Changes in clinical symptoms and functional disability in patients with coexisting patellofemoral and tibiofemoral osteoarthritis: a 1-year prospective cohort study

Patellar malalignment correlates with increased pain and increased synovial stress hormone levels-A cross-sectional study

PURPOSE

Risk factors for the development of pain in the context of knee osteoarthritis (KOA) remain unclear. Radiological findings often do not correlate with clinical findings, so other pathomechanisms in the development and perception of pain must play a role. The purpose of this study is to investigate the correlation of increased sympathetic nervous system (SNS) activity (measured by subjective and objective chronic stress parameters) with KOA severity, patellofemoral malalignment, and pain.

METHODS

47 patients with KOA were assessed. Radiological measurements of tibiofemoral and patellofemoral parameters (Kellgren-Lawrence-score, patellar tilt (PT), Caton-Deschamps-Index and Hepp´s classification) were performed and correlated with knee-specific questionnaires (WOMAC®, KSS©) and chronic stress questionnaires (PSQ-20). Additionally, parameters associated with chronic stress were quantified in synovial fluid and serum samples from patients.

RESULTS

PT correlated significantly with Caton-Deschamps-Index (r = 0.394,p = 0.006) and with medial patellofemoral joint space (r = 0.516,p<0.001). In addition, asymmetric trochlear groove (Hepp's classification > II) was associated with significantly higher PT values (p = 0.014). A negative correlation between PT and KSS©-symptoms subgroup was found (r = -0.340,p = 0.024). Patients with PT<5° had significantly higher scores in the Knee Society Score©-symptoms subgroup (p = 0.038). A positive and significant correlation between synovial aldosterone levels and PT was observed (r = 0.548,p = 0.042).

CONCLUSION

The results of this study indicate that patellar malalignment might correlate with increased pain. The previous specification of standard PT values must be reconsidered as even low PT values seem to play a role in the occurrence of patellofemoral osteoarthritis symptoms. Lower PT values might lead to aggravated symptoms in patients with KOA due to a narrow medial patellofemoral joint space. In addition, PT might induce the release of synovial stress biomarkers and thus contribute to the progression of KOA.

Decision-making factors and their thresholds for total knee arthroplasty in lateral tibiofemoral osteoarthritis patients: a retrospective cohort study

BACKGROUND

There has been no study examining lateral tibiofemoral (TF) osteoarthritis (OA) and objective decision-making factors affecting when patients decide to have total knee arthroplasty (TKA). The purpose of this study was to assess which factors and their thresholds cause patients with lateral TF OA to decide on TKA.

METHODS

We conducted a retrospective cohort study and identified patients who had initially been diagnosed with isolated lateral TF OA from October 2004 to February 2021. We finally included 56 patients; patients who had chosen conservative treatment followed by in-depth interviews for the deliberation stage (n = 32), and the other patients who decided to undergo TKA for the decision-making stage (n = 24). Demographic, clinical, and radiographic characteristics were considered candidate predictive factors. Radiographic variables included the Ahlbäck grade, hip-knee-ankle (HKA) angle, joint line convergence angle (JLCA), and TF subluxation. Univariate and multivariate logistic regression analyses were performed.

RESULTS

Clinically, the pain visual analog scale (VAS) score was significantly higher and the knee flexion angle was lower at the decision-making stage. Radiographic measurements showed that the Ahlbäck grade, HKA angle, JLCA, and TF subluxation measured at the center, in addition to the tibiotalar angle, differed statistically between the two stages. According to univariate analyses, two clinical characteristics and six radiographic variables on the ipsilateral side of the leg, and one radiographic variable on the contralateral side of the leg were included as factors influencing the patients' decision to undergo TKA. After making adjustments based on multivariate analysis, the ipsilateral knee pain VAS (OR = 1.61; 95% CI = 1.14-2.28, p = 0.007) and medial TF subluxation measured at the center (OR = 1.14, 95% CI = 1.01-1.32, p = 0.072) were found to be significant factors for choosing TKA. The area under the curve (AUC) for pain VAS was 0.757 and the cutoff value was 4.5. The AUC for TF subluxation measured at the center was 0.697 and the cutoff value was -4.10% of medial TF subluxation.

CONCLUSION

Higher ipsilateral knee pain VAS and more severe medial TF subluxation measured at the center were independent factors affecting patient decisions to undergo TKA with lateral TF OA. Understanding the determining factors that may affect patient decision-making when considering TKA may be an essential aspect of evaluating the prognosis of patients with lateral TF OA.

LEVEL OF EVIDENCE

III.

Does arthroscopic patellar denervation with high tibial osteotomy improve anterior knee pain?

PURPOSE

Patellofemoral (PF) joint osteoarthritis (OA) is a major cause of anterior knee pain. Combined PF and medial tibiofemoral (TF) OA is common in older adults. We evaluated the effect of arthroscopic patellar denervation (PD) in patients with combined TF and PFOA after malalignment correction.

METHODS

Forty-five patients [females/males, 27/18; age, 30-59 years (45.5 ± 8.50); mean body mass index, 25.15 ± 3.04 kg/m²] were treated in our department from March 2017 to March 2019. The patients were randomised into 2 groups: group A included 22 patients who underwent open-wedge high tibial osteotomy (OWHTO) and arthroscopic PD and group B included 23 patients who underwent OWHTO without denervation. The effect of denervation was statistically and clinically evaluated using the Knee injury and Osteoarthritis Outcome Score (KOOS) and Kujala (anterior knee pain score) score.

RESULTS

After 24 months, 40 patients were available for the final follow-up. The final values of KOOS and the Kujala score were significantly different between the groups (p < 0.001). For group A, the average KOOS improved from 42.73 to 72.38 (p < 0.001) and the Kujala score improved from 42 to 74.1 (p < 0.001), whereas in group B, the average KOOS improved from 39.22 to 56.84 (p < 0.001) and the Kujala score improved from 39.7 to 56.4 (p < 0.001).

CONCLUSION

Adding arthroscopic PD to OWHTO relieves anterior knee pain in patients with combined TF and PFOA and improves knee joint function and quality of life.

LEVEL OF EVIDENCE

Level I prospective randomised control clinical trial.

Exploratory Study of 6-Month Pain Trajectories in Individuals With Predominant Patellofemoral Osteoarthritis: A Cohort Study

BACKGROUND

Knowledge of patellofemoral osteoarthritis (OA) pain trajectories is vital to helping clinicians and patients make shared disease-specific decisions regarding treatment options and coping strategies.

OBJECTIVES

To describe the pain trajectories of people living with patellofemoral OA who present to a chronic care management program, and to explore baseline characteristics associated with different trajectories.

METHODS

In this prospective longitudinal cohort study, 88 participants who presented to a chronic care management program reported their worst pain over the previous week at baseline and at 6, 12, 18, and 26 weeks using a 10-cm visual analog scale. Trajectories (classes) were identified using latent class growth analysis. Demographics, pain, physical performance, strength, quality of life, mental health, and lower limb/foot structural measures obtained at baseline were assessed for association with trajectory class membership.

RESULTS

Individuals in class 1 (28%) exhibited high, persistent pain from baseline (7.8 ± 1.7 cm), which continued over time (P = .52). Class 2 (57%) displayed moderate baseline pain (4.8 ± 1.8 cm), which also remained persistent (P = .97). Individuals in class 3 (15%) showed low, improving pain (baseline pain, 2.6 ± 1.2 cm) over time (P = .017). At baseline, poor Knee injury and Osteoarthritis Outcome Score (KOOS) scores, local and proximal sensitivity to pressure, and lower knee extensor strength were associated with increased odds of following the high-pain trajectory (range [95% confidence interval], 1.03 [1.00, 1.07] to 16.24 [2.53, 104.34]).

CONCLUSION

Distinct pain trajectories appear to exist in people with patellofemoral OA presenting to a chronic care management program. Baseline variables may be useful for identifying individuals at risk of poorer prognosis. Larger studies are needed to confirm the efficacy of this finding.

LEVEL OF EVIDENCE

Prognosis, level 2b. J Orthop Sports Phys Ther 2019;49(1):5-16. Epub 12 Sep 2018. doi:10.2519/jospt.2019.8354.

Local associations between knee cartilage T1ρ and T2 relaxation times and patellofemoral joint stress during walking: A voxel-based relaxometry analysis

BACKGROUND

This study aimed to utilize voxel-based relaxometry (VBR) to examine local correlations between patellofemoral joint (PFJ) stress during gait and PFJ cartilage relaxation times.

METHODS

Eighty-three subjects with and without PFJ osteoarthritis (OA) underwent knee magnetic resonance (MR) images using fast spin-echo, T1ρ and T2 relaxation time sequences. Patellar and trochlear cartilage relaxation times were computed for each voxel. Peak PFJ stress was computed during the stance phase from three-dimensional gait analysis. Statistical Parametric Mapping was used to perform VBR analyses. Pearson partial correlations were used to evaluate the associations between peak PFJ stress and cartilage relaxation times while controlling for age, sex, and body mass index.

RESULTS

A higher percentage of the trochlear cartilage (15.9-29.1%) showed significant positive correlations between PFJ stress and T1ρ and T2 than the patellar cartilage (7.4-13.6%). Average correlation coefficient (R) of the voxels showing significant positive correlations ranged from 0.27 to 0.29. Subcompartment analysis revealed a higher percentage of lateral compartment cartilage (trochlea: 30.2-34.7%, patella: 8.1-14.8%) showed significant correlations between peak PFJ stress and T1ρ and T2 than the medial compartment cartilage (trochlea: 7.1-27.2%, patella: 5.5-5.9%). Subgroup analysis showed that larger percentages of PFJ cartilage demonstrated significant positive correlations with PFJ stress in subjects with PFJ OA than those without PFJ OA.

CONCLUSIONS

The findings of this study suggest that peak PFJ stress has a greater influence on the biochemical composition of the trochlear than the patellar cartilage, and the lateral than the medial PFJ compartment.

Association of varus thrust with prevalent patellofemoral osteoarthritis: A cross-sectional study

This cross-sectional study investigated (i) the association of varus thrust during gait with the presence of patellofemoral osteoarthritis (PFOA) in patients with medial knee osteoarthritis (OA) and (ii) patellar alignment in the knees with varus thrust. Participants from orthopedic clinics (n=171; mean age, 73.4 years; 71.9% female) diagnosed with radiographic medial knee OA (Kellgren/Lawrence [K/L] grade ≥1) were included in this study, and underwent gait observation for varus thrust assessment using 2D video analysis. A radiographic skyline view was used to assess the presence of medial PFOA using the grading system from the Osteoarthritis Research Society International Atlas. The tibiofemoral joint K/L grade, patellar alignment (i.e., lateral shift and tilting angle), and knee pain intensity were also evaluated as covariates. Thirty-two (18.7%) of 171 patients exhibited varus thrust and they presented significantly higher knee pain (46.0±3.04mm vs. 32.4±2.73mm; P=0.024), a lower patellar tilting angle (P=0.024), and a higher prevalence of PFOA compared with those without varus thrust. A logistic regression analysis with adjustment of covariates showed that varus thrust was significantly associated with higher odds of the presence of mixed and medial PFOA, and trended to significantly associate with any PFOA, including lateral PFOA. This indicates that varus thrust was associated with PFOA in a compartment-nonspecific manner in patients with medial knee OA. Varus thrust may represent a clinical disease feature of more advanced and multicompartmental disease.