Table 1.

Background characteristics of the four groups

Groups	Lumbar (n = 81)	Hip (n = 106)	Knee (n = 43)	Foot & Ankle (n = 27)
Demographic data
Age (year), mean (SD)	71.5 (6.9)	69.2 (6.3)§	73.7 (7.1) #,¶	68.9 (6.0)§
Sex, female, n (%)	48 (59.3%)#	93 (87.7%)†	35 (81.4%)	21 (77.8%)
Height (cm), mean (SD)	157.9 (8.8)	154.1 (8.1)	154.7 (8.3)	156.2 (9.9)
Weight (kg), mean (SD)	56.3 (11.8)	55.1 (10.0)§,¶	60.4 (10.9) #	62.6 (12.3) #
BMI (kg/m2), mean (SD)	23.9 (3.4)	23.2 (3.7)§,¶	25.1 (3.7) #	25.5 (3.7) #
Disease pathology (n)	LSS (81)	Hip OA (100) ANFH (6)	Knee OA (42) SONK (1)	Ankle OA (13) Midfoot OA (4) Foot deformity (10)
Surgery (n)	Decompression (55) Short-segment spinal fusion (26)	THA (106)	TKA (33) HTO (8) UKA (2)	Arthrodesis (15) Corrective osteotomy (12)
Preoperative LS status
Prevalence of LS (stage 1 and 2), %	100%	100%	100%	100%
Prevalence of LS stage 2, %	95.1%	95.3%	100%	85.2%
Inclusion Criteria
・Patients underwent surgeries for degenerative diseases of the lumbar spine or lower extremities in our hospitals from January 2016 to December 2018.
・Patients agreed to participate in the pre- and postoperative physical examinations.
Exclusion Criteria
・Patients were younger than 60 years of age.
・Patients had incomplete data at the three points (preoperatively and at 6 and 12 months postoperatively).
・Patients underwent another surgery for spinal or extremity disorders during the study period.

^†P < 0.05 versus Lumbar group, ^#P < 0.05 versus Hip group, ^§P < 0.05 versus Knee group, ^¶P < 0.05 versus Foot & Ankle group,

ANFH avascular necrosis of the femoral head; BMI body mass index; HTO high tibial osteotomy; LS locomotive syndrome; LSS lumbar spinal stenosis; OA osteoarthritis; SD standard deviation; SONK spontaneous osteonecrosis of the knee; THA total hip arthroplasty; TKA total knee arthroplasty; UKA unicompartmental knee arthroplasty