Patient reported outcome measures in anterior cruciate ligament rupture and reconstruction: The significance of outcome score prediction

Table 1 Demographics of subjects

ACL patients (n = 50)
Mean Age (yr) (SD)	30 (9)
Male:Female	36:14
Injured knee (Right:Left)	24:26
Mean height (m) (SD)	1.72 (0.1)
Mean weight (kg) (SD)	78.1 (14.4)
Mean BMI (kg/m2) (SD)	26.2 (3.8)

ACL: Anterior cruciate ligament; BMI: Body mass index; SD: Standard deviation.

Table 2 Results of knee outcome scores

	Pre-operative (n = 50)	Post-operative (n = 34)
	mean ± SD	mean ± SD
Tegner	3.3 (1.2)	4.1 (0.9)
Lysholm	71.7 (12.8)	85.3 (10.5)
Cincinnati	62.6 (14.7)	75.9 (9.2)
IKDC Sub.	51.5 (17.0)	58.1 (15.6)
KOS-ADLS	71.9 (20.5)	76.5 (14.3)
SF-12 PCS	41.8 (9.1)	43.2 (10.0)
SF-12 MCS	51.3 (9.2)	52.8 (7.9)
KOOS
Symptoms	72.5 (15.1)	71.3 (14.4)
Pain	76.9 (14.4)	77.9 (15.8)
ADL	84.5 (15.1)	87.3 (11.3)
Sp. & Rec.	49.2 (24.9)	43.2 (26.1)
QOL	25.8 (18.7)	39.0 (18.0)
	Mode	Mode
IKDC Exam.	Abnormal	Nearly normal
T&H	Fair	Good

IKDC: International Knee Documentation Committee; Sub: Subjective knee score; Exam: Examination score; KOS-ADLS: Knee Outcome Survey - Activities of Daily Living Scale; SF-12: Short Form - 12 Item Health Survey; PCS: Physical component summary; MCS: Mental component scores; KOOS: Knee Injury and Osteoarthritis Outcome Score; ADL: Activities of daily living; QOL: Quality of life; T&H: Tapper and Hoover Meniscal Grading Score; SD: Standard deviation.

Table 3 Correlations between pre-operative knee outcome scores (n = 50)

Correlation coefficient, P value
	Tegner	Lysholm	Cincinnati	IKDC Sub.	KOS ADLS	SF-12, PCS	SF-12, MCS	KOOS Symp.	KOOS pain	KOOS ADL	KOOS Sp. & Rec.	KOOS QOL
Tegner	-	0.32	0.49	0.47	0.39	0.5	0.12	0.36	0.3	0.26	0.37	0.3
	-	0.023a	< 0.001a	0.001a	0.006a	< 0.001a	0.416	0.013a	0.040a	0.074	0.009a	0.047a
Lysholm	0.32	-	0.83	0.62	0.74	0.49	0.38	0.68	0.64	0.52	0.5	0.55
	0.023a	-	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.007a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a
Cincinnati	0.49	0.83	-	0.66	0.8	0.56	0.37	0.54	0.63	0.58	0.54	0.59
	< 0.001a	< 0.001a	-	< 0.001a	< 0.001a	< 0.001a	0.009a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a
IKDC Sub.	0.47	0.62	0.66	-	0.73	0.65	0.36	0.68	0.69	0.65	0.75	0.63
	< 0.001a	< 0.001a	< 0.001a	-	< 0.001a	< 0.001a	0.011a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a
KOS-ADLS	0.39	0.74	0.8	0.73	-	0.69	0.52	0.72	0.73	0.82	0.65	0.59
	0.006a	< 0.001a	< 0.001a	< 0.001a	-	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a
SF-12, PCS	0.5	0.49	0.56	0.65	0.69	-	0.27	0.63	0.65	0.65	0.6	0.55
	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	-	0.059	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a
SF-12, MCS	0.12	0.38	0.37	0.36	0.52	0.27	-	0.32	0.41	0.47	0.17	0.28
	0.416	0.007a	0.009a	0.011a	< 0.001a	0.059	-	0.024a	0.004a	0.001a	0.247	0.055
KOOS
Symp.	0.36	0.68	0.54	0.68	0.72	0.63	0.32	-	0.79	0.68	0.68	0.47
	0.013a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.024a	-	< 0.001a	< 0.001a	< 0.001a	0.001a
Pain	0.3	0.64	0.63	0.69	0.73	0.65	0.41	0.79	-	0.8	0.61	0.53
	0.040a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.004a	< 0.001a	-	< 0.001a	< 0.001a	< 0.001a
ADL	0.26	0.52	0.58	0.65	0.82	0.65	0.47	0.68	0.8	-	0.64	0.6
	0.074	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	-	< 0.001a	< 0.001a
Sp. & Rec.	0.37	0.5	0.54	0.75	0.65	0.6	0.17	0.68	0.61	0.64	-	0.63
	0.009a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.247	< 0.001a	< 0.001a	< 0.001a	-	< 0.001a
QOL	0.29	0.55	0.59	0.63	0.59	0.55	0.28	0.47	0.53	0.6	0.63	-
	0.047a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.055	0.001a	< 0.001a	< 0.001a	< 0.001a	-

^aStatistically significant at < 0.05 level.

Results of Pearson product moment correlation analysis. IKDC: International Knee Documentation Committee; Sub: Subjective knee score; Exam: Examination score; KOS-ADLS: Knee Outcome Survey - Activities of Daily Living Scale; SF-12: Short Form - 12 Item Health Survey; PCS: Physical component summary; MCS: Mental component scores; KOOS: Knee Injury and Osteoarthritis Outcome Score; ADL: Activities of daily living; QOL: Quality of life; T&H: Tapper and Hoover Meniscal Grading Score; SD: Standard deviation.

Table 4 Correlations between pre-operative knee outcome scores (n = 50)

Correlation coefficient, P value
	Tegner	Lysholm	Cincinnati	IKDC Sub.	KOS ADLS	SF-12, PCS	SF-12, MCS	KOOS Symp.	KOOS pain	KOOS ADL	KOOS Sp. & Rec.	KOOS QOL	IKDC Exam
IKDC Exam.	-0.11	-0.22	-0.31	-0.27	-0.33	-0.17	-0.17	-0.34	-0.23	-0.31	-0.34	-0.23	___
	0.441	0.134	0.032a	0.057	0.020a	0.228	0.251	0.019a	0.109	0.033a	0.017a	0.105	___
T&H	-0.43	-0.67	-0.66	-0.64	-0.61	-0.6	-0.14	-0.63	-0.6	-0.51	-0.54	-0.46	0.17
	0.002a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.351	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.001a	0.243

^aStatistically significant at < 0.05 level.

Results of Spearman rank-order correlation analysis. IKDC: International Knee Documentation Committee; Sub: Subjective knee score; Exam: Examination score; KOS-ADLS: Knee Outcome Survey - Activities of Daily Living Scale; SF-12: Short Form - 12 Item Health Survey; PCS: Physical component summary; MCS: Mental component scores; KOOS: Knee Injury and Osteoarthritis Outcome Score; ADL: Activities of daily living; QOL: Quality of life; SD: Standard deviation.

Table 5 Correlations between post-operative knee outcome scores (n = 34)

Correlation coefficient, P value
	Tegner	Lysholm	Cincinnati	IKDC Sub.	KOS ADLS	SF-12, PCS	SF-12, MCS	KOOS Symp.	KOOS pain	KOOS ADL	KOOS Sp. & Rec.	KOOS QOL
Tegner	-	0.36	0.47	0.51	0.37	0.49	0.35	0.35	0.28	0.38	0.16	0.52
	-	0.037a	0.006a	0.003a	0.032a	0.004a	0.048a	0.044a	0.121	0.028a	0.384	0.002a
Lysholm	0.36	-	0.89	0.71	0.77	0.71	0.32	0.61	0.74	0.72	0.34	0.45
	0.037a	-	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.07	< 0.001a	< 0.001a	< 0.001a	0.053	0.009a
Cincinnati	0.47	0.89	-	0.87	0.91	0.78	0.39	0.73	0.82	0.85	0.48	0.63
	0.006a	< 0.001a	-	< 0.001a	< 0.001a	< 0.001a	0.025a	< 0.001a	< 0.001a	< 0.001a	0.004a	< 0.001a
IKDC Sub.	0.51	0.71	0.87	-	0.84	0.77	0.47	0.74	0.74	0.81	0.59	0.71
	0.003a	< 0.001a	< 0.001a	-	< 0.001a	< 0.001a	0.006a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a
KOS-ADLS	0.37	0.77	0.91	0.84	-	0.75	0.45	0.82	87	0.86	0.59	0.64
	0.032a	< 0.001a	< 0.001a	< 0.001a	-	< 0.001a	0.008a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a
SF-12, PCS	0.49	0.71	0.78	0.77	0.75	-	0.25	0.57	0.72	0.83	0.47	0.62
	0.004a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	-	0.16	0.001a	< 0.001a	< 0.001a	0.005a	< 0.001a
SF-12, MCS	0.35	0.32	0.39	0.47	0.45	0.25	-	0.56	0.45	0.48	0.18	0.44
	0.048a	0.07	0.025a	0.006a	0.008a	0.16	-	0.001a	0.008a	0.004a	0.288	0.010a
KOOS
Symp.	0.35	0.61	0.73	0.74	0.82	0.57	0.56	-	0.75	0.69	0.61	0.58
	0.044a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.001a	0.001a	-	< 0.001a	< 0.001a	< 0.001a	< 0.001a
Pain	0.28	0.74	0.82	0.74	0.87	0.72	0.45	0.75	-	0.86	0.56	0.53
	0.121	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.008a	< 0.001a	-	< 0.001a	0.001a	0.001a
ADL	0.38	0.72	0.85	0.81	0.86	0.83	0.48	0.69	0.86	-	0.55	0.54
	0.028a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.004a	< 0.001a	< 0.001a	-	0.001a	0.001a
Sp. & Rec.	0.16	0.34	0.48	0.59	0.59	0.47	0.19	0.61	0.56	0.55	-	0.45
	0.384	0.053	0.004a	< 0.001a	< 0.001a	0.005a	0.288	< 0.001a	0.001a	0.001a	-	0.008a
QOL	0.52	0.45	0.63	0.71	0.64	0.62	0.44	0.58	0.53	0.54	0.45	-
	0.002a	0.009a	< 0.001a	< 0.001a	< 0.001a	< 0.001a	0.010a	< 0.001a	0.001a	0.001a	0.008a	-

^aStatistically significant at < 0.05 level.

Results of Pearson product moment correlation analysis. IKDC: International Knee Documentation Committee; Sub: Subjective knee score; KOS-ADLS: Knee Outcome Survey - Activities of Daily Living Scale; SF-12: Short Form - 12 Item Health Survey; PCS: Physical component summary; MCS: Mental component scores; KOOS: Knee Injury and Osteoarthritis Outcome Score; ADL: Activities of daily living; QOL: Quality of life; SD: Standard deviation.

Table 6 Correlations between post-operative knee outcome scores (n = 34)

Correlation coefficient, P value
	Tegner	Lysholm	Cincinnati	IKDC Sub.	KOS ADLS	SF-12, PCS	SF-12, MCS	KOOS Symp.	KOOS pain	KOOS ADL	KOOS Sp. & Rec.	KOOS QOL	IKDC Exam
IKDC Exam.	-0.34	-0.3	-0.39	-0.42	-0.35	-0.39	0.02	-0.17	-0.35	-0.35	-0.36	-0.38	-
	0.056	0.095	0.024a	0.016a	0.044a	0.024a	0.93	0.324	0.044a	0.043a	0.035a	0.025a	-
T&H	-0.51	-0.62	-0.55	-0.61	-0.63	-0.6	-0.55	0.66	-0.62	-0.59	-0.45	-0.61	0.2
	0.002a	< 0.001a	0.001a	< 0.001a	< 0.001a	< 0.001a	0.001a	< 0.001a	< 0.001a	< 0.001a	0.009a	< 0.001a	0.26

^aStatistically significant at < 0.05 level.

Results of Spearman rank-order correlation analysis. IKDC: International Knee Documentation Committee; Sub: Subjective knee score; Exam: Examination score; KOS-ADLS: Knee Outcome Survey - Activities of Daily Living Scale; SF-12: Short Form - 12 Item Health Survey; PCS: Physical component summary; MCS: Mental component scores; KOOS: Knee Injury and Osteoarthritis Outcome Score; ADL: Activities of daily living; QOL: Quality of life; T&H: Tapper and Hoover Meniscal Grading Score; SD: Standard deviation.

Table 7 Multiple linear regression analysis of pre-operative knee outcome scores (n = 50)

Equation (R2, P value, σE)
KOOS
Tegner = 2.3 + (0.02 × Symp.) + (0.003 × Pain) - (0.01 × ADL) + (0.01 × Sp. & Rec.) + (0.01 × QOL)
(R2 = 0.17, P = 0.161, σE = 1.2)
Lysholm = 38.2 + (0.36 × Symp.) + (0.22 × Pain) - (0.14 × ADL) - (0.05 × Sp. & Rec.) + (0.20 × QOL)
(R2 = 0.55, P < 0.001, σE = 9.0)
Cincinnati = 27.0 + (0.02 × Symp.) + (0.36 × Pain) + (0.02 × ADL) + (0.05 × Sp. & Rec.) + (0.21 × QOL)
(R2 = 0.49, P < 0.001, σE = 10.9)
IKDC Subjective = 12.6 + (0.11 × Symp.) + (0.25 × Pain) - (0.002 × ADL) + (0.23 × Sp. & Rec.) + (0.14 × QOL)
(R2 = 0.68, P < 0.001, σE = 9.1)
KOS-ADLS = (0.29 × Symp.) + (0.01 × Pain) + (0.64 × ADL) + (0.05 × Sp. & Rec.) + (0.09 × QOL) – 6.4
(R2 = 0.74, P <0.001, σE = 10.3)
SF-12
Tegner = 0.6 + (0.07 × PCS) - (0.002 × MCS)
(R2 = 0.25, P = 0.002, σE = 1.1)
Lysholm = 30.6 + (0.61 × PCS) + (0.33 × MCS)
(R2 = 0.30, P = 0.002, σE = 10.7)
Cincinnati = 14.4 + (0.83 × PCS) + (0.33 × MCS)
(R2 = 0.36, P < 0.001, σE = 11.7)
IKDC Subjective = (1.18 × PCS) + (0.32 × MCS) - 12.2
(R2 = 0.46, P < 0.001, σE = 12.7)
KOS-ADLS = (1.29 × PCS) + (0.65 × MCS) - 12.8
(R2 = 0.59, P < 0.001, σE = 12.2)

R²: Regression coefficient; σ_E: Root mean squared error. IKDC: International Knee Documentation Committee; Sub: Subjective knee score; KOS-ADLS: Knee Outcome Survey - Activities of Daily Living Scale; SF-12: Short Form - 12 Item Health Survey; PCS: Physical component summary; MCS: Mental component scores; KOOS: Knee Injury and Osteoarthritis Outcome Score; ADL: Activities of daily living; QOL: Quality of life.

Table 8 Multiple linear regression analysis of post-operative knee outcome scores (n = 34)

Equation (R2, P value, σE)
KOOS
Tegner = 1.2 + (0.01 × Symp.) - (0.02 × Pain) + (0.04 × ADL) - (0.01 × Sp. & Rec.) + (0.02 × QOL)
(R2 = 0.33, P =0.042, σE = 0.8)
Lysholm = 31.6 + (0.12 × Symp.) + (0.29 × Pain) + (0.28 × ADL) - (0.08 × Sp. & Rec.) + (0.02 × QOL)
(R2 = 0.60, P < 0.001, σE = 7.2)
Cincinnati = 20.9 + (0.12 × Symp.) + (0.14 × Pain) + (0.39 × ADL) - (0.04 × Sp. & Rec.) + (0.09 × QOL)
(R2 = 0.80, P < 0.001, σE = 4.5)
IKDC Subjective = (0.23 × Symp.) - (0.07 × Pain) + (0.69 × ADL) + (0.05 × Sp. & Rec.) + (0.27 × QOL) - 26.5
(R2 = 0.79, P < 0.001, σE = 7.9)
KOS-ADLS = (0.29 × Symp.) + (0.25 × Pain) + (0.42 × ADL) + (0.000009 × Sp. & Rec.) + (0.11 × QOL) – 5.4
(R2 = 0.87, P < 0.001, σE = 5.6)
SF-12
Tegner = 0.8 + (0.04 × PCS) + (0.03 × MCS)
(R2 = 0.30, P = 0.005, σE = 0.8)
Lysholm = 44.4 + (0.70 × PCS) + (0.20 × MCS)
(R2 = 0.52, P < 0.001, σE = 7.5)
Cincinnati = 34.1 + (0.67 × PCS) + (0.24 × MCS)
(R2 = 0.65, P < 0.001, σE = 5.6)
IKDC Subjective = (1.07 × PCS) + (0.58 × MCS) - 18.8
(R2 = 0.68, P < 0.001, σE = 9.2)
KOS-ADLS = 7.9 + (0.97 × PCS) + (0.51 × MCS)
(R2 = 0.65, P < 0.001, σE = 8.8)

R²: Regression coefficient; σ_E: Root mean squared error. IKDC: International Knee Documentation Committee; Sub: Subjective knee score; KOS-ADLS: Knee Outcome Survey - Activities of Daily Living Scale; SF-12: Short Form - 12 Item Health Survey; PCS: Physical component summary; MCS: Mental component scores; KOOS: Knee Injury and Osteoarthritis Outcome Score; ADL: Activities of daily living; QOL: Quality of life.