Proximity of the posterior cruciate ligament insertion to the popliteal artery as a function of the knee flexion angle: Implications for posterior cruciate ligament reconstruction

Purpose: The purpose of this study was to determine if an optimal knee flexion angle existed that would minimize the risk of neurovascular injury from the passage of transtibial hardware during posterior cruciate ligament (PCL) reconstruction. Type of Study: Cadaveric. Materials and Methods: Fourteen fresh-frozen cadaveric knees were mounted in a Plexiglas apparatus that could be set at 5 different knee flexion angles (0°, 45°, 60°, 90°, and 100°) while joint distention was maintained. Each knee underwent magnetic resonance imaging in the axial and sagittal planes at each of the 5 flexion angles to determine the distance between the PCL tibial insertion and popliteal artery. Results: The mean distance, over all 5 flexion angles, between the PCL insertion and the popliteal artery in the axial plane was 7.6 mm, whereas the mean distance in the sagittal plane was 7.2 mm. There was a significant increase in distance with progressive flexion in both planes. Maximum mean distances were noted at 100° of flexion in both the axial (9.9 mm) and sagittal (9.3 mm) planes. An artificial line mimicking the path of a transtibial drill passed through the popliteal artery in 10 of 10 cases at the 0°, 45°, 60°, and 90° angles, and in 6 of 10 cases at the 100° angle. Conclusions: The results of this study suggest that increasing knee flexion reduces, but does not completely eliminate, the risk of arterial injury during arthroscopic PCL reconstruction.Arthroscopy: The Journal of Arthroscopic and Related surgery, Vol 16, No 8 (November-December), 2000: pp 796–804     

Proximity of the posterior cruciate ligament insertion to the popliteal artery as a function of the knee flexion angle

Purpose: The purpose of this study was to determine if an optimal knee flexion angle existed that would minimize the risk of neurovascular injury from the passage of transtibial hardware during posterior cruciate ligament (PCL) reconstruction. Type of Study: Cadaveric. Materials and Methods: Fourteen fresh-frozen cadaveric knees were mounted in a Plexiglas apparatus that could be set at 5 different knee flexion angles (0°, 45°, 60°, 90°, and 100°) while joint distention was maintained. Each knee underwent magnetic resonance imaging in the axial and sagittal planes at each of the 5 flexion angles to determine the distance between the PCL tibial insertion and popliteal artery. Results: The mean distance, over all 5 flexion angles, between the PCL insertion and the popliteal artery in the axial plane was 7.6 mm, whereas the mean distance in the sagittal plane was 7.2 mm. There was a significant increase in distance with progressive flexion in both planes. Maximum mean distances were noted at 100° of flexion in both the axial (9.9 mm) and sagittal (9.3 mm) planes. An artificial line mimicking the path of a transtibial drill passed through the popliteal artery in 10 of 10 cases at the 0°, 45°, 60°, and 90° angles, and in 6 of 10 cases at the 100° angle. Conclusions: The results of this study suggest that increasing knee flexion reduces, but does not completely eliminate, the risk of arterial injury during arthroscopic PCL reconstruction.     

Vascular risk associated with a posterior approach for posterior cruciate ligament reconstruction using the tibial inlay technique

This study evaluated the risk to the popliteal artery associated with the tibial inlay technique in posterior cruciate ligament (PCL) reconstruction. Barium was injected into the femoral arteries of eight fresh-frozen cadaveric knees and anteroposterior (AP) radiographs were obtained. Dissection of the fascia overlying the gastrocnemius muscle, identification of the interval between the medial head of the gastrocnemius and the semimembranosus, and lateral retraction of the medial head of the gastrocnemius (the Burks and Schaffer approach) was performed. Subsequently, a bicortical screw was placed from posterior to anterior through the tibia as is performed in the tibial inlay technique. A second AP radiograph was obtained. The distance from the center of the screw to the edge of the popliteal artery was measured using digital calipers. The closest any screw came to the popliteal artery was 18.1 mm, and the average distance was 21.1 mm (21.1 +/- 4.6 mm, range: 18.1-31.7 mm). When this distance was calculated as a percentage of the tibial plateau width, the smallest value was 19.2% (24% +/- 4.9%, range: 19.2%-35.1%). A posterior approach for a tibial inlay PCL reconstruction procedure appears safe with respect to the popliteal artery.     

Vascular risk associated with meniscal repair using Rapidloc versus FasT-Fix: comparison of two all-inside meniscal devices

ABSTRACT: Eight fresh-frozen cadaver legs (average age 72 years) were used to evaluate the risk to the popliteal artery related to the use of two all-inside meniscal repair devices, the Mitek RapidLoc (12.5 mumudegrees) and the Smith & Nephew FasT-Fix (curved). The lumen of the femoral artery was injected with barium. Anteroposterior (AP) and lateral radiographs were obtained to ensure visualization of the popliteal artery and its anatomic location. Both devices were inserted into the posterior horn of the lateral meniscus up to the hub of the needle under direct arthroscopic visualization. The distance between the needle and the artery was measured on the radiographs using calipers. The average distance from the needle to the popliteal artery was 0.5 mm (0.5 +/- 0.8 mm, range: 0-2 mm) on the lateral radiograph and 6.0 mm (6.0 +/- 6.2 mm, range: 0-19 mm) on the AP radiograph using the FasT-Fix system without the penetration limiter. None of the RapidLoc needles were within 20 mm of the popliteal artery on either of the radiographs. The FasT-Fix device came within 3 mm of the artery on both AP and lateral radiographs in 43% of the specimens. The risk to the popliteal artery was significantly greater using the FasT-Fix device compared to the RapidLoc device (P < .05). Although both instruments appear safe when used properly, the RapidLoc device seems to be safer with less risk to the popliteal artery than the current FasT-Fix meniscal repair device. When using the FasT-Fix device, the penetration limiter must be used to avoid the complications found in this study.     

全关节镜下膝关节后外复合体重建

目的 介绍全关节镜下腘肌腱重建、腘肌腱联合腘腓韧带重建或膝关节后外复合体(posterolateral corner,PLC)解剖重建的手术技术,探讨全关节镜下PLC重建治疗膝关节后外不稳定的效果.方法 2008年8月至2010年4月,共完成全关节镜下后十字韧带(posterior cruciate ligament,PCL)+PLC重建手术34例.患者在接受手术时平均年龄34.1岁(15～52岁);男32例,女2例;从受伤到手术平均10.7个月.所有病例均为陈旧性损伤,且均为复合韧带损伤.所有PCL损伤的病例都存在PLC损伤.合并前十字韧带损伤6例(17.6%),合并前十字韧带、内侧副韧带损伤2例(5.9%),合并内侧副韧带损伤5例(14.7%).对膝关节PLC损伤进行分型,采用不同的重建技术进行治疗.对于A型旋转不稳定,采用全关节镜下腘肌腱重建、腘肌腱联合腘腓韧带重建;对于C型后外不稳定,采用全关节镜下PLC解剖重建.结果 14例患者获得随访并进行二次关节镜检查,平均随访18.5个月(13～25个月).终末随访包括:膝关节查体、KT-1000测量、膝关节应力像和胫骨外旋稳定性.使用膝关节应力像测量胫骨后移程度,胫骨后移由术前平均15.56mm减少为术后5.16mm,手术前后差异有统计学意义.使用屈膝30°位胫骨外旋试验评估膝关节后外旋转不稳定.对比患侧与健侧胫骨外旋的差值,由术前平均14.92°减小为术后-0.22°,手术前后差异有统计学意义.术后患者平均屈曲受限4.23°,无伸膝受限.结论 对于膝关节PLC损伤导致的不稳定,采用全关节镜下PLC重建的手术技术,能够有效恢复膝关节后外旋转不稳定.这种手术技术能够与PCL重建联合应用.

Abstract：

Objectiye To introduce the surgical technique of arthroscopy assisted anatomical posterolateral corner (PLC) reconstruction,including popliteal ligament,popliteofibular ligament and lateral collateral ligament,and evaluate the results of this technique.Methods From August 2008 to April 2010,34arthroscopic posterior cruciate ligament (PCL) and PLC reconstruction surgeries were performed.The average age of the patients was 34.1 (15-52) years.There were 32 males and 2 females.The average time period from injury to surgery was 10.7 months.All patients were chronic injuries and combined ligament injuries,including PCL and PLC injuries.Some cases had other ligament injury,including 6 patients of anterior cruciate ligament (ACL) injury (17.6%),2 of ACL combined medial cruciate ligament (MCL) injuries (5.9%),and 5 of MCL injuries (14.7%).According to Fanellis classification,for type A posterolateral rotation instability,we performed arthroscopic popliteal ligament reconstruction or popliteal ligament combined popliteofibular ligament reconstruction.For type C posterolateral instability,we performed arthroscopic PLC anatomical reconstruction.Results During the follow-up period,14 patients had undergone a second look arthroscopic examination and removal of hardware.The average follow-up time was 18.5 months (13-25 months).At the final follow-up,physical examination,stability evaluation with KT-1000 and Telos stress view,and dial test were performed.The posterior displacement of the knee had decreased from 15.56 mm preoperatively to 5.16mm postoperatively.The external rotation instability had decreased from 14.92° preoperatively to -0.22°postoperatively.The average limitation of knee flexion was 4.23° and no knee extension was limited.Conclusion With the surgical technique of arthroscopy assisted anatomical PLC reconstruction,we can restore the external rotation stability of knee.This technique can be performed combine with PCL reconstruction.     

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.     

Vascular risk associated with bicortical tibial drilling during anteromedial tibial tubercle transfer

For select patients with persistent patellofemoral pain, the anteromedial tibial tubercle transfer (Fulkerson osteotomy) provides excellent clinical results. This procedure, indicated for patients with patellar malalignment, has become one of the most popular distal realignment procedures. One potential concern with this technique is the proximity of the posterior vascular structures during bicortical tibial drilling for screw placement. To address this concern, we measured the proximity of these structures in 7 consecutive fresh-frozen cadaveric knees. For each knee, barium was injected into the femoral artery, and anteroposterior (AP) radiographs were taken to document the location of the popliteal vessels. Next, the initial steps of the Fulkerson osteotomy were performed. Then, a lateral release and the tibial osteotomy were performed, the tubercle was advanced into position, and two 9/64-inch extralong drill bits were placed through the tubercle and the posterior tibial cortex. Repeat AP radiographs were obtained, and digital calipers were used to measure the distance from the drill bits to the popliteal vessels. The vascular structure closest to the exit point of the superior drill bit was the bifurcation of the popliteal artery (mean distance, 8.3 mm; SD, 9.3 mm; range, 0.0-21.3 mm), and in 2 knees this structure directly overlay the bifurcation on the AP radiograph; the vascular structure closest to the exit point of the inferior drill bit was the posterior tibial artery (mean distance, 9.0 mm; SD, 8.0 mm; range, 0.0-20.0 mm), and again in 2 knees the drill bit lay directly over the artery on the AP radiograph. Bicortical drilling for screw placement during the anteromedial tibial tubercle transfer procedure may come precariously close to the posterior vascular structures of the knee, so orthopedic surgeons must take extreme caution not to drill past the posterior cortex during this part of the operation.     

Posterior trans-septal portal for arthroscopic surgery of the knee joint

Summary: The authors introduce a safe arthroscopic technique of making a portal through the posterior septum of the knee joint, posterior to the posterior cruciate ligament (PCL). This posterior trans-septal portal makes it possible for the arthroscope or the working instruments inserted through the posteromedial portal to reach the posterolateral compartment. With this portal, complete arthroscopic visualization of the posterior compartment and easier arthroscopic procedures for the posterior compartment of the knee joints are possible, including the posterior and posterosuperior aspect of the both femoral condyles, the posterior horns of both menisci, the posterior and inferior portion of the PCL, the posterior meniscofemoral ligament, the posterior septum, and the posterior capsule. We have used this technique in more than 150 knees for arthroscopic total synovectomy for arthritis of various origins, arthroscopic PCL reconstructions, arthroscopic removal of encapsulated loose bodies or tumors located behind the PCL, arthroscopic repairs of tears in the posterior horns of the medial menisci using the all-inside technique, arthroscopic pullout suture fixation of the avulsion fracture of tibial attachment of PCL, and others. No complications such as injuries of the popliteal neurovascular structures have occurred in our experience.Arthroscopy: The Journal of Arthroscopic and Related surgery, Vol 16, No 7 (October), 2000: pp 774–779     

股骨单隧道内分叉双束纤维重建后交叉韧带的实验研究

目的在人膝关节标本上行股骨单隧道分叉双束纤维重建后交叉韧带(posterior cruciate ligament,PCL),探讨其术式的优缺点。方法应用力学试验机对14侧捐赠新鲜冷冻人膝关节标本进行生物力学测试,男12侧,女2侧;年龄20～31岁。标本股骨段长20cm,胫骨段长20cm。首先测量PCL完整时胫骨后移距离和交叉韧带的应变(完整组,n=14);然后切断PCL(切断组,n=14),测量胫骨受力时的后移距离后,再将标本随机分为两组:单束重建组(n=7)和分叉双束重建组(n=7),分别测量屈膝0、30、60、90和120°5个角度时胫骨后移距离和移植韧带的应变。结果胫骨受到100N后向力量,完整组在不同屈膝角度下,胫骨向后移位1.97±0.29～2.60±0.23mm,前外束和后内束纤维交替紧张松弛。切断组膝关节明显松弛,胫骨向后移位达11.27±1.06～14.94±0.67mm,与完整组比较差异有统计学意义(P<0.05);单束纤维重建组,在不同屈膝角度下胫骨向后移位1.99±0.19～2.72±0.38mm,移植韧带持续紧张。双束纤维重建组在不同屈膝角度下胫骨向后移位2.27±0.32～3.05±0.44mm,移植的双束纤维交替紧张,协同作用。组内比较:双束重建组在不同屈膝角度时胫骨向后位移差异无统计学意义(P>0.05),而单束重建组在屈膝90°时与屈膝30、60和120°时相比,胫骨后移增大,差异有统计学意义(P<0.05)。结论股骨单隧道内分叉双束纤维重建PCL术在各屈膝角度均能有效防止胫骨后移,股骨单隧道单束重建术屈膝90°时后移较其他角度时增大。分叉双束重建PCL的两束纤维束交替紧张,生物力学特征更接近于正常PCL。     

单隧道免打结锚钉治疗后交叉韧带胫骨止点撕脱骨折

目的总结关节镜下利用单隧道免打结锚钉治疗后交叉韧带(PCL)胫骨止点撕脱骨折的效果。 方法回顾性分析2017年1月至2019年4月淮南朝阳医院骨科收治的PCL胫骨止点撕脱骨折患者,按照纳入排除标准,共纳入36名行关节镜单隧道免打结锚钉内固定治疗的患者。比较每例患者术前及术后6个月的膝关节活动度(ROM)、国际膝关节文献委员会(IKDC)膝关节韧带评估表、Lysholm膝关节功能评分及并发症情况,进行配对立样本t检验。 结果术后6个月随访ROM范围(t＝－22.231)、IKDC评分(t＝－34.958)、Lysholm评分(t＝－40.802)均比术前明显改善(均为P<0.05);所有患者均未出现腘窝神经、血管损伤。 结论采用关节镜下单隧道免打结锚钉内固定技术治疗后交叉韧带胫骨止点撕脱骨折,膝关节功能恢复情况满意。     

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。     

Location of the vertebral artery in the cervicothoracic junction

Eight sectioned specimens and 8 cadavers were used to evaluate the location of the vertebral artery in the cervicothoracic junction. The results of the measurements showed that there was no significant difference between either sides at the C7-T1 junction in terms of all distances taken. The mean width of the vertebral artery was 2.9 mm at the levels of the C-7 and T-1. The sagittal distance between the vertebral artery and the posterior cortex was 16.8+/-3.0 mm at the C7 and 21.7+/-2.8 mm at T-1. The coronal distance between the vertebral artery and the midline of the vertebra was 17.5+/-1.8 mm at the C7 and 22.3+/-2.9 mm at the T-1. The mean angle between the line connecting the lateral border of the vertebral artery with the posterior midway of the lateral mass and the parasagittal line at C-7 was 14.1+/-6.1 degrees. The mean angle of the vertebral artery with respect to the midline was 22.8+/-6.4 degrees. This study suggests that the vertebral artery has closer anatomic relationship to the C-7 lateral mass. Care should be taken to avoid injury to the vertebral artery if lateral mass screw fixation at the C-7 is intended.     

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.     

The Intact Posterior Cruciate Ligament Not Only Controls Posterior Displacement but Also Maintains the Flexion Gap

Background

The PCL is a strong stabilizer of the knee and provides posterior stability to the tibia. However, sagittal alignment of the PCL with the knee at 90° flexion suggests the PCL might play a role not only in posterior stabilization but also in maintaining the flexion gap.

Questions/purposes

We determined whether the intact PCL helps maintain the flexion gap.

Methods

We examined axial radiographs and gravity sag views of 17 patients with chronic isolated unilateral PCL injury. The flexion gap was defined as the mean value of the medial and lateral distances between the femoral and tibial bones on the axial radiograph. Increase in the flexion gap and posterior laxity were determined by comparing the patients’ injured and contralateral uninjured knees.

Results

The flexion gap of PCL injured knees (median, 7.5 mm; range, 5.3–11.5 mm; medial median, 6.2 mm; medial range, 3.7–8.3 mm; lateral median, 7.9 mm; lateral range, 5.3–11.5 mm) was larger than that seen in uninjured knees (median, 5.0 mm; range, 4.0–7.6 mm; medial median, 4.6 mm; medial range 3.4–7.1 mm; lateral median, 5.6; lateral range, 4.5–11.2 mm). The increment in the medial distance was similar to that in the lateral distance. Posterior laxity of injured knees was 9.1 (median); 5.4 to 15.2 (range) mm greater than that of uninjured knees. We found no correlation between posterior laxity and the flexion gap increment.

Conclusions

Our data suggest the intact PCL controls posterior displacement and maintains the flexion gap.     

关节镜下应用异体跟腱股骨双束双隧道同时重建后交叉与前交叉韧带

目的 评价关节镜下应用异体跟腱股骨双束双隧道同时重建后交叉韧带与前交叉韧带的临床疗效.方法 14例前、后交叉韧带损伤患者在关节镜下应用异体跟腱同时重建前、后交叉韧带,且后交叉韧带股骨侧应用双束双隧道重建.受伤至手术时间平均19.5 d.术后平均随访34.5个月.采用Lysholm评分和Tegner评分对患膝功能进行评估,通过KT-1000检查膝关节的前后松弛度.术前患者屈膝活动度(123.6±2.5)°,Lysholm评分(52.8±2.2)分,伤前Tegner评分平均为(5.9±0.5)分,术前为(1.2±0.9)分.结果 术后患者屈膝活动度(117.9±2.8)°,与术前比较差异无统计学意义(t=1.54,P=0.14).术后Lachman试验阴性者13例(92.9%),后抽屉试验阴性者12例(85.7%).KT-1000屈膝25°双侧胫骨前后松弛度差值在2 mm以内9例,3～5 mm 4例,6 mm1例.屈膝70°差值2 mm以内10例,3～5 mm 3例,6 mm 1例.Lysholm评分术后提高至(92.9±3.3)分,差异具有统计学意义(t=17.009,P＜0.001).术后Tegner评分终末随访时平均为(5.4±0.8)分.手术前后的差异有统计学意义(F=4.2,P＜0.01).11例恢复到受伤前运动水平(78.6%),另外3例运动水平较受伤前有所降低.结论 关节镜下应用异体跟腱股骨双束双隧道同时重建后交叉韧带与前交叉韧带,后交叉韧带股骨侧应用双束双隧道重建,更接近后交叉韧带解剖重建,能够恢复膝关节的稳定性,较满意地恢复膝关节功能.     

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.     

Multiple-ligament injured knee

Objective: To explore the clinical characteristic of the multiple-ligament injured knee and evaluate the protocol, technique and outcome of treatment for the multipleligament injured knee. Methods: From October 2001 to March 2005, 9 knees with combined anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears in 9 patients were identified with clinical and arthroscopic examinations. Of them, 5 knees were combined with ruptures of posteromedial corner (PMC) and medial collateral ligament (MCL), 4 with disruptions of posterolateral corner (PLC), 2 with popliteal vascular injuries and 1 with peroneal nerve injuries. Six patients were hospitalized in acute phase of trauma,2 received repairs of popliteal artery and 4 had repairs of PMC and MCL. Reconstructions of ACL and PCL with autografts under arthroscope were performed in all patients at 4 to 10 weeks after trauma, including reconstruction of PLC with the posterior half of biceps femoris tendon tenodesis in 4 patients and reconstructions of PMC and MCL with femoral fascia in 1 patient. Results: No severe complications occurred at early stage after operation in the 9 patients. All of them were followed up for 10-39 months with an average of 23. 00 months±9. 46 months. Lysholm score was 70-95 with an average of 85.00±8.29. International Knee Documentation Committee (IKDC) score was from severely abnormal (Grade D) in 9 knees at initial examination to normal (Grade A) in 2 knees, nearly normal (Grade B) in 6 knees and abnormal in 1 knee at the last follow-up. Of the 9 patients, 7 returned to the same activity level before injury and 2 were under the level. Conclusions:The multiple-ligament injured knee with severe instability is usually combined with other important structure damages. Therefore, careful assessment and treatment of the combined injuries are essential. Reconstructions of ACL and PCL under arthroscope, combined with repairs or reconstructions of the extraarticular ligaments simultaneously or in stages, have advantage of minimal trauma in surgery and satisfactory outcome.     

关节镜下保留残端单束重建后交叉韧带疗效观察

目的：观察关节镜下保留残端单束重建后交叉韧带（posterior cruciate ligament, PCL）的临床疗效。方法回顾性分析自2010年1月至2013年1月对18例PCL损伤患者在我院行关节镜下保留残端PCL单束重建术。记录并比较患者的Lysholm和国际膝关节文献委员会膝关节评估表（International Knee Documentation Committee, IKDC）评分。结果本组患者随访时间24~42个月,平均31.2个月。患者均未发生严重并发症。患者膝关节Lysholm评分由术前的（58.4±4.5）分提高到术后的（91.6±3.1）分,差异有统计学意义（P＜0.05）。IKDC评分由术前的（52.1±7.6）分提高到术后的（88.3±6.2）分,差异有统计学意义（P＜0.05）。结论关节镜下保留残端单束重建PCL术后临床疗效良好,功能满意。     

Value of posterior cruciate ligament index in the diagnosis of anterior cruciate ligament injuries

Assessment of the diagnostic value of the posterior cruciate ligament index (PCL index) for injuries of the anterior cruciate ligament (ACL) was done. Magnetic resonance imaging (MRI) and knee joint arthroscopy of 170 patients were evaluated. The shortest distance between the femoral and tibial attachment of PCL (x) and the distance from that line to the tip of the arc marked by the PCL (y) on the sagittal plane images were measured. The quotient of these two parameters (x/y) defined the PCL index. In 100 patients, for whom arthroscopy ruled out ACL injury, the mean PCL index was 5.01 +/– 0.76. In 30 patients in whom arthroscopy showed total ACL rupture, the mean PCL index was 2.88 +/– 0.74, and in 10 patients with ACL partial rupture, 3.09 +/– 0.23. The conclusion is that injury to the ACL changes the PCL index markedly. In diagnostically unreliable MR images, deterioration of the PCL index could help in the diagnosis of ACL injury. Received: 19 July 1996