Significant relationship between musculoaponeurotic attachment of the abdominal and thigh adductor muscles to the pubis: implications for the diagnosis of groin pain

Groin pain is prevalent in orthopedic and sports medicine, causing reduced mobility and limiting sports activity. To effectively manage groin pain, understanding the detailed anatomy of supporting muscles is crucial. This study aimed to investigate the musculoaponeurotic attachments on the pubis and the relationship among intramuscular aponeuroses of abdominal and thigh adductor musculatures. Macroscopic analyses were performed in 10 pelvic halves. The bone morphology of the pubis was assessed in two pelvic halves using microcomputed tomography. Histological investigations were conducted in two pelvic halves. The external oblique aponeurosis extended to the adductor longus aponeurosis, forming conjoined aponeurosis, which attached to a small impression distal to the pubic crest. The gracilis aponeurosis merges with the adductor brevis aponeurosis and is attached to the proximal part of the inferior pubic ramus. The rectus abdominis and pyramidalis aponeuroses were attached to the pubic crest and intermingled with the gracilis-adductor brevis aponeurosis, forming bilateral conjoined aponeurosis, which attached to a broad area covering the anteroinferior surface of the pubis. Histologically, these two areas of conjoined aponeuroses were attached to the pubis via the fibrocartilage enthesis. Microcomputed tomography revealed two distinctive bone morphologies, a small impression and an elongated osseous prominence on pubis, corresponded to the two areas of conjoined aponeuroses. This study demonstrated close relationships between the aponeurotic attachment of the external oblique and adductor longus, and between the rectus abdominis, pyramidalis, gracilis, and adductor brevis. The findings of aponeurotic complexes would aid in diagnostic and surgical approaches for athletic groin pain.

The Effect of Additional External Resistance on Inter-Set Changes in Abdominal Muscle Thickness during Bridging Exercise

Bridging exercises with abdominal hollowing are often used as a regimen for improving spinal stability. Lately, this type of training has become very popular among elite athletes, creating a need for more demanding exercises. The purpose of this study was to investigate whether the use of additional external resistance is beneficial for abdominal muscle recruitment during bridge exercise. Tissue movement of the transversus abdominis (TrA) and the rectus abdominis (RA) was recorded with the use of two synchronized ultrasonic devices, in 20 healthy college students. From the hook-lying position participants were examined in eight different exercise conditions: a) rest, b) abdominal drawing-in maneuver (ADIM), c) bridge, d) bridge- ADIM, e) bridge with 10KG, f) bridge- ADIM with 10KG, g) bridge with 20KG and h) bridge-ADIM with 20KG. Analysis of variance (ANOVA) showed a statistically significant increase in TrA thickness when performing the bridge exercise combined with ADIM compared to rest mode (p < .05). RA thickness decreased when the ADIM was performed, compared to rest (p < 0.05). No significant difference in TrA and RA thickness when exercising with and without external resistance was observed (p > 0.05). The main outcome of this study was that external loading provided some extra level of difficulty, yet it was not beneficial for abdominal muscle recruitment, when performing a supine bridge exercise.

Premorbid obesity, but not nutrition, prevents critical illness-induced muscle wasting and weakness

BACKGROUND

The 'obesity paradox' of critical illness refers to better survival with a higher body mass index. We hypothesized that fat mobilized from excess adipose tissue during critical illness provides energy more efficiently than exogenous macronutrients and could prevent lean tissue wasting.

METHODS

In lean and premorbidly obese mice, the effect of 5 days of sepsis-induced critical illness on body weight and composition, muscle wasting, and weakness was assessed, each with fasting and parenteral feeding. Also, in lean and overweight/obese prolonged critically ill patients, markers of muscle wasting and weakness were compared.

RESULTS

In mice, sepsis reduced body weight similarly in the lean and obese, but in the obese with more fat loss and less loss of muscle mass, better preservation of myofibre size and muscle force, and less loss of ectopic lipids, irrespective of administered feeding. These differences between lean and obese septic mice coincided with signs of more effective hepatic fatty acid and glycerol metabolism, and ketogenesis in the obese. Also in humans, better preservation of myofibre size and muscle strength was observed in overweight/obese compared with lean prolonged critically ill patients.

CONCLUSIONS

During critical illness premorbid obesity, but not nutrition, optimized utilization of stored lipids and attenuated muscle wasting and weakness.

[The imaging study of internal mammary artery and its branches ]

OBJECTIVE

To investigate the distribution of the internal mammary artery and its branches by the multi-slice spiral CT angiography, and to explore the feasibility of transferring pedicled transverse rectus abdomials myocataneous (TRAM) flap for breast reconstruction through resection of inferior costicartilages.

METHODS

30 female patients received abdominal CT angiography. (1) The distance between internal mammary artery and the sternum midline were recorded; (2) The position and the numbers of branches from bilateral internal mammary arteries at the level of 5th, 6th, 7th rib was observed; (3) The points where the superior epigastric artery gets through the rectus abdominis muscle were located.

RESULTS

( The average distance between left internal mammary artery to the sternum midline is from 1. 66 cm (0. 62-2. 39 cm ) to 2.34 cm (0.69-3.36 cm) at the level from 4th to 6th intercostal space. The average distance between right internal mammary artery to the sternum midline is from 1.55 cm(0. 66-2. 29 cm) to 2.29 cm(0. 73-3. 67 cm) at the level from 4th to 6th intercostal space; ) The number of branches is the most at the level of 6th intercostal space; (3) There are 235 branches in the superior epigastric artery.

CONCLUSIONS

This imaging study of internal mammary artery explores the feasibility of transferring pedicled transverse rectus abdominals myocataneous flap for breast reconstruction. It has important significance in the breast reconstruction using TRAM flap with lengthened pedicle.

[Histological changes after the recontruction of tongue defect with rectus abdominis musculoperitoneal flap]

OBJECTIVE

To observe the cellular morphological and histological changes of the reconstructed tongue defect by rectus abdominis musculoperitoneal flap of dogs with or without nerve.

METHODS

12 Beagle dogs were randomly divided into two groups. Group A made rectus abdominis musculoperitoneal flap with the intercostal nerve while group B without the intercostal nerve. Nerve anastomosis was performed in Group A while not in Group B in the repairment. 12 weeks later, the length, width, surface area and cellular morphology and histological changes of the two transfer flaps were observed.

RESULTS

The length, width, surface area of transplanted rectus abdominis musculoperitoneal flaps in group A were greater than those in Group B, and the differences were statistically significant at 12th week (P < 0.01). The microscope study found that the transplanted rectus abdominis musculoperitoneal flaps of group A had part of muscle fiber atrophy with some connective and adipose tissue, loose muscle fiber arrangement, while the transplanted rectus abdominis musculoperitoneal flaps of Group B had muscle cells atrophy with some adipocyte. The structure of muscle cells in Group A was basically normal, but it was disorder in Group B. The type II muscle fibers of Group B was atrophy and substituted by a lot of connective tissue.

CONCLUSION

After tongue defect reconstructed by rectus abdominis musculoperitoneal flap with nerve, the changes of muscle fibers could be similar to tongue muscles, providing a basis for the dynamic recovery of the tongue.

Soccer attenuates the asymmetry of rectus abdominis muscle observed in non-athletes

Purpose

To determine the volume and degree of asymmetry of the rectus abdominis muscle (RA) in professional soccer players.

Methods

The volume of the RA was determined using magnetic resonance imaging (MRI) in 15 professional male soccer players and 6 non-active male control subjects.

Results

Soccer players had 26% greater RA volume than controls (P<0.05), due to hypertrophy of both the dominant (28% greater volume, P<0.05) and non-dominant (25% greater volume, P<0.01) sides, after adjusting for age, length of the RA muscle and body mass index (BMI) as covariates. Total volume of the dominant side was similar to the contralateral in soccer players (P = 0.42) and in controls (P = 0.75) (Dominant/non-dominant = 0.99, in both groups). Segmental analysis showed a progressive increase in the degree of side-to-side asymmetry from the first lumbar disc to the pubic symphysis in soccer players (r = 0.80, P<0.05) and in controls (r = 0.75, P<0.05). The slope of the relationship was lower in soccer players, although this trend was not statistically significant (P = 0.14).

Conclusions

Professional soccer is associated with marked hypertrophy of the rectus abdominis muscle, which achieves a volume that is 26% greater than in non-active controls. Soccer induces the hypertrophy of the non-dominant side in proximal regions and the dominant side in regions closer to pubic symphysis, which attenuates the pattern of asymmetry of rectus abdominis observed in non-active population. It remains to be determined whether the hypertrophy of rectus abdominis in soccer players modifies the risk of injury.

Large asymmetric hypertrophy of rectus abdominis muscle in professional tennis players

PURPOSE

To determine the volume and degree of asymmetry of the musculus rectus abdominis (RA) in professional tennis players.

METHODS

The volume of the RA was determined using magnetic resonance imaging (MRI) in 8 professional male tennis players and 6 non-active male control subjects.

RESULTS

Tennis players had 58% greater RA volume than controls (P = 0.01), due to hypertrophy of both the dominant (34% greater volume, P = 0.02) and non-dominant (82% greater volume, P = 0.01) sides, after accounting for age, the length of the RA muscle and body mass index (BMI) as covariates. In tennis players, there was a marked asymmetry in the development of the RA, which volume was 35% greater in the non-dominant compared to the dominant side (P<0.001). In contrast, no side-to-side difference in RA volume was observed in the controls (P = 0.75). The degree of side-to-side asymmetry increased linearly from the first lumbar disc to the pubic symphysis (r = 0.97, P<0.001).

CONCLUSIONS

Professional tennis is associated with marked hypertrophy of the musculus rectus abdominis, which achieves a volume that is 58% greater than in non-active controls. Rectus abdominis hypertrophy is more marked in the non-dominant than in the dominant side, particularly in the more distal regions. Our study supports the concept that humans can differentially recruit both rectus abdominis but also the upper and lower regions of each muscle. It remains to be determined if this disequilibrium raises the risk of injury.

Postpartum characteristics of rectus abdominis on ultrasound imaging

This cross-sectional and partial longitudinal study aimed to characterize changes in rectus abdominis (RA) and provide reference ranges for the first year postpartum. Ultrasound scanning was used at four stages postnatally to measure cross-sectional area (CSA), thickness, width (indirectly using a shape value) and inter-recti distance (IRD). One hundred and fifteen postnatal women (though some postnatal subjects appeared in more than one postnatal group thus giving a total of 183 data points) and 69 age-matched nulliparous female controls were recruited. Postnatal subjects were studied at Day 1 (PN1; n=63) and at 2 (PN2; n=55), 6 (PN3; n=39) and 12 (PN4; n=26) months postpartum. Longitudinal data were analysed for CSA, thickness, shape (indirect width measurement) (df=67) and IRD (df=62). The mean CSA of the PN1 group was significantly larger (P<0.001) than in controls and decreased (P<0.0021) by 12 months. In all postnatal groups, RA was significantly thinner (P<0.0001, PN1-PN3; P<0.0478, PN4), wider (P<0.0001, PN1-PN3; P=0.0326, PN4) and the IRD was significantly larger (P<0.0001, PN1-PN4) than in controls. Over 2 months postpartum, RA became thicker (P=0.0003) and the width and IRD decreased (P<0.0001 and P=0.0002, respectively) but did not return to control values by 12 months. These results have implications for strength of RA postpartum and anterior abdominal wall stiffness, which together with other muscle characteristics could inform development of effective postnatal exercise programmes.

Surgical correction of a buried penis focusing on the mons as an anatomic unit

A 54-year-old man with a severely concealed penis secondary to progressive obesity is presented. Circumferential adhesion release of the penis and monsplasty using bilateral elliptical excisions and suction-assisted lipectomy were carried out to restore shaft length. Specifically addressing the mons as an anatomic unit requiring defatting for adequate penile projection, as is described in this case report, has not been previously reported in the literature.

Tensile strength of the posterior and anterior layer of the rectus abdominis muscle sheath in cadavers

PURPOSE: The aim of the present study was to assess, in cadavers, the resistance to medial traction of the posterior and anterior layer of the rectus abdominis muscle sheath. METHODS: An anatomical, prospective, self-controlled study was carried out in 20 male cadavers. An evaluation of the tension of the posterior and anterior layers of the rectus abdominis muscle sheath was performed following anatomical dissection of these structures. The traction necessary to advance the tissue ten millimeters was assessed using an analogic dynamometer. RESULTS: There was no significant statistical difference between the necessary traction at various levels of the anterior and posterior layers of the rectus sheath. However, medial advancement of the anterior layer of the rectus sheath required more traction strength than did advancement of the posterior layer to the midline. CONCLUSION: There is no difference in the tensile strength in the various levels of the anterior and posterior layers of the rectus sheath; however, medial advancement of the the anterior layer required more traction strength.

Anatomical study of innervated transverse rectus abdominis musculocutaneous and deep inferior epigastric perforator flaps

The present study investigated anterior cutaneous branches of the 10th, 11th and 12th intercostal nerves. Innervated transverse rectus abdominis musculocutaneous (TRAM) flap and deep inferior epigastric perforator (DIEP) flap are often used in breast reconstruction. To innervate these flaps effectively, the appropriate anterior cutaneous branches of intercostal nerves must be selected. Dissection of 40 sides of 20 cadavers (5 male, 15 female) was performed. Nerves were classified into four groups according to vertical location from rectus abdominis (RA) entry points. Group 1 was situated from 0-19% of the umbilicus-to-pubic tubercle distance; Group 2, 20-39%; Group 3, 40-59%; and Group 4, 60-79%. Mean number of nerves per side was 1.4 in Group 1, 1.2 in Group 2, 1.1 in Group 3 and 0.2 in Group 4. The arcuate line was situated 32 +/- 9% below the umbilicus. Group 3 and 4 nerves tended to enter the RA more laterally than Group 1 nerves. Most nerves separated into 1-2 cutaneous branches while branching off several muscular branches. Several nerves in Groups 1 and 2 displayed no cutaneous branches. More muscular branches were present in Groups 1 and 2 than in Groups 3 and 4. Distance from lateral edge of the RA sheath to RA entry point was longer in Groups 1 and 2 than in Group 4. Cutaneous points, indicating entry points of a nerve into the dermis, were situated slightly more inferior than RA entry points. To innervate flaps effectively, a nerve entering the RA slightly superior to the expected sensory recovery area should be chosen. Clinically, Group 1 or 2 nerves seem to be selected in many TRAM or DIEP flap cases. If the cutaneous branch in Group 3 or 4 is easy to separate from RA, this can be included in the flap along with a main nerve, and might enable the flap to recover sensation in a wider area or reinforce the occasional lack of a sensory branch from Group 1 or 2. The present findings provide the basis for more precise dissection of TRAM and DIEP flaps, and should facilitate reliable preservation of sensation in flaps.

[The transverse rectus abdominis muscle (TRAM) flap. A "second defensive line" in microvascular reconstructions of defects in the head and neck area]

BACKGROUND

The microvascular anastomosed transverse rectus abdominis muscle (TRAM) island flap has been successfully used in plastic surgery for more than 10 years. In reconstructive head and neck surgery, however, it is not yet established.

METHOD

We analysed the preparation and anatomical variation in TRAM flaps in an examination of eight cadavers. In a clinical case with complete reconstruction of the nose after nasal ablation and complete loss of a radial lower forearm flap that had been transplanted previously due to a recurrent tumor, the possibility of forming and modeling a TRAM flap is demonstrated.

RESULTS

The flap vessels of the TRAM are comparable to the radial forearm flap, and the donor site may be primarily closed. The TRAM proved to be a suitable alternative to close lesions of the head and neck area in selected cases. The myocutaneous TRAM is bulkier than the fascio-cutaneous radial forearm flap. The subcutaneous abdominal fat of the TRAM can be reduced in relation to the vascular distribution of the perforator vessels. If the subcutaneous fat of the flap is reduced, the flap can be shaped and formed well. In the described case, it was used to close the lesion after ablation of the nose and middle face.

CONCLUSION

The risk of an iatrogenic lesion of the peritoneal fascia or postsurgical herniation of the abdominal wall is low if several surgical prerequisites are taken into consideration. The myocutaneous TRAM will not replace the fascio-cutaneous radial forearm flap in microvascular head and neck surgery, but the large diameter of the donor vessels and the highly vascularized flap tissue makes it an alternative as a second line procedure in cases of unfavorable wound conditions.

[Anatomic study and advantages of the free rectus abdominis flap for head and neck reconstruction]

INTRODUCTION

The main goal of using the free flap is to be able to carry out extensive surgical resection resulting in good functional outcome. The aims of this study were to define the best area for free rectus abdominis harvest and to assess its value in head and neck reconstruction.

MATERIAL AND METHODS

Twenty rectus abdominis flaps were studied in ten fresh cadavers. A review of the literature of the free rectus abdominis flap in head and neck reconstruction yielded the main recipient sites and complications (flap necrosis and postoperative abdominal hernia). A reconstruction was performed after near total glossectomy.

RESULTS

With seven perforators and four cutaneous branches of intercostal nerves, the paraumbilical region is the best area to harvest this flap. The rectus abdominis free flap seems to be adapted for near total glossectomy reconstruction. Previous studies reported that this flap was essentially used for oropharynx and skull base reconstruction. The main complications are flap necrosis (4%) and abdominal hernia (3%).

CONCLUSION

The paraumbilical rectus abdominis free flap is reliable and easy to use with a two-team approach in head and neck reconstruction with moderate donor site morbidity. It is useful for reconstruction of large defects of the oropharynx and skull base. Sensory-motor reinnervation superiority for deglutition in tongue reconstruction still needs to be evaluated.

Anatomic and Clinical Study of Rectus Abdominis Musculocutaneous Flaps Based on the Superior Epigastric System

This anatomic and clinical study supports the use of the ipsilateral transverse rectus abdominis musculocutaneous (TRAM) flap over the contralateral TRAM flap for breast reconstruction. The costomarginal artery was constant in these dissections and supplied a vascular pedicle to the rectus abdominis muscle. Radiologic studies confirmed the communications between the costomarginal artery and the deep epigastric system, the same as between the costomarginal artery and the musculophrenic and intercostal arteries. The results of the clinical series confirmed the costomarginal artery as an alternative or adjuvant vascular pedicle of the deep superior epigastric artery in cases of potential lesion of the latter. The lack of pedicle tension because of the shorter distance to be transposed allowed a greater versatility in flap shaping and positively affected its aesthetic result. This fact made the authors change from the contralateral to the ipsilateral pedicled TRAM flap as the first option for autologous breast reconstruction because of vascular security.

Sagittal plane moment arms of the female lumbar region rectus abdominis in an upright neutral torso posture

BACKGROUND

Prior imaging studies of torso muscle moment arms for use as inputs into biomechanical models have been derived from subjects lying supine. Recent research suggests moment arms of the rectus abdominis are larger when standing versus lying supine.

METHODS

Axial MRI images, through and parallel to the intervertebral discs were obtained from five females in a standing upright neutral posture. Digitizing software was utilized to quantify the distance in the sagittal plane between the centroids of the intervertebral disc and the rectus abdominis muscle, and converted to the transverse plane to allow comparisons with studies with subjects in a supine posture.

FINDINGS

The mean sagittal plane moment arms in the transverse plane were 9.7, 9.1, 8.5, 8.5 and 9.8 cm at the L(1)/L(2), L(2)/L(3), L(3)/L(4), L(4)/L(5) and L(5)/S(1) intervertebral levels, respectively. Compared with a study on females of a similar age group, the moment arms from this study were larger at each level, increasing from 7.3% larger at L(1)/L(2) to 43.7% larger at L(5)/S(1).

INTERPRETATION

Accurate anatomical geometrical representation in biomechanical models is necessary for valid estimates of internal loading. Sagittal plane rectus abdominis moment arms were larger from the upright neutral torso posture in this study compared to studies with subjects lying supine. This suggests the torso internal moment generating capability would be represented differently in biomechanical models that use data from studies where subjects were upright, which is more reflective of the postures biomechanical models are utilized for, than when using anatomical geometry derived from supine postures.

Technical consideration for subxiphoidal incisional hernia repair

BACKGROUND

The main principle of incisional hernia repair with mesh augmentation is a wide overlap of at least 5 cm in all directions. This is complicated when cartilaginous or osseous structures border the fascial defect, most notably at the xiphoid after sternotomy or in large proximal incisional hernias.

METHOD

We performed an anatomic investigation of this "problematic" area with its different structures and layers that form the retroxiphoidal space.

RESULTS AND CONCLUSION

The posterior lamina of the rectus sheath inserts on the posterior side of the xiphoid. This lamina inhibits a sufficient mesh placement. By sharp dissection dorsal the xiphoid process, the posterior lamina of the rectus sheath can be detached. This way the retroxiphoidal space can be opened. Further development of this space can be made by blunt dissection. In some cases, with retroxiphoidal scar formation after sternotomy, a sharp dissection might be necessary. This enables a combined retromuscular-retroxiphoid mesh augmentation repair with a sufficient underlay of at least 5 cm, according to the principles of sublay technique.

Clinical importance of unusual patterns of tendinous intersections of rectus abdominis muscle

The objective of the present study was to note the different patterns of tendinous intersections of rectus abdominis muscle and its surgical importance. The tendinous intersections of rectus abdominis muscle were studied in dissected 46 human cadavers dissected over a span of 3 years. Only two unusual patterns of intersections; one with tendinous intersections arched, and the other with the intersections at different levels on the right and left sides of the same cadaver, were observed, in two different cadavers. The tendinous intersections are the sites of anastomosis of numerous blood vessels. Surgeons using the the Transverse Rectus Abdominis (TRAM) flap in autogenous breast constructive surgeries should be aware of such unusual patterns so as to design the TRAM flap accordingly. Biomechanics of rectus abdominis muscle may also be influenced by arched pattern of tendinous intersections instead of normal transverse pattern.

Morphometrical study of the arterial perforators of the deep inferior epigastric perforator flap

Although abdominal perforator flaps based on a cutaneous branch of the deep inferior epigastric artery (DIEP flaps) have many advantages, preparing these flaps is technically difficult and requires great skill, especially as the portion of the artery running under the anterior rectus abdominis sheath must be operated upon "blind". To allow easier preparation and elevation of a DIEP flap pedicle, we propose that the arterial perforator should: 1) be more than 1.0 mm large; 2) run a straight intramuscular course, parallel to the rectus abdominis m. fibers, with no large muscular branches; and 3) have only a short portion running immediately under the anterior rectus abdominis sheath. We examined 329 perforators (more than 0.5 mm in diameter at the anterior sheath) in 66 rectus abdominis mm. from 33 cadavers among them: 1) 52 "large" perforators were over 1.0 mm in diameter; 2) 107 "suitable" perforators ran parallel to the muscle fibers without giving off large muscular branches; and 3) 35 "ideal" perforators combined these characteristics. The ideal perforators were usually located in the mid-abdominal region, 10-30 mm lateral to the umbilicus. The suitable perforators were usually present, often in combination with the ideal perforator(s), in a restricted area 20 mm cranial and 40-50 mm lateral to the umbilicus. We classified the course and ramification pattern of the deep inferior epigastric a. into six patterns, depending on whether the anastomosis was sited in the medial or lateral branch and the level at which the branches originated.

Perforator topography of the deep inferior epigastric perforator flap in 100 cases of breast reconstruction

The anatomic topography of the perforators within the rectus muscle and the anterior fascia largely determines the time needed to harvest the perforator free flap and the difficulty of the procedure. In 100 consecutive cases, the topographic patterns of the perforators were investigated. In 65 percent, a short intramuscular course was seen. In 16 percent, a perforator at the tendinous intersection was encountered. In 9 percent, the largest perforator was found to have a long intramuscular course. In 5 percent, a subfascial course was found, and in another 5 percent, a paramedian course was found. In 74 percent of flaps, just one perforator was used, whereas two perforators were dissected in 20 percent. Only in 6 percent of flaps were three perforators used. A long intramuscular course (>4 cm) lengthens the dissection substantially, especially when the intramuscular course is in a step-wise pattern. The subfascial course requires precarious attention at the early stage of the perforator dissection when splitting the fascia. The perforators at the tendinous intersections are the most accessible and require a short but intense dissection in the fibrotic tissue of intersection. A paramedian perforator, medial to the rectus muscle, is a septocutaneous rather than a musculocutaneous perforator. The straightforward dissection almost extends up to the midline. Therefore, dissection always is performed at one side and, if no good perforators are present, continued at the intact contralateral side. The size of these perforators and their location in the flap determine the choice. One perforator with significant flow can perfuse the whole flap. If in doubt, two perforators can be harvested, especially if they show a linear anatomy so that muscle fibers can be split. The only interference with the muscle exists in splitting the muscle fibers. A perforator that lies in the middle of the flap is preferable. For a large flap, a perforator of the medial row provides better perfusion to zone 4 than one of the lateral row because of the extra choke vessel for the lateral row perforators. The clinical appearance of the perforators is the key element in the dissection of the perforator flap. Perforator topography determines the overall length and difficulty of the procedure.

Role of the anterolateral thigh flap in head and neck reconstruction: advantages of moderate skin and subcutaneous thickness

Skin-flap thickness is an important consideration when choosing a free flap for head and neck reconstruction. The anterolateral thigh flap, the rectus abdominis flap, and the radial forearm flap, which included the epidermis, the dermal, and the subcutaneous layers, were measured using ultrasonography in 31 patients. The mean skin and subcutaneous thickness of the anterolateral thigh flap was 7.1 mm; the rectus abdominis flap was 13.7 mm; and the radial forearm flap was 2.1 mm. Further analysis revealed a statistically significant difference among the skin and subcutaneous thickness of the three flap groups. Of the 44 anterolateral thigh flap transfers done for head and neck reconstruction after cancer ablative surgery, 41 (93.2 percent) were transferred successfully. The anterolateral thigh flap creates a moderately thick skin flap, and is less variable in thickness across its area than is the rectus abdominis flap. The flap is adaptable for reconstruction of head and neck soft-tissue defects.

Comparison of a new method for computer analysis with standard techniques for measuring survival rates in the rat transverse rectus abdominis musculocutaneous flap

Many methods have been used to measure experimental flap survival in animal models. These have previously included planimetry, computer programs, and (routinely by the authors) the simple measurement of the weight of a template traced according to the dimensions of a given flap. To test the validity of their method, an alternative technique was developed by the authors' biostatiticians. Initially, in a study of rat transverse rectus abdominis musculocutaneous (TRAM) flaps, all templates were also scanned electronically to form bitmaps. Using commonly available software programs, each bitmap was colorized corresponding to viable and nonviable areas of the flaps. A summation of individual pixels by color could then be used to calculate the percentage of flap survival. A comparison of both methodologies in 64 rat TRAM flaps found that the survival rate was slightly greater overall when a computer analysis had been performed (3.1 +/- 1.7%), but this was not a significant difference (p = 0.479). Thus, the previous standard method was proven reliable, but just as precise calculations are now possible using the convenience of any personal computer.

Measurement of the volume of the pedicled TRAM flap in immediate breast reconstruction

The transverse rectus abdominis musculocutaneous (TRAM) flap is now accepted as the standard for breast reconstruction, but achieving symmetrical breast reconstruction is still a challenge. A precise estimate of the volume of the flap is necessary to reconstruct a symmetrical and aesthetically pleasing breast. Many methods have been developed to overcome this problem, but they have not been suitable for the pedicled TRAM flap. By using a self-made device based on the Archimedes' principle, the authors can calculate accurately the volume of the pedicled TRAM flap and predict reliably the breast volume intraoperatively. The "procedure" is based on a self-made box into which the pedicled TRAM flap is placed. Warm saline is added to the box and the flap is then removed. Flap volume is calculated easily by determining the difference between the preestimated volume of the box and the volume of the residual water. From February to May 2000, this method was used on 28 patients to predict breast volume for breast reconstruction. This study revealed that the difference of the maximal chest circumferences (the index of the breast volume) demonstrates a positive correlation with the difference of the volumes and weights between the mastectomy specimen and the net TRAM flap. However, a more closely positive correlation exists between the differences of maximal chest circumference volume (r = 0.677) than maximal chest circumference weight (r = 0.618). These data reveal that the reconstructed breast's volume has a closer relationship with the volume of the net pedicled TRAM flap, rather than with its weight.

Architecture of the rectus abdominis, quadratus lumborum, and erector spinae

Quantitative descriptions of muscle architecture are needed to characterize the force-generating capabilities of muscles. This study reports the architecture of three major trunk muscles: the rectus abdominis, quadratus lumborum, and three columns of the erector spinae (spinalis thoracis, longissimus thoracis and iliocostalis lumborum). Musculotendon lengths, muscle lengths, fascicle lengths, sarcomere lengths, pennation angles, and muscle masses were measured in five cadavers. Optimal fascicle lengths (the fascicle length at which the muscle generates maximum force) and physiologic cross-sectional areas (the ratio of muscle volume to optimal fascicle length) were computed from these measurements. The rectus abdominis had the longest fascicles of the muscles studied, with a mean (S.D.) optimal fascicle length of 28.3 (4.2)cm. The three columns of the erector spinae had mean optimal fascicle lengths that ranged from 6.4 (0.6)cm in the spinalis thoracis to 14.2 (2.1)cm in the iliocostalis lumborum. The proximal portion of the quadratus lumborum had a mean optimal fascicle length of 8.5 (1.5)cm and the distal segment of this muscle had a mean optimal fascicle length of 5.6 (0.9)cm. The physiologic cross-sectional area of the rectus abdominis was 2.6 (0.9)cm(2), the combined physiologic cross-sectional area of the erector spinae was 11.6 (1.8)cm(2), and the physiologic cross-sectional area of the quadratus lumborum was 2.8 (0.5)cm(2). These data provide the basis for estimation of the force-generating potential of these muscles.

[Applied anatomy of the transverse rectus abdominis musculocutaneous (TRAM) flap in relation to the eleventh or twelfth thoracic nerve]

OBJECTIVE

To observe the distribution of the terminal branches of the eleventh and twelfth thoracic nerve(T11, T12) for the anatomical basis and operation key points of the transverse rectus abdominis musculocutaneous(TRAM) flap with T11, T12.

METHODS

The anterior abdominal wall was investigated through anatomical dissection in 22 embalmed cadavers.

RESULTS

Cutaneous nerve distribution in the TRAM flap came mainly from T11, T12. They run obliquely between transverse abdominis and obliquus internus abdominis muscle. At the lateral edge of the rectus abdominis, they piece the anterior rectus sheath into the muscle. While supplying the muscle they pass on to supply the anterior rectus sheath and the overlying skin.

CONCLUSION

It is possible to preserve T11, T12 in the TRAM flap, which would favour rapid return of flap sensation.

Laparoscopic extraperitoneal inguinal hernia repair. A safe approach based on the understanding of rectus sheath anatomy

We have devised a reproducible approach to the preperitoneal space for laparoscopic repair of inguinal hernias that is based on an understanding of the abdominal wall anatomy. Laparoscopic totally extraperitoneal herniorrhaphy was performed on 99 hernias in 90 patients at the Los Angeles County-University of Southern California Medical Center, using a standardized approach to the preperitoneal space. Operative times, morbidity, and recurrence rates were recorded prospectively. The median operative time was 37 min (range, 28-60) for unilateral hernias and 46 min (range, 35-73) for bilateral hernias. There were no conversions to open repair, and there was only one conversion to a laparoscopic transabdominal approach. Complications were limited to urinary retention in two patients, pneumoscrotum in one patient, and postoperative pain requiring a large dose of analgesics in one patient. All patients were discharged within 23 h. There were no recurrences or neuralgias on follow-up at 2 years. A standardized approach to the preperitoneal space based on a thorough understanding of the abdominal wall anatomy is essential to a satisfactory outcome in hernia repair.

Lumbar muscle force estimation using a subject-invariant 5-parameter EMG-based model

The use of electromyographic measures, in concert with modeled or empirical representations of muscle physiology, is a common approach for estimation of muscle force. Existing models of the lumbar musculature have allowed model parameters to vary for an individual subject. While this approach improves apparent predictive ability, it loses some degree of construct validity since parameter variability may not be physiologically justifiable. An EMG-based five-parameter model, adapted and generalized from earlier reports, is presented here. Inherent in the model is the requirement of subject-invariant modeling parameters. As a practical analysis tool was desired, the model relies on relatively few calibration constants whose determination is described. Empirical evaluation was undertaken using a database of 398 experimental trials involving lifting and transferring objects of moderate mass. Model performance, evaluated by comparison of measured and predicted lumbar moments, was comparable to earlier models, with r2 mean (S.D.) values of 0.76(0.15) for sagittal plane moments, and rms mean (S.D.) errors of 14.1(7.4), 9.7(5.3), and 8.6(3.6) Nm in the sagittal, frontal, and horizontal planes, respectively. These empirical results and the argument of physiological veracity support the use of a subject-invariant model.

Are recruitment patterns of the trunk musculature compatible with a synergy based on the maximization of endurance?

To verify that maximization of endurance is important among the functional criteria determining trunk muscle activation patterns, symmetric and asymmetric exertions were simulated using a detailed model consisting of 114 muscle slips crossing the lumbosacral junction and employing a cost function which maximizes endurance. First, the question whether meaningful comparisons can be made between activity predictions for individual muscle slips and surface EMG data recorded from larger anatomical entities was addressed. This was answered affirmatively, since activation patterns predicted by a coarse and a middle version of the model, in which activation was constrained to be equal within 14 or 32 groups of muscle slips, were similar to those predicted with each muscle slip controlled independently. Median correlation coefficients between activity vectors predicted by the simplified models and the detailed model were 0.88 and 0.97, respectively. The coarse model underestimated the endurance capacity by a median of 21%, the middle model by only 0.7%. Second, predicted activities within anatomical entities defined at this level of detail were compared to reference data derived from the literature (Lavender et al. 1992, Human Factors 34, 239-247; 1992, Journal of Orthopaedic Research 10, 691-700; Vink et al., 1988, Electromyography and Clinical Neurophysiology 28, 517-525). The predicted activity patterns of the erector spinae, external oblique and rectus abdominis muscles closely resembled the EMG patterns (r2 = 0.48-0.99). Furthermore, the observed distribution of activity between parts of the erector spinae muscle was adequately predicted.

What you see is what you get: lack of significant postoperative contour change in muscle transplants to the lower leg

A widely held tenet in the reconstructive surgery literature is that muscle transplants undergo significant postoperative atrophy, contributing to progressive improvement in appearance of the reconstruction. In contrast, it has been our experience that muscle transplants retain the majority of their bulk following inset, and undergo minimal postoperative atrophy. Prospective evaluation of 20 patients undergoing muscle transplant reconstruction of Gustillo type IIIB lower limb wounds found minimal decrease in limb circumference at 6-month follow-up, as measured at the point of maximum transplant projection.

Structure and function of the abdominal muscles in primigravid subjects during pregnancy and the immediate postbirth period

BACKGROUND AND PURPOSE

The purpose of this study was to investigate the abdominal muscle structural adaptations and functional capabilities during pregnancy and the postbirth period.

SUBJECTS

Six primigravid subjects, aged 28 to 33 years, participated in nine test sessions from 14 weeks of gestation to 8 weeks postbirth.

METHODS

At each test session, three-dimensional photography of abdominal skin markers was used to determine the gross morphology of a representative abdominal muscle, the rectus abdominis muscle. The functional capability of the abdominal muscle group was assessed on the ability of the muscle group to stabilize the pelvis against resistance.

RESULTS

Increases were found in rectus abdominis muscle separation width, length, and angles of insertion as pregnancy progressed. Reversal in rectus abdominis muscle separation was found by 4 weeks postbirth. The ability to stabilize the pelvis against resistance was shown to be decreased as pregnancy progressed and remained compromised postbirth. Decrements in abdominal muscle function paralleled in time the structural adaptations as pregnancy progressed. Continued functional deficits were found in parallel with incomplete resolution of structural adaptations postbirth.

CONCLUSION AND DISCUSSION

Abdominal muscle function is affected by structural adaptations that occur during pregnancy. Because our results showed that the ability to stabilize the pelvis against resistance is decreased during pregnancy and at least 8 weeks postbirth, abdominal muscle exercises should be chosen with care. [Gilleard WL, Brown JMM. Structure and function of the abdominal muscles in primigravid subjects during pregnancy and the immediate postbirth period.

Neutral and cationic amino acids in striated rectus muscle are generally in excess of those in smooth uterine muscle of term pregnant women

The concentrations of 24 amino acids and four other related compounds were determined in extracts of biopsy specimens from myometrium and musculus rectus abdominis of 10 healthy term pregnant women during elective cesarean sections. The total free amino acid pool did not differ significantly between the two muscle types. There was a myometrial abundance of the two anionic amino acids glutamate and aspartate and the two aromatic amino acids tyrosine and phenylalanine, but most neutral and cationic amino acids in striated skeletal muscle tissue were found in excess of those in uterine muscle tissue.

The sensate deep inferior epigastric musculocutaneous flap and the twelfth thoracic nerve

A detailed anatomical study of the terminal branches of the twelfth thoracic nerve (subcostal nerve) based on observations made during dissections of 23 embalmed cadavers is presented. In all 23 cadavers, the twelfth thoracic nerve had an ascending branch which joined the deep inferior epigastric vascular pedicle about half way between the lower border of the umbilicus and the symphysis pubis. This observation, we believe, explains how it is possible to preserve sensation in the deep inferior epigastric musculocutaneous flap.

Physiologic superiority of the anatomic dominant pedicle of the TRAM flap in a rat model

Despite an extensive knowledge of the anatomic nuances of the rectus abdominis muscle and corresponding relationship to the vascularization of the skin of the abdomen, the clinical outcome when used as a musculocutaneous flap cannot always be predictable. Only a few human physiologic studies have been attempted to explain this discrepancy. Further laboratory investigations of the anatomy and physiology of the rat transverse rectus abdominis musculocutaneous (TRAM) flap suggest that this is a safer, comparable, yet inexpensive animal model for studying further the dynamics of this flap. By caliber and course, the major source vessel to the rectus abdominis muscle in the Sprague-Dawley rat enters superiorly as the cranial epigastric artery, which is a continuation of the internal thoracic (mammary) artery. Anatomic dissections in 13 rats revealed, on average, that 4.7 +/- 0.97 large musculocutaneous perforators emanated from each cranial epigastric artery at regular intervals which then proceeded directly to the overlying abdominal integument. Just below the umbilicus, a watershed is formed by small "choke" anastomoses to a frequently vestigial caudal epigastric artery or, more commonly, a true anastomosis with a branch of the deep circumflex iliac artery. In 10 additional rats, TRAM flaps encompassing the skin of the entire abdominal wall were then elevated so as to rely on a single pedicle, alternating randomly from either source. By laser Doppler flowmetry, blood flow by means of the larger-caliber superior pedicle exceeded twice that of the subservient inferior pedicle.(ABSTRACT TRUNCATED AT 250 WORDS)

The location of abdominal wall blood vessels in relationship to abdominal landmarks apparent at laparoscopy

OBJECTIVE

Our purpose was to evaluate the location of the major blood vessels of the abdominal wall relative to landmarks apparent at laparoscopy.

STUDY DESIGN

Abdominal computed tomographic images of 21 reproductive-aged women at an academic center were retrospectively reviewed to determine the location of the inferior epigastric, superficial epigastric, and superficial circumflex iliac arteries and the lateral rectus muscle margins in relation to the symphysis pubis, the umbilicus, and the abdominal midline. These locations were correlated with each other and with body mass index using Pearson's correlation coefficient.

RESULTS

Above the symphysis the inferior and superficial epigastric arteries were 5.6 +/- 1.0 cm (mean +/- SD) and 5.5 +/- 2.0 cm from the midline, respectively. Although the location of these two vessels correlated (r = 0.6, p = 0.02), the mean difference in their location was 1.4 +/- 1.1 cm. Near the level of the umbilicus the superficial epigastric and circumflex iliac arteries and the lateral rectus muscle margin were 4.6 +/- 1.4 cm, 10.7 +/- 1.7 cm, and 7.6 +/- 1.5 from the midline, respectively. Only the lateral rectus muscle margin correlated with body mass index (r = 0.65, p = 0.004).

CONCLUSION

When laparoscopic landmarks are not visible to guide placement, lateral trocars should be placed approximately 8 cm from the midline and at least 5 cm above the symphysis to minimize the risk of vessel injury.

Abdominal-wall reconstruction with expanded musculofascial tissue in a posttraumatic defect

An anatomic basis for expansion of the abdominal wall is presented and clinically demonstrated in an adult man with a posttraumatic defect. The patient demonstrates an intact, functional abdominal wall 4 years after the procedure. The procedure provides autogenous, innervated, well-vascularized, contractile tissue for repair of abdominal-wall hernias. Large tissue expanders are placed between the external oblique and internal oblique muscles. A small incision in the posterior rectus sheath is made in order to gain access to the potential space between these muscles. The incision in the posterior rectus sheath is kept small to minimize risk of denervation of the rectus abdominis muscle. Tissue expansion is carried out over several weeks. After removal of the expanders, abundant musculofascial tissue is available for reconstruction of the abdominal wall. The abdominal wall is then reconstructed with innervated, functioning tissue.

Sonographic anatomy of the rectus sheath: an indication for new terminology and implications for rectus flaps

With the aim of standardizing descriptions of lesions on the anterior abdominal wall and definition of reconstructive flaps, the sonographic anatomy of the rectus sheath has been studied in 8 subjects. Anatomic terms have been suggested for the various segments and intersections of the sheath. The linea abla, linea semilunaris, formation of rectus sheath, segments and intersections have been described and illustrated. Identical segments and intersections were found to have characteristic sonographic features in all subjects. The intersection below the umbilicus was observed in 1 out of 8. Ultrasound capability in the determination of size and extent of tissues is discussed. It is hoped that the use of the suggested terminology and the preoperative ultrasonic definition of rectus flaps, may provide basis for objective comparison of results of reconstructive surgery.

Type, diameter and distribution of fibres in some respiratory and abdominal muscles of the goat

This study was designed to determine the histochemical properties, size and composition of fibres in the diaphragm, intercostal and abdominal muscles of goats to clarify whether reported similarities in respiratory muscle physiology between goats and humans have a structural basis. Serial sections (10 microns) of muscular tissue from adult female goats were stained for myosin adenosine triphosphatase and reduced nicotinamide adenine dinucleotide dehydrogenase-tetrazolium reductase activities; the fibres were classified into type I, IIA and IIB; and their mean diameter and composition were determined. Abdominal and intercostal muscles contained types I, IIA and IIB fibres in the ratio 1:1:1, and the mean diameter of the fibres ranged from 49.2 to 62.2 microns. In contrast, the diaphragm contained 58.9% type I and 41.1% type II fibres, and the latter could not be differentiated into types IIA and IIB. Diaphragmatic fibres were also smaller (36.9-40.9 microns). These findings contrast with those in humans, where the diaphragm, intercostal and abdominal muscles contain > 50% type I fibres and have fibres of identical diameter. The differences in fibre characteristics between the diaphragm, intercostal and abdominal muscles of goats and the differences between goats and humans need to be taken into consideration in interpreting the results from studies in respiratory muscle physiology.