The effect of knee flexion on the popliteal artery and its surgical significance

Total knee replacement and high tibial osteotomy are common orthopaedic operations with low complication rates. Such surgery is in close proximity to the popliteal artery (PA), the behaviour of which during flexion of the knee is poorly understood. We used Duplex ultrasonography to determine the distance of the PA from the posterior tibial surface at 0 degrees and 90 degrees of flexion in 100 knees. When the knee was flexed the PA was closer to the posterior tibial surface at 1 to 1.5 cm below the joint line in 24% and at 1.5 to 2 cm below the joint line in 15%. There was a high branching anterior tibal artery in 6% of knees. We provide an anatomical account to help to explain our findings by using cadaver dissections, arteriography and static MRI studies.     

全膝关节置换术中腘血管损伤的危险三角区域

 目的 探讨全膝关节置换术中腘血管损伤的危险区域。方法 回顾性分析2012年5至12月拍摄的1 291例膝关节MRI片,男564例,女727例;年龄16～87岁,中位年龄37岁;右侧565例,左侧726例。在横断位MRI片上测量膝关节髁上连线水平腘动脉与股骨外侧髁的最短距离（PA-LFC）、关节线水平腘动脉与后关节囊的距离（PA-PC）、关节线以下10 mm水平腘动脉与胫骨后方皮质的距离（PA-PTC）;在矢状位MRI片上测量腘动脉与胫骨后方皮质的最短距离（PA-PTCs）及腘动脉与后十字韧带的内外侧关系。取6具新鲜冰冻尸体膝关节标本,明确腘动脉的位置,测量其与膝关节囊及腘肌的距离。结果 1 291例膝关节MRI中出现腘动脉高位分叉变异17例（1.32％,17/1 291）。PA-LFC、PA-PC、PA-PTC及PA-PTCs分别为（4.89±1.80）mm、（4.05±1.43） mm、（3.61±1.39）mm及（3.58±1.04）mm。膝关节积液增加PA-LFC和PA-PC的数值,但不增加PA-PTC和PA-PTCs的数值。腘动脉总是位于血管神经束最前方。在关节线水平,腘动脉均位于后十字韧带内缘的外侧。尸体解剖显示膝关节线距腘肌上缘（1.13±0.23） cm,该段腘动脉及其分支构成一个三角形区域,紧贴关节囊和胫骨皮质,三角形后方为腘动脉主干、膝外下动脉、膝正中动脉等密集分布的区域。结论 腘动脉损伤危险三角形区域后方存在重要的缺乏足够软组织保护的血管,包括腘动脉、膝外下动脉、膝正中动脉及一些无名小动脉,在全膝关节置换术中应注意保护。     

Anatomic study of the middle genicular artery

PURPOSE: To study the anatomy of the middle genicular artery and thus mitigate the risk of vascular injury in knee surgery. METHODS: The course, anatomic relations, and variations of the middle genicular artery in 8 cadavers (4 men and 4 women) were studied. RESULTS: The middle genicular artery originated from the anterolateral surface of the popliteal artery in the popliteal fossa, 3 to 5 cm proximal to the joint line either alone or having a common origin with the lateral genicular artery. Its diameter varied from 2 to 4 mm and it was 3 to 5 cm long. It was accompanied by 2 venae comitantes. This vascular bundle, including the middle genicular artery, ran distally, anterior to the popliteal artery, and posterior to the joint capsule, sandwiched between them. Distally it pierced the posterior joint capsule and became intra-articular. The relation of the middle genicular artery to the popliteal artery altered with the position of the knee joint. This alteration was secondary to the distal gliding of the popliteal artery with knee flexion. The middle geniculate artery formed an angle of 15 to 30 degrees to the popliteal artery when the knee was extended, which became almost a right angle when the knee was flexed past 90 degrees. CONCLUSION: Care must be taken when arthroscopic or open intra-articular surgery is performed in the posterior part of the knee joint using chondrotomes and saws, particularly with limited vision. Sharp dissection and diathermy under direct vision should be safer.     

膝关节周围动脉为蒂骨膜(骨)瓣的应用解剖及临床意义

目的 为带蒂骨膜（骨）瓣移位治疗膝关节周围骨不连、骨缺损提供解剖学依据。方法 在30侧经动脉灌注的成人下肢标本上,观察并测量膝关节周围动脉网有关血管的起始、走行、口径、分布及其吻合情况。结果 膝关节周围存在着丰富的血供,其主要由Guo动脉、股动脉、胫前动脉、胫后动脉的终末支及相互间的交通支和吻合网恒定构成。结论 在膝关节周围动脉为蒂的骨膜（骨）瓣,是进行局部转位和吻合血管游离移植的重要供区之一。     

Injury to the popliteal artery and its anatomic location in total knee arthroplasty.

Injury to the popliteal artery during total knee arthroplasty (TKA) is a devastating complication. Although infrequent, these injuries can result in the need for further surgery, including revascularization or possibly even amputation. Several mechanisms are capable of producing direct trauma to the popliteal artery, including the use of posterior ret ractors. We investigated the proximity of the popliteal artery to the tibial joint surface during TKA to identify crucial steps in the procedure at which the artery was at highest risk for injury. TKA was performed on cadaveric specimens, and serial intraoperative arteriograms were taken throughout the procedure, demonstrating the potential for arterial injury by the instrumentation. Additionally, 50 transverse magnetic resonance imaging scans of unrelated knees were analyzed for the position of the popliteal artery relative to the midline of the tibial plateau as well as at a level 5 to 10 mm below this, at the site of a typical resection during TKA. All of the arteriograms showed the artery to be a lateral structure at the joint line. Additionally a posterior retractor placed the artery at risk when it was placed in a position lateral to the posterior cruciate ligament or when it was injudiciously inserted more than 1 cm into the soft tissues. Hyperextension of the knee, which might occur during preparation of the patella, produced dramatic tenting of the artery over the posterior joint line. These results demonstrate that the popliteal artery is at significant risk during TKA, particularly if posterior retractors are placed in a position lateral to the midline of the joint. Both hyperflexion and especially hyperextension produced severe deformities and kinking of the artery and would particularly jeopardize an artery with atherosclerosis. Our findings suggest that the popliteal artery may be at least risk during TKA if posterior retractors are placed medial to the midline of the tibial plateau and if care is taken to avoid extremes of both flexion and extension.     

Prevalence and surgical significance of a high-origin anterior tibial artery

PURPOSE: To assess the prevalence of proximal high-origin anterior tibial artery and its surgical significance. METHODS: 100 knees were prospectively studied using colour Doppler ultrasonography. No patient had a history of lower-limb arterial pathology or previous knee surgery. All ultrasound images were assessed by a single experienced vascular technician to eliminate inter-observer variability. RESULTS: The mean age of the patients was 56 years (range, 21-96 years). Prevalence of the high-origin anterior tibial arterial pattern was 6%, greater than that reported by previous angiographic or cadaveric studies. In all patients with high-origin anterior tibial artery, the artery was in direct contact with the posterior cortex of the tibia. CONCLUSION: This highlights the danger of using sharp instruments in knee procedures that involve extension of osteotomy to the posterior tibial cortex, particularly high-tibial osteotomy and total knee replacement. Knowledge of the anatomical variations in the branching of the popliteal artery is important because damage to its branches can be limb- or life-threatening.     

下肢动脉硬化闭塞症侧支循环流出道的解剖学特点及临床应用初探

目的下肢动脉粥样硬化闭塞症（arterial sclerosis obstruction，ASO）末期常无远端流出道，对末期ASO患者膝上截肢的离断标本行血管灌注，通过解剖学研究评估侧支流出道构建的可能性及临床应用前景。方法在10例自愿捐赠的膝上截肢新鲜离体标本上向动脉内灌注红色乳胶，解剖观察胭动脉、胫前动脉、胫后动脉的病理改变，以及这些主干动脉侧支分布的规律。2005年9月-2007年4月，收治5例ASO患者，均为单侧。其中男3例，女2例；年龄68～81岁。均有6个月静息痛病史。下肢DSA示股动脉、胭动脉及分支均不显影，B超示胭动脉及分支基本闭塞，行胭动脉及分支探查、血循环重建术。结果解剖学实验结果：胭动脉、胫后动脉、胫前动脉管壁僵硬，动脉粥样斑块填满管腔。胭动脉及分支发出的侧支中，腓肠动脉开口于主干动脉的几率最大。所有侧支在膝周构建的侧支循环稀疏，而在小腿肌群内可形成相对丰富的侧支循环。临床应用结果：5例手术均顺利，术后皮温逐渐增高，血氧饱和度术前为0，术后6h逐渐达90％～100％。获随访3～12个月，患者感觉下肢症状明显改善，静息痛消失，下肢溃疡逐渐愈合。B超示胭动脉吻合口处血流大部进入侧支循环，远侧胫前、胫后动脉的血流量并不多。结论通过临床解剖发现，侧支流出道的构建是可行的，临床应用结果提示这一方法是解决晚期ASO患者的一种有效途径。     

Popliteal vessels in knee surgery. A magnetic resonance imaging study.

Popliteal artery injury during surgery of the knee is rare but can have devastating consequences. The position of knee flexion has been thought to be protective for the popliteal artery, allowing it to fall back from the knee joint. No prior study has provided in vivo cross sectional evidence of the behavior of the popliteal vessels during knee flexion with the effect of gravity. Magnetic resonance imaging was used in nine volunteers to measure the distance of the popliteal artery and veins from the posterior proximal tibia at two levels corresponding to the levels of osteotomy in total knee arthroplasty and in high tibial osteotomy. Scans were taken with the knee in full extension and at 90 degrees flexion with the patient in the supine position, allowing for the effect of gravity. Considerable variation in behavior of the vein and the artery was observed at the high tibial osteotomy cross sectional level and the total knee arthroplasty cross sectional level. In two knees at the high tibial osteotomy cross sectional level and in two knees at the total knee arthroplasty cross sectional, level the artery moved closer to the posterior tibia with knee flexion. Even with the effect of gravity included, knee flexion does not guarantee removal of the popliteal vessels from potential harm during surgery of the knee.     

Effect of inflow and outflow sites on the results of tibioperoneal vein grafts

We have reviewed our experience with the tibial vessel bypass operation and have found the overall patency and limb salvage rates to be acceptable. Patients were divided into two groups based on the site of the proximal anastomosis. In Group I, the proximal anastomosis was at the common femoral artery and in Group II, the proximal anastomosis was at the distal superficial femoral artery or the popliteal artery. The patients in the two groups were similar with regard to indications for operation, age, and sex. However, in Group I, 35 percent of the patients were diabetic and in Group II, 74 percent of the patients were diabetic. In the Group I patients, the 72 month graft patency rate was 65 percent with a limb salvage rate of 75 percent. In the Group II patients, the 72 month patency rate was 81 percent with a limb salvage rate of 89 percent. Some possible explanations for this slightly better result in Group II patients are discussed. All tibial bypasses were divided into three groups based on the recipient tibial artery. Analysis revealed that the 72 month patency rates were as follows: the anterior tibial artery 63 percent, the posterior tibial artery 81 percent, and the peroneal artery 80 percent. These differences were not significant but indicate, as others have recently pointed out, that the peroneal artery is indeed an acceptable recipient artery for tibial bypass surgery.     

The effect of obesity on the anatomical relationship of the popliteal artery and tibial nerve in the proximal and distal popliteal fossa: relevance to popliteal sciatic nerve block and a traceback technique using the popliteal artery

Study ObjectiveTo determine the effect of body mass index (BMI) on the relationship of the popliteal artery to the sciatic and tibial nerves in the popliteal fossa.DesignProspective, observational study.SettingUniversity medical center.SubjectsOne hundred patients scheduled for magnetic resonance imaging scans of the knee.MeasurementsBMI was recorded and magnetic resonance imaging scans were assessed at 3 different measurement points along the femur for the distance and angle between the popliteal artery and tibial nerve, or sciatic nerve if the sciatic nerve had not bifurcated at the measurement point.Main ResultsAt the distal femur, the tibial nerve was a mean of 2.9 mm from the popliteal artery. The nerve was consistently posterior to the artery; however, it was variably located medial or lateral to the artery. At the 5- and 8-cm measurement points, the nerve was 10.0 and 16.1 mm (SD, 4.1 and 5.2 mm), and 31° and 44° (SD, 15° and 16°) lateral to the popliteal artery, respectively. Zero degree was defined as directly posterior to the artery. Increasing BMI was correlated with increasing distance between the nerve and the artery at the 5- and 8-cm measurement points (r= 0.36 P> |t| .000 and .45 P> |t| .002).ConclusionsAt 5 cm proximal to the distal femoral condyles, the popliteal artery is a reliable sonographic landmark to locate the tibial nerve due to the close proximity and consistent location of the nerve 1 cm posterolateral to the artery, with only a moderate effect of BMI.     

复合血管序贯式旁路移植术治疗慢性肢体缺血的临床分析

目的:探讨复合血管序贯式下肢动脉旁路术治疗慢性下肢缺血的效果。方法:回顾性分析3年内采用复合式血管序贯式动脉血管重建的25例慢性下肢缺血患者的临床资料。复合血管由聚四氟乙烯（PTFE）人工血管及自体静脉组合而成。PTFE近心端与股总动脉吻合，远端与孤立腘动脉吻合；自体静脉从PTFE血管远端发出并与小腿的胫或腓动脉吻合。结果:自体静脉远端吻合口止于胫前动脉5例，胫后动脉8例，腓动脉12例。术后1，2，3年累积通畅率分别为78%， 72%， 61%。二期累积通畅率分别为83%，77%，68%。救肢率分别为83%，83%，73%。结论:复合血管序贯旁路术治疗慢性肢体缺血远期通畅率较高，具有较好的救肢效果，是解决自体静脉不足的合理选择。     

Surgical significance of popliteal arterial variants. A unified angiographic classification

Distal popliteal arterial variations may influence the success of femorodistal popliteal and tibial arterial reconstructions. Two patients whose bypass procedures were initially unsatisfactory because of a poor choice for anastomosis stimulated a review of variations in the distal popliteal artery in 1000 femoral arteriograms. The popliteal arterial anatomy could be assessed in 605 extremities and the tibial arterial anatomy in 495 extremities. Seventy-five variant cases were identified. Normal branching of the popliteal artery was present in 92.2%. Among the 7.8% incidence of variants, the majority (72%) were either high origin of the anterior tibial artery or a trifurcation pattern. Of variant patterns to the foot (5.6%), the most common was that in which the supply to the distal posterior tibial artery arose from the peroneal artery. We propose a unified classification of the popliteal and tibial arterial variations that encompasses both anatomic areas. Variant arterial supply to the foot can be suspected when the infrapopliteal vessels show a hypoplastic or aplastic anterior or posterior tibial artery and compensatory hypertrophy of the peroneal artery. Knowledge of these variants is important to angiographers and vascular surgeons.     

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     

Variations in anatomy of the popliteal artery and its side branches

Knowledge of anatomic variations of the popliteal artery is essential for the management of peripheral vascular disease and in orthopedic surgery. The aim of this study was to perform an overview of the literature describing variations of the popliteal artery. To identify relevant literature, we performed a systematic search on MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews. We included 4 studies of anatomic dissections and 11 radiologic retrospective series, comprising 7671 limbs, and a variation in popliteal branching was seen in almost 10%. The 3 most frequent variations in branching are a high origin of the anterior tibial artery, the trifurcation of the anterior tibial artery, peroneal artery, and posterior tibial artery, and a hypoplastic or aplastic posterior tibial artery. Awareness of the terminal branching pattern of the popliteal artery before intervention enhances the planning for successful operations and may reduce the incidence of serious, unexpected arterial injury.     

膝关节周围创伤伴腘窝血管伤的早期诊断与救治

目的 :探讨膝关节周围创伤伴腘窝血管伤的早期诊断与救治。方法 :回顾性分析2007年1月至2013年1月15例膝关节周围骨折、脱位伴腘窝血管损伤患者的临床资料,其中男9例,女6例;年龄26~62岁,平均39.2岁。结合临床症状、体征,运用血氧饱和度监测仪、彩色超声、DSA介入造影及手术探查等方法明确血管损伤,分别采用组合式外固定支架、钢板螺钉股骨髁逆行交锁钉内固定骨折及膝关节脱位,并根据具体情况对损伤血管进行取栓、修补、自体静脉移植重建血循环,分析手术时间、住院天数、保肢指数、输血量、医疗费用及感染发生情况,明确早期诊断及有效救治的作用。结果:本组患者死亡1例,截肢8例,6例手术成功修复腘动脉、胫前及胫后动脉。6例肢体存活患者随访12~60个月,平均28.3个月。保肢成功且关节功能优良4例。结论:膝关节周围创伤伴腘窝血管伤具有伤情复杂且严重、易误漏诊、预后差、保肢风险高等特点,应结合患者的创伤机制、损伤部位局部解剖特点、临床表现及适当的辅助检查来把握膝关节周围创伤伴腘窝血管伤的早期诊断,掌握合适的保肢与截肢指征以高效救治患者。     

Aufklappende Osteotomie des Tibiakopfes

Background

Lesions of the popliteal artery during high tibial osteotomy are rare complications, consequently the majority of publications are case related. The interval between surgery and diagnosis is reported to be as long 3 years; therefore, the current literature probably does not reflect the true incidence of vascular injuries.

Objective

The case reports published in the literature were further evaluated. The focus was on the normal vascular anatomy of the popliteal region and anatomical deviations that predispose to vascular injury. As the flexion angle of the knee joint is considered to be decisive for vascular injury, this aspect was also an additional focus. For the unlikely event of a vascular injury, recommendations are presented which indicate diagnostic and therapeutic decisions.

Methods

We analyzed the available literature and present own magnetic resonance imaging (MRI) investigations of the popliteal artery with different angles of flexion in six healthy volunteers.

Results and discussion

A variation of the origin of the anterior tibial artery with a course between the posterior tibial cortex and the popliteal muscle was found in 6?% of all patients and predisposes to an accidental injury during osteotomy. The results in the literature and our own MRI findings suggest that a flexion angle of 90° facilitates anatomical dissection and osteotomy but cannot be regarded as a reliable protection against vascular injury.     

腘窝中间动脉蒂混合供血皮瓣修复儿童腘窝瘢痕挛缩

目的探讨腘窝中间动脉蒂混合供血皮瓣的血供特点及修复儿童腘窝瘢痕挛缩松解后创面的可行性。方法 2008年1月-2010年10月,对6例腘窝瘢痕挛缩患儿行瘢痕松解、腘窝中间动脉蒂混合供血皮瓣移位修复。男2例,女4例;年龄2岁2个月～10岁。均为热水烫伤。腘窝瘢痕挛缩松解后创面范围5 cm×4 cm～10 cm×8 cm,皮瓣切取范围6 cm×4 cm～11 cm×9 cm。供区直接缝合1例,游离植皮5例。结果术后6例患儿皮瓣完全成活,无血管危象或皮瓣坏死发生。供、受区切口均Ⅰ期愈合,供区植皮均成活。术后患儿均获随访,随访时间12～24个月,皮瓣色泽、质地、外形良好。1例患儿术后6个月腘窝手术切口出现较厚增生性瘢痕,膝关节活动范围0～175°,随访15个月无明显变化;余5例膝关节活动范围0～180°,无跛行。结论腘窝中间动脉蒂混合供血皮瓣血供可靠,手术操作简便,修复儿童腘窝瘢痕挛缩松解后创面效果理想。     

血栓闭塞性脉管炎合并动脉硬化闭塞导致下肢缺血的手术治疗

目的 探讨下肢血栓闭塞性脉管炎(thmmboangiitis obliterans,TAO)合并动脉硬化闭塞症(arteriosclerosis obliterans,ASO)手术治疗效果.方法 回顾性分析2007年治疗的TAO合并ASO 6例患者的资料.2例行腹主动脉切开取栓+内膜剥脱+腹主动脉-股深动脉人工血管旁路移植-胭动脉人工血管-小腿动脉自体大隐静脉旁路移植术,1例行腹主动脉切开取栓+内膜剥脱+腹主动脉-右股深动脉人工血管旁路移植-膝下胭动脉人工血管旁路移植术;1例行左髂总动脉-左股深动脉人工血管旁路移植一胫前动脉自体大隐静脉原位移植术,1例行左侧人工血管切开取栓+左股深动脉成形-膝下腘动脉人工血管旁路移植术,1例行右股总动脉-左股总动脉人工血管旁路移植-胫后动脉自体大隐静脉旁路移植术.结果 5例患者术后恢复顺利,1例于术后当天出现股动脉-腘动脉人工血管和远段的大隐静脉桥血栓形成,立即再次手术行人工血管和大隐静脉切开取栓术,并同时行胫后动静脉吻合.6例患者均痊愈出院,无死亡病例.5例患者的下肢远端静息痛完全缓解,1例部分缓解.足部溃疡的2例创面明显缩小,无感染发生.所有患者得到随访,平均随访为6.5个月,3例足部溃疡愈合.1例术后3个月出现左股部切口感染,最终行膝上截肢处理,残端一期愈合.其他5例患者的移植血管通畅,症状缓解.结论 对TAO合并ASO患者如果手术治疗方式恰当,可以取得比较好的疗效.     

Flexion of the knee increases the distance between the popliteal artery and the proximal tibia: MRI measurements in 15 volunteers

We determined which angle of flexion best prevents popliteal artery injury during knee surgery. We took MRIs of the knee in the lateral position with the knee in 0°, 45°, 90°, and 120° of flexion in 15 volunteers. The shortest distance between the posterior cortex of the tibia and the popliteal artery was measured at various levels from the knee joint to 60 mm distally. At the level of the joint and 15 mm distally, the distance between the tibia and artery increased with increasing knee flexion. More distally, no significant difference was noted with increasing flexion. Flexion of the knee may minimize injury to the popliteal artery in procedures between the level of the joint and 15 mm distal to the joint.     

Flexion of the knee increases the distance between the popliteal artery and the proximal tibia: MRI measurements in 15 volunteers

We determined which angle of flexion best prevents popliteal artery injury during knee surgery. We took MRIs of the knee in the lateral position with the knee in 0 degrees, 45 degrees, 90 degrees, and 120 degrees of flexion in 15 volunteers. The shortest distance between the posterior cortex of the tibia and the popliteal artery was measured at various levels from the knee joint to 60 mm distally. At the level of the joint and 15 mm distally, the distance between the tibia and artery increased with increasing knee flexion. More distally, no significant difference was noted with increasing flexion. Flexion of the knee may minimize injury to the popliteal artery in procedures between the level of the joint and 15 mm distal to the joint.