Attachment Of Posterior Cruciate Ligament Research Articles

Inflating a thigh tourniquet anteriorly displaces the popliteal artery relative to the posterior tibial cortex: an in vivo magnetic resonance imaging study

Background Previous work has demonstrated that with increasing knee flexion angles, the popliteal artery is located further away from the posterior tibial cortex (PTC), thus offering a safer position for procedures about the knee. Prior studies did not, however, incorporate the use of a surgical thigh tourniquet, a device commonly used by orthopaedic surgeons. Thigh tourniquet effect on popliteal spatial anatomy will be assessed in this study. Methods Using 3 Tesla magnetic resonance imaging, 6 volunteer knees were evaluated in both full extension and 90 degrees (°) of flexion, with and without a thigh tourniquet inflated to 200 millimeters of mercury. Axial images at the level of the posterior cruciate ligament (PCL) tibial insertion were obtained. The distance of the popliteal artery from the PCL tibial insertion and the PTC at this level were calculated. Results Without a tourniquet, at 0° and 90° of flexion, the mean distance between the popliteal artery and the PTC was 6.9 and 9.4 millimeters, respectively. With a tourniquet, at 0° and 90° the mean distance between the popliteal artery and the PTC decreased to 6.2 (-0.7) and 8 (-1.4) millimeters, respectively. These reductions in distances with inflating the tourniquet were statistically significant (p<0.05). The distance between the artery and the PCL attachment did not change with and without inflating the tourniquet. Conclusions Inflating a thigh tourniquet moves the popliteal artery approximately 1 millimeter (8.5 percent) anterior towards the PTC and has no effect on the relationship between the popliteal artery and PCL insertion.

Posterior Cruciate Ligament Reconstruction Using Flat Soft-Tissue Grafts

Isolated posterior cruciate ligament (PCL) ruptures are relatively rare, but they more commonly occur in multiligament knee injuries. To date, in isolated or combined injuries with grade III step-off, surgical treatment is recommended to restore joint stability and improve knee function. Several techniques for PCL reconstruction have been described. However, recent evidence has suggested that broad, flat soft-tissue grafts may more closely mimic the native PCL ribbonlike morphology in PCL reconstruction. Furthermore, a femoral rectangular bone tunnel may more accurately re-create the native PCL attachment, allowing grafts to simulate native PCL rotation during knee flexion and potentially improving biomechanics. Therefore, we have developed a PCL reconstruction technique using flat quadriceps or hamstring grafts. This technique can be performed using 2 types of surgical instruments that allow for the creation of a rectangular femoral bone tunnel.

Application of CT-MRI Fusion-Based Three-Dimensional Reconstruction Technique in the Anatomic Study of Posterior Cruciate Ligament.

During PCL reconstruction surgery, precise and personalized positioning of the graft tunnel is very important. In order to obtain patient-specific anatomical data, we established a three-dimensional knee joint fusion model to provide a unified imaging strategy, as well as anatomical information, for individualized and accurate posterior cruciate ligament (PCL) reconstruction. This is an exploration study. From January 2019 to January 2020, 20 healthy adults randomly were enrolled and assessed via CT and MRI imaging. A three-dimensional fusion model of the knee joint was generated using the modified MIMIMICS and image fusion software. On the fused image, the areas of the femoral and tibial PCL footprint of both knees were measured. The anatomical center of the PCL footprint was measured at the femoral and tibial ends. The relevant bony landmarks surrounding the PCL femoral and tibial attachment were also measured. Paired t-tests were employed for all statistical analyzes, and p < 0.05 was considered as statistically significant. All 20 subjects achieved successful image fusion modeling and measurement, with an average duration of 12h. The lengths of the LF1-LF3 were 32.1 ± 1.8, 6.8 ± 2.5, and 23.3 ± 2.1 mm, respectively. The lengths of the LT1-LT3 were 37.3 ± 3.3, 45.6 ± 5.3, and 6.0 ± 1.2 mm, respectively. The distances between the tibial PCL center of the left knee to the medial groove, champagne-glass drop-off, and the apex of the medial intercondylar were 8.4 ± 2.4, 9.2 ± 1.8, and 15.3 ± 1.4 mm, respectively, and the corresponding distances from the right knee were 8.0 ± 2.0, 9.4 ± 2.2, and 16.1 ± 1.8 mm, respectively. We observed no difference between the bilateral sides, in terms of the distance from the PCL center to the PCL attachment-related landmark, under arthroscopic guidance. The area of the femoral and tibial PCL footprints on the left knee were 115.3 ± 33.5 and 146.6 ± 24.4 mm2 , respectively, and the corresponding areas on the right knee were 121.8 ± 35.6 and 142.8 ± 19.5 mm2 , respectively. There was no difference between the bilateral sides in terms of the PCL footprint areas. In the fusion image, the PCL attachment center and relevant bony landmarks which can be easily identified under arthroscopy can be accurately measured. The model can also obtain personalized anatomical data of the PCL on the unaffected side of the patient, which can guide clinical PCL reconstruction.

3D Killer Turn Angle in Transtibial Posterior Cruciate Ligament Reconstruction Is Determined by the Graft Turning Angle both in the Sagittal and Coronal Planes.

ObjectiveDuring the transtibial posterior cruciate ligament (PCL) reconstruction, surgeons commonly pay more attention to the graft turning angle in the sagittal plane (GASP), but the graft turning angle in the coronal plane (GACP) is always neglected. This study hypothesized that the three‐dimensional (3D) killer turn angle was determined by both the GASP and GACP, and aimed to quantitively analyze the effects of the GASP and GACP on the 3D killer turn angle.MethodsThis was an in‐vitro computer simulation study of transtibial PCL reconstruction using 3D knee models. Patients with knee injuries who were CT scanned were selected from the CT database (April 2019 to January 2021) at a local hospital for reviewing. A total of 60 3D knees were simulated based on the knees' CT data. The femoral and tibial PCL attachment were located on the 3D knee model using the Rhinoceros software. The tibial tunnels were simulated based on different GASP and GACP. The effects of the GASP and GACP on the 3D killer turn angle were quantitatively analyzed. One‐way analysis of variance was used to compare the outcomes in different groups. The regression analysis was performed to identify variables of the GASP and GACP which significantly affected 3D killer turn angle.ResultsThe 3D killer turn angle showed a significant proportional relationship not only with the GASP (r 2 > 0.868, P < 0.001), but also with the GACP (r 2 > 0.467, P < 0.001). Every 10° change of the GACP caused 2.8° to 4.4° change of the 3D killer turn angle, whereas every 10° change of the GASP caused 6.4° to 9.2° change of the 3D killer turn angle.ConclusionsThe 3D killer turn angle was significantly affected by both the GASP and GACP. During the transtibial PCL reconstruction, the proximal anterolateral tibial tunnel approach could increase the 3D killer turn angle more obviously compared with the most distal anteromedial tibial tunnel approach. To minimize the killer turn effect, both the GASP and GACP were required to be considered to increase.

Isolated avulsion fracture of the tibia at the insertion to the posterior cruciate ligament

Three cases of evulsion tibia fractures at the posterior cruciate ligament attachment are presented. The bone fragment displacement was more than 1 cm. All patients were treated surgically. In 1 patient reduction offracture was completed by bone suture, in 2 patients by fixation with screw inserted retrogradely. Follow up from 6 months to 4 years showed no complications, the joint was stable and full volume of motion was noted.

Post-operative Physiotherapeutic Rehabilitation in a Rare Case of Avulsion Fracture of Tibial Attachment of Posterior Cruciate Ligament: A Case Report

Avulsion fractures of tibial attachment of PCL are not observed very often. PCL injuries are uncommon; especially those involving tibial aspect/fragment are rare. On the basis of the site of damage: Hyperflexion, Hyperextension, Pretibial trauma, etc. are the considered causes of injury. Injury to the PCL results changes in the kinematics of the knee. Changes in contact pressure have been demonstrated in both the patellofemoral and the medial tibiofemoral compartments after sectioning of the PCL, with significant increase in joint forces. This alteration in the normal kinematics may explain the tendency for the development of degenerative changes in the above mentioned compartments after PCL injury. Physiotherapy plays a very vital role in the treatment and management of such cases. Here, we report a case of a 25year old young man who was admitted to Acharya Vinobha Bhave Rural Hospital (AVBRH), Datta Meghe Institute of Medical Sciences (DMIMS), Deemed to be University (DU), with an alleged history of slip and fall from two-wheeler due to RTA sustaining injury to the right limb, particularly on the knee and further complained of pain &amp; swelling over the knee along with difficulty in walking. On examination and investigation it was diagnosed as the case of avulsion fracture of tibial attachment of PCL. And so was operated and treated with open reduction and internal fixation (ORIF). Thereafter, was referred to the Physiotherapy Department for further rehabilitation. The purpose of this study is to: Discuss the epidemiology&amp; Operative method. Discuss the physiotherapeutic management and rehabilitation of PCL tears and their outcomes.

Dynamic Three-Dimensional Computed Tomography Mapping of Isometric Posterior Cruciate Ligament Attachment Sites on the Tibia and Femur: Single- Versus Double-Bundle Analysis

(1) To determine the area of posterior cruciate ligament (PCL) insertion sites on the lateral wall of the medial femoral condyle (LWMFC) that demonstrates the least amount of length change through full range of motion (ROM) and(2) to identify a range of flexion that would be favorable for graft tensioning for single-bundle (SB) and double-bundle (DB) PCL reconstruction. Six fresh-frozen cadaveric knees were obtained. Three-dimensional computed tomography point-cloud models were obtained from 0° to 135°. A point grid was placed on the LWMFC and the tibial PCL facet. Intra-articular length was calculated for each point on the femur to the tibia at all flexion angles and grouped to represent areas for bone tunnels of SB and DB PCLR. Normalized length changes were evaluated. Femoral tunnel location and angle of graft fixation were significant contributors to mean, minimum, and maximum normalized length of the PCL (all p < .001). Tibial tunnel location was not significant in any case (all p < .22). A femoral tunnel in the location of the posteromedial bundle of the PCL resulted in the least length change at all tibial positions (maximum change 13%). Fixation of the anterolateral bundle in extension or at 30° flexion resulted in significant overconstraint of the PCL graft. The femoral tunnel location for a SB PCLR resulted in significant laxity at lower ranges of flexion. PCL length was significantly dependent on femoral tunnel position and angle of fixation, whereas tibial tunnel position did not significantly contribute to observed differences. All PCL grafts demonstrated anisometry, with the anterolateral bundle being more anisometric than the posteromedial bundle. For DB PCLR, the posteromedial bundle demonstrated the highest degree of isometry throughout ROM, although no area of the LWMFC was truly isometric. The anterolateral bundle should be fixed at 90° to avoid overconstraint, and SB PCLR demonstrated significant laxity at lower ranges of flexion. Surgeons can apply the results of this investigation to surgical planning in PCLR to optimize isometry, which may ultimately reduce graft strain and the risk of graft failure. Additionally, DB PCLR demonstrated superiority compared with SB PCLR regarding graft isometry, as significant laxity was encountered at lower ranges of flexion in SB PCLRs. Fixation of the ALB at 90° flexion should be performed to avoid overconstraint in knee extension.

Factors Influencing Graft Function following MPFL Reconstruction: A Dynamic Simulation Study.

Medial patellofemoral ligament (MPFL) reconstruction is currently the primary surgical procedure for treating recurrent lateral patellar instability. The understanding of graft function has largely been based on studies performed with normal knees. The current study was performed to characterize graft function following MPFL reconstruction, focusing on the influence of pathologic anatomy on graft tension, variations with knee flexion, and the influence on patellar tracking. Knee squatting was simulated with 15 multibody dynamic simulation models representing knees being treated for recurrent lateral patellar instability. Squatting was simulated in a preoperative condition and following MPFL reconstruction with a hamstrings tendon graft set to allow 0.5 quadrants of lateral patellar translation with the knee at 30 degrees of flexion. Linear regressions were performed to relate maximum tension in the graft to parameters of knee anatomy. Repeated measures comparisons evaluated variations in patellar tracking at 5-degree increments of knee flexion. Maximum graft tension was significantly correlated with a parameter characterizing lateral position of the tibial tuberosity (maximum lateral tibial tuberosity to posterior cruciate ligament attachment distance, r 2 = 0.73, p < 0.001). No significant correlations were identified for parameters related to trochlear dysplasia (lateral trochlear inclination) or patella alta (Caton-Deschamps index and patellotrochlear index). Graft tension peaked at low flexion angles and was minimal by 30 degrees of flexion. MPFL reconstruction decreased lateral patellar shift (bisect offset index) compared with preoperative tracking at all flexion angles from 0 to 50 degrees of flexion, except 45 degrees. At 0 degrees, the average bisect offset index decreased from 0.81 for the preoperative condition to 0.71. The results indicate that tension within an MPFL graft increases with the lateral position of the tibial tuberosity. The graft tension peaks at low flexion angles and decreases lateral patellar maltracking. The factors that influence graft function following MPFL reconstruction need to be understood to limit patellar maltracking without overloading the graft or over constraining the patella.

Evaluation of the permissible maximum angle of the tibial tunnel in transtibial anatomic posterior cruciate ligament reconstruction by computed tomography.

Excessive angle of the tibial tunnel may cause breakage of the posterior cortex in transtibial anatomic posterior cruciate ligament (PCL) reconstruction. However, a few studies have determined the permissible maximum angle of the tibial tunnel. The purpose of this study was to determine the permissible maximum angle of the tibial tunnel relative to the tibial plateau in transtibial anatomic PCL reconstruction and characterize the anatomic parameters of the tibial PCL attachment position. Computed tomography (CT) scans of a consecutive series of 408 adult knees with normal PCL attachment were measured. The parameters measured were the permissible maximum angle (PMA) of the 10mm-diameter tibial tunnel relative to the tibial plateau, the distance from the anterior orifice of the tibial tunnel to the tibial tuberosity (OTD), the anterior-posterior diameter (APD) of the tibial plateau, the distance from the center of PCL attachment site to the posterior edge of the tibial plateau (PPED), and the angle between the tibial plateau and the posterior tibial slope where the PCL insertion site was (PSA). Subgroup analysis was performed to determine the correlations between parameters, and sex, age, and height. The measurement reliability was evaluated by intraclass correlation coefficients (ICCs). The average value of PMA was 48.2 ± 5.4°, and it was not affected by sex, age, and height (P > 0.05). The values of OTD, APD, PPED, PSA, and height were significantly higher in males than females (OTD, P < 0.01; APD, P < 0.01; PPED, P < 0.01; PSA, P = 0.019; height, P < 0.01). With regard to age, we stratified the cases into three groups: the young (18-30years old), the middle-aged (31-45years old), and the elderly (46-60years old). The mean value of OTD, APD, and height were significantly lower in the elderly than that in the middle-aged (P < 0.01, P < 0.01, P < 0.01, respectively). With regard to height, we stratified the cases into three groups: ~ 1.65m (1), 1.66 ~ 1.75m (2), and 1.76m ~ (3). The mean value of OTD, APD, and PPED significantly increased with height, P < 0.05. The mean value of PSA was significant higher in II group than that in I group (P = 0.034). There should be a limit to the angle of the tibial tunnel in transtibial anatomic PCL reconstruction to prevent the fracture of posterior tunnel wall. The permissible maximum angle (PMA) of the 10mm-diameter tibial tunnel relative to the tibial plateau was 48.2°. Besides, the determination of the value of OTD, APD, PPED, and PSA could provide a clinical reference to insertion site, depth, and angle of the tibial drill guide in PCL reconstruction.

What Kinds of Posterior Cruciate Ligament Bundles Are Preserved in Cruciate-Retaining Total Knee Arthroplasty? A Three-Dimensional Morphology Study.

In this study, the effects of tibial bone cutting on the attachment area of the posterior cruciate ligament (PCL), including both the anterolateral bundle (ALB) and posteromedial bundle (PMB), in cruciate-retaining total knee arthroplasty (CR-TKA) were simulated using a three-dimensional (3D) model of the tibial reconstruction. A total of 40 knees with medial osteoarthritis in patients scheduled for TKA were evaluated. Following surface registration of 3D computed tomography (CT) and 3D magnetic resonance imaging (MRI) models of the tibia with the PCL, the area of PCL attachment was calculated. Tibial bone cutting in the 3D CT model was simulated at 8 and 10 mm distal to the center of the lateral articular surfaces of the tibia and with posterior tibial slope angles of 0, 7, and 10 degrees. The percentages of the ALB and PMB tibial attachment areas that remained after cutting at 8 mm were, respectively, 21.8 ± 19.7% and 86.3 ± 17.7% with 0 degrees, 9.5 ± 10.4% and 64.1 ± 23.6% with 7 degrees, and 8.1 ± 6.7% and 51 ± 25.3% with 10 degrees. These results suggest that only half of the PCL attachment area was left after the bone cut simulation. Complete preservation of the ALB and PMB attachment areas requires appropriate selection of surgical procedures and devices.

Two cases of the arthroscopic pulling out method for tibial avulsion fracture of the attachment of posterior cruciate ligament

Two cases of the arthroscopic pulling out method for tibial avulsion fracture of the attachment of posterior cruciate ligament

Avulsion fracture of femoral attachment of posterior cruciate ligament: a case report and literature review

The avulsion fracture of the femoral attachment from the posterior cruciate ligament (PCL) is quite rare, particularly in adults. The patient we presented here was admitted to receive treatment in June 2017, whose knee injury resulted in avulsion fractures at three sites, the femoral attachment of the PCL, the tibial insertion of the anterior cruciate ligament (ACL), and the femoral attachment of the medial collateral ligament (MCL). We repaired PCL femoral attachment by arthroscopy and fixed MCL femoral insertion with cannulated screws.

Variations in Tibial Tuberosity to Trochlear Groove and Posterior Cruciate Ligament Distances due to Tibial External and Valgus Rotations.

Tibial rotations with respect to the femur influence measurements used to assess the lateral position of the tibial tuberosity. This study utilized computational modeling to quantify how the tibial tuberosity to trochlear groove (TT-TG) and tibial tuberosity to posterior cruciate ligament attachment (TT-PCL) distances vary with tibial internal/external and varus/valgus rotations. Computational models were developed from magnetic resonance imaging data to represent eight knees with patellar instability. TT-TG and TT-PCL distances were quantified from the computational models for a neutral orientation and with the tibia rotated internally and externally and into varus and valgus in 1-degree increments to 5 degrees. Regression analyses related tibial rotations to TT-TG and TT-PCL distances. TT-TG distance increased with tibial external rotation, and both TT-TG and TT-PCL distances increased with valgus orientation (r2 > 0.94 for all regressions). The average increase in TT-TG distance for each 1 degree of tibial external rotation was 0.55 mm (range: 0.50-0.62 mm), compared with 0.00 mm (range: -0.05 to 0.04 mm) for TT-PCL distance. The average increase in TT-TG distance for each 1 degree of valgus was 1.01 mm (range: 0.91-1.14 mm), compared with 0.46 mm (range: 0.32-0.60 mm) for TT-PCL distance. TT-TG distance varies more with tibial rotations than TT-PCL distance due to both points being on the tibia and a smaller proximal-distal distance between the points for TT-PCL distance.

MRI analysis of tibial PCL attachment in a large population of adult patients: reference data for anatomic PCL reconstruction.

BackgroundConsistent reference data used for anatomic posterior cruciate ligament (PCL) reconstruction is not well defined. Quantitative guidelines defining the location of PCL attachment would aid in performing anatomic PCL reconstruction. The purpose was to characterize anatomic parameters of the PCL tibial attachment based on magnetic resonance imaging (MRI) in a large population of adult knees.MethodsThe PCL tibial attachment site was examined in 736 adult knees with an intact PCL using 3.0-T proton density–weighted sagittal MRI. The outcomes measured were the anterior-posterior diameter (APD) of the tibial plateau; angle between the tibial plateau and the posterior tibial ‘shelf’ (the slope where the PCL tibial attachment site was) (PTS); length of the PTS; proximal, central, and distal PCL attachment positions as well as the width of the PCL attachment site; and vertical dimension of the PCL attachment site inferior from the tibial plateau.ResultsThe average APD of the tibia plateau was 33.6 ± 3.5 mm, yielding significant differences between males (35.5 ± 3.0 mm) and females (31.6 ± 2.7 mm), P <.05, and there was a significantly decreasing trend with increasing age in males (P <.05). Mean angle between the tibial plateau and the PTS was 122.4° ± 8.1°, and subgroup analysis showed that the young group had a differently smaller angle (120.9° ± 7.5°) than the middle-aged (123.7° ± 8.2°) and the old (123.4° ± 7.7°) in males population, while there were no significant differences between sexes (P >.05). The proximal, central positions and width of the PCL attachment site were 13.4 ± 3.0 mm, 17.8 ± 3.0 mm and 9.6 ± 2.4 mm along the PTS, with significant differences between males and females (P <.05), and accounted for 60.0 % ± 9.1 %, 80.0 % ± 4.6 % and 43.3 % ± 9.7 % of the PTS respectively, with no significant differences between sexes and among age groups (all P >.05).ConclusionsThis study provides reference data of the tibial PCL attachment based on MRI in the sagittal orientation. In analysis of retrospective data from a large population of adult patients, the quantitative values can be used as references to define the inserted angle and depth of the drill guide, and the exact position and size of the tibial PCL tunnel for performing arthroscopic anatomic PCL reconstruction.

Unique Anatomic Feature of the Posterior Cruciate Ligament in Knees Associated With Osteochondritis Dissecans.

Background:Osteochondritis dissecans (OCD) of the knee is a disorder in juveniles and young adults; however, its etiology still remains unclear. For OCD at the medial femoral condyle (MFC), it is sometimes observed that the lesion has a connection with fibers of the posterior cruciate ligament (PCL). Although this could be important information related to the etiology of MFC OCD, there is no report examining an association between the MFC OCD and the PCL anatomy.Purpose:To investigate the anatomic features of knees associated with MFC OCD, focusing especially on the femoral attachment of the PCL, and to compare them with knees associated with lateral femoral condyle (LFC) OCD and non-OCD lesions.Study Design:Case-control study; Level of evidence, 3.Methods:We retrospectively reviewed 39 patients (46 knees) with OCD lesions who had undergone surgical treatment. Using magnetic resonance imaging (MRI) scans, the PCL attachment at the lateral wall of the MFC was measured on the coronal sections, and the knee flexion angle was also measured on the sagittal sections. As with non-OCD knees, we reviewed and analyzed 25 knees with anterior cruciate ligament (ACL) injuries and 16 knees with meniscal injuries.Results:MRIs revealed that the femoral PCL footprint was located in a significantly more distal position in the patients with MFC OCD compared with patients with LFC OCD and ACL and meniscal injuries. There was no significant difference in knee flexion angle among the 4 groups.Conclusion:The PCL in patients with MFC OCD attached more distally at the lateral aspect of the MFC compared with knees with LFC OCD and ACL and meniscal injuries.

Dynamic tracking influenced by anatomy in patellar instability

BackgroundThe current study was performed to correlate anatomical parameters related to trochlear dysplasia, tibial tuberosity position, and patella alta with in vivo patellar tracking for subjects with recurrent patellar instability. MethodsEight subjects with recurrent patellar instability that failed conservative treatment were evaluated using computational reconstruction of in vivo knee motion. Computational models were created from dynamic CT scans of the knee during extension against gravity. Shape matching techniques were utilized to position a single model of each bone (femur, patella and tibia) to represent multiple positions of knee extension. Patellar tracking was characterized by the bisect offset index (lateral shift) and lateral tilt. Anatomical parameters were characterized by the inclination of the lateral ridge of the trochlear groove, the lateral distance from the tibial tuberosity to the posterior cruciate ligament attachment (lateral TT–PCL distance), and the Caton–Deschamps index. Stepwise multivariable linear regression analysis was used to relate patellar tracking to the anatomical parameters at low (<20°) and high flexion angles. ResultsAt low flexion angles, both lateral trochlear inclination and lateral TT–PCL distance were significantly correlated with bisect offset index (p=0.02). Only lateral trochlear inclination was significantly correlated with lateral tilt (p<0.001). At high flexion angles, bisect offset index and lateral tilt were correlated with only lateral TT–PCL distance (p≤0.02). ConclusionParameters related to trochlear dysplasia and tibial tuberosity position were both related to patellar tracking, but the relationship changed with the flexion angle. Clinical relevanceThe anatomical parameters related to patellar tracking can be used to evaluate the risk of continued instability and guide surgical treatment.

Consequences of Tibial Tunnel Reaming on the Meniscal Roots During Cruciate Ligament Reconstruction in a Cadaveric Model, Part 2

Background: Recent emphasis has turned to reconstructing the posterior cruciate ligament (PCL) after injury. However, single-bundle PCL reconstruction of the anterolateral bundle may potentially injure the posterior meniscal roots. Purpose/Hypothesis: The purpose of this study was to determine if posterior meniscal root injuries occurred because of tunnel reaming for single-bundle PCL reconstruction. It was hypothesized that tibial tunnel reaming within the anterolateral bundle footprint during PCL reconstruction would result in clinically significant decreases in posteromedial (PM) root attachment areas and in ultimate failure strength for the PM root. Study Design: Controlled laboratory study. Methods: Testing was performed on 12 matched pairs of human cadaveric knees. For each pair of knees, one knee was left intact, while the contralateral knee was prepared with a tibial tunnel placed 5 mm anterior to the center of the tibial PCL attachment and within the previously described footprint of the anterolateral bundle of the PCL for single-bundle PCL reconstruction. The attachment areas of the posterior meniscal roots were measured with a coordinate measuring device before and after PCL tunnel reaming. The posterior meniscal roots were then pulled to failure with a dynamic tensile testing machine. Results: There was a significant mean decrease in the attachment area of the PM root (%Δ, 28%; 95% CI, 16-40) after PCL tunnel reaming compared with the intact state (P = .005). The mean ultimate failure strength of the native PM root (mean, 440 N; 95% CI, 347-534) was also significantly stronger (mean, 40%; 95% CI, 18-61; P = .005) than that of the PM root after PCL tunnel reaming (mean, 243 N; 95% CI, 176-309). No changes were found for the posterolateral (PL) root after PCL tunnel reaming. Conclusion: Tibial tunnel reaming for single-bundle PCL reconstruction in the anterolateral bundle footprint significantly reduced the ultimate failure strength and attachment area of the PM meniscal root. The attachment area and ultimate failure strength of the PL root were unaffected by tunnel reaming. Clinical Relevance: Tibial tunnels reamed in the footprint of the anterolateral bundle during single-bundle PCL reconstruction can cause iatrogenic damage to the PM meniscal root attachment. Thus, tibial tunnels should strive to be reamed in the center of the entire tibial PCL attachment site during PCL reconstruction.

Change in tibiofemoral rotational alignment during total knee arthroplasty

BackgroundRotational mismatch between femoral and tibial components has been recognized as a risk factor of unsuccessful total knee arthroplasty (TKA), but a main cause of rotational mismatch is uncertain. This study aims to evaluate rotational alignment of the knee by measuring both component rotation and version of the knee in TKA. MethodFifty-one TKAs (mean age 73.7 years) were included in this study. The three dimensional, weight-bearing knee alignment was measured before and after TKA. A transepicondylar axis was referenced to femoral component rotation, and an anteroposterior axis of the tibia (middle of posterior cruciate ligament attachment to medial border of patella tendon attachment) was referenced to tibial component rotation. Knee rotational angle was defined as the angle between these two axes. ResultThe mean preoperative knee rotation angle of 9.7° (±8.5°) internal rotation was significantly reduced to 1.8° (±7.3°) external rotation after TKA. Twenty-one of 51 knees (41 %) exhibited rotational mismatch (>10°) preoperatively, and this number was reduced to eight knees (16 %) post-TKA. The femoral component was rotationally aligned within 5° of neutral in all knees, while rotational alignment of the tibial component showed a high degree of variability (range 20.7° internal rotation to 17.2° external rotation). ConclusionRotational malposition of the tibial component was considered to be a main factor of rotational mismatch of the knee after TKA.

Functional evaluation in cruciate-retaining-type TKA: anatomical relationship between tibial osteotomy level and PCL attachment

The level and morphology of posterior cruciate ligament (PCL) attachment vary greatly among individuals, and the function of the PCL after tibial osteotomy performed during total knee arthroplasty (TKA) surgery remains unclear. Therefore, we evaluated the resection amount of PCL attachment and the function of the residual PCL in cruciate-retaining (CR)-type TKA. We examined 76 patients with knee osteoarthritis who had undergone CR-type TKA. The level of the tibial PCL attachment was measured by preoperative MRI and the amount resected into the tibial PCL attachment from the osteotomy level as well as the longitudinal diameter of the residual PCL by postoperative radiography. The relationships between these and joint gap tension value at flexion or amount of tibial posterior transfer by postoperative stress radiography were examined. The longitudinal diameter of the PCL attachment and the attachment level varied widely among patients. There were 39 patients (51%) with tibial osteotomy level caudal to the PCL attachment. Flexion gap tension in patients with residual PCL (residual PCL group) was slightly higher than those without residual PCL (fully-resected group). There was no correlation between amount of PCL residual and joint gap tension at the flexion position. Even in those without residual PCL, no correlation was observed between the resected amount and flexion joint gap tension value. Comparison of amount of posterior transfer by postoperative stress radiography between those with and without residual PCL revealed no significant difference. It was confirmed that the level and morphology of the PCL attachment vary greatly among individuals and the amount of PCL resected at tibial osteotomy during TKA surgery varies depending on the patient. The tension due to flexion position tended to decrease if the tibial osteotomy line was caudal to the PCL attachment; however, the amount of tibial posterior transfer due to stress was not changed.

Radiographic Landmarks for Tunnel Positioning in Posterior Cruciate Ligament Reconstructions

Background: Consistent radiographic guidelines for tunnel placement in single- or double-bundle posterior cruciate ligament (PCL) reconstructions are not well defined. Quantitative guidelines reporting the location of the individual PCL bundle attachments would aid in intraoperative tunnel placement and postoperative assessment of a PCL reconstruction. Hypothesis: Consistent and reproducible measurements in relation to radiographic landmarks for the entire PCL and its individual bundle attachments are achievable. Study Design: Controlled laboratory study. Methods: The femoral and tibial PCL bundle attachment centers of 20 nonpaired fresh-frozen cadaveric knees were labeled using radio-opaque spheres and the attachment areas were labeled using barium sulfate. Anteroposterior (AP) and lateral radiographs of the femur and tibia were obtained, and measurements of the distances between the PCL bundle centers and landmarks were acquired. Results: On the AP femur view, the anterolateral bundle (ALB) and posteromedial bundle (PMB) centers were 34.1 ± 3.0 mm and 29.2 ± 3.0 mm lateral to the most medial border of the medial femoral condyle, respectively. The lateral femur images revealed that the ALB center was 17.4 ± 1.7 mm and the PMB center was 23.9 ± 2.7 mm posteroproximal to a line perpendicular to the Blumensaat line that intersected the anterior margin of the medial femoral condyle cortex. Anteroposterior tibia images revealed that the ALB and PMB centers were located 0.2 ± 2.1 mm proximal and 4.9 ± 2.9 mm distal to the proximal joint line, respectively. The PCL attachment center was 1.6 ± 2.5 mm distal to the proximal joint line. On the lateral tibia view, the ALB center was 8.4 ± 1.8 mm, the PCL attachment center was 5.5 ± 1.7 mm, and the PMB center was 2.5 ± 1.5 mm superior to the champagne glass drop-off of the posterior tibia. Conclusion: Radiographic measurements from several clinically relevant views of the femur and tibia were reproducible with regard to the anatomic locations of the ALB and PMB centers. The measurements from the lateral femur and tibia views provided the most clinically pertinent radiographic measurements intraoperatively. Clinical Relevance: This study established a set of clinically relevant radiographic guidelines for anatomic reconstruction of the PCL. The parameters set forth in this study can be used in both the intraoperative and postoperative settings for both single- and double-bundle PCL reconstructions.