Rotational Alignment of Femoral Component for Minimal Medial Collateral Ligament Release in Total Knee Arthroplasty

Elazab

2019

Knee Surg Relat Res

PurposeThe purpose of this study was to compare the predictive value of the valgus stress angle (SA), varus SA and varus-valgus SA difference (VVD) in predicting the degree of medial release in varus deformity during total knee arthroplasty (TKA).Materials and MethodsOne hundred eight TKAs (78 patients), which were performed in primary osteoarthritis with varus knee deformity, were retrospectively classified into three groups according to the degree of medial release (group A, mild release; group B, moderate release; and group C, severe release). Medical charts were reviewed, and long weight bearing standing anteroposterior radiographs and varus-valgus stress radiographs were evaluated.ResultsThe valgus SA was significantly different between group A and B and between group A and C. However, it was not significantly different between group B and C. The varus SA was significantly different between group B and C and between group A and C. However, it was not significantly different between group A and B. The VVD was significantly different in all intergroup comparisons.ConclusionsEvaluation of the VVD is more valuable in predicting the degree of medial release in TKA performed in varus knee deformity than evaluation of the simple valgus and varus SA.

“…Through meticulous preoperative radiographic evaluation, the site and degree of medial release can be predicted 7 , 9 , 20) . Many attempts have been made to achieve this goal.…”

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Preoperative Varus-Valgus Stress Angle Difference Is Valuable for Predicting the Extent of Medial Release in Varus Deformity during Total Knee Arthroplasty

Elazab

2019

Knee Surg Relat Res

“…Restoration of axial rotation of the femoral component in relation to TEA is a critical prerequisite for normal patellofemoral and tibiofemoral kinematics and balanced flexion gap in TKA 9 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19) . However, restoration of accurate rotation of the femoral component has been a challenge and failure to do so may to lead to patient dissatisfaction 7 , 9 , 13 , 20 , 21) .…”

Section: Discussionmentioning

confidence: 99%

“…Limitation of conventional instrumentation in restoration of correct femoral component rotation 5) has been considered as the commonest culprit for abnormal patellofemroal kinematics and patient dissatisfaction 6 , 7 , 8) . This limitation of conventional instrumentation is probably attributable to flexion resection in a fixed degree of external rotation to the posterior condylar line (PCL).…”

Section: Introductionmentioning

confidence: 99%

Proposed Methods for Real-Time Measurement of Posterior Condylar Angle during TKA

Behera

Chouhan

Prakash

et al. 2014

Knee Surg Relat Res

PurposeConventional instruments are known to result in high numbers of outliers in restoring femoral component rotation primarily due to fixed degree of external rotation resection relative to the posterior condylar line (PCL). Outliers can be reduced by determining the patient specific posterior condylar angle (PCA) preoperatively or intraoperatively. There is a paucity of methods that can be used during surgery for determining the PCA. We propose two simple, real-time methods to determine the PCA and hence to measure the axial anatomical variation during surgery.Materials and MethodsThe study was conducted using axial computed tomography (CT) scans of the knees of 26 patients. The commercial software K-PACS and our proposed two methods (trigonometric and protractor) were used to measure the angle between the transepicondylar axis and PCL, i.e., PCA. Statistical comparison between the mean angles obtained by K-PACS and our methods were done.ResultsThe three methods resulted in similar PCAs. The mean PCA measured by the three methods were similar. The mean PCA value measured by the K-PACS, trigonometric method and protractor method was 6.27° (range, 0° to 12°), 6.23° (range, 0° to 11.11°) and 6.31° (range, 0° to 12°), respectively. There were significant correlations between the K-PACS measured PCA and trigonometrically or protractor measured PCA.ConclusionsOur novel, simple, easily reproducible, real-time and radiation-free PCA measurement methods obviate the need for preoperative CT scan for identification of patient specific PCA.

Knee Surg Sports Traumatol Arthrosc

“…The posterior femoral condyle bone resection thickness and the rotation of the femoral component affect the flexion joint gap [3,5,13].…”

Section: Introductionmentioning

confidence: 99%

Posterior reference guides do not always maintain the size of posterior femoral condyles in TKA

Minoda

Mizokawa

Ohta

et al. 2015

This study showed that posterior femoral condyle bone resection thickness was different for each posterior reference guide. The rotation centre of posterior reference guides influenced the bone resection thickness in the posterior femoral condyle. The size of the posterior femoral condyles increased in some guides but decreased in other guides. The maximum differences in size changes of the posterior femoral condyles between the guides were 1.9 mm at 0° external rotation, 4.1 mm at 3° external rotation, and 6.3 mm at 6° external rotation. To control the size of posterior femoral condyles, the posterior reference guide design should be checked before use.