Abstract
Aims
With up to 40% of patients having patellofemoral joint osteoarthritis (PFJ OA), the two arthroplasty options are to replace solely the patellofemoral joint via patellofemoral arthroplasty (PFA), or the entire knee via total knee arthroplasty (TKA). The aim of this study was to assess postoperative success of second-generation PFAs compared to TKAs for patients treated for PFJ OA using patient-reported outcome measures (PROMs) and domains deemed important by patients following a patient and public involvement meeting.
Methods
MEDLINE, EMBASE via OVID, CINAHL, and EBSCO were searched from inception to January 2022. Any study addressing surgical treatment of primary patellofemoral joint OA using second generation PFA and TKA in patients aged above 18 years with follow-up data of 30 days were included. Studies relating to OA secondary to trauma were excluded. ROB-2 and ROBINS-I bias tools were used.
Results
A total of nine studies were included, made up of four randomized controlled trials (domain 1) and five cohort studies (domain 2). PROMs and knee function specific scores developed for reporting TKA were unable to detect any difference between PFA and TKA. There was no significant difference in complications between PFA and TKA. PFAs were found to have a better postoperative range of motion.
Conclusion
TKA and PFA are both viable options for patients with primary PFJ OA. Over time, we have seen an emphasis on patient satisfaction and better quality of life. Recommending sacrificing healthy medial and lateral compartments to treat patellofemoral joint arthritis should be given further thought.
Cite this article: Bone Jt Open 2023;4(12):948–956.
Take home message
Patellofemoral joint arthroplasty (PFA) is associated with fewer complications than total knee arthroplasty.
PFA surgery should be included as an option in the shared decision-making process between clinicians.
The review gives an insight to the treatment available for those young active patellofemoral joint osteoarthritic patients.
Introduction
Isolated patellofemoral joint osteoarthritis (PFJ OA) is common, with up to 40% of patients having the disease isolated to the patellofemoral compartment.1,2 Between 13.5% and 23.6% of patients with PFJ OA present with symptomatic anterior knee pain, which is the most common condition seen in a general knee clinic.3,4 The knee pain typically occurs on standing from a seated position, stair climbing, or kneeling.5 Patients presenting with anterior knee pain are typically young and active who have higher demands on their knee than those with generalized disease.5 Females are twice as likely to develop PFJ OA than males.6 Once nonoperative treatment is exhausted, the two arthroplasty options are to replace solely the patellofemoral joint via patellofemoral arthroplasty (PFA), or the entire knee with total knee arthroplasty (TKA).7,8 In PFA, only the patellofemoral joint is resurfaced, preserving the cruciate ligaments, and the unaffected tibiofemoral joint surfaces; it is relatively bone conserving compared to TKA.7-10 This has the potential advantages of being a safer surgical approach with less blood loss, a faster recovery, and a lower chance of early complications, as well as restoring more normal kinematic and proprioception.11
PFAs and TKAs are both effective in alleviating pain in patients with PFJ OA. With a mean of 52 TKA cases per surgeon per annum compared to 3.7 PFA cases per surgeon per annum, surgical outcomes following TKA may be reproducible.12 The absence of a difference in Oxford Knee Score (OKS)13 at the first year of surgery between PFAs and TKAs, and the low TKA revision rate of 2.66% compared to a 9.8% risk of PFA revision at five years, may explain why PFA use rate remains at less than 1% within the UK National Joint Registry.14,15 With partial knee arthroplasty associated with a higher risk of revision compared to TKA, it is reasonable to assume that surgeons prefer to maintain their low revision status by using a procedure that is less likely to require revision than partial arthroplasty, even if the patient’s function may be better with the partial arthroplasty.16,17
Revisions of PFAs can be early (normally due to patella maltracking, subluxation, dislocation, or instability) or in the mid to long term due to progression of OA.18 With all these risks and without clear indications, surgeons remain unsure which patients to offer a PFA to.19 Patients with trochlear dysplasia or patella alta have demonstrated less progression of tibiofemoral OA compared to those without, but have a higher incidence of early complications due to difficulties in restoring normal patella tracking and stability.20-23 Therefore, careful patient selection and measurement of the right outcome measures, which are patient-important, remains paramount.19,24-26
The purpose of this systematic review is to compare the outcome of PFA and TKA using implants in current clinical use to help the patient and clinician make an informed decision on treatment. The outcomes of interest are clinical outcomes (including patient-reported outcome measures (PROMs), range of motion (ROM), and pain levels), complications, implant survival, and length of stay.
Methods
The methods used in this review were specified in advance, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and is registered on PROSPERO (CRD42020182597).27 Due to the heterogeneity of the literature on this topic, we have performed the analysis in two sections: studies from randomized controlled trials (RCTs; domain 1), and studies from cohort studies (domain 2).
Data sources and searches
A comprehensive search strategy was created and designed to capture all relevant articles pertaining to surgical treatment for PFJ OA. The search strategy was applied to the following databases from inception until April 2023: MEDLINE, EMBASE via OVID, CINAHL, and EBSCO. The full search strategy is detailed in the Supplementary material.
Inclusion/exclusion criteria
The inclusion and exclusion criteria were defined during the protocol stage. Any prospective RCT, cohort study (retrospective and prospective), or registry-based study addressing surgical treatment of PFJ OA using second-generation PFA and TKA in patients aged above 18 years were included. Studies were only restricted to primary OA and those related to OA secondary to trauma were excluded. Studies defined PFJ OA using radiological or coding methods have been outlined in Supplementary Table i. For studies to be included, a minimum follow-up of 30 days was necessary, and if studies reported PROM scores at a minimum of six months and up to two years following the procedure. Due to the small number of cohort studies that compared PFA and TKA directly, no minimum sample size was set.
Selection of studies
Two authors (MVB, JW) scanned titles and abstracts for relevance, and full texts were evaluated against the eligibility criteria. Reference lists of all the studies identified in the above methods were screened for additional studies of possible relevance. Final consensus on inclusion was reached between the authors. The two reviewers (MVB, JW) independently extracted data using a specifically designed standardized data extracting form and the extracted data afterwards was compared for consistency. All inconsistencies between the two forms were resolved by discussion between the two data extractors. Any disagreement between the data extractors after the initial discussion related to inconsistencies between the two individual data extractions were solved involving a third person (ADL).
Data extraction
The same two authors independently extracted data using a customised data extraction form on Excel (Microsoft, USA) to record intervention, patient characteristics, inclusion criteria, exclusion criteria, outcomes, and results. Patient characteristics included sample size, mean age, and sex. Any discrepancies were resolved by discussion until 100% consensus was reached. If complete data were not available from full text articles, the authors were contacted to provide this information. If the authors did not respond following a subsequent email, the study was excluded from data synthesis.
Outcomes
Outcome measures included:
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PROMs.
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Implant survival measured in terms of all-cause revision rate at five and ten years.
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Complications which (venous thromboembolism, wound infection, or patella issues requiring a reoperations rather than revision).
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ROM.
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Length of stay.
The PROM scores of included studies were recorded at the greatest possible time point. WOMAC scores28 and articles using the ‘old’ OKS were transformed so a higher score reflected a better outcome.29
Risk of bias assessment
We conducted a risk of bias assessment using ROB-2 for RCTs and ROBINS-I for non-randomized interventions (Supplementary Tables ii and iii) .30,31 Three independent coders (MVB, BS, SC) assessed study quality and any disagreements were resolved via discussion to reach a final decision. The studies were then classified into overall low, medium, and high, based on the scoring protocol of the instruments.
Data analysis
When possible, inverse variance weighted random effects meta-analysis were performed. Individual relative risk estimates and summary data were displayed graphically in forest plots using RevMan 5.4 (The Cochrane Collaboration, UK). Heterogeneity was determined according to Cochrane interpretation (I2 > 75% associate with considerable heterogeneity). A narrative interpretation was performed if limited data was available. Data from the different research methodologies were presented in their respective sections as outlined previously.
Patient and public involvement
A patient and public involvement (PPI) meeting took place on the 28 October 2020, where patients were engaged by social media to consult the authors on which patient outcomes were most relevant to them as patients, with questions such as, ‘What are the most important factors in the recovery process for a patient?’. They expressed a preference to know all surgical treatment options available and all respective risks. This helped us to formulate a research question and determine which outcomes to compare. According to the patients attending the PPI group, they would rather opt for smaller, safer, and successful operation rather than larger surgeries. Patients were not asked to advise on study methodology and interpretation. Patients were briefed about the results, but were not involved in result dissemination.
Results
As shown in Figure 1, of 1,514 imported, 177 proceeded with full text eligibility. There were four RCTs (domain 1) and five observational studies (domain 2).11,15,32-38 The remainder were excluded due to study design and therefore did not meet the inclusion criteria. Level 4 evidence was not included due to absence of controls, which introduce a high level of bias.39
Fig. 1
Flowchart of studies review and included for analysis.
Patient-reported outcomes
Studies measured outcomes in terms of knee function using different mean or median scores (Knee injury and Osteoarthritis Outcome Score (KOOS),40 KOOS-Physical Function, University of California, Los Angeles Activity Scale (UCLA),41 Tegner Activity Scale,42 OKS, Knee Society Score (KSS),43 36-Item Short-Form Health Survey (SF-36) questionnaire,44 EuroQol five-dimension questionnaire (EQ-5D),45 and Western Ontario and McMaster Universities osteoarthritis index (WOMAC))28 made comparisons challenging.
In terms of OKS, from a total of six studies with a population size of 455 individuals, there was a trend to better OKS scores after PFA than TKA, but the OKS was not able to detect any clinically significant difference in knee function in both domains 1 and 2 (Figure 2). Data presented from three RCTs (domain 1) and three cohort studies (domain 2) show a mean difference of 0.34 (95% confidence interval (CI) -1.69 to 2.37) and mean difference of -2.96 (95% CI -7.16 to 1.24), respectively.
Fig. 2
Forest plot comparing Oxford Knee Score after patellofemoral arthroplasty (PFA) versus total knee arthroplasty (TKA). CI, confidence interval; IV, inverse variance weighting.
Function scores
A total of five studies comparing functional scores between both surgical treatments were pooled into a forest plot (Figure 3).15,35-38,46
Fig. 3
Forest plot comparing knee function specific scores after patellofemoral arthroplasty (PFA) versus total knee arthroplasty (TKA). CI, confidence interval; IV, inverse variance weighting; KOOS, Knee injury and Osteoarthritis Outcome Score; WOMAC, Western Ontario and McMaster Universities osteoarthritis index.
In this analysis, there was no statistically significant difference in knee function between either surgical treatment in both domains 1 and 2. In domain 1, the data showed a standard mean difference of -0.10 (95% CI -0.15 to 0.35). Studies from domain 2 had a standard mean difference of -0.11 (95% CI -0.43 to 0.22).
Range of motion
Two studies reported ROM following a PFA and TKA procedure.11,15 From a study of 18 PFAs and 22 TKAs, PFAs were found to have better ROM postoperatively when compared to TKA, with a gain of 4⁰ of flexion. This was further supported by Odgaard et al,15 where results were PFA patients are more likely to their preoperative ROM unlike their TKA counterparts.
Length of stay
Two studies reported length of stay in their results in domains 1 and 2.11,15 There was no significant difference in domain 1; however, domain 2 showed that PFAs have shorter postoperative stays with a mean duration of 3.3 days compared to 4.4 days following a TKA procedure (Figure 4).11,15
Fig. 4
Forest plot comparing length of stay following patellofemoral arthroplasty (PFA) versus total knee arthroplasty (TKA). CI, confidence interval; IV, inverse variance weighting.
Complications
Five studies reported complications in the postoperative period (Figure 5). Complications included deep vein thrombosis, manipulation under anaesthetic, surgical site infections, steroid injections, and a facetectomy.11,15,36-38 Overall, there were less complications following a PFA procedure 0.57 (95% CI 0.30 to 1.08).
Fig. 5
Forest plot comparing risk of complications after patellofemoral arthroplasty (PFA) versus total knee arthroplasty (TKA). CI, confidence interval; M-H, Mantel-Haenszel test.
Revision at five years
Five studies reported revision rates after five years (Figure 6). Although the results did not reach statistical significance, in domain 1 there was a trend towards a higher revision rate in TKA while in domain 2 the results were opposite. Data from domain 1 showed a risk ratio (RR) of 3.16 (95% CI 0.87 to 11.40). Data from two studies in the domain 2 analysis showed a RR of 0.26 (95% CI 0.03 to 2.28).
Fig. 6
Forest plot comparing risk of complications after patellofemoral arthroplasty (PFA) versus total knee arthroplasty (TKA). CI, conficence interval; M-H, Mantel-Haenszel test.
Revision at ten years
One study reported revision data comparing 54 PFA and 54 TKA. The revision rate was higher after PFA than after TKA (RR 5.00; 95% CI 0.60 to 41.39). The reasons for revision in the five patients in the PFA group who were reported to have undergone a revision procedure included progression of OA, unexplained pain, and a fracture.
Discussion
This study is aimed at supporting the shared decision-making process between clinicians and patients on outcomes that have been deemed important by the patients themselves following a PPI meeting. However, the quality of the review is dependent on the quality of primary research studies available.47 From this study, in terms of PROMs, the OKS was not able to detect any significant difference. Previous systematic reviews reached similar conclusions to those of our study, that patient reported outcome measures developed to report on the outcome of PFA are not able to detect any differences in outcome between the two procedures.48,49
Quality of life is important as patients with isolated PFJ OA are young and active with normal tibiofemoral compartments. Following a PFA, the tibiofemoral compartment, meniscus, and cruciate ligaments remain preserved, which are important for proprioception, and ultimately patients have better function and biomechanics.12 This fact is supported by a trial which showed patients who had a PFA had a better quality of life in the first two years compared to their TKA counterparts.15,37
PROMs complement objective measurements made by surgeons as they directly measure the patient’s evaluation of their treatment and the ability of the health care process to meet patients expectation.50 In terms of objective measurements, patients with PFAs were found to have a better ROM postoperatively when compared to TKA, with an increase of 4° in one study, a domain which is not detectable using conventional PROMs.15,48 In fact, PFA patients have been found to return to new higher level activities, unlike TKA patients, after which many patients switch to lower impact sports due to loss of normal knee kinematics.11,51-54
There was no difference in revision risk and length of stay across included studies. The revision results differ to a registry based published study consisting of a total of 6,785 PFAs.9 PFAs over five years had a revision risk of 8% in Norway to 18.1% in the Netherlands, three times higher than that of a TKA.9 Despite having higher cumulative revision rates, the study did not account for patient characteristics such as BMI or activity levels, volume of procedures done by the surgeon, or the type of revision procedure the patient underwent.9
The main factor affecting survivorship is failure due to progression of tibiofemoral OA.55 However, one must understand other patient and surgical factors that may affect revision rate. Obesity is associated with a much higher risk of failure and further surgery after PFA similar to other lower limb arthroplasty studies.56 The majority of PFA patients have a high rate of return to their preferred activities implying PFA patients are encouraged to remain active.57 However, activity levels have been linked to higher revision risk in arthroplasty studies.56 Patellofemoral OA affects the younger age group which is associated with higher revision rates, as highlighted by Roussot et al’s12 study. Patients aged less than 65 years had a revision rate of 30.7% compared to 19.9% for patients aged greater than 65 years.12
Surgical factors, such as the surgeon’s expertise or operating in high volume units, may contribute to lower revision rates.58,59 For example, unicompartmental knee arthroplasty (UKA) surgeons report 20% of their arthroplasty practice as UKA achieve lower rates of revision.60,61 To date, there are no studies looking at the surgical volume required to be associated with better outcomes following PFA surgery. Williams et al62 have suggested that PFA surgery should be concentrated in specialist centres.
The first generation trochlear resurfacing implants developed in 1970s, such as Richards (Smith & Nephew, UK) and the Lubinus PFA (Link Orthopaedics, UK), were followed by the introduction of second-generation trochlea cutting PFA devices.63,64 They aimed to reduce the 35% mechanical failure rates associated with the first-generation PFA released in 1979.3,18,65 Therefore, studies combining results from first- and second-generation implants are less likely to give a clear picture, which makes this study unique as it includes only second generation implants.49 The most common complications following PFA are lateral releases, arthroscopic debridement, manipulation under anaesthetic, and soft-tissue realignment procedures.15,36
Strengths and weaknesses
We are not aware of any other study that has used our approach. It is the first to combine both RCTs (domain 1) and cohort studies (domain 2), analyzing outcomes which are deemed to be important following a PPI meeting. Inclusion of level 1 and level 3 evidence has allowed a larger number of cases available for analysis, particularly as, to date, there are very few RCTs published in this area. With a prevalence of 13% of PFJ OA in our young and active population, we have demonstrated lack of good quality data for patients and surgeons to understand the pros and cons for surgery for isolated PFJ OA.3
There are only two other systematic reviews published in this field.48,49 Elbardesy et al48 looked at patient satisfaction, UCLA, and WOMAC PROMs. However, the authors combined patient satisfaction from two articles, which measure satisfaction using different scales. Meanwhile, Bunyoz et al49 looked at complication rates following PFA and TKA; however, this study has a high degree of heterogeneity. The authors combined first- with second-generation prosthesis, in addition to comparing independent case series of solely TKA for PFJ OA with other separate studies of solely PFA for PFJ OA. Our study has included domains deemed important by the patient, we have only included studies using second-generation prosthesis, separated cohort studies from RCTs, and have included those articles that compared TKA and PFA within the same study increasing the degree of homogeneity.
Limitations
PROMs, such as the OKS and KSS, underestimate pain in PFJ OA patients as the major component of the score is pain on walking on level ground.66 In these patients, patients have marked pain on standing up from a chair or climbing stairs.66 Therefore, it is difficult to differentiate between patients with high functional scores.
Using revision as an endpoint in PFA surgery is controversial, as patients with PFJ OA are likely to be younger, with a median age of 58 years, and more active, therefore outlasting their prosthesis.12,32,49 A PFA revision is thought to be a technically less demanding operation due to the bone preserving nature of the procedure and use of an unconstrained prosthesis.8,9 Therefore, a PFA can safely provide adequate symptom relief and burns no bridges for a future TKA.67 Revision of a TKA may result in more bone loss and a more constrained prosthesis.32 However, in terms of comparing the risk of a TKA revision following PFA surgery, as compared to the risk of a TKA undergoing a first time revision, this has been found to be much higher; however, confounding factors, such as age and patient characteristics, have not been accounted for.9
In view of the above limitations, other end points, such as quality of life, ROM, and activity monitoring, would be a better representation of success following PFA surgery rather than revision or knee function specific scores.
This study has included randomized trial data with non-randomized trial data. Similar to the work of Concato et al,68 the results from RCTs and observational studies were remarkably similar. Results from cohort studies should not be abandoned, particularly for a condition that effects up to 23.6% of patients with knee pain, and to date we can not offer adequate evidence which surgical treatment is best.3,4
Future research
There are multiple case series on the optimal surgical treatments for PFJ OA.69 None of the studies describing revision rates have included any description regarding femoral dysplasia morphology classification. This is important as the commonest reasons for revision is progression of tibiofemoral OA.70 Patients with dysplasia have the lowest failure rate.25 Dysplastic femora are less likely to develop tibiofemoral OA progression and have been deemed as the best indication for PFA.21,62,71,72 Meanwhile, patients with tibiofemoral malalignment, and obesity in addition to isolated PFJ OA, may be precursors for generalized tibiofemoral OA progression.73 Further level 4 case series evidence will only create more noise and research waste; any future research should focus on identifying which patients will benefit most from this procedure, assessing confounding factors, such as history of patella dislocations, mental health comorbidities, surgical factors contributing to the success of PFA surgery, and identifying suitable objective postoperative outcomes.
With a prevalence of 18%, a large multicentre RCT, consisting of 528 patients addressing the same questions, could easily cost £2.9 million, as evidenced by TOPKAT.74 Similar to the results from unicompartmental arthroplasties, a well conducted registry-based study can be a helpful addition to the orthopaedic knowledge base and provide a potential solution for young patients.61
In conclusion, this review was aimed at providing patients and surgeons the most up-to-date evidence available on surgical treatment choices for 18% of patients affected with PFJ OA.3 Patients prefer more information when making a final choice for treatment, particularly being able to understand the difference in risks between each option.75 The review gives an insight to the treatment available for those young active PFJ OA patients who may be ‘too young’, are commonly female, more willing to accept disability, and less willing to accept the risk of surgery.76 This review has shown that PFA is associated with a lower risk of complications, but there are no differences in PROMs, revision rate, and length of stay across included studies. PFA surgery should begin to be included as an option in the shared decision-making process between clinicians and patients.
References
1. Kobayashi S , Pappas E , Fransen M , Refshauge K , Simic M . The prevalence of patellofemoral osteoarthritis: a systematic review and meta-analysis . Osteoarthr Cartil . 2016 ; 24 ( 10 ): 1697 – 1707 . Crossref PubMed Google Scholar
2. van der List JP , Chawla H , Villa JC , Pearle AD . Why do patellofemoral arthroplasties fail today? A systematic review . Knee . 2017 ; 24 ( 1 ): 2 – 8 . Crossref PubMed Google Scholar
3. Bohu Y , Klouche S , Sezer HB , Gerometta A , Lefevre N , Herman S . Hermes patellofemoral arthroplasty: annual revision rate and clinical results after two to 20 years of follow-up . Knee . 2019 ; 26 ( 2 ): 484 – 491 . Crossref PubMed Google Scholar
4. Philippe H , Caton J . Design, operative technique and ten-year results of the Hermes patellofemoral arthroplasty . Int Orthop . 2014 ; 38 ( 2 ): 437 – 442 . Crossref Google Scholar
5. Akhbari P , Malak T , Dawson-Bowling S , East D , Miles K , Butler-Manuel PA . The Avon patellofemoral joint replacement: mid-term prospective results from an independent centre . Clin Orthop Surg . 2015 ; 7 ( 2 ): 171 – 176 . Crossref PubMed Google Scholar
6. Stefanik JJ , Niu J , Gross KD , Roemer FW , Guermazi A , Felson DT . Using magnetic resonance imaging to determine the compartmental prevalence of knee joint structural damage . Osteoarthr Cartil . 2013 ; 21 ( 5 ): 695 – 699 . Crossref PubMed Google Scholar
7. Kuwabara A , Cinque M , Ray T , Sherman SL . Treatment options for patellofemoral arthritis . Curr Rev Musculoskelet Med . 2022 ; 15 ( 2 ): 90 – 106 . Crossref PubMed Google Scholar
8. Lonner JH . Patellofemoral arthroplasty: pros, cons, and design considerations . Clin Orthop Relat Res . 2004 ; 428 : 158 – 165 . PubMed Google Scholar
9. Lewis PL , Graves SE , Cuthbert A , Parker D , Myers P . What is the risk of repeat revision when patellofemoral replacement is revised to TKA? An analysis of 482 cases from a large national arthroplasty registry . Clin Orthop Relat Res . 2019 ; 477 ( 6 ): 1402 – 1410 . Crossref PubMed Google Scholar
10. Sabatini L , Giachino M , Risitano S , Atzori F , San Luigi A . Bicompartmental knee arthroplasty . Ann Transl Med . 2016 ; 4 ( 1 ): 5 . Crossref PubMed Google Scholar
11. Dahm DL , Al-Rayashi W , Dajani K , Shah JP , Levy BA , Stuart MJ . Patellofemoral arthroplasty versus total knee arthroplasty in patients with isolated patellofemoral osteoarthritis . Am J Orthop . 2010 ; 39 ( 10 ): 487 – 491 . PubMed Google Scholar
12. Roussot MA , Haddad FS . The evolution and role of patellofemoral joint arthroplasty . Bone Jt Res . 2018 ; 7 ( 12 ): 636 – 638 . Crossref PubMed Google Scholar
13. Dawson J , Fitzpatrick R , Murray D , Carr A . Questionnaire on the perceptions of patients about total knee replacement . J Bone Joint Surg Br . 1998 ; 80-B ( 1 ): 63 – 69 . Crossref PubMed Google Scholar
14. Brittain R , Howard P , Lawrence S , et al. NJR Statistical Analysis, Support and Associated Services . www.njrcentre.org.uk ( date last accessed 5 December 2023 ). Google Scholar
15. Odgaard A , Madsen F , Kristensen PW , Kappel A , Fabrin J . The Mark Coventry Award: patellofemoral arthroplasty results in better range of movement and early patient-reported outcomes than TKA . Clin Orthop Relat Res . 2018 ; 476 ( 1 ): 87 – 100 . Crossref PubMed Google Scholar
16. Coolican M , Budhiparama NC , Lustig S , Maestu R , Price A , Wascher DC . Knee registries . J ISAKOS . 2022 ; S2059-7754(22)00050-5 . Crossref PubMed Google Scholar
17. Garner AJ , Edwards TC , Liddle AD , Jones GG , Cobb JP . The revision partial knee classification system: understanding the causative pathology and magnitude of further surgery following partial knee arthroplasty . Bone Jt Open . 2021 ; 2 ( 8 ): 638 – 645 . Crossref PubMed Google Scholar
18. Dejour D , Saffarini M , Malemo Y , et al. Early outcomes of an anatomic trochlear-cutting patellofemoral arthroplasty: patient selection is key . Knee Surg Sports Traumatol Arthrosc . 2019 ; 27 ( 7 ): 2297 – 2302 . Crossref PubMed Google Scholar
19. van Jonbergen H-PW , Werkman DM , Barnaart LF , van Kampen A . Long-term outcomes of patellofemoral arthroplasty . J Arthroplasty . 2010 ; 25 ( 7 ): 1066 – 1071 . Crossref PubMed Google Scholar
20. Dahm DL , Kalisvaart MM , Stuart MJ , Slettedahl SW . Patellofemoral arthroplasty: outcomes and factors associated with early progression of tibiofemoral arthritis . Knee Surg Sports Traumatol Arthrosc . 2014 ; 22 ( 10 ): 2554 – 2559 . Crossref PubMed Google Scholar
21. Nicol SG , Loveridge JM , Weale AE , Ackroyd CE , Newman JH . Arthritis progression after patellofemoral joint replacement . Knee . 2006 ; 13 ( 4 ): 290 – 295 . Crossref PubMed Google Scholar
22. Stefanik JJ , Guermazi A , Roemer FW , et al. Changes in patellofemoral and tibiofemoral joint cartilage damage and bone marrow lesions over 7 years: the Multicenter Osteoarthritis Study . Osteoarthr Cartil . 2016 ; 24 ( 7 ): 1160 – 1166 . Crossref PubMed Google Scholar
23. Williams DP , Pandit HG , Athanasou NA , Murray DW , Gibbons CLMH . Early revisions of the Femoro-Patella Vialla joint replacement . Bone Joint J . 2013 ; 95-B ( 6 ): 793 – 797 . Crossref PubMed Google Scholar
24. Ajnin S , Buchanan D , Arbuthnot J , Fernandes R . Patellofemoral joint replacement - Mean five year follow-up . Knee . 2018 ; 25 ( 6 ): 1272 – 1277 . Crossref PubMed Google Scholar
25. Argenson JNA , Flecher X , Parratte S , Aubaniac JM . Patellofemoral arthroplasty: an update . Clin Orthop Relat Res . 2005 ; 440 : 50 – 53 . Crossref PubMed Google Scholar
26. Kooijman HJ , Driessen A , van Horn JR . Long-term results of patellofemoral arthroplasty . J Bone Jt Surg Br vol . 2003 ; 85-B ( 6 ): 836 – 840 . Crossref PubMed Google Scholar
27. No authors listed . Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) . http://www.prisma-statement.org/ ( date last accessed 5 December 2023 ). Crossref PubMed Google Scholar
28. Bellamy N , Buchanan WW , Goldsmith CH , Campbell J , Stitt LW . Validation study of WOMAC: a health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee . J Rheumatol . 1988 ; 15 ( 12 ): 1833 – 1840 . PubMed Google Scholar
29. No authors listed . Scoring system for the Oxford Knee Score . https://innovation.ox.ac.uk/wp-content/uploads/2015/07/OKS-and-OKS-APQ-scoring-guide_20150826.doc ( date last accessed 5 December 2023 ). Google Scholar
30. No authors listed . RoB 2: a revised Cochrane risk-of-bias tool for randomized trials . https://methods.cochrane.org/bias/resources/rob-2-revised-cochrane-risk-bias-tool-randomized-trials ( date last accessed 5 December 2023 ). Google Scholar
31. No authors listed . ROBINS-I tool . Cochrane Methods . https://methods.cochrane.org/methods-cochrane/robins-i-tool ( date last accessed 5 December 2023 ). Google Scholar
32. Clement ND , Howard TA , Immelman RJ , et al. Patellofemoral arthroplasty versus total knee arthroplasty for patients with patellofemoral osteoarthritis . Bone Joint J . 2019 ; 101-B ( 1 ): 41 – 46 . Crossref PubMed Google Scholar
33. Foote JAJ , Smith HK , Jonas SC , Greenwood R , Weale AE . Return to work following knee arthroplasty . Knee . 2010 ; 17 ( 1 ): 19 – 22 . Crossref PubMed Google Scholar
34. Fredborg C , Odgaard A , Sørensen J . Patellofemoral arthroplasty is cheaper and more effective in the short term than total knee arthroplasty for isolated patellofemoral osteoarthritis: cost-effectiveness analysis based on a randomized trial . Bone Joint J . 2020 ; 102-B ( 4 ): 449 – 457 . Crossref PubMed Google Scholar
35. Joseph MN , Achten J , Parsons NR , Costa ML , PAT Trial Collaborators . The PAT randomized clinical trial . Bone Joint J . 2020 ; 102-B ( 3 ): 310 – 318 . Crossref PubMed Google Scholar
36. Kamikovski I , Dobransky J , Dervin GF . The clinical outcome of patellofemoral arthroplasty vs total knee arthroplasty in patients younger than 55 years . J Arthroplasty . 2019 ; 34 ( 12 ): 2914 – 2917 . Crossref PubMed Google Scholar
37. Odgaard A , Kappel A , Madsen F , Kristensen PW , Stephensen S , Attarzadeh AP . Patellofemoral arthroplasty results in better time-weighted patient-reported outcomes after 6 years than TKA: a randomized controlled trial . Clin Orthop Relat Res . 2022 ; 480 ( 9 ): 1707 – 1718 . Crossref PubMed Google Scholar
38. Perrone FL , Baron S , Suero EM , et al. Patient-reported outcome measures (PROMs) in patients undergoing patellofemoral arthroplasty and total knee replacement: a comparative study . Technol Health Care . 2018 ; 26 ( 3 ): 507 – 514 . Crossref PubMed Google Scholar
39. Poehling GG , Jenkins CB . Levels of evidence and your therapeutic study: what’s the difference with cohorts, controls, and cases? Arthroscopy . 2004 ; 20 ( 6 ): 563 . Crossref Google Scholar
40. Roos EM , Roos HP , Lohmander LS , Ekdahl C , Beynnon BD . Knee Injury and Osteoarthritis Outcome Score (KOOS)--development of a self-administered outcome measure . J Orthop Sports Phys Ther . 1998 ; 28 ( 2 ): 88 – 96 . Crossref PubMed Google Scholar
41. Naal FD , Impellizzeri FM , Leunig M . Which is the best activity rating scale for patients undergoing total joint arthroplasty? Clin Orthop Relat Res . 2009 ; 467 ( 4 ): 958 – 965 . Crossref PubMed Google Scholar
42. Tegner Y , Lysholm J . Rating systems in the evaluation of knee ligament injuries . Clin Orthop Relat Res . 1985 ; 198 ( 198 ): 43 – 49 . PubMed Google Scholar
43. Insall JN , Dorr LD , Scott RD , Scott WN . Rationale of the Knee Society clinical rating system . Clin Orthop Relat Res . 1989 ; 248 ( 248 ): 13 – 14 . PubMed Google Scholar
44. Ware JE , Sherbourne CD . The MOS 36-ltem Short-Form Health Survey (SF-36) . Medical Care . 1992 ; 30 ( 6 ): 473 – 483 . Crossref Google Scholar
45. Rabin R , de Charro F . EQ-5D: a measure of health status from the EuroQol Group . Ann Med . 2001 ; 33 ( 5 ): 337 – 343 . Crossref PubMed Google Scholar
46. Wilson HA , Middleton R , Abram SGF , et al. Patient relevant outcomes of unicompartmental versus total knee replacement: systematic review and meta-analysis . BMJ . 2019 ; 364 : l352 . Crossref PubMed Google Scholar
47. Charrois TL . Systematic reviews: what do you need to know to get started? Can J Hosp Pharm . 2015 ; 68 ( 2 ): 144 – 148 . Crossref PubMed Google Scholar
48. Elbardesy H , McLeod A , Gul R , Harty J . Midterm results of modern patellofemoral arthroplasty versus total knee arthroplasty for isolated patellofemoral arthritis: systematic review and meta-analysis of comparative studies . Arch Orthop Trauma Surg . 2022 ; 142 ( 5 ): 851 – 859 . Crossref PubMed Google Scholar
49. Bunyoz KI , Lustig S , Troelsen A . Similar postoperative patient-reported outcome in both second generation patellofemoral arthroplasty and total knee arthroplasty for treatment of isolated patellofemoral osteoarthritis: a systematic review . Knee Surg Sports Traumatol Arthrosc . 2019 ; 27 ( 7 ): 2226 – 2237 . Crossref PubMed Google Scholar
50. Anakwe RE , Jenkins PJ , Moran M . Predicting dissatisfaction after total hip arthroplasty: a study of 850 patients . J Arthroplasty . 2011 ; 26 ( 2 ): 209 – 213 . Crossref PubMed Google Scholar
51. Cartier P , Sanouiller JL , Khefacha A . Long-term results with the first patellofemoral prosthesis . Clin Orthop Relat Res . 2005 ; 436 ( 436 ): 47 – 54 . Crossref PubMed Google Scholar
52. Chatterji U , Ashworth MJ , Lewis PL , Dobson PJ . Effect of total knee arthroplasty on recreational and sporting activity . ANZ J Surg . 2005 ; 75 ( 6 ): 405 – 408 . Crossref PubMed Google Scholar
53. Farr J , Arendt E , Dahm D , Daynes J . Patellofemoral arthroplasty in the athlete . Clin Sports Med . 2014 ; 33 ( 3 ): 547 – 552 . Crossref PubMed Google Scholar
54. Strickland SM , Bird ML , Christ AB . Advances in patellofemoral arthroplasty . Curr Rev Musculoskelet Med . 2018 ; 11 ( 2 ): 221 – 230 . Crossref PubMed Google Scholar
55. Marullo M , Bargagliotti M , Vigano’ M , Lacagnina C , Romagnoli S . Patellofemoral arthroplasty: obesity linked to high risk of revision and progression of medial tibiofemoral osteoarthritis . Knee Surg Sports Traumatol Arthrosc . 2022 ; 30 ( 12 ): 4115 – 4122 . Crossref PubMed Google Scholar
56. Ponzio DY , Chiu Y-F , Salvatore A , Lee Y-Y , Lyman S , Windsor RE . An analysis of the influence of physical activity level on total knee arthroplasty expectations, satisfaction, and outcomes: increased revision in active patients at five to ten years . J Bone Joint Surg Am . 2018 ; 100-A ( 18 ): 1539 – 1548 . Crossref PubMed Google Scholar
57. Shubin Stein BE , Brady JM , Grawe B , et al. Return to activities after patellofemoral arthroplasty . Am J Orthop . 2017 ; 46 ( 6 ): E353 – E357 . PubMed Google Scholar
58. Baker PN , Refaie R , Gregg P , Deehan D . Revision following Patello-femoral Arthoplasty . Knee Surg Sports Traumatol Arthrosc . 2012 ; 20 ( 10 ): 2047 – 2053 . Crossref PubMed Google Scholar
59. Metcalfe AJ , Ahearn N , Hassaballa MA , et al. The Avon patellofemoral joint arthroplasty: two- to 18-year results of a large single-centre cohort . Bone Joint J . 2018 ; 100 : 1162 – 1169 . Crossref PubMed Google Scholar
60. Hamilton TW , Pandit HG , Jenkins C , Mellon SJ , Dodd CAF , Murray DW . Evidence-based indications for mobile-bearing unicompartmental knee arthroplasty in a consecutive cohort of thousand knees . J Arthroplasty . 2017 ; 32 ( 6 ): 1779 – 1785 . Crossref PubMed Google Scholar
61. Liddle AD , Pandit H , Judge A , Murray DW . Optimal usage of unicompartmental knee arthroplasty: a study of 41,986 cases from the National Joint Registry for England and Wales . Bone Joint J . 2015 ; 97-B ( 11 ): 1506 – 1511 . Crossref PubMed Google Scholar
62. Williams DP , Pandit HG , Athanasou NA , Murray DW , Gibbons CLMH . Early revisions of the Femoro-Patella Vialla joint replacement . Bone Joint J . 2013 ; 95-B ( 6 ): 793 – 797 . Crossref PubMed Google Scholar
63. Leadbetter WB , Seyler TM , Ragland PS , Mont MA . Indications, contraindications, and pitfalls of patellofemoral arthroplasty . J Bone Joint Surg Am . 2006 ; 88-A Suppl 4 : 122 – 137 . Crossref PubMed Google Scholar
64. Lonner JH . Patellofemoral arthroplasty: the impact of design on outcomes . Orthop Clin North Am . 2008 ; 39 ( 3 ): 347 – 354 . Crossref PubMed Google Scholar
65. Merchant AC . A modular prosthesis for patellofemoral arthroplasty: design and initial results . Clin Orthop Relat Res . 2005 ; 436 : 40 – 46 . Crossref PubMed Google Scholar
66. Laskin RS , van Steijn M . Total knee replacement for patients with patellofemoral arthritis . Clin Orthop Relat Res . 1999 ; 366 ( 367 ): 89 – 95 . PubMed Google Scholar
67. Rammohan R , Gupta S , Lee PYF , Chandratreya A . The midterm results of a cohort study of patellofemoral arthroplasty from a non-designer centre using an asymmetric trochlear prosthesis . Knee . 2019 ; 26 ( 6 ): 1348 – 1353 . Crossref PubMed Google Scholar
68. Concato J , Shah N , Horwitz RI . Randomized, controlled trials, observational studies, and the hierarchy of research designs . N Engl J Med . 2000 ; 342 ( 25 ): 1887 – 1892 . Crossref PubMed Google Scholar
69. Bellemans J . Operative management of patellofemoral arthritis . Curr Opin Orthop . 2000 ; 11 ( 1 ): 19 – 25 . Crossref Google Scholar
70. Liow MHL , Goh GSH , Tay DKJ , Chia SL , Lo NN , Yeo SJ . Obesity and the absence of trochlear dysplasia increase the risk of revision in patellofemoral arthroplasty . Knee . 2016 ; 23 ( 2 ): 331 – 337 . Crossref PubMed Google Scholar
71. Grelsamer RP , Dejour D , Gould J . The pathophysiology of patellofemoral arthritis . Orthop Clin North Am . 2008 ; 39 ( 3 ): 269 – 274 . Crossref PubMed Google Scholar
72. Middleton SWF , Toms AD , Schranz PJ , Mandalia VI . Mid-term survivorship and clinical outcomes of the Avon patellofemoral joint replacement . Knee . 2018 ; 25 ( 2 ): 323 – 328 . Crossref PubMed Google Scholar
73. Farr J , Barrett D . Optimizing patellofemoral arthroplasty . Knee . 2008 ; 15 ( 5 ): 339 – 347 . Crossref PubMed Google Scholar
74. Beard DJ , Davies LJ , Cook JA , et al. The clinical and cost-effectiveness of total versus partial knee replacement in patients with medial compartment osteoarthritis (TOPKAT): 5-year outcomes of a randomised controlled trial . Lancet . 2019 ; 394 ( 10200 ): 746 – 756 . Crossref PubMed Google Scholar
75. Say RE , Thomson R . The importance of patient preferences in treatment decisions--challenges for doctors . BMJ . 2003 ; 327 ( 7414 ): 542 – 545 . Crossref PubMed Google Scholar
76. Novicoff WM , Saleh KJ . Examining sex and gender disparities in total joint arthroplasty . Clin Orthop Relat Res . 2011 ; 469 ( 7 ): 1824 – 1828 . Crossref PubMed Google Scholar
Author contributions
M. Vella-Baldacchino: Conceptualization, Methodology, Investigation, Formal analysis, Writing – original draft.
J. Webb: Conceptualization, Methodology, Investigation, Formal analysis, Validation, Writing – review & editing.
B. Selvarajah: Conceptualization, Methodology, Investigation, Formal analysis, Validation, Writing – review & editing.
S. Chatha: Conceptualization, Methodology, Investigation, Formal analysis, Validation, Writing – review & editing.
A. Davies: Conceptualization, Methodology, Investigation, Formal analysis, Validation, Writing – review & editing.
J. P. Cobb: Conceptualization, Methodology, Investigation, Formal analysis, Validation, Writing – review & editing.
A. D. Liddle: Conceptualization, Methodology, Investigation, Formal analysis, Validation, Writing – review & editing.
Funding statement
The author(s) received no financial or material support for the research, authorship, and/or publication of this article.
ICMJE COI statement
M. Vella-Baldacchino is an Orthopaedic Research UK Early Career Research Fellow (Project no: 551), and discloses grants or contracts from Orthopaedic Research UK. A. Davies declares being a Royal College of Surgeons of England Research Fellow.
Data sharing
The data that support the findings for this study are available to other researchers from the corresponding author upon reasonable request.
Open access funding
The authors report that they received open access funding for this manuscript from Orthopaedic Research UK under Project no: 551.
Trial registration number
Systematic review registration PROSPERO no. CRD42020182597.
Follow M. Vella-Baldacchino @MartiniqueVb
Follow A. D. Liddle @ADLiddle
Supplementary material
Tables showing a summary of the studies included, Cochrane risk-of-bias tool for randomized controlled trials (ROB-2); and Cochrane risk-of-bias in non-randomized studies of interventions (ROBINS-I) tool; and details of the search strategy.
© 2023 Vella-Baldacchino et al. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives (CC BY-NC-ND 4.0) licence, which permits the copying and redistribution of the work only, and provided the original author and source are credited. See https://creativecommons.org/licenses/by-nc-nd/4.0/
