Table 1.

A comparative overview of demographic variables under investigation.

Variable	Group				p value
	Ia	Ib	IIa	IIb
Age (years)	63.67 ± 5.95	68.53 ± 5.18	66.57 ± 5.07	66.00 ± 5.69	0.171
Sex (F/M)	22/2	14/3	26/2	8/3	0.293
Body mass index (kg/m2)	32.79 ± 1.47	36.65 ± 1.00	33.18 ± 1.61	36.91 ± 0.83	<0.001
Side of involvement (R/L)	15/9	13/4	17/11	8/3	0.674