骶结节韧带和骶棘韧带的解剖定位研究

目的通过测量骶结节和骶棘韧带附着处附近的骨性标志间的距离,获得两条韧带的解剖定位方法及其体表投影位置,为临床相关应用提供解剖学依据。方法 20例(男、女性各10例20侧)正常成人防腐骨盆标本,用游标卡尺测量同侧髂后上棘至坐骨结节、髂后上棘至坐骨棘、髂后上棘至第4骶椎横突结节、髂后上棘至骶角、坐骨结节至坐骨棘、坐骨棘至骶角、坐骨结节至骶角的距离,并进行性别比较。结果男、女性骨盆髂后上棘至坐骨结节距离分别为(12.19±0.49)cm和(11.20±0.39)cm(P0.05);髂后上棘至骶角距离(7.62±0.50)cm和(6.70±0.92)cm(P0.05)。骶结节韧带的体表投影线为同侧髂后上棘至骶角连线中点与坐骨结节的连线;骶棘韧带的体表投影线为同侧髂后上棘至坐骨结节连线的上3/4与下1/4交点(坐骨棘位置,约距髂后上棘8.5cm)与骶角的连线。结论本研究不仅丰富了人类学数据,且提供的体表定位方法,为临床相关应用和康复治疗提供解剖学参考。     

Anatomical comparison of sciatic nerves between adults and newborns: clinical implications for ultrasound guided block

The sciatic nerve (SN) is easily blocked under ultrasound guidance by identifying either the SN common trunk or its two components: the tibial nerve (TN) and the common peroneal nerve (CPN). The authors investigate whether there are anatomical differences between newborns and adults. The SN, TN and CPN of both lower extremities in 24 (11 neonatal and 13 adults) formolized cadavers were dissected. Distances were measured from the origin of the SN (passing under the piriformis muscle) to its division into TN and CPN, and from there to the popliteal crease. The sciatic/thigh coefficient (proportion relating SN length to thigh length) and the variation coefficient for the SN were calculated. The distance from the popliteal crease to the SN division was significantly shorter in neonates than in adults (1.04 ± 0.9 cm vs. 5.6 ± 5.1 cm, P = 0.0003). In addition, the neonatal SN divided at a proportionally more distal position in the thigh than it did in adults (86 ± 13 vs. 74 ± 15%, P = 0.0059). However, the coefficient of variation between the SN‐division distances was not statistically different in infants and adults (12.8 vs. 18.2%, P = 0.4345). The variations in the point of SN division seen in the adult SN are already seen in the neonatal period, but in newborns the SN divided in a more distal position in relation to the thigh than in adults, so this finding of anatomical variability in neonates suggests that ultrasound guidance can be useful when performing a SN block in these small patients.     

In-vitro validation of a non-invasive dual fluoroscopic imaging technique for measurement of the hip kinematics

Measurement of accurate in vivo hip joint kinematics in 6-DOF is difficult. Few studies have reported non-invasive measurements of the hip kinematics. The objective of this study was to validate a non-invasive dual fluoroscopic imaging system (DFIS) for measurement of hip kinematics. Bi-lateral hip joints of a cadaveric pelvic specimen were CT scanned to create bone models of the femur and pelvis, and subsequently tested in static and dynamic conditions inside the DFIS. The poses of the hip in space were then determined by matching the bone models with the fluoroscopic images. The pose data was compared to those obtained using a radio-stereometric analysis to determine the accuracy of the DFIS. The accuracy ± precision for measuring the hip kinematics were less than 0.93 ± 1.13 mm for translations and 0.59 ± 0.82° for rotations in all conditions. The repeatability of the DFIS technique was less than ±0.77 mm and ±0.64° in position and orientation for measuring hip kinematics in both static and dynamic positions. This technique could thus be a promising tool for determining 6-DOF poses of the hip during functional activities, which may help to understand biomechanical factors in hip pathologic conditions such as osteoarthritis and femoroacetabular impingement before and after surgical treatment.     

Comparison of two stretching methods and optimization of stretching protocol for the piriformis muscle

Piriformis syndrome is an uncommon diagnosis for a non-discogenic form of sciatica whose treatment has traditionally focused on stretching the piriformis muscle (PiM). Conventional stretches include hip flexion, adduction, and external rotation. Using three-dimensional modeling, we quantified the amount of (PiM) elongation resulting from two conventional stretches and we investigated by use of a computational model alternate stretching protocols that would optimize PiM stretching.Seven subjects underwent three CT scans: one supine, one with hip flexion, adduction, then external rotation (ADD stretch), and one with hip flexion, external rotation, then adduction (ExR stretch). Three-dimensional bone models were constructed from the CT scans. PiM elongation during these stretches, femoral neck inclination, femoral head anteversion, and trochanteric anteversion were measured. A computer program was developed to map PiM length over a range of hip joint positions and was validated against the measured scans.ExR and ADD stretches elongated the PiM similarly by approximately 12%. Femoral head and greater trochanter anteversion influenced PiM elongation. Placing the hip joints in 115° of hip flexion, 40° of external rotation and 25° of adduction or 120° of hip flexion, 50° of external rotation and 30° of adduction increased PiM elongation by 30–40% compared to conventional stretches (15.1 and 15.3% increases in PiM muscle length, respectively).ExR and ADD stretches elongate the PiM similarly and therefore may have similar clinical effectiveness. The optimized stretches led to larger increases in PiM length and may be more easily performed by some patients due to increased hip flexion.     

Piriformis muscle: clinical anatomy and consideration of the piriformis Syndrome

Patients with lumbosacral and buttock pain provide tacit support for recognizing the piriformis muscle as a contributing factor to the pain (piriformis syndrome). One hundred and twelve cadaveric specimens were observed to elucidate the anatomical variations of the piriformis muscle referred to the diagnostic and treatment of the piriformis syndrome. The distance between the musculotendinous junction and the insertion was measured and the piriformis categorized into three types: Type A (71, 63.39%): long upper and short lower muscle belly; Type B (40, 35.71%): short upper and long lower muscle belly; Type C (1, 0.9%): fusion of both muscle bellies at the same level. The diameter of the piriformis tendon at the level of the musculotendinous junction ranged from 3 to 9 mm (mean: 6.3 mm). The piriformis showed the following possible fusions with adjacent tendons. In type one (60, 53.57%) a rounded tendon of the piriformis reached the upper border of the greater trochanter. In type two (33, 29.46%) it first joined into the gemellus superior tendon and at last both fused with the obturator internus tendon and inserted into the medial surface of the greater trochanter. A fusion of the piriformis, obturator internus and gluteus medius tendon with the same insertion area as above was observed in type three (15, 13.39%) and finally in type four (4, 3.57%) the tendon fused with the gluteus medius to reach the upper surface of the greater trochanter. Based on this survey anatomical causes for the piriformis syndrome are rare and a more precise workup is necessary to rule out more common diagnosis.     

A novel anteroposterior axis of the tibia for total knee arthroplasty: An upright weight-bearing computed tomography analysis

BackgroundThe traditional anteroposterior (AP) axis (i.e., Akagi’s line) has been widely used as the tibial component AP axis during total knee arthroplasty (TKA). However, this AP axis has been defined based on computed tomography (CT) in a non-weight-bearing supine position. In this study, AP axes of the tibial plateau from upright CT in weight-bearing and non-weight-bearing positions were determined and compared.MethodsThis study included 43 knees from 23 healthy volunteers. CT images were obtained in weight-bearing and non-weight-bearing standing positions using a 320-detector row upright CT scanner. The line perpendicular to surgical transepicondylar axis projected onto the tibia plateau was determined as the AP axis in upright weight-bearing and non-weight-bearing conditions. Angular differences between these two conditions were measured.ResultsThe upright weight-bearing AP axis was positioned in a mean of 7.4 ± 4.3° of internal rotation relative to the traditional AP axis. Distance between the traditional and upright weight-bearing AP axis was 2.9 ± 1.6 mm at the edge of the tibial plateau. The upright non-weight-bearing AP axis was positioned in a mean of 3.5 ± 4.1° of internal rotation relative to the traditional AP axis. Mean angular difference between weight-bearing and non-weight-bearing conditions was 3.9 ± 4.1°.ConclusionsThe upright weight-bearing AP axis was positioned in 7.4° of internal rotation relative to the traditional AP axis, showing one-seventh of the tibial tuberosity away from the medial border of the tibial tubercle, which represents a practical landmark for the tibial component AP axis during TKA.     

Three-dimensional morphology of the distal femur based on surgical epicondylar axis in the normal elderly population

BackgroundWe aimed to analyze the surface morphology of the distal femur in three dimensions for the healthy elderly, based on the concept that the surgical epicondylar axis (SEA) is a better surrogate for the flexion–extension axis of the knee joint.MethodsWe studied 77 healthy elderly volunteers (40 males and 37 females; age, 68 ± 6 years). The medial and lateral contact lines were calculated three-dimensionally, using the highest points of the medial and lateral condyles in 201 cross-sectional planes around the SEA (every 1°, −60° (hyperextension) to 140° (flexion)). A piecewise fitting function consisting of two linear segments was applied to detect the inflection point of the constant radii in the sagittal plane. The main assessment parameters were knee flexion angle at the inflection point of the radius (inflection angle), mean radius from 0° to the inflection angle (constant radius), and coronal tilt angle of the contact line.ResultsThe inflection angles, constant radii, and coronal tilt angles were 78.2 ± 8.6°, 26.1 ± 2.3 mm, and −0.6 ± 3.2° and 65.6 ± 9.2°, 23.9 ± 2.2 mm, and 6.2 ± 3.2° in the medial and lateral condyles, respectively (all, P < 0.001). The coronal alignment was 88.7 ± 2.2°.ConclusionsThe medial and lateral femoral condyles showed asymmetrical morphologies with the almost ‘constant’ radius of sagittal curvature from 0° to around 80° and 65° of knee flexion, respectively.     

Kinematics of the lumbar spine in elderly subjects with decreased bone mineral density

Lumbar spine kinematics was studied in subjects with normal bone mineral density, osteopenia and osteoporosis to determine the effect of bone mineral density and morphology on the flexion–extension movement patterns of the lumbar spine. Lateral radiographs and skin-mounted electromagnetic motion tracking sensors were employed to study lumbar spine kinematics using a Bayesian Belief Network model. The predicted angular displacement of the vertebrae had a high correlation (r = 0.91, p < 0.001) with the actual movements. The overall mean error was −0.51° ± 3.11°. Intervertebral angular displacement and velocity consistently increased from L1/L2 to L5/S1. Differences were observed in the movement pattern between normal subjects and those with decreased bone density. In normal subjects, vertebral angular acceleration consistently decreased from the upper to the lower vertebrae but the same consistent predictable pattern was not observed in the subjects with decreased bone mineral density. It is possible that these changes in kinematic behaviours are related to morphological changes as well as altered neuromuscular functions.     

Knee kinematics after cruciate retaining highly congruent mobile bearing total knee arthroplasty: An in vivo dynamic RSA study

PurposeThis work presents a kinematic evaluation of a cruciate retaining highly congruent mobile bearing total knee arthroplasty design using dynamic Roentgen sterephotogrammetric analysis. The aim was to understand the effect of this implant design on the kinematics of prosthetic knees during dynamic activities.MethodsA cohort of 15 patients was evaluated at nine month follow-up after surgery. The mean age was 74.8 (range 66–85) years.The kinematics was evaluated using the Grood and Suntay decomposition and the Low-Point (LP) methods.Results?tlsb=-0.15pt?>From sitting to standing up position, the femoral component internally rotated (from − 11.3 ± 0.2° to − 7.0 ± 0.2°). Varus–valgus rotations were very close to 0° during the whole motor task.LP of medial condyle moved from an anterior position of 12.0 ± 0.2 mm to a posterior position of − 12.4 ± 0.2 mm; LP of the lateral condyle moved from an anterior position of 8.1 ± 0.2 mm to a posterior position of − 12.4 ± 0.2 mm, showing a bi-condylar rollback where both condyles moved parallel backward. Moreover, the femoral component showed anterior translation with respect to the tibia from 80° to 20° (from − 4.9 ± 0.2 mm to 3.3 ± 0.2 mm), then a posterior translation from 20° to full extension was identified (from 3.3 ± 0.2 mm to 0.5 ± 0.2 mm).ConclusionsParadoxical anterior femoral translation and absence of medial-pivoting motion were recorded, highlighting the role of the symmetric deep dishes insert as main driver of the kinematic of this TKA design.     

Patello-femoral contact area and compressive force after anteromedial displacement of tibial tuberosity in amputated knees

Contact force and contact area in the patello-femoral joint was biomechanically analyzed using seven amputated legs. The knees were fixed firmly to the experimental apparatus and 300 N of tension was applied to the quadriceps tendon. Total contact force was measured using pressure-sensitive film, and the ratio of the contact area to the patellar joint surface (%) was measured using hydrophilic vinyl polysiloxane impression material. At a Q-angle of 0° with no advancement, 10 mm and 20 mm advancement of the tibial tuberosity, the total contact force on the patello-femoral joint at a knee flexion of 45° was 266±55 N, 191±58 N and 146±58 N, respectively. The total contact force became smaller as the advancement of the tibial tuberosity changed to 5, 10, 15 and 20 mm. Especially, the total contact force with Q-angle of 0° and anterior advancement of 15 and 20 mm was significantly smaller than that with no advancement. With a Q-angle of 0°, the contact area of the patello-femoral joint at 10 mm advancement was the greatest, occupying 30.1±9.9% of the whole patellar joint surface. The mean contact pressure with Q-angle of 0° and anterior advancement of 10 mm was smaller than that with all other positions, but there was no significant difference. In this experiment, combined anterior and medial displacement of the tibial tuberosity reduced the contact force in the patello-femoral joint of the amputated legs, and an advancement of 10 mm achieved optimal reduction of force and the greatest contact area.     

Anatomical relation between sciatic nerve and piriformis muscle and its bifurcation level during fetal period in human

Purpose

The aim of this study is to determine the morphometric development, location and variant formations of the sciatic nerve using anatomic dissection method during the fetal period.

Methods

Sciatic nerves of 200 human fetuses (103 males and 97 females) aged between 9 and 40 weeks of gestation were studied bilaterally. The bifurcation level of the sciatic nerve to its terminal branches was evaluated with respect to popliteal fossa. Then the length of the sciatic nerve, starting from where it leaves the piriformis muscle till the bifurcation point of the nerve, and its width at the point where it leaves infrapiriforme foramen and its width at the bifurcation level were measured. We also measured the distance of the sciatic nerve to the ischial tuberosity, the greater trochanter and the intergluteal sulcus. Mean values and standard deviations of all parameters according to trimesters were calculated.

Results

We found that all parameters increase with age during the fetal period (P < 0.05). Parameters do not show any significant differences between sexes (P > 0.05). In our analysis, we observed that in 98 % of the cases (on the right and the left side) the sciatic nerve leaves the pelvis below the piriformis muscle. The remaining cases (2 %) are variant formations.

Conclusion

We believe that our study will be useful for better understanding of sciatic nerve development and it may contribute to future studies in obstetrics, orthopedics and fetal pathology. Knowledge of variant formations of the sciatic nerve, its bifurcation level and its relation with neighboring structures may be important for blockade of the nerve in newborn surgeries.     

Surgical landmarks of the ureter in the cadaveric female pelvis

Our purpose was to delineate the course of the ureter in the female pelvis in relationship to several important surgical landmarks. Ten female cadavers with undissected pelves were used. The ureter was identified at the pelvic brim and traced inferiorly to the bladder. Sets of measurements (±0.1 cm) that help define the location of the ureter were obtained at the three landmarks; the ischial spine, the obturator canal and the insertion of the arcus tendineus on the pubic bone. The mean distances from the ureter to the pelvic floor were ischial spine, 3.2 ± 0.1 cm; obturator canal, 3.2 ± 0.1 cm; and the insertion of the arcus tendineus on the pubic bone, 1.6 ± 0.1 cm. The mean distances from the arcus tendineus to the pelvic floor were ischial spine, 1.9 ± 0.1 cm; obturator canal, 2.8 ± 0.1 cm; and the insertion of the arcus tendineus on the pubic bone, 3.2 ± 0.1 cm. This study defines the relationship of the ureter to the pelvic floor through measurements taken at three landmarks. The data should be useful to pelvic surgeons and are important for the development of future surgical techniques. Clin. Anat. 10:324–327, 1997. © 1997 Wiley-Liss, Inc.     

Morphological measurements of the posterior surface of the normal proximal tibia in a healthy Chinese population

BackgroundTo measure and calculate the morphological parameters and determine the anatomical characteristics of the posterior surface of the proximal tibia in a healthy Chinese population.MethodsA total of 150 volunteers with normal knees were enrolled. The parameters in the multi-slice spiral computed tomography (MSCT) three-dimensional (3-D) reconstruction images were measured and calculated by two independent qualified observers. The differences and correlation were investigated. The intraclass correlation coefficient (ICC) was used to assess inter-observer reliability.ResultsThe posterior margin of the tibial plateau is presented as two superior arc-shapes. The central angles of these arcs were 118° ± 14° (medial) and 106° ± 20° (lateral). The radii of these arcs both showed a skewed distribution. The median radii of the arcs were 22 mm in the medial and 20 mm in the lateral. There were two significant angles present in the sagittal plane of the posterior cortex of the proximal tibia. The first angles were 39° ± 7° (medial) and 47° ± 7° (lateral). The second angles were 39° ± 4° (medial) and 41° ± 5° (lateral). Significant differences were observed in the central angles and the first angles but not in the second angles between the medial and lateral. There were no significant differences between different gender groups, and between left and right limbs. All of these parameters exhibited excellent to moderate ICC.ConclusionDue to the varying anatomic morphology between the postero-medial and postero-lateral surface of the proximal tibia, the internal fixation implants of these two parts should be designed differently.     

Quantified relationships of the radial nerve with the radial groove and selected humeral landmarks

Anatomical relationships between the radial nerve, the deltoid muscle insertions and several bony landmarks have been investigated to assess the feasibility of surgical transfer of the deltoid transfer during humeral osteotomy. Eleven embalmed human specimens were dissected. Each specimen included the whole thorax, both shoulders and upper limbs. Spatial position of the radial nerve along the radial groove, the deltoid muscle, and several anatomical landmarks was digitised using a three-dimensional (3D) digitiser. Sixteen distances and one angle characterizing the relationships between the path of the radial nerve and the landmarks were processed. Results showed that the average distance between the emergence of the radial nerve from the lateral intermuscular septum and the most distal insertion point of the deltoid muscle on the humeral bone shaft was 47.6 ± 18.5 mm. The angle between a line extending from the entry of the radial nerve into the radial sulcus and its point of emergence (REN–REM line), and on the other hand a line running from the radial emergence and the deltoid muscle tip (REM–DELTIP line) was in average 23.5 ± 6.7°. The length of four lines running perpendicular to REM–DELTIP and crossing each quarter of the REN–REM line were interpolated. The length of these four lines was, from proximal to distal, 31.3 ± 11.5 mm; 23.0 ± 7.8 mm; 16.5 ± 6.2 mm; and 7.6 ± 2.6 mm, respectively. These results described in a quantitative way the path of the radial nerve in respect to the humeral bone and the deltoid muscle. These data will be used for further development of a humeral osteotomy protocol taking into account the spatial position of the radial nerve to orientate safely the surgical tools used to cut the humeral shaft.     

逆行经皮髋臼后柱螺钉的影像解剖学

目的 探讨逆行髋臼后柱螺钉的进钉位置、方向及固定范围。方法 收集100例正常成人骨盆CT数据（男、女各50例）,利用交互式医学图像控制系统（Mimics）17.0软件三维重建骨盆并导入Geomagic Studio 2015软件。从坐骨结节至髂窝方向进行透视,垂直后柱“三棱柱”通道横断面放置虚拟螺钉,测量螺钉的最大直径、进钉点、方向、出钉点及螺钉安全倾角。确定螺钉固定的范围,螺钉在后柱通道易穿出部位及术中判断螺钉是否穿出的透视体位。结果 髋臼后柱安全通道近似“三棱柱”形,进钉点位于坐骨结节内外侧缘中线上,距离坐骨结节最远端男性为(12.99±1.99) mm,女性为 (13.26±2.58) mm,男女差异无显著性 (P＞0.05);髂窝出钉点距离同侧前方骶髂关节线男性为(23.65±2.42)mm,女性为(24.94±2.39) mm;距离真骨盆缘男性为(19.33±2.60)mm,女性为(17.63±2.00) mm;最大螺钉直径男性为(17.21±1.41) mm,女性为(15.54±1.51) mm;髋臼后柱逆行置钉方向与矢状面夹角男性为(10.52±3.04)°,女性为(7.72±2.99)°;与冠状面夹角男性为(15.00±4.92) °,女性为 (12.94±4.72)°,以上数据男女间差异均有显著性（P＜0.05）。逆行经坐骨结节置钉可固定股骨头中心所在水平面近端 4 cm 以下所有的髋臼后柱骨折,易穿出部位分别为髋臼后壁与坐骨支移行处、髋臼中部、坐骨大切迹水平下1 cm。“三棱柱”的3个侧面的切线位分别是髂骨斜位10°,闭孔斜位60°,髂骨斜位60°。结论 逆行髋臼后柱螺钉进钉点位于坐骨结节内外侧缘中线,距离坐骨结节最远端1.3 cm,方向约外倾10°,前倾15°,可固定股骨头中心所在水平面近端4 cm以下的髋臼后柱骨折。     

内镜引导下经后路上颈椎螺钉内固定的应用解剖

目的探讨内镜引导下经后路上颈椎螺钉内固定的应用解剖,为临床经后路C2/3椎弓根螺钉固定术提供解剖学资料。方法选用干骨28套(C1-7),对其滋养孔的位置、椎弓根等相关数据进行了观察和测量。结果C2/3的滋养孔距后正中线分别为(17.26±7.36)和(16.05±7.95)mm;椎弓根的长、高、宽(mm)分别为6.18±1.36、8.87±2.22、11.54±3.21和4.95±3.5、7.00±0.97、10.50±4.11;椎弓根的中轴线与正中矢状切面所构成的夹角分别为(43.83±3.09)°和(41.53±3.29)°。结论临床经后路C2/3椎弓根螺钉内固定手术,进螺点可选定在C2/3侧块距其外侧缘5mm、距下关节突下缘8mm处,螺钉进入的延长线与正中矢状切面的夹角应为40°～45°,并向头侧倾斜10°为宜,螺钉的长度为24～30mm,覬为5mm为佳。     

Three-dimensional assessment of lower limb alignment: Reference values and sex-related differences

BackgroundThree-dimensional (3D) preoperative planning and assisted surgery is increasingly popular in deformity surgery and arthroplasty. Reference ranges for 3D lower limb alignment are needed as a prerequisite for standardized analysis of alignment and preoperative planning in 3D, but are not yet established.MethodsOn 60 3D bone models of the lower limbs based on computed tomography data, fifteen parameters per leg were assessed by standardized validated 3D analysis. Distribution parameters and differences between sexes were evaluated. Reference values were generated by adding/subtracting one standard deviation from the mean.ResultsWomen had a significantly lower mean mechanical lateral distal femoral angle compared with men (86.4 ± 2.1° vs. 87.8 ± 2.0°; P < .05) and significantly lower mean joint line convergence angle (−2.5 ± 1.4° vs. -1.3 ± 1.2; P < .01), but higher mean hip knee ankle angle (178.9 ± 1.9° vs. 177.8 ± 2.3°; P < .05) and mean femoral torsion (18.2 ± 9.5° vs. 13.2 ± 6.4°; P < .05), resulting in a tendency towards valgus alignment and vice versa for men. Differences in mean medial proximal tibial angle were not significant. The mean mechanical axis deviation from the tibial knee joint center was 6.9 ± 7.3 mm medial and 1.4 ± 16.1 mm ventral without significant differences between sexes.ConclusionsWe describe total and sex-related reference ranges for all alignment relevant axes and joint angles of the lower limb. There are sex-related differences in certain alignment parameters, which should be considered in analysis and surgical planning.     

经皮穿刺胸腺的应用解剖

目的通过穿刺胸腺组织诊断胸腺肿瘤,注入抗肿瘤药物治疗重症肌无力等。方法解剖观察成尸标本37具,观测胸腺的位置、形态,经皮穿刺进针点及深距。结果胸腺位于胸骨后方长(88.3±21.8)mm,宽(32.3±10.5)mm,厚(5.1±2.3)mm。经皮从胸骨柄上缘颈静脉切迹穿刺点穿刺至胸骨角后方深距(62.8±14.1)mm。从胸锁乳突肌内侧下段穿刺点至胸骨柄后方深距(45.0±9.2)mm,向前内进针角度为17.7°±7.9°。结论可经皮穿刺胸腺组织诊断胸腺增生或肿瘤,介入注射抗肿瘤药物治疗重症肌无力等。     

Characterization of the orientation and isometry of Humphrey's ligament

Objectives/purposeThe purpose of this study was to examine the effect of flexion angle on isometry and fiber obliquity of the anterior meniscofemoral ligament (Humphrey's ligament (HL)).MethodsFollowing a medial parapatellar arthrotomy on 7 fresh frozen cadavers, the insertion points of the anterolateral (AL) and posteromedial (PM) bundles of the PCL, and HL were identified. Using a 9 mm circular software tool, virtual fibers were created. Within each virtual graft, a central fiber was calculated and used to generate anisometry profiles for the AL and PM bundles and HL at flexion angles of 0°, 30°, 60°, 90°, and 120°. Previously validated computer navigation software was used to re-create three dimensional bundles to measure fiber obliquity in the sagittal, frontal, and axial planes.ResultsHL length increased with knee flexion from 0 to 120°, and underwent similar length changes as the PCL bundles. In full extension and at 90°, the average length of the PM and AL bundles were not statistically different (p = 0.13 and p = 0.85 respectively). From 0 to 120°, the PM bundle was the most isometric, but the anisometry profile was statistically similar to the AL bundle and HL. In general, HL and the PM bundle had similar graphic trends in terms of fiber obliquity in all planes.ConclusionsUsing computer navigation, we have demonstrated that HL has similar isometry profiles as the PM and AL bundles of the PCL, and “mirrored” the obliquity of the PM bundle in all planes throughout flexion to 120°.