Posterior Graft Research Articles

Effect of exogenous recombined human bone morphogenetic protein-2 on cell proliferation in lumbar spinal fusion in a rabbit model

Objective To explore the effects of exogenous recombined human bone morphogenetic protein-2(rhBMP-2)on cell proliferation in posterolateral lumbar spinal fusion in a rabbit model. Methods Forty-five rabbits that had received posterior graft fusion of transverse process of lumbar vertebra were randomly divided into 3 groups: rhBMP-2/allograft composite group, autologous iliac crest bone graft group, and allograft group. The proliferations of marrow stromal cells (MSCs), osteoblasts and vascular endothelial cells were detected at different times by flow cytometry. Results The numbers of MSCs in the rhBMP-2/allograft composite group at the 2nd, 7th, 35th days after graft transplantation were significantly greater than in the autologous iliac crest bone graft group and allograft group (P 0.05) except at the 2nd day (P=0.028). The quantity of osteoblasts in composite group was significantly larger than in the allograft group at all time points (P<0.05) . The quantities of vascular endothelial cells in the composite group at the 2nd, 7th, 28th days after operation were significantly larger than in the autologous iliac crest bonegraft group (P<0.05). Conclusion The exogenous rhBMP-2 may have a promoting effect on proliferation of MSCs, osteoblasts, vascular endothelial cells at different times during the spinal graft fusion. Key words: Bone morphogcnetic protein; Spinal fusion; Bone transplantation; Cell proliferation

Arytenoid prolapse: A source of obstruction following laryngotracheoplasty

Objective Arytenoid prolapse is a potential source of upper airway obstruction following laryngotracheoplasty, and may be difficult to identify. We explored the incidence, clinical features, etiology, and surgical approach to patients with arytenoid prolapse following laryngotracheoplasty. Study Design Case series with chart review. Subjects and Methods The charts of 93 patients diagnosed with arytenoid prolapse following laryngotracheoplasty from 1981 to 2007 were reviewed. Results The incidence was 5.7 percent (93/1634). Forty-nine patients had unilateral prolapse; 44 had bilateral prolapse. Average time from laryngotracheoplasty to presentation was 36.8 months. Common symptoms were dyspnea on exertion, tracheostomy dependence, and sleep-disordered breathing. Fifty-four patients (58%) required surgical intervention, with arytenoid reduction performed in 45 patients. Nine underwent reduction during revision laryngotracheoplasty or cricotracheal resection. Fourteen patients required a second procedure for persistent prolapse. Thirty-nine (42%) required no intervention. Symptom resolution or decannulation was achieved in all patients in whom prolapse was the source of obstruction. Statistically significant differences were found when anterior vs posterior graft utilization was compared. Conclusions Arytenoid prolapse is a cause of airway obstruction following laryngotracheoplasty. Subtle airway complaints and decannulation failures are common features. Both endoscopic and open procedures can successfully treat arytenoid prolapse. Potential etiologies are discussed.

Laryngotracheal reconstruction with posterior costal cartilage grafts: Outcomes at a single institution

To describe our outcomes after laryngotracheal reconstruction that required posterior costal cartilage grafting focused on decannulation rates and complications. Case series with chart review. Charts were reviewed on 58 patients. Operation specific and overall decannulation rates were determined. Complications were reviewed and correlated with technique of graft placement. Available voice outcomes were reviewed. Forty-eight patients were included. There was no statistically significant correlation between degree of stenosis and rate of decannulation. The overall decannulation rate, regardless of number of surgeries performed, was 96 percent. The relative risk for complications was higher among children who had a sutured versus a sutureless flanged posterior graft (RR = 2.5, P < 0.01). The most common voice anomaly was supraglottic compression. Operation-specific decannulation rates are not significantly different with increasing disease severity, although the power to detect small differences in this study is low. Sutureless graft placement is associated with a lower complication rate. Supraglottic compression is a common postoperative compensatory vocal behavior and may correlate with disease severity.

Duration and extent of dysphagia following pediatric airway reconstruction

Patients who undergo open airway reconstruction procedures are likely to experience some degree of post-operative dysphagia. This retrospective review describes the duration of post-operative dysphagia and the use of compensatory strategies in a group of 30 pediatric patients. A retrospective chart review of pediatric patients referred for post-operative swallowing assessment following airway reconstruction during a six-month period was completed. Age, sex, surgical procedure, stent type, co-morbid factors, duration of dysphagia, and use of compensatory dietary modifications and swallowing strategies was summarized and compared. Dysphagia was generally of short duration (1-5 days) in patients undergoing single stage procedures with anterior or anterior/posterior grafts. Duration of swallowing difficulty was increased in patients undergoing posterior grafts in combination with T tubes (10-14 days). The longest duration of difficulty (>2 weeks) occurred in patients who had anterior and posterior grafting with T tubes, combined with additional procedures such as vocal fold lateralization, epiglottic petiole repositioning, and/or arytenoidectomy. There was a greater likelihood of oral feeding difficulty post-operatively in patients presenting with pre-operative feeding issues such as oral aversion or specific texture refusal, and the pre-morbid need for supplemental tube feeding to supplement oral intake. Compensatory swallowing strategies were effective in decreasing aspiration associated with swallowing in oral feeders post-operatively, and in facilitating return to baseline swallowing skills. The duration of dysphagia overall was increased in patients undergoing anterior/posterior grafts in conjunction with in-dwelling T tubes, especially when combined with additional procedures. Compensatory strategies to assist with swallowing were found to be effective in the post-operative phase and included the use of a modified supraglottic swallowing sequence to assist with compensatory airway closure during swallowing in conjunction with diet modifications. Post-operative feeding difficulty occurred in patients with pre-existing feeding issues such as oral aversion and/or texture resistance regardless of reconstructive surgical procedure type.

Estudo sobre a associação de cerâmica a plasma rico em plaquetas na coluna vertebral de ratos

OBJETIVO: Analisar o efeito osteoindutor dos fatores de crescimento contidos no plasma rico em plaquetas (PRP) quando associados a cerâmicas no processo de fusão na coluna vertebral de ratos. MATERIAL E MÉTODO: Laminectomia lombar foi realizada em 16 ratos Lewis isogênicos para implantar cerâmica. O PRP foi preparado no ato operatório a partir do sangue de outras duas cobaias.os grupos estudo e controle foram estabelecidos por randomização, recebendo o grupo estudo cerâmica associada a PRP e o controle apenas cerâmica. Os animais foram sacrificados após 10 semanas e as colunas enviadas para análise histopatológica. RESULTADOS: Intensa atividade osteoblástica e osteoclástica e completa reabsorção da cerâmica foram achados no grupo estudo. No grupo controle havia ilhotas de osso em meio a tecido fibroso e cerâmica não reabsorvida. Discussão: Os fatores de crescimento liberados pelas plaquetas agem ligando-se à superfície de osteoblastos e fibroblastos, estimulando a síntese de colágeno para formação de matriz óssea. macrófagos ativados continuam secretando os fatores de crescimento e estimulando a osteogênese. CONCLUSÃO: O uso de PRP associado a cerâmica mostrou maior atividade osteoblástica e osteoclástica e completa reabsorção da cerâmica em relação à enxertia da mesma isoladamente na coluna vertebral de ratos.

Les greffes endothéliales

In recent years, endothelial keratoplasty has become increasingly popular in the management of endothelial pathologies of the cornea. This technique is primarily indicated in pseudophakic keratopathy and Fuchs dystrophy and significantly reduces known complications that occur after penetrating keratoplasty (i.e., major astigmatism, graft junction weakness, ocular surface diseases). Visual recovery is also more rapid. The endothelium is removed using a reverse hook or forceps and replaced by an endothelial graft that also includes a certain stromal thickness. The preparation of the donor graft can be automated by using a microkeratome or can be performed manually on artificial anterior chamber. Although automated dissection techniques have become the most popular approach, thin posterior graft can only be obtained using a manual dissection procedure. Several studies are currently underway to assess the possibility of reducing endothelial cell injury when preparing and inserting the graft. Progress in this specific field of research will greatly encourage future use of endothelial keratoplasty.

Descemet’s Stripping Automated Endothelial Keratoplasty

Taken together, causes of endothelial decompensation represent a major indication for corneal transplantation. Posterior lamellar grafts allow patients with endothelial failure to avoid many of the complications associated with the full thickness penetrating keratoplasty. Evolving over the last decade, Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK) represents the latest incarnation of posterior lamellar grafting techniques. This article contains four case reports from the cornea clinic where the author is a resident, and a review of literature highlighting the benefits of posterior lamellar grafting.

Outcomes of Pediatric Posterior Graft Laryngotracheoplasty

Objective 1) Determine the operation specific decannulation rate of patients who required posterior costal cartilage grafting (PCCG) in the management of laryngeal stenosis. 2) Describe the complications associated with PCCG laryngotracheoplasty. 3) Describe voice outcomes for selected patients. Methods A retrospective review was performed on all cases of posterior graft laryngotracheoplasty (LTP) performed by the 2 senior authors over a 9-year period at a tertiary care children's hospital. Results There were 42 total patients. The operation specific decannulation rates were 100% (3/3) for Myer-Cotton grade II SGS, 75% (20/26) for grade III, and 60% (3/5) for grade IV. For posterior glottic stenosis (PGS), it was 57% (4/7) and for PGS with grade II SGS, it was 60% (6/10). There was no significant difference (p=0.727) among these groups. The overall decannulation rates were 100% (3/3), 96% (25/26), and 100% (5/5) for Myer-Cotton grades II, III and IV. For PGS, it was 83% (5/6), and for PGS with grade II SGS, it was 100% (8/8). There was no significant difference (p=0.527) among these groups. The relative risk for complications was higher among children who had a sutured vs. a sutureless posterior graft (RR= 2.7, p&lt;.01). The most commonly seen compensatory vocal behavior was supraglottic dysphonia. Conclusions Operation-specific decannulation rates are not significantly different with increasing disease severity, although the power to detect small differences in this study is low. PCCG via a sutureless technique is associated with a lower complication rate. Supraglottic dysphonia is a common compensatory vocal behavior after PCCG LTP.

Atlantoaxial Transarticular Screw Fixation With Posterior Wiring Using Polyethylene Cable

A comparative retrospective study on the posterior graft union and the facet fusion in atlantoaxial transarticular screw fixation. To evaluate the posterior graft union and the facet fusion in atlantoaxial transarticular screw fixation when a polyethylene (PE) cable was used in rheumatoid and nonrheumatoid patients. In atlantoaxial transarticular screw fixation, metal wires or cables for posterior bone graft fixation can cause intraoperative or delayed spinal cord compression. PE cables do not have the risk, but there has been no comparative report. Also, a precise evaluation on the posterior graft union and the facet fusion has not been reported. Thirty-eight patients who submitted to atlantoaxial transarticular screw fixation and posterior bone graft without any concomitant operation were followed up for more than 2 years. The posterior graft union and the facet fusion were evaluated by functional radiographs and computed tomography scans. Seven patients showed the posterior graft nonunion. All of them were rheumatoid patients and received PE cable wiring for posterior internal fixation. However, 5 of the 7 cases presented stable C1-C2 with the facet fusion demonstrated by functional radiographs and computed tomography scans, achieving an overall fusion rate of 95%. In atlantoaxial transarticular screw fixation, the use of PE cable and rheumatoid background are 2 of the unfavorable factors for the posterior graft union. However, atlantoaxial transarticular screws can bring the facet fusion despite the posterior graft failure in such cases.

POSTERIOR REDUCTION AND FIXATION OF AN UNSTABLE JEFFERSON FRACTURE WITH C1 LATERAL MASS SCREWS, C2 ISTHMUS SCREWS, AND CROSSLINK FIXATION

Abstract Objective: We sought to describe a modified technique for the reduction and stabilization of unstable Jefferson fractures. Clinical Presentation: We present the case of an isolated unstable Jefferson fracture in a 33-year-old woman. The patient was the victim of a motor vehicle accident. Her neurological examination was normal. A cervical computed tomographic scan revealed an isolated Jefferson fracture that we thought to be unstable when we applied the Spence criteria. Technique: The fracture was treated by a technical variant of C1–C2 posterior fixation with compression on the rods by means of a crosslink connector, allowing the reduction of the atlantoaxial lateral mass overhanging. C1–C2 fusion with posterior iliac crest bone graft was added. Conclusion: The 1-year radiological follow-up evaluation showed a complete consolidation of the fracture lines and atlantoaxial stability. This technique could be an option for the reduction and stabilization of the unstable Jefferson fractures.

Arthroscopic posterior cruciate ligament reconstruction using bioabsorbable cross-pin femoral fixation: a technical note

There are many methods for fixation of the posterior cruciate ligament grafts. We introduce a new surgical technique that provides more secure femoral and tibial fixation of a tibialis posterior allograft. The tendon was prepared as a four-stranded graft. The tibial tunnel was made using a standard trans-tibial technique. A femoral tunnel was prepared through a low anterolateral portal. The graft was inserted into the femoral tunnel through the anterolateral portal and TransFix (Arthrex, Naples, FL) was fixed at the femur. Four stands of the graft were passed through the tibial tunnel and IntraFix (DePuy Mitek, Raynham, MA) was fixed at the tibia.

The management of a severely resorbed edentulous maxilla using a bone graft and a CAD/CAM-guided immediately loaded definitive implant prosthesis: A clinical report

Functional reconstruction of an occlusion with severe residual ridge resorption is a clinical challenge. Removable prostheses are unsuccessful in situations with severe bone resorption. A patient with an edentulous maxilla received bone grafts from the anterior iliac crest to augment the maxillary alveolar residual ridges. The maxilla underwent bilateral sinus lift in the posterior area and onlay bone graft on the anterior maxilla using platelet-rich plasma. Eight endosseous implants were placed using a CAD/CAM surgical template approximately 6 months after the bone augmentation procedure. A prefabricated definitive implant-supported fixed complete denture was connected immediately after implant placement using a CAD/CAM-guided surgical implant placement protocol.

The Use of AlloDerm in the Reconstruction of Full-Thickness Eyelid Defects

Purpose: To demonstrate the potential for the use of AlloDerm as a posterior lamellar graft in the reconstruction of full-thickness lid defects. Method: In our case series, we evaluated the surgical outcome of three consecutive patients, two with an upper eyelid defect and one with a lower eyelid defect who underwent lid reconstruction using AlloDerm grafts. Results: AlloDerm was readily taken up into the wound defect, with complete coverage of its bulbar surface by conjunctiva. In all the cases, the cornea was not affected by its contact to the AlloDerm. A mucocutaneous junction formed over the margin of the AlloDerm graft with good cosmesis. Conclusion: AlloDerm has the potential to act as an effective posterior lamellar substitute in situations where there is an adequate amount of skin muscle cover available to drape over it. It is rigid enough to replace tarsus and its structure behaves as a scaffold allowing conjunctiva to readily grow over it.

101. High Grade Spondylolisthesis Treated with Posterior Decompression, Posterolateral Fusion and Fibular Dowel Grafting

101. High Grade Spondylolisthesis Treated with Posterior Decompression, Posterolateral Fusion and Fibular Dowel Grafting

Reconstruction of Chronic Achilles Tendon Defects With Posterior Tibial Perforator Flap and Soleus Tendon Graft: Clinical Series

Reconstruction of Chronic Achilles Tendon Defects With Posterior Tibial Perforator Flap and Soleus Tendon Graft: Clinical Series

Anatomical comparative study of two vascularized bone grafts for the wrist

Atrophic scaphoid non-union and lunate necrosis can be treated with vascularized bone grafting; through a posterior approach as described by Zaidemberg, based on a supraretinacular artery, or through an anterior approach, based on the volar carpal artery, according to Kuhlmann's procedure. The aim of our study was to determine the area covered by each of these two grafts and their respective future applications. Fifteen hands from eight adult human cadavers, free of any scar, were dissected after injection of colored fluid latex, through dorso-radial approach for Zaidemberg's graft and through volar approach for Kuhlmann's. We observed the morphological parameters of the pedicles and the arc of rotation of each flap. The volar vascularized graft had a constant origin and it could be transferred to the scaphoid, the lunate and the scapholunate joint. The posterior graft of Zaidemberg was technically more difficult to harvest because of the anatomical variations. It made it possible to reach the scaphoid, the trapezium and the scaphotrapeziotrapezoid joint line. Both these two vascularized bone grafts represent interesting procedures for treatment of scaphoid non-union or lunate necrosis, or intracarpal bones arthrodesis. They bring various possibilities of bone covering, related to specific area of mobilization and are not opposite procedures, but have different targeted indications. One must better define the respective places of the vascularized bone grafts, compared with the traditional free (non-vascularized) graft.

Microkeratome Preparation of Lamellar Corneal Grafts

To evaluate the thickness and viability of microkeratome-prepared lamellar corneal grafts in cold storage. Ten human corneas were sectioned with a mechanical microkeratome with a 350-microm depth head and stored in Optisol GS at 4 degrees C for 2 days to simulate an eye bank scenario. Central corneal thickness before and after mechanical microkeratome sectioning was measured by ultrasonic pachymetry. Endothelial cell viability was evaluated by trypan blue and alizarin red staining. Total corneal thickness immediately before microkeratome dissection was 562 +/- 51 microm. Anterior and posterior graft thicknesses were 296 +/- 111 microm and 270 +/- 74 microm, respectively, immediately after dissection, and 282 +/- 38 microm and 429 +/- 31 microm, respectively, 2 days after storage. There was significant swelling in the posterior (P=0.005) but not the anterior grafts (P=0.386). The percentage of devitalized endothelial cells was 3.0% +/- 1.2%. Corneal lamellar grafts may possibly be precut in a centralized facility and stored cold before further distribution.

Microkeratome Versus Femtosecond Laser Predissection of Corneal Grafts for Anterior and Posterior Lamellar Keratoplasty

To compare 2 different techniques for predissection of human anterior and posterior lamellar corneal grafts for eye bank storage. A mechanical microkeratome (group 1, N = 5) and a femtosecond laser (group 2, N = 5) were used to dissect intended 350-microm-deep lamellar planes in deepithelialized donor corneas mounted on an artificial anterior chamber. These corneas were replaced in Optisol GS at 4 degrees C postoperatively and examined 2 days later to simulate a clinical scenario. Ultrasonic pachymetry of corneal lamellar sections was measured before and after separation of the lamellar grafts. Group 1 sections were separated by the mechanical microkeratome, whereas group 2 sections were manually separated 2 days after laser dissection. Endothelial cell viability was evaluated in posterior grafts. Total corneal thicknesses immediately before dissection were 559 +/- 61 (group 1) and 578 +/- 79 microm (group 2; P = 0.46). Immediate postdissection anterior and posterior graft thicknesses were 361 +/- 68 and 203 +/- 74 microm (group 1), respectively. Achieved anterior and posterior graft thicknesses 2 days later were 282 +/- 44 and 413 +/- 35 microm (group 1) and 324 +/- 112 and 397 +/- 51 microm (group 2), respectively. Percentage of devitalized endothelial cells were 3.4% +/- 1.6% (group 1) and 1.6% +/- 1.2% (group 2; P = 0.35). Centralized predissection by both techniques, cold storage, and shipping by airmail results in viable grafts without significant endothelial cell loss 2 days later.

Anterior and Posterior Cartilage Graft Dimensions in Successful Laryngotracheal Reconstruction

To describe the dimensions of cartilage grafts used for successful laryngotracheal reconstruction, with the goal of establishing appropriate sizes for "off-the-shelf" tissue-engineered cartilage grafts. A retrospective review of prospectively maintained operative illustrations of a single surgeon's experience. Two tertiary children's hospitals. A consecutive sample of 54 patients (tracheotomized or intubated) with a diagnosis of subglottic stenosis. Each patient underwent anterior (n = 30), posterior (n = 3), or anterior and posterior (n = 22) laryngotracheal reconstruction. Rib cartilage was used in 51 patients and thyroid cartilage was used in 3 patients. Successful or failed extubation. Of the 54 patients, 48 (89%) were successfully decannulated. The mean +/- SEM length of the anterior graft was 20.7 +/- 10.3 mm, and the mean width of the anterior graft was 7.7 +/- 2.5 mm. The mean length of the posterior graft was 13.9 +/- 2.9 mm, and the mean width of the posterior graft was 4.2 +/- 0.9 mm. With the prospect of tissue-engineered cartilage implants becoming available for laryngotracheal reconstruction, the most appropriate templates for designing these implants should be based on the geometric dimensions of grafts carved from native tissues in cases that have been successfully decannulated. Based on our analysis, the use of 2-mm increments for the posterior grafts suggests a set of molds that are 2, 4, and 6 mm wide and 22 mm long. Using 2 x 2-mm increments for the anterior grafts indicates that 36 mold sizes will be sufficient for 90% of predicted cases.

Descemet's stripping with endothelial keratoplasty in 200 eyes

To describe early challenges and techniques to promote donor tissue adherence in Descemet's stripping with endothelial keratoplasty (DSEK). Price Vision Group, Indianapolis, Indiana, USA. The first 200 consecutive cases of DSEK performed by a single surgeon were analyzed retrospectively. Follow-up was 7 to 20 months for 124 eyes and 2 to 6 months for 76 eyes. The surgical technique consisted of stripping Descemet's membrane and endothelium from the recipient's central cornea and transplanting an 8.0 to 9.0 mm disc of donor endothelium and posterior stroma through a 5.0 mm incision, with sutures used only to close the incision. The most frequent challenge was inadequate donor attachment. Using techniques to remove fluid from the donor-recipient graft interface, the donor detachment rate in the last 64 cases was 6%, with half attributable to patient eye rubbing. Detached grafts were reattached by injecting an air bubble to press the donor against the recipient cornea. There were 7 primary graft failures, with only 1 occurring in the second 100 cases, which primarily used microkeratome-dissected donor tissue. Other complications were infrequent and included pupillary block glaucoma (1), aqueous misdirection syndrome (1), and cataract development in 2 of 27 phakic eyes. The DSEK procedure was performed safely before and after laser in situ keratomileusis (1 each). Early outcomes in the initial 200 consecutive DSEK procedures suggest the technique provides significant advantages over penetrating keratoplasty, including more rapid healing, more predictable refractive outcomes, and better retention of corneal strength and integrity. Although donor adherence was more challenging, DSEK was technically easier and should be less traumatic to anterior chamber structures than earlier posterior grafting techniques.