Surgical Treatment of Malignant Peripheral Nerve Sheath Tumor of the Scalp With Intracranial and Extracranial Extension: A Rare Case Report

ABSTRACT

Malignant peripheral nerve sheath tumors of the scalp are rare neoplasms of the peripheral nervous system. Here, we describe an unusual malignant peripheral nerve sheath tumor of the scalp in an 84-year-old Asian man. The tumor was associated with bony destruction, intracranial, and extracranial extension. Trans-arterial embolization was done twice preoperatively. En block excision was performed and the dura and soft tissue defect were reconstructed by anterolateral thigh free fasciocutaneous flap. There is no recurrence and the wound healed well during follow-up.

Reconstruction With Flow-Through Chimeric Anterolateral Thigh Flap Combining Vascularized Fibular Bone Graft for Extensive Composite Tissue Defect of the Forearm: A Case Report

ABSTRACT

The management of critical limb trauma is challenging because limb salvage is preferable to amputation. For upper limb reconstruction, the surgical restoration of functionality, and appearance, a multidisciplinary approach is needed. We report the case of an extensive composite tissue defect of the forearm caused by a machine-crushing injury that was repaired by a flow-through chimeric anterolateral thigh flap with a vascularized fibular graft. Reconstruction was performed as a single-stage procedure; no complications occurred, and both functional and aesthetic outcomes were satisfactory.

CD248 Regulates Inflammation and Encapsulation in Silicone-Related Capsule Formation

BACKGROUND

Capsular contracture is the most common reason for having a secondary breast implant operation. The failure of the implanted device and discomfort are related to foreign body response, which involves a pathologic encapsulation. An up-regulated expression of CD248 was previously demonstrated to modulate inflammation and fibrosis. The authors hypothesized that CD248 contributes to foreign body reaction and contracture during silicone-stimulated capsule formation.

METHODS

A murine capsular contracture model was established to correlate CD248 with capsular contracture. The timing and site of CD248 expression were characterized by protein analysis and histologic examination. The capsules between wild-type mice and CD248 knockout mice were compared in this model to verify the possible role of CD248 in silicone-related capsule formation.

RESULTS

CD248 was expressed in the peri-silicone implant capsule by stromal fibroblast and perivascular fibroblast. CD248 was overexpressed on day 4 and down to a constant level, but it was still up-regulated through day 21 to day 56 after silicone implantation. The CD248 knockout mice showed a prolonged inflammation period, whereas the wild-type mice developed a thinner but more collagenous capsule.

CONCLUSIONS

In conclusion, an effective murine capsular contracture model was established to study the relationship between CD248 and capsular contracture. CD248 may play a role in inflammation and encapsulation during silicone implantation. CD248 deletion in mice contributed to a loose and irregular collagen bundle in a capsule area, implying a decrease in contracture. Therefore, CD248 could be a potential therapeutic target in capsular contracture.

CLINICAL RELEVANCE STATEMENT

CD248 may play a role in inflammation and encapsulation during silicone implantation. It could be a potential therapeutic target in clinical capsular contracture.

Cross-cultural Comparison of an American and a Taiwanese Medical School with Longstanding Institutional Ties

Cross-cultural medical education has been suggested to train students to care for diverse patient populations and reform medical education systems. In this article, the authors conduct a cross-cultural comparison between two medical schools with a long-standing relationship - the Warren Alpert Medical School of Brown University in the United States and the School of Medicine of National Cheng Kung University in Taiwan - focusing on history, admissions, and curriculum.

Plate-related complication and health-related quality of life after mandibular reconstruction by fibula flap with reconstruction plate or miniplate versus anterolateral thigh flap with reconstruction plate

BACKGROUND

Plate-related complications are major long-term complications in mandible reconstruction. There are controversies regarding the use of a reconstruction plate versus miniplates and a bone flap versus a soft tissue flap with a bridging plate. Direct comparisons of a fibula flap and an anterolateral thigh flap, the applicability between a reconstruction plate and miniplate, and the correlation between plate-related complications and quality of life remain unclarified. Therefore, this study aimed to the explore complications of different flaps and plates and how they impact the patients' quality of life.

METHODS

We retrospectively reviewed the medical records of a total of 205 patients aged >18 years who underwent segmental mandibulectomy and reconstruction using fibula flap with reconstruction plate (FR; n = 86), fibula flap with miniplate (FM; n = 61), and anterolateral thigh flap with reconstruction plate (AR; n = 58) due to cancer ablation, osteoradionecrosis, or benign tumor excision between August 2010 and December 2019. Data on characteristics, complications, and health-related quality of life were collected and analyzed.

RESULTS

The plate-related complication rate was the highest in the AR group (37.9%), then in the FR group (25.6%), and was the lowest in the FM group (13.1%; p = 0.0079). The plate exposure rate was the highest in the AR group (24.1%), then in the FR group (15.7%), and was the lowest in the FM group (4.9%; p = 0.0128). The plate fracture and dislodge rates for the AR group were both higher than those for the FR and FM groups (24.1% versus 9.3% versus 9.8%, respectively; p = 0.023). The AR group had worse complication-free survival (hazard ratio [HR]: 3.61, 95% CI: 1.99-6.56, and p < 0.0001) than the FR and FM groups. Osteoradionecrosis (HR: 6.19, 95% CI: 2.11-18.21, and p = 0.0009) and postoperative radiotherapy (HR: 2.87, 95% CI: 1.34-6.12, and p = 0.0402) were both independent adverse factors for complication-free survival, whereas patient treated primarily (HR: 0.35, 95% CI: 0.17-0.73, and p = 0.0048) was an independent protective factor. Plate-related complication negatively impacted the quality of life based on pain scores (β: -0.56, SE: 0.26, and p = 0.034).

CONCLUSIONS

Using a fibular flap fixed with miniplates and avoiding the use of a reconstruction plate may yield a reduced plate exposure rate and better health-related quality of life, particularly for patients with osteoradionecrosis or those who need postoperative radiotherapy.

Perichondrial progenitor cells promote proliferation and chondrogenesis of mature chondrocytes

Autologous chondrocytes (C cells) are effective sources of cell therapy for engineering cartilage tissue to repair chondral defects, such as degenerative arthritis. The expansion of cells with C cell characteristics has become a major challenge due to inadequate donor sites and poor proliferation of mature C cells. The perichondrial progenitor cells (P cells) from the cambium layer of the perichondrium possessed significantly higher mesenchymal stem cell markers than C cells. In the transwell co-culture system, P cells increased the passaging capacity of C cells from P6 to P9, and the cell number increased 128 times. This system increased the percentage of Alcian blue-positive C cells from 40% in P6 to 62% in P9, contributing about 198 times more Alcian blue-positive C cells than the control group. C cells co-cultured with P cells also exhibited higher proliferation than C cells cultured with P cell-conditioned medium. Similar results were obtained in nude mice that were subcutaneously implanted with C cells, P cells or a mixture of the two cell types, in which the presence of both cells enhanced neocartilage formation in vivo. In aggregate, P cells enhanced the proliferation of C cells in a dose–dependent manner and prolonged the longevity of mature C cells for clinical applications.

Increasing burden of major trauma in elderly adults during 2003-2015: Analysis of real-world data from Taiwan

BACKGROUND

Major trauma has been one of the leading causes of morbidity, mortality, and functional disability, resulting in substantial societal burden. The aim of this study was to estimate the trends in burden of adult major trauma in Taiwan during 2003-2015.

METHODS

Adult patients with initial encounter of major trauma (injury severity score ≥ 16) were abstracted from the claim data of National Health Insurance (NHI) in Taiwan from January 2003 to December 2015. We explored the trends of incidence and mortality rates over time stratified by age and sex, as well as life expectancy (LE), loss-of-LE, lifetime healthcare expenditure and total loss-of-LE compared with age, sex and calendar-year matched referents simulated from the vital statistics of Taiwan.

RESULTS

A total of 71,731 cases of adult major trauma, and an estimated loss of 979,676 life-years were found with an increasing trend in cumulative incidence rate (CIR_18-84) during 2003-2015. The incidence rates were significantly higher in men than women. For both sexes, the incidence rates for those aged 65 and above were about 2-3 times higher than those of all other age groups. The one-year case fatality rates among the elderly were about 31-61%, higher than all other ages. The lifetime healthcare expenditures per person were 47,616 USD in men and 43,416 USD in women.

CONCLUSION

There is a consistently increasing trend in incidence and mortality of major trauma in Taiwan, especially among elderly people. For Taiwan, an aged society beginning since 2018, the challenge should be tackled more effectively in the coming decades.

Dynamic Traction Splint as an Alternative Surgical Treatment for Comminuted Intraarticular Fracture of Metacarpophalangeal Joint

BACKGROUND

Comminuted intraarticular fractures of the metacarpophalangeal joint (MPJ) are difficult to treat. We evaluated the clinical outcomes of using a dynamic traction splint to treat comminuted intraarticular fracture of MPJ.

PATIENTS AND METHODS

We conducted a retrospective chart review on patients with comminuted intraarticular fracture of the MPJ treated with a dynamic traction splint at National Cheng Kung University Hospital between March 2014 and February 2018. The surgical procedures consisted of a transverse Kirschner wire insertion and treatment for concomitant injuries. The patients then received staged regular rehabilitation programs under a hand therapists' supervision for 14 weeks. Active range of motion (ROM) of injured digits, Visual Analog Scale score for pain, and return-to-work status were recorded to evaluate functional outcomes.

RESULTS

A total of 10 patients were included. All were male patients and aged 8 to 66 years. The most common injury mechanism was motor vehicle accident (70%). The locations of fractures were 1 at the metacarpal head and 9 at the proximal phalangeal bases. Half of the fractures were open. Concomitant injuries were 1 digital nerve severance, 1 extensor tendon rupture, and 3 dorsal skin avulsions. There were no postoperative complications. The active ROM of the MPJ ranged from 40° to 90° with a median ROM of 80°. The Visual Analog Scale score for pain was 0 in 8 patients and 1 in the other 2 patients. All patients returned to their original workplace after rehabilitation.

CONCLUSIONS

Dynamic traction splints and postoperative rehabilitation programs could be an alternative treatment for comminuted intraarticular fracture of the MPJ.

Unilateral Vision Loss After Hyaluronic Acid Injection: A Case Report

ABSTRACT

Vascular occlusion causing vision loss is a rare yet one of the most devastating complications of facial esthetic fillers. In this article, we present a case of unilateral blindness and superficial skin necrosis in a 31-year-old woman after the injection of hyaluronic acid for esthetic purposes. The delicate ocular fundal findings of ophthalmic artery occlusion were demonstrated by ophthalmoscopy, optical coherence tomography, and fluorescein angiography. Magnetic resonance imaging also showed subsequent ischemic changes in the optic nerve and posterior scleral wall after ophthalmic artery occlusion. Despite management including intraocular pressure-lowering agents, globe massage, and anticoagulation with acetylsalicylic acid and hyperbaric oxygen therapy, her final vision was not restored. Given the lack of effective treatments, this report depicts the comprehensive ocular fundal findings of an ophthalmic artery occlusion after esthetic hyaluronic acid filler injection, and highlights the importance of a preventive approach to avoid such catastrophic complications.

A Touch-Observation and Task-Based Mirror Therapy Protocol to Improve Sensorimotor Control and Functional Capability of Hands for Patients With Peripheral Nerve Injury

IMPORTANCE

To develop a practical program in the early phase after nerve repair for more rapid return of function.

OBJECTIVE

To investigate the effects of touch-observation and task-based mirror therapy on the sensorimotor outcomes of patients with nerve repair.

DESIGN

An assessor-blinded study with a randomized controlled design.

SETTING

University hospital.

PARTICIPANTS

We recruited 12 patients with median or ulnar nerve repair between the level of midpalm and elbow referred by the plastic surgeons.

INTERVENTION

The patients were randomized into touch-observation and task-based mirror therapy or control groups, and both groups received training for 12 wk.

OUTCOMES AND MEASURES

The Semmes-Weinstein monofilament (SWM) test, two-point discrimination test, Purdue Pegboard Test (PPT), Minnesota Manual Dexterity Test (MMDT), and pinch-holding-up activity test were assessed at pretreatment, immediately after treatment, and 12 wk after the last treatment.

RESULTS

The experimental group showed greater improvements in the results of the pinch-holding-up activity test and the PPT Unilateral Pin Insertion, Bilateral Pin Insertion, and Assembly subtests. However, change on the SWM test revealed no significant difference between the two groups.

CONCLUSIONS AND RELEVANCE

Touch-observation and task-based mirror therapy is an effective but low-cost treatment protocol to optimize sensorimotor control and functional capability of the upper limb in patients with peripheral nerve injury.

Esophageal reconstruction after oncological total laryngopharyngoesophagectomy: Algorithmic approach

BACKGROUND

Reconstruction for total laryngopharyngoesophagectomy is accomplished mainly by gastrointestinal transposition but can be complicated by anastomotic tension or associated neck-skin defect. Here, we present the results of total esophageal reconstruction by gastrointestinal transposition alone or with additional free tissue transfer and propose an algorithm accordingly.

METHODS

We reviewed patients who had oncologic total laryngopharyngoesophagectomy between January 2012 and January 2016. Twenty-four men and one woman were included with a mean age of 54 (range, 41-72) years. Patients were grouped by reconstruction into the gastric pull-up (GP, n = 15), colon interposition (CI, n = 2), GP combined with free jejunal flap (GPFJ, n = 6), or GP combined with anterolateral thigh flap (GPALT, n = 2) group to compare clinical outcomes.

RESULTS

The mean operation time was 1037.3 minutes and was significantly longer in the GPALT group than in the GP group (1235.0 ± 50.0 minutes vs. 929.7 ± 137.7 minutes, p =.009). All flaps survived. After a mean follow-up of 18 months, the overall leakage, stricture, and successful swallowing rates were 44%, 4%, and 76%, respectively. There was no significant difference in the leakage (53.3%, 50.0%, 16.7%, and 50.0%, p =.581), stricture (6.7%, 0%, 0%, and 0%, p = 1.000), or successful swallowing (73.3%, 50.0%, 83.3%, and 100%, p =.783) rates between GP, CI, GPFJ, and GPALT groups, respectively.

CONCLUSIONS

The proposed algorithm that ranks gastric pull-up as a priority and uses additional free tissue transfer to overcome the anastomotic tension or associated neck-skin defect is feasible.

Determining the functional sensibility of the hand in patients with peripheral nerve repair: Feasibility of using a novel manual tactile test for monitoring the progression of nerve regeneration

STUDY DESIGN

Case-controlled cohort study.

INTRODUCTION

Sensory function is difficult to observe during nerve regeneration processes. Traditional sensory tests are limited to identifying the level of functioning hand sensation for sensory stimulus is given passively to the cutaneous surface of the hand.

PURPOSE OF THE STUDY

To examine the outcome changes in the manual tactile test (MTT), Semmes-Weinstein monofilament (SWM) and 2-point discrimination (2PD) tests for patients with nerve repair and to investigate the concurrent validity of MTT by comparing it with the results of traditional tests.

METHODS

Fifteen patients with nerve injury of the upper limbs were recruited, along with 15 matched healthy controls. The MTT, SWM, and 2PD tests were used to examine the sensory status of the subjects.

RESULTS

Three subtests (barognosis, roughness differentiation, and stereognosis) in MTT showed that the patients improved with time. A moderate and mild correlation was found between the MTT and 2PD results and between the barognosis and SWM results.

CONCLUSIONS

The MTT provides practical and functional perspectives on detecting nerve progression during the courses of degeneration and regeneration.

LEVEL OF EVIDENCE

IV.

Regeneration and repair of human digits and limbs: fact and fiction

A variety of digit and limb repair and reconstruction methods have been used in different clinical settings, but regeneration remains an item on every plastic surgeon's "wish list." Although surgical salvage techniques are continually being improved, unreplantable digits and limbs are still abundant. We comprehensively review the structural and functional salvage methods in clinical practice, from the peeling injuries of small distal fingertips to multisegmented amputated limbs, and the developmental and tissue engineering approaches for regenerating human digits and limbs in the laboratory. Although surgical techniques have forged ahead, there are still situations in which digits and limbs are unreplantable. Advances in the field are delineated, and the regeneration processes of salamander limbs, lizard tails, and mouse digits and each component of tissue engineering approaches for digit- and limb-building are discussed. Although the current technology is promising, there are many challenges in human digit and limb regeneration. We hope this review inspires research on the critical gap between clinical and basic science, and leads to more sophisticated digit and limb loss rescue and regeneration innovations.

Counting CD4(+) and CD8(+) T cells in the spleen: a novel in vivo method for assessing biomaterial immunotoxicity

As immunotoxicity assessments of newly developed biomaterials are often restricted to use in assessment of local tissue response at the implantation site, they do not always show an immune response acceptable to qualify them for clinical use. We tested a new method to assess systemic toxicity: counting the CD4⁺ and CD8⁺ cells in the spleen. Three different biomaterials were subcutaneously implanted in three groups of rats for the same time period. After 31 days, their spleens were harvested, and CD4⁺ and CD8⁺ cells were counted. The mean CD4⁺/CD8⁺ cell counts were 24.5 ± 3.6/19.8 ± 4.0 (porous collagen matrix group), 25.5 ± 7.1/21.6 ± 3.8 [synthetic collagen matrix (Duragen®) group] and 28.1 ± 4.1/19.6 ± 3.7 (porcine dermis group). Differences in cell counts were not significant. The immunotoxic response generated against porous collagen matrix was comparable to that produced by a similar biomaterial already used clinically. This is, to the best of our knowledge, the first study on cytotoxic lymphocytes in the spleen to quantify systemic immune response to a biomaterial; however, such studies have been conducted with bacterial and viral antigens, and with vaccines. We believe that the present study provides a viable method for larger studies to confirm our current findings.

Prognostic factor of mortality and its clinical implications in patients with necrotizing fasciitis caused by Vibrio vulnificus

In Taiwan, the aquatic environment and endemic hepatitis contribute to the high susceptibility of Vibrio vulnificus infection. A multidisciplinary treatment protocol for necrotizing fasciitis caused by V. vulnificus was developed in our institute, namely, ceftriaxone or ceftazidime combined with doxycycline or minocycline followed by an emergency fasciotomy and intensive care unit admission. We retrospectively reviewed 100 cases to evaluate the effectiveness of our treatment protocol and identify independent predictors of mortality to improve clinical outcomes. Cases of culture-confirmed V. vulnificus infection between January 1996 and December 2011 were reviewed. Necrotizing fasciitis was surgically diagnosed if these criteria were met: necrotic fascia, "dishwater discharge", and loss of resistance while doing finger dissection along the fascia plane. One hundred cases met these criteria and were included for analysis. Eighteen patients died (18 % mortality). Unknown injury events, presence of multiple skin lesions, leukocytes < 10,000 cells/mm(3), platelets < 100,000/mm(3), serum creatinine ≥1.3 mg/dL, serum albumin < 2.5 mg/dL, and delayed treatment beyond 3 days post-injury or symptom onset were associated with significantly higher mortality. Multivariate analysis showed that treatment delayed beyond 3 days is an independent factor indicating a poor prognosis (OR 10.75, 95 % CI 1.02-113.39, p = 0.048). Early diagnosis and prompt treatment within 3 days post-injury or symptom onset should be the goal for treating patients with necrotizing fasciitis caused by V. vulnificus. Additional investigations to rescue patients with a prolonged disease course of necrotizing fasciitis (≥3 days) may be important.

Prediction of hand strength by hand injury severity scoring system in hand injured patients

PURPOSE

Hand strength is a key component in human hand function, especially to those with strength-required jobs. To evaluate post-injury hand strength, this study was conducted to assess the predictability of hand injury severity scoring (HISS) system to hand strength after a period of recovery.

METHODS

In this retrospective study, 80 traumatic hand-injured subjects were recruited. Hand strength tests measured by dynamometers were performed by subjects in ways of palmar pinch, lateral pinch and cylindrical grip. The logistic regression models were used to evaluate the risk of poor hand strength among the severities represented by HISS scores.

RESULTS

A positive correlation exists between the differences of the strength of two hands, and the severity shown by HISS system in the poorer half of subjects. The risk to be in poorer half of palmar pinch subtest is significant in moderate subgroup of HISS severity. The risk to be in poorer half of cylindrical grip subtest is significant in major subgroup of HISS severity. The risk to be in poorer half of palmar pinch and cylindrical grip subtests is significant in skeletal component of HISS system.

CONCLUSIONS

HISS is a descriptive severity scoring system to hand injury and also a useful instrument to predict functional outcome. This study revealed the HISS system may predict post-injury hand strength after recovery.

Correlation of digital sensibility and precision of pinch force modulation in patients with nerve repair

The outcome measures for patients following peripheral nerve repairs commonly include muscle strength and sensory assessments. However, no significant discussion exists on the impact of nerve injury on sensorimotor control. The objective of this longitudinal study was to explore the effects of nerve regeneration on the control of pinch force in executing functional tasks. Seven patients with digital or median nerve repairs were assessed by a custom-designed pinch device and conventional sensory tools at monthly intervals following nerve repair. These tools measured sensibility, maximum pinch strength, and anticipated pinch force adjustments to movement-induced load fluctuations in a pinch-holding-up activity (PHUA). Six force-related and temporal parameters for sensory measurement were used to determine improvements in pinch performance over time following sensory recovery. The results revealed significant differences in the parameters of peak pinch force, baseline pinch force, force ratio, and the percentage of maximal pinch force output at different points in the course of nerve regeneration. A strong relationship was also found between kinetic data from the PHUA test and the traditional sensibility tests for the nerve repair patients in the present study.

Deep partial thickness burn blister fluid promotes neovascularization in the early stage of burn wound healing

The effect of burn blister fluid in neovascularization during burn wound healing is unknown. Burn blister fluid, containing a large amount of chemokines, is thought to play a role in the early stage of neovascularization. This process includes angiogenesis and vasculogenesis. Because of different healing time of burn wounds, we hypothesized that neovascularization in superficial partial thickness burn (SPTB) and deep partial thickness burn (DPTB) wounds were different. The neovasculogenic effects of two different burn blister fluids were also different. We found Day 7 DPTB wounds had a significant increase in blood vessels compared with SPTB wounds by immunohistochemistry. DPTB blister fluid significantly promoted neovascularization via increasing endothelial cell proliferation, and migration and differentiation of circulating angiogenic cells relative to SPTB blister fluids. In the animal study, DPTB blister fluids markedly promoted new blood vessel formation compared with those from SPTB blister fluids using in vivo Matrigel plug assay. These results suggest that DPTB wounds require more new vessel formation than SPTB. Furthermore, the measurement of angiogenic activities in burn blister fluids serves as a possible tool for assessing burn wound status.

Reconstruction of a massive femoral bone defect using a double-barreled free vascularized fibular bone graft after wide resection of femoral chondrosarcoma

Salvaging the limb after malignant bone tumor ablation is a tough challenge for a reconstructive surgeon confronting such extensive bone defects. A 40-year-old male without any underlying disease was incidentally diagnosed with a chondrosarcoma over his left femoral bone. An orthopedic surgeon did a wide resection of the malignant bone tumor, leaving a massive bone defect about 11.3 cm in length. A double-barreled free vascularized fibular bone was designed to reconstruct the femoral bone defect. The maximal fibular bone graft harvested was 19 cm long; after the osteotomy, one barrel was 11 cm and the other was 8 cm. An iliac crest cancellous bone graft was harvested to fill the residual space. The pathology report showed a grade 1 well-differentiated conventional chondrosarcoma, and further adjuvant therapy was not suggested. At a 3-year follow-up, plain radiography showed a good bony union of the graft, and the patient could easily tolerate daily activity. A vascularized double-barreled fibular graft is an ideal option for reconstructing a massive defect in weight-bearing bone: it provides not only sufficient mechanical strength but also good union for early rehabilitation. We describe the long-term results after reconstruction and provide a literature review of long-bone chondrosarcoma.

Secondary nerve reconstruction using vein conduit grafts for neglected digital nerve injuries

Digital nerve defects can result from neglected nerve injuries. The standard method of reconstruction is nerve grafting, but donor-site morbidity encourages searching for alternative graft materials, including vein conduit grafts. From 1995-2005, three patients with neglected digital nerve injuries received vein conduit grafting for digital nerve reconstruction in our hospital. The interval between the injury and the reconstructive procedure ranged from 17 days to 2 years, and the length of the defects ranged from 0.8 to 2.5 cm. All the vein grafts were harvested from the distal forearm. Patient 1 had a moving and a static two-point discrimination (M2PD and S2PD) of 3 and 4 mm, respectively, at a 12-year follow-up. Patient 2 had an M2PD of 5 mm and S2PD of 6 mm at an 11-year follow-up, and the patient 3 had both an M2PD and S2PD of 4 mm at a near 3-year follow-up. They all achieved useful sensory function (S3 and S3+) by modified Highet and Sander criteria. Although previous studies showed secondary repair using vein grafts yielded worse sensory recovery than that of primary repair, in our cases, secondary digital nerve reconstruction with vein conduit grafts gives excellent results at the long-term sensory evaluation, two of them with more than 10 years' follow-up. To the best of our knowledge, this might be the longest follow-up after secondary digital nerve reconstruction using a vein conduit graft. It bears the advantages of readily accessible, no donor-site morbidity, and compatible in size with digital nerves.

Long-term functional results of primary reconstruction of severe forearm injuries

Severe forearm injuries caused by machinery such as a power saw represented about 0.2% of all upper limb injuries operated on in the plastic surgery section of our institute between 1993 and 1997. These are complex and contaminated injuries with severe damage to skin, muscles, tendons, nerves, vessels and bones. Primary repair or reconstruction of all the divided vital structures was carried out in our series of four patients, including one 4-cm cable nerve graft for a median nerve defect. After an average 22-month follow up, the functional results showed grade M4 motor recovery and better than grade S3+ sensory recovery of the hand in all four patients. We suggest that a definitive primary procedure is best when possible. This will achieve a better functional outcome from early neural regeneration, and will reduce the frequency of secondary procedures, cause less scarring, and shorten the duration of hospital stays and rehabilitation periods.

Neurofibroma derived from the deep peroneal nerve: a case report

Neurofibromas may arise anywhere along a nerve from the dorsal root ganglion to the terminal nerve branches; however, peroneal nerve involvement is not common. Surgical resection of neurofibroma with total preservation of nerve function had been thought to be difficult. Here, we report a case of an intermuscular intraneural neurofibroma derived from the deep peroneal nerve in a patient with neurofibromatosis type 1. The diagnostic criteria, characteristics of imaging studies, and operative approach are described. The function of the deep peroneal nerve was preserved, with satisfactory results.

Distally Based Anterolateral Thigh Flap: An Anatomic and Clinical Study

The distally based anterolateral thigh flap has been used for coverage of soft-tissue defects of the knee and upper third of the leg. This flap is based on the septocutaneous or musculocutaneous perforators derived from the lateral circumflex femoral system. The purpose of this study was to examine the results of anatomical variations of the descending branch of the lateral circumflex femoral artery and the retrograde blood pressure of the descending branch of the lateral circumflex femoral artery so that the surgical technique for raising and transferring a distally based anterolateral thigh flap to the knee region could be improved. The authors have actually used this flap in three cases. In 11 thighs of six cadavers, the descending branch of the lateral circumflex femoral artery had a rather consistent connection with the lateral superior genicular artery or profunda femoral artery in the knee region. The pivot point, located at the distal portion of the vastus lateralis muscle, ranges from 3 to 10 cm above the knee. In their three cases, the maximal flap size was 7.0 x 16.0 cm and was harvested safely, without marginal necrosis. The mean pedicle length was 15.2 +/- 0.7 cm (range, 14.5 to 16 cm). The average proximal and distal retrograde blood pressure of the descending branch of the lateral circumflex femoral artery was also studied in another 11 patients, and the anterolateral thigh flap being used for reconstruction of head and neck defects showed 58.3 and 77.7 percent of proximal antegrade blood pressure, respectively. The advantages of this flap include a long pedicle length, a sufficient tissue supply, possible combination with fascia lata for tendon reconstruction, and favorable donor-site selection, without sacrifice of major vessels or muscles.

Tissue engineering auricular reconstruction: in vitro and in vivo studies

Although investigators have demonstrated that neocartilage can be constituted in a predetermined shape and in complex three-dimensional structures, such as a human ear, by using cell transplantation on polymer constructs, many unsolved problems still remain. The crucial issues for auricular tissue engineering consisted of optimal cell culture environment, choice of polymers, behavior of chondrocytes, study of cell-polymer constructs in an acceptable animal model, and long-term structural integrity. Here we describe our tissue engineering approaches for auricular reconstruction including auricular scaffold fabrication, in vitro chondrogenesis, in vivo immunocompromized xenograft and immunocompetent autologous animal models, and long-term follow-up. Though many current obstacles regarding auricular tissue engineering still exist, we demonstrate techniques of auricular scaffold fabrication with promising in vitro and in vivo neocartilage formation, optimal selection and application of animal models, and, to the best of our knowledge, the first report of different biodegradable biomaterial trials and the longest in vivo results (10 months) for auricular tissue engineering.

A novel platelet-rich arterial thrombosis model in rabbits. Simple, reproducible, and dynamic real-time measurement by using double-opposing inverted-sutures model

Though numerous animal thrombosis models have been introduced, an easy, reliable, and reproducible arterial thrombosis model remains a continuing challenge prior to a thrombolytic study. In an effort to evaluate the efficiency of various recombinant thrombolytic agents with specific affinity to activated platelets in vivo, we developed a novel double-opposing inverted-sutures model to create a platelet-rich thrombus in the femoral artery of rabbits. The arteriotomy was done semicircumferentially, and variously sized microsurgical sutures were introduced intraluminally in a double-opposing inverted manner. The animals were divided into three groups according to the double-opposing inverted-sutures used: Group 1 with 10-0 nylon (n=6), Group 2 with 9-0 nylon (n=6), and Group 3 with 8-0 nylon (n=22). The superficial epigastric branch was cannulated with a thin polyethylene (PE) tube for intraarterial administration of the studied thrombolytic agent. The blood flow was continuously measured with a real-time ultrasonic flow meter. Within 2 h of installation of the sutures, there was no thrombus formation in either Group 1 or 2. In Group 3, the thrombosis rate was 91% (20 of 22) under a steady baseline flow (with an average of 12.23+/-2.40 ml/min). It was highly statistically significant with a P-value of .0000743 using Fisher's Exact Test. The averaged time to thrombosis was 21.8+/-9.8 min. The ultrasonic flow meter to record the dynamic real-time measurement of blood flow was a guideline for thrombus formation or dissolution, which was correlated with the morphological findings of stenotic status of the vessel detected by the Doppler sonography. The components of the thrombus were proven to be platelet-rich predominant by histological examination via hematoxylin and eosin (H&E) stain and transmission electron microscopy (TEM). To confirm that the double-opposing inverted-sutures model would be useful for a study of thrombolytic agents, we evaluated the effects of recombinant tissue-type plasminogen activator (rt-PA) and streptokinase-human plasminogen (SK-HPlg). The average time to thrombolysis post rt-PA infusion was 16.0+/-8.2 min and that of SK-HPlg was 79.6+/-23.1, which were similar to the previous reports. In conclusion, the novel double-opposing inverted-sutures (8-0 nylon) model provides a simple, reliable, and reproducible platelet-rich arterial thrombosis model with noninvasive and dynamic real-time measurement. It may be applied in assessing the efficiency of the recombinant thrombolytic agents and offers many advantages of an arterial platelet-rich in vivo thrombosis model.

Reconstruction of the Achilles tendon and overlying soft tissue using antero-lateral thigh free flap

Reconstruction of combined loss of the Achilles tendon and overlying soft tissue was performed using an antero-lateral thigh free flap in three patients. The cutaneous portion is used to cover the open wound, and a piece of fascia lata is utilised to replace the missing segment of the Achilles tendon. The skin defect ranged from 5 x 2.5 to 7 x 5 cm, and the tendon loss measured from 3.5 to 5.5 cm in length. All of the patients showed satisfactory functional results with a follow-up period from 3 to 9 months. The advantages of the procedure are that: it is a single-staged operation; it promotes rapid healing of the tendo Achilles since the tendon substitute is well vascularised; it is adaptable to a wide range of defect sizes and shapes; it can be performed in the supine position without the need for postural change; and it can restore good contour and causes minimal morbidity at the donor site.

Long-term effects of sensory reeducation following digital replantation and revascularization

The long-term maintenance of sensory gain following sensory reeducation is still unknown for replanted digits. Ten patients with 18 replanted or revascularized digits, who had received a formal sensory reeducation program for 1.5 years postoperatively, were reevaluated with moving two-point discrimination and Semmes-Weinstein pressure threshold test after discontinuing sensory reeducation for 1 year. Another four patients with seven replanted or revascularized digits, who have never received sensory reeducation after surgery, were also followed up in the same way. After cessation of sensory reeducation, the degree of moving two-point discrimination became significantly worse in the formal sensory-reeducated group (P < 0.05) and significantly improved in the group without sensory reeducation initially (P < 0.05), whereas it showed a nonsignificant change of Semmes-Weinstein threshold both in the group with formal sensory reeducation and without sensory reeducation. Sensory retraining did influence the progressive change of moving two-point discrimination, but not in a parallel way with the Semmes-Weinstein threshold test.

Free anterolateral thigh flap for reconstruction of head and neck defects following cancer ablation

Thirty-seven consecutive free anterolateral thigh flaps in 36 patients were transferred for reconstruction of head and neck defects following cancer ablation between January of 1997 and June of 1998. The success rate was 97 percent (36 of 37), with one flap lost due to a twisted perforator. The anatomic variations and length of the vascular pedicle were investigated to obtain better knowledge of anatomy and to avoid several surgical pitfalls when it is used for head and neck reconstruction. The cutaneous perforators were always found and presented as musculocutaneous or septocutaneous perforators in this series of 37 anterolateral thigh flaps. They were classified into four types according to the perforator derivation and the direction in which it traversed the vastus lateralis muscle. In type I, vertical musculocutaneous perforators from the descending branch of the lateral circumflex femoral artery were found in 56.8 percent of cases (21 of 37), and they were 4.83 +/- 2.04 cm in length. In type II, horizontal musculocutaneous perforators from the transverse branch of the lateral circumflex femoral artery were found in 27.0 percent of cases (10 of 37), and they were 6.77 +/- 3.48 cm in length. In type III, vertical septocutaneous perforators from the descending branch of the lateral circumflex femoral artery were found in 10.8 percent of cases (4 of 37), and they were 3.60 +/- 1.47 cm in length. In type IV, horizontal septocutaneous perforators from the transverse branch of the lateral circumflex femoral artery were found in 5.4 percent of cases (2 of 37). They were 7.75 +/- 1.06 cm in length. The average length of vascular pedicle was 12.01 +/- 1.50 cm, and the arterial diameter was around 2.0 to 2.5 mm; two accompanying veins varied from 1.8 to 3.0 mm and were suitable for anastomosis with the neck vessels. Reconstruction of one-layer defect, external skin or intraoral lining, was carried out in 18 cases, through-and-through defect in 17 cases, and composite mandibular defect in two cases. With increasing knowledge of anatomy and refinements of surgical technique, the anterolateral thigh flap can be harvested safely to reconstruct complicated defects of head and neck following cancer ablation with only minimal donor-site morbidity.

The application of scanning acoustic microscopy in a bone remodeling study

Scanning acoustic microscopy (SAM) was used in the evaluation of bone remodeling around a cylindrical unicortical defect. SAM is a technique for the nondestructive evaluation of materials, and has only recently been employed as an orthopaedic research tool. The utility of SAM was demonstrated by using it to measure an elastic property known as acoustic impedance. Specifically, the acoustic impedance of bone formed by remodeling around a cylindrical defect was measured. The defects were filled with either a low modulus "void" or rigid inclusion to create various states of stress in the bone in the vicinity of the defect. After six months of implantation of the inclusions in the sheep metatarsal, new bone formation on periosteal and endosteal surfaces about the defect region was observed. These regions of new bone were less stiff and had 18.0 +/- 6.5% lower acoustic impedance than the pre-existing bone in the intracortical region of the metatarsal. There was no difference in the degree of new bone formation about void and rigid inclusions. Both underwent significant adaptational changes in response to the elevated stress about the defect. These changes affected the basic structure of the bone cross-section at the level of the defect and effectively reduced the stress levels about the defect. By using SAM to measure acoustic impedance, it was seen that little internal remodeling occurred in the intracortical region. Hence, the primary mechanism of strain-induced bone remodeling observed in this experimental model was surface remodeling.

Evaluation of the effectiveness of sensory reeducation following digital replantation and revascularization

Sensory recovery following digital replantation plays an important role in the restoration of hand function. Twelve patients with twenty-four replanted or revascularized digits were randomly selected to enter a program of sensory reeducation, and another 15 patients with 22 replanted or revascularized digits were selected as controls who did not receive sensory reeducation. A moving two-point discrimination and a Semmes-Weinstein pressure threshold test were evaluated for monitoring the sensory recovery. The period of sensory reeducation was 18.83 weeks on average, and the mean follow-up time was 11.94 months. The group that received sensory reeducation significantly improved to a better degree of moving two-point discrimination and Semmes-Weinstein threshold level by both univariate and multiple regression analysis. We suggest that sensory reeducation should be an integral part of the postoperative rehabilitation protocol following digital replantation and revascularization.

Multivariate analysis of factors influencing the functional recovery after finger replantation or revascularization

A multivariate statistical analysis was utilized to study the influence of the four preoperative (age, mechanism of injury, level of injury, and type of amputation) and one postoperative (rehabilitation) variables on the functional recovery of the replanted or revascularized finger. Statistically significant differences are summarized as follows. The young age group have a better functional recovery due to better sensory recovery than the old age group. The crush injury group have a better functional recovery, with better scores in motion and patient satisfaction, than the avulsion injury group. The middle phalangeal injury group have a better functional recovery, with better score in motion and sensation than the proximal phalangeal injury group. There is no statistically significant difference in functional recovery between the revascularized and replanted fingers, but there is a significantly better sensory recovery in the revascularized finger. The rehabilitation group has a better functional recovery, with better score in motion, subjective symptoms, and patient satisfaction, than the nonrehabilitation group.

Preliminary characterization of bioresorbable and nonresorbable synthetic fibers for the repair of soft tissue injuries

Preliminary characterizations of two new synthetic fibers were performed to determine their potentials for use in soft tissue scaffolding devices. A slowly bioresorbing random copolymer of dimethyltrimethylene carbonate (DMTMC) and trimethylene carbonate (TMC) was the first fiber evaluated. The second was a nonresorbable high-strength synthetic fiber of highly oriented polyethylene. Their in vitro mechanical behavior was evaluated by loading fibers in uniaxial tension to determine mechanical properties in dry and wet (saline) environments. The polyethylene fiber had a dry strength of approximately 2.0 GPa, an ultimate strain of 3 to 4%, a tangent modulus of 57 GPa, and was not affected by the saline environment. The bioresorbable fiber had a dry strength of approximately 500 MPa, an ultimate strain of 35%, and tangent modulus of 5.4 GPa. The in vitro resorption of the bioresorbable fibers produced a 15% loss in strength over a 10-week period. In vitro cell-fiber compatibility studies were conducted to assay material biocompatibility and fiber substrate efficacy. Fibroblasts proliferated and migrated on both the polyethylene and bioresorbable fibers at rates similar to those previously found for other compatible fibers, thus demonstrating the new materials to be similar in their in vitro biocompatibility profiles. Morphological assessment with SEM also confirmed that these materials were suitable substrates for cell attachment. A rabbit Achilles tendon repair model using oriented polyethylene or bioresorbable fiber tows was evaluated after 12 and 26 weeks of implantation. The mechanical performances of both types of tendon repairs were similar to those found in previous studies using carbon or PET fibers. The polyethylene fibers elicited a low-grade chronic inflammatory tissue response. The bioresorbable fibers were still intact at 26 weeks and remained relatively inert in the host tissue, eliciting a minimal foreign body response.

Mechanical properties of collagen fibres: a comparison of reconstituted and rat tail tendon fibres

This study involves comparison of the mechanical properties of reconstituted collagen fibres with those of collagen fibres obtained from rat tail tendons. Reconstituted collagen fibres were cross-linked in the presence of glutaraldehyde vapour for 2 and 4 d or using a combination of severe dehydration and carbodiimide treatment. Ultimate tensile strengths for reconstituted fibres cross-linked with glutaraldehyde ranged from 50 to 66 MPa while those cross-linked by severe dehydration and carbodiimide treatment had ultimate tensile strengths between 24 and 31 MPa. Rat tail tendon fibres had tensile strengths that ranged from 33 to 39 MPa. These results indicate that high-strength collagen fibres can be reconstituted in vitro and that these fibres may be useful in repair of dermal, dental, cardiovascular and orthopaedic defects.