Table 3

Patellofemoral cartilage thickness changes over the total (0–5 years), early (0–2 years) and late (2–5 years) follow-up periods: as-treated*

Outcome (µm)Early ACLRDelayed ACLRRehabilitation onlyEarly ACLR vs
delayed ACLR P-value
Early ACLR vs
rehab. only
P value
Delayed ACLR vs
rehab. only
P value
Change in cartilage thickness between baseline and 5-year follow-up
 Participants included in analysisn=59n=27n=26
 Patella−36 (−78 to 5)26 (−14 to 67)9 (−20 to 37)0.0520.1290.503
 Trochlea−72 (−118 to –26)−17 (−56 to 22)−21 (−51 to 10)0.1360.1920.854
 Total patellofemoral joint−108 (−189 to –27)9 (− 55 to 73)−12 (−58 to 33)0.0610.1290.573
Change in cartilage thickness between baseline and 2-year follow-up†
 Participants included in analysisn=58n=21n=33
 Patella−25 (−52 to 1)20 (−15 to 54)10 (−16 to 36)0.0540.0720.649
 Trochlea−63 (−100 to –26)−17 (−53 to 19)−31 (−56 to–6)0.1430.2090.497
 Total patellofemoral joint−88 (−145 to –31)2 (− 58 to 62)−21 (−59 to 17)0.0630.0920.481
Change in cartilage thickness between 2-year and 5-year follow-up
 Participants included in analysisn=58n=25n=24
 Patella−13 (−39 to 13)6 (−41 to 52)8 (−19 to 35)0.4830.3490.898
 Trochlea−9 (−30 to 12)5 (−28 to 39)11 (−14 to 36)0.4590.2970.810
 Total patellofemoral joint−22 (−64 to 20)11 (−56 to 78)20 (−26 to 65)0.4180.2650.842
  • P values calculated from linear mixed effects model (ie, the interaction between fixed-effects of group and follow-up periods, adjusted for age and sex).

  • *Changes in cartilage thickness (µm) are mean and 95% CI.

  • †As-treated groups as at 2-year follow-up (ie, participants with delayed ACLR between year-2 and year-5, included in rehabilitation only group at year-2). One of the 22 participants with a delayed ACLR between baseline and year-2 did not have cartilage thickness data available at year-2 (ie, only baseline and year-5).

  • ACLR, anterior cruciate ligament reconstruction.