Femoral Articular Cartilage Research Articles

Ultrasonographic assessment of femoral cartilage thickness in patients with and without uveitis in Behçet's disease.

The objective for this study is to evaluate the femoral cartilage thickness in patients with/without uveitis in Behçet's disease (BD). Patients with BD aged 18-70years were included. The demographic and clinical characteristics of the patients were recorded. The thickness of femoral articular cartilage was measured with musculoskeletal ultrasound. Cartilage thickness was measured bilaterally from the central points of medial condyle (MFC), lateral condyle (LFC), and intercondylar area (ICA). 20 patients with uveitis [uveitis (+)] and 20 patients without uveitis [uveitis (-)] were included. Both right and left MFC and LFC had statistically significant thinner cartilage in uveitis (+) group (p < 0.05). For the ICA, uveitis (+) patients had thinner femoral cartilage than uveitis (-) patients; however, in the left side, statistically significance could not be detected. Femoral cartilage was thinner in uveitis (+) patients than in uveitis (-) patients in BD. This relationship between uveitis and femoral cartilage thickness may be helpful in the prevention and early treatment of cartilage degeneration.

Effects of a knee valgus unloader brace on medial femoral articular cartilage deformation following walking in varus-aligned individuals

BackgroundKnee varus alignment may increase loading in the medial tibiofemoral compartment, which can increase strain on the articular cartilage. Knee valgus unloader braces seek to reduce loading through the medial femoral compartment, but their effects on cartilage characteristics during dynamic tasks have not been evaluated. ObjectiveTo determine the effects of a knee valgus unloader brace on medial femoral articular cartilage deformation following a single 5000-step walking protocol in individuals with varus-knee alignment. MethodsTwenty-four healthy individuals (63% female, BMI = 22 ± 3 kg/m2, age = 21 ± 3 years) completed two testing sessions (braced and unbraced) separated by one week. During both sessions, femoral cartilage ultrasound images were acquired prior to and following a 5000-step treadmill walking protocol at self-selected speed. Percent change scores in medial cartilage cross-sectional area (MCCA) were calculated and used as the primary outcome, and compared between the braced and unbraced conditions. ResultsThere was no difference in percent change of MCCA between conditions (braced = −2.77%, unbraced = −3.15%, p = 0.699). Individuals whose cartilage deformed more than a previously established minimal detectable change (MDC ≥ 1.58 mm2) deformed less during the braced condition (braced = −2.94%, unbraced = −6.34%, p = 0.028), compared to individuals who did not deform greater than the MDC (n = 15, braced = −2.67%, unbraced = −1.23%, p = 0.210). ConclusionsThere was no significant difference in MCCA percent change between the braced and unbraced conditions across the entire cohort; yet a valgus unloader braces may serve as a potential intervention strategy for reducing articular cartilage deformation in certain varus-aligned individuals who normally undergo measurable deformation during walking.

Efficacy and Safety of a Stimulator Using Low-Intensity Pulsed Ultrasound Combined with Transcutaneous Electrical Nerve Stimulation in Patients with Painful Knee Osteoarthritis.

Objective Studies regarding the combination of ultrasound and transcutaneous electrical nerve stimulation (TENS) are rarely reported. In this study, we aimed to elucidate the efficacy and safety of a stimulator using low-intensity pulsed ultrasound (LIPUS) combined with TENS in patients with painful knee osteoarthritis (OA). We evaluated the effectiveness of this therapy against pain, physical function, and cartilage regeneration. Moreover, we aim to prove the superiority of the effects of LIPUS combined with TENS therapy compared with only TENS therapy. Methods Of the 40 included patients, aged 45–85 years with painful knee OA, 20 patients received only TENS therapy and 20 patients received LIPUS combined with TENS therapy for 8 weeks (a total of more than 80 treatment sessions). We evaluated visual analogue scale (VAS), Western Ontario and McMaster Universities (WOMAC) osteoarthritis index, MOS 36-Item Short-Form Health Survey (SF-36), and femoral articular cartilage (FAC) thickness. The evaluation was performed at three visits: visit 1 (V1, pretreatment, within 28 days after screening), visit 2 (V2, posttreatment period 1, ±3 days after treatment), and visit 3 (V3, posttreatment period 2, 21 ± 3 days after treatment). Results We expected that LIPUS combined with TENS therapy would be superior to only TENS therapy. However, there was no significant difference between the two therapies. In the within-group comparison, both treatments (only TENS therapy and LIPUS with TENS therapy) demonstrated statistical differences from baseline values for pain and physical function outcomes. FAC thickness showed no significant differences after treatment in both groups. Conclusion The effects of a stimulator using LIPUS with TENS on pain relief and functional improvement were not superior to the only TENS therapy. Cartilage regeneration, which was expected as an additional benefit of LIPUS, was also not significantly evident. Therefore, further investigation is warranted to determine whether the combination therapy is beneficial. This trial is registered with KCT0003883.

Biplanar ultrasonografik incelemenin femoral artiküler kıkırdaktaki dejeneratif değişiklikleri saptamadaki tanı değeri

Aim: The aim of our study was to assess the diagnostic value of biplanar ultrasonography in detecting degenerative changes of femoral articular cartilage using magnetic resonance imaging as the reference method.Material and Methods: Femoral articular cartilage examination was performed with ultrasonography and magnetic resonance imaging in 40 patients with knee pain. Magnetic resonance imaging of the knees were carried out on a 1.5 T scanner with proton density weighted, fat suppressed sequence in three orthogonal planes. Ultrasonographic evaluations of the knees were performed in both longitudinal and transverse planes. Taking the findings of magnetic resonance imaging as a reference, the diagnostic effectiveness of biplanar US in detecting medial condylar, lateral condylar and intercondylar notch cartilage lesions were calculated.Results: The sensitivity of biplanar ultrasonography in detecting medial condylar, lateral condylar, and intercondylar notch cartilage lesions were 93.55%, 61.11%, and 53.85%, respectively. The specificity of the technique in detecting the lesions in these locations were 88.89%, 90.91%, and 100.00%, respectively. Conclusion: Ultrasonography is a relatively inexpensive, easily accessible and a non-invasive imaging tool. We found that biplanar ultrasonography is a reliable method in detecting medial condylar cartilage lesions in knee osteoarthritis, and we recommend using it for the purposes of screening and follow-up evaluation of medial type knee osteoarthritis where MRI is not accessible.

GC–MS method for metabolic profiling of mouse femoral head articular cartilage reveals distinct effects of tissue culture and development

The metabolic profile of cartilage is important to define as it relates to both normal and pathophysiological conditions. Our aim was to develop a precise, high-throughput method for gas/chromatography-mass/spectrometry (GC-MS) semi-targeted metabolic profiling of mouse cartilage. Femoral head (hip) cartilage was isolated from 5- and 15-week-old male C57BL/6J mice immediately after death for invivo analyses. In vitro conditions were evaluated in 5-week-old samples cultured ±10% fetal bovine serum (FBS). We optimized cartilage processing for GC-MS analysis and evaluated group-specific differences by multivariate and parametric statistical analyses. 55 metabolites were identified in pooled cartilage (4 animals per sample), with 29 metabolites shared between invivo and invitro conditions. Multivariate analysis of these common metabolites demonstrated that culturing explants was the strongest factor altering cartilage metabolism, followed by age and serum starvation. In vitro culture altered the relative abundance of specific metabolites; whereas, cartilage development between five and 15-weeks of age reduced the levels of 36 out of 43 metabolites >2-fold, especially in TCA cycle and alanine, aspartate, and glutamate pathways. In vitro serum starvation depleted six out of 41 metabolites. This study describes the first GC-MS method for mouse cartilage metabolite identification and quantification. We observed fundamental differences in femoral head cartilage metabolic profiles between invivo and in vitro conditions, suggesting opportunities to optimize in vitro conditions for studying cartilage metabolism. In addition, the reductions in TCA cycle and amino acid metabolites during cartilage maturation illustrate the plasticity of chondrocyte metabolism during development.

The Pattern of Acetabular Cartilage Wear Is Hip Morphology-dependent and Patient Demographic-dependent.

The Pattern of Acetabular Cartilage Wear Is Hip Morphology-dependent and Patient Demographic-dependent.

Acute Effects of Walking on the Deformation of Femoral Articular Cartilage in Older Adults.

Although discomfort during walking is a common complaint in individuals with knee osteoarthritis (OA), how an acute bout of walking affects femoral cartilage remains unclear. Current literature has suggested that frontal plane knee malalignment (ie, varus and valgus) is associated with the initiation and/or progression of knee OA. However, the association between knee alignment and femoral cartilage deformation after an acute bout of loading has not yet been investigated. This study was aimed to compare the acute effects of walking on femoral cartilage deformation between older adults with and without knee OA. We also examined the association between frontal plane knee alignment and loading-induced femoral cartilage deformation. Ten persons without OA (Kellgren Lawrence grading = 0 or 1; 5 females and 5 males; 55.0 [1.8] years of age; 78.8 [14.1] kg; 1.8 [0.2] m) and 9 persons with OA (Kellgren Lawrence grading ≥2; 4 females and 5 males; 55.6 [4.5] years of age; 97.4 [15.0] kg; 1.7 [0.1] m) participated. Each participant underwent magnetic resonance imaging before and immediately after 30 minutes of fast walking at 3 to 4 miles per hour. To obtain cartilage deformation postwalking, the medial and lateral femoral cartilage of the weight-bearing areas was segmented on participants' magnetic resonance imaging. Cartilage thickness was quantified by computing the average perpendicular distance between opposing voxels defining the edges of the femoral cartilage. Cartilage deformation of the medial and lateral femurs was defined as the percent changes in cartilage thickness after walking. Frontal plane knee alignment was obtained by measuring the angle between the long axes of femur and tibia. Independent t tests were used to compare cartilage deformation between the 2 groups. Pearson correlation coefficients were used to assess the association between cartilage deformation and knee alignment. There was no significant difference in cartilage deformation between the OA and control groups in lateral (P = .69) or medial (P = .87) femur. A significant correlation was found between lateral femoral cartilage deformation and increased knee valgus alignment (r = 0.497; P = .03). No difference was found between medial femoral cartilage deformation and frontal plane knee alignment (r = 273; P = .26). This is the first study comparing the acute effects of walking on femoral cartilage deformation between older adults with and without knee OA. Although there was not a difference in walking-induced femoral cartilage deformation between the OA and control groups, knee valgus was related to lateral femoral cartilage deformation after walking. Our findings suggested that walking exercises may be used safely in older adults without knee malalignment.

Femoral Chondral Lesions Increase in Severity with Aging Equally Between the Sexes and Present in Comparable Locations

ObjectiveThe objective of this study was to determine if visible, femoral chondral lesions on cadaveric knee joints exacerbate differently with aging between the sexes.Methods85 cadaveric femurs were assessed for chondral pathology overlying the femoral condyles and patellar fossa using a 0–4 qualitative grading scale for gross signs of osteoarthritis (OA). Each specimen was blinded to four raters and the raters' scores were averaged to provide each specimen a Disease Severity Score (DSS).ResultsSpecimens 80+ years old (N=22) had an average DSS of 3.19 ± 0.69 compared to a DSS of 2.7 ± 0.85 and a DSS of 2.52 ± 0.95 for specimens 70–79 years old (N=42) and specimens below 70 years old (N=22), respectively. The DSS for the 80+ years old population was significantly greater than the DSS of the 70–79 years old population (p &lt; 0.05) and the below 70 years old population (p &lt; 0.05). Specimens that scored a DSS of 2 and above, representing mild OA to severe OA, were assessed for their specific site of most severe degeneration. The most severe degeneration on the femoral articular cartilage was consistently on the patellar fossa. This degeneration was seen in 45% of specimens below 70 years old, 60% of specimens 70–79 years old and 50% of specimens above the age of 80 years old. The lateral condyle was the second most degenerated region in the below 70 years old specimens (27%). The medial condyle became the second most degenerated region in the 70–79 years old specimens (38%) and the above 80 years old specimens (68%). The males and females in the above 80 years old population each displayed a 2:7 ratio for lateral condyle vs. medial condyle as the site of most severe deterioration.ConclusionsThis study displayed increased severity of OA on the femoral condyles with aging yet, there was no difference between the sexes in the severity or location of degeneration. With increased propensity to develop shearing forces in the knee based on cruciate ligament thinning or muscular atrophy around the joint the medial joint can experience increased degeneration. Currently, over 2/3s of the American population is overweight and obesity sways tibiofemoral compression forces to the lateral respects of the joint. When patients are over the age of 80 their muscles supporting the joint have atrophied and can no longer resist degenerative shearing forces at the knee. Whereas patients between the ages of 70–79 appear to represent a split population where approximately half of this population may be affected by obesity and the other half by muscular atrophy. It is recommended that public health advisory committees target these patients earlier in adult life with recommendations to increase their muscle mass around the knee joint and reduce obesity. The most prevalent sites of degeneration per each age group should be considered as research on stem cell therapy for synovial joint pathology continues to increase.Support or Funding InformationInternal grant from Rocky Mountain University of Health ProfessionsThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Mineralogical assessment of the femoral heads and articular cartilage of the femur in patients with avascular necrosis (AVN)

Mineralogical assessment of the femoral heads and articular cartilage of the femur in patients with avascular necrosis (AVN)

Recurrent Patellar Instability: Implications of Preoperative Patellar Crepitation on the Status of the Patellofemoral Articular Cartilage.

The purpose of the study was to quantify the frequency, severity, and location of patellofemoral (PF) articular cartilage changes recurrent patellar instability treated surgically in patients with preoperative clinical patellar crepitation. A single-surgeon database was queried for all knees with recurrent patellar instability between 3/2000 and 6/2012 (n=214). Only knees which underwent knee arthroscopy during the surgical treatment were included (n=148). PF articular cartilage condition was assessed arthroscopically. There were 148 knees in 130 patients (mean age, 16 y), which met inclusion criteria. There were 93 females and 37 males. Diagnoses were dislocations [122 (82.4%)] and subluxations (26). Preoperatively 28 knees (18.9%) had PF crepitation. Statistical analysis demonstrated preoperative PF crepitation was correlated with medial patellar facet lesions (P=0.0022) and were 3.6 times more likely to have medial patellar facet lesions. Crepitation was correlated with the higher outerbridge (OB) patellar grades (P<0.0001) and larger patellar lesion size (P=0.0021). At arthroscopy 89 knees (60.5%) had patellar articular cartilage damage with a mean OB grade of 1.3 (0 to 4) and mean size of 93.2 mm (0 to 750). The femoral articular cartilage was identified in 29 knees (19.7%) with a mean OB grade of 0.44 (0 to 4). PF articular damage was present in 63% of knees, which were surgically treated for patellar instability. The patella was involved in 61% (mean, 129 mm) and femoral trochlea in 20% (mean 166 mm) of knees. Knee with preoperative PF crepitation (20% of cohort) more commonly had medial patellar facet lesions with higher OB grades, and larger patellar lesion size than knees without preoperative crepitation. Because of the high frequency of patellar (83%) and femoral (36%) articular damage documented at the time of surgical reconstruction, visualization of the PF joint is recommended when knees have preoperative PF crepitation. Level IV.

The Effect of Lateral Opening Wedge Distal Femoral Varus Osteotomy on Tibiofemoral Contact Mechanics Through Knee Flexion

Background: Lateral opening wedge distal femoral osteotomy (DFO) unloads a diseased lateral compartment of the knee in patients with genu valgum. To the best of our knowledge, there are no biomechanical studies investigating the effect of knee flexion on contact pressure and area after DFO. Hypothesis: As knee flexion angles increase, DFO will be less effective at unloading the lateral compartment of the knee. Study Design: Controlled laboratory study. Methods: Lateral opening wedge DFO was performed, correcting a mean of 7°, in 10 cadaveric knees using plate fixation. Tibiofemoral contact pressure was measured in 0°, 15°, 30°, 45°, 60°, and 75° of knee flexion before and after osteotomy using electronic sensors. Peak contact pressure (PCP), mean contact pressure (MCP), and contact area were measured for each condition. Anatomic dissection quantified the tibiofemoral contact position on the distal femur in all degrees of flexion. Mixed-effects regression analyses were used to compare the change in variables before and after osteotomy and between flexion angles. Results: One sample had to be excluded because of tibiofemoral arthritis. MCP decreased in the lateral compartment after DFO throughout all degrees of flexion (all P < .05) but to the greatest extent in 0° of flexion. When examining the percentage of MCP in the lateral compartment, this decreased after DFO at 0° (70.4% to 40.0%; P < .001), 15° (65.1% to 52.1%; P < .001), 30° (60.7% to 52.0%; P = .003), 45° (55.8% to 49.7%; P = .033), and 60° (51.9% to 44.2%; P = .010) but not at 75° (50.2% to 45.3%; P = .112). PCP decreased in the lateral compartment after DFO at 0° (2.41 to 1.34 MPa; P < .001), 15° (2.50 to 1.81 MPa; P < .001), 30° (2.28 to 1.93 MPa; P = .039), 45° (2.21 to 1.73 MPa; P = .005), 60° (2.15 to 1.71 MPa; P = .009), and 75° (1.95 to 1.49 MPa; P = .012). The percentage of contact area decreased in the lateral compartment in full extension (68.7% to 48.1%; P = .007) but not at any other degree of flexion (all P > .05). Conclusion: DFO decreased lateral compartment pressure. However, it had the greatest effect in full knee extension. Clinical Relevance: DFO decreased contact pressure in the lateral compartment but more effectively decreased contact pressure in the more anterior aspects of the femoral articular cartilage.

Particulated Juvenile Articular Cartilage (PJAC) Allograft for Treatment of Lateral Femoral Condyle defect in High-Performance Athletes

Background: A relatively new technology for the treatment of high grade articular cartilage lesions is the implantation of particulated articular cartilage obtained from a juvenile allograft donor (PJAC).1-2 Previous studies have reported the ability of juvenile chondrocytes to migrate from cartilage explants after being secured in a cartilage defect.3 There is little in the literature to use as a reference with respect to the use of PJAC for high grade articular cartilage lesion of the lateral femoral condyle after a failure of treatment with a microfracture in the high level athlete. Objective: The aim of this report is to describe the technique of PJAC transplantation for the treatment of chondral lesions of the lateral femoral condyle and to report the short term outcomes in the high performance athlete. Methods: We present a case report of two patients who were treated in our clinic in December 2014. Case 1: 16 year old female Division 1 university soccer player, who one year prior to our index surgery underwent microfractures of a symptomatic lateral femoral condyle articular cartilage lesion without relief. Cae 2: 29 year old male professional tennis player (case 2) with a recurrent, symptomatic chondral defect on the lateral femoral condyle. The player had undergone multiple arthroscopic procedures on the same knee following an injury sustained while playing in the Australian Open, including a surgery 8 months prior to our index operation that had included lateral meniscal tear repair and microfractures. PJAC procedure consists of a minimal debridement and chondroplasty, performed arthroscopically. For these central lateral femoral condyle lesions, a mini-arthrotomy is created along the lateral parapatellar longitudinal axis over a length of about 3 cm. With the chondral defect localized and prepared, a thin fresh layer of fibrin glue is then applied. The PJAC graft is equally distributed in the defect with space in between the fragments so as not over-fill the defect. Then, a new fibrin glue layer is placed to cover the graft. The overall construct remains just below the level of the normal articular surface. The knee is cycled through the range of motion to ensure that the tissue construct is stable. We present images of the cartilage defect after debridement and the allograft implantation procedure. In addition we will submit an instructional video performed on a knee specimen. Results: Outcomes measured were: IKDC, Lysholm, and Tegner knee scores together with arc of motion of the joint. After 28 months follow up, patients had gained complete range of motion and significantly decreased pain. Improvement for each outcome measure used is reported. Conclusions: PJAC transplantation offers pain relief and improved short term outcomes in high level performance athletes. Both of our patients are back to practicing their sport with notable improvement in symptoms. No complications have been noted. Long-term data is not yet available.

Effects of Proud Large Osteochondral Plugs on Contact Forces and Knee Kinematics: A Robotic Study

Background: Osteochondral allograft (OCA) transplantation is used to treat large focal femoral condylar articular cartilage defects. A proud plug could affect graft survival by altering contact forces (CFs) and knee kinematics. Hypothesis: A proud OCA plug will significantly increase CF and significantly alter knee kinematics throughout controlled knee flexion. Study Design: Controlled laboratory study. Methods: Human cadaver knees had miniature load cells, each with a 20-mm-diameter cylinder of native bone/cartilage attached at its exact anatomic position, installed in both femoral condyles at standardized locations representative of clinical defects. Spacers were inserted to create proud plug conditions of +0.5, +1.0, and +1.5 mm. CFs and knee kinematics were recorded as a robot flexed the knee continuously from 0° to 50° under 1000 N of tibiofemoral compression. Results: CFs were increased significantly (vs flush) for all proudness conditions between 0° and 45° of flexion (medial) and 0° to 50° of flexion (lateral). At 20°, the average increases in medial CF for +0.5-mm, +1-mm, and +1.5-mm proudness were +80 N (+36%), +155 N (+70%), and +193 N (+87%), respectively. Corresponding increases with proud lateral plugs were +44 N (+14%), +90 N (+29%), and +118 N (+38%). CF increases for medial plugs at 20° of flexion were significantly greater than those for lateral plugs at all proudness conditions. At 50°, a 1-mm proud lateral plug significantly decreased internal tibial rotation by 15.4° and decreased valgus rotation by 2.5°. Conclusion: A proud medial or lateral plug significantly increased CF between 0° and 45° of flexion. Our results suggest that a medial plug at 20° may be more sensitive to graft incongruity than a lateral plug. The changes in rotational kinematics with proud lateral plugs were attributed to earlier contact between the proud plug’s surface and the lateral meniscus, leading to rim impingement with decreased tibial rotation. Clinical Relevance: Increased CF and altered knee kinematics from a proud femoral plug could affect graft viability. Plug proudness of only 0.5 mm produced significant changes in CF and knee kinematics, and the clinically accepted 1-mm tolerance may need to be reexamined in view of our findings.

Effects of long-term high-load exercise on the anatomy of the hip joints: a preliminary report.

The aim of this study was to assess the impact of different sports on hip joint anatomic parameters in athletes. This was a cross-sectional study of eight male trampolinists, eight male weightlifters, and eight male volunteers enrolled in July 2014. Hip joint anatomic parameters were measured from plain radiographs taken at the level of the lesser trochanter center. Data were compared between groups using the χ-test or one-way analysis of variance with the Bonferroni post-hoc test. There were no significant differences among groups in age, height, or weight. Compared with the controls, trampolinists showed higher pelvic width, femoral neck length, metaphyseal width (T0), width 20 mm above T0 (T+20), width 20 mm below T0 (T-20) and center edge (CE) angle, and lower head-trochanter ratio, joint space, neck-shaft angle, and articular cartilage angle (P<0.05). Compared with the controls, weightlifters showed lower pelvic femoral index, joint space, length of femoral neck, eccentricity, neck-shaft, and AC angle, and higher pelvic width, femoral head radius, and CE angle (P<0.05). Compared with trampolinists, weightlifters showed higher head-trochanter ratio and femoral head radius, and lower pelvic femoral index, femoral neck length, eccentricity, T0, T+20, T-20, neck-shaft angle, CE angle, and articular cartilage angle (P<0.05). Long-term high-intensity training causes adaptive changes in the hip joint structure that differ between trampolinists and weightlifters.

An extended OpenSim knee model for analysis of strains of connective tissues

BackgroundOpenSim musculoskeletal models provide an accurate simulation environment that eases limitations of in vivo and in vitro studies. In this work, a biomechanical knee model was formulated with femoral articular cartilages and menisci along with 25 connective tissue bundles representing ligaments and capsules. The strain patterns of the connective tissues in the presence of femoral articular cartilage and menisci in the OpenSim knee model was probed in a first of its kind study.MethodsThe effect of knee flexion (0°–120°), knee rotation (− 40° to 30°) and knee adduction (− 15° to 15°) on the anterior cruciate, posterior cruciate, medial collateral, lateral collateral ligaments and other connective tissues were studied by passive simulation. Further, a new parameter for assessment of strain namely, the differential inter-bundle strain of the connective tissues were analyzed to provide new insights for injury kinematics.ResultsACL, PCL, LCL and PL was observed to follow a parabolic strain pattern during flexion while MCL represented linear strain patterns. All connective tissues showed non-symmetric parabolic strain variation during rotation. During adduction, the strain variation was linear for the knee bundles except for FL, PFL and TL.ConclusionsStrains higher than 0.1 were observed in most of the bundles during lateral rotation followed by abduction, medial rotation and adduction. In the case of flexion, highest strains were observed in aACL and aPCL. A combination of strains at a flexion of 0° with medial rotation of 30° or a flexion of 80° with rotation of 30° are evaluated as rupture-prone kinematics.

3D-Printed Patient-Specific ACL Femoral Tunnel Guide from MRI.

Background:Traditional ACL reconstruction with non-anatomic techniques can demonstrate unsatisfactory long-term outcomes with regards instability and the degenerative knee changes observed with these results. Anatomic ACL reconstruction attempts to closely reproduce the patient's individual anatomic characteristics with the aim of restoring knee kinematics, in order to improve patient short and long-term outcomes. We designed an arthroscopic, patient-specific, ACL femoral tunnel guide to aid anatomical placement of the ACL graft within the femoral tunnel.Methods:The guide design was based on MRI scan of the subject's uninjured contralateral knee, identifying the femoral footprint and its anatomical position relative to the borders of the femoral articular cartilage. Image processing software was used to create a 3D computer aided design which was subsequently exported to a 3D-printing service.Results:Transparent acrylic based photopolymer, PA220 plastic and 316L stainless steel patient-specific ACL femoral tunnel guides were created; the models produced were accurate with no statistical difference in size and positioning of the center of the ACL femoral footprint guide to MRI (p=0.344, p=0.189, p=0.233 respectively). The guides aim to provide accurate marking of the starting point of the femoral tunnel in arthroscopic ACL reconstruction.Conclusion:This study serves as a proof of concept for the accurate creation of 3D-printed patient-specific guides for the anatomical placement of the femoral tunnel during ACL reconstruction.

Human umbilical cord Wharton's jelly mesenchymal stem cells combined with an acellular cartilage extracellular matrix scaffold improve cartilage repair compared with microfracture in a caprine model

As a novel and promising seed cell, human umbilical cord Wharton's jelly mesenchymal stem cells (hWJMSCs) are widely applied in tissue engineering. However, whether hWJMSCs can better repair and regenerate the articular cartilage in big animals than microfracture (MF, a predominant clinical treatment strategy for damaged cartilage) is unclear. Evaluation of the validity, and safety of hWJMSCs in a caprine model with a full-thickness femoral condyle articular cartilage defect, compared with MF is required. After cultivation and identification, hWJMSCs were seeded in an acellular cartilage extracellular matrix (ACECM)-oriented scaffold to construct cell-scaffold complex. Six goats with full-thickness femoral condyle articular cartilage defects were randomized to MF (microfracture group, MFG) and cell-scaffold complexes (experimental group, EG). At 2 and 4 weeks, joint fluid was used to assess immuno-inflammatory responses. At 6 and 9 months, all goats were euthanized for assessment of morphology, and magnetic resonance imaging (MRI), histology staining, and evaluation of the elasticity modulus and glycosaminoglycan (GAG) contents of the repaired regions. There were no significant differences between the two groups in immuno-inflammatory parameters. MRI demonstrated higher-quality cartilage and complete subchondral bone at defect sites in the EG at 9 months. Histological staining showed that extracellular cartilage, cartilage lacuna and collagen type II levels were higher in the EG compared to the MFG, while the EG exhibited a higher elasticity modulus. The hWJMSCs-ACECM scaffold complex achieved better quality repair and regeneration of hyaline cartilage without cartilage-inducing factor, while retaining the structure and functional integrity of the subchondral bone, compared with MF.

Topographic Analysis of the Distal Femoral Condyle Articular Cartilage Surface: Adequacy of the Graft from Opposite Condyles of the Same or Different Size for the Osteochondral Allograft Transplantation.

To analyze the topography of the opposite condyle to treat focal femoral condyle articular defects with an osteochondral allograft (OCA). Three groups were created: Group 1, same condyle with same width; Group 2, opposite condyle with same width; Group 3, opposite condyle with different width. Computed tomography (CT) of 22 cadaveric femoral hemi-condyles was used to create 3-dimensional CT models that were exported into point-cloud models. Three zones of the donor condyle (anterior, middle, and posterior) were quantified. Four defect sizes were created (15, 18, 23, 25 mm) at the weight-bearing region. The defect was moved throughout each donor condyle zone and the least distance was calculated, defined as the shortest distance between the defect and the donor condyle. The mean least distance increased with larger defect size in all groups, yet there was a less than 0.2 mm difference in the least distance among defect sizes. The 15, 18, and 23 mm defect models in Group 1 exhibited greater least distances at the anterior than middle and posterior zones. The 15 mm defect model exhibited greater least distance at the anterior zone than posterior zone in Group 3. However, there was a less than 0.05 mm difference in the mean least distance between zones. There was no significant difference in the least distance between groups. OCAs from opposite condyles yield similar topographic matching to OCAs from the same condyles, suggesting that opposite condyles can be utilized. Clinical correlation and outcomes are necessary.

Topographical Variation of Human Femoral Articular Cartilage Thickness, T1rho and T2 Relaxation Times Is Related to Local Loading during Walking.

Early detection of degenerative changes in the cartilage matrix composition is essential for evaluating early interventions that slow down osteoarthritis (OA) initiation. T1rho and T2 relaxation times were found to be effective for detecting early changes in proteoglycan and collagen content. To use these magnetic resonance imaging (MRI) methods, it is important to document the topographical variation in cartilage thickness, T1rho and T2 relaxation times in a healthy population. As OA is partially mechanically driven, the relation between these MRI-based parameters and localized mechanical loading during walking was investigated. MR images were acquired in 14 healthy adults and cartilage thickness and T1rho and T2 relaxation times were determined. Experimental gait data was collected and processed using musculoskeletal modeling to identify weight-bearing zones and estimate the contact force impulse during gait. Variation of the cartilage properties (i.e., thickness, T1rho, and T2) over the femoral cartilage was analyzed and compared between the weight-bearing and non-weight-bearing zone of the medial and lateral condyle as well as the trochlea. Medial condyle cartilage thickness was correlated to the contact force impulse ( r = 0.78). Lower T1rho, indicating increased proteoglycan content, was found in the medial weight-bearing zone. T2 was higher in all weight-bearing zones compared with the non-weight-bearing zones, indicating lower relative collagen content. The current results suggest that medial condyle cartilage is adapted as a long-term protective response to localized loading during a frequently performed task and that the weight-bearing zone of the medial condyle has superior weight bearing capacities compared with the non-weight-bearing zones.

It is feasible to perform an all-epiphyseal double-bundle posterior cruciate ligament reconstruction in skeletally immature patients? A computer-aided modelling study

ObjectiveThe purpose of this study was to determine whether damage to the physis, articular cartilage, medial collateral ligament (MCL) and medial patellofemoral ligament (MPFL) can be avoided during femoral tunnel drilling in an anatomic, all-epiphyseal double-bundle (DB) reconstruction of the posterior cruciate ligament (PCL) in the skeletally immature knee using three-dimensional (3D) reconstruction modelling.MethodsCT scans of eight male skeletally immature cadaveric knee specimens between the ages 5 and 11 years were used to create eight 3D models of paediatric femurs. Using these 3D models, 5 mm, 6 mm and 7 mm tunnels were placed in the anatomic footprints of the anterolateral (AL) and posteromedial (PM) bundles, simulating an outside-in technique. Both full-length and a predetermined socket length were simulated in various trajectories to achieve the following goals: (1) avoid the femoral physis and periphyseal ring; (2) create adequate spacing (≥2 mm) between the tunnels to avoid significant tunnel convergence in the PCL footprint; (3) avoid articular cartilage of trochlea and medial condyle; and (4) avoid the femoral origin of the MCL and MPFL.ResultsIn all eight models, both tunnels could be placed in the PCL origin without damaging the physis, articular cartilage, MCL or MPFL. There was an adequate bone bridge (≥2 mm) between the two tunnels in ages 7–11 with a 6–7 mm AL tunnel and a 5–6 mm PM tunnel, as well as the 5-year-old model, using a 6 mm and 5 mm AL and PM tunnel, respectively.ConclusionThis computer-aided design model demonstrated that 5 mm, 6 mm and 7 mm all-epiphyseal tunnels can be placed within the footprint of the PCL while avoiding direct injury to the femoral physis, articular cartilage, MCL and MPFL. By understanding the location and trajectory of tunnel and socket placement, DB PCL reconstruction may be performed in skeletally immature knees without causing damage to the distal femoral physis and surface ligament footprints.Level of evidenceIV.