Mid-term outcomes of a novel liner design in kinematically-designed cruciate-retaining total knee arthroplasty

Table 1 Patient demographics, n (%)

	Knees (n = 139)
Sex
Male	53 (38.1)
Female	86 (61.9)
Age (years) (range)	66.0 (39 to 85)
Race
White	94 (67.6)
Black or African American	21 (15.1)
Asian	3 (2.2)
Other	21 (15.1)
Smoking status
Current	4 (2.9)
Former	55 (39.6)
Never	80 (57.6)
ASA score
1	2 (1.4)
2	99 (71.2)
3	37 (26.6)
4	1 (0.7)
BMI (kg/m2) (range)	31.4 (20.5 to 51.2)
CCI1	3.4 (0 to 13)
Primary diagnosis
Primary OA	137 (98.6)
Post-traumatic OA	2 (1.4)
Time to follow-up (days) (SD)	851.8 (135.9)

¹n = 110 due to differences in data availability between centers.

ASA: American Society of Anesthesiologists; BMI: Body mass index; CCI: Charlson comorbidity index; OA: Osteoarthritis; RA: Rheumatoid arthritis; SD: Standard deviation.

Table 2 Intraoperative and implant variables, n (%)

	Knees (n = 139)
Operative time (minutes) (range)1	100.8 (71 to 196)
Anesthesia
General	14 (10.1)
Spinal/regional/block	125 (89.9)
Laterality
Right	61 (43.9)
Left	76 (54.7)
Bilateral	2 (1.4)
Patellar resurfacing/fixation
Cemented	123 (88.5)
Porous (cementless)	12 (8.6)
Non-resurfaced	4 (2.9)
Bearing surface
Oxidized zirconium-on-polyethylene	39 (28.1)
Cobalt chrome-on-polyethylene	100 (71.9)

¹n = 91 due to differences in data availability between centers.

Table 3 Clinical outcomes, n (%)

	Knees (n = 139)
Mean LOS (days) (range)1	1.4 (0.3 to 7.2)
Discharge disposition
Home	132 (95.0)
SNF	7 (5.0)
90-day ED visits	2 (1.4)
90-day readmissions	6 (4.3)
Wound dehiscence	1
DVT	1
PJI	1
Non-orthopedic related	3
MUA	1 (0.7)
All-time revisions	2 (1.4)
Septic revision	2
Aseptic revision	0

¹n = 117 due to differences in data availability between centers.

LOS: Length of hospital stay; SNF: Skilled nursing facility; ED: Emergency department; DVT: Deep venous thrombosis; PJI: Peri-prosthetic joint infection; MUA: Manipulation under anesthesia.

Table 4 Patient-reported outcome measures¹

		Mean KOOS, JR (SD)	P value
Preoperative	n = 63	42.8 (18.0)
Six months	n = 73	60.6 (14.4)
Two years	n = 57	70.8 (19.1)
Δ Preop to six months	n = 61	17.4 (18.9)	< 0.001
Δ Preop to two years	n = 46	26.1 (19.7)	< 0.001

¹Variations in n due to differences in patient follow-up and availability of patient-reported outcome measures.

KOOS, JR: Knee Injury and Osteoarthritis Outcome Score for Joint Replacement; SD: Standard deviation; Δ Preop: Difference between pre- and postoperative scores.