Changes In Patellofemoral Joint Research Articles

Contact area and pressure changes of patellofemoral joint during stair ascent and stair descent

PurposeTo investigate the differences of patellofemoral joint pressure and contact area between the process of stair ascent and stair descent.MethodsThe finite element models of 9 volunteers without disorders of knee (9 males) to estimate patellar cartilage pressure during the stair ascent and the stair descent. Simulations took into account cartilage morphology from magnetic resonance imaging, joint posture from weight-bearing magnetic resonance imaging, and ligament model. The three-dimension models of the patella, femur and tibia were developed with the medical image processing software, Mimics 11.1. The ligament was established by truss element of the non-linear FE solver. The equivalent gravity direction (-z direction) load was applied to the whole end of femur (femoral head) according to the body weight of the volunteers, and the force of patella was observed. A paired-samples t-test or Wilcoxon rank sum test to make comparisons between stair ascent and stair descent. Statistical analyses were performed using SPSS 22.0 using a P value of 0.05 to indicate significance.ResultsDuring the stair descent (knee flexion at 30°), the contact pressure of the patella was 2.59 ± 0.06Mpa. The contact pressure of femoral trochlea cartilage was 2.57 ± 0.06Mpa. During the stair ascent (knee flexion at 60°), the contact pressure with patellar cartilage was 2.82 ± 0.08Mpa. The contact pressure of the femoral trochlea cartilage was 3.03 ± 0.11Mpa. The contact area between patellar cartilage and femoral trochlea cartilage was 249.27 ± 1.35mm2 during the stair descent, which was less than 434.32 ± 1.70mm2 during the stair ascent. The area of high pressure was located in the lateral area of patella during stair descent and the area of high pressure was scattered during stair ascent.ConclusionThere are small change in the cartilage contact pressure between stair ascent and stair descent, indicating that the joint adjusts the contact pressure by increasing the contact area.

Surgical treatment of knee osteoarthritis focusing on the patellofemoral joint

Background: Surgical management of the osteoarthritic knee joint consists of osteotomies such as a high tibial osteotomy (HTO), uni-compartmental knee arthroplasty (UKA), and total knee arthroplasty (TKA). These surgeries mainly treat the tibiofemoral joint but can also have an impact on the patellofemoral (PF) joint. These changes in PF joint can affect the surgical outcome.Current Concepts: PF joint problems are relative contraindications in UKA. However, recent studies have reported that these problems do not markedly affect the result of UKA. During HTO, the patella height and tracking can change, affecting the PF joint problem. The effect of the PF joint can be minimized through various methods of closing wedge HTO or modified opening wedge (OW) HTO, such as retro-tubercular biplanar OWHTO. However, this method is controversial regarding its impact on clinical outcomes. In TKA, pain caused by PF joint problems can be reduced using techniques such as patella resurfacing, patelloplasty, and denervation; however, there is no clear consensus.Discussion and Conclusion: The surgical treatment of degenerative knee osteoarthritis has an impact on the PF joint, which can affect the outcome of surgery and vice versa. However, these impacts only occasionally cause clinical difference. Conclusively, these surgeries should be done by considering the PF joint because changes in the joint can affect the surgical outcome.

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.

Kinematic analysis of the load-response mechanism during stair descent in women with patellofemoral pain

Changes in patellofemoral joint (PFJ) stress are related to the development and course of PFJ dysfunctions. Different methods for PFJ stress calculation have been used, making the comparison of PFJ stress values across different studies difficult. The purpose of this study was to systematically review the methods for PFJ stress calculation and highlight the differences among the methods. A systematic literature search was conducted in Medline, Embase, CINAHL, SPORTDiscus and Web of Science databases. Included studies examined PFJ stress in subjects with or without musculoskeletal conditions. Of 12,670 identified studies, 53 were included, with a total of 1134 subjects evaluated. The main differences among the methods to calculate PFJ stress were: i) method to calculate PFJ contact area; ii) method to calculate a constant (coefficient k) that defines the relation between quadriceps force and PFJ reaction force; iii) the inclusion of adjustments for sagittal plane forces. Considerable variability in PFJ stress results was observed. The greatest PFJ stress value was 55.03 MPa during a dance jump and the lowest value was 1.9 MPa during walking at the speed of 1.4 m/s. Most studies applied methods which use data from previous studies. However, methods which use data from their own participants for most parts of the calculation might be preferred to minimize potential errors. When direct measures are not possible, a standard method could be applied to facilitate comparisons among studies.

Changes in patellofemoral and tibiofemoral joint cartilage damage and bone marrow lesions over 7 years: the Multicenter Osteoarthritis Study

To investigate changes in cartilage damage and bone marrow lesions (BMLs) on MRI in the patellofemoral and tibiofemoral joints (TFJs) over 7 years. The Multicenter Osteoarthritis (MOST) Study is a cohort study of persons aged 50-79 years at baseline with or at high risk for knee osteoarthritis (OA). Knees were eligible for the current study if they had knee MRI (1.0T) assessed for cartilage damage and BMLs at the baseline and 84-month visits. Knees were categorized as having MRI-detected structural damage (cartilage and BMLs) isolated to the patellofemoral joint (PFJ), isolated to the TFJ, mixed or no damage at baseline and 84-months. We determined the changes in PFJ and TFJ structural damage over 7 years and used logistic regression to assess the relation of baseline compartment distribution to incident isolated PFJ, isolated TFJ and mixed damage. Among 339 knees that had full-thickness cartilage loss isolated to the PFJ or TFJ at baseline, only 68 (20.1%) developed full-thickness cartilage loss in the other compartment while 271 (79.9%) continued to only have the initial compartment affected. Compared to knees without full-thickness cartilage damage (n=582), those with isolated TFJ and PFJ full-thickness cartilage damage had 2.7 (1.5, 4.9) and 5.8 (3.6, 9.6) times the odds of incident mixed full-thickness cartilage damage, respectively. Similar results were seen when using other definitions of MRI-defined structural damage. Most knees with structural damage at baseline do not develop it in the other compartment. Knees that develop mixed structural damage are more likely to start with it isolated to the PFJ.

Structural parameters of the vastus medialis muscle and its relationship to patellofemoral joint deterioration

Vastus medialis (VM) muscle dysfunction and abnormal limb alignment are commonly observed in patients who experience changes in patellofemoral joint (PFJ) function, leading many clinicians to assume that there is a direct relationship between VM structural parameters, leg alignment, and PFJ dysfunction. This study tested the hypothesis that there is a relationship between structural parameters of the VM muscle, limb alignment, and the location and severity of patellofemoral joint deterioration (PFJD). The dissection study used 32 limbs from 24 intact cadavers. Data were collected on limb alignment, angle of VM muscle fibers below the superior aspect of the patella, length of VM inserting on the medial aspect of the patella, and severity and location of PFJD. Parametric and nonparametric statistical analyses illustrated that PFJD was most commonly located on the middle third of the medial half of the patellar articular surface. The severity of PFJD did not vary with location. There was no significant correlation between any of VM insertion length, VM fiber angle, limb alignment, and PFJD location and severity lpar;r(2) < 0.34). The results of this study did not support the hypothesis of a relationship between structural parameters of the VM muscle, limb alignment, and the location and severity of PFJD in this subject group. Future research should examine the relationship between functional parameters of the entire quadriceps muscle group and PFJ dysfunction.

3D-T 1ρ-relaxation mapping of articular cartilage : In vivo assessment of early degenerative changes in symptomatic osteoarthritic subjects 1

Rationale and objectives To determine the in vivo feasibility of quantifying early degenerative changes in patellofemoral joint of symptomatic human knee using spin-lattice relaxation time in the rotating frame (T 1ρ) magnetic resonance imaging (MRI). Materials and methods All the MRI experiments were performed on a 1.5 T whole-body GE Signa clinical scanner using a custom built 15-cm diameter transmit-receive quadrature birdcage radiofrequency coil. The T 1ρ-prepared magnetization was imaged with a three-dimensional gradient-echo pulse sequence pre-encoded with a three-pulse cluster consisting of two hard 90° pulses and a low power spin-lock pulse. Quantitative T 1ρ relaxation maps of asymptomatic (n = 8 males), and six symptomatic human volunteers (four men, two women) were computed using a appropriate signal expression. Results All six symptomatic volunteers showed elevation in T 1ρ relaxation times when compared with asymptomatic subjects. In symptomatic population, the T 1ρ relaxation times varied from 63 ± 4 ms to 95 ± 12 ms (mean ± standard deviation) depending on the degree of cartilage degeneration. The increase in T 1ρ of symptomatic population was statistically significant (n = 6, P < .002) when compared with corresponding asymptomatic population. However, in asymptomatic population the relaxation times varied only from approximately 45 to 55 ms (n = 8, age range 22–45 years). Conclusion Preliminary results demonstrated the in vivo feasibility of quantifying early biochemical changes in symptomatic osteoarthritis subjects employing T 1ρ-weighted MRI on a 1.5 T clinical scanner. This study on limited number of symptomatic population shows that T 1ρ-weighted MRI provides a noninvasive marker for quantitation of early degenerative changes of cartilage in vivo. However, further studies are needed to correlate early osteoarthritis determined from arthroscopy with T 1ρ in a large symptomatic population.