Evidence Of Resorption Research Articles

A Histological and Clinical Study of MatriDerm® Use in Burn Reconstruction.

Dermal substitutes are well established in the reconstructive ladder. MatriDerm® (Dr. Otto Suwelack Skin & Health Care AG, Billerbeck, Germany) is a single-layer dermal substitute composed of a bovine collagen (type I, III, and V) and elastin hydrolysate, that allows for immediate split-thickness skin grafting (SSG). The aim of this study was to histologically characterize the integration of MatriDerm® when used during burns surgery reconstruction. Eight subjects with nine burn scars and one acute burn wound underwent reconstruction with MatriDerm® and an immediate SSG. MatriDerm® integration and skin graft take were assessed with serial biopsies performed at weeks 1, 2, 3, and 4 and months 2, 3, 6, 9, and 12. Biopsies were assessed with standard special stains and immunohistochemistry, and representative slides were imaged with a transmission electron microscope. Patient satisfaction and clinical scar outcome were assessed with the Vancouver Scar Scale and a patient questionnaire. Histological analysis showed similar stages of wound healing as shown in other dermal templates but on a different timescale. There is early evidence of vascularization and an inflammatory infiltrate in the first 2 weeks. MatriDerm® is resorbed earlier than other dermal substitutes, with evidence of resorption at week 3, to be completely replaced by a neodermis at 2 months. The use of MatriDerm® in reconstruction with immediate skin grafting is supported histologically with early evidence of vascularization to support an epidermal autograft. Future histological studies may help further characterize the ideal dermal substitute.

Medialisation laryngoplasty with bone wax in a sheep model.

To evaluate the safety and biocompatibility of bone wax as an implant material for medialisation laryngoplasty in a large animal model. Three Dorper-cross ewes underwent type I thyroplasty of the right vocal fold with bone wax. The animals were monitored for four weeks for general wellbeing. The animals were euthanised and the larynges harvested. Histological evaluation was performed to assess for adverse tissue reaction and biocompatibility. The mean (± standard deviation) amount of bone wax implanted was 0.49 g (± 0.12 g). No adverse events were reported. Ex vivo vibration was present on high-speed imaging for all medialised vocal folds. Histology demonstrated implanted paraffin embedded within the thyroarytenoid muscle with no evidence of resorption, a minimal inflammatory infiltrate, and a thin fibrotic capsule. The results of this investigation suggest that bone wax may be a safe and efficacious implant material for medialisation laryngoplasty. Further studies are necessary to assess its long-term safety and efficacy.

The function of the calcium channel Orai1 in osteoclast development.

To determine the intrinsic role of Orai1 in osteoclast development, Orai1-floxed mice were bred with LysMcre mice to delete Orai1 from the myeloid lineage. PCR, in situ labelling and Western analysis showed Orai1 deletion in myeloid-lineage cells, including osteoclasts, as expected. Surprisingly, bone resorption was maintained in vivo, despite loss of multinucleated osteoclasts; instead, a large number of mononuclear cells bearing tartrate resistant acid phosphatase were observed on cell surfaces. An in vitro resorption assay confirmed that RANKL-treated Orai1 null cells, also TRAP-positive but mononuclear, degraded matrix, albeit at a reduced rate compared to wild type osteoclasts. This shows that mononuclear osteoclasts can degrade bone, albeit less efficiently. Further unexpected findings included that Orai1fl/fl -LysMcre vertebrae showed slightly reduced bone density in 16-week-old mice, despite Orai1 deletion only in myeloid cells; however, this mild difference resolved with age. In summary, in vitro analysis showed a severe defect in osteoclast multinucleation in Orai1 negative mononuclear cells, consistent with prior studies using less targeted strategies, but with evidence of resorption in vivo and unexpected secondary effects on bone formation leaving bone mass largely unaffected.

Histological analysis of failed submucosa patches in congenital cardiac surgery.

Objective Porcine small intestinal submucosa extracellular matrix is a biological substitute used in cardiovascular surgery to correct congenital heart defects. Previous studies with this material have shown satisfactory results. In contrast, there are singular reports of patch-associated complications with CorMatrix small intestinal submucosa extracellular matrix. We report the histopathological findings of explanted extracellular matrix patches that were removed because of early failure in patients with congenital heart defects. Methods Explanted patch materials from 4 patients (aged 9 months to 41 years), who underwent reoperation due to early patch failure, were analyzed. Initial surgery comprised one aortic valve reconstruction, one pulmonary valve reconstruction, one atrioventricular septal defect repair, and one aortic arch enlargement. The interval between operations ranged from 69 to 553 days. Results Residual extracellular matrix patch material was evident at explantation in all cases and presented as a structured eosinophilic and anucleate specimen. In two cases, a local focus of scarring and pseudocartilaginous transformation with evidence of calcification was found. There was no evidence of absorption of patch material in any case, nor repopulation by organized tissue formation. Conclusions Histologic examination of explanted extracellular matrix patches showed no evidence of resorption or relevant repopulation with resident cells nor formation of functional tissue structures. In contrast, a mixed chronic inflammatory infiltration, early signs of calcification, and scarring as well as focal pseudocartilaginous transformation were found. Considering recent reports, close follow-up of patients with extracellular matrix patches is recommended to evaluate the performance of this novel material and detect potential problems.

MAXILLARY CANINE FOLLICULAR SPACE AND LATERAL INCISOR ROOT RESORPTION: A CBCT STUDY

Background It has been shown that the dental follicle is necessary for signaling osteoclasts to induce resorption of bone in the direction of the eruption.1 A dental follicle can also induce resorption of nearby anatomic structures, including adjacent teeth, if there is insufficient space for the tooth to emerge. Objective The objective of this study was to identify patterns of resorption in maxillary lateral incisor roots and investigate a relationship to the width of the follicular space of the adjacent erupting canines. Methods Three hundred and thirty cone beam computed tomography (CBCT) volumes were obtained from an orthodontic practice, and identifying data were removed according to institutional review board guidelines. Each volume was analyzed for the presence of unerupted canines and lateral incisor. Results From the sagittal, the range of follicle sizes was 0.5 to 4.9 mm. From the axial, the range of follicle sizes was 0.5 to 4.9 mm. From the coronal, the range of follicle sizes was 0.5 to 5.4 mm. At a cutoff point of 2.03 mm, there was 76%, and sensitivity was 72%. Discussion The study included 252 canine teeth with enlarged follicular spaces. Fifty-two lateral incisors showed radiographic evidence of resorption, almost always on the distal–palatal aspect of the root. The statistical model predicted that if the follicle has an average size of 2.03 mm or greater, the patient has a higher predisposition of having lateral incisor root resorption on the same side.

Total hip arthroplasty with structural bone graft of superolateral acetabulum for developmental dysplasia of the hip

Objective To assess the mid- or long-term clinical outcomes of the structural bone graft of superolateral acetabulum in total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH). Methods Thirty-three patients with DDH (33 hips) were treated by THA with the structural bone graft of superolateral acetabulum technique between April 2002 and December 2011. There were 28 females and 5 males with the mean age at surgery 54.0±14.5 years (21-76 years). The degree of dislocation was graded preoperatively as Crowe II in 12 patients, Crowe III in 8 patients, and Crowe IV in 13 patients. The following outcomes were assessed, Harris hip score (HHS), the leg-length discrepancy, the height and horizontal distance of center of hip rotation, rate of cup coverage, the coverage ratio of bone graft, periprosthetic osteolysis, bone ingrowth, and cup loosening. Results The average follow-up was 9.3±3.3 years (5-15 years). The HHS improved from 40.9±13.7 preoperatively to 93.6±7.8 at the final follow-up (t=21.483, P=0.000). The leg-length discrepancy decreased from 24.2±17.1 mm pre-operatively to 3.7±3.5 mm at post-operative 3 months (t=6.747, P=0.000). The height and horizontal distance of center of hip rotation decreased from preoperative 45.9±16.0 mm and 42.9±8.7 mm to postoperative 23.8±5.8 mm and 23.6±2.9 mm (t=7.460, P=0.000; t=12.090, P=0.000) at post-operative 3 days, respectively. The cup coverage and coverage ratio of bone graft was 100% and 27.1%±6.9%, respectively. All grafts appeared to be incorporated without evidence of resorption and collapse. The mean time of incorporation was 7.6±2.8 months. The coverage ratio of bone graft >25% have a significantly long time of incorporation than that <25% (9.4±2.3 months versus 6.3±2.4 months, t=5.357, P=0.000). At the final follow-up, all hips showed bone ingrowth fixation of the acetabular cup and stem. Five hips showed osteolysis, two hips in acetabular zone II, three hips in femur zone I and five hips in femur zone VII. The main complications were intraoperative femoral fractures (61%) without neurological damage, nonunion and dislocation. Conclusion The structural bone graft of superolateral acetabulum in THA for DDH can achieve satisfactory mid- or long-term outcomes. The superolateral acetabular deficiency can be reconstructed by bone graft. The bone graft coverage less than 25% is conducive to fusion of bone graft and acetabular bone. However, intraoperative femoral fracture is common complication. Key words: Bone diseases, developmental; Bone transplantation; Arthroplasty, replacement, hip

Asymptomatic calcifying cystic odontogenic tumor presenting as a random radiographic finding

Calcifying cystic odontogenic tumor (CCOT), a rare odontogenic lesion, usually appears as radiolucency with radiopacities. This characteristic finding may not always be evident depending on the lesion stage, growth, and histopathological features. An asymptomatic case of CCOT alongside an unerupted third molar that was discovered randomly after a routine panoramic radiograph is presented in a 28-year-old male patient. The imaging examination by cone beam computed tomography revealed a unilocular corticated radiolucency in close association with the buccal aspect of a fully impacted mandibular third molar that extended to the apical third of the tooth. The roots appeared outside the lesion and there was no evidence of resorption or jaw bone erosion. Based on the imaging findings, the provisional clinical diagnosis was dentigerous cyst. After the surgical removal of the cystic lesion, which had adhered in the cemento-enamel junction of the third molar, the histopathological examination showed a CCOT. Unerupted third molars should be investigated radiographically even in the absence of clinical signs for the early diagnosis and management of the various odontogenic cysts and tumors.

Trasplante con aloinjerto estructural de astrágalo en lesión osteocondral masiva

Large osteochondral defects of the talus present a difficult clinical problem to orthopaedic surgeons. Massive-volume deep cystic lesions are rare. The use of an allograft transplantation offers an alternative in the treatment of these extensive lesions involving the talar dome.We report on the outcome after an osteochondral fresh frozen allograft transplantation in a case of a 53-year old-woman with a massive cystic lesion of the talus.No evidence of resorption or failure of the graft has been observed after 1 year of follow up. Radiological examination shows signs of union and incoroporation of the graft without subchondral collapse or fragmentation. After 1 year se has no pain and she is able to walk independently without assistance.The present case offers a surgical alternative for massive lesions of the talus, that use rigidly fixed ostechondal allograft transplantation. Mid and long term survival of these kind of allografts remains unknown. Despite the good results after one year, worse outcomes or failures can be expected in the future.

Structural &amp; functional rehabilitation in eyes with lamina resorption following MOOKP—can the lamina be salvaged?

To describe a new technique and analyze the outcome of procedures performed for anatomic and functional rehabilitation in eyes with lamina resorption following the modified osteo-odonto keratoprosthesis (MOOKP) procedure. Retrospective case series. Eighteen eyes were noted to have lamina resorption of the 85 eyes that underwent the MOOKP surgery over the last 10 years. Further intervention to salvage the globe, and therefore the visual potential, was possible in only 11 eyes, of which two are yet to undergo further intervention. Two patients who had undergone the procedure elsewhere also presented to our centre with evidence of resorption. In all, 11 eyes (nine operated at our centre, two operated elsewhere) were included in this study. Bone morphogenetic protein (BMP) was used alone or along with mandibular cancellous bone within the fibrovascular capsule of the osteo-odonto alveolar lamina, in an effort to prevent further resorption and promote bone generation in areas of resorption in ten eyes. In three of these eyes, there was a continued progression of resorption requiring lamina removal. In these three eyes and another eye with extrusion of the cylinder from the eye, the Lucia Type 2 keratoprosthesis was performed for visual rehabilitation (four eyes). The BMP procedure was performed in ten eyes. Continued resorption with need for further rehabilitative surgery in the form of Lucia Type 2 Kpro was required in three of these eyes. Of the four patients who had the Lucia Type 2 Kpro, visual acuity improved to better than 20/200 in three eyes over a mean follow-up period of 3 months. Of the remaining seven eyes that had the BMP procedure performed, all have remained stable with respect to anatomic integrity of the lamina and globe, with maintenance of or improvement in pre BMP visual acuity over a mean follow-up of 9.2 months. No other complications of the procedure were noted. Resorption of the lamina in MOOKP can be addressed by reinforcing the same with BMP in eyes where the cylinder mobility is not significant, as a means to prolong the longevity of the existing lamina. The Lucia Type 2 Kpro might also have a role to play in the functional rehabilitation of eyes with severe lamina resorption or cylinder extrusion if preparation of a new lamina cannot be performed for various reasons.

Use of Immediate Dermal Fat Graft for Scalp Contour Defect Following Resection of Arteriovenous Malformation

Arterial venous malformations (AVMs) are rare conditions that are difficult to manage. Therapeutic options include selective embolization with or without surgical excision. Recurrence, however, is high despite correction of the primary abnormality. Cosmetic concern is among the indications for treatment, particularly if the AVM occurs on the face or scalp. Historically, AVM excision and the residual defect correction have been performed separately. We present the first case reported of a successful embolization and interval excision with immediate reconstruction using a dermal fat graft, as a novel approach to correct soft tissue defect following the resection of an AVM. A 35-year-old man presented with a 20-year history of a nonpulsating mass posterior to the hairline in the right frontoparietal region, measuring 4.0 cm on its longest axis. Embolization of the AVM was achieved by injecting N-butyl cyanoacrylic acid and ethiodol. One month after embolization, surgical excision of the mass was performed. The resulting disfiguring contour defect was immediately corrected using a dermal fat graft harvested from the groin. At 4 months' follow-up, the graft was viable with no evidence of resorption or epidermal cyst formation. In addition, there was no recurrence of the AVM and no complications at the donor site. This case demonstrates the utility of a dermal fat grafts in correcting the impending defect in 1 stage avoiding a second-stage procedure and significant period of cosmetic disfigurement. This method should be considered as a treatment option for patients requiring moderately sized AVM excisions in cosmetically sensitive areas.

Intracoronary Optical Coherence Tomography and Histology at 1 Month and 2, 3, and 4 Years After Implantation of Everolimus-Eluting Bioresorbable Vascular Scaffolds in a Porcine Coronary Artery Model

Background— With the use of optical coherence tomography (OCT), alterations of the reflectance characteristics of everolimus-eluting bioresorbable vascular scaffold (BVS) struts have been reported in humans. In the absence of histology, the interpretation of the appearances of the struts by OCT remains speculative. We therefore report OCT findings with corresponding histology in the porcine coronary artery model immediately after and at 28 days and 2, 3, and 4 years after BVS implantation. Methods and Results— Thirty-five polymeric BVS (3.0×12.0 mm) were singly implanted in the main coronary arteries of 17 pigs that underwent OCT and were then euthanized immediately (n=2), at 28 days (n=2), at 2 years (n=3), at 3 years (n=5), or at 4 years (n=5) after implantation. All BVS-implanted arteries in these animals were evaluated by histology except for 5 arteries examined at 2 years with gel permeation chromatography to assess the biodegradation of the polymeric device. Fourteen arteries with BVS from an additional 6 pigs were examined by gel permeation chromatography at 1 (n=1), 1.5 (n=2), and 3 (n=2) years. Corresponding OCT and histology images were selected with the distal and proximal radiopaque markers used as landmarks. At 28 days, by OCT, 82% of struts showed sharply defined, bright reflection borders, best described as a box-shaped appearance. Histologically, all struts appeared intact with no evidence of resorption. At 2 years, by OCT, 60±20 struts were discernible per BVS with 80.4% of the strut sites as a box-shaped appearance. Despite their defined appearance by OCT, by histology, these structures appeared to be composed of proteoglycan, with polymeric material being at such low level as to be no longer quantifiable by chromatography. At 3 years, by OCT, recognizable struts decreased to 28±9 struts per BVS: 43.7% showed dissolved black box; 34.8%, dissolved bright box; 16.1%, open box; and 5.4%, preserved box appearance. Histology shows that connective tissue cells within a proteoglycan-rich matrix replaced the areas previously occupied by the polymeric struts and coalesced into the arterial wall. At 4 years, by OCT, 10±6 struts were recognizable as either dissolved black or dissolved bright box. In histology, these struts are minimally discernible as foci of low-cellular-density connective tissue. Relative to the prediction of histological type by OCT appearance, the preserved box appearance of OCT corresponds well with 2-year histology (86.4%), whereas the dissolved bright and black box appearances correspond to 3-year histology (88.0% and 90.7%, respectively). Struts indiscernible by OCT correspond to the integrated strut footprints seen at 4 years (100%). Conclusions— Struts that are still discernible by OCT at 2 years are compatible with largely bioresorbed struts, as demonstrated by histological and gel permeation chromatography analysis. At 3 and 4 years, both OCT and histology confirm complete integration of the struts into the arterial wall.

Evaluation of the Long-Term Results of Rat Cranial Bone Repair Using a Particular Xenograft

Bone defects that cannot be healed completely are termed critical-sized defects and can be used to test bone grafts for medicine, dentistry, and periodontology. The aim of the present study was to detect the effects of a xenograft (Unilab Surgibone) on bone building in experimentally created parietal bone defects in rats. Standardized parietal bone defects were created in 16 rats, and each defect had a circular morphology 6 mm in diameter. The right defect sites were filled with porous particle material, and the left site was used as control. After the 3rd, 6th, and 12th months, rats were killed and tissue samples obtained from the related site of the cranium. Subsequently, histological sections were taken and stained with different stains for evaluation under light microscope. The rate of bone formation was assessed using a semiquantitative method. These results showed that dense collagenous tissue was observed in the control area during the third month, whereas xenograft particles were surrounded by a fibrous tissue layer at the implantation site. Osteoclast-like cells were also observed. There was also no significant bone repair at other observation periods. It can be concluded that the material used had no evidence of resorption and does not enhance bone formation. However, it seems biocompatible, osteoconductive, and could be used in a limited manner as a material for filling osseous defects in clinical practice.

Root Shortening in Patients Treated with Two-step and En Masse Space Closure Procedures with Sliding Mechanics

To investigate the comparative amount of root shortening between two-step and en masse space closure procedures. Fifty-two patients were selected from a pool of patients satisfying the following inclusion criteria: no evidence of resorption on the pretreatment panoramic radiographs; no dental trauma; no dilacerations of incisor roots, anodontia, or impacted canines; complete root formation at the start of treatment; intact and caries-free incisors; no endodontically treated incisors; Angle Class I or II malocclusion; extraction of four first premolars; and space closure with moderate anchorage. Patients received treatment with either a two-step or an en masse procedure to close the extraction spaces after alignment and leveling with the same preadjusted appliances. Root shortening of the maxillary and mandibular incisors was evaluated on panoramic radiographs, taken before and after space closure, and measured in millimeters. Distortion of measurements caused by panoramic radiographs was corrected by using special metal rods ligated to brackets. Statistical comparisons of root shortening between space closure procedures were investigated with the two-sample t test. No difference was found in the amount of root shortening between space closure procedures. The average root shortening of maxillary central and lateral incisors was 0.43 +/- 0.12 mm and 0.58 +/- 0.10 mm, respectively, and that of mandibular central and lateral incisors was 0.23 +/- 0.07 mm and 0.22 +/- 0.06 mm, respectively. No difference should be expected in root resorption between two-step and en masse space closure procedure.

External apical root resorption in patients treated with conventional and self-ligating brackets

Our aim was to comparatively investigate the amount of external apical root resorption (EARR) between conventional and passive self-ligating brackets. Ninety-six patients were selected from a pool of patients satisfying the following inclusion criteria: no evidence of resorption on the pretreatment panoramic radiographs; no contributing history of trauma; no dilacerations of lateral incisor roots, maxillary anodontia, and impacted canines; complete root formation at the start of treatment; intact and caries-free maxillary incisors; and no endodontically treated incisors. Patients received treatment with either a passive self-ligating bracket system or a conventional edgewise appliance, both with a 0.022-in slot. EARR of the maxillary incisors was evaluated on panoramic radiographs, taken before and after orthodontic treatment measured in millimeters. Distortion of measurements caused by panoramic radiographs was investigated by using a calibrated periodontal probe attached to the lateral incisor, and the extent of magnification was estimated to be 14%. Statistical comparisons of EARR between appliance type, age, sex, extraction treatment, and duration of treatment were investigated with univariate and multivariate regression modeling. Overall, no difference was found in the amount of EARR between appliance systems. Age, sex, and extraction treatment were not reliable predictors of EARR, but a positive association between EARR and duration of treatment was observed. No difference should be expected for root resorption between conventional and passive self-ligating brackets.

Conductive deafness with normal eardrum: absence of the long process of the incus

Conclusions. The most likely cause of lesions with an absence of the long process of the incus was congenital origin because many cases were associated with the stapedial anomaly. However, the possibility of a potential inflammation of this lesion could not be completely excluded, especially in cases with only an absence of the long process of the incus. Objective. To clarify whether the absence of the long process of the incus is caused by congenital anomaly or a potential inflammation. Subjects and methods. A total of 21 patients (5 bilateral cases, 16 unilateral cases) with absence of the long process of the incus were reviewed. Operative and histopathological findings of the removed incus were analyzed. Results. The 21 cases with absence of the long process of the incus were classified into 6 types. Thirteen cases showed the absence of the long process associated with the stapedial anomaly, which were all unilateral. Eight cases showed no association with the stapedial anomaly, among which five cases were bilateral. Three of eight cases not associated with the stapedial anomaly showed evidence of resorption in the incus body such as fibrosis and Haversian canal widening.

Cavitary acetabular defects treated with morselized cancellous bone graft and cementless cups

The use of impacted morselized cancellous bone grafts in conjunction with cementless hemispherical acetabular cups for treatment of AAOS type II acetabular cavitary deficiencies was evaluated in a retrospective study of 23 primary and 24 revision total hip arthroplasties, at a mean follow-up of 7.9 and 8.1 years, respectively. All primary hips received autografts, while all revision hips received allografts. Modified Harris Hip Scores for primary and revision hip replacements increased from a pre-operative mean of 37 and 47 to a postoperative mean of 90 and 86, respectively. All 23 autografts and 23 out of 24 cancellous allografts were radiographically incorporated without evidence of resorption. There were no instances of infection, component migration, or cases requiring subsequent acetabular revision. We conclude that impacted morselized cancellous bone-graft augmentation of cementless cups is a viable surgical option for AAOS type II cavitary acetabular defects.

THE SILVER BOW SAPPHIRE OCCURRENCE, MONTANA: EVIDENCE FOR A VOLCANIC BEDROCK SOURCE FOR MONTANA'S ALLUVIAL SAPPHIRE DEPOSITS

The first confirmed bedrock source of alluvial sapphire deposits in southwest Montana has been found 9 km west of Butte, Montana. The source rock of the Silver Bow occurrence is a sapphire-bearing felsic lapilli tuff of the Eocene Lowland Creek volcanic field. Such a felsic composition is atypical of known primary sapphire deposits and may represent a previously unrecognized deposit type. Mass wasting of this volcanic unit during the Quaternary resulted in the deposition of several debris flow deposits, which constitute the majority of the sapphire deposit. Two distinct populations of sapphires were recovered from the debris flow deposits: over 5,500 pastel sapphires and 54 dark blue sapphires. The pastel sapphires exhibit surfaces indicative of resorption and in some cases spinel reaction rims. Xenoliths of amphibolite facies corundum-bearing biotite-sillimanite schist, as well as grains of garnet and spinel were also recovered from the debris-flow deposits. Based on these observations, the pastel sapphires are interpreted to be refractory xenocrysts of metamorphic origin. The second population of dark blue sapphires show little if any evidence of resorption and have no adhering reaction minerals. Due to these differences, we postulate that the dark blue sapphires are magmatic phenocrysts, the source melt for which is represented by a fragment of igneous rock recovered from the debris-flow deposits containing phenocrysts of dark blue sapphire.

Magnetic Resonance Imaging Evaluation of Biodegradable Transfemoral Fixation Used in Anterior Cruciate Ligament Reconstruction

The study was designed to evaluate bioabsorbable transfemoral fixation in anterior cruciate ligament (ACL) reconstruction using hamstring tendon as graft. Magnetic resonance imaging (MRI) was used to assess the continuity of the bioabsorbable implant at different stages of the patients' rehabilitation. Retrospective case series. Forty-nine patients underwent ACL reconstruction performed by a single surgeon. The graft, a tensioned quadrupled semitendinosus tendon, was fixed proximally using a bioabsorbable TransFix implant (Arthrex, Naples, FL). The patients underwent an accelerated rehabilitation program and were assessed clinically at regular intervals postoperatively using MRI, with specific attention focused on the implant. The average time from surgery to MRI was 28 weeks (range, 4 to 54 weeks). All implants were fully visible with no evidence of resorption. Five implants were fractured at an average of 20 weeks postoperatively (range, 9 to 47 weeks). Three implants showed deformation but no definite fracture at an average of 14 weeks (range, 12 to 17 weeks). This amounts to 16% of implants with fractures or deformation, many close to the period of theoretical graft incorporation. All patients were clinically stable with no symptoms or signs or instability on clinical review and all had returned to preinjury sporting activities. Transfemoral biodegradable implants have the potential to fracture or deform during their postoperative course in tensioned hamstring tendon ACL reconstruction. Although no apparent detrimental effect was found in our series, further research is needed on this device before it can be recommended for ACL reconstruction. We also question the idea that rigid fixation for the ACL graft for the entire healing process is required. Level IV, retrospective case series.

Histopathological changes in the human larynx following expanded polytetrafluroethylene (Gore-Tex®) implantation

BackgroundExpanded polytetrafluroethelyne (e PTFE, Gore-Tex®) has been advocated as an implant material for medialization of the vocal fold. Animal studies involving rabbits and a porcine model have demonstrated host tolerance of the implant. There have been no reports describing the histological changes in a human laryngectomy specimen with a Gore-Tex implant.Case presentationThe histological findings in a laryngectomy specimen of a patient previously implanted with e PTFE for medialization of a paralyzed vocal fold following excision of a vagal neurofibroma were studied.Histopathology revealed a mild foreign-body giant cell granulomatous reaction with some associated fibrosis. The granulomatous response was limited to the periphery of the Gore-Tex and although it closely followed the profile of the material it did not encroach into or significantly break up the material. There was no significant neutrophilic or lymphocytic inflammation.ConclusionsOur findings are consistent with the animal models confirming that Gore-Tex implantation does not result in a significant granulomatous reaction in the human larynx over a 13-month period. Moreover, there is no evidence of resorption or infection. Further, the lack of lymphocytes in association with the granulomas indicates that there is no significant immunological hypersensitivity. Histologically, the slight permeation by connective tissue is similar to that seen in Gore-Tex vascular and cardiac implants. The degree of the slight giant cell response appears to be dependent on the profile of the material; a sharp edge incited more of a response than a flat surface.

Transcutaneous migration of a tibial bioabsorbable interference screw after anterior cruciate ligament reconstruction

We present a case of a poly-L-lactic acid (PLLA) tibial bioabsorbable interference screw disengaging and migrating transcutaneously 12 months after successful anterior cruciate ligament reconstruction with quadrupled hamstrings autograft. No graft insufficiency or joint inflammatory reaction was present. The screw was removed surgically with no evidence of resorption. The graft was well incorporated into the tibial tunnel. The patient recovered without difficulties and returned to her preinjury level of activity. To our knowledge, this is the first case reported of disengagement and extrusion of a PLLA bioabsorbable interference screw.