Objective: To determine the Pearson correlation coefficient (r) and ratio of the adductor tubercle to joint line distance (ADJ) and the patellar facet height (PFH) by sex.

Materials and Methods: From 100 knee radiographs, the authors measured the ADJ and PFH and determined the ADJ-PFH distances and ADJ-PFH ratios for males and females. In addition, the authors measured these parameters and recorded the clinical outcomes [knee society scores (KSS) and range of movement (ROM)] in 22 patients (22 knees) that underwent revision total knee arthroplasty (TKA) with metal augmentation distal femur; Gp I (n=17)/without metal augmentation distal femur; Gp II (n=5).

Results: The PFH correlated positively with ADJ in males (r=0.647, p<0.001) and females (r=0.648, p<0.001) but the mean PFH and ADJ distances were significantly higher in males: (i) 31.79±2.75 versus 29.39±2.16 mm (p<0.001), and (ii) 41.35±3.78 versus 40.10±2.96 (p=0.028), respectively. The ADJ: PFH ratio was significant (p=0.042) lower in males 1.31±0.10 versus females 1.36±0.12. The KSS in Gp I patients was significantly higher than Gp II (p≤0.001). However, the ROM in Gp I versus Gp II patients were not significantly different. The mean ADJ: PFH ratio was significantly (p=0.003) in Gp I: 1.31 versus 1.07.

Conclusion: The ADJ correlated well with the PFH. The ratio of ADJ-PFH was 1.31 and 1.36 for male and female, respectively. The ADJ-PFH ratios and KSS were significantly lower in TKA patients without metallic augmentation. Revision TKAs should include metallic augmentation of the distal femur.

Keywords: Patellar height, Joint line level, Medial epicondyle, Lateral epicondyle, Transepicondylar axis width, Adductor tubercle

Received 13 Aug 2018 | Revised 12 Nov 2018 | Accepted 16 Nov 2018