The comparison of anterior knee pain in severe and non severe arthritis of the lateral facet of the patella following a mobile bearing unicompartmental knee arthroplasty

The impact of patellofemoral joint diseases on functional outcomes and prosthesis survival in patients undergoing unicompartmental knee arthroplasty: a systematic review and meta-analysis

BACKGROUND

Patellofemoral joint (PFJ) diseases are chronic degenerative conditions that contribute to knee joint symptoms. Unicompartmental knee arthroplasty (UKA) is widely regarded as an effective treatment for knee osteoarthritis (KOA); however, its specific indications remain a subject of debate.

HYPOTHESIS

Patients with PFJ disease are expected to experience outcomes post-UKA comparable to those of patients without PFJ disease.

METHODS

We conducted this meta-analysis following the guidelines outlined by the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). A comprehensive search of PubMed, Embase, and Web of Science databases was conducted for studies examining the association between PFJ disease and UKA, including publications up to September 2024. Extracted data encompassed author, publication year, country, disease type, prosthesis type, sample size, mean patient age, gender distribution, follow-up duration, PFJ disease prevalence at surgery, diagnostic methods, and whether PFJ disease was considered a contraindication for UKA. To maintain objectivity, only studies in which PFJ diseases were visually identifiable were included in the meta-analysis. Statistical analyses were performed using Stata 15.0 and Review Manager 5.4.1. A random-effects meta-analysis was conducted to evaluate the Oxford Knee Score (OKS), Knee Society Score (KSS), flexion range of motion (ROM), Forgotten Joint Score (FJS), Tegner activity score, and prosthesis survival rate, with outcomes stratified by PFJ disease type (PFJ degeneration or patella cartilage injury). Mean differences, confidence intervals, and P values were calculated for comparisons between the PFJ disease and non-PFJ disease groups. The Methodological Index for Non-Randomized Studies (MINORS) criteria and the Newcastle-Ottawa Scale (NOS) were applied to evaluate the risk of bias. To address heterogeneity, sensitivity analyses were performed, and publication bias was assessed using funnel plots and Egger's test.

RESULTS

A total of 14,866 knees from 48 relevant studies were included in this systematic review. Methodological quality was assessed using the MINORS criteria, with case series scoring 11.0/16 and cohort studies scoring 18.2/24. PFJ degeneration emerged as the most studied condition, followed by patella cartilage injury. Clinical outcomes assessments indicated that medial PFJ degeneration, anterior knee pain, patella cartilage damage, and patella baja did not significantly impact UKA outcomes or prosthesis survival. However, severe lateral PFJ degeneration, lateral patellar subluxation, lateral trochlear osteophytes, and patellar bone marrow edema did influence results. Fifteen high-quality studies were included in the meta-analysis, involving 6080 patients-1338 in the PFJ disease group and 4,742 in the non-PFJ disease group. With an average NOS score of 7.2, the studies were generally of high quality. Meta-analysis results showed no significant differences between groups in final follow-up OKS, FJS, Tegner activity score, or prosthesis survival rate. However, the PFJ disease group had lower KSS and reduced flexion ROM compared to the non-PFJ disease group. Subgroup analysis further revealed that the PFJ degeneration group scored lower than the patella cartilage injury group on OKS, KSS, and flexion ROM following UKA.

CONCLUSION

In summary, PFJ disease was found to have limited impact on UKA outcomes; however, caution is recommended for cases involving severe lateral PFJ degeneration due to potential restrictions in postoperative knee function, particularly affecting flexion ROM in UKA patients.

The efficacy of patellar denervation on prognosis and kneeling capacity after unicompartmental knee arthroplasty: a randomized clinical trial

OBJECTIVE

The aim of this study was to investigate the effect of patellar denervation (PD) on pain, function and ability to kneel after unicompartmental knee arthroplasty (UKA).

METHODS

Patients with medial knee osteoarthritis who underwent UKA were prospectively selected. Patients were randomly divided into PD and non-PD groups based on whether patellar denervation was performed. Clinical assessment was performed using the Hospital for Special Surgery (HSS) knee score, Kujiala score, visual analogue scale (VAS) and forgotten joint score (FJS-12), as well as postoperative complications were recorded. The patients' postoperative self-perception and actual ability to perform different kneeling positions were assessed in the two groups.

RESULTS

UKA patients treated with PD achieved better Kujiala scores and FJS-12 scores, reduced anterior knee pain and improved kneeling ability postoperatively, validating the effectiveness of PD in UKA. Perception and actual performance of kneeling remained mismatched in PD patients, but performance during different kneeling activities was generally better than in non-PD patients.

TRIAL REGISTRATION

Clinical Trial Registration: ChiCTR1900025669.

CONCLUSION

Patellar denervation can safely and effectively improve patellofemoral joint function, pain and kneeling ability in the early postoperative period after UKA.

A decreased tibial tuberosity-trochlear groove distance is associated with lateral patellofemoral joint degeneration after implantation of medial fixed-bearing unicompartmental knee arthroplasty - a minimum five year follow-up

PURPOSE

The influence of lateral patellofemoral osteoarthritis (PFOA) in medial unicompartmental knee arthroplasty (UKA) is controversial. Our aim was to identify radiographic factors that may lead to progressive PFOA after implantation of a fixed-bearing medial UKA and their impact on patient-reported outcomes (PROMs).

METHODS

A retrospective consecutive cohort of patients undergoing medial UKA with a minimum follow-up of 60 months between September 2011 and January 2017 was identified. All UKAs had a fixed-bearing design with cemented femoral and tibial components. PROMs included documentation of the Oxford Knee Score (OKS). The following radiographic parameters were evaluated on conventional radiographs and computer tomography (CT) scans: patella tilt angle, patella congruence angle, Caton-Deschamps index, medial and lateral patellofemoral degeneration (Kellgren-Lawrence Classification (KL)), mechanical anteroposterior axis, femoral torsion, tibial tuberosity to trochlear groove distance (TTTG), anteroposterior translation of the femoral component. A hierarchical multiple regression analysis and partial Pearson correlation analysis (SPSS) were used to evaluate for predictors of progression of lateral PFOA.

RESULTS

Forty-nine knees allowed PFOA assessment and had an average follow-up of 62 months (range 60-108). Twenty-three patients did not exhibit any progression of lateral PFOA. Twenty-two progressed with 1 stage, whereas four had progressed 2 stages according to the KL classification. TTTG negatively correlated with progressive lateral PFOA (r =  - 0.436, p = 0.01). Progression of lateral PFOA did not correlate with OKS at last follow-up (p = 0.613).

CONCLUSION

A decreased TTGT correlated with radiographic progression of lateral PFOA after medial fixed-bearing cemented UKA. PFOA however did not influence PROMs at a minimum of five years postoperatively.

The Role of Severe Lateral Facet Patellar Osteoarthritis in Patient Selection for Success of a Medial Unicompartmental Knee Arthroplasty: Mean Follow-Up of 10 Years

BACKGROUND

Lateral facet patellar osteoarthritis (LFPOA) has been reported as a contraindication for medial unicompartmental (UKA). The purpose of this paper was to determine if severe LFPOA was related to lower survivorship and patient-reported outcomes following medial UKA.

METHODS

A total of 170 medial UKAs were performed. Severe LFPOA was defined as Outerbridge grade 3 to 4 damage on the lateral facet cartilage surfaces of the patella as noted intraoperatively. There were 122 of 170 patients (72%) who had noLFPOA and 48 of 170 patients (28%) who had had severe LFPOA. A routine patelloplasty was performed in all patients. Patients completed the Veterans RAND 12-Item Health Survey (VR-12) Mental Component Score (MCS) and Physical Component Score (PCS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Knee Society Score.

RESULTS

There were 4 patients in the noLFPOA group who required total knee arthroplasty and 2 in the LFPOA group. There was no significant difference in mean survival time: noLFPOA = 17.2 years [95% confidence interval (CI): 17 to 18] and LFPOA = 18.0 years [95% CI: 17 to 19] (P = .94). At mean follow-up of 10 years, there were no significant differences in knee flexion or extension. Patello-femoral crepitus without pain was noted in 7 patients who had LFPOA and 21 patients who had noLFPOA. There were no significant differences in VR-12 MCS, PCS, KOOS subscales, or Knee Society Score between groups. Patient acceptable symptom state (PASS) was achieved in 80% (90 of 112) for KOOS ADL in the noLFPOA group and 82% (36 of 44) in the LFPOA group (P = .68). PASS was achieved in 82% (92 of 112) for KOOS Sport in the noLFPOA group and 82% (36/44) in the LFPOA group (P = .87).

CONCLUSION

At a mean of 10 years, patients who had LFPOA had equivalent survivorship and functional outcomes to patients who did not have LFPOA. These long-term results suggest that asymptomatic grade 3 or 4 LFPOA is not a contraindication to medial UKA.

Influence of patellofemoral joint degeneration on clinical outcomes after medial unicompartmental knee arthroplasty

BACKGROUND

Patellofemoral joint (PFJ) degeneration has traditionally been regarded as a contraindication to unicompartmental knee arthroplasty (UKA). More recently, some researchers have proposed that PFJ degeneration can be ignored in medial UKA, and others have proposed that this change should be reviewed in PFJ degenerative facets and severity. This study aimed to systematically evaluate the effect of PFJ degeneration on patient-reported outcome measures (PROMs) and revision rates after medial UKA.

METHODS

Electronic databases (PubMed, Embase, Web of Science, etc.) were searched for studies assessing the influence of PFJ degeneration on medial UKA. A random-effects meta-analysis was conducted for the Oxford knee score (OKS), Knee society score (KSS), and revision rates and stratified by PFJ degenerative facets (medial/lateral/trochlear/unspecified), severe PFJ degeneration (bone exposed), and bearing type (mobile/fixed). Heterogeneity was assessed by the Cochran Q test statistic and chi-squared tests with the I-squared statistic.

RESULTS

A total of 34 articles with 7007 knees (2267 with PFJ degeneration) were included (5762 mobile-bearing and 1145 fixed-bearing) and 100 unspecified. Slight to moderate degenerative changes in the medial and trochlear facets did not decrease the OKS and KSS, and only lateral facets significantly decreased the OKS (mean difference [MD] = -2.18, P  < 0.01) and KSS (MD = -2.61, P  < 0.01). The severity degree of PFJ degeneration had no additional adverse effect on the OKS, KSS, or revision rates. For mobile-bearing UKA, only lateral PFJ degeneration significantly decreased the OKS (MD = -2.21, P < 0.01) and KSS (MD = -2.44, P < 0.01). For fixed-bearing UKA, no correlation was found between PROMs/revision rates and PFJ degeneration.

CONCLUSION

For medial mobile-bearing UKA, slight to moderate degenerative changes in the PFJ, except lateral facet, did not compromise PROMs or revision rates. For medial fixed-bearing UKA, although it might not be conclusive enough, PROMs or revision rates were not adversely affected by PFJ degeneration (regardless of the facet).

A structured evaluation of the symptomatic medial Oxford unicompartmental knee arthroplasty (UKA)

Unicompartmental knee arthroplasty (UKA) has several advantages over total knee arthroplasty; however, in many reports, the risk of revision remains higher after UKA.Many reasons for failure of UKA exist.Successful treatment starts with accurate assessment of the symptomatic UKA as a specific mode of failure requires a specific solution.A structured and comprehensive evaluation aids assessment of the symptomatic UKA.This review provides an overview of the causes for a symptomatic medial UKA, its risk factors, diagnostic modalities that can be used, and briefly discusses treatment options. Cite this article: EFORT Open Rev 2021;6:850-860. DOI: 10.1302/2058-5241.6.200105.

Comparison of Long-Term Survival Analysis Between Open-Wedge High Tibial Osteotomy and Unicompartmental Knee Arthroplasty

BACKGROUND

To compare unicompartmental knee arthroplasty (UKA) and open-wedge high tibial osteotomy (OWHTO) in a long-term follow-up propensity score matching analysis.

METHODS

Patients who underwent UKA or OWHTO for unilateral medial unicompartmental osteoarthritis (OA) between 2004 and 2010 were included. The ROM, HSS score, KS score, WOMAC score, forgotten joint score, OA progression in patellofemoral and lateral compartments, and survivorship were compared within ten years of follow-up between 67 UKA and 67 OWHTO patients after propensity score matching for age, gender, body mass index, range of motion, and osteoarthritis (OA) grade.

RESULTS

At the last follow-up, there were no significant differences between the two groups in clinical outcomes, but the WOMAC score showed better results after UKA (13.1 in UKA vs 18.9 in OWHTO, P = .011). The OA progression also showed no significant difference between the two groups. After a 10-year follow-up, the survival rate was higher in UKA patients (96.2%) than in OWHTO patients (87.7%), with no statistical difference (P = .06).

CONCLUSION

UKA showed better clinical outcomes and OA progressions than OWHTO. The survival rate presented a superiority of 8.5% for the UKA group in the 10-year follow-up, without significant difference.

The outcomes of mobile bearing unicompartmental knee arthroplasty and total knee arthroplasty on anteromedial osteoarthritis of the knee in the same patient

INTRODUCTION

Compared to total knee arthroplasty (TKA), mobile-bearing unicompartmental knee arthroplasty (UKA) is associated with better outcomes, such as an earlier recovery, less postoperative pain, lower morbidity and mortality, and a greater "feel" of a normal knee. However, no study has reported the clinical outcomes in patients with the same stage of osteoarthritis of the knee. The purpose of this study was to determine the clinical outcomes, including the Joint Forgotten Score (JFS), Oxford Knee Score (OKS), Knee Society Score (KSS), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Kujala score after UKA on one knee and TKA on the opposite knee in the same patient.

MATERIALS AND METHODS

We retrospectively reviewed 32 patients with anteromedial OA who underwent mobile-bearing UKA in one knee and TKA in the other knee from 2009 to 2017. The JFS, OKS, KSS, KOOS, and Kujala scores were recorded and compared between the groups. Patients' preferences between UKA and TKA and satisfaction were also recorded.

RESULTS

The JFS and KOOS in the UKA group were significantly (p = 0.01, 0.01) higher than those in the TKA group: 97.01 ± 3.26 (89.58-100) vs. 94.92 ± 3.34 (87.80-100) and 91.16 ± 2.67 (85.25-96) vs. 89.24 ± 2.67 (84.50-94.71), respectively. The OKS, KSS, and Kujala scores were not different between the two groups (p = 0.82, 0.95, and 0.31, respectively) and neither was patient preference (p = 0.41) or satisfaction (p = 0.42). The mean follow-up was 48.36 months (range 24.00-96.00 months), during which there were no postoperative complications.

CONCLUSION

UKA was associated with a better JFS and KOOS but was otherwise comparable to TKA and may be preferable.

Short-term improvement of patellofemoral pain in medial unicompartmental knee arthroplasty with patellar denervation: a prospective comparative study

INTRODUCTION

Medial osteoarthritis (OA) knees with symptomatic patellofemoral (PF) arthritis were not recommended for UKA in the past. However, UKA has shown good clinical results in patients with medial OA knee with symptomatic PF arthritis. On the contrary, this procedure is not recommended for patients with severe PF OA. Patella denervation (PD) by circumferential electrocautery can reduce the severity and incidence of anterior knee pain in TKA. However, to the best of our knowledge, there are no studies reporting anterior knee pain and complications of medial UKA with PD in severe PF OA.

OBJECTIVE

We have conducted a prospective comparative study to assess the short-term results of anterior knee pain and complications after medial UKA with PD or without PD in medial compartment arthritis and severe PF arthritis patients.

MATERIAL AND METHODS

This prospective comparative study was conducted from January 2018-September 2019 at Pranungkaew Hospital, Nonthaburi, Thailand. A total of 66 patients with medial compartment and severe patellofemoral arthritis were allocated to UKA with or without patella denervation. The primary outcomes were Kujala anterior knee pain scale and complications measured at 6 months after the surgery.

RESULTS

Sixty-six patients (37 patients undergoing UKA with PD and 27 patients undergoing UKA without PD) of medial compartment and severe lateral facet patellofemoral arthritis (62 female, 4 male; mean age 60.16 (5.03) years; 17 PF grade III, 49 PF grade IV) were included in this study. The mean preoperative Kujala scores were 54.96 (range 30-80) (SD 2.59) in the no-PD group (group I) and 47.77 (range 27-75) (1.62) in the PD group (group II), respectively (p value = 0.009). All baseline characteristics were also comparable between treatment groups except the preoperative Kujala score. The mean final value of Kujala score was 70.22 (range 50-96) (2.40) in the no-PD group (group I) and 80.10 (range 60-95) (SD 1.50) in the PD group (group II), respectively (p value < 0.001). The mean difference of Kujala score was statistically significantly higher by 9.88 (4.48, 15.28) points in the PD group when compared to the no-PD group. There were no complications in both groups after surgery.

CONCLUSIONS

Patellar denervation seems to provide short-term benefits improving the Kujala score in patients with PF OA undergoing UKA.

LEVEL OF EVIDENCE

III. Trial Registration ClinicalTrials.gov: NCT03676179.

[Research progress about influence of patellofemoral osteoarthritis on effectiveness of unicompartmental knee arthroplasty]

Objective

To summarize the current research progress about influence of patellofemoral osteoarthritis on clinical outcome of unicompartmental knee arthroplasty (UKA).

Methods

The recent related literature was extensively reviewed and summarized, including pros and cons to regard the patellofemoral osteoarthritis as the contraindication.

Results

Previous studies regarded patellofemoral osteoarthritis as the contraindication of UKA. Most of current researches show that the damage to the articular cartilage of the patellofemoral joint to the extent of full-thickness cartilage loss has no influence on outcome of UKA. There is no correlation between preoperative anterior knee pain or medial patellofemoral joint degeneration and the clinical outcome. However, lateral subluxation of the patella has an adverse impact on postoperative curative effect. Degeneration of the lateral patellofemoral joint may be a risk factor of the outcome.

Conclusion

Patellofemoral osteoarthritis should not be the absolute contraindication of UKA. The effect of degeneration of the lateral patellofemoral joint is not clear at present, and still needs further studies in the future.

Clinical outcomes of patients with residual medial osteophytes following mobile bearing unicompartmental knee arthroplasty

Introduction

The surgical technique used in unicompartmental knee arthroplasty (UKA) is crucial for achieving good short and long term clinical outcomes. The medial mobile bearing UKA has shown excellent clinical outcomes and survivorship. But release of the medial collateral ligament during entering joint is cause of mobile bearing dislocation in short term outcomes and lateral compartment osteoarthritis may occur in the mid to long term outcomes. Removing all osteophytes at the time of UKA is sometime impossible due to their large size and extend to the inferior part of medial tibial plateau and removing them completely my result in release of the MCL. But no data exist on clinical outcomes in such patients.

Methods

We conducted a prospective study from 2010 to 2015 of patients undergoing mobile bearing UKA and classified them in to two groups: those with (Gp1) and without (Gp2) residual osteophytes. Osteophyte size was measured using Hernborg’s technique. The primary outcomes were pain score, functional score, and knee scores and the presence of reported medial knee pain.

Results

176 patients who underwent 199 mobile bearing UKAs were recruited: Gp1 = 42 patients (46 knees) and Gp2 = 134 patients (153 knees). Residual osteophyte sizes ranged from 2.13–9.42 mm (mean 4.12). The mean Gp1 Gp2 pain score (49.04, 48.92, p = 0.84), functional score (83.75, 84.04, p = 0.83) and knee score (89.86, 98.7, p = 0.0.78) scores were almost identical and no one complained of medial joint pain. Followed up ranged from 2 − 7 years (mean 4.23). No patients were lost to follow up.

Conclusion

The patients with residual osteophytes of length less than 9 mm had good and similar clinical outcomes as patients without residual osteophytes following mobile bearing UKA.

Level of evidence

Level II-2, evidence obtained from well-designed cohort studies or case-control studies, preferably from more than one center or research group.

Outcomes of mobile bearing unicompartmental knee arthroplasty in medial osteoarthritis knee with and without preoperative genu recurvatum

AIM

To compare clinical outcomes of patients with and without preoperative genu recurvatum (GR) following mobile bearing unicompartmental knee arthroplasty (UKA).

METHODS

We prospectively followed 176 patients for at least 24 mo who had been treated by unilateral, minimally invasive, Oxford UKA. Patients with medial osteoarthritis (OA) knee and preoperative GR (Group I) accounted for 18% (n = 32) and patients without preoperative GR (Group II) accounted for the remaining 82% (n = 144). Knee score, pain scores, and functional scores were assessed for each patient and compared between the two groups. The incidence of postoperative GR and the postoperative hyperextension angles also were recorded and analyzed.

RESULTS

The pain score, knee score and functional score were not significantly different between the two groups. Similarly, the incidence of postoperative GR and the measured hyperextension angles were not significantly different between the two groups. The incidence of postoperative GR was 1/32 (3.12%) in Group I and 1/144 (0.69%) in Group II (P = 0.34). The mean postoperative hyperextension angles were 2.40° ± 2.19° (range: 1°-7°) for Group I and 1.57° ± 3.51° (range: 1°-6°) for Group II (P = 0.65).

CONCLUSION

Medial OA of the knee and concomitant GR is not a contraindication for the mobile bearing UKA.

Does location of patellofemoral chondral lesion influence outcome after Oxford medial compartmental knee arthroplasty?

Aims

Medial unicompartmental knee arthroplasty (UKA) is associated with successful outcomes in carefully selected patient cohorts. We hypothesised that severity and location of patellofemoral cartilage lesions significantly influences functional outcome after Oxford medial compartmental knee arthroplasty.

Patients and Methods

We reviewed 100 consecutive UKAs at minimum eight-year follow-up (96 to 132). A single surgeon performed all procedures. Patients were selected based on clinical and plain radiographic assessment. All patients had end-stage medial compartment osteoarthritis (OA) with sparing of the lateral compartment and intact anterior cruciate ligaments. None of the patients had end-stage patellofemoral OA, but patients with anterior knee pain or partial thickness chondral loss were not excluded. There were 57 male and 43 female patients. The mean age at surgery was 69 years (41 to 82). At surgery the joint was carefully inspected for patellofemoral chondral loss and this was documented based on severity of cartilage loss (0 to 4 Outerbridge grading) and topographic location (medial, lateral, central, and superior or inferior). Functional scores collected included Oxford Knee Score (OKS), patient satisfaction scale and University College Hospital (UCH) knee score. Intraclass correlation was used to compare chondral damage to outcomes.

Results

All patients documented significant improvement in pain and improved functional scores at mid-term follow-up. There were four revisions (mean 2.9 years, 2 to 4; standard deviation (sd) 0.9) in this cohort, three for tibial loosening and one for femoral loosening. There was one infection that was treated with debridement and insert exchange. The mean OKS improved from 23.2 (sd 7.1) to 39.1 (sd 6.9); p < 0.001. The cohort with central and lateral grade 3 patellofemoral OA documented lower mean satisfaction with pain (90, sd 11.8) and function (87.5, sd 10.3) on the patient satisfaction scale. On the UCH scale, patients reported significantly decreased mean overall scores (7.3, sd 1.2 vs 9, sd 2.3) as well as stair climb task (3.5, sd 0.3 vs 5, sd 0.1) when cartilage lesions were located centrally or laterally on the PFJ. Patients with medial chondral PFJ lesions behave similar to patients with no chondral lesions.

Conclusion

Topographical location and severity of cartilage damage of the patella can significantly influence function after successful Oxford medial UKA. Surgeons should factor this in when making their operative decision, and undertake to counsel patients appropriately.

Cite this article: Bone Joint J 2016;98-B(10 Suppl B):11–15.