Does the femur roll-back with flexion?

Pinskerová, V.; Johal, P.; Nakagawa, S.; Sosna, A; Williams, Andrew M.; Gedroyc, W.; Freeman, Michael

doi:10.1302/0301-620x.86b6.14589

Cited by 204 publications

(127 citation statements)

References 6 publications

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“…The slight decrease in the MA, using the TF contact method, in terminal extension agrees with the fact that the tibiofemoral contact point moves anteriorly during this part of extension (Buford, Jr. et al, 1997;Pinskerova et al, 2004). Since one of these studies (Kellis and Baltzopoulos, 1999) used a slow extension movement with a simulated maximal extensor load and the others were static without load, it would appear that overall muscle loading did not alter the MA, when calculated using the TF contact method.…”

Section: Discussionsupporting

confidence: 61%

“…As open MRI technology improves, experiments looking at the full range of motion will become available. Yet, in the range excluded from this study, the FHA is primarily static (Woltring, 1994), being guided by the circular posterior femoral condyles (Pinskerova et al, 2004). Thus, at higher knee angles, the MA likely continues to decrease with increasing knee angle, due to a posterior displacement of the patellar tendon line of action.…”

Section: Discussionmentioning

confidence: 92%

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The 3D patellar tendon moment arm: Quantified in vivo during volitional activity

Sheehan¹

2007

Journal of Biomechanics

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The patellar tendon moment arm is a critical quantity in that it defines the quadriceps ability to generate a moment on the tibia. Thus, the primary purpose of this study was to establish the first in vivo three-dimensional measures of the patellar tendon moment arm, measured non-invasively and in vivo during dynamic activity in a large normative population (n=34) using a dynamic MRI technique (fast-PC MRI). The magnitude of the moment arm was defined as the shortest distance between the finite helical axis and the patellar tendon line of action. Using these data, the hypothesis that the patellar tendon moment arm is independent of gender was tested. In general, the moment arm increased from 20 mm to 50 mm during knee extension. There were significant differences (P<0.05) in the moment arm between gender, but these differences were eliminated when the moment arm was scaled by the femoral epicondylar width. This study took a large step forward towards the ultimate goal of defining how pathology may alter joint dynamics through alteration in moment arms by establishing the first in vivo normative data base for the patellar tendon moment arm using noninvasive measures during volitional activity in a relatively large population (n=34). The fact that the scaled moment arm was independent of gender may lend insights into impairments that tend to be gender specific, such as patellar maltracking. The next steps will be to quantify the patellar tendon moment arm in populations with specific pathologies.

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Section: Discussionsupporting

confidence: 61%

Section: Discussionmentioning

confidence: 92%

The 3D patellar tendon moment arm: Quantified in vivo during volitional activity

Sheehan¹

2007

Journal of Biomechanics

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“…Second, our radiographs in flexion were nonweightbearing. Most but not all [18] published kinematic results are weightbearing, making it difficult to compare our nonweightbearing findings to prior literature. Johal et al [10] observed tibiofemoral movement in 10 weightbearing and nonweightbearing Caucasian knees using MRI and found tibial internal rotation with flexion was present in both groups but was a magnitude of rotation greater and occurred earlier with weightbearing.…”

Section: Discussionmentioning

confidence: 84%

Does a Modified Gap-balancing Technique Result in Medial-pivot Knee Kinematics in Cruciate-retaining Total Knee Arthroplasty?: A Pilot Study

Fitz¹,

Sodha

Reichmann

et al. 2012

Clinical Orthopaedics &Amp; Related Research

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Background Normal knee kinematics is characterized by posterior femorotibial rollback with tibial internal rotation and medial-pivot rotation in flexion. Cruciate-retaining TKAs (CR-TKAs) do not reproduce normal knee kinematics. Questions/purposes We hypothesized a more anatomic reconstruction of the medial femoral condyle, simultaneously preserving the tension of the PCL and medial collateral ligament, resulted in (1) medial-pivot rotation and tibial internal rotation, (2) lateral femoral rollback, and (3) reduced liftoff. Patients and Methods We compared 10 patients who underwent CR-TKA using the new technique at their 1-year followup to a matched control group of nine patients using a traditional gap-balancing technique at their 2-to 4-year followup. All patients received lateral radiographs in extension and flexion, which we utilized for threedimensional implant matching to calculate tibial internal rotation, lateral rollback, and lateral liftoff in extension and flexion. Results The new gap-balancing technique resulted in a median of 3.5°tibial internal rotation with 2.7-mm rollback of the lateral femoral condyle relative to the medial condyle in flexion, which was different from the control group. We found no differences in liftoff between the groups. Conclusions The new technique resulted in tibial internal rotation with flexion and lateral rollback comparing the lateral to the medial condyle in flexion, but no differences in condylar liftoff. These preliminary results were comparable to published kinematic results of an asymmetric CR-TKA or medial-pivot CR-TKA but not to symmetric CR-TKA.

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“…Healthy knee kinematics show a rollback movement of the femur during flexion, particularly of the lateral femoral condyle, concomitant with tibial internal rotation [15,18,28]. Most studies show that the medial femoral condyle hardly moves anteroposteriorly from full extension to 120°of flexion, whereas the lateral femoral condyle moves posteriorly to a variable extent.…”

Section: Discussionmentioning

confidence: 99%

Improved kinematics of total knee replacement following partially navigated modified gap-balancing technique

Baier

Fitz

Craiovan

et al. 2013

International Orthopaedics (SICOT)

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Purpose Navigation-based total knee arthroplasty (TKA) has proven its value for restoration of the limb axis. However, patient-orientated results after TKA show a wide variation from the correct implantation technique. Nonphysiological kinematics without posterior femoral rollback and tibial internal rotation in flexion could be one reason for this. We postulated that a modified gap-balancing technique with navigation of the tibia alone, in comparison to a conventional navigated technique, would: (1) obtain lateral femoral rollback, (2) alter condylar liftoff without midflexion instability, (3) significantly differ in femoral and tibial cuts, (4) not be inferior in leg-axis restoration and (5) be comparable in clinical short-term scores. Methods In this prospective study, we compared in vivo navigation-based kinematics pre-and postoperatively of 40 consecutive TKA comprising 21 conventional navigationbased TKA and 19 TKA with the modified gap-balancing technique and a reduced navigation workflow. All cuts were double checked and compared with cuts proposed by the navigation system. Clinical results were assessed preoperatively and six months postoperatively. Results The modified gap-balancing technique resulted in significantly increased lateral femoral rollback (mean 16.3 mm) and lateral condylar liftoff (mean 1.3 mm) compared to the conventional group. The modified technique comprised an average of 2.1 mm less distal femoral resection and an average of 4°less external rotation and 3.5°more flexion of the femoral component compared with the control group. Average tibial resection height was 1.1 mm greater and average tibial slope was 0.5°elevated compared to the control group. A neutral leg axis was achieved in all cases. Results showed no significant differences in clinical scores between groups. Conclusion A partial navigation solely of the tibial cut can securely restore the leg axis. Modification of the surgical technique can possibly reproduce more physiological knee kinematics with higher lateral femoral rollback in flexion without midflexion instability. This might help reduce postoperative problems with the new implant and thus reduce the amount of unsatisfactory results. Despite equal short-term results, mid-to long-term results are needed to prove whether or not this correlates with better clinical results and at least equal implant longevity.

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Does the femur roll-back with flexion?

Cited by 204 publications

References 6 publications

The 3D patellar tendon moment arm: Quantified in vivo during volitional activity

The 3D patellar tendon moment arm: Quantified in vivo during volitional activity

Does a Modified Gap-balancing Technique Result in Medial-pivot Knee Kinematics in Cruciate-retaining Total Knee Arthroplasty?: A Pilot Study

Improved kinematics of total knee replacement following partially navigated modified gap-balancing technique

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