Similar postoperative patient-reported outcome in both second generation patellofemoral arthroplasty and total knee arthroplasty for treatment of isolated patellofemoral osteoarthritis: a systematic review

Abstract

Introduction

Due to inconsistent results and high failure rates, total knee arthroplasty (TKA) is more often used to treat isolated patellofemoral osteoarthritis (PFOA) despite the theoretical advantage of patellofemoral arthroplasty (PFA). It is perceived that second-generation PFA may have improved the outcomes of surgery. In this systematic review, the primary aim was to compare outcomes of second-generation PFA and TKA by assessment of patient-reported outcome measures (PROMs).

Methods

A systematic search was made in PubMed, Medline, Embase, Cinahl, Web of Science, Cochrane Library and MeSH to identify studies using second-generation PFA implants or TKA for treatment of PFOA. Only studies using The American Knee Society (AKSS), The Oxford Knee Score (OKS) or The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to report on PROMs were included.

Results

The postoperative weighted mean AKSS knee scores were 88.6 in the second-generation PFA group and 91.8 in the TKA group. The postoperative weighted mean AKSS function score was 79.5 in the second-generation PFA group and 86.4 in the TKA group. There was no significant difference in the mean AKSS knee or function scores between the second-generation PFA group and the TKA group. The postoperative weighted mean OKS score was 36.7 and the postoperative weighted mean WOMAC score was 24.4. The revision rate was higher in the second-generation PFA group (113 revisions [8.4%]) than in the TKA group (3 revisions [1.3%]). Progression of OA was most commonly noted as the reason for revision of PFA, and it was noted in 60 cases [53.1%]; this was followed by pain in 33 cases [29.2%].

Conclusion

Excellent postoperative weighted mean AKSS knee scores were found in both the second-generation PFA group and in the TKA group, suggesting that both surgical options can result in a satisfying patient-reported outcome. Higher revision rates in the second-generation PFA studies may in part be due to challenges related to patient selection. Based on evaluation of PROMs, the use of second-generation PFA seems to be an equal option to TKA for treatment of isolated PFOA in appropriately selected patients. Hopefully, this can be considered by physicians in their daily clinical work.

Level of evidence

IV.

Appendix

Study	Inclusion criteria	Exclusion criteria
Second-generation (2G) PFA
Osarumwense et al. [32]	Degenerative PFOA	Active infection
	Unresponsive to non-surgical options	Inflammatory arthropathy
	Post-traumatic	Tibiofemoral degenerative changes
	Grade 3 chondrosis	Fixed joint deformities
	Failed previous extensor unloading procedure	Uncorrected patellofemoral instability or malalignment
	Malalignment/dysplasia-induced degeneration with or without instability
Romagnoli et al. [33]	Isolated PFOA (radiographically: Iwano ≥ 2)	Osteoarthritis in tibiofemoral compartments
	-Post-traumatic	Clinically instable knee in frontal/sagittal plane
	-Dysplasia/malalignment	ROM < 90°
	Absence of tibiofemoral osteoarthritis (Kellgren/Lawrence ≤ 2)	Flexion contracture > 10°
		Inflammatory disease
Ahearn et al. [13]	Isolated PFOA (clinically)	Tibiofemoral osteoarthritis
	Intact cruciate ligaments	Inflammatory arthritis
	Previous realignment procedure
	Fixed flexion deformity up to 10°
Liow et al. [25]	Degenerative PFOA	Tibiofemoral osteoarthritis (Kellgren grade 2)
	Unresponsive to non-surgical options	Advanced chondromalacia
	Post-traumatic	Systematic inflammatory arthritis
	Grade 3 chondrosis	Regional pain syndrome
	Failed previous extensor unloading procedure	Infection/previous history of severe arthrofibrotic healing
	Malalignment/dysplasia-induced degeneration with or without instability
Akhbari et al. [14]	Isolated PFOA (clinically, radiographically, arthroscopic)	Localized chondral lesions > 10 mm in areas other than PFJ
	Fixed flexion deformity up to 10°
Goh et al. [22]	Isolated PFOA (radiographically)	Advanced chondromalacia
	Normal tibiofemoral joint (radiographically, arthroscopic)	Systematic inflammatory arthritis
	Post-traumatic	Regional pain syndrome
	Malalignment/dysplasia	Infection/previous history of severe arthrofibrotic healing
	Previous failed procedures	Q angle: females > 20°, males > 20°
Benazzo et al. [17]	Isolated PFOA (clinically, radiographically)	Remarkable tibiofemoral osteoarthritis
	-Primary	Systematic joint disease
	-Degenerative due to malalignment/dysplasia	Patella baja
	-Post-traumatic	ROM not full
		Uncorrected tibiofemoral malalignment
Williams et al. [37]	Isolated PFOA (radiographically: Lawrence/Kellgren)	None reported
	Trochlear dysplasia
Hernigou et al. [23]	Isolated PFOA, degenerative	None reported
	-Associated with extensor mechanism instability due to trochlear dysplasia
	-Failed conservative surgery
Al-Hadithy et al. [15]	Isolated PFOA (clinically, radiographically, arthroscopic)	Chondral lesions > 10 mm in areas other than PFJ
		Fixed flexion deformities > 10° or < 90°
Davies et al. [20]	Isolated PFOA (clinically, radiographically, arthroscopic)	None reported
Morris et al. [29]	Advanced PFOA	Tibiofemoral osteoarthritis
	Post-traumatic PFOA	Advanced chondromalacia/chondrocalcinosis
	Advanced chondromalacia of the patella or trochlear	Systematic inflammatory arthritis
	Tibiofemoral Ählback scores ≤ 1	Complex regional pain syndrome
	Severe symptoms affecting daily activity	Infection
		Uncorrected Q angle: Female > 20°, Male > 15°
Mont et al. [28]	Degenerative PFOA	TFOA Kellgren grade 2
	Unresponsive to non-surgical options	Systematic inflammatory arthropathy
	Post-traumatic	Chondrosis < grade 3 or 4
	Grade 3 chondrosis	Patella infera
	Failed previous extensor unloading procedure	Uncorrected TF instability/malalignment (valgus > 8°, varus > 5°)
	Malalignment/dysplasia-induced degeneration with or without instability	Active infection
		Chronic regional pain syndrome
		Fixed ROM loss
Beitzel et al. [16]	Isolated PFOA (Kellgren grade 3–4)	High-grade tibiofemoral osteoarthritis
		Inflammatory or systemic diseases
		Autoimmune diseases
		Psychiatric conditions
		Imprisonment
		Pregnancy
Mofidi et al. [26]	Isolated PFOA (clinically, radiographically)	None reported
	-Primary
	-Post-traumatic
	-Secondary to patellar instability
Monk et al. [27]	Isolated PFOA (clinically, radiographically)	None reported
Charalambous et al. [19]	Isolated PFOA (radiographically, operation)	Inflammatory arthritis
	Superficial chondral damage at tibiofemoral articulation
Sarda et al. [34]	Isolated PFOA (radiographically, arthroscopic)	Varus, valgus deformity > 4°
	Normal tibiofemoral joint (radiographically)	Flexion deformity > 5° or < 100°
	No significant varus/valgus malalignment
Odumenya et al. [31]	Isolated PFOA (radiographically)	Chondral lesions > 10 mm in other areas than PFJ
	-Primary	Fixed flexion deformities
	-Post-traumatic
Gao et al. [21]	Isolated PFOA (clinically, radiographically, arthroscopic)	None reported
Butler and Shannon [18]	Isolated PFOA	None reported
	-Primary
	-Post-traumatic
	-Previous patellar dislocation
	Minimal maltracking other patella
	No significant varus/valgus deformity
Starks et al. [36]	Isolated PFOA (clinically, radiographically, arthroscopic)	None reported
Leadbetter et al. [24]	Degenerative PFOA	TFOA Kellgren grade 2
	Unresponsive to non-surgical options	Systematic inflammatory arthropathy
	Post-traumatic	Chondrosis < grade 3 or 4
	Grade 3 chondrosis	Patella infera
	Failed previous extensor unloading procedure	Uncorrected TF instability/malalignment (valgus > 8°, varus > 5°)
	Malalignment/dysplasia-induced degeneration with or without instability	Active infection
		Chronic regional pain syndrome
		Fixed ROM loss
Ackroyd et al. [12]	Isolated PFOA (radiographically)	Algodystrophy
	Normal tibiofemoral Joint (radiographically, arthroscopic)	Regional pain syndrome
	No significant varus/valgus malalignment	Patella infera
		Fixed flexion deformity
Sisto and Sarin [35]	Isolated PFOA (clinically, radiographically)	Medial/lateral advanced arthritis (Ählback score > 1)
Nicol et al. [30]	Isolated PFOA (radiographically)	None reported
	-Primary
	-Post-traumatic
	Recurrent patellofemoral joint dislocation
	+/− trochlear dysplasia
Ackroyd et al. [11]	Isolated PFOA (radiographically)	Algodystrophy
	Normal tibiofemoral Joint (radiographically, arthroscopic)	Regional pain syndrome
	No significant varus/valgus malalignment	Patella infera
		Fixed flexion deformity
TKA
Meding et al. [40]	Isolated PFOA (radiologically)	None reported
	Minimal tibiofemoral changes
Dalury et al. [38]	Isolated PFOA (radiographically)	None reported
	≤ Grade 2 chondromalacia in tibiofemoral joint
Mont et al. [41]	Isolated PFOA (clinically, radiographically: Ahlbäck)	Previous procedures involving the knee
		Ahlbäck > 1 in medial, lateral compartment
Parvizi et al. [42]	Isolated PFOA (clinically, radiographically)	None reported
	None/mild degenerative disease involving the radial/lateral compartment
Thompson et al. [43]	Isolated PFOA (clinically, radiographically: Spernes)	None reported
	Minimal tibiofemoral osteoarthritis (Kellgren/Lawrence ≤ 2)
Laskin and van Steijn [39]	Isolated PFOA (clinically, radiographically)	Fixed valgus, varus deformity
	Minimal tibiofemoral degenerative changes
Comparing 2G PFA and TKA
Odgaard et al. [45]	Isolated PFOA (clinically, radiographically)	< 18 Years
		Psychiatric conditions
		Not understanding oral/written information
		Alcohol/drug abuse
		Disseminated malignant disease
		Severe neurological disease
		Symptomatic hip or back condition
		Rheumatoid arthritis
		Non-Danish citizenship
		Tibiofemoral osteoarthritis (Kellgren/Lawrence 3–4, Ahlbäck 1–5)
		> 5° Malalignment clinically
		Sagittal or coronal instability
		Patella infera
		Patella alta
		Complex regional pain syndrome
		Previous arthrofibrosis
Dahm et al. [44]	Isolated PFOA (radiographically: Kellgren/Lawrence ≤ 2 and Iwano ≥ 2)	None reported