Femoro Patella Vialla patellofemoral arthroplasty: An independent assessment of outcomes at minimum 2-year follow-up

Table 1 Previous surgery in 41 knees

Previous surgery	No. of knees (% of total)
Arthroscopy	3 (7)
Tibial tuberosity transfer	2 (5)
Medial patellofemoral ligament reconstruction	2 (5)
No intervention	34 (83)
Total	41 (100)

Table 2 Effect of different patient characteristics on outcome

Patient factor	Category	n	Median OKS (Q1, Q3)	P value	Mean Melbourne Score (SD)	P value
Sex	Male	12	42 (38, 46)	0.28	21.3 (4.7)	0.31
	Female	29	40 (37, 42)		19.1 (6.4)
Trochlear dysplasia	Non-dysplastic	10	41 (36, 43)	0.95	20.0 (5.7)	0.67
	Dysplastic	31	41 (38, 43)		19.0 (7.1)
Patella alta	Yes	21	41 (37, 42)	0.56	19.3 (6.4)	0.65
	No	20	40 (36, 44)		20.2 (5.6)
Uni- or bi-lateral	Unilateral	19	41 (37, 42)	0.83	19.8 (5.6)	0.97
	Bilateral	22	41 (37, 43)		19.7 (6.4)
Previous surgery	Yes	10	40 (37, 42)	0.70	22.0 (5.0)	0.28
	No	31	41 (37, 43)		19.0 (6.1)

OKS: Oxford Knee Score.

Table 3 A comparison of our results with those previously published for patellofemoral arthroplasty and total knee replacement for isolated patellofemoral arthritis

Ref.	Implant	Number knees/patients	Mean age (yr)	Mean follow-up (yr)	OKS	Melbourne Score	Patient satisfaction	Trochlear dysplasia	Complications	Further operations
Dalury[23]	TKR	33/25	70	5.2	NR	NR	100%	NR	NR	0
Ackroyd et al[3]	AVON	109/85	68	5.0	39	25	80%	NR	4 superficial infections 2 stiffness	4 (4.2%) conversions to TKR
Starks et al[4]	AVON	37/29	66	2.0	39	28	86%	NR	1 patella fracture 1 patella resurfacing	1 (2.7%) patella resurfacing
Al-Hadithy et al[22]	FPV	49/41	62	3.0	38	NR	NR	NR	1 scar pain	3 (6%); 2 (4%) to TKR
Williams et al[10]	FPV	48/48	63	2.1	NR	NR	NR	Trochlear dysplasia associated with less revision	10 persistent pain 1 infection, 1 fracture, 1 hypertrophic scar	7 (15%); 5 to TKR
The present report	FPV	41/31	65	3.2	40	21	78%	84% of cases had trochlear dysplasia preoperatively No difference in outcomes	2 superficial infections: Treated with oral antibiotics	1 (2%) conversion to TKR. No lateral releases

NR: Not recorded; OKS: Oxford Knee Score; FPV: Femoro-Patella Vialla; TKR: Total knee replacement.