Graft Displacement Research Articles

Biomechanical evaluation of an allograft fixation system for ACL reconstruction.

The purpose of this study was to compare the biomechanical stability, especially graft slippage of an allograft screw and a conventional interference screw for tibial implant fixation in ACL reconstruction. Twenty-four paired human proximal tibia specimens underwent ACL reconstruction, with the graft in one specimen of each pair fixed using the allograft screw and the other using the conventional interference screw. Specimens were subjected to cyclic tensile loading until failure. The two fixation methods did not show any statistical difference in load at graft slippage (p = 0.241) or estimated mean survival until slippage onset (p = 0.061). The ultimate load and the estimated mean survival until failure were higher for the interference screw (p = 0.04, and p = 0.018, respectively). Graft displacement at ultimate load reached values of up to 7.2 (interference screw) and 11.3mm (allograft screw). The allograft screw for implant fixation in ACL reconstruction demonstrated comparable behavior in terms of graft slippage to the interference screw but underperformed in terms of ultimate load. However, the ultimate load, occurring at progressive graft slippage, may not be considered a direct indicator of clinical failure.

Biomechanical Analysis of Posterior Open-Wedge Osteotomy and Glenoid Concavity Reconstruction Using an Implant-Free, J-Shaped Iliac Crest Bone Graft

Background: Posterior open-wedge osteotomy and glenoid reconstruction using a J-shaped iliac crest bone graft showed promising clinical results for the treatment of posterior instability with excessive glenoid retroversion and posteroinferior glenoid deficiency. Purpose: To evaluate the biomechanical performance of the posterior J-shaped graft to restore glenoid retroversion and posteroinferior deficiency in a cadaveric shoulder instability model. Study Design: Controlled laboratory study. Methods: A posterior glenoid open-wedge osteotomy was performed in 6 fresh-frozen shoulders, allowing the glenoid retroversion to be set at 0°, 10°, and 20°. At each of these 3 preset angles of glenoid retroversion, the following conditions were simulated: (1) intact joint, (2) posterior Bankart lesion, (3) 20% posteroinferior glenoid deficiency, and (4) posterior J-shaped graft (at 0° of retroversion). With the humerus in the Jerk position (60° of glenohumeral anteflexion, 60° of internal rotation), stability was evaluated by measuring posterior humeral head (HH) translation (in mm) and peak translational force (in N) to translate the HH over 25% of the glenoid width. Glenohumeral contact patterns were measured using pressure-sensitive sensors. Fixation of the posterior J-graft was analyzed by recording graft micromovements during 3000 cycles of 5-mm anteroposterior HH translations. Results: Reconstructing the glenoid with a posterior J-graft to 0° of retroversion significantly increased stability compared with a posterior Bankart lesion and posteroinferior glenoid deficiency in all 3 preset degrees of retroversion (P < .05). There was no significant difference in joint stability comparing the posterior J-graft with an intact joint at 0° of retroversion. The posterior J-graft restored mean contact area and contact pressure comparable with that of the intact condition with 0° of retroversion (222 vs 223 mm2, P = .980; and 0.450 vs 0.550 MPa, P = .203). The mean total graft displacement after 3000 cycles of loading was 43 ± 84 µm, and the mean maximal mediolateral graft bending was 508 ± 488 µm. Conclusion: Biomechanical analysis of the posterior J-graft demonstrated reliable restoration of initial glenohumeral joint stability, normalization of contact patterns comparable with that of an intact shoulder joint with neutral retroversion, and secure initial graft fixation in the cadaveric model. Clinical Relevance: This study confirms that the posterior J-graft can restore stability and glenohumeral loading conditions comparable with those of an intact shoulder.

Preliminary Approach for Open Lateral Window Technique for Successful Maxillary Sinus Augmentation in the Unrepairable Wide Perforation Area of Schneiderian Membrane

During maxillary sinus augmentation (MSA), bone graft particles displaced through the perforated site can block the ostium and become a risk factor for maxillary sinusitis. The purpose of this case report is to introduce a novel approach for successful lateral MSA performed in the unrepairable perforation area of Schneiderian membrane. In a total of three patients, including two who were unintentionally treated with a split-mouth design, the Schneiderian membrane was irreparably perforated during the sinus floor elevation. After bone grafting was performed on only the sinus floor, the open lateral window technique was performed in which the upper part of the lateral window was opened. After the procedure, unexpectedly, the patient showed transient nasal bleeding, but no unusual clinical events. Most of the bone graft substitutes were not displaced and the exposed portion was covered with a soft tissue. In the sinus graft, clotting of blood, supplied from the perforated Schneiderian membrane and the buccal flap through the open lateral window, appeared to prevent graft displacement. Within the limitations of present case reports, these patients showed that MSA via the open lateral window technique was possible even with a widely perforated Schneiderian membrane that could not be repaired.

Biomechanical comparison between various screw fixation angles for Latarjet procedure: a cadaveric biomechanical study.

The Latarjet procedure is a reliable treatment for the management of anterior glenohumeral instability with glenoid bone loss. However, the biomechanical properties of different fixation angles between screw and glenoid surface (α angle) have rarely been studied. The aim of the study was to investigate and compare the fixation stability, failure load, and failure mechanism between different α angles for Latarjet procedures, which were performed on cadaver specimens. Twenty-four shoulder specimens (8 in each of 3 groups) were dissected free of all soft tissue, and a 25% glenoid defect was created. The coracoid process was osteomized and fixed with 2 screws at 3 different α angles: 0° (group A), 15° (group B), and 30° (group C). Specimens were mounted to a testing apparatus, and cyclic loading (100 cycles at 1Hz) was applied with a staircase protocol (50, 100, 150, and 200N). Gross graft displacement and interface displacement were measured. The ultimate failure loads and failure mechanisms were recorded. There was no significant difference in gross displacement under any cyclic load between 3 groups. However, a significant larger interface displacement was noted in group C than in group A in 150-N cyclic loading (P=.017). Under failure strength testing, all 24 specimens failed because of screw cutout from the glenoid, and the ultimate failure load was similar among the three groups. Compared with the 0° α angle, the displacement after cyclic loading did not significantly increase when the α angle was increased to 15° but significantly increased at 30° for Latarjet procedures, which were performed on cadaver specimens. The results suggest that surgeons should apply the screws as parallel as possible to the glenoid surface when performing the Latarjet procedure. Although mild deviation may not reduce fixation stability, α angles greater than 30° should be avoided.

A Combination Method of Costal Cartilage Injection Techniques for Augmentation Rhinoplasty.

The multiple toothpick-shaped costal cartilage (MTCC) injection technique was introduced as an improvement based on the free diced costal cartilage (FDCC) injection technique for augmentation rhinoplasty. However, radix irregularities may occur when using the MTCC technique. Considering that the FDCC grafts are easier to shape at the nasal radix, we adopted a combination method of the 2 techniques to achieve natural and smooth contour. Four patients accepted this method for augmentation rhinoplasty. Through a unilateral marginal incision, the costal cartilage grafts were injected for nasal augmentation at the subperiosteal plane. The FDCC grafts and the MTCC grafts were used for nasal radix and dorsum augmentation, respectively. Nasal contour was adjusted by external shaping. The follow-up ranged from 24 to 43 months. All patients were satisfied with the surgical outcome. There were no major complications occurred during the follow-up. One patient underwent rasping revision due to her own beauty-appreciation changes. The combination method can take advantages of the FDCC and MTCC injection techniques. It can effectively lower the incidence of contour irregularities and graft displacement. Meanwhile, it is easy to perform without special procedure, and is time-saving and cartilage-saving.

Application effects of feedforward control theory in the rollover bed treatment of mass patients with burn-explosion combined injury

Objective: To explore the application effects of feedforward control theory in the rollover bed treatment of mass patients with burn-explosion combined injury. Methods: A retrospective observational research was conducted. From June 13 to 14, 2020, 15 patients with severe burn-explosion combined injury caused by liquefied natural gas tank car explosion and conforming to the inclusion criteria were admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine. There were 13 males and 2 females, aged 33-92 (66±17) years. All the patients were treated with rollover bed from 48 h post admission, and the feedforward control theory was introduced, including establishing a special feedforward control management team for rollover bed, clarifying the duties of the medical staff in the rollover bed treatment of patients, implementing the cooperation strategy of multidisciplinary physician, training and examining for 80 nurses in the temporarily organized nurse team in the form of "rollover bed workshop", and formulating the checklist and valuation list of rollover bed treatment for continuous quality control. The frequency and the total number of turning over, and successful rate of one-time posture change with the rollover bed of patients within 30 days of admission were recorded, the occurrences of adverse events caused by improper operation for the rollover bed during the treatment were observed, including respiratory and cardiac arrests, treatment interruption, unplanned extubation, bed falling, and skin graft displacement. The lowest levels of arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2), the number of patients with oxygenation index>300 mmHg (1 mmHg=0.133 kPa), and the occurrence of acute respiratory distress syndrome (ARDS) of patients within 2 days of admission and on the 30th day of admission were recorded. Results: Within 30 days of admission, the patients were turned over with the rollover bed for 2 to 6 times each day, with a total of 1 320 turning over operations, the successful rate of one-time posture change reached 99.9% (1 319/1 320), and no adverse event occurred. Within 2 days of admission, the lowest levels of PaO2 and PaCO2 of the patients were (100±19) and (42±4) mmHg, respectively, and the number of patients with mild, moderate, and severe ARDS were 10, 2, and 3, respectively, and none of the patients had oxygenation index>300 mmHg. On the 30th day of admission, the lowest levels of PaO2 and PaCO2 of the patients were (135±28) and (37±8) mmHg, respectively, 3 patients developed moderate ARDS, 1 patient developed severe ARDS, and 11 patients had oxygenation index>300 mmHg. Conclusions: The introduction of feedforward control theory in the treatment of rollover bed of mass patients with burn-explosion combined injury can ensure safe and successful completion of turning over with the rollover bed, promote the repair of burn wound, and improve respiratory function, and therefore improve the treatment quality of patients.

Visual deterioration after endonasal endoscopic skull base surgery: causes, treatments, and outcomes.

Visual deterioration after endoscopic endonasal transsphenoidal surgery (EETS) for sellar and parasellar masses is a rare but serious complication caused by either compressive or ischemic mechanisms. Timely diagnosis and intervention may restore vision if instituted appropriately. The associated risk factors and their relation to the success of intervention are not well understood. The authors examined a series of 1200 consecutive EETS cases performed by the senior author at Weill Cornell/NewYork-Presbyterian Hospital from 2010 to 2020. Cases with postoperative visual deterioration were identified. Pre- and postoperative clinical data, mechanism of visual decline, latency to intervention, and long-term visual outcome were retrospectively collected and analyzed with appropriate statistical methods. Twenty-one patients (1.75%) complained of early postoperative visual deterioration. The most common pathology associated with postoperative visual loss was craniopharyngioma (7.69%), followed by meningioma (5.43%) and then pituitary adenoma (1.94%). Timely intervention restored vision in 81% of patients for a 0.33% rate of permanent visual deterioration. Average time to visual deterioration was 28.8 hours, and over 70% of patients experienced vision loss within the first 13 hours. Compressive etiology (n = 11), consisting of either hematoma (n = 8) or graft displacement (n = 3), occurred 7.3 hours and 70.3 hours after surgery, respectively, and was more common in adenomas. Acute postoperative visual deterioration was more common in firm closures (4.78%) compared with soft closures (1.03%; p = 0.0006). Ischemic etiology (n = 10) occurred 10.3 hours after surgery and was more common with craniopharyngiomas and meningiomas (p = 0.08). Sixteen patients (76.2%) underwent early reoperation to explore and decompress the optic apparatus. Vision was restored to baseline after reoperation in all 11 compressive cases, whereas 6/10 ischemic cases improved with supplemental oxygen and hypervolemic hypertensive therapy (p = 0.02). Fluid expansion from 8 to 16 hours (p = 0.034) and systolic blood pressure elevation from 32 to 48 hours (p = 0.05) after surgery were significantly higher in those ischemic patients who recovered some vision compared with those with persistent visual deficits. Visual deterioration after EETS is a rare event but can be effectively treated if acted upon appropriately and in a timely fashion. Compressive etiology is reversible with early reoperation. Ischemic etiology can be successfully treated in roughly half of cases with supplemental oxygen and hypertensive hypervolemic therapy but may result in permanent visual deterioration if not instituted appropriately or if delayed with unnecessary exploratory surgery.

Comparison of nano-hydroxyapatite/polyamide 66 bioactive support and autologous iliac bone in bone grafting and fusion for elderly patients with lumbar tuberculosis

To investigate the safety of nano-hydroxyapatite/polyamide 66 (n-HA/PA66) bioactive support in bone grafting and fusion for elderly patients with lumbar tuberculosis, and to analyze its effectiveness and advantages by comparing with autologous iliac bone grafting. A retrospective analysis was performed on 48 elderly patients with lumbar tuberculosis who met the selection criteria between January 2017 and January 2020. The patients all underwent one-stage posterior pedicle screw internal fixation combined with anterior lesion removal and bone grafting and fusion, of which 23 cases applied n-HA/PA66 bioactive support+allogeneic bone graft (n-HA/PA66 group) and 25 cases applied autologous iliac bone graft (autologous iliac bone group). There was no significant difference between the two groups in gender, age, bone density, disease duration, lesion segment, and preoperative pain visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, and Cobb angle ( P>0.05). The operation time, intraoperative blood loss, and postoperative complications, as well as the VAS score, JOA score, American Spinal Injury Association (ASIA) spinal cord injury grading, Cobb angle, and bone fusion were recorded and compared between the two groups. The operations were completed successfully in both groups. n-HA/PA66 group had significantly less operation time and intraoperative blood loss than the autologous iliac bone group ( P<0.05). All patients were followed up 12-24 months, with an average of 15.7 months. And the difference in follow-up time between the two groups was not significant ( P>0.05). Postoperative complications occurred in 3 cases (13%) in the n-HA/PA66 group and 10 cases (40%) in the autologous iliac group, and the difference in the incidence of complications between the two groups was significant ( χ 2=4.408, P=0.036). The postoperative VAS scores and JOA scores significantly improved when compared with the preoperative scores in both groups ( P<0.05), and the difference was significant ( P<0.05) between 2 weeks after operation and the last follow-up. The difference in VAS score at 2 weeks after operation was significant between the two groups ( P<0.05), and there was no significant difference ( P>0.05) at the other time points. At last follow-up, according to the ASIA grading, the effective improvement rate was 86% (18/21) in the n-HA/PA66 group and 90% (18/20) in the autologous iliac group, with no significant difference ( χ 2=0.176, P=0.675). Imaging review showed that grade Ⅰ bony fusion was obtained in both groups, and the fusion time of bone graft in the n-HA/PA66 group was significantly longer than that in the autologous iliac bone group ( P<0.05). There was no significant difference in the Cobb angle at each time point between the two groups ( P>0.05). No recurrence of tuberculosis, loosening or fracture of the internal fixator, or displacement of the bone graft was observed during follow-up. In elderly patients with lumbar spine tuberculosis, the n-HA/PA66 bioactive support combined with allogeneic bone graft can effectively restore and maintain the fusion segment height and physiological curvature of the lumbar spine, and the fusion rate of bone graft is similar to that of autologous iliac bone, which can achieve better effectiveness.

Early post-operative performance of an anatomically designed hybrid thread interference screw for ACL reconstruction: A comparative study

Although the anterior cruciate ligament (ACL) reconstruction using interference screw is a well-accepted surgical procedure, patients still suffer graft failure in the initial rehabilitation phase. Graft fixation stability of a newly designed anatomical hybrid thread tapered interference screw (AHTTIS) was compared with a conventional standard one (CSIS) by conducting in-vitro mechanical tests. According to the CSIS manufacturer’s instruction, eight tapered bone tunnels, matching AHTTIS geometry, and eight straight cylindrical tunnels were drilled in artificial bone blocks. Bovine tendon grafts were fixed using AHTTIS and CSIS in their corresponding bone tunnels. Each graft was subjected to a pre-load, a dynamic cyclic sinusoidal tensile load, and a tensile pullout load. Aggregate graft displacement relative to the bone tunnel under dynamic cyclic load, load corresponding to a 3 mm displacement; load and displacement at yield and ultimate failure of the graft; and graft-bone-screw stiffness resulted from pullout tests were recorded. There were no significant differences between recorded parameters of the two groups, except the graft displacements relative to the bone tunnel at ultimate failure load (8.35 ± 3.03 mm versus 5.28 ± 1.37 mm) and at the yield point (7.73 ± 3.02 mm versus 4.59 ± 1.25 mm) (P < 0.05), which were both significantly greater for the AHTTIS group. Considering all tests were made in the worst-case scenario of fixation of an interference screw, i.e., the employed synthetic bone just mimicked cancellous bone, graft fixation with the AHTTIS is practical. However, in the case of employing high strain rate loads on AHTTIS, further considerations are needed to reduce the side effect of slippage of the graft.

Fenestrated Endovascular Aortic Repair With Chimney Graft for Thoracoabdominal Aneurysm.

Thoracoabdominal aneurysms pose technical challenges for endovascular repair due to involvement of visceral and renal vessels. We report a case series of four patients diagnosed with thoracoabdominal aneurysm who underwent complex endovascular repair with Fenestrated Device and chimney grafts (FEVARCh). FEVARCh is a technically feasible approach for repair of thoracoabdominal aneurysms that involve renal, superior mesenteric, and celiac arteries for patients not appropriate for open surgical repair. Further studies are needed to understand the implications of resultant Type 1a endoleaks and strategies to minimize the displacement of the main body graft with adjunct chimneys.

Comparison of two internal fixation systems in lumbar spondylolysis by finite element methods

Background and purposeInternal fixation surgeries are currently the most effective treatments for lumbar spondylolysis, but the optimal fixation method is still on debate. This study was designed to compare the biomechanical characteristics of two fixation methods for lumbar spondylolysis, the pedicle screw-U shape rod (PSUSR) internal fixation system, and the pedicle screw-vertebral plate hook (PSVPH) internal fixation system, through three-dimensional finite element analysis, expecting to provide clinical guidance. MethodsFour finite element models (A, B, C, D) of L4-S1 vertebral body of a female patient were reconstructed by CT image segmentation. (A: intact model. B: spondylolysis model. C: spondylolysis model with PSUSR internal fixation. D: spondylolysis model with PSVPH internal fixation). Six physiological motion states were simulated by applying 500N concentrated force and 10Nm moment load to four models. The biomechanical advantages of the two internal fixation systems were evaluated by comparing the range of motion (ROM), maximum stress, maximum strain, and maximum displacement of the models. ResultsCompared to model B, the ROM decreased by 35.7%-57.1% in model C and 39.7%-64.8% in model D. The maximum displacements of model C and D both decreased. The maximum stresses in both vertebral and the internal fixation system are greater in model C than those in model D. The maximum stress and strain reduction of L5-S1 intervertebral disc in model D was greater than that in model C. Model D restores the articular cartilage stresses to the normal levels of model A. The maximum stress and maximum displacement of the bone graft in model C are greater than those in model D. ConclusionsThe PSVPH internal fixation system has better biomechanical properties than PSUSR internal fixation system in several mechanical comparisons. Experimental results suggest that PSVPH internal fixation system can effectively treat lumbar spondylolysis while preserving segmental mobility, and can be the treatment of choice.

Conjunctival Autograft versus Combined Amniotic Membrane and Mini-Simple Limbal Epithelial Transplant for Primary Pterygium Excision.

PurposeTo compare outcomes of conjunctival autograft (CAG) and combined amniotic membrane with mini-simple limbal epithelial transplant (mini-SLET) after primary pterygium excision.MethodsAll consenting adults with primary pterygium were included in this study. After pterygium excision, patients were randomized to receive either CAG or mini-SLET and both grafts were held in place with fibrin glue. The patients were followed-up at days 1, 3, 7, 14, and 30 and subsequently at the third, sixth, and ninth months. The recurrence rate was considered as the primary outcome measure whereas the operating time, postoperative symptoms, and surgical complications were considered the secondary outcome measures.ResultsThe study comprised of 264 eyes of 264 patients, of which 233 (88%) completed the nine months of follow-up. Of these, 118 (51%) received CAG and 115 (49%) received mini-SLET. The groups were comparable at baseline. Recurrence of pterygium was seen in two (1.6%) eyes in the CAG group and three (2.6%) eyes in the mini-SLET group (P = 0.68). Operative time for mini-SLET (20.33 1.28 min) was significantly higher than that for CAG (12.01 1.26 min) (P 0.001). Graft displacement was observed in one case in group II (P = 0.999). The Lim Bon Siong (foreign body sensation, lacrimation, pain, and irritation) score in the CAG group was statistically significant for all four symptoms at days 1 and 3; however, at day 7, foreign body sensation, pain, and irritation scores were significantly higher for the CAG group.ConclusionIn this study, the overall recurrence rate was very low and comparable between mini-SLET and the established technique of CAG after performing the primary pterygium excision. Despite a longer surgical time, mini-SLET appears to be a viable option for the management of primary pterygium.

Fat Myringoplasty for Small Central Perforation of Tympanic Membrane: A Prospective Study.

In fat myringoplasty, fat harvested from ear lobule is used as graft material for the closure of small size central perforation of tympanic membrane under local anaesthesia. This study was performed over a period of 5years (January 2016-December 2020) on 67 cases who underwent surgery and were willing to participate in the study at our tertiary hospital. Closure of perforation was found in 93% of cases within 2-3months of surgery. Hearing gain was 6.8dB on an average and morbidity was insignificant in successful cases. Fat myringoplasty is a successful yet simple procedure for repair of small size perforations. It is a day-care procedure under local anaesthesia requiring minimal tissue handling. It is also cost effective and has minimum post-operative morbidity. The likely cause of failure are ear infections and graft displacement due to respiratory tract infections. Results of the fat myringoplasty also depend upon the experience of the operating surgeon and cooperation of the patient.

Postoperative Outcomes of Pterygium Excision Surgery with Autograft Using Autologous Blood Versus Conventional Sutures

Introduction: Pterygium is an extremely common ocular condition believed to be occurring due to proliferation and overgrowth of abnormal epithelial and fibrovascular tissue onto the cornea. They are characterized by cellular proliferation, neovascularization, and inflammation. Ultraviolet rays (UVR) induced elastoid degeneration of subepithelial connective tissue, genetic alteration associated altered cytokine expression plays an important role in the pathogenesis of pterygium. The recent treatment entities include conjunctival autograft with good results. The most commonly used means of fixating conjunctival autografts is by sutures or fibrin glue.&#x0D; Aim: This study aimed at comparative assessment of postoperative outcomes of pterygium excision surgery with autograft using autologous blood versus conventional sutures.&#x0D; Methods: Forty post-operative cases of pterygium excision surgery with conjunctival autograft were enrolled in the study and serially followed up. The study included two groups of 20 patients each. Group-A included cases of pterygium excision with autograft using autologous blood, and Group-B included cases of pterygium excision with autograft and sutures. Post-operatively, patients were examined on the 1st, 7th and 30th day to document the graft loss. Graft stability was also assessed on day 1 in both groups. Final comparisons were documented in terms of graft edema, stability and recurrence. Also suture related complications like foreign body sensation, watering, discomfort, granuloma formation and suture abscess were assessed in follow-up.&#x0D; Results: Group-B (suture group) revealed better graft stability whereas displacement of graft was documented in six cases of Group-A. Graft edema was reported in 10 cases from Group A and 7 cases from Group B. On the 30th day, all patients of both groups presented with similar findings. However, subjective discomfort was reported to be more in group-B as compared to group-A during each follow-up.&#x0D; Conclusion: Issue of graft displacement was a critical challenge with autologous blood group (Group A) patients compared to suture-related complications in group B. Looking towards the evidence of less remarkable complications and almost similar outcomes, the surgeons dilemma on pterygium management still persists.

Scapular bone grafting with allograft pin fixation for repair of bony Bankart lesions: A biomechanical study.

BACKGROUNDSevere bony Bankart lesions are a difficult challenge in clinical treatment and research. The current treatment methods consist mostly of Latarjet-Bristow surgery and its modified procedures. While good results have been achieved, there are also complications such as coracoid fracture, bone graft displacement, and vascular and nerve injury.AIMTo analyze the techniques and biomechanical properties of transversely fixing a bone block from the scapular spine using bone allograft pins with suture threads to repair bony Bankart lesions.METHODSFresh human shoulder joint specimens and a cadaver specimen model for scapular bone grafting with allograft pin fixation for repair of bony Bankart lesions were used. When the humeral rotation angles were 0°, 30°, 60° and 90°, and the axial loads were 30 N, 40 N, and 50 N, the humerus displacement was studied by biomechanical experiments.RESULTSWhen the angle of external rotation of the humerus was 0°, 30°, 60°, and 90°, with axial loads of 30 N, 40 N, and 50 N, the data of the normal control group, allograft pin repair group, and titanium alloy hollow screw repair group were compared with each other by the q-test, which showed that there were no statistically differences among the three groups (P > 0.05).CONCLUSIONThe joints repaired with bone block from the scapular spine transversely fixed with allograft bony pins to repair bony Bankart lesions show good mechanical stability. The bone block has similar properties to normal glenohumeral joints in terms of biomechanical stability.

Evaluation of outcome of primary pterygium excision combined with different techniques

To compare different techniques combined with excision in treatment of primary pterygium: Amniotic membrane transplant [AMG], Limbal-conjunctival autograft [CLAG], and mitomycin c with limbal-conjunctival autograft.[MMC+CLAG]: A prospective comparative study was performed in tertiary hospital on 105 patients satisfying the inclusion and exclusion criteria. Combined with excision, 35 eyes each were treated with AMG transplantation [Group 1] and CLAG [Group 2] for closure of defect. In 35 eyes low-dose mitomycin -C [0.02%] was applied on bare sclera for 1 minute and a CLAG was applied thereafter [Group 3]. Patients were followed up for 9 months.Study was conducted from June 2018 to April 2020 on patients of age 26 to 72 years with mean age of 46.3 ± 10 years with 42[40%] male and 63[60%] female. A statistically significant change [ paired t test, p&amp;#60;0.001] was noted in K-horizontal value pre- and post- pterygium surgery. Change in K-vertical pre- and post- surgery was not statistically significant [paired t test, p&amp;#60;0.58]. Pterygium recurred in 3 patients [8.6%] in group 1, 1 patient [2.9%] each in group 2 and 3. Other postoperative complications include graft displacement [5.7%], graft oedema [6.7%] and congestion [9.5%]. A minor case of scleral melting was noted in one patient [2.9%] in group 3. Pterygium excision followed by CLAG and MMC+CLAG are an effective way of reducing recurrence. However close monitoring is required for use of adjuvant MMC.AMG can be reserved in patients with bilateral pterygium, severe limbal stem cell loss and in need of glaucoma surgery.

On Measuring Implant Fixation Stability in ACL Reconstruction.

Numerous methods and devices are available for implant fixation in anterior cruciate ligament (ACL) reconstruction. Biomechanical data indicate high variability in fixation stability across different devices. This study aims to provide a better insight into measuring the structural characteristics and mechanical behavior of ACL implant fixations. Fourteen human tibial specimens with reconstructed ACLs were subjected to progressively increasing dynamic loading until failure. The motions of the tibia, the proximal and distal graft ends, as well as the testing frame and actuator, were continuously recorded via a motion tracking system. Significantly higher displacements of the machine actuator (1.0 mm at graft slippage onset, and 12.2 mm at ultimate load) were measured compared to the displacements of the proximal (0.8 and 4.3 mm, respectively) and distal graft (0.1 and 3.4 mm, respectively) ends. The displacements measured at different sites showed significant correlations. The provided data suggest significant and systematic inaccuracies in the stiffness and slippage of the fixation when using machine displacement, as commonly reported in the literature. The assessment of the distal graft displacement excludes the artifactual graft elongation, and most accurately reflects the graft slippage onset indicating clinical failure. Considering the high displacement at the ultimate load, the ultimate load could be used as a standardized variable to compare different fixation methods. However, the ultimate load alone is not sufficient to qualitatively describe fixation stability.

Comparison of Free Diced and Multiple Toothpick-Shaped Costal Cartilage Injection Techniques for Augmentation Rhinoplasty.

The free diced costal cartilage (FDCC) injection technique has been used in the augmentation rhinoplasty for a long time. In order to lower the incidence of nasal contour irregularities and graft displacement, we developed the multiple toothpick-shaped costal cartilage (MTCC) injection technique. This comparative study was conducted to introduce and assess this new technique. This retrospective analysis included 51 patients who underwent augmentation rhinoplasty with either the FDCC or MTCC injection technique at the 17th Department of Plastic Surgery in the Plastic Surgery Hospital between July 2014 and May 2020. The patients were divided into the FDCC (n = 30, 58.82%) and MTCC (n = 21, 41.18%) groups. General data, postoperative patient satisfaction, complications and revision rate were compared between the groups. Except for the follow-up period, there were no significant differences in general data (age, sex, preoperative dorsum deformity, preoperative rhinoplasty history) between the groups. Postoperative patient satisfaction, complications and revision rate were similar between the two groups. The MTCC injection is a safe and effective technique for augmentation rhinoplasty. Like the FDCC injection technique, the new technique is relatively easy to perform and time-saving with concealed scarring and minimal postoperative edema. Most of its revision surgeries are also easy to perform by simple rasping and reinjection. According to our experience, the new technique may have wider indication as well as lower incidence of nasal contour irregularities and graft displacement. Therefore, we suggest that the MTCC injection technique is reliable and worthy of recommendation. This journal requires that authors assign a level of evidence to each article. 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 .

Acetabular remodeling after graft extrusion, rotation or impaction in Dega and Pemberton acetabuloplasties for developmental dysplasia of the hip.

Traditionally graft displacement following Pemberton and Dega acetabuloplasties involves internal fixation for treatment of developmental dysplasia of hip (DDH). This study was performed to assess the acetabular remodeling by conservative management of graft displacement among patients with DDH. This was a retrospective study of 20 patients 17 (85%) women and 3 (15%) men; mean age 22.90 ± 6.96 months with DDH who underwent Pemberton and Dega acetabuloplasties at King Khalid University Hospital, Riyadh between January 2013 and January 2018. All patients after losing acetabular correction during immediate postoperative period were treated by conservative management. The management involved application of Spica cast for 6 weeks that was trimmed to broomstick cast for an extended period of time and finally replaced by nocturnal abduction brace until normal acetabular index (AI) was achieved. The patients were followed up for a mean period of 44.60 ± 12.36 months. Out of the total, 18 (90%) patients with DDH were successfully treated by conservative management. The mean preoperative AI of 43.70° ± 5.91° improved to 21.35o ± 6.32o at the final follow-up (P < 0.001) which was no different when compared to the mean of unaffected hips (19.70o ± 2.96o; P < 0.44). The mean preoperative CEA of all the patients was negative that improved during the conservative treatment to 29.20° ± 10.0° which was no different when compared with the mean of unaffected (31.70° ± 4.64o; P = 0.32) hips at the final follow-up. doption of less aggressive approach for management of displaced, rotated or impacted autograft following acetabuloplasties among children with DDH was not only a useful conservative approach for remodeling of hips but also obviated the need for additional surgical intervention.

Biomechanical analysis of single-incision anatomic repair technique for distal biceps tendon rupture using tunneling device.

Single-incision biceps tendon repair with an arthrotunneling device has previously been shown to be a safe and effective technique that provides the anatomic restoration of a two-incision approach and a reduced complication profile. This repair provides adequate and comparable fixation to repairs utilizing anchors, buttons, screws, etc., at a lower cost. This study utilized 10 cadaveric specimens. Native and repair specimens were cyclically loaded and graft displacement, flexion/extension (FE) and pronation/supination (PS) moment arms at 12.5° to 152.5° (in 5° increments) before and after repair, and maximum load to failure were measured. The FE and PS moment arms and overall maximum moment arms were both significantly larger in the repaired case than in the native case (p < 0.01). Moment arms for supinated specimens were significantly greater than neutral specimens, which in turn was greater than pronated specimens (p < 0.01). The maximum load up to 10 mm of repair displacement was 214.5.0 ± 66.6 N and the repair displacement due to 1000 cycles of 50 N was 2.56 ± 2.06 mm. The single-incision arthrotunneling technique is a safe and effective repair that recreates the anatomic footprint and biomechanics of the native biceps and has a reduced complication profile compared to a two-incision approach.