Table 2 Between-groups differences (Insall with/without TTO)^a

Pathoanatomical risk factors on MRI

n = 39

n = 5

 LTI, mean (SD; range)

7.2 (8.4; −14-23)

4.3 (8.6; −14-13)

n.s

 TT-TG distance, mean (SD; range)

15.0 (4.8; 7–24)

20.2 (4.9; 16–25)

p < 0.05

 Caton - Deschamps Index, mean (SD; range)

1.2 (0.2; 0.9–1.7)

1.1 (0.2; 0.9–1.4)

n.s

Outcomes

n = 41

n = 5

 Postoperative recurrent patellar dislocation (%)

12.2

0

n.s

 Reoperations (%)

14.6

20.0

n.s

Patient reported outcome measurements

n = 37

n = 5

 BPII 2.0 (SD; range)

60.9 (19.0; 26–98)

57.1 (14.9; 45–82)

n.s

 Kujala (SD; range)

76.5 (13.4; 52–100)

67.2 (22.0; 40–93)

n.s

 VAS of satisfaction (SD; range)

77.3 (26.4; 10–100)

86.0 (23.7; 44–100)

n.s