Patellofemoral Joint Cartilage Research Articles

MRI analysis of and factors related to knee injuries in amateur marathon runners.

Marathons are the most challenging form of running, and amateur athletes may be more prone to injury due to a lack of professional knowledge and instruction in running. To analyze the MRI manifestations of and factors related to knee injuries in amateur marathon runners. Data were collected from a hospital database of 105 qualified amateur marathon athletes (65 males,40 females), between May 2018 and December 2021. 1.5T MR: sagittal fs-PDWI, sagittal T1WI and sagittal 3D-DESS sequence. The MRI manifestations of knee joint injury were analyzed and evaluated by two radiologists. The inter-observer agreement on MRI readings was analyzed using the kappa coefficient, and binary logistic regression analysis was employed to identify factors associated with knee injuries. The overall prevalence of knee cartilage lesions, meniscus lesions and bone marrow edema among amateur marathon runners was 45.7%, 72.4%, and 49.5% respectively. Our analysis revealed that older age (OR = 1.135, P<0.001), higher BMI (OR = 1.236, P = 0.044), and slower pace (OR = 2.305, P = 0.017) were associated with increased risk of articular cartilage disease. Furthermore, older age (OR = 1.425, P<0.001) was identified as a risk factor for meniscal lesions, while older age (OR = 1.088, P = 0.002) was bone marrow edema. Notably, no significant correlation was observed between knee joint injuries of amateur marathon athletes and gender or the monthly running distance (P>0.05). The occurrence of knee injuries among amateur marathon athletes was highly prevalent, with the patellofemoral joint cartilage and posterior horn of medial meniscus being frequently affected areas. Moreover, age, BMI, running years and pace were significant risk factors of knee joint injury.

Patellofemoral joint cartilage lesions frequently develop shortly after anterior cruciate ligament reconstruction using hamstring tendon autograft: A systematic review.

This study aimed to investigate the development of patellofemoral joint (PFJ) cartilage lesions following anterior cruciate ligament reconstruction (ACLR) using hamstring tendon (HT) autograft through a systematic review. A comprehensive search was conducted in PubMed, Embase, Cochrane Library and Google Scholar databases to find articles published from database inception until 15 November 2023. The search terms were [('Anterior Cruciate Ligament' [mesh] OR 'anterior cruciate ligament' OR 'ACL') AND 'reconstruction' AND 'cartilage' AND ('second look arthroscopy' OR 'second-look arthroscopy' OR 'MRI' OR 'magnetic resonance imaging')]. Inclusion criteria were studies that reported on the occurrence of PFJ cartilage lesions following ACLR using HT autograft, as determined by second-look arthroscopy or follow-up magnetic resonance imaging (MRI). Fifteen studies (1084 patients) met the inclusion criteria, with follow-up periods ranging from 1 to 5 years. In the results of second-look arthroscopy, cartilage grade deterioration was observed, ranging from MDs of 0.1 to 2.0 in the patella and from 0 to 1.0 in the trochlea. Follow-up MRI results reported the incidence of PFJ cartilage degeneration with rates ranging from 20% to 44%. Patient-reported outcome measures often showed no significant association with PFJ cartilage lesions. The studies included in this review reported various risk factors for cartilage lesion development. Cartilage lesions in the PFJ, detected using second-look arthroscopy or follow-up MRI, frequently develop shortly after ACLR using HT autograft. At this stage, patients might not show specific symptoms; however, those with risk factors require careful observation and evaluation by clinicians during follow-up. Level IV.

Femoral trochlear groove cartilage damage after open-wedge high tibial osteotomy is associated with the change in patellar height relative to the femoral condyle

BackgroundMedial open-wedge high tibial osteotomy (OWHTO) is performed for isolated medial compartment osteoarthritis or osteonecrosis of the knee and correction of varus deformity of the full lower extremity. OWHTO may induce sagittal parameter changes, including these in the tibial posterior slope (TPS), patellar height (PH), and patellofemoral joint problems. This study aimed to identify radiographic parameters associated with patellofemoral cartilage damage after OWHTO. HypothesisThe patellofemoral joint cartilage worsens after OWHTO and is adversely affected by PH changes. Patients and methodsTwenty patients (25 knees) who underwent primary OWHTO and subsequent implant removal surgery, including second-look arthroscopy for evaluation of the patellofemoral cartilage condition were enrolled. The patients were received 12 to 35 months of postoperative follow-up, and categorized into two groups according to whether patellofemoral cartilage damage worsened. TPS and PH parameters, including the Insall–Salvati, Blackburne–Peel, Caton–Deschamps, and modified Blumensaat (MBI) indices, were measured on lateral knee radiographs. The hip-knee-ankle and medial proximal tibial angles were measured using an anteroposterior radiograph of the full lower extremity. The extent of change from preoperative to postoperative (Δ) was calculated for all indices. ResultsEleven knees (44%) had worsening cartilage conditions in the femoral trochlear groove, with>1-degree of deterioration in the International Cartilage Repair Society grade. The radiographic measure for predicting patellofemoral cartilage deterioration was ΔMBI (95% confidence interval [CI]: 3.53×10–14–0.812, p=0.047). PF cartilage damage tended to progress in ΔMBI<–0.145. The postoperative TPS and HKAA in patients with deterioration in patellofemoral cartilage damage was greater than that in patients without deterioration in patellofemoral cartilage damage (p=0.037 and 0.038, respectively). DiscussionThe patellofemoral cartilage damage tends to progress after OWHTO. ΔMBI is a factor for predicting worsening patellofemoral cartilage condition. However, attention should be paid to the excessive posterior slope as high TPS and valgus alignment as valgus HKAA because intraoperative control of MBI is impossible. Level of evidenceIV, retrospective study.

MRI analysis of and factors related to knee injuries in amateur marathon runners.

Marathons are the most challenging form of running, and amateur athletes may be more prone to injury due to a lack of professional knowledge and instruction in running. To analyze the MRI manifestations of and factors related to knee injuries in amateur marathon runners. Data were collected from a hospital database of 105 qualified amateur marathon athletes (65 males,40 females), between May 2018 and December 2021. 1.5T MR: sagittal fs-PDWI, sagittal T1WI and sagittal 3D-DESS sequence. The MRI manifestations of knee joint injury were analyzed and evaluated by two radiologists. The inter-observer agreement on MRI readings was analyzed using the kappa coefficient, and binary logistic regression analysis was employed to identify factors associated with knee injuries. The overall prevalence of knee cartilage lesions, meniscus lesions and bone marrow edema among amateur marathon runners was 45.7%, 72.4%, and 49.5% respectively. Our analysis revealed that older age (OR = 1.135, P<0.001), higher BMI (OR = 1.236, P = 0.044), and slower pace (OR = 2.305, P = 0.017) were associated with increased risk of articular cartilage disease. Furthermore, older age (OR = 1.425, P<0.001) was identified as a risk factor for meniscal lesions, while older age (OR = 1.088, P = 0.002) was bone marrow edema. Notably, no significant correlation was observed between knee joint injuries of amateur marathon athletes and gender or the monthly running distance (P>0.05). The occurrence of knee injuries among amateur marathon athletes was highly prevalent, with the patellofemoral joint cartilage and posterior horn of medial meniscus being frequently affected areas. Moreover, age, BMI, running years and pace were significant risk factors of knee joint injury.

Poster 248: Lateral extra-articular tenodesis augmentation of anterior cruciate ligament reconstruction does not impact cartilage health in the patellofemoral joint based on post-operative two year qualitative and quantitative MRI analysis

Objectives: Lateral extra-articular tenodesis (LET) augmentation of anterior cruciate ligament reconstruction (ACLR) has been shown in multiple clinical and biomechanics studies to be an effective procedure to control rotational laxity, reducing failure rates. However, it is uncertain whether augmentation with an iliotibial band based LET may cause increased contact pressure in the patellofemoral joint (PFJ), resulting in cartilage damage. The purpose of the current study was to assess PFJ cartilage status in patients that underwent ACLR with or without LET augmentation using magnetic resonance imaging (MRI). It was hypothesized that 1) the addition of LET at the time of ACLR would have no effect on cartilage health on post-operative two-year MRI; 2) higher cartilage relaxation values would be associated with worse patient reported and functional outcomes at two years post-operatively. Methods: A subset of patients from the STABILITY 1 randomized controlled trial were included. All patients underwent primary ACLR with a hamstring autograft. The patients were randomized either to receive LET augmentation (modified Lemaire technique) or not. Cartilage status in the PFJ between ACLR alone group and ACLR+LET group were compared by quantitative MRI (qMRI) analysis of T2 and T1 rho sequences (figure 1), and qualitative assessment by ACL osteoarthritis score (ACLOAS) on post-operative two year MRI for surgical and contralateral non-surgical knees. Objective functional outcomes (range of motion (ROM), hop test and isokinetic strength) and patient reported outcome measures including Knee injury Osteoarthritis and Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) score were attained. Descriptive statistics were calculated for each group using means and standard deviations (SD) for continuous variables and proportions for categorical variables. ANCOVA was used to determine the adjusted mean difference in T1rho and T2 relaxation times between groups for each compartment in the patella and trochlea. Spearman’s rho was used to assess the correlation between relaxation times within each compartment and patient-reported and functional outcomes at two-years postoperative. Statistical significance was set at P = 0.05. Results: Ninety-two patients (43 patients in ACLR group, mean age (±SD) 18.9±3.2 years, 60.5% female, and 49 patients in ACLR+LET group, 18.7±3.2 years, 63.3% females) were included. No significant differences were seen in patient background, meniscal treatment and cartilage status at the time of surgery (table 1). No significant differences were seen in the mean values (milliseconds) for qMRI for adjusted T1 rho relaxation times in the medial patella (MP) (47.8 vs 47.3), central patella (CP) (45.5 vs 44.1), and lateral patella (LP) (48.2 vs 47.3), and medial trochlea (MT) (54.7 vs 56.4), central trochlea (CT) (53.3 vs 53.1), and lateral trochlea (LT) (54.9 vs 53.9), and adjusted T2 relaxation times in MP (42.2 vs 43.2), CP (42.5 vs 42.7), LP (43.5 vs 43.0), MT (50.9 vs 50.9), CT (51.1 vs 52.0), LT (52.1 vs 52.6) between ACLR and ACLR+LET groups. Similarly, no difference in ACLOAS scores (overall score 10 vs 11, p = 0.99) were observed. An increase in medial patellar T2 relaxation times were associated with decreasing IKDC score (p = 0.046), KOOS symptoms subscale (p = 0.01), and total KOOS score (p = 0.01). Increasing limb symmetry on the hop test was associated with increasing T1ρ (p = 0.04) and T2 (p = 0.01) relaxation in the lateral trochlea Conclusions: No difference was found in patellofemoral cartilage health between knees undergoing primary ACLR with hamstring tendon autograft with or without LET at two years post-operative. Statistically significant correlations were found between qMRI relaxation times and functional outcome scores and PROMs, however the correlations were weak and the clinical significance of these changes are undetermined. [Table: see text]

Poster 300: A Novel Magnetic Resonance Imaging (MRI) Scoring System to Evaluate Patellofemoral Osteoarthritis

Objectives: Knee osteoarthritis (OA) is a common degenerative or post-traumatic condition, and may affect one or more compartments, including the medial and lateral tibiofemoral or patellofemoral articulations. Isolated patellofemoral osteoarthritis (PFOA) has been reported in 24% of women and 11% of men aged &gt; 55 years presenting for evaluation of knee pain. PFOA is a result of abnormal mechanical loading across the patellofemoral joint, often related to prior instability, trauma, malalignment or post- surgical changes. Treatment of PFOA typically includes a trial of conservative management, including physical therapy, injections and activity modification. Operative treatment involves joint preservation (i.e., cartilage restoration procedures, tibial tubercle osteotomy, or lateral lengthening) and joint replacement (patellofemoral arthroplasty) procedures. In contrast to the tibiofemoral compartments, the current literature lacks a reliable magnetic resonance imaging (MRI) scoring system to quantitatively evaluate patellofemoral cartilage degeneration. The present study aims to describe, apply and assess the inter-observer reliability of a novel MRI scoring system for assessment of the patellofemoral cartilage. Methods: We conducted a query of an institutional database to identify all patients who underwent patellofemoral arthroplasty by the senior surgeon (S.M.S.) between January 2012 and December 2021. Patients with poor quality or lacking preoperative knee MRI were excluded. MRI scans were performed on 1.5 or 3.0-Tesla magnets utilizing dedicated extremity coils and standardized clinical imaging protocols consistent with International Cartilage Regeneration and Joint Preservation Society (ICRS) guidelines for the assessment of articular cartilage. Preoperative MRI scans were reviewed and patellofemoral cartilage was scored by a fellowship-trained musculoskeletal radiologist and a fellowship- trained orthopedic knee surgeon using our novel MRI scoring system. The novel semi-quantitative MRI patellofemoral scoring system includes assessment of patellar and trochlear cartilage, bony architecture, patellofemoral alignment, and synovitis (Table 1). For statistical analysis, inter-observer agreement was assessed using Cohen-Kappa coefficient for categorical variables, and intraclass correlation coefficient (ICC) for the total score. The measurement agreement for reach variable and total score was interpreted according to the Landis and Koch criteria: 0 - 0.2, slight; 0.21 - 0.4, fair; 0.41 - 0.6, moderate; 0.61 - 0.80, substantial; 0.81 - 1.0, almost perfect. Results: A total of 72 patients were included in the final analysis. The mean (± standard deviation) age and body mass index (BMI) of all patients was 53.30±7.72 years and 27.3±5.37 kg/m, respectively. Patellar bone edema and patellar cysts demonstrated moderate inter-observer agreement. All cartilage features, trochlear bone edema and cysts, osteophytes, subchondral remodeling, patellar height, and synovitis demonstrated substantial inter-observer agreement. Patellofemoral alignment and total score demonstrated almost perfect inter-observer agreement (Table 2 and Figure 1). Conclusions: The novel MRI scoring system for PFOA proposed by the authors is an attempt to develop a comprehensive method to assess patellofemoral joint cartilage degeneration, including evaluation of patellar and trochlear cartilage changes, bony architecture, patellofemoral alignment, and synovitis. Importantly, all features of the scoring system demonstrated at least moderate inter-observer agreement, with the majority of variables and total score demonstrating substantial to near perfect agreement. Future studies should aim to validate this scoring system in patients with and without patellofemoral arthritis and attempt to correlate scores with clinical outcomes. [Table: see text][Table: see text]

Persistent underloading of patellofemoral joint following hamstring autograft ACL reconstruction is associated with cartilage health

To determine the longitudinal changes of patellofemoral joint (PFJ) contact pressure following anterior cruciate ligament reconstruction (ACLR). To identify the associations between PFJ contact pressure and cartilage health. Forty-nine subjects with hamstring autograft ACLR (27 males; age 28.8 [standard deviation, 8.3] years) and 19 controls (12 males; 30.7 [4.6] years) participated. A sagittal plane musculoskeletal model was used to estimate PFJ contact pressure. A combined T1ρ/T2 magnetic resonance sequence was obtained. Assessments were performed preoperatively, at 6 months, 1, 2, and 3 years postoperatively in ACLR subjects and once for controls. Repeated Analysis of Variance (ANOVA) was used to compare peak PFJ contact pressure between ACLR and contralateral knees, and t-tests to compare with control knees. Statistical parametric mapping was used to evaluate the associations between PFJ contact pressure and cartilage relaxation concurrently and longitudinally. No changes in peak PFJ contact pressure were found within ACLR knees over 3 years (preoperative to 3 years, 0.36 [CI, -0.08, 0.81] MPa), but decreased over time in the contralateral knees (0.75 [0.32, 1.18] MPa). When compared to the controls, ACLR knees exhibited lower PFJ contact pressure at all time points (at baseline, -0.64 [-1.25, -0.03] MPa). Within ACLR knees, lower PFJ contact pressure at 6 months was associated with elevated T2 times (r=-0.47 to -0.49, p=0.021-0.025). Underloading of the PFJ following ACLR persists for up to 3 years and has concurrent and future consequences in cartilage health. The non-surgical knees exhibited normal contact pressure initially but decreased over time achieving limb symmetry.

Patellofemoral joint loading and early osteoarthritis after ACL reconstruction.

Patellofemoral joint (PFJ) osteoarthritis is common following anterior cruciate ligament reconstruction (ACLR) and may be linked with altered joint loading. However, little is known about the cross-sectional and longitudinal relationship between PFJ loading and osteoarthritis post-ACLR. This study tested if altered PFJ loading is associated with prevalent and worsening early PFJ osteoarthritis post-ACLR. Forty-six participants (mean ± 1 SD age 26 ± 5 years) approximately 1-year post-ACLR underwent magnetic resonance imaging (MRI) and biomechanical assessment of their reconstructed knee. Trunk and lower-limb kinematics plus ground reaction forces were recorded during the landing phase of a standardized forward hop. These data were input into a musculoskeletal model to calculate the PFJ contact force. Follow-up MRI was completed on 32 participants at 5-years post-ACLR. Generalized linear models (Poisson regression) assessed the relationship between PFJ loading and prevalent early PFJ osteoarthritis (i.e., presence of a PFJ cartilage lesion at 1-year post-ACLR) and worsening PFJ osteoarthritis (i.e., incident/progressive PFJ cartilage lesion between 1- and5-years post-ACLR). A lower peak PFJ contact force was associated with prevalent early PFJ osteoarthritis at 1-year post-ACLR (n = 14 [30.4%]; prevalence ratio: 1.37; 95% confidence interval [CI]: 1.02-1.85) and a higher risk of worsening PFJ osteoarthritis between 1- and 5-years post-ACLR (n = 9 [28.1%]; risk ratio: 1.55, 95% CI: 1.13-2.11). Young adults post-ACLR who exhibited lower PFJ loading during hopping were more likely to have early PFJ osteoarthritis at 1-year and worsening PFJ osteoarthritis between 1- and 5-years. Clinical interventions aimed at mitigating osteoarthritis progression may be beneficial for those with signs of lower PFJ loading post-ACLR.

Baseline cartilage T1ρ and T2 predicted patellofemoral joint cartilage lesion progression and patient-reported outcomes after ACL reconstruction.

This study aims to determine if baseline T1ρ and T2 will predict cartilage morphological lesion progression in the patellofemoral joint (PFJ) and patient-reported outcomes at 2-year after anterior cruciate ligament (ACL) reconstruction (ACLR). Thirty-nine ACL-injured patients were studied at baseline and two-year after ACLR. 3 T MR T1ρ and T2 images and Knee Injury and Osteoarthritis Outcome Score (KOOS) were acquired at both time points. Voxel-based relaxometry (VBR) technique was used to detect local cartilage abnormalities. Patients were divided into progression and non-progression groups based on changes of the whole-organ magnetic resonance imaging scoring (WORMS) grading of cartilage in PFJ from baseline to 2-year, and into lower (more pain) and higher (less pain) KOOS pain groups based on 2-year KOOS pain scores, separately. Voxel-based analyses of covariance were used to compare T1ρ and T2 values at baseline between the defined groups. Using VBR analysis, the progression group at 2-year showed higher T1ρ and T2 compared with the non-progression group at baseline, with the medial femoral condyle showing the largest areas with significant differences. At two-year, 56% of patients were able to recover with respect to KOOS pain. The lower KOOS pain group at 2-year showed significantly elevated T1ρ and T2 in the patella at baseline compared with the higher KOOS pain group. In conclusion, baseline T1ρ and T2 mapping, combined with VBR analysis, may help identify ACLR patients at high risk of developing progressive PFJ cartilage lesions and worse clinical symptoms 2-year after surgery.

Quadriceps strength is negatively associated with knee joint structural abnormalities—data from osteoarthritis initiative

ObjectiveThe aim of this study was to explore the longitudinal associations between baseline quadriceps strength and knee joint structural abnormalities in knee osteoarthritis (KOA).MethodsThis study is a longitudinally observational study based on Osteoarthritis Initiative (OAI) cohort, including men and women aged 45–79. Quadriceps strength was measured by isometric knee extension testing at baseline. Knee joint structural abnormalities, including cartilage damage, bone marrow lesions (BMLs), effusion-synovitis and Hoffa-synovitis, were evaluated by Magnetic Resonance Imaging Osteoarthritis Knee Score (MOAKS) at baseline and 1-year follow-up. Generalized estimating equations were employed to examine the associations between quadriceps strength and knee structural abnormalities. All analyses were stratified by sex.ResultsOne thousand three hundred thirty-eight participants (523 men and 815 women) with a mean age of 61.8 years and a mean BMI of 29.4 kg/m2 were included in this study. For men, no significantly longitudinal association of quadriceps strength with structural abnormalities was detected. In contrast, quadriceps strength was significantly and negatively associated with changes in cartilage damage and BMLs in lateral patellofemoral joint (PFJ) (cartilage damage: OR: 0.91, 95% CI 0.84 to 0.99, P = 0.023; BMLs: OR: 0.85, 95% CI 0.74 to 0.96, P = 0.011) and effusion-synovitis (OR = 0.88, 95% CI 0.78 to 0.99, P = 0.045) among females longitudinally. Higher quadriceps strength was significantly associated with less progression of lateral PFJ cartilage damage, BMLs and effusion-synovitis in females.ConclusionsHigher quadriceps strength was associated with changes in cartilage damage and BMLs within the lateral PFJ and effusion-synovitis among females, suggesting the potential protective role of quadriceps strength on joint structures in women.

Poster 242: Deep Learning for Identifying Patellofemoral Measurements Associated with Cartilage Lesions on MRI

Poster 242: Deep Learning for Identifying Patellofemoral Measurements Associated with Cartilage Lesions on MRI

Factors Influencing the Progression of Patellofemoral Articular Cartilage Damage After Anterior Cruciate Ligament Reconstruction.

Background:Although anterior cruciate ligament reconstruction (ACLR) can restore the stability and function of the knee joint, patellofemoral joint cartilage damage still progresses. Currently, the clinically important factors that lead to the progression of patellofemoral articular cartilage damage are not fully understood.Purpose:To investigate the factors that affect the progression of patellofemoral articular cartilage damage after ACLR.Study Design:Cohort study; Level of evidence, 2.Methods:Among 160 patients who underwent ACLR between January 2015 and December 2019, the authors evaluated 129 patients for at least 1 year after surgery. Within 1 week before ACLR and at the last follow-up, patients underwent subjective functional assessment and magnetic resonance imaging evaluations of articular cartilage damage (modified Outerbridge assessment). At the last follow-up, the side-to-side difference on KT-2000 arthrometer and bilateral quadriceps muscle strength were measured. Univariate and multivariate logistic regression analyses were performed.Results:The mean follow-up was 24.69 ± 10.74 months. Progression of patellar cartilage damage from preoperatively to final follow-up was seen in 45 patients (P < .001). Logistic regression analysis revealed that the follow-up period (P = .047; odds radio (OR) = 0.953) (improvement of patellar cartilage damage with longer follow-up), partial lateral meniscal resection (P = .004; OR = 6.929), partial medial meniscal resection (P = .004; OR = 6.032), and quadriceps muscle strength <80% of the contralateral side (P = .001; OR = 4.745) were risk factors for the progression of patellar cartilage damage.Conclusion:Cartilage damage at the patellofemoral joint, especially the patellar cartilage, still progresses after ACLR. At a mean follow-up of 24.69 months after ACLR, partial meniscal resection and quadriceps femoris muscle strength were found to be the main risk factors for the progression of patellofemoral articular cartilage damage after ACLR.

Hip-Knee Joint Coordination Patterns are Associated With Patellofemoral Joint Cartilage Composition in Patients With Anterior Cruciate Ligament Reconstruction.

Joint coordination variability during walking that is associated with patellofemoral joint cartilage degeneration after anterior cruciate ligament reconstruction are not well understood. The purpose of this study was to assess between-limb differences in joint coordination variability and to determine the relationship of coordination variability with postoperative patellofemoral joint cartilage composition. Thirty-five patients underwent bilateral gait analysis and a magnetic resonance exam of the reconstructed knee joint at 6months post anterior cruciate ligament reconstruction. Vector coding was used to assess coordination variability during the early (1%-33%), mid (34%-66%), and late (67%-100%) stance phase. The T1ρ/T2 mapping was used to evaluate the glycosaminoglycan-collagen matrix of the patellar and femoral trochlear cartilage. Compared with the uninjured limb, the reconstructed limb exhibited higher hip sagittal/knee sagittal plane coordination variability during midstance as well as higher knee sagittal/ankle sagittal plane coordination variability during both mid and late stance. The hip sagittal/knee sagittal plane coordination variability during midstance predicted 14.6% of the variance in patellar cartilage T1ρ values within the reconstructed limb. In addition, sex of participants was able to predict 32.4% and 13.7% of the variance in femoral trochlea T1ρ and T2 values, respectively. The study results demonstrate that a multijoint mechanism may be associated with early patellofemoral joint cartilage degeneration at 6months after anterior cruciate ligament reconstruction.

Etiology of Cartilage Lesions Does Not Affect Clinical Outcomes of Patellofemoral Autologous Chondrocyte Implantation.

To determine the relationship between cartilage lesion etiology and clinical outcomes after second-generation autologous chondrocyte implantation (ACI) in the patellofemoral joint (PFJ) with a minimum of 2 years' follow-up. A retrospective review of all patients that underwent ACI in the PFJ by a single surgeon was performed. Seventy-two patients with a mean follow-up of 4.2 ± 2.0 years were enrolled in this study and were stratified into 3 groups based on the etiology of PFJ cartilage lesions: patellar dislocation (group 1; n = 23); nontraumatic lesions, including chondromalacia, osteochondritis dissecans, and degenerative defects (group 2; n = 28); and other posttraumatic lesions besides patellar dislocations (group 3; n = 21). Patient's mean age was 29.6 ± 8.7 years. Patients in group 1 were significantly younger (25.4 ± 7.9 years) than group 2 (31.7 ± 9.6 years; P = 0.025) and group 3 (31.5 ± 6.6 years; P = 0.05). Body mass index averaged 26.2 ± 4.3 kg/m2, with a significant difference between group 1 (24.4 ± 3.2 kg/m2) and group 3 (28.7 ± 4.5 kg/m2; P = 0.005). A clinical comparison was established between groups based on patient-reported outcome measures (PROMs) and failure rates. Neither pre- nor postoperative PROMs differed between groups (P > 0.05). No difference was seen in survivorship between groups (95.7% vs. 82.2% vs. 90.5%, P > 0.05). Cartilage lesion etiology did not influence clinical outcome in this retrospective study after second generation ACI in the PFJ. Level III, retrospective comparative study.

PATELLOFEMORAL JOINT CARTILAGE RESTORATION WITH PARTICULATED JUVENILE ALLOGRAFT IN PATIENTS UNDER 21 YEARS OLD: POSTOPERATIVE MRI ANALYSIS AND RETURN TO SPORT RATES

Background:Patellofemoral joint cartilage defects are difficult to treat due to their unique thickness and topography. Numerous cartilage restoration techniques are available to surgeons treating articular cartilage defects. However, patellofemoral joint restoration historically produces worse outcomes than tibiofemoral joint restoration. One cell-based option is particulated juvenile allograft cartilage (PJAC), though literature regarding the efficacy of this treatment is sparse, especially in patients under the age of 21 years.Hypothesis/ Purpose:The aim of this study is to investigate postoperative outcomes of PJAC for patellofemoral chondral defects using MRI and return to sport rates in this active, high-demand patient population.Methods:Patients at an urban tertiary care musculoskeletal institution who underwent PJAC for patellofemoral joint cartilage restoration were identified through records review. Patients 21 years old or younger with minimum clinical follow-up of 1 year and postoperative MRI at a minimum of 6 months after surgery were included. Cartilage restoration was assessed by MRI using the International Cartilage Repair Society’s standardized system. Sport activity was collected from medical records.Results:Thirty-six knees in 34 patients with a mean age of 16.1 ± 3.1 years old (range 10—21 years old) were analyzed. Mean follow-up was 32.1 months. Defects were located on the patella in 25 knees, and trochlea in 11 knees (Figure 1). There were no bipolar lesions in the cohort. Mean defect size was 2.47 cm2. Twenty-four knees (66.7%) were graded either ‘normal’ or ‘nearly normal’, and 28 knees (77.8%) had greater than 50% of the defect filled on follow-up imaging. Return to sport rates among patients who participated in a sport preoperatively was 100%.Conclusion:Restoration of patellofemoral chondral defects in young patients with particulated juvenile allograft can be performed with satisfactory short-term efficacy, excellent postoperative MRI appearance, and very high rates of return to sport.Tables/Figures:Figure 1.PJAC Surgical Cases. (A) – (C) A patient with recurrent patellofemoral instability (A) Arthroscopic image demonstrating full-thickness defect at inferior portion of patella. (B) Defect bed prepared with vertical walls. (C) PJAC implanted, set and margins sealed with fibrin glue to achieve congruity with adjacent cartilage. (D) — (F) A patient with JOCD (D) Large crater defect of lateral trochlea, friable and easily removed with probe. (E) Approximately 2 x 1.5 cm lesion curetted down to layer of subchondral bone. (F) Initial PJAC placement over bed of fibrin glue. (G) — (I) A patient with recurrent patellofemoral instability. (G) Pre-operative axial T2 MRI demonstrating displaced patella chondral fragment (yellow arrow) and resulting defect (H) Post-operative axial T2 MRI at 1 year demonstrating 75% fill (white arrow). (I) Arthroscopic image of PJAC graft at 18-months post-operative during removal of hardware surgery, demonstrating excellent fill, and some small fraying cartilage, which was gently debrided.

Magnetic Resonance Imaging Evaluation of Patellofemoral Joint.

Patellofemoral pain is the leading cause of knee pain in young adults. Magnetic resonance imaging plays an important role in early diagnosis of patellofemoral joint pathology. This study was carried out to evaluate the patellofemoral joint using magnetic imaging resonance and describe various predisposing factors for patellofemoral instability. The study was carried in Department of Radiology, BPKIHS over a period of six months from February 2020 to August 2020. All patients with clinical diagnosis of patellar instability were included and Magnetic resonance imaging was done using standard knee protocol and findings were noted on structured proforma. Analysis was done using statistical package for the social sciences version 20 applying simple descriptive statistical methods. A total of 60 patients who underwent MRI knee were analyzed, out of which 28(46.7%) patients were male while 32(53.3%) patients were female. 44 patients (58.3%) had various predisposing factors for patellar instability. The commonest predisposing factor was patellar subluxation (73.3%) followed by abnormal trochlear groove angle (58.3%) and patellar translation (increased tibia tubercle trochlear groove distance) (53.3%). Various MRI findings in our study were bone contusion (28 cases,46.7%), joint effusion (36 cases,60%), medial patellofemoral ligament injury (11cases ,18.3%), erosion of patellar cartilage (5 cases,8.3%), femoral cartilage erosion (3 cases,5%),loose bodies (2 cases,3.3%), subchondral edema (3 cases,5%) and meniscus injury (18 cases,30%). Magnetic resonance imaging is not only useful in assessing lesions of the bone, cartilage and ligaments of patellofemoral joint but also enables detection of various predisposing factors for patellofemoral instability.

Early patellofemoral articular cartilage degeneration in a rat model of patellar instability is associated with activation of the NF-\u03baB signaling pathway

BackgroundPatellar instability (PI) often increases the possibility of lateral patellar dislocation and early osteoarthritis. The molecular mechanism of early articular cartilage degeneration during patellofemoral osteoarthritis (PFOA) still requires further investigation. However, it is known that the NF-κB signaling pathway plays an important role in articular cartilage degeneration. The aim of this study was to investigate the relationship between the NF-κB signaling pathway and patellofemoral joint cartilage degeneration.MethodsWe established a rat model of PI-induced PFOA. Female 4-week-old Sprague-Dawley rats (n = 120) were randomly divided into two groups: the PI (n = 60) and control group (n = 60). The distal femurs of the PI and control group were isolated and compared 4, 8, and 12 weeks after surgery. The morphological structure of the trochlear cartilage and subchondral bone were evaluated by micro-computed tomography and histology. The expression of NF-κB, matrix metalloproteinase (MMP)-13, collagen X, and TNF-ɑ were evaluated by immunohistochemistry and quantitative polymerase chain reaction.ResultsIn the PI group, subchondral bone loss and cartilage degeneration were found 4 weeks after surgery. Compared with the control group, the protein and mRNA expression of NF-κB and TNF-ɑ were significantly increased 4, 8, and 12 weeks after surgery in the PI group. In addition, the markers of cartilage degeneration MMP-13 and collagen X were more highly expressed in the PI group compared with the control group at different time points after surgery.ConclusionsThis study has demonstrated that early patellofemoral joint cartilage degeneration can be caused by PI in growing rats, accompanied by significant subchondral bone loss and cartilage degeneration. In addition, the degeneration of articular cartilage may be associated with the activation of the NF-κB signaling pathway and can deteriorate with time as a result of PI.

Do Bone-Patellar Tendon-Bone ACL-Reconstructed Knees Have More Signs of Patellofemoral Posttraumatic Osteoarthritis Than Their Uninjured Contralateral Knees at 2 Years?

Background:The prevalence of patellofemoral joint (PFJ) osteoarthritis ranges from 8% to 47% at 7 to 10 years after anterior cruciate ligament reconstruction (ACLR) using bone–patellar tendon–bone (BTB) autograft. In performing BTB ACLR, some hypothesize that either trauma caused by harvest of the BTB autograft or altered biomechanics contributes to PFJ posttraumatic osteoarthritis.Purpose/Hypothesis:To determine whether knees with ACLR using a BTB autograft show early signs of posttraumatic osteoarthritis as compared with the contralateral uninjured knee 2 years after ACLR. We hypothesized that a BTB autograft will not increase the prevalence of PFJ osteoarthritis.Study Design:Cohort study; Level of evidence, 3.Methods:Bilateral knee 3-T magnetic resonance imaging (MRI) scans were collected in 57 patients (mean age, 20.3 years; 28 men) from a single site at a minimum of 2 years after ACLR. Structural MRI assessment of the knees was performed using the MRI Osteoarthritis Knee Score semiquantitative scoring system by a board-certified musculoskeletal radiologist. The presence of cartilage defects in the patellofemoral compartment was compared between the reconstructed and contralateral uninjured knees using logistic regression analyses.Results:There were no significant differences in the prevalence of cartilage defects (full thickness or any thickness) in the PFJ between the BTB ACLR knees and the contralateral control knees: 38.6% of BTB ACLR knees had PFJ cartilage defects versus 31.6% of contralateral control knees (P > .391). The 95% CI for the difference between these groups was –9.0% to 23.0%.Conclusion:When comparing BTB ACLR knees with the uninjured contralateral knees in the study patients, we failed to observe statistically significant differences in the prevalence of PFJ cartilage lesions of full thickness or any thickness. These results should be used in shared decision-making with athletes when choosing the appropriate autograft during reconstruction. Our wide 95% CIs secondary to a smaller sample size demonstrate a need for larger studies in this area to more accurately describe the difference between the operative and contralateral knees.

Patellofemoral alignment, morphology and structural features are not related to sitting pain in individuals with patellofemoral pain

BackgroundSitting-related pain is a common feature of patellofemoral pain (PFP). However, little is known regarding features associated with sitting-related PFP. The aim of this study was to determine whether sitting-related PFP is associated with patellofemoral alignment, morphology and structural magnetic resonance imaging (MRI) features of the patellofemoral joint (cartilage lesions, bone marrow lesions, fat pad synovitis). Methods133 individuals with PFP were included from two unique but similar cohorts. Participants were classified into one of three groups based on their response to item 8 of the Anterior Knee Pain Scale: (i) problems with sitting; (ii) sitting pain after exercise; and (iii) no difficulty with sitting. All participants underwent 3T Magnetic Resonance Imaging (MRI) to enable: (i) scoring of structural features of the patellofemoral joint with MRI Osteoarthritis Knee Score (MOAKS); and (ii) patellofemoral alignment and morphology measurements using standardised methods. The association of sitting pain to bony alignment, morphology and MOAKS features were evaluated using multinomial logistic regression (adjusted for age, sex, BMI; reference group = no difficulty with sitting). Results82 (61.7%) participants reported problems with sitting, and 24 (18%) participants reported sitting pain after exercise. There were no significant associations between the presence of sitting pain and any morphology, alignment or structural characteristics. ConclusionsFindings indicate that PFP related to sitting is not associated with patellofemoral alignment, morphology, or structural MRI features of the patellofemoral joint. Further research to determine mechanisms of sitting-related PFP, and inform targeted treatments, are required.

Does patellofemoral osteoarthritis affect functional outcomes and survivorship after medial unicompartmental knee arthroplasty? A meta-analysis

PurposeThe argument that patellofemoral osteoarthritis (PFOA) is a contraindication to unicompartmental knee arthroplasty (UKA) remains to be resolved. The purpose of this study was to perform a meta-analysis to determine whether PFOA affects functional outcomes and survivorship after medial UKA.MethodsA literature search was performed in PubMed, Medline, Cochrane Library and Web of science to identify studies published in English (the last search was updated on June 1, 2020). The primary outcome measure was the Oxford Knee Score (OKS), whereas the secondary outcomes included range of motion (ROM) and the revision rate. Patients with patellofemoral joint narrowing or cartilage lesions as assessed intraoperatively or by radiography were assigned to the PFOA group.ResultsA total of 8 studies involving 3504 patients and 3975 knees were included in this meta-analysis. No patients had a severe lateral patellar groove. The results showed that there was no significant difference in the OKS, revision rate and ROM between PFOA patients and patients without PFOA.ConclusionsNo significant difference in functional outcomes and survivorship was found between patients with and without PFOA. Patients with PFOA assessed by radiographs or intraoperatively but without a lateral patellar groove should be considered candidates for medial UKA.