Effects of a tensioned tendon graft in a bone tunnel across the rabbit physis

Children who sustain anterior cruciate disruption often are denied the standard reconstructive procedures because of the concern that drilling across the physis of the tibia and femur and compression from a tensioned graft will result in growth plate arrest. To test this concept and to assess whether a tendon placed in the tunnel would function in a manner similar to a fat graft after the resection of a physeal bar, tunnels were made across the proximal tibial physis and distal femoral physis in a group of immature rabbits. Four tunnel diameters were used from 1.95 to 3.97 mm, in three rabbits at each diameter, with patellar tendon autografts being used as the reconstruction of the anterior cruciate ligament in two of the animals. The knees were radiographed every 4 weeks, and the animals were euthanized 4 months after surgery. The surgically treated and control knees were salvaged, and each knee was examined grossly, radiographically, and histologically. Eight of the 11 animals had growth arrest of one or both physes. The larger the drill hole diameter the more marked was the deformity. The proximal tibial physis seemed to be the most vulnerable for growth arrest, occurring in eight of the knees. The insertion of a tendon did not seem to offer any protection to physeal arrest. Because of these findings, it is not recommended that tunnels involving 1% or more of the area of the physis be placed across the tibial and femoral physis to reconstruct the anterior cruciate in very skeletally immature children.     

A histologic analysis of plantar fibromatosis.

Space occupying lesions of the plantar aspect can be a most preplexing surgical problem. Investigation into the histopathology of one of these lesions is presented. An in-depth cellular analysis of primary structures related to abnormal findings is also presented.     

一期植骨结合VSD治疗严重开放性Pilon骨折的疗效分析

目的 探讨一期植骨结合负压封闭引流术在治疗开放性复杂Pilon骨折中的临床疗效.方法 回顾性研究湖北医药学院附属东风总医院2010年1月-2012年1月收治的开放性复杂Pilon骨折56例,全部采用一期植骨结合负压封闭引流术,有限内固定结合外固定支架治疗,搜集术后皮瓣和软组织愈合情况、骨折愈合率、踝关节功能评分等临床资料.结果 骨折全部愈合,无创面软组织感染缺血等并发症发生.Helfer评分,优22例,良21例,可8例,差5例,优良率达到了76.8％.结论 一期植骨结合负压封闭引流术治疗严重开放性Pilon骨折可同时处理骨折复位固定、骨缺损及软组织覆盖等问题,具有操作简单、预防感染明显、骨折愈合率高和关节功能恢复良好等作用.     

Radioscapholunate ligament: a gross anatomic and histologic study of fetal and adult wrists

The radioscapholunate ligament was studied using fifty-four dissected adult cadaver wrists. Four of these wrists had arterial perfusions with colored latex and serial sections were made of twenty-one wrists from fetuses ranging in size from 23 to 230 millimeters crown-rump length. The radioscapholunate ligament was consistently identified between the long and short radiolunate ligaments, emerging through the palmar capsule of the radiocarpal joint. It was found to be a neurovascular structure surrounded by synovial tissue with vascular origins from the anterior interosseous and radial arteries and a neural origin from the anterior interosseous nerve. On entering the radiocarpal joint it attaches proximally to the interfacet prominence on the articular surface of the radius and distally to form the proximal membrane of the scapholunate interosseous ligament system. We found no anatomic evidence that this structure should be considered a ligament in a traditional mechanical sense. However, this structure may be clinically important as the vascular supply of the scapholunate interosseous ligament, as well as a sensory pathway from the scapholunate articulation.     

A comparison of nerve regeneration across a sural nerve graft and a vascularized pseudosheath

Nerve regeneration across a vascularized pseudosheath and a sural nerve graft was compared in a primate model using histologic and electrophysiologic parameters for regeneration. At 12 months, regeneration was noted across both the vascularized pseudosheath and the sural nerve graft. Although histologic and electrophysiologic properties of the regenerated nerve were significantly different from the normal ulnar nerve, the quality of regeneration noted between experimental groups was similar.     

A local direct effect of pituitary graft on growth of the lateral prostate in rats.

Prolactin and testosterone are synergistic in stimulating growth of the rat prostate. The lateral lobe is more sensitive to this synergism than the ventral and dorsal lobes. To investigate whether prolactin acts directly in the rat prostate or indirectly through another systemic mediator, anterior pituitary grafts (1 mm3) were implanted in the lateral prostate of castrated Sprague-Dawley rats in whom a 0.5 cm or 1.0 cm testosterone-filled silastic tubing was implanted subcutaneously at the same time. Rats were randomly assigned to receive either the pituitary or a muscle chip of similar size grafted beneath the fascia lateral to the lateral prostate. Twenty-one days later, serum prolactin levels were not elevated in pituitary-grafted animals and were not significantly different from those in muscle-grafted rats. The mean lateral prostate weight on the grafted side in pituitary-implanted rats with 1.0 cm testosterone tubing was 43% heavier than either that of the contralateral side or the corresponding weights in muscle-implanted rats. In pituitary-implanted rats with 0.5 cm testosterone tubing, the mean lateral prostate weight on the grafted side was 60% heavier than either that of the contralateral side or that of the corresponding weights in muscle-implanted rats. The weight of the ventral and dorsal lobes of the prostate was not significantly affected by the presence of pituitary grafts in one of the lateral lobes. The local effect of prolactin on the lateral prostate was further demonstrated by an overall decline in tissue concentrations of dihydrotestosterone in the grafted side. These results provided evidence to indicate that there was a direct effect of prolactin on growth of the lateral prostate in rats.     

Pancreas transplantation: the histologic morphology of graft loss and clinical correlations.

BACKGROUND: Graft losses due to leaks, bleeding, thrombosis, infections, and early pancreatitis are grouped together under the category of technical failure. Among these complications, massive vascular thrombosis continues to be the most important cause of early graft loss due to technical failure. Pathological evaluation of most allografts lost early in the posttransplantation period shows vascular thrombosis with associated proportional parenchymal necrosis. The morphological findings in allografts that are considered to be lost due to technical failure has not been systematically addressed. In particular, the role of acute rejection in early graft loss has not been well studied. METHODS: Seventy-four consecutive pancreas graft pancreatectomies were studied histologically to evaluate for thrombosis (recent versus organized), type of vessel involved by thrombosis (arteries, veins, or both), acute rejection grade, chronic rejection grade, endotheliitis, transplant arteritis, coagulation necrosis, acute pancreatitis, presence of infectious organisms, transplant (obliterative) arteriopathy, neoplasia, relative proportions of alpha and beta islet cells, and immunoglobulin and complement deposition. The histological findings were correlated with donor and recipient data as well as clinical presentation. RESULTS: In 23 out of 39 grafts lost in the first 4 weeks posttransplantation, the only pathological changes found were vascular thrombosis and bland ischemic parenchymal necrosis. In these cases, no underlying vascular pathology or any other specific histological change was identified. Most of these grafts (78%) were lost in less than 48 hr and all in the first 2 weeks posttransplantation. Massive vascular thrombosis occurring in an otherwise histologically normal pancreas was the most common cause of graft loss in the first 4 weeks posttransplantation (59%). In most of the remaining cases (33%), although the clinical presentation suggested technical failure, there was clear histological evidence that the massive thrombosis resulted from vascular injury due to immune damage (acute and hyperacute rejection). Increased incidence of early graft thrombosis was seen in grafts from older donors and longer cold ischemia times. After the first month posttransplantation, graft pancreatectomies revealed a wider variety of pathological processes that included severe acute rejection, combined acute and chronic rejection, chronic rejection, and infections. Acute and chronic vascular thrombosis in large and small vessels was commonly seen at all times posttransplantation; chronic, organized thrombosis was strongly associated with chronic rejection. CONCLUSIONS: (a) Early acute thrombosis occurring in a histologically normal pancreas defines a true technical failure. This study showed that acute rejection leading to massive thrombosis, which clinically simulates technical failure, results in a significant proportion of early graft losses. (b) Systematic histological evaluation of failed grafts is absolutely necessary for the accurate classification of the cause of graft loss. (c) There is morphological evidence that chronically ongoing thrombosis is an important, common, contributing factor for late graft loss.     

The bladder acellular matrix graft in a rat chemical cystitis model: functional and histologic evaluation

PURPOSE: We investigated the feasibility of augmentation in a diseased bladder with a bladder acellular matrix graft. MATERIALS AND METHODS: In 50 female Sprague-Dawley rats chemical cystitis was induced by intravesical instillation of HCl repeated monthly to maintain chronic inflammation. Urodynamic studies were performed in all rats 1 week after the induction of chemical cystitis and repeated at sacrifice. The 29 rats in the experimental group underwent partial cystectomy (50% or greater), followed by bladder acellular matrix graft augmentation, while the 21 controls underwent monthly HCl instillation only. The rats were sacrificed at 2 weeks, 1, 2 and 3 months, respectively. The bladder was removed and examined for histological changes. RESULTS: Urodynamic studies showed that bladder capacity and compliance were significantly higher in the grafted than in the control group (p = 0.008 and 0.006, respectively, at 3 months). Histological studies revealed urothelial and smooth muscle regeneration within the bladder acellular matrix graft at 1 month and nerve regeneration at 3. The number of mast cells was significantly lower in the grafted region than in the host bladder of all grafted rats (p <0.001). CONCLUSIONS: In this rat chemical cystitis model bladder augmentation with a bladder acellular matrix graft led to functional and histological improvement over diseased host bladder.     

The effect of locally applied vascular endothelial growth factor on meniscus healing: gross and histological findings

Introduction: Tears in the peripheral part of the menisci have a better healing potential than tears in the central part, because the central two-thirds of the menisci are avascular. We hypothesized that healing of meniscus tears in the avascular zone can be promoted by the local application of the angiogenic factor vascular endothelial growth factor (VEGF). Materials and methods: A tear was created in the avascular zone of the medial meniscus in 18 merino sheep. The tear was then repaired with an uncoated suture (group 1), a suture coated with PDLLA (group 2), and by a suture coated with PDLLA/VEGF (group 3). Results: After 6 weeks, we observed increased immunostaining for factor VIII in the VEGF-treated group 3. However, in this treatment group no meniscus healed completely. In the uncoated suture group and in the PDLLA-coated-suture group, partial healing was observed in three animals and complete healing in three animals, respectively. Conclusion: In this experiment the local application of VEGF via PDLLA-coated sutures did not promote meniscus healing. Growth factors might not always be a promising tool for tissue repair.     

Recurrent malignant fibrous histiocytoma. A histologic analysis of 50 cases

This clinicopathologic study deals with 84 patients who had recurrent malignant fibrous histiocytoma (MFH), and is primarily concerned with 50 cases in which specimens of both the initial and recurrent tumors were available for histopathologic examination. Quantitative and qualitative differences in the histologic patterns characterizing MFH, such as storiform and myxoid, between the initial and recurrent tumors, were clear-cut in nearly two-thirds of the cases. Conversion in histologic subtypes of MFH occurred in nine cases, including six cases which converted from myxoid to nonmyxoid pleomorphic. The superficially located tumors recurred somewhat more frequently, but in such cases, there was a significantly better prognosis than was seen with the deeply located tumors. Changes in the degree of mitotic rate, nuclear atypism, and cellularity from the initial to the recurrent tumor correlated better with the biological behavior of the tumor than did the degree in the initial tumor itself. The increased proportion of histiocyte-like tumor cells in the recurrent tumor was another morpholic feature which indicated a much poorer prognosis than did the increased proportion of fibroblast-like tumor cells.     

表皮生长因子对大鼠移植小肠形态及功能的作用研究

目的：了解表皮生长因子（epidermal growth factor，EGF）对大鼠移植小肠萎缩及功能低下的预防作用。方法：近交系Wistar(RT1^k)大鼠行异位全小肠移植后自第2天开始给予肠外营养至第10天，对照组（n=10）行常规TPN(total parenteral nutrition)支持，实验组（n=10）行常规TPN支持的同时加用表皮生长因子。结果：实验组移植肠绒毛高度、隐窝深度、粘膜厚度及绒毛表面积均明显大于对照组，肠上皮细胞超微结构基因保持完好，对照组则出现明显线粒体肿胀和微绒毛萎缩。实验组血浆^15N-甘氨酸丰度明显于对照组。结论：表皮生长因子能维护大鼠移植小肠粘膜形态与功能，改善肠管对氨基酸的吸收。     

The effect of fibrin glue on fat graft survival.

Autologous fat transplantation for filling defects or augmenting tissue is a common procedure but may have unreliable results. While fibrin glues lead to increased proliferation of fibroblasts and local accumulation of vascular endothelial growth factor, which enhances the neovascularisation, in this study the efficacy of fibrin glues on fat graft survival was investigated. Inguinal fat pads from Sprague-Dawley rats were harvested and same volumes of autogenous fat grafts were implanted into the separate pockets with the aid of fibrin glue (Group 1) and saline solution (Group 2). All the fat grafts were harvested, washed, blotted dry, and volumetrically measured with the same method used peroperatively at 6 months after implantation. Mean graft survival values for Group 1 were compared with Group 2 and histopathological evaluation of the grafts was also made. There was a significantly higher survival rate of the grafts in Group 1 than control group (79+/-4% and 55+/-6%, respectively). Histopathological examination of the grafts demonstrated evident increase in neovascularisation of the fat grafts in the experimental group. The authors conclude that the fibrin glue significantly diminishes the fat graft resorption and further well-controlled studies are required before using fibrin glues for clinical purposes.