Choice Of Fixation Device Research Articles

Biomechanical evaluation of seven fixation methods to treat pubic symphysis diastasis using finite element analysis

BackgroundPubic symphysis diastasis (PSD) hinders the connection between bilateral ischia and pubic bones, resulting in instability of the anterior pelvic ring. PSD exceeding 25 mm is considered disruptions of the symphyseal and unilateral/bilateral anterior sacroiliac ligaments and require surgical intervention. The correct choice of fixation devices is of great significance to treat PSD. This study aimed to evaluate the construct stability and implant performance of seven fixation methods to treat PSD using finite element analysis.MethodsThe intact skeleton-ligament pelvic models were set as the control group. PSD models were simulated by removing relevant ligaments. To enhance the stability of the posterior pelvic ring, a cannulated screw was applied in the PSD models. Next, seven anterior fixation devices were installed on the PSD models according to standard surgical procedures, including single plates (single-Plate group), single plates with trans-symphyseal cross-screws (single-crsPlate group), dual plates (dual-Plate group), single cannulated screws, dual crossed cannulated screws (dual-canScrew group), subcutaneous plates (sub-Plate group), and subcutaneous pedicle screw-rod devices (sub-PedRod group). Compression and torsion were applied to all models. The construct stiffness, symphyseal relative micromotions, and von Mises stress performance were recorded and analyzed.ResultsThe construct stiffness decreased dramatically under PSD conditions. The dual-canScrew (154.3 ± 9.3 N/mm), sub-Plate (147.1 ± 10.2 N/mm), and sub-PedRod (133.8 ± 8.0 N/mm) groups showed better ability to restore intact stability than the other groups (p < 0.05). Regarding regional stability, only single-plate fixation provided unexpected regional stability with a diastasis of 2.1 ± 0.2 mm (p < 0.001) under a compressive load. Under a rotational load, the single-crsPlate group provided better regional angular stability (0.31° ± 0.03°, p < 0.001). Stress concentrations occurred in the single-Plate, sub-Plate, and sub-PedRod groups. The maximum von Mises stress was observed in the single-plate group (1112.1 ± 112.7 MPa, p < 0.001).ConclusionThe dual-canScrew fixation device offers ideal outcomes to maintain stability and prevent failure biomechanically. The single-crsPlate and dual-Plate methods effectively improved single-Plate device to enhance regional stability and disperse stresses. The subcutaneous fixation devices provided both anterior pelvic ring stability and pubic symphysis strength.

Extra-Articular Proximal and Distal Metaphyseal Tibial Fracture Fixation by Intramedullary Expert Nail and Locking Plate: A Prospective Study

Background: Extra-articular proximal and distal metaphyseal fractures of tibia pose a significant challenge to the surgeons. Debate continues regarding choice of fixation devices. Evaluate these fractures fixation with intramedullary expert tibial nail and extramedullary locking plate and screws.&#x0D; Materials and methods: This is a prospective interventional study which had been conducted in the Department of Orthopaedics &amp; Traumatology, Chittagong Medical College Hospital, Chattogram from July, 2018 to June, 2019. Total 60 cases (30 cases in each group) with proximal and distal metaphyseal tibial fractures (AO/OTA 41A2 to A3 and 43A1 to A3) were taken. Functional assessment was done atleast 6th month of surgery using Tegner Lysholm knee scoring scale and Kaikkonen ankle scale.&#x0D; Results: According to assessment scale, excellent outcome was observed in 20 (66.7%) patients, good in 05 (16.7%), fair in 03 (9.9%) and poor in 2 (6.7%) patients in ETN group while in LPS group, 18 (60%) patients were excellent, 05 (16.7%) good, 04 (14.3%) fair and 03 (9.9%) patients were poor. Difference in functional outcome in both the groups was statistically non-significant.&#x0D; Conclusions: There was no significant difference statistically in functional outcome of patients treated with intramedullary and extramedullary fixation method.&#x0D; JCMCTA 2021 ; 32 (1) : 59-64

The Treatment of Distal Biceps Ruptures: An Overview.

Traumatic lesions of the distal biceps brachii are uncommon. They often result from rapid elbow flexion against resistance. Conservative treatment is only indicated in low-demanding patient and in those who have severe comorbidities. Regarding the surgical approach, two options are available: the single- and the double-incision techniques. The former has been the first to be described and was associated with significant rate of neurologic complications. The second showed less frequent neurologic lesions, but considerable rate of heterotopic ossifications with reduced forearm movement. The choice of fixation device is another important issue. Cortical buttons, transosseous repair, suture anchors, and interference screws have shown satisfactory outcomes. However, cortical buttons have the best mechanical properties. Although a lack of high methodological quality studies emerges in the available literature, three recent systematic reviews and meta-analysis show interesting findings. Surgical reinsertion of the distal biceps brachii yields satisfactory clinical outcomes both with the single- and double-incision techniques. Higher prevalence of nerve injuries is associated with the single-incision techniques, whereas higher prevalence of heterotopic ossification is reported with double-incision techniques. Thus far, there is no sufficient evidence to support one option and the choice is mainly based on surgeon's experience.

Controversies in the intramedullary nailing of proximal and distal tibia fractures.

Management of tibia fractures by internal fixation, particularly intramedullary nails, has become the standard for diaphyseal fractures. However, for metaphyseal fractures or those at the metaphyseal-diaphyseal junction, choice of fixation device and technique is controversial. For distal tibia fractures, nailing and plating techniques may be used, the primary goal of each being to achieve acceptable alignment with minimal complications. Different techniques for reduction of these fractures are available and can be applied with either fixation device. Overall outcomes appear to be nearly equivalent, with minor differences in complications. Proximal tibia fractures can be fixed using nailing, which is associated with deformity of the proximal short segment. A newer technique-suprapatellar nailing-may minimize these problems, and use of this method has been increasing in trauma centers. However, most of the data are still largely based on case series.

Advantages and disadvantages of pinless external fixation

The AO pinless external fixator (PEF) uses trocar tipped clamps to grip the outer tibial cortex rather than pins to transfix it. Its main advantage is to avoid further contamination of the medullary canal in open tibial fractures where a nail may subsequently be used. We tested the anatomical safety of this device and its effect on plastic surgical procedures compared with a standard unilateral external fixator (UEF). The PEF and UEF were placed on two amputated limbs which were then dissected. Structures at risk were traced on ten cadaver limbs. We found that important anatomical structures were endangered by the PEF and that safe zones could not always be defined. The UEF avoided these structures. Plastic surgical approaches were made more difficult by the PEF which imposed limitations on local flap design and endangered the arterial perforators which supply them. We conclude that safety is compromised by the PEF because margins for error are small. It poses additional problems in soft tissue reconstruction and highlights the need for co-operation between plastic surgical and orthopaedic teams in choice of fixation device.

Biomechanical Evaluation of Titanium, Biodegradable Plate and Screw, and Cyanoacrylate Glue Fixation Systems in Craniofacial Surgery

Choice of appropriate fixation after reduction of displaced bone fragments or advancement of osteotomized segments requires knowledge of the maximal force to which these segments can be subjected. The present study was performed to obtain a biomechanical comparison of a variety of resorbable fixation systems as an alternative to metal plates and screws. Sheep cadaver parietal bone segments were osteotomized and fixed with one of six methods of fixation: (A) titanium plates and screws consisting of (1) miniplates and 2.0-mm-diameter screws; (2) midface plates and 1.5-mm screws; (3) microplates and 1.0-mm screws; (B) resorbable systems consisting of combinations of butyl-2-cyanoacrylate glue and biodegradable polylactic acid/polyglycolic acid copolymer plates and 2.0-mm screws as follows: (1) direct glue fixation of segments; (2) resorbable plates fixed to bone segments with cyanoacrylate glue; (3) resorbable plates fixed with resorbable screws. Compression testing was performed upon bone segments advanced and fixed across a central gap, and distraction testing was performed on bone segments fixed in direct contact. Force to failure in both distraction and compression was significantly greater in bone segments fixed with titanium miniplates than with any other method of fixation. Segments fixed with plates and screws, either nonresorbable or resorbable, achieved stronger fixation in distraction than in compression for all plate sizes tested. Resorbable plate and screw fixation was as strong as standard titanium midface and microplating systems in distraction, and stronger than the latter techniques in compression. With compressive forces of relapse, fixation with glue and resorbable plates was as strong as standard titanium midface and microplating systems. However, with distractive forces of relapse, glue fixation of either the bone segments or resorbable plates was weaker than both titanium and resorbable alternatives in which plates and screws were used. These findings may have direct impact on the choice of fixation devices used to support osteotomized or fractured bone segments, which are subjected to persistent muscular and soft-tissue pull.

Complication rate of long bone fractures treated by early stable internal and trans-osseous osteosynthesis

Complications occurring in 94 (24.1%) of 390 operative osteisynthesis were analysed. There were 284 patients with composite (115) and combined fractures of long bones. Complications occurred during recovery in 54 (23.6%) cases of transosseous osteosynthesis and in 40 (24.8%) cases of internal osteosynthesis. Intra-operative complications occurred in 4 cases due to technical errors, e.g. further comminution or vascular injury. Postoperative complications occurred in 7 cases due to inappropriate choice of fixation device, e.g. loss of reduction or fication failure. Postoperative infections predominantly involved the femur and tibia (60.6%). The final outcome was not influenced by local pin tract infection involving either skin, bone or both. There were 15 cases with general complications, e.g. pneumonia, thromboembolism, and decubiti; and 12 with local complications, e.g. toxidermia and marginal wound necrosis. All general complications were associated with restricted patient mobility and were observed 3 times more frequently (6.2%) with internal osteosynthesis than with transosseous osteosynthesis (2.2%). Careful attention to technique will help minimize the complication rate of osteosynthesis.

The Smith-Petersen Nail

ABSTRACT To the Editor:— In reviewing the article, Slipped Capital Femoral Epiphysis, by Drs. Aufranc, Jones, and Turner (198:546, 1966), which was the FRACTURE OF THE MONTH, was struck by the fact that apparently there are a few surgeons in this country who are still using Smith-Petersen nails to fix a slipped capital femoral epiphysis internally. The ensuing complication, distraction of the epiphyseal head by the nail, happens all too frequently with this type of internal fixation. was also surprised at Dr. Aufranc's comment, I think the choice of fixation device is less important than the skill with which the device is employed.It is quite obvious to me and others who have had any experience with the treatment of slipped capital femoral epiphysis, that any type of nail such as the Smith-Petersen, which has to be pounded into a small, hard femoral neck, risks lifting the femoral