Table 2.

Diagnostic utility of self-reported pain in identifying PFJ damage (comparing knees with isolated PFJ full-thickness cartilage damage or BML to knees with either isolated TJF or no full-thickness cartilage damage or BML).

		Prevalence	Sensitivity	Specificity	LR+	PPV	NPV
AKP	Any	53	60	53	1.3	53	59
AKP	Isolated	23	27	81	1.4	57	55
Max pain with stairs (up or down)	(≥ min)	70	74	33	1.1	50	58
Max pain with stairs (up or down)	(≥ mod)	35	40	70	1.3	54	56
Pain going up stairs	(≥ min)	69	72	34	1.1	49	57
Pain going up stairs	(≥ mod)	30	35	74	1.3	54	56
Pain going down stairs	(≥ min)	62	64	40	1.1	49	55
Pain going down stairs	(≥ mod)	25	32	80	1.6	59	57
Absence of pain walking on level ground	(≥ min)	57	58	44	1.0	48	54
Absence of pain walking on level ground	(≥ mod)	90	93	13	1.1	49	68
Any AKP + max pain with stairs	(≥ min)	42	49	64	1.4	56	58
Any AKP + max pain with stairs	(≥ mod)	23	29	82	1.6	60	56
Any AKP + absence of pain walking on level ground	(≥ min)	27	30	76	1.3	52	54
Any AKP + absence of pain walking on level ground	(≥ mod)	47	56	60	1.4	56	60
Isolated AKP + max pain with stairs	(≥ min)	15	20	90	2.0	63	55
Isolated AKP + max pain with stairs	(≥ mod)	6	9	97	3.0	72	54
Isolated AKP + absence of pain walking on level ground	(≥ min)	16	20	86	1.4	57	54
Isolated AKP + absence of pain walking on level ground	(≥ mod)	22	26	82	1.4	57	55

LR+: positive likelihood ratio (Sn/1-Sp); PPV: positive predictive value; NPV: negative predictive value; AKP: anterior knee pain; max: maximum; min: minimal; mod: moderate; PFJ: patellofemoral joint; TFJ: tibiofemoral joint; BML: bone marrow lesions.