Anterior Posterior Screw Research Articles

Posterior-anterior versus anterior-posterior screws for posterior malleolar fractures: A meta-analysis.

The incidence of posterior malleolus fractures in ankle fractures ranges from 7% to 44%. Studies have indicated a poorer prognosis for ankle joint function when a posterior malleolar fracture is present, underscoring the significance of active intervention for optimal postoperative ankle function recovery. Hence, the selection of treatment for such fractures holds particular importance. Screw fixation is a key treatment for posterior malleolus fractures (PMFs) or Haraguchi Type 1 fractures involving less than 25% of the distal tibia's articular surface. However, the optimal screw placement direction - anteroposterior (AP) or posterior-anterior (PA) - remains debated. This meta-analysis aims to compare these two approaches for treating posterior ankle fractures, focusing on the efficacy of PA fixation. We searched the Cochrane Library, EMBASE, PubMed, SinoMed, and Web of Science databases from their inception to October 20, 2022. Methodological quality was assessed using the Cochrane Collaboration's tool for assessing bias risk in randomized controlled trials (RCTs). Stata MP17 software was used to compare the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, full weight-bearing time, and fracture healing time at the last follow-up between the two fixation methods. A total of 403 patients with posterior malleolar fractures from six RCTs met the inclusion criteria. The meta-analysis revealed a higher AOFAS score at the last follow-up for PA placement compared to AP placement [SMD = 0.512, 95% CI (0.244 to 0.780), z= 3.74, P< 0.001]. Postoperative full weight-bearing time and fracture healing time did not show statistically significant differences between the two groups. PA fixation demonstrated a superior AOFAS score compared to AP fixation for posterior malleolar fractures. PA screw placement offers advantages in restoring ankle joint stability and enhancing joint function recovery post-surgery.

Biomechanical testing of a computationally optimized far cortical locking plate versus traditional implants for distal femur fracture repair

BackgroundThis study experimentally validated a computationally optimized screw number and screw distribution far cortical locking distal femur fracture plate and compared the results to traditional implants. Methods24 artificial femurs were osteotomized with a 10 mm fracture gap 60 mm proximal to the intercondylar notch. Three fixation constructs were used. (i) Standard locking plates secured with three far cortical locking screws inserted according to a previously optimized distribution in the femur shaft (n = 8). (ii) Standard locking plates secured with four standard locking screws inserted in alternating plate holes in the femur shaft (n = 8). (iii) Retrograde intramedullary nail secured proximally with one anterior-posterior screw and distally with two oblique screws (n = 8). Axial hip forces (700 and 2800 N) were applied while measuring axial interfragmentary motion, shear interfragmentary motion, and overall stiffness. FindingsExperimental far cortical locking plate results compared well to published computational findings. Far cortical locking femurs contained the highest axial motion within the potential ideal range of 0.2–1 mm and a sheer-to-axial motion ratio < 1.6 at toe-touch weight-bearing (700 N). At full weight-bearing (2800 N), Standard locking-plated femurs had the only axial motion within 0.2–1 mm but had an excess shear-to-axial motion ratio. Nail-implanted femurs underperformed at both forces. InterpretationFor toe-touch weight-bearing, the far cortical locking construct provided optimal biomechanics to allow moderate motion, which has been suggested to encourage early callus formation. Conversely, at full weight-bearing, the standard locking construct offered the biomechanical advantage on fracture motion.

Comparative biomechanical analysis of tibial posterior slope in medial open wedge high tibial osteotomy vs. distal tuberosity osteotomy with and without anterior-posterior screw: a study using porcine tibia.

Biomechanical evaluations were conducted on thirty porcine tibias using MOWHTO and DTO, with and without an anterior-posterior (AP) screw. To investigate PTS changes, cyclic testing was carried out for MOWHTO and DTO. Displacement along the mechanical axis during cycles 10th, 100th, 500th, 1000th, 1500th and 2000th, variations in anterior and posterior gaps after 2000 cycles and increased PTS after 2000 cycles, were compared across the three groups. The displacement was evaluated by repeated-measures analysis of variance (ANOVA), and changes in AG and PG and increased PTS were evaluated by one-way ANOVA. The sample size for α and β errors were <0.05 and <0.20, and the effect size was 0.60 for one-way ANOVA and 0.46 for repeated-measures ANOVA. There were no significant differences in displacement and anterior gap changes among the groups. A significant difference was observed in the posterior gap changes (P < 0.001) and increased PTS (P = 0.013) among the groups. Post hoc analysis indicated substantial disparities between MOWHTO and DTO without the AP screw (P = 0.035), as well as between MOWHTO and DTO with the AP screw (P = 0.021) concerning the increased PTS. After cyclic loading, MOWHTO exhibited a notably smaller PTS change than DTO regardless of the presence of an AP screw.

Study on the effect of self-made fracture positioning compression guide device for posterior malleolus fracture surgery: Medical prevention

To evaluate the effectiveness of a self-designed pressure-guided fracture positioning device, a prospective study was conducted in patients with posterior ankle fractures undergoing surgery using the device. Twenty-seven cases of ankle joint fracture with posterior malleolus fracture were treated by surgery. In the process of fixing posterior malleolus fracture, a self-designed fracture positioning compression guide device was used to fix posterior malleolus bone by anterior and posterior approaches. Postoperative CT images were used to assess the fixation position as well as length of the screw and the compression of the fracture. All patients had healed ankle fractures, and the anterior-posterior screws were fixed in the central area of the posterior malleolus. Posterior malleolus fragment displacement was <2 mm. The screw effectively secured the cortex beyond the length of the posterior malleolus cortex by no more than two threads. The good rate of ankle joint function was 85.16%. Compared to traditional surgical techniques, minimally invasive fixation using the self-designed positioning compression guide device has several advantages, including smaller trauma, faster postoperative recovery, and improved patient satisfaction. The device also provides the surgeon with greater control and precision during the surgical procedure, which can contribute to better surgical outcomes.

Fracture gap of the lateral malleolus via posterolateral approach: Improved visualization of the posterior malleolus fracture

The treatment of posterior malleolar fractures is a popular issue. Anatomic reduction of posterior malleolar fractures is critical for re-establishing the stability of the ankle mortise and ligamentous union after trauma. Inappropriate treatment ultimately leads to poorer functional outcomes and lower quality of life. Open reduction and internal fixation through a posterolateral approach are preferred over indirect reduction and anterior-posterior screw fixation. Although the posterolateral approach, which is more common and direct, provides good exposure to the fracture site, it has some limitations. In this report, we describe the posterolateral approach through the lateral ankle fracture gap for the treatment of posterior ankle fractures. Moreover, we discuss the indications, benefits, and limitations of this approach.

A COMPARATIVE STUDY OF ANTERO-POSTERIOR SCREW VERSUS POSTERO-ANTERIOR SCREW FOR POSTERIOR MALLEOLUS FRACTURE

ntroduction: Optimal treatment of ankle fractures with posterior malleolus fragment is controversial. Posterior malleolus is signicant stabilizer preventing posterior subluxation of ankle. Posterior malleolus fracture have generally been neglected because of these fragment is considered to be reduce spontaneously after open reduction of the lateral malleolus by ligamentotaxis by posterior-inferior tibiobular ligament. Fixation of this fragment is important in the role of ankle mechanics. WeObjectives: compare in this study better surgical &amp; functional outcome for this posterior malleolus fracture xation by AP SCREW and PA SCREW Methods: We prospectively evaluated 30 patients (15 patients for AP screw xation and 15 patients for PA screw xation who underwent for xation by anterior posterior screw by percutaneous method and posterior lateral approach for posterior anterior screw xation. We assigned alternating patient who received AP SCREW xation VS PA SCREW xation based on order in which they presented to our institution.We use American Orthopedics foot and ankle society (AOFAS) score, range of motion of ankle and X-Ray nding. The mean Follow up was 15 Months(Range 12-20 Months). Full union without any loss of reduction was obtained in 27 out of 30 patients. As anteriorResult &amp; Discussion: posterior screw is a blind procedure, the risk of injury to anterior tibial artery &amp; nerve, purchase of screws distal threads for fragment is debatable. In posterior plating better visualization of fragment and anatomy will help in better xation of posterio malleoi fragment. Assessment of treatment outcome using the AOFAS demonstrated signicant high score of 97.4 in group with posterior antero screw xation with posterior lateral approach compare to score of 80 in group anterior posterior screw xation. In comparison to the anterior-posterior screwConclusions: xation,open reduction and xation of the, posterolateral key fragment of the ankle using posterolateral approach via Posterior anterior screw resulted in a more accurate fracture reduction outcome 12 months after surgery.

Defining an Anatomic and Radiographic Safe Zone for Posterior Malleolar Ankle Hardware Fixation

Category:Ankle; TraumaIntroduction/Purpose:There is a lack of consensus regarding optimal management of Posterior Malleolar Fractures (PMFs). Indirect reduction and fixation with posterior-anterior (PA) screw shows promise of avoiding the risks associated with direct reduction or indirect anterior to posterior (AP) approaches. Some authors have raised concerns about potential risk to nearby structures with PA technique, including hardware prominence into the syndesmosis. This study highlights the use of a posteromedial vertical syndesmotic line as a fluoroscopic landmark, helping surgeons avoid intra-syndesmotic placement.Methods:Indirect PA screw placement was completed on ten cadaveric specimens, followed by fluoroscopy in mortise and lateral views. Dissection was performed to assess screw placement relative to the posteromedial border of the syndesmosis. The posterior border of the syndesmosis was marked with a radiopaque wire. Repeat imaging was completed to validate the fluoroscopic posteromedial vertical syndesmotic line is representative of the posteromedial border of the tibial incisura.Results:On dissection, 9 of 10 cadavers had accurate screw placement with no penetration into the syndesmosis (Figure 1, bottom left & bottom right). Corresponding imaging showed the screw head to be medial to the marker on mortise view. For the specimen with penetration into the syndesmosis, imaging confirmed that the screw head was lateral to the marker on mortise views (Figure 1, top center & top right). The radiopaque marker correlated with the posteromedial vertical syndesmotic line for all specimens when comparing anatomic to radiographic findings. A radiographic safe zone is defined for the PA screw 12 mm medial to the vertical syndesmotic line to ensure no iatrogenic injury to the FHL tendon.Conclusion:This study demonstrated that the posterior incisura tibialis fluoroscopic landmark is unambiguous in localizing the posterior syndesmotic border (Figure 1, top left) and that screws medial to this line are safely out of the syndesmosis, while screws placed lateral are either in or at risk of intra-syndesmotic placement. A safe zone is defined for screw placement.

Comparison of the efficacy of posterior-anterior screws, anterior-posterior screws and a posterior-anterior plate in the fixation of posterior malleolar fractures with a fragment size of\u2009\u2265\u200915 and\u2009

BackgroundDifferent fixation methods have been used to treat posterior malleolar fractures (PMFs), but the clinical efficacy of different fixation methods in the treatment of PMF with different fragmentation has rarely been reported. The purpose of this study was to investigate the efficacy of posterior-anterior (PA), anterior-posterior (AP) screws and PA plate in the fixation of PMFs with a fragment size of ≥15 and < 15%.MethodsThis is a retrospective study of the clinical data of 243 patients with a unilateral ankle fracture involving the posterior malleolar ankle fracture. All patients were divided into two groups based on their fragment size, ≥15% (n = 136) and < 15% (n = 107). After reduction of PMF under direct vision via a posterolateral approach, posterior-anterior (PA), anterior-posterior (AP) screws and PA plate were used for fixation of PMF in the two groups. Briefly, for fixation of PMF with PA screw, two to three 3.5-mm (Depuy Synthes, Switzerland) cannulated screws were placed from the posterior to anterior direction; for fixation with PA plate, a 3.5-mm reconstruction plate (Depuy Synthes, Switzerland) was placed from the posterior to anterior direction, and for fixation of PMF with an AP screw, two to three 3.5-mm screws were placed from the anterior to posterior direction. All patients were followed up at 1, 3, 6, and 12 months after surgery and thereafter at 6-month intervals. The primary outcomes were AOFAS and ROM, which were recorded at the final follow-up.ResultsThe average follow-up time for all patients was 18.9 months (range 12–36 months), and all fractures healed. In fragment size ≥15% group, the average AOFAS score of patients treated with PA, AP screws and posterior plate were 91.5, 91.8, and 90.8, respectively, and the average limited ankle-dorsiflexion ROM was 5.0 °, 5.4 ° and 5.6°, respectively, at the last follow-up, there was no significant difference between the three fixation methods in terms of AOFAS scores and ankle ROM (P > 0.05). In fragment size < 15% group, the average AOFAS score of patients treated with PA, AP screws and posterior plate were 92.3, 91.9, and 84.1, respectively, the average limited ankle-dorsiflexion ROM were 5.1 °, 4.7 °, and 6.3 °, respectively, at the last follow-up. There were statistically significant differences in AOFAS scores and ankle ROM between posterior plate fixation and PA, AP screw fixation (P < 0.05); while no significant difference was found between PA and AP screw fixation (P > 0.05).ConclusionFor PMFs with fragment size ≥15%, there was no significant difference in the outcomes between the three fixation methods. For PMF with fragmentation < 15%, the PA and AP screws both provided good fixation.

Anatomic structures at risk in anteroposterior screw fixation of posterior malleolar fractures: A cadaver study

IntroductionPercutaneous anterior-posterior (AP) screw is an option for posterior malleolus fracture fixation when the fracture fragment can be reduced indirectly by the mean of ligamentotaxis. However, anterior anatomic structures could be injured during screw placement. Materials and methodsEleven below-knee cadavers were employed for the placement of AP screws in an attempt of fixing assumed Haraguchi Type-I posterior malleolar fractures. Three entry points were selected as medial to the anterior tibial tendon (ATT), lateral to the ATT, and lateral to the extensor digitorum longus (EDL). Three AP screws were placed under guidance of fluoroscopy. After dissection, measurements were made (mm) from each screw to nearby structures. Distances were calculated and damage to structures was documented. ResultsMean, minimum, and maximum distances from the medial screw to the greater saphenous vein, TA, EHL, anterior tibial artery (ATA), and deep peroneal nerve (DPN), were 18.1 (12–25) mm, 2.0 (0–5) mm, 13.6 (9–20) mm, 16.6 (9–25) mm, and 20.1 (12–27) mm. From the middle screw to the ATA, DPN, TA, EHL, and EDL, were 1.2 (0–3) mm, 4.9 (3–9) mm, 3.8 (1–7) mm, 0.4 (0–2) mm, and 13.6 (10–18) mm. From the lateral screw to the superficial peroneal nerve (SPN), EDL, DPN, and ATA, were 10.8 (0–16) mm, 1.2 (0–4) mm, 15.9 (11–25) mm, 19 (15–27) mm. The SPN was found partially cut by the lateral screw on 1 specimen. ConclusionsLateral and middle percutaneous AP screw placement put certain anatomic structures at-risk of injury. Medial screw placement did not result in appreciable damage to adjacent structures. Entry point of AP screws should be selected with respect to posterior malleolar fracture and anatomic structures. Level of evidenceIV.

Comparison of lag screw fixation on posterior malleolar fractures in different directions and screw-related complication

Objective To compare the effects of indirect reduction, percutaneous anterior posterior screw and direct reduction, posterior anterior screw in the treatment of posterior malleolus fracture. Methods A retrospective analysis was made on 58 patients with posterior malleolus fracture treated by cannulated screw fixation from January 2013 to December 2017 in the Department of Orthopedics, Affiliated Hospital of Guangdong Medical University.They were divided into anterior and posterior screw group (26 cases) and posterior and anterior screw group (32 cases) according to different treatment methods.The incidence of poor screw position and other complications were compared between the two groups.Health status and ankle function at the last follow-up were compared between the two groups. Results The incidence of screw malposition in the anterior and posterior screw fixation group was 23.08%(6/26), which was significantly higher than that in the posterior screw fixation group was 3.85%(1/32). The difference between the two groups has statistically significant (χ2=5.381, P=0.020); there was no significant difference in other complications such as infection, traumatic arthritis, bone nonunion (all P>0.05). At the last follow-up, the OMA scores of AP group were (80.70±8.16)and PA group were(75.23±9.33), There were significant differences between the two scores(t=2.240, P=0.029), the AOFAS scores of AP group were (80.57±7.25) and PA group were(75.38±10.19), There were significant differences between the two scores(t=2.110, P=0.039). Conclusion The Indirect reduction and percutaneous anterior and posterior screw treatment have a high incidence of malposition of the screw, which has an impact on ankle function.Direct reduction and posterior and anterior screw fixation can significantly reduce the incidence of malposition of the screw and obtain better functional results. Key words: Posterior malleolus fracture; Indirect reduction; Poor screw position; Ankle function

Entry Point Safe Zone for Anteroposterior Screws in Posterior Malleolus Fracture Fixation: A Cadaver Study

Category:Ankle, Basic Sciences/Biologics, TraumaIntroduction/Purpose:Percutaneous anterior-posterior (AP) screw is an option for posterior malleolus fracture fixation when the fracture fragment can be reduced indirectly by the means of ligamentotaxis. However, anterior anatomic structures could be injured during screw placement. We assessed this risk in cadavers.Methods:Eleven below-knee cadavers were employed for the placement of AP screws in an attempt of fixing assumed Haraguchi Type-I posterior malleolar fractures. Three entry point, medial, middle, and lateral, were selected as medial to the tendon of tibialis anterior (TAT), lateral to the TAT, and lateral to the extensor digitorum longus (EDL). On each cadaver, three AP screws were placed under the guidance of fluoroscopy. After dissection, measurements were made (mm) from each screw to nearby structures. Mean, minimum, maximum distances, and 95% confidence intervals were calculated. Instances of damage to the structures were recorded.Results:Mean, minimum, and maximum distances from the medial screw to the saphenous vein, TA, EHL, anterior tibial artery (ATA), and deep peroneal nerve (DPN), were 18.1 (12-25) mm, 2.0 (0-5) mm, 13.6 (9-20) mm, 16.6 (9-25) mm, and 20.1 (12-27) mm. From the middle screw to the ATA, DPN, TA, EHL, and EDL, were 1.2 (0-3) mm, 4.9 (3-9) mm, 3.8 (1-7) mm, 0.4 (0-2) mm, and 13.6 (10-18) mm. From the lateral screw to the superficial peroneal nerve (SPN), EDL, DPN, and ATA, were 10.8 (0-16) mm, 1.2 (0-4) mm, 15.9 (11-25) mm, 19 (15-27) mm. The SPN was found partially cut by the lateral screw on 1 specimen. The middle screws were adjacent to the ATA and DPN without damaging to them.Conclusion:Lateral and middle percutaneous AP screw placement put certain anatomic structures at-risk of injury. Medial screw placement did not result in appreciable damage to adjacent structures. Entry point of AP screws should be selected with respect to posterior malleolar fracture and anatomic structures. Meticulous dissection should be performed when placing anteroposterior screws.

A Comparison of the Compressive Strength of Various Distal Locking Screw Options in the Treatment of Tibia Fractures with Intramedullary Nails

Treatment of distal metaphyseal tibia fractures is often challenging. Newer tibial intramedullary (IM) nails are designed with a wider variety of distal locking options to offer greater stability in treating these fractures. In this study we attempted to determine the most biomechanically stable number and configuration of distal locking screws when treating distal metaphyseal tibia fractures with IM nails. A transverse osteotomy was created 4 cm from the tibial plafond in identical composite saw bones models (Type 43A fracture) as well as in human cadaveric bones. Each specimen was nailed using a tibial nail (Stryker T2). Distal locking was performed in one of the three configurations: (a) Group I: two screws in the medial lateral (ML) direction; (b) Group II: one ML screw and one screw in the anterior posterior (AP) direction; (c) Group 111: two ML screws and one AP screw. The specimens were then mounted onto a uniaxial material testing machine (Instron) and tested in compression. Our results showed that there was no statistical difference in the load-carrying capacity of Group 1 and Group II. This suggests that the treating surgeon can choose either of these two configurations depending on the wound or other considerations without sacrificing the compressive load-carrying capacity of the IM nail fixation. The load-carrying capacity of the Group III samples with these locking screws was higher than those of Group I & II, although this difference was not statistically significant. This work is being continued to compare the load-carrying capacity of the bone samples with the cortical thickness of bone. We also plan to examine the relationship between the load-carrying capacity of these surgical constructs with the bone mineral density of the metaphysis of these tibial specimens.

Radiographic analysis of femoral interference screw placement during ACL reconstruction: Endoscopic versus open technique

Fifty patients with anterior cruciate ligament reconstruction using a bone-patellar tendon-bone autograft performed by two techniques were evaluated roentgenographically to compare the position of the femoral interference screws. Group I consisted of 25 patients in whom the screw was placed using a distal lateral femoral incision (the two-incision technique). Group II patients underwent arthroscopically assisted intraarticular placement of the screw. These patients were then evaluated with anterior-posterior (AP) and lateral roentgenograms. We observed that the AP and lateral screw angles were significantly different with the two techniques. In addition, the endoscopic placement of the femoral screw had an associated divergence of the screw relative to the bone plug in nine of 25 patients compared with zero of 25 in the open group. In conclusion, radiographic differences do exist between femoral interference screws placed for fixation of an ACL graft using the open approach and those placed endoscopically. Although the clinical significance of these differences is not known, we raise the question of greater divergence in femoral interference screw placement with the newer intraarticular femoral interference screw placement techniques.