Patient-Reported Outcomes and Risk Factors for Decreased Improvement after Patellofemoral Arthroplasty

Patellofemoral arthroplasty (PFA) is acknowledged as the method for the treatment of isolated patellofemoral osteoarthritis (PFOA). Few previous studies have assessed the patient-reported outcomes (PROs) and risk factors of less improvement of PROs in patients undergoing PFA. A retrospective analysis was performed, including all patients who had undergone PFA. Pre- and postoperative PROs included the Oxford Knee Score (OKS) and Kujala score. Univariate and multivariate statistical analyses were performed to assess influencing factors of less improvement of PROs including the demographic factors (gender, age, body mass index, smoking, opioid usage, and duration of symptoms [DOSs]), surgical factors (concomitant surgery), and imaging factors (trochlear dysplasia [TD], patellar height, the degree of PFOA). A total of 46 PFAs were analyzed with a mean follow-up of 37 ± 7 months. The mean age at surgery was 61.1 ± 7.7 years. Patients showed significant improvement in all PROs (p < 0.001). Patients with TD preoperatively have greater improvement in OKS and Kujala score postoperatively (19.2 ± 5.0 vs. 23.1 ± 3.6, p = 0.038). Longer DOSs (≥1 year) had a greater mean improvement in OKS and Kujala score (p = 0.011 and p = 0.000). According to the measurement of patella height, patients with patella alta (Caton–Deschamps index [CDI] ≥1.3) showed less improvement in both OKS and Kujala score (p = 0.000 and p = 0.002). PFA is a safe and efficient surgery with good PROs. Patella alta with a CDI ≥1.3 and duration of preoperative symptoms ≤ 1 year were risk factors for decreased OKS and Kujala score improvement, while the preoperative presence of TD was significantly predictive factors for increased OKS improvement.

Total Hip Arthroplasty Concomitant with Patellofemoral Arthroplasty and Medial Patellofemoral Ligament Reconstruction for a Patient with Patellar Dislocation Combined with Hip Dysplasia: A Case Report of a Successful Outcome at 5-Year Follow-Up

Background. Posttraumatic patellar dislocation is rare, and consistent surgical strategy therefore has not been defined due to multifactorial factor. In this case study, we treated a case of a patellar dislocation with hip osteoarthritis and increased femoral anteversion by performing a two-staged surgery. In the first stage, total hip arthroplasty was performed, and in the second stage, simultaneous patellofemoral arthroplasty and medial patellofemoral ligament reconstruction using semitendinosus tendon autograft were performed. Case Report. A 56-year-old female patient who previously had right hip osteoarthritis complained of right knee pain after a fall. Radiographic examination showed lateral dislocation of the patella with osteoarthritic (OA) change in the patellofemoral joint and an excessive femoral anteversion with OA change on the right hip joint. Total hip arthroplasty was performed firstly to decrease femoral anteversion. Then, simultaneous patellofemoral arthroplasty and medial patellofemoral ligament reconstruction was performed for residual patellar dislocation and patellofemoral OA without tibiofemoral joint OA. At the time of the 5-year follow-up after surgery, the patient was able to walk with a wheelbarrow without any complications. Conclusion. To the best of our knowledge, this is the first case of a patellar dislocation with an increased femoral anteversion and patellofemoral OA treated by a combination of total hip arthroplasty, patellofemoral arthroplasty, and medial patellofemoral ligament reconstruction. The clinical outcome improved at 5 years after these surgeries. Therefore, these surgical options can be considered to be useful.

Patient-related outcomes of patellofemoral arthroplasty: experience of a single center

Purpose The purpose of this prospective study was to present the experience of a single center on patellofemoral arthroplasty, in terms of patient-related outcomes. Method From January 2005 to January 2016, 42 patients with isolated patellofemoral osteoarthritis were treated. The patients were assessed using the Oxford Knee Score preoperatively, and one, five, and eight year(s) after surgery. The data of the patients were analyzed using linear mixed effects models. A P value of 0.05 was considered statistically significant. Results Among 42 patients who underwent patellofemoral arthroplasty, only 25 patients (31 limbs involved) had records up to 5 years. There was a significant clinical improvement of Oxford Knee Score postoperatively (P < 0.05), lowering the score on average by 10.4 ± 1.5 one year after surgery and 8.9 ± 1.9 five years after surgery. This improvement was independent of the types of implants (P > 0.05), gender (P > 0.05), age (P < 0.05), and body mass index (BMI) (P < 0.05). Conclusion Patellofemoral arthroplasty can significantly improve the knee function, and this improvement is independent of the type of implant, gender, age, and BMI. However, further studies will need to assess the long-term outcomes of PFA.

The short-term effectiveness and safety of second-generation patellofemoral arthroplasty and total knee arthroplasty on isolated patellofemoral osteoarthritis: a systematic review and meta-analysis

Background We aimed to compare second-generation patellofemoral arthroplasty (2G PFA) with total knee arthroplasty (TKA) in treating isolated patellofemoral osteoarthritis (PFOA) by assessing the percentages of revisions, complications, and patient-reported outcome measures (PROMs). Methods Studies that compared the outcomes of 2G PFA and TKA in the treatment of isolated PFOA were searched in electronic databases, including MEDLINE, Embase, and Web of Science. Two researchers independently identified eligible studies, extracted the data, and evaluated the quality of the literature. Pooled risk ratios (RRs) or weighted mean differences with 95% confidence intervals were calculated using either fixed or random effects models. Descriptive analysis was used when data could not be pooled. Results A total of six studies were included in the review. For the revision percentage and complications, there were no significant differences between 2G PFA and TKA (RR = 2.29, 95% CI 0.69–7.58, P = 0.17; RR = 0.56, 95% CI 0.23–1.40, P = 0.22, respectively). Second, the results demonstrated that the differences in the Oxford Knee Score (OKS) and the University of California, Los Angeles (UCLA) activity score between 2G PFA and TKA were not significant (WMD −4.68, 95% CI −16.32 to 6.97, p = 0.43; WMD 0.16, 95% CI −1.21 to 1.53, P = 0.82). The Knee Injury and Osteoarthritis Outcome Score (KOOS), the American Knee Society Score (AKSS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were presented in a narrative form due to methodological heterogeneity. Conclusion For isolated PFOA, 2G PFA demonstrated similar results to TKA with respect to the percentages of revisions, complications, and PROMs.

Good Operative Effects of Patellofemoral Arthroplasty Combined With the Tibial Tubercle Transfer for Isolated Patellofemoral Arthritis Patients With an Increased Tibial Tuberosity-trochlear Groove Distance

Purpose: The objective of present study was to investigate the operative effect of patellofemoral arthroplasty combined with the tibial tubercle transfer for isolated patellofemoral arthritis patients with an increased tibial tuberosity-trochlear groove distance (>20mm).Methods: A prospective study was performed between November 2012 and December 2017. Finally, thirty-six cases, with a mean age of 61.1 ± 7.3 years, were admitted to our study. A total of 17 patients underwent patellofemoral arthroplasty combined with tibial tubercle transfer, and 19 patients underwent patellofemoral arthroplasty only. All eligible patients had CT scans preoperatively and at 12 months follow-up, to assess the stability of the patellofemoral joint on axial slices. In addition, the demographic and clinical features of all the patients were asked. Knee balance was assessed with the single leg stance test and timed get up and go, and functionality was evaluated with stair climbing test and the Western Ontario and McMaster Universities Osteoarthritis Index score. (P>0.05)Results: Preoperatively, the data regarding the knee balance and functionality were not significantly different between the two Groups (P>0.05). Many measurements showed significant differences between the two groups at the last follow-up. Significant differences were seen in well-known measurements such as the SLST (Group I, 28.9 s (SD 7.5); Group II, 20.3 s (SD 5.9); p < 0.001), TGUG (Group I, 13.4 s (SD 3.2); Group II, 16.8 s (SD 3.1); p < 0.001), and SCT (Group I, 18.6 s (SD 6.8); Group II, 24.5 s (SD 8.7); p < 0.001). Additionally, the median WOMAC score was improved from 62.7 (SD 11.2) preoperatively to 25.7 (SD 8.2) one year postoperatively in Group I and from 64.1 (SD 10.7) to 36.2 (SD 9.7) in Group II, which were also significantly different between the groups.Conclusion: For such special IPA patients with an increased TT-TG (>20mm), the combined operation of PFA combined with TTT can better restore the involutional relationship of patellofemoral joint and further improve the balance and function of knee joint.

Patellofemoral arthroplasty versus total knee arthroplasty for isolated patellofemoral osteoarthritis: a systematic review and meta-analysis

Background Isolated patellofemoral osteoarthritis (PF-OA) is a common subtype of knee osteoarthritis, leading to a huge economic burden on health care systems. Although previous studies have shown that patellofemoral arthroplasty (PFA) and total knee arthroplasty (TKA) have good clinical effects, it remains largely unclear which treatment is more effective for patients with isolated PF-OA. We aimed to compare postoperative function, complications, revision rates, level of physical activity, and satisfaction rate between the two surgical techniques. Methods Our study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Search of literature was conducted in MEDLINE, EMBASE, Cochrane Library, and Web of Science until November 2020. The included studies were those that provided direct comparison of postoperative outcomes between PFA and TKA. Data were extracted from eligible studies and combined to calculate the pooled odds ratio (OR) and 95% confidence interval (CI). Sensitivity analysis and subgroup analysis were conducted to evaluate heterogeneity between the two groups. Results A total of 7 eligible studies (3 recent randomized controlled trials and 4 nonrandomized controlled trials) were included in this meta-analysis. The pooled results showed that both the PFA group and the TKA group had improved postoperative indicators, suggesting that the two operation modes could improve the knee function and quality of life of patients. Throughout the first 2 years postoperatively, higher activity level, and better functional recovery were observed for PFA compared with TKA in this study; moreover, the differences between the two operation modes were statistically significant (p < 0.05). We found no significant difference in complications, revision rates, and satisfaction rate between the two procedures. Conclusion Although there was no observed difference in the complications, revision rates, and satisfaction rate between PFA and TKA, PFA was superior to TKA in terms of knee function and physical activity in the first 2 years postoperatively. Therefore, PFA is a safe, effective, and less invasive treatment for patients with isolated PF-OA. Our findings are consistent with the systematic review of current evidence that PFA may be more suitable for younger patients with high activity needs. Patient selection is, therefore, thought to be of paramount importance. Individualized surgical plan should be designed according to the patient’s age, BMI, KOA site, and activity level and combined with the doctor’s personal experience.