Standard Entry Point Research Articles

Determination of the best point of entry of percutaneous insertion of sacroiliac screws depending on patient positioning for surgery: A cadaveric study.

The standard starting point for percutaneous sacroiliac screw insertion was initially determined at the intersection of the line posterior to the anterior superior iliac spine and the line continuing the anatomical axis of the femur. The technique was pioneered in patients lying prone in surgery, although it has been used with patients in the supine position. The optimal starting point for patients in both prone and supine positions remains uncertain. This cadaveric study aimed to determine the best entry point for the percutaneous insertion of sacroiliac screws depending on the patient's positioning for surgery. Kirschner wires (K-wires) were percutaneously inserted into the sacral body of 8th human cadavers. In addition to the so-called standard sacroiliac screw entry point (point A), points located consecutively 1 cm (point B) and 2 cm (point C) cranially from the point along the line, prolonging the femoral axis were also studied. The K-wires were inserted into the studied entry points on the right side in a supine position and on the left side of the same cadaver in a prone position. The placement of the K-wires was assessed using radiographic imaging and cadaver dissection. An analysis of the K-wire placement in the supine position revealed incorrect positioning of 100% of the K-wires inserted at entry point A and 87% at entry point B. All the K-wires inserted in the supine position at entry point C were correctly placed. All K-wires inserted in the prone position were correctly positioned. All 3 studied entry points enabled the correct placement of orthopedic implants for prone position surgery. The best entry point for surgery performed in the supine position was located 2 cm cranially from the standard entry point, along the line prolonging the femoral axis.

Reduction of geometric misfit in straight antegrade humeral nailing by evaluating the effect of entry point angulation using a three-dimensional computational analysis

BackgroundStraight antegrade intramedullary nails are generally inserted utilising the apex as the surgical entry point in accordance with the mechanical axis of the bone. Our objective is to optimise the bone-nail fit in intramedullary nailing by subjecting the surgical entry point to varying angulations in both the mediolateral and anterior-posterior directions via a quantitative fit assessment in each configuration to identify the optimal angulation, defined as the angulation with the lowest occurrence of thin-out to improve nail fitting within the humerus. MethodsComputed tomography (CT) scans from 10 cadaveric humeri models were used to generate three-dimensional bone models. The centreline profile of each humerus model was determined by dividing the humerus into multiple slices and identifying its respective centroid. The guidewire and nail models were then established and inserted into the humerus using the apex as the standard entry point. The bone-nail fit was measured utilising three fit quantification parameters: thin-out distance, nail protrusion volume into the cortical shell and deviation distance (top, middle, bottom) between the nail's longitudinal axis and medullary cavity centroid. FindingsResults revealed a statistically significant association between angulation and occurrence of thin-out (p < .001) and showed that the optimally angulated entry point resulted in decreased cortical breach across the nail insertion depth compared to the standard entry point. InterpretationOur findings suggested that the current straight nail design may require further modifications to optimise the nail trajectory within the medullary canal by decreasing the bone-nail geometric mismatch to potentially maximise its working length.

Successful COVID-19 Contact Tracing of Crew from Two Cargo Ships at the Morowali Seaport, Indonesia.

This study aims to report a successful systematic quarantine of coronavirus disease (COVID-19) to detect Omicron, a new variant of concern, among 2 cargo ships in the Morowali seaport, Indonesia. An international standard entry point protocol had been followed in this study for all crew. Rapid diagnostic tests and whole-genome sequencing (WGS) tests have been conducted to identify Omicron, the variant of concern. Individual characteristics, laboratory result, and vaccine status were collected in this study. On December 9 and 18, 2021, there was an increase of 21 and 22 new cases, respectively, from 2 ships in the seaport. Both ships came from abroad, 43 new cases with a positivity rate increase from 0 to 13.4% and 13.7% within 2 weeks. A polymerase chain reaction (PCR) examination was carried out on all crews and obtained results 21 of the 22 positive COVID-19 crew (95.5%). The monitoring results showed that there was no fever in the entire crew, no symptoms of cough, runny nose, shortness of breath, and other symptoms pointing to COVID-19. Systematic quarantine has successfully contained the large clusters of COVID-19 in the crews of 2 ships and prevented further outbreaks in the local community.

An Approach to Intraoperatively Identify the Coronal Plane Deformities of the Distal Tibia When Treating Tibial Fractures with Intramedullary Nail Fixation: a Retrospective Study.

ObjectiveTo develop a new approach to intraoperatively identify the presence of coronal plane deformities (both valgus and varus) when treating tibial fractures with closed reduction and intramedullary nail fixation.MethodsA retrospective analysis was conducted by enrolling 33 consecutive patients with tibial fractures who received closed reduction and intramedullary nail fixation from January 2018 to January 2019 at our trauma center. Out of the 33 patients, 23 were males and 10 were females and the average age was 41 years (ranging 22 to 69 years of age). Standard anteroposterior and lateral preoperative radiographs were routinely performed. After intraoperatively inserting the tibial intramedullary nail through the standard entry point, the parallel relationship between the distal horizontal interlocking screw and the tibiotalar joint surface on the anteroposterior fluoroscopy was used to determine the occurrence of valgus or varus deformities of the distal tibial fragment. Radiographic and clinical outcomes were analyzed using the average interval from injury to surgery, the lateral distal tibial angle (LDTA) of the unaffected and affected sides, complications and the Olerud–Molander ankle score.ResultsAll 33 patients were postoperatively followed for 13 to 25 months (mean 18.7 months). The fractures achieved bone union at an average of 4.3 months (ranging from 3 to 6 months). The total complication rate was 60.6% (20 cases), including four cases that showed deep vein thrombosis, one case showing an infection and delayed union and 15 cases showing slight to moderate anterior knee pain. The postoperative LDTA of the unaffected side measured 87.3° to 89.6 ° (average 88.7° ± 0.8°), and the LDTA of the affected side was 87.5° to 90.4° (average 88.9° ± 1.1°). There was no significant difference between the unaffected and affected sides (t = −1.865, P = 0.068). The intraoperative measurement indicated six cases of valgus angulation and three cases of varus angulation deformities, and all deformities were corrected during surgery. According to the Olerud–Molander ankle score, clinical outcomes demonstrated 22 excellent cases, eight good cases, two fair cases, and one poor case 12 months after surgery.ConclusionThe parallel relationship between the distal horizontal interlocking screw and tibiotalar joint surface on intraoperative anteroposterior films were able to determine the onset of valgus or varus angulations of the distal tibial fragment in the fracture zone after the tibial intramedullary nail was inserted through the standard entry point.

Structures at Risk in the Arthroscopic Brostrom-Gould Procedure: A Cadaver Study

Category:Ankle, Arthroscopy, Basic Sciences/Biologics, SportsIntroduction/Purpose:The Broström Gould procedure is the gold standard for repair of lateral ankle ligament injury and ankle instability. This procedure has demonstrated excellent short- and long-term outcomes in the orthopaedic literature. Arthroscopic Broström Gould techniques have become increasingly popular among some foot and ankle orthopaedic surgeons. Typically, this technique requires standard medial and lateral portals along with an accessory lateral working portal. The exact location of this portal is variable within the available described surgical techniques. The objective of this cadaveric study is to establish a standard entry point for and to assess the safety of the accessory lateral portal with respect to nearby anatomical structures.Methods:Ten fresh-frozen below-knee cadaver specimens were used. The location of the accessory portal was created 1.5 cm anterior to the distal tip of the fibula. A small vertical incision was made at this point, followed by insertion of a Kirschner wire into the joint. The wire was then gently impacted into the fibula. Superficial dissection was subsequently carried out around the entry point to identify the peroneal tendons, superficial peroneal nerve branches, and sural nerve branches. Structures were marked with colored push pins, and distance was measured between the nearest edge of the Kirschner wire and each of the three anatomic structures listed. Any instances of structural contact or damage were documented.Results:The average distance from the Kirschner wire to the peroneal tendon was 16.1 (±4.41) mm. The average distance from the wire to the superficial peroneal nerve and sural nerve was 13.11 (±6.79) mm and 12.33 (±4.08) mm, respectively. There were no instances of injury to any of the studied structures. However, there was a notable amount of variability in the proximity of structures in question for each cadaver. A branch of the superficial peroneal nerve was measured as close as 2 mm and as far as 24 mm in separate cadaver specimens.Conclusion:Arthroscopic Broström Gould procedures are a safe and effective method for lateral ankle ligamentous repair but are not without risk. Accessory lateral portal placement is relatively safe but should be meticulously executed to avoid damage to nearby anatomical structures.

Anatomical structures at risk in the arthroscopic Broström-Gould procedure: A cadaver study

BackgroundThe Broström Gould procedure is the gold standard for repair of lateral ankle ligament injury and ankle instability. This procedure has demonstrated excellent short- and long-term outcomes in the orthopedic literature. Arthroscopic Broström Gould techniques have become increasingly popular among some foot and ankle orthopedic surgeons. Typically, this technique requires standard anteromedial and anterolateral portals along with an accessory lateral working portal. The exact location of this portal is variable within the available described surgical techniques. The objective of this cadaveric study is to establish a standard entry point for and to assess the safety of the accessory lateral portal with respect to nearby anatomical structures. MethodsTen fresh-frozen below-knee cadaver specimens were used. The location of the accessory lateral portal was created 1.5 cm anterior to the distal tip of the fibula. A small vertical incision was made at this point, followed by insertion of a Kirschner wire into the joint. The wire was then gently impacted into the fibula. Superficial dissection was subsequently carried out around the entry point to identify the peroneal tendons, superficial peroneal nerve branches, and sural nerve branches. Structures were marked with colored push pins, and distance was measured between the nearest edge of the Kirschner wire and each of the three anatomic structures listed. Any instances of structural contact or damage were documented. ResultsThe average distance from the Kirschner wire to the peroneal tendon was 16.1 (±4.41) mm. The average distance from the wire to the superficial peroneal nerve and sural nerve was 13.11 (±6.79) mm and 12.33 (±4.08) mm, respectively. There were no instances of injury to any of the studied structures. However, there was a notable amount of variability in the proximity of structures in question for each cadaver. A branch of the superficial peroneal nerve was measured as close as 2 mm and as far as 24 mm in separate cadaver specimens. ConclusionArthroscopic Broström Gould procedures are a safe and effective method for lateral ankle ligamentous repair but are not without risk. Accessory lateral portal placement is relatively safe but should be meticulously executed to avoid damage to nearby anatomical structures.

Hydrodisplacement of sural nerve for safety and efficacy of endovenous thermal ablation for small saphenous vein incompetence.

Background Endovenous radio frequency ablation for small saphenous vein incompetence by and large appears to be superior and safer than conventional open surgery. Small saphenous vein ablation from approximately mid-calf to the point proximally where the small saphenous vein dives into the popliteal fossa is considered to be safe, as the sural nerve is in most cases separated from this segment of the small saphenous vein by the deep fascia. The outcome of the distal incompetent small saphenous vein remains unclear. Efficacy of the endovenous radio frequency ablation can be enhanced by increasing the length of the ablatable small saphenous vein segment. Methodology To optimise endovenous radio frequency ablation outcome, the distal small saphenous vein may be made amenable to ablation if safety of the sural nerve can be assured. The sural nerve was successfully located using duplex ultrasound in 100% of our cohort in this study. The standard entry point for venous access was just above the lateral malleolus. After introduction of the introducer sheath, the radio frequency catheter was advanced proximally; the sural nerve was displaced from the small saphenous vein by approximately 1 cm with the administration of tumescent anaesthesia ( hydrodisplacement). A total of 118 patients underwent extended endovenous radio frequency ablation of 124 incompetent small saphenous vein trunks using the method described. Results Successful extended ablation of the small saphenous vein was achieved in 100% of cases and it was confirmed by duplex scanning at one and six weeks. Two neurological events were recorded during the study: 1. One patient with temporary foot drop lasting for less than 6 h with complete recovery. 2. A second patient with a sural nerve sensory deficit reported by the patient at day 2-3, which remains current at six weeks. Conclusions Extended endovenous radio frequency ablation of the small saphenous vein to optimise length of the ablatable vein segment is feasible with careful identification and hydrodisplacement of the sural nerve. This method is shown to be associated with fewer neurological complications than other methods reported in the literature.

Is there a bone-nail specific entry point? Automated fit quantification of tibial nail designs during the insertion for six different nail entry points

Intramedullary nailing is the standard fixation method for displaced diaphyseal fractures of tibia. Selection of the correct nail insertion point is important for axial alignment of bone fragments and to avoid iatrogenic fractures. However, the standard entry point (SEP) may not always optimise the bone-nail fit due to geometric variations of bones. This study aimed to investigate the optimal entry for a given bone-nail pair using the fit quantification software tool previously developed by the authors.The misfit was quantified for 20 bones with two nail designs (ETN and ETN-Proximal Bend) related to the SEP and 5 entry points which were 5 mm and 10 mm away from the SEP.The SEP was the optimal entry point for 50% of the bones used. For the remaining bones, the optimal entry point was located 5 mm away from the SEP, which improved the overall fit by 40% on average. However, entry points 10 mm away from the SEP doubled the misfit.The optimised bone-nail fit can be achieved through the SEP and within the range of a 5 mm radius, except posteriorly. The study results suggest that the optimal entry point should be selected by considering the fit during insertion and not only at the final position.

Pedicle screw insertion angle and pullout strength: comparison of 2 proposed strategies

Minimally invasive pedicle screws inserted vertically (that is, dorsoventrally) through the pedicle, as opposed to the more common coaxial technique, offer potential advantages by minimizing soft-tissue stripping during screw placement. The screws are designed for insertion through a medial starting point with vertical trajectory through the pedicle and into the vertebral body. As such, no lateral dissection beyond the insertion point is necessary. However, the effects of this insertion technique on the screw biomechanical performance over a short- and long-term are unknown. The authors investigated the pullout strength and stiffness of these screws, with or without fatigue cycling, compared with comparably sized, traditional screws placed by coaxial technique. Twenty-one lumbar vertebrae (L-3, L-4, and L-5) were tested. Each pedicle of each vertebra was instrumented with either a traditional, coaxial pedicle screw (Group A), placed through a standard starting point, or a vertically oriented, alternative-design screw (Group B), with a medial starting point and vertical trajectory. The specimens were divided into 2 groups for testing. One group was tested for direct pullout (10 specimens) while the other was subject to pullout after tangential (toggle) cyclic loading (11 specimens). The screws were cycled in displacement control (± 5 mm producing ~ 4-Nm moment) at a rate of 3 Hz for 5000 cycles. Pullout tests were performed at a rate of 1 mm/minute. Two-way ANOVA showed that Group B screws with a medial starting point (2541 ± 1090 N for cycled vs 2135 ± 1323 N for noncycled) had significantly higher pullout loads than Group A screws with a standard entry point (1585 ± 766 N for cycled vs 1417 ± 812 N noncycled) (p = 0.001). There was no significant effect of cycling or screw insertion type on pullout stiffness. Tangential stiffness of the Group B screws was significantly less than that of the Group A screws (p = 0.001). The stiffness of both screws in the toe region was significantly affected by cycling (p = 0.001). The use of Group B screws inserted through a medial starting point showed greater pullout load than a Group A screw inserted through a standard starting point. The greater pullout strength in Group B screws may be due to screw thread design and increased cortical bone purchase at the medial starting point. Nevertheless, anatomical considerations of the medial starting point, that is, pedicle or lateral vertebral body cortex breach, may limit its application. The medial starting point of the Group B screw was frequently in the facet at the L-3 and L-4 pedicle entry points, which may have clinical importance.

The Need for Partner Consent Is a Main Reason for Opting Out of Routine HIV Testing for Prevention of Mother-to-Child Transmission in a Rural Ugandan Hospital

Across Africa in 2005 100000 women) can be expected to be infected with HIV. Thus as routine HCT becomes the standard entry point to PMTCT programs understanding the reasons why some women decline the service is increasingly important. (excerpt)

Intramedullary Fracture Reduction of Long Bone Under Visual Control: Experimental Results of an Endoscopic Technique

Abstract In controlling the closed reduction of a shaft fracture of long bone during an operation, intraoperative radiography is essential. The amount of imaging needed depends on the patient, the fracture, and the surgeon. This article documents our first experimental results of closed fracture reduction performed under direct visual control with the endoscopic technique of intramedullary bone endoscopy (IBE), which eliminates the need for fluoroscopy. On 3 human tibial cadaveric bones, an artificial shaft fracture was set. The lower leg was fixed on a brace, and the endoscope was inserted at the standard entry point for intramedullary nailing. The endoscope was gently pushed distally to prepare the medullary canal under visual control with the use of endoscopic instruments. At the level of fracture, surgeons achieved a closed reduction by “looking around” for the distal part of the fracture by using the stiff endoscope similarly to a “joystick.” Thus, the proximal fragment was automatically guided into the correct position, and the fracture was reduced. The endoscopic tool was pushed down the medullary canal into the distal fragment in the way that a guidewire would be placed. Through this technique, it has been possible in all patients to reduce fractures under visual control. Fluoroscopy can be eliminated in these cases.

Piriform and trochanteric fossae. A drawing mismatch or a terminology error? A review

The current literature indicates that the standard starting point for intramedullary nailing is the piriform fossa. The accuracy of the entry point for anterograde femoral intramedullary nailing between published texts and relevant illustrations was recorded. The piriform fossa is the site of insertion of the piriform tendon and represents a small, shallow depression located on the tip of the greater trochanter. The trochanteric fossa is a deep depression on the inner surface of the greater trochanter, and in the vast majority of the published data is indicated incorrectly as "piriform fossa". As a result of either a recurrent drawing mismatch or a terminology error, the correct entry point for anterograde femoral intramedullary nailing is confusing and should be indicated in the current literature. The trochanteric fossa appears to be the standard entry point that most surgeons recommend.