Internal rotational patellar resection and patella alta induced patellar maltracking in total knee arthroplasty: intraoperative measurement of the patellofemoral pressure

Table 6 Correlations between the radiographic parameters and the lateral PFP of the RPK phase

	Lateral PFP of the resurfaced patella and knee phase (N)^†
	0° knee flexion		90° knee flexion		120° knee flexion		135° knee flexion
	rs	p value	rs	p value	rs	p value	rs	p value
Parameters of postoperative radiographs
HKA (°)	−0.30	n.s.	0.01	n.s.	−0.02	n.s.	−0.02	n.s.
LDFA (°)	0.39	0.010*	−0.01	n.s.	0.05	n.s.	0.08	n.s.
MPTA (°)	−0.22	n.s.	0.24	n.s.	0.21	n.s.	0.24	n.s.
AFO (mm)	−0.04	n.s.	0.29	n.s.	0.16	n.s.	0.10	n.s.
ISR	−0.08	n.s.	0.34	0.030*	0.37	0.018*	0.30	0.053
PT^† (°)	0.14	n.s.	0.14	n.s.	0.14	n.s.	0.15	n.s.
PRA (°)	0.18	n.s.	−0.24	n.s.	−0.47	0.0015*	−0.40	0.0078*

AFO anterior femoral offset, FT favorable patellar tracking, HKA hip–knee–ankle angle, ISR Insall–Salvati ratio, IT impaired patellar tracking, LDFA lateral distal femoral angle, LRR lateral retinacular release, MPTA medial proximal tibial angle, PFP patellofemoral pressure, PRA patellar resection angle, PT patellar tilt, RPK resurfaced patella and knee, n.s. not significant, rs Spearman’s rank correlation coefficients
^aWith regard to PT, correlation was evaluated with the lateral PFP of the RPK phase for the FT group and the lateral PFP of post-LRR phase for the IT group
Significant p values at this threshold are marked with an asterisk

ISSN: 2234-2451