Table 4.

Univariate analysis of patient clinical and radiographic variables

Parameter	Patellar crepitus		Control		p value
	Mean ± SD	Median (range)	Mean ± SD	Median (range)
Preoperative extension (°)	4.5 ± 4.0	5 (0 to 15)	6.2 ± 6.2	5 (0 to 20)	0.0843
Preoperative flexion (°)	117.3 ± 11.5	120 (85 to 140)	117.0 ± 14.1	120 (70 to145)	0.9030
Preoperative alignment (°)	0.0 ± 8.6	−3 (−15 to 28)	1.2 ± 8.6	−3 (−10 to 21)	0.4742
Postoperative extension (°)	0.3 ± 1.0	0 (0 to 5)	0.4 ± 1.2	0 (0 to 6)	0.8135
Postoperative flexion (°)	122.7 ± 9.1	120 (90 to 140)	122.1 ± 10.6	120 (85 to150)	0.7122
Postoperative alignment (°)	4.9 ± 1.0	5 (3 to 7)	5.0 ± 1.2	5 (2 to 7)	0.4236
Preoperative patellar tendon length (mm)	54.5 ± 6.6	55.0 (40.0 to 70.0)	58.0 ± 7.4	57 (44 to 82)	0.0089
Preoperative Insall-Salvati ratio	1.5 ± 0.2	1.5 (0.9 to 1.9)	1.5 ± 0.2	1.5 (1.2 to 2.0)	0.1493
Postoperative patellar tendon length (mm)	54.6 ± 6.7	53.5 (39.6 to 71.0)	58.1 ± 7.8	58 (43 to 82)	0.0089
Postoperative Insall-Salvati ratio	1.5 ± 0.2	1.5 (0.8 to 2.2)	1.5 ± 0.2	1.5 (1.1 to 2.0)	0.2142
Femoral component flexion (°)	1.5 ± 2.0	1.1 (−3.0 to 7.0)	0.8 ± 3.0	0 (−5 to10)	0.1262
Posterior femoral offset (mm)	1.3 ± 2.7	1 (−5 to 10)	0.2 ± 2.3	0 (−5 to 4)	0.0230
Posterior tibial slope (°)	2.8 ± 2.3	3 (−4 to 8)	3.2 ± 2.2	3 (−2 to 9)	0.343
Posterior tibial offset (mm)	1.8 ± 1.6	2 (0 to 6)	2.0 ± 1.7	2 (0 to 6)	0.3889
Anterior tibial offset (mm)	0.9 ± 1.6	0 (−2 to 8)	0.8 ± 1.3	0 (−1 to 4)	0.7406
Preoperative patellar thickness (mm)	20.9 ± 2.8	21 (14 to 28)	21.4 ± 2.1	21 (18 to 27)	0.4118
Postoperative patellar thickness (mm)	13.6 ± 1.7	14 (9 to 17)	14.1 ± 1.8	10 (14 to17)	0.2710
Composite patellar thickness (mm)	22.3 ± 2.1	22.5 (16.8 to 28.4)	23.2 ± 2.4	23.1 (18.5 to 28.4)	0.0219
Patellar tilt (°)	0.5 ± 5.4	0 (−12 to 18)	1.6 ± 4.4	0 (−10 to 15)	0.2456
Change in joint line (mm)	0.6 ± 3.4	0 (−7 to 13)	0.0 ± 3.5	0 (−7 to 9)	0.4025