Internal Rotation Of Tibial Component Research Articles

EVALUATION OF TIBIAL COMPONENT ROTATION IN PAINFUL TOTAL KNEE ARTHROPLASTIES BY MRI ENHANCED WITH METAL ARTIFACT REDUCTION TECHNIQUE

Background: Tibial component malrotation is one of the commonest causes of pain and stiffness following total knee arthroplasties, however, the assessment of tibial component malrotation on imaging is not clear-cut. The objective of this study was to assess tibial component rotation in cases with pain following total knee replacement using MRI with metal artifact reduction technique. Methods: In 15 consecutive patients presented in our clinic — a high-volume arthroplasty institution — between January 2017 and June 2017 with persistent unexplained moderate to severe pain for at least 6 months following total knee arthroplasties, which were ALL done outside our institution, after exclusion of infection and loosening (tibial or femoral), MRI evaluation of tibial component rotation using metal artifact reduction for orthopedic implants (O-MAR) technique — to improve visualization of soft tissue and bone by reducing artifacts caused by metal implants — was done according to the technique of Berger et al. [Malrotation causing patellofemoral complications after total knee arthroplasty. Clin Orthop Relat Res 144–153, 1998]. Results: Eleven cases showed an internal rotation of tibial components (73.3%), four cases showed a neutral or external rotation of tibial components (26.6%), however, with the presence of abnormal intraarticular fibrous bands in two of them. Conclusions: Two main conclusions are obtained from this study: Firstly, internal rotation of tibial component must be excluded in all cases of persistent pain following total knee replacement. Secondly, magnetic resonance imaging with the newly developed metal artifact reduction techniques is a very useful tool in evaluating cases of unexplained pain following total knee replacement.

Fixed-bearing unicompartmental knee arthroplasty tolerates higher variance in tibial implant rotation than mobile-bearing designs.

UKA necessitates a learning period. From this point of view, it would be logical to prefer the design that tolerates suboptimal tibial rotations better, especially for inexperienced surgeons. The aim of this study was to evaluate and compare the clinical and radiological results of mobile-bearing and fix-bearing UKA designs in case of suboptimal tibial rotations. A retrospective case-control evaluation was made of all the patients with medial compartment osteoarthritis, treated between January 2011 and January 2015. 324 patients ideal femoral rotation were enrolled in the study. 153 patients (Group 1) were treated with fix-bearing design with a mean 28.8 ± 11.3 month follow-up and 171 patients (Group 2) were treated with mobile-bearing design with a 31 ± 14.3 month follow-up. Each patient in groups was subdivided into (A): optimal tibial rotation, (B): external rotation of tibial component > 5°, (C): internal rotation of tibial component > 5° subgroups. WOMAC and KSS scores of each patient at preoperative and postoperative final control were compared between groups and subgroups. No significant differences were determined between the groups in terms of mean follow-up time (p = 0.0612), preoperative WOMAC, and KSS scores (p = 0.754 and p = 0.832, respectively). No significant differences were determined between subgroups 1A and 2A in terms of WOMAC and KSS scores at the final evaluation (p = 0.314 and p = 0.546, respectively). A significant difference was determined between subgroups 1B and 2B in terms of WOMAC and KSS scores (p = 0.021 and p = 0.012, respectively). In addition, the difference between subgroups 1C and 2C was significant (p = 0.047 and p = 0.034, respectively) at the final evaluation. Both mobile- and fix-bearing designs are beneficial in the treatment of medial compartment osteoarthritis of the knee. However, in case of both tibial internal or external suboptimal tibial rotations, fix-bearing design have better results compared to mobile-bearing design. Level III retrospective comparative clinical study.

Medial parapatellar approach leads to internal rotation of tibial component in total knee arthroplasty.

The purpose of this study was to investigate if the type of approach [medial parapatellar approach (MPA) versus lateral parapatellar approach with tibial tubercle osteotomy (LPA)] influences rotation of femoral and/or tibial component and leg axis in total knee arthroplasty (TKA). It was the hypothesis that MPA leads to an internally rotated tibial TKA component. This study included 200 consecutive patients in whom TKA was performed using either a parapatellar medial (n=162, MPA) or parapatellar lateral approach with tibial tubercle osteotomy (n=38, LPA). All patients underwent clinical follow-up, standardized radiographs and computed radiography (CT). TKA components' position and the whole leg axis were assessed on 3D reconstructed CT scans (sagittal, coronal and rotational). Mean values of TKA component position and the whole leg alignment of both groups were compared using a t test. The tibial component was graded as internally rotated (<3° of external rotation (ER)), neutral rotation (equal or between 3° and 6° of ER) and externally rotated (>6° ER). The femoral component was graded as internally rotated [>3° of internal rotation (IR)], neutral rotation (equal or between -3° IR and 3° of ER) and externally rotated (>3° ER). There was no significant difference in terms of whole leg axis after TKA between both groups (MPA: 0.2° valgus±3.4; LPA: 0.0° valgus±3.5). Means of tibial component rotation were 2.7° ER±6.1 (MPA) and 7.6° ER±5.4 (LPA). Patients of group LPA presented a significantly less internally rotated (LPA: 18.4%; MPA: 48.8%) and more externally rotated (LPA: 52.6%; MPA: 22.8%) tibial component (p<0.001). No significant differences were seen for the femoral component position, tibial valgus/varus and tibial slope. The type of approach (medial versus lateral) significantly influenced tibial TKA component rotation. It appears that a MPA tends to internally rotate the tibial TKA component and a LPA tends to externally rotate the tibial TKA. The anterior cortex should not be used as landmark for tibial TKA component placement when using the lateral approach with tibial tubercle osteotomy. Retrospective comparative study, Level III.