跟骨内外侧经皮置针安全区解剖学研究

目的 划定国人跟骨内、外侧外固定针进针位置解剖学相对安全区.方法 解剖14具正常成年人足踝部标本.于跟骨内侧取跟骨最内下后点为A点,内踝最下点为B点,足舟骨结节为C点.解剖出跟骨内侧神经、足底外侧神经最后分支、足底外侧神经、足底内侧神经、胫后动脉、足底外侧动脉和足底内侧动脉.根据各结构行经AB、AC线的位置,确定跟骨内侧的相对安全区;于跟骨外侧取跟骨最外下后点为D点,外踝最下点为E点,解剖出跟骨外侧神经、腓肠神经、小隐静脉主干,同理确定跟骨外侧的相对安全区.结果 跟骨内侧神经、足底外侧神经最后分支、足底外侧神经、足底内侧神经、胫后动脉分别行经AB线后下22%、50%、56%、64%及58%处,跟骨内侧神经、足底外侧神经最后分支、足底外侧神经、足底内侧神经、足底外侧动脉、足底内侧动脉分别行经AC线后下14%、39%、49%、63%、41%及57%处.跟骨外侧神经、腓肠神经、小隐静脉分别行经DE线后下 19%、65%及61%处.结论 在跟骨内侧,AB线后1/2、AC线后1/3所在圆形区域为经皮置针相对安全区.在跟骨外侧,经DE线中点垂线后方的跟骨为经皮穿针相对安全区.     

The vascularization of the os calcaneum and the clinical consequences.

This study was conducted to analyze extraosseous and intraosseous vascularization of the os calcaneum and to elucidate possible clinical manifestations. The arteries of 13 lower leg and foot specimens of human cadavers were injected with a polymer and subjected to maceration or were embedded in plastic. The examination revealed that 45% of the bone is vascularized via medial arteries and 45% via lateral arteries, whereas the remaining 10% is supplied by the sinus tarsi artery. From the medial side, two or three vessels branch off the posterior tibial artery, penetrate the calcaneus below the sustentaculum, and supply the medial part of the posterior joint. The lateral calcaneal artery normally is a branch from the posterior tibial artery. In two of 13 specimens, this lateral supply comes from the peroneal artery. The medial and lateral intraosseous arterial supply for the calcaneus is equal. Inside the bone there is a water-shed zone where the medial and lateral arterial supply meet in the midline. Only 10% of the blood flow is supplied by vessels in the sinus tarsi. Clinically, interruption of the lateral calcaneal artery during the conventional lateral surgical approach for a calcaneus fracture may result in ischemic bone necrosis. The lateral calcaneal artery could supply a local microvascular flap to cover soft tissue defects of the heel. A compartment syndrome after a calcaneus fracture may be caused by bleeding from the medial calcaneal arteries into the quadratus plantae compartment.     

Percutaneous pin placement in the medial calcaneus: is anywhere safe?

OBJECTIVE: To redefine the medial calcaneal anatomic safe zone for pin placement with respect to reproducible palpable landmarks. DESIGN: Anatomic study. SETTING: Medical school anatomy laboratory. INTERVENTIONS: Thirty-three fresh-frozen adult cadaveric feet were used. Three palpable anatomic landmarks were identified on each ankle and labeled as Point A (posteroinferior medial calcaneus), Point B (inferior medial malleolus), and Point C (navicular tuberosity). The medial neurovascular bundle was carefully dissected, and the medial calcaneal nerve, the most posterior branch of the lateral plantar nerve, the lateral plantar nerve, the medial plantar nerve, and the posterior tibial artery were identified. These structures were recorded at the point at which they transected a line from Point A to B and from Point A to C. Based on the findings of the first thirty-three feet, two pins were placed percutaneously into the medial calcaneus of ten additional feet. Pin 1 was placed one half the distance from Point A to B. Pin 2 was placed one third the distance from Point A to C. The neurovascular structures were then dissected and identified in relation to the pin position. RESULTS: The medial calcaneal, most posterior branch of the lateral plantar, and lateral plantar nerves are at significant risk for abutting the pins or being directly injured at the margins of these relative safe zones. CONCLUSION: The medial calcaneus provides a small window for safe percutaneous pin placement. Posterior to the halfway point from Point A to B and posterior to the one-third mark from Point A to C remain the relatively safest regions; a more posterior placement in the safe zone is safest. Careful blunt dissection and the use of cannulas may help to avoid neurovascular injury.     

Neurovascular risk of bicortical tibial drilling for screw and spiked washer fixation of soft-tissue anterior cruciate ligament graft

Purpose: As the use of soft-tissue anterior cruciate ligament (ACL) grafts, including hamstring grafts, has become more prominent and the benefits of aggressive rehabilitation have become clear, maximizing fixation with screw and spiked washers is important. Bicortical fixation may be superior. We were concerned about potential neurovascular risks and designed this study to define the posterior neurovasculature structures at risk when drilling for bicortical tibial screw fixation during ACL reconstruction. Type of Study: Consecutive sample. Methods: We placed the tibial tunnel arthroscopically in 10 cadaveric knees using a standard tibial drill guide. Accurate tibial tunnel position was documented in each knee by lateral radiograph. A 4.5-mm bicortical drill hole was placed perpendicular to the tibial surface 1 cm distal to the tibial tunnel. The distances from the posterior tibial drill exit point to nearby neurovascular structures were measured with a caliper. Results: The closest structure to the exit point was the bifurcation of the popliteal artery/vein (11.4 ± 0.6 mm; range, 8.4 to 14.0 mm). The next closest was the anterior tibial vein (11.7 ± 1.6 mm; range, 3.5 to 22.8 mm). The closest any individual hole came to a neurovascular structure was 3.5 mm from the anterior tibial vein. Conclusions: Bicortical drilling for fixation of soft tissue grafts appears reasonably safe. The structures at greatest risk for injury are the bifurcation of the popliteal artery/vein and the anterior tibial vein.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 3 (March), 2001: pp 244–247     

Assessment of medial and lateral neurovascular structures after percutaneous posterior calcaneal displacement osteotomy: a cadaver study

A prospective investigation of the effects on the medial and lateral neurovascular structures of the rearfoot after percutaneous posterior calcaneal displacement osteotomy was performed using 20 below the knee fresh frozen cadaver specimens. This anatomic study aimed to examine the medial and lateral neurovascular structures to determine whether they were jeopardized during execution of the osteotomy. After completion of the osteotomy, the medial plantar, lateral plantar, medial calcaneal, sural, and posterior tibial neurovascular structures, along with their respective branches, were inspected for iatrogenic injury. Our findings demonstrated that the percutaneous, subperiosteal osteotomy minimized trauma to the local soft tissue envelope and protected the adjacent neurovascular structures. Because no iatrogenic injury was observed in the cadaveric specimens, we postulated that percutaneous calcaneal displacement osteotomy is a safe, predictable, and advantageous alternative compared with open techniques for osteotomy and could result in reduced postoperative complications. The results of this investigation remain to be confirmed in the clinical setting.     

Monoaxial external fixation of the calcaneus: An anatomical study assessing the safety of monoaxial pin insertion

The use of external fixation for intra-articular calcaneal fractures is increasing in popularity. Studies have shown fine wire and monoaxial external fixation to be a viable surgical alternative to more invasive methods of open reduction and internal fixation of the calcaneus. However, there is an absence of literature that quantifies the risk of pin insertion for monoaxial fixation.This study aimed to determine the safety of inserting monoaxial pins within the calcaneus to house the Orthofix Calcaneal Mini-Fixator. Five formalin embalmed cadaveric ankle and lower leg specimens were inserted with six monoaxial pins. Careful dissection then revealed the presence of the tendons of peroneus longus and brevis, the sural nerve and the small saphenous vein in relation to these pins. Measurements from each pin to each of these structures were made as the structures transected lines drawn from each pin to two palpable bony landmarks: the inferior tip of the lateral malleolus and the posterosuperior calcaneus. In doing this, the risk posed by each pin could be evaluated. We found that two particular pins, those used to hold the articular surface of the subtalar joint in a reduced position, posed a larger risk of injury to surrounding structures than the remaining pins. These findings therefore suggest that monoaxial fixation of the calcaneus using a six pin approach is a relatively safe method of rectifying calcaneal fractures and thus may serve as a welcome alternative to other methods of calcaneal fixation.     

Characteristics of anterior inferior calcaneal cortex

BackgroundMinimal invasive surgery of calcaneal fracture provided satisfactory outcomes. In tongue type calcaneal fracture, percutaneous screw usually purchases in anterior inferior calcaneal cortex. However, there was no detail about the cortex of anterior inferior calcaneus so the surface anatomy and cortical thickness of this area were studied.Methods88 calcaneus from embalmed cadavers were enrolled. Anterior part of the inferior cortex was identified. Surface anatomy was examined. Length, anterior and posterior widths were measured. Anterior inferior calcaneal cortex was divided into anterior, middle and posterior segments. The cortical thickness at middle, medial most and lateral most of 3 segments were measured.ResultsAnterior inferior calcaneal cortex was a long trapezoidal shape with well-defined borders as a dense and thick cortical bone, convex relief from medial and lateral walls. Mean(SD) length was 33.40(3.46) millimeters (mm). Median(min,max) of anterior and posterior width were 10.50(8.21,19.26) mm and 14.00(10.05,20.42) mm, respectively. Mean(SD) of middle cortical thickness of anterior and middle segment were 3.12(0.76) and 3.72(0.74). Median(min,max) middle cortical thickness of posterior segment was 3.13(1.62,6.51) mm. Whereas, of the medial most were 1.31(0.78,3.11), 1.31(0.90,2.57) and 1.26(0.85,2.61) mm and of the lateral most were 1.17(0.67,2.64), 1.38(0.80,2.55) and 1.31(0.84,2.61) mm, respectively. Inter-intraobserver reliabilities of the measurements were >0.79. The statistical analysis showed the middle cortex is significantly the thickest (P < 0.001) and posterior width is significant wider than the anterior (P < 0.001).ConclusionsAnterior inferior calcaneal cortex has special characteristics in term of surface anatomy, width and thickness. For the percutaneous screw insertion from posterosuperior to anterior inferior calcaneus in tongue type calcaneal fracture, we recommend that screw should purchase in middle cortex due to maximal cortical thickness as well as its cortical width could accept 6.5 or 7.0 mm screw without screw extrusion.     

胫骨平台后髁骨折的治疗

目的:探讨胫骨平台后髁骨折的治疗方法。方法:9例胫骨平台后髁骨折患者,男6例,女3例;年龄24⁵8岁,平均36岁。左侧2例,右侧7例。骨折类型:后外侧髁骨折5例,后内侧髁骨折1例,双髁骨折3例,采用后内和（或）后外侧入路复位内固定治疗。结果:9例均获随访,随访时间6³2个月,平均18·4个月。患膝关节功能评定按Hohl评分标准:优7例,良2例。关节面未见明显塌陷情况。结论:膝关节的后内和（或）外侧入路较前侧入路能更充分暴露后关节间隙及胫骨平台后髁,为骨折的直视复位和植骨内固定提供了良好的操作空间。     

松质骨螺钉与加压螺栓在微创钢板治疗跟骨骨折中应用的病例对照研究

目的:探讨采用斯氏针撬拨复位,足跟外侧微创小切口钢板全螺纹松质骨钉内固定治疗跟骨关节内移位骨折的临床疗效。方法:2009年9月至2012年6月共收治80例闭合性跟骨关节内移位骨折患者,分为对照组和治疗组,每组40例。对照组:男21例,女19例;年龄23～64岁,平均(39.1±11.7)岁;采用自断型加压螺栓钢板内固定。治疗组:男24例,女16例;年龄21～67岁,平均(39.6±14.3)岁;应用全螺纹松质骨螺钉钢板内固定。记录术中松质骨螺钉与加压螺栓进行固定的时间及手术的出血量,观察术后足底内侧神经的损伤例数,术后1年复查时测量B觟hler角和Gissane角以及跟骨的宽度的矫正度数,1年后行内固定物取出,应用AOFAS踝-后足评分标准评定疗效。结果:患者术后均获得随访,时间9～32个月,平均16个月。治疗组手术时间短、创伤小,术后B觟hler角及跟骨宽度恢复满意,减少了足内侧神经血管损伤,骨折愈合后易于取出,与对照组比较差异有统计学意义。结论:全螺纹松质骨螺钉替代自断型加压螺栓固定跟骨骨折临床疗效相同,但手术时间缩短、出血少、易于取出,避免了内侧神经血管的损伤,降低了并发症的发生。     

Surgical techniques: how I do it? Mini open reduction and fixation of calcaneal fractures with fine wire circular frames

Patients with calcaneal fractures associated with significant soft tissue swelling or open wounds are not ideal candidates for extensive incisions and open reductions with internal fixation. Fine wire frame external fixateurs are being used for the treatment of displaced intraarticular fractures of the calcaneus with soft tissue compromise or in patients with moderately displaced fractures. In this paper, we present our surgical technique of treating displaced intraarticular calcaneal fractures with circular frame external fixateurs.     

Evaluation of anatomic risk factors using magnetic resonance imaging in non-contact anterior cruciate ligament injury

BackgroundThe purpose of our study was to compare the significance of the tibio-femoral morphological variables (notch width index, notch shape index, intercondylar notch angle, medial and lateral tibial slopes) in predicting non-contact ACL (anterior cruciate ligament) injuries and to compare these factors between genders in South Asian population. The author hopes to provide a comprehensive analysis on the risk factors which would help in betterment of the patients at danger for anterior cruciate ligament injury.Materials and methodsA total of 110 MRI knees of patients with 55 subjects of noncontact ACL injury and 55 age and sex matched controls were included in a retrospective study. Notch width index, notch shape index, intercondylar notch angle were assessed in axial and coronal MR imaging along with medial and lateral posterior tibial slopes. Morphology of the notch was also assessed.ResultsACL injured group were found to have a statistically significant narrow notch width index and decreased intercondylar notch angle with increased lateral posterior tibial slope. Type-A notches were found to have increased risk of having ACL injuries. Gender comparative results showed no statistically significant differences.ConclusionACL tears are associated with decreased notch width index, intercondylar notch angle and increased lateral posterior tibial slope. Type-A notches are seen to have increased risk for ACL injuries.     

Two different flaps for reconstruction of gunshot wounds to the foot and ankle in a child

An 8-year-old boy was shot in his right foot and ankle, which resulted in soft tissue lesions of the medial malleolus and lateral calcaneus, fracture of the medial malleolus, and partial loss of the calcaneus. We designed a distally based sural flap and a posterior tibial perforator flap for reconstruction of soft tissue defects at the lateral aspect of the calcaneus and the medial malleolus, respectively. Both flaps survived successfully, and the boy had a normal gait during follow-up.     

跟骨外侧延长L形切口并发症的危险因素分析

目的 :探讨跟骨外侧延长"L"形切口治疗闭合性跟骨骨折术后发生切口并发症的相关危险因素,明确降低切口并发症的有效干预手段。方法:回顾性分析2011年1月至2015年1月收治的285例(315足)行跟骨外侧延长"L"形切口治疗闭合性跟骨骨折患者的临床资料,对可能影响术后切口并发症的18个临床相关危险因素进行单因素分析,对存在统计差异的变量再给予多因素Logistic回归分析。结果:285例(315足)共有29例(30足)出现切口并发症,其中切口皮缘红肿渗出、不愈合9足,皮缘发黑坏死或者切口裂开16足,皮肤软组织浅层感染3足,骨髓炎2足。单因素分析结果显示:坠落高度(P=0.017)、糖尿病病史(P=0.026)、吸烟史(P=0.001)、手术时间(P=0.003)4个因素差异有统计学意义,将这些因素再进行多因素Logistic回归分析,发现糖尿病(P=0.029)、吸烟史(P0.001)、手术时间(P=0.018)是跟骨外侧延长"L"形切口术后并发症的危险因素。结论 :术前戒烟、积极控制血糖以及熟悉手术操作,有效减短手术时间可以减少跟骨外侧延长"L"形切口并发症的发生率。     

The multi-ligament ankle fracture: Epidemiology,key anatomical findings and fixation strategies in unstable open injuries

BackgroundAnkle fracture surgery has traditionally focussed on restoration of bony anatomy, with fixation of the malleoli and syndesmotic stabilisation where applicable. However, high energy open fracture-dislocations can also result in periosteal stripping of the stabilising capsuloligamentous attachments. As such, restoration of osseous anatomy alone may not result in sufficient articular stability.ObjectivesIn this series from a level 1 trauma centre, we report a subset of highly unstable open ankle fractures with combined capsuloligamentous injuries, in which restoration of osseous anatomy did not result in a stable joint. Supplementary soft tissue reconstruction and other stabilisation techniques were required.MethodsRetrospective case series of eligible patients from a level 1 trauma centre. Inclusion criteria were open ankle fractures with tibial extrusion (AO 44) and persistent instability post-bony fixation, age over 18 years and non-diabetic. Analysis of injury pattern, mechanism, pathological anatomy, soft tissue and orthopaedic reconstruction methods was performed.Results16 patients were identified during the study period who met the eligibility criteria, out of 95 open ankle fractures treated between January 2017–December 2020. Most patients were under 65 (n = 13; 81.3%) and sustained combined or isolated injuries of the deltoid ligament, anterior capsule, lateral ligament complex (ATFL±CFL) and tibialis posterior retinaculum. The commonest injury pattern was tibial extrusion via a medial soft tissue defect with deltoid ligament and anteromedial capsule rupture. Associated syndesmotic instability and fixation was common (n = 10; 62.5%). Supplementary stabilisation methods to standard bony fixation included capsuloligamentous reconstruction or repair, “ORIF+” external fixation, or conversion to primary fusion or hindfoot nail. Six patients required either local or free flap soft tissue coverage.ConclusionsA subset of up to 20% of open ankle fractures require supplementary fixation beyond anatomical restoration of the bony anatomy due to persistent ligamentous instability. They are associated with capsuloligamentous and syndesmotic disruption, more commonly affecting the medial structures. These rare injuries can be defined as multi-ligament ankle fractures. Surgeons should be aware of this subset and be able to recognise where supplementary stabilisation strategies are required.     

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.     

Technique for Minimally Invasive Reduction of Calcaneal Fractures Using Small Bilateral External Fixation

Soft tissue complications are well known after extensile exposure of the calcaneus for open reduction internal fixation of fractures. A variety of recommendations have been proposed to reduce soft tissue healing issues and infection. Despite these recommendations, some surgeons believe that soft tissue complication rates have remained unacceptably high with lateral extensile incisions. Recently, interest in minimally invasive repair techniques for calcaneal fractures has increased. These techniques have been purported to avoid some of the common soft tissue problems seen with calcaneal open reduction internal fixation. The focus of the present communication is to share a minimally invasive surgical method for the reduction and fixation of calcaneal fractures. Percutaneous fixation of the posterior facet fragments can be facilitated by distraction of the fractured calcaneus using skeletal traction and a small bilateral external fixator. Final stability is achieved with a combination of the external fixator and percutaneous screws and/or wires. We present our technique and discuss recent published studies on minimally invasive repair of calcaneal fractures.     

膝关节半月板根部附着区的解剖学测量

目的:测量国人膝关节内外侧半月板前后根部附着区的解剖学数据,为临床修复半月板根部损伤提供解剖学基础。方法:选取30个国人成人尸体膝关节标本,其中男16例,女14例;死亡年龄35～68(55.6±7.8)岁。对半月板根部附着区结构进行解剖,测量内外侧半月板根部附着区中心点与胫骨内外侧髁间棘、后交叉韧带前缘、内侧胫骨平台软骨后方外侧缘及外侧胫骨平台软骨后方内侧缘等标志点的位置关系和各个附着区的面积。结果:内侧半月板后根部附着区:中心点位于胫骨内侧髁间棘后方(11.73±3.10) mm、外侧(2.77±0.86) mm,后交叉韧带前缘前(2.76±0.76) mm,内侧平台软骨外侧缘外(3.92±0.22) mm,附着区面积(31.29±5.18) mm~2。内侧半月板前根部附着区:中心点位于胫骨内侧髁间棘前方(25.40±5.27) mm、外侧(3.01±0.86) mm,附着区面积(46.18±11.60) mm~2。外侧半月板后根部附着区:中心点位于胫骨外侧髁间棘后方(4.51±1.35)mm、内侧(1.85±0.34) mm,后交叉韧带前缘前(6.91±1.11) mm,外侧平台软骨内侧缘内(3.16±0.96) mm,附着区面积(44.10±6.23) mm~2。外侧半月板前根部附着区:中心点位于胫骨外侧髁间棘前方(12.97±2.92) mm、外侧(1.31±0.22) mm,附着区面积(60.84±14.98) mm~2。结论 :该试验定量描述内外侧半月板前后根部附着区的面积以及其中心点与相应标志点的位置关系,为临床修复半月板根部损伤提供一定的解剖学参考。     

Radial forearm free flap for coverage of postoperative lateral heel wounds after open reduction and internal fixation of the calcaneus

For intraarticular calcaneus fractures, open reduction and internal fixation has become commonplace for the reduction of morbidity of postinjury arthritis. Despite adequate surgical results, there are often associated postoperative wound complications. The purpose of this study was to describe a unique application of the radial forearm free flap for coverage of lateral postoperative heel defects seen after calcaneal fixation. Seven lateral heel wounds after open reduction of calcaneal fractures in 6 patients were covered with radial forearm free flaps. The technique used involved passage of the pedicle of the laterally placed flap anteriorly to the Achilles tendon so that it can be anastomosed to the posterior tibial artery. Flap application was 100% successful, with good functional and cosmetic results in all patients. The radial forearm free flap provides a quick, reliable, and easily harvested source of coverage for lateral heel wounds seen after open reduction and internal fixation of the calcaneus. Tunneling of the flap pedicle anterior to the Achilles tendon is simple and provides the additional advantages of access to reliable vessels, reduced scarring, and avoidance of further wound problems often seen with incisions used to access the anterior tibial artery.     

Minimally Invasive Medialising Calcaneal Osteotomy (MIMCO)

BackgroundMedialising calcaneal osteotomy is a common procedure usually done in tandem with other procedures like lateral column lengthening or subtalar arthroereisis, flexor digitorum longus transfer, with or without heel cord lengthening, spring ligament repair and tibialis posterior tendon debridement for the treatment of symptomatic adult – acquired flatfoot deformities (AAFD). The procedure has historically been done via open approaches which are associated with the risk of wound complications and nerve injury. Recently there has been a shift towards more minimally invasive techniques.MethodsMinimally invasive medialising calcaneal osteotomy (MIMCO) is performed percutaneously under fluoroscopy using a high torque, low speed, and saline cooled burr and can be secured with a single cannulated screw, with minimal soft tissue dissection.Results and ConclusionsMIMCO provides surgeons with a safe and reliable tool to correct hindfoot deformities that is comparable to the open procedure but with added potential advantages of decreased postoperative pain, wound complications and iatrogenic injury to neurovascular structures.     

Percutaneous balloon calcaneoplasty versus open reduction and internal fixation (ORIF) for intraarticular SANDERS 2B calcaneal fracture: Comparison of primary stability using a finite element method

IntroductionFractures of the calcaneus are common, with 65% being intra-articular, which can lead to a major impairment of the patient's quality of life. Open reduction and internal fixation with locking plates can be considered as gold-standard technique but has a high rate of post-operative complications. Minimally invasive calcaneoplasty combined with minimally invasive screw osteosynthesis is largely drawn from the management of depressed lumbar or tibial plateau fractures. The hypothesis of this study is that calcaneoplasty associated with minimally invasive percutaneous screw osteosynthesis presents biomechanical characteristics comparable with conventional osteosynthesis.Materials and methodsEight hind feet were collected. A SANDERS 2B fracture was reproduced on each specimen, while four calcanei were reduced by a balloon calcaneoplasty method and fixed with a lateral screw, four others were manually reduced and fixed with conventional osteosynthesis. Each calcaneus was then segmented for 3D finite element modeling. A vertical load was applied to the joint surface in order to measure the displacement fields and the stress distribution according to the type of osteosynthesis.ResultsAnalyses of the intra-articular displacement fields showed lower overall displacements in calcaneal joints treated with calcaneoplasty and lateral screw fixation. Better stress distribution was found in the calcaneoplasty group with lower equivalent joint stresses. These results could be explained by the role of the PMMA cement as a strut, enabling better load transfer.ConclusionBalloon Calcaneoplasty combined with lateral screw osteosynthesis has biomechanical characteristics at least comparable to locking plate fixation in the treatment of SANDERS 2B calcaneal joint fractures in terms of displacement fields and stress distribution under the premise of anatomical reduction.