Table 5.

Follow-up variations of VAS score (mean [95% CI]) compared to baseline setting and stratified by radiological grade and therapy. All the estimates resulted by a quasi-randomization process obtained including propensity scores in the model for repeated measures (GEE model).

Timing x K-L grade	Hyaluronic acid 1,500–3,200 kDa	HYLAN G-F 20	Ctrls
Grade II
Baseline	66.8 [57.5 to 75.9]	68.0 [60.6 to 75.4]	73.1 [63.3 to 83.1]
1 mth vs. baseline	−16.6 [−22.3 to −10.9] p< < 0.001	−18.8 [−22.6 to −15.0] p< < 0.001	−5.1 [−9.8 to −0.4] p = 0.03
6 mths vs. baseline	−20.5 [−29.7 to −11.3] p< < 0.001	−26.6 [−32.0 to −21.2] p< < 0.001	−4.9 [−8.5 to −1.2] p = 0.01
12 mths vs. baseline	−38.7 [−48.7 to −28.7] p< < 0.001	−40.4 [−47.7 to −33.1] p< < 0.001	−2.9 [−5.7 to −0.1] p = 0.04
24 mths vs. baseline	−41.2 [−51.3 to −31.1] p< < 0.001	−46.6 [−54.0 to -39.2] p< < 0.001	−0.9 [−4.2 to 2.3] p = 0.584
Grade III
Baseline	72.1 [62.8 to 81.4]	73.3 [67.6 to 79.0]	78.4 [69.9 to 86.9]
1 mth vs. baseline	−11.3 [−18.5 to −4.1] p = 0.004	−13.5 [−20.8 to −6.2] p = 0.001	0.2 [−7.6 to 8.0] p = 0.398
6 mths vs. baseline	−15.2 [−24.6 to −5.8] p = 0.003	−21.3 [−29.7 to −12.9] p< < 0.001	0.4 [−6.7 to 7.5] P = 0.397
12 mths vs. baseline	−33.3 [−43.7 to −22.9] p< < 0.001	−35.1 [−45.0 to −25.2] p< < 0.001	2.4 [−4.4 to 9.2] 0.315
24 mths vs. baseline	−35.9 [−46.7 to −25.1] p< < 0.001	−41.3 [−50.8 to −31.8] p< < 0.001	4.4 [−2.5 to 11.3] p = 0.184
Grade IV
Baseline	69.9 [59.0 to 80.8]	71.1 [63.6 to 78.6]	76.2 [66.6 to 85.8]
1 mth vs. baseline	−13.5 [−22.6 to −4.4] p = 0.006	−15.7 [−24.5 to −6.9] p = 0.001	−2.0 [−11.1 to 7.1] p = 0.364
6 mths vs. baseline	−17.4 [−28.4 to −6.4] p = 0.003	−23.5 [−32.8 to −14.2] p< < 0.001	−1.8 [−10.8 to 7.2] p = 0.369
12 mths vs. baseline	−35.5 [−47.1 to −23.9] p< < 0.001	−37.3 [−48.1 to −26.5] p< < 0.001	0.2 [−8.2 to 8.6] p = 0.399
24 mths vs. baseline	−38.1 [−50.0 to −26.2] p< < 0.001	−43.5 [−54.4 to −32.6] p< < 0.001	2.2 [−6.7 to 11.1] p = 0.355