A fluoroscopic analysis of the length changes of the capsulo-osseous layer of the distal iliotibial band.

PURPOSE: Previous studies have implicated the iliotibial band and its deeper capsulo-osseous layer as key restraints against internal rotation. However, the kinematic properties of the capsulo-osseous layer, throughout knee range of motion, are not currently known. Therefore, the purpose of this research was to quantify the length changes of this structure through various degrees of knee flexion. METHODS: Ten cadaveric knee specimens were dissected to expose the capsulo-osseous layer of the iliotibial band. Radiopaque beads were embedded, at standardized increments, into the tissue and fluoroscopic images were taken from 0° to 105° of knee flexion in 15° increments. The positions of the beads were identified in each image and the length, width, and area changes of the capsulo-osseous layer were calculated. The data were analyzed as a percent change from 0° and compared across flexion angles using a repeated-measures analysis of variance (α = 0.05). RESULTS: There was a significant increase in the length of the capsulo-osseous layer at flexion angles greater than 30°, with changes occurring primarily at the level of the femoral insertion. Meanwhile, non-homogenous decreases in width and area were found with increasing flexion angle. The distance between the capsulo-osseous layer insertion on the distal femur and proximal tibia significantly increased from 60° to 105°; maximal changes occurred at 105° [9.64 (4.12) %, p = 0.003]. CONCLUSIONS: The capsulo-osseous layer of the iliotibial band behaves in a non-isometric fashion and this work suggests that tensioning and fixation should occur between 75° and 105° of flexion, if repair or reconstruction is indicated.

[The plasty for the hip region sores, using the flap, consisting of M. tensor fasciae latae].

The method of plasty for the hip region sores, based on transposition of proximal part of m. tensor fascia latae in content of the flap, using her transsection between place of attachment to spina iliaca anterior superior and place of the main vascular pedicle entry into the muscle, was proposed, what permits to prevent vast mobilization of the muscle and to secure existing in normal conditions and formed in pathological conditions anas- tomoses between vascular net of the flap and surrounding tissues. The method proposed was successfully applied for plasty of the hip region sores of degrees III-IV in 2 patients.

A comparison of diced cartilage grafts wrapped in perichondrium versus fascia.

UNLABELLED: Cartilage grafts are the most commonly used grafts for structural and aesthetic purposes. This study aimed to compare the viability of diced cartilage grafts wrapped in fascia with diced cartilage grafts wrapped in perichondrium. Approximately 2 × 2 cm cartilage grafts were harvested from the ears of seven New Zealand rabbits, diced to approximately 1-mm cubes, and then wrapped in perichondrium harvested from the ears or muscle fascia harvested from the right rear leg of the same rabbits. The wrapped grafts were then weighed and implanted into two paravertebral subcutaneous cavities created on the shaved backs of the donor rabbits. After 3 months, the rabbits were sacrificed and the grafts were removed, weighed and examined histopathologically. We found no statistically significant difference in the weights of the two graft types before and after embedding. The mean chondrocyte viability was 87.14 % in the perichondrium-wrapped cartilage grafts and 41.43 % in the fascia-wrapped grafts, which was determined to be statistically significant. Overall, our findings show that cartilage grafts wrapped in perichondrium led to higher chondrocyte viability and graft survival rates as compared with grafts wrapped in fascia. This method may be used as an alternative in clinical practice to provide patients requiring cartilage grafts with positive long-term effects, lower morbidity and lower costs associated with the procedure. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Time dependent variations in biomechanical properties of cadaveric fascia, porcine dermis, porcine small intestine submucosa, polypropylene mesh and autologous fascia in the rabbit model: implications for sling surgery.

PURPOSE: We investigated time dependent variations in tensile strength, stiffness, shrinkage and distortion in 6 materials commonly used for transvaginal anti-incontinence surgery. MATERIALS AND METHODS: A total of 15 rabbits were randomized into 3 survival groups (2, 6 and 12 weeks, respectively). Each rabbit had human cadaveric fascia, porcine dermis, porcine small intestine submucosa, polypropylene mesh and autologous fascia implanted on the anterior rectus fascia. At harvest tensiometry and image analysis were performed on each sling. Results were compared to baseline for each sling type and the percent decrease from baseline was compared among sling types. RESULTS: Each type of human cadaveric fascia and porcine allografts showed a marked decrease (60% to 89%) in tensile strength and stiffness from baseline. Polypropylene mesh and autologous fascia did not differ in tensile strength from baseline. Polypropylene mesh increased in stiffness from baseline. Autologous fascia and small intestinal submucosa demonstrated a 41% and 50% decrease in surface area, respectively, at 12 weeks. CONCLUSIONS: To our knowledge the relative contribution of biomechanical properties of sling material to the success of anti-incontinence surgery is unknown. However, rapid loss of tensile strength and stiffness in porcine and cadaveric materials may contribute to the early re-emergence of symptoms following successful sling surgery. The results of this study add scientific validity to the increasing use of synthetics in anti-incontinence surgery. Urologists selecting a sling material should be aware of its time dependent biomechanical fate relative to other sling materials.

Donor fascia in urogynaecological procedures: a canine model.

OBJECTIVE: To explore the in vivo characteristics of donor fascia used in urogynaecological procedures, in a canine model. MATERIALS AND METHODS: Two experiments were conducted. In the first, donor fascia grafts were obtained from 12 dogs, the grafts freeze-dried and half were irradiated. The grafts were used for sacrocolpopexy and suburethral slings in each of five dogs. The dogs were killed at 2, 6 and 12 weeks after graft implantation, the grafts retrieved and assessed using tensilometry. In the second experiment, unirradiated sacrocolpopexy grafts were implanted in eight dogs; four grafts were placed under no tension and four under moderate tension. At 8 weeks, the grafts were retrieved and assessed by tensilometry. Measures of strength in both experiments included the ultimate tensile strength, ultimate strain and stiffness. All measures were compared using Kruskal-Wallis nonparametric tests in both studies. RESULTS: In the first experiment, a significant minority (23%) of grafts had complete loss of strength. Measures of graft strength did not vary when analysed according to donor dog, host dog, history of graft irradiation, duration of implantation or location of graft. In the second experiment, grafts placed under no tension tended to have lower tensile strength (chi2(1) = 3.125, P = 0.077), lower stiffness (chi2(1) = 3.125, P = 0.077) and lower ultimate strain (chi 2(1) = 3.182, P = 0.074). CONCLUSION: Graft irradiation as an isolated variable did not predispose grafts to failure in vivo. Biomechanical factors at the implantation site are likely to play a critical role in determining ultimate graft strength.

Tensile strength of cadaveric fascia lata compared to small intestinal submucosa using suture pull through analysis.

PURPOSE: The modified pubovaginal sling has become popular as first line treatment for stress urinary incontinence. With the increasing use of cadaveric fascia as a sling material, widespread shortages are prevalent, hence limiting its availability. The increased morbidity with the use of synthetic sling materials and autologous fascia has stimulated investigation of other sling materials. We evaluated the tensile strength of 4 suture types, and compared tensile strength of cadaveric fascia lata to porcine small intestinal submucosa using suture pull through analysis to assess their efficacy and durability for use in anti-incontinence procedures. MATERIALS AND METHODS: Suture breaking load was determined using 2 and 1-zero polypropylene suture, and 2 and 1-zero polyglactin suture. Freeze dried gamma irradiated human fascia lata and freeze-dried small intestinal submucosa were evaluated. Suture was fixed to sling material using the cross fold technique. Mean suture breakage and suture pull through were determined using a tensionometer by measuring the load applied to the sling/suture system. Statistical analysis was performed. RESULTS: Mean suture breakage load was greatest with 1-zero polyglactin (8.10 pounds) and least with 2-zero polypropylene (3.68 pounds). Mean suture breakage strength was similar for 1-zero polypropylene and 2-zero polyglactin at 5.26 and 5.40 pounds, respectively. Mean suture pull through load using 1-zero polypropylene suture and the cross fold technique was 5.64 pounds for cadaveric fascia and 2.74 pounds for small intestinal submucosa (p <0.0001). Maximum load was limited by the suture strength when using cadaveric fascia, whereas, maximum load was limited in small intestinal submucosa by its inherent tensile strength. However, using a new technique for suture fixation to the small intestinal submucosa, we were able to increase significantly mean suture pull through load to 3.36 pounds (p = 0.008). Additionally, with this new technique small intestinal submucosa allowed gross stretching before suture pull through that was not seen with cadaveric fascia. CONCLUSIONS: Despite the current standard use of 1-zero polypropylene suture for pubovaginal sling fixation, our data suggest that 1-zero polyglactin suture is the strongest, and its use with pubovaginal sling fixation warrants further investigation. Using the cross fold technique and 1-zero polypropylene suture, tensile strength was greatest with cadaveric fascia compared to small intestinal submucosa. Although small intestinal submucosa was not as strong as cadaveric fascia, our persuasive preliminary data suggest that further investigation is warranted in the use of small intestinal submucosa and other suture fixation techniques, and its observed stretch capacity. Hence, with further studies small intestinal submucosa may remain a viable option for pubovaginal sling material.

Use of small intestinal submucosal implants for regeneration of large fascial defects: an experimental study in dogs.

A single layer of porcine small intestinal submucosa (SIS) was sutured into a 5 x 5 cm window created in the fascia lata of ten adult mongrel dogs in order to determine the efficacy of this material in promoting tissue regeneration of large fascial defects. A similar defect in the contralateral limb was left empty and served as a negative control. Tissue regeneration was examined grossly and histologically at 6 and 12 weeks. By 6 weeks, marked fibroplasia and angiogenesis had occurred throughout the SIS scaffold. The regenerated tissue was well organized and showed good integration with the adjacent fascia while the control specimens were filled with loose areolar connective tissue. At 12 weeks the experimental defects were filled with a regenerated tissue that grossly and histologically resembled normal fascia. There was no evidence of adhesions to the underlying musculature. Conversely, the tissue that filled the control defects remained disorganized and was markedly thinner than the adjacent fascia. The results of this study suggest that SIS is capable of supporting tissue regeneration in large fascial defects. The ability of this material to induce regeneration of a substantial area of tissue grossly and histologically similar to normal fascia and without adhesions to the underlying musculature makes its application in reconstructive surgery appear promising.

The sensory tensor fasciae latae flap: a 9-year follow-up.

From January 1979 to April 1989, 19 neurosensory tensor fasciae latae flaps were used to cover ischial pressure sores in paraplegic patients. This flap provides protective sensation and improves the sensory control of the filling status of the rectum and the sitting control in a wheelchair. Patients were reexamined between 12 and 110 months; no recurrence or new pressure sores were seen. Indications, early and late complications, and evolution of the sensation are discussed.

Functional differentiation within the tensor fasciae latae. A telemetered electromyographic analysis of its locomotor roles.

Electromyograms recorded by three or four fine-wire bipolar electrodes inserted along a transverse line across the right tensor fasciae latae of ten normal adults (five men and five women, twenty to thirty-six years old) during a standardized series of exercises and locomotor activities demonstrated different functional roles for the anteromedial and posterolateral fibers of the muscle. Although anatomical dissections in six normal cadavera demonstrated that the force of contraction of the tensor fasciae latae could be transmitted to the knee by the iliotibial tract, the observed activity of this muscle can be explained completely in terms of its action at the hip. The anteromedial fibers have a greater mechanical advantage for hip flexion than do the posterolateral fibers, whereas the posterolateral fibers possess a better mechanical advantage for hip abduction and internal rotation. During walking the anteromedial fibers were electromyographically silent, whereas the posterolateral fibers were active near heel-strike. For all subjects, increased locomotor velocity (during jogging, running, and sprinting) was associated both with increased activity of the anteromedial fibers near toe-off apparently to assist deceleration of extension and acceleration of flexion of the thigh, and with increased activity of the posterolateral fibers at heel-strike.