Femoral rotation in total knee arthroplasty: a comparison of patient individualized jigs with gap balancing in relation to anatomic landmarks.
OBJECTIVE
The purpose of our study was to compare the accuracy of the rotational position of the femoral component in total knee arthroplasty aligned with patient individualized jigs (PSJ) to a gap balancing technique (GBT).


METHODS
A consecutive series of 21 osteoarthritic patients were treated with 22 cruciate-retaining total knee prostheses. During surgery, the rotation of the femoral component pinholes was recorded for all knees using PSJ and GBT and transferred to computer tomograms (CT). The rotational differences between PSJ and GBT relative to the transepicondylar axis were analysed.


RESULTS
The medium rotation of the femoral component pinholes was 1.3° ± 5.1° (min = -6.3°; max = 14.4°) for PSJ and 0.1 ± 1.4° (min = -1.6°; max = 3.4°) for GBT. Outliers of more than 3° were found more frequently with PSJ in 12 cases but only in one for GBT.


CONCLUSIONS
Based on our study, we would not recommend relying intra-operatively solely on the CT-based PSJ without the option to adjust or control femoral rotation.


METHODS
II.
Department of Orthopaedic Surgery, Brigham and Women's and Brigham Faulkner Hospital, 850 Boylston Street, Chestnut Hill, MA, 02467, USA.
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W
Fitz
Laboratory of Biomechanics and Implant Research, Department of Orthopaedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstr. 200A, 69118, Heidelberg, Germany.
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S
Jäger
Laboratory of Biomechanics and Implant Research, Department of Orthopaedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstr. 200A, 69118, Heidelberg, Germany.
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JS
Rieger
Research Centre for Experimental Orthopaedics, Heidelberg University Hospital, Schlierbacher Landstr. 200A, 69118, Heidelberg, Germany.
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E
Seebach
Laboratory of Biomechanics and Implant Research, Department of Orthopaedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstr. 200A, 69118, Heidelberg, Germany. Rudi_Georg.Bitsch@urz.uni-heidelberg.de.
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RG
Bitsch
D000368:Aged; D059925:Anatomic Landmarks / Q000601:surgery; D019645:Arthroplasty, Replacement, Knee / Q000379:methods; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D016059:Range of Motion, Articular; D012399:Rotation; D014057:Tomography, X-Ray Computed
Femoral rotation; Gap balancing; Patient-specific jigs; Total knee arthroplasty; Transepicondylar axis