approaches, in any care setting. We used standard, extensive Cochrane search methods. The latest search date was January 2022. Published or unpublished randomised controlled trials (RCTs) that assessed reconstructive surgery in the treatment of pressure ulcers. Two review authors independently selected the studies, extracted study data, assessed the risk of bias and undertook GRADE assessments. We would have involved a third review author in case of disagreement. We identified one RCT conducted in a hospital setting in the USA. It enrolled 20 participants aged between 20 and 70 years with stage IV ischial or sacral pressure ulcers (involving full-thickness skin and tissue loss). The study compared two reconstructive techniques for stage IV pressure ulcers: conventional flap surgery and cone of pressure flap surgery, in which a large portion of the flap tip is de-epithelialised and deeply inset to obliterate dead space. There were no clear data for any of our outcomes, although we extracted some information on complete wound healing, wound dehiscence, pressure ulcer recurrence and wound infection. We graded the evidence for these outcomes as very low-certainty. The study provided no data for any other outcomes. Currently there is very little randomised evidence on the role of reconstructive surgery in pressure ulcer management, although it is considered a priority area. More rigorous and robust research is needed to explore this intervention.

Z-Plasty with Skin Grafting for Post-Burn Contracture - Study of 30 Cases

Introduction: Postburn contracture is a very common problem in case of undertreated and neglected cases of burns involving the flexor surface of joints of limbs. Satisfactory treatment of postburn contracture needs surgical excision of scar followed by Z-plasty. In case of a severe contracture of joints, Z-plasty is combined with skin grafting for the tension-free treatment of post-burn contracture. Methods: The study was conducted in Sadar Hospital, Sunamgonj and several private clinics in selected districts during the period from 2008 to 2020. Thirty (30) patients with contractures involving flexor surface of Elbow, Knee, and Metacarpophalangeal joints of hands of mild to severe degrees and various durations were treated with Z-plasty plus Split thickness Skin grafts. The operated limbs were immobilized with POP casts. Perioperative Parenteral Antibiotics were prescribed along with adequate Analgesics, Autiulcerants and vitamins, and proper nutrition. Both the operative sites (Recipient and donor areas) were examined by check dressing after the 7th to 14th postoperative days. Result: 5 and 12 patients had complications like infection, flap tip necrosis, and recurrent contractures respectively. But overall results were satisfactory in terms of joint extension, mobility, cosmetic appearance, and patient satisfaction. Very naturally in case of severe contractures, full correction was not possible by single-stage operation. Conclusion: Tension-free flap must be used in patients with mild to severe contractures. Combining skin Grafting with Z-plasty is easy and has better results than Z-plasty alone. It is recommended in patients of Z-plasty with intraoperative flap tension.

Coverage of Midline Back Wounds with Perforator-Based Pedicled Fasciocutaneous Flaps

Background: The number of patients with midline back wounds is increasing. Midline back wounds may cause skin and soft tissue defects, resulting in cavity formation and bone or orthopedic metallic hardware exposure. These complexities complicate coverage of the wounds. This study aimed to determine whether a perforator-based pedicled (island) flap was useful for the coverage of midline back wounds.Methods: After debridement of the wound, flaps were designed, dissected and inset into the midline wounds. The donor site was closed primarily. If the wound was too large to be covered with a unilateral flap, another flap at the contralateral site was used. Immediate and early postoperative position changes were made.Results: Between May 2011 and November 2019, 13 patients with skin and soft tissue defects of the midline back underwent coverage with perforator-based pedicled fasciocutaneous flaps. All flaps survived. Though flap tip necrosis and/or wound dehiscence occurred in five patients, total flap necrosis was not observed. Immediate postoperative position change was possible, allowing the patient to avoid flap ischemia.Conclusion: The perforator-based pedicled fasciocutaneous flap can be a useful option for covering midline back wounds with skin and soft tissue defects.

Clinical effects of free latissimus dorsi myocutaneous flap combined with artificial dermis and split-thickness skin graft in the treatment of degloving injury in lower extremity

Objective: To observe the clinical effects of free latissimus dorsi myocutaneous flap combined with artificial dermis and split-thickness skin graft in the treatment of degloving injury in lower limbs. Methods: A retrospective observational study was conducted. From December 2017 to December 2020, 8 patients with large skin and soft tissue defect caused by degloving injury in lower extremity were admitted to Ningbo No.6 Hospital, including 5 males and 3 females, aged from 39 to 75 years, with wound area of 25 cm×12 cm-61 cm×34 cm. The free latissimus dorsi myocutaneous flap with latissimus dorsi muscle in the width of 12-15 cm and flap area of 20 cm×8 cm-32 cm×8 cm was used to repair the skin and soft tissue defect of bone/tendon exposure site or functional area. The other defect was repaired with bilayer artificial dermis, and the flap donor site was sutured directly. After the artificial dermis was completely vascularized, the split-thickness skin graft from thigh was excised and extended at a ratio of 1∶2 to 1∶4 and then transplanted to repair the residual wound, and the donor site of skin graft was treated by dressing change. The survival of latissimus dorsi myocutaneous flap, artificial dermis, and split-thickness skin graft after operation was observed, the interval time between artificial dermis transplantation and split-thickness skin graft transplantation was recorded, and the healing of donor site was observed. The appearance and function of operative area were followed up. At the last outpatient follow-up, the sensory recovery of flap was evaluated by British Medical Research Council evaluation criteria, the flap function was evaluated by the comprehensive evaluation standard of flap in Operative Hand Surgery, the scar of lower limb skin graft area and thigh skin donor area was evaluated by Vancouver scar scale, and the patient's satisfaction with the curative effects was asked. Results: The latissimus dorsi myocutaneous flap survived in 6 patients, while the distal tip of latissimus dorsi myocutaneous flap was partially necrotic in 2 patient and was repaired by skin grafting after resection at split-thickness skin grafting. The artificial dermis survived in all 8 patients after transplantation. The split-thickness skin graft survived in 7 patients, while partial necrosis of the split-thickness skin graft occurred in one patient and was repaired by skin grafting again. The interval time between artificial dermis transplantation and split-thickness skin graft transplantation was 15-26 (20±5) d. The donor site of latissimus dorsi myocutaneous flap healed with linear scar after operation, and the thigh skin graft donor site healed with scar after operation. The patients were followed up for 6-18 (12.5±2.3) months. The color and elasticity of the flap were similar to those of the surrounding skin tissue, and the lower limb joint activity returned to normal. There was no increase in linear scar at the back donor site or obvious hypertrophic scar at the thigh donor site. At the last outpatient follow-up, the sensation of the flap recovered to grade S2 or S3; 3 cases were excellent, 4 cases were good, and 1 case was fair in flap function; the Vancouver scar scale score of lower limb skin graft area was 4-7 (5.2±0.9), and the Vancouver scar scale score of thigh skin donor area was 1-5 (3.4±0.8). The patients were fairly satisfied with the curative effects. Conclusions: In repairing the large skin and soft tissue defect from degloving injury in lower extremity, to cover the exposed bone/tendon or functional area with latissimus dorsi myocutaneous flap and the residual wound with artificial dermis and extended split-thickness skin graft is accompanied by harvest of small autologous flap and skin graft, good recovery effect of functional area after surgery, and good quality of healing in skin grafted area.

Rotation Advancement Keystone Flap for Closure of Large Myelomeningocele Defects.

Myelomeningocele is the most common form of neural tube anomalies. Early reliable skin coverage should be achieved to reduce central nervous system infections. The keystone flaps are gaining popularity for myelomeningocele defect reconstruction. However, the use of a traditional keystone flap is limited in very wide or transversely oriented myleomeningocele defects with inadequate lateral tissue laxity. In this study, we present our successful experience using modified rotation advancement keystone flaps for closure of the transversely oriented myelomeningocele defects. Between April 2019 and April 2020, the modified rotation advancement keystone flap was used for reconstruction of transversely oriented myelomeningocele defect in 7 patients (5 males and 2 females) with average age of 14 days. The localization of the lesions was lumbosacral in 5 patients and thoracolumbar in 2 patient. The average myelomeningocele defect width was 6.4 cm, whereas the average defect length was 5.7 cm. The following information was evaluated: the flap dimensions, operative time, and postoperative complications. All patients had uneventful operations, except for 1 case of superficial epidermolysis over flap tip, which settled with conservative wound management. Immediate venous congestion was detected in 2 patients that completely resolved. Otherwise, all wounds healed without any evidence of complications. The mean follow-up was 4 months. Although the conventional keystone flap seems to have geometric constraints to close a transversally oriented myelomeningocele defect, the modified rotation advancement keystone flap serves as a superior alternative and effective option for closure transversally oriented defect.

Effects of the G48M mutant on the dynamics properties and binding mechanism of PR with SQV and ATV

ABSTRACT The resistance of HIV-1 protease (PR) mutations seriously affects the efficiency of current drugs in the clinical treatment of AIDS. Therefore, it is important to understand the resistance mechanism of mutated residues for the development of PR inhibitors. In this work, the mechanism of G48M mutant PR to inhibitors Saquinavir and Atazanavir was studied by using molecular dynamics simulation combined with free energy prediction. The analysis results showed that, compared with the WT PR, the distance of the flap tip from the protease catalytic binding site and the dihedral angles in the flap regions in the mutant type complexes was changed. These changes resulted in a significant reduction in the occupancy of most of the hydrogen bonds in the mutant complex and the interaction energy of key residues with the inhibitor, which is the main reason for the resistance of the mutation to these inhibitors. This study can provide important guidance for the design of effective inhibitors against HIV-1 PR.