Coronal femoral TKA position significantly influences in vivo patellar loading in unresurfaced patellae after primary total knee arthroplasty

• Published in: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA sports traumatology, arthroscopy : official journal of the ESSKA, 2017-11, Vol.25 (11), p.3605-3610
• Main Authors: Slevin, Omer, Schmid, Florian A., Schiapparelli, Filippo-Franco, Rasch, Helmut, Amsler, Felix, Hirschmann, Michael T.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Alignment; Arthralgia - etiology; Arthroplasty (knee); Arthroplasty, Replacement, Knee - adverse effects; Arthroplasty, Replacement, Knee - instrumentation; Arthroplasty, Replacement, Knee - methods; Biomedical materials; Computed tomography; Demographics; Diagnostic systems; Female; Femur; Femur - anatomy & histology; Femur - diagnostic imaging; Femur - surgery; Humans; Image reconstruction; Imaging, Three-Dimensional; Joint surgery; Knee; Knee Joint - diagnostic imaging; Knee Joint - surgery; Localization; Male; Medicine; Medicine & Public Health; Middle Aged; Orthopedics; Pain; Patella; Patella - anatomy & histology; Patella - diagnostic imaging; Patella - surgery; Patients; Position measurement; Postoperative Complications; Radiographs; Radiography; Resurfacing; Rotation; Single photon emission computed tomography; Single Photon Emission Computed Tomography Computed Tomography; Statistical analysis; Surfacing; Surgical implants; Technetium Tc 99m Medronate - analogs & derivatives; Tibia - diagnostic imaging; Tibia - surgery
• ISSN: 0942-2056; 1433-7347
• DOI: 10.1007/s00167-017-4627-2

Purpose As patellar tracking and loading is influenced by tibial tuberosity and trochlear groove (TT–TG) distance, patellar height, thickness and tilt as well as TKA component position, it was our hypothesis that these parameters significantly correlate with patellar BTU intensity and localization in SPECT/CT. The purpose of the study was to investigate whether TKA component position as well as the height, thickness and tilt of the unresurfaced patella influences the intensity and the distribution pattern of BTU in SPECT/CT. Methods A total of 62 consecutive patients who underwent primary TKA without patellar resurfacing were prospectively included. Demographic data such as age, gender, side and type of primary TKA were noted. All patients underwent clinical and radiological examination in a specialized knee clinic, including standardized radiographs (anterior–posterior and lateral weight bearing, patellar skyline view) and Tc-99m-HDP-SPECT/CT before, 12 and 24 months after TKA. SPECT/CT images were analysed on 3D reconstructed images. Rotational, sagittal and coronal position of the tibial and femoral TKA components was assessed using a previously validated analysis software. Measurements of BTU including intensity and anatomical distribution pattern were also performed from 3D data. The patellar height, thickness and tilt were measured, and the distance between TT and TG was measured using axial CT images. Univariate analysis was performed to identify any correlations between BTU and TKA component position and patellar measurements ( p