Patellar Cartilage Lesions Research Articles

Osteochondral Autograft Transplantation for Symptomatic Full-thickness Patellar Cartilage Defects in Adolescents.

This study aimed to review the clinical, radiographic, and magnetic resonance imaging (MRI) outcomes of osteochondral autograft transplantation applied to patellar cartilage lesions of patients under 18 years of age. Data from nine consecutive patients were retrospectively analyzed for indications, preoperative complications, and clinical-radiographic outcomes. Patients were clinically evaluated using the Pedi-IKDC and Lysholm scores. In addition, return to sports and knee pain were assessed. MRI evaluation included an analysis of osteochondral graft integration using the magnetic resonance observation of cartilage repair tissue 2.0 score and radiographic classification of osteoarthritis using the Kellgren-Lawrence system. Nine patients (9 knees, 6 males) with a mean age of 14 years (SD: 1.7, range; 11 to 17y) were analyzed. Lesions were located on the medial facet (N=5), lateral facet (N=3), and central ridge of the patella (N=1). One or 2 cylindrical osteochondral grafts were transplanted, with a median diameter of 9mm (range: 8 to 10mm). The average lesion size was 102.9mm2. At a mean follow-up of 45.1 months (range: 23 to 117mo), the mean Pedi-IKDC score was 89.2 (SD: 9.8), and the Lysholm score was 94.4 (SD: 4.8). Patients returned to sports in an average of 7.3 months (SD: 2, range: 6 to 12mo). MRI of 8 patients showed osteochondral graft integration with a mean magnetic resonance observation of cartilage repair tissue 2.0 score of 86.9 (SD: 7, range: 80 to 100). Six knees showed Kellgren-Lawrence grade 0 joint space on radiographs, and 3 showed grade 1. Eight patients were asymptomatic at the last follow-up, and 1 reported occasional mild pain with intense physical activity. One patient developed arthrofibrosis, requiring arthroscopic lysis of adhesions and manipulation. Osteochondral autograft transplantation is a safe and effective technique for treating symptomatic patellar full-thickness chondral lesions in adolescents. Long-term follow-up studies will determine whether the affected area maintains structural and functional integrity over time. Level IV-therapeutic study.

Management of patellar and trochlear cartilage lesions with matrix-induced autologous chondrocyte implantation in conjunction with patellofemoral realignment procedures improves patient-reported outcomes and magnetic resonance image appearance

ObjectivesThe aim of this study is to evaluate the relationship between the achievement of clinically significant improvement in patient-reported outcome measures (PROMs) and the postoperative magnetic resonance image (MRI) appearance of matrix-associated chondrocyte implantation (MACI), in conjunction with patellofemoral realignment procedures, for the treatment of grade-IV chondral defects about the patellofemoral joint. MethodsA retrospective review of patients undergoing MACI for grade-IV chondral defects of the patella or trochlea by a single sports-medicine-fellowship-trained surgeon from 2017 to 2020 was performed. Concomitant realignment procedures, including tibial tubercle osteotomy and medial patellofemoral ligament reconstruction, were also performed as needed. Patients with preoperative and minimum 1-year postoperative PROMs and postoperative knee MRI were included. MRI scans were obtained at 6.3 (interquartile range: 5.8, 7.5) months postoperatively. A fellowship-trained musculoskeletal radiologist assigned a Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score (range: 0–100, with 100 equating to complete graft healing) to each MRI. Achievement of the minimal clinically important difference (MCID) for International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Score—Quality of Life, and Kujala scores were determined for each patient. Paired t-tests or Wilcoxon rank-sum tests were used to evaluate for an association between achievement of the MCID for each PROM and MOCART score. The average follow-up time and time from surgery to PROMs were 2.7 ​± ​1.5 years and 1.7 ​± ​0.66 years, respectively. ResultsThirty patients were included. There was a significant improvement in all PROMs from preoperative to postoperative (p ​< ​0.001). More than two-thirds of patients achieved the MCID for each PROM. Patients who achieved the MCID for IKDC had significantly higher MOCART scores (66.5 ​± ​16.2) than those who did not meet the MCID for IKDC (50.6 ​± ​23.6, p ​= ​0.043). ConclusionMACI for the treatment of patellofemoral chondral injuries is associated with clinically significant improvement in PROMs at short-term follow-up. Clinically significant improvements in IKDC scores are associated with a more mature MRI appearance of the autologous chondrocyte implantation graft on postoperative MRI, as indicated by higher MOCART scores. Level of evidenceIV—Case Series.

Poster 240: Radiographic and Patient-Reported Outcomes of Patellar Denovo Procedure in Shouldered Versus Unshouldered Patella Cartilage Lesions

Objectives: Unique challenges exist in treating patellar cartilage defects such as the contour of the articular surface and the high dynamic shear and compressive forces at the trochlear articulation. When considering restoration techniques osteochondral autograft or allograft can be used when the underlying bone is also involved but for isolated chondral defects, cell-based restoration is the standard of care. Previous literature has demonstrated that success of these cell-based therapies depends on a fully shouldered, stable rim of healthy cartilage to achieve repair stability. More recently, particulated juvenile articular cartilage (PJAC), minced hyaline cartilage from young donors, has demonstrated promising and practical results in the treatment of symptomatic articular defects of the patella and other surfaces. The newer cell-based techniques are more stable than previous options such as autologous chondrocyte implantation (ACI). The purpose of this study is to compare clinical outcomes of PJAC in patients with shouldered versus unshouldered full-thickness cartilage defects of the patella. We hypothesized that there will be no significant difference in short-term clinical outcomes and radiographic cartilage fill between shouldered and unshouldered lesions. Methods: A retrospective review of prospectively collected data was conducted on patients treated with PJAC for a full-thickness symptomatic patellar cartilage lesion between March 2014 and August 2019. Magnetic resonance imaging (MRI) was performed for all patients at 6, 12, and 24 months postoperatively and analyzed for percent fill, categorized by 0% to 33%, 34% to 66%, and 67% to 100% fill. Patient-reported outcome measures (PROMs) were obtained preoperatively and at 1, 2 and &gt;2 years postoperatively. Arthroscopic images were independently assessed, and cartilage defect characteristics were documented as shouldered or unshouldered by an orthopaedic surgery resident and an orthopaedic surgery sports fellow. Percent fill on MRI and clinical outcome scores (International Knee Documentation Committee, Kujala, Knee injury and Osteoarthritis Outcome Score – Physical Function Short-Form [KOOS-PS], Knee injury and Osteoarthritis Outcome Score – Quality of Life, The Hospital for Special Surgery Pediatric Functional Activity Brief Scale) were analyzed and correlated with the shouldered or unshouldered classification of the lesions. Results: Between March 2014 and August 2019, a total of 70 lesions in 65 patients were treated with PJAC for patellar cartilage lesions. The mean patient age was 26.6 years old (range, 14 – 51) and 76% (n = 53) were female. Twenty-five (36%) knees had undergone prior surgery and average symptom duration was 7.5 years. The average patellar lesion size was 277 mm2 (range, 77 – 800 mm2), the average number of allografts packets used was 2.4 (range, 1 – 5), and the average donor age was 46.1 months (range, 1 – 120). Arthroscopic pictures were available for 64 out of 70 lesions. There was perfect inter-rater reliability of whether the lesions were considered to have a continuous, stable rim (shouldered) or not (unshouldered). Thirty-two lesions were shouldered and the remaining 32 lesions were unshouldered according to their intraoperative pictures. Patients with shouldered lesions reported a significantly lower duration of symptoms than those with unshouldered lesions (5.29 ± 7.12 years vs.10.11 ± 9.85 years, p &lt; 0.05). Patients with shouldered lesions were also significantly more likely to have a prior knee surgery (p &lt; 0.05). Patients did not differ significantly by MRI percent fill in the shouldered versus unshouldered groups (Figure 1). There were no significant differences in baseline, 1-, or 2-year patient-reported outcomes based between patients with shouldered and unshouldered lesions (Table 1). The only statistically significant difference in outcomes was a lower score for KOOS-PS in the unshouldered group at &gt;2 years compared to the shouldered group (p &lt; 0.05), and in the change in KOOS-PS from baseline to 2-years between the 2 groups (p &lt;0.05). Conclusions: Patellofemoral joint cartilage defects are difficult to treat due to their unique thickness and topography. Historically, emphasis has been placed on having a stable, fully shouldered defect in order to achieve success of repair with microfracture or ACI. However, with the increased stability of newer cell-based treatments, these unshouldered cartilage lesions do well both clinically and radiographically. Our study found no significant differences between the shouldered and unshouldered groups with regard to both clinical outcomes as well as radiographic cartilage fill. This suggests that, with newer cartilage restoration techniques, whether a lesion is shouldered does not affect the outcomes achieved by these procedures. [Figure: see text]

Chitosan-based scaffold augmentation to microfractures: Stable results at mid-term follow-up in patients with patellar cartilage lesions.

Patellar cartilage lesions are a frequent and challenging finding in orthopaedic clinical practice. This study aimed to evaluate a chitosan-based scaffold's mid-term clinical and imaging results patients with patellar cartilage lesions. Thirteen patients (nine men, four women, 31.3 ± 12.7 years old) were clinically evaluated prospectively at baseline, 12, 24 and at a final minimum follow-up of 60 months (80.2 ± 14.7) with International Knee Documentation Committee (IKDC) subjective, Knee Injury and Osteoarthritis Outcome Score and Tegner scores. A magnetic resonance analysis was performed at the last follow-up using the Magnetic resonance Observation of CArtilage Repair Tissue (MOCART) 2.0 score. An overall significant clinical improvement in the scores was observed from baseline to all follow-ups, with stable clinical results from 24 months to the mid-term evaluation. The IKDC subjective score passed from 46.3 ± 20.0 at baseline to 70.1 ± 21.5 at the last follow-up (p = 0.029). Symptoms' duration before surgery negatively correlated with the clinical improvement from baseline to the final follow-up (p = 0.013) and sex influenced the improvement of activity level from the preoperative evaluation to the final follow-up, with better results in men (p = 0.049). In line with the clinical findings, positive results were documented in terms of cartilage repair quality with a mean MOCART 2.0 score of 72.4 ± 12.5. Overall, the use of this chitosan-based scaffold provided satisfactory results with a stable clinical improvement up to mid-term follow-up, which should be confirmed by further high-level studies to be considered a suitable surgical option to treat patients affected by patellar cartilage lesions. Level IV, prospective case series.

Outcomes of Particulated Juvenile Articular Cartilage and Association With Defect Fill in Patients With Full-Thickness Patellar Chondral Lesions.

Cartilage restoration procedures for patellar cartilage defects have produced inconsistent results, and optimal management remains controversial. Particulated juvenile articular cartilage (PJAC) allograft tissue is an increasingly utilized treatment option for chondral defects, with previous studies demonstrating favorable short-term outcomes for patellar chondral defects. To identify whether there is an association between defect fill on magnetic resonance imaging (MRI) with functional outcomes in patients with full-thickness patellar cartilage lesions treated with PJAC. Case series; Level of evidence, 4. A retrospective review of prospectively collected data was conducted on patients treated with PJAC for a full-thickness symptomatic patellar cartilage lesion between March 2014 and August 2019. MRI was performed for all patients at 6, 12, and 24 months postoperatively. Patient-reported outcome measures (PROMs) were obtained preoperatively and at 1, 2, and >2 years postoperatively. Clinical outcome scores-including the International Knee Documentation Committee (IKDC) score, the Kujala, the Knee injury and Osteoarthritis Outcome Score-Physical Function Short Form (KOOS-PS), the Knee Injury and Osteoarthritis Outcome Score-Quality of Life (KOOS-QoL), and the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS)-were analyzed and evaluated for a relationship with tissue fill on MRI. A total of 70 knees in 65 patients (mean age, 26.6 ± 8.1 years) were identified, of which 68 knees (97%) underwent a concomitant patellar stabilization or offloading procedure. Significant improvements were observed on all postoperative PROM scores at the 1-, 2-, and >2-year follow-up except for the Pedi-FABS, which showed no significant difference from baseline. From baseline to the 2-year follow-up, the KOOS-QoL improved from 24.7 to 62.1, the IKDC improved from 41.1 to 73.5, the KOOS-PS improved from 35.6 to 15, and the Kujala improved from 52 to 86.3. Imaging demonstrated no difference in the rate of cartilage defect fill between the 3-month (66%), 6-month (72%), 1-year (74%), and ≥2-year (69%) follow-ups. No association was observed between PROM scores and the percent fill of cartilage defect on MRI at the 1- and 2-year follow-up. PROM scores were significantly improved at the 2-year follow-up in patients who underwent PJAC for full-thickness patellar cartilage defects. On MRI, a cartilage defect fill of >66% was achieved by 3 months in most patients. In our sample, PROM scores were not significantly associated with the defect fill percentage at the short-term follow-up.

Osteochondral Allograft Transplant for Combined Medial and Lateral Patellar Cartilage Lesions: The Osteochondral Wide Lesion (OWL) Technique

Symptomatic articular cartilage injuries are often seen in young active patients and athletes. Magnetic resonance imaging screening examinations have frequently identified such lesions in athletic patients. Patellofemoral chondral defects were previously identified as the most common knee cartilage lesion in high-level athletes. Chondral defects measuring 2 cm2 or greater and complex cartilage defects involving bone loss are ideally replaced with fresh osteochondral allograft. We describe a technique indicated for patients with symptomatic and recurrent anterior knee pain associated with osteochondral patellar defects including the lateral and medial patellar facets. Patients who have undergone previous interventions, including membrane techniques, microfracture, or autologous chondral transplantation, without clinical benefit are also eligible to undergo osteochondral allograft transplantation for combined medial and lateral patellar cartilage lesions, that is, the osteochondral wide lesion (OWL) technique.

The SP-ET index is a new index for assessing the vertical position of patella

BackgroundSome parameters in previous studies did not better reflect the vertical position of the patella relative to the femoral trochlear. This study aimed to assess the value of the most superior point of patella-entrance of femoral trochlea distance ratio (SP-ET index) as a newer index in defining the vertical position of patella relative to the trochlea, correlate it with the Insall–Salvati ratio, and investigate the effect of the new index on patellar cartilage lesions.MethodsA total of 99 knees of 77 patients with patellar cartilage lesions were retrospectively analyzed using magnetic resonance imaging (MRI) data. The Insall–Salvati ratio and SP-ET index were measured on MR images. Ninety-nine knees just with meniscus rupture were enrolled as the control group. The two parameters of the patellar cartilage lesions were compared with those of the control group.ResultsThe Insall–Salvati ratio and SP-ET index in the patellar cartilage lesions group were significantly higher than those in the control group (p < 0.001). The SP-ET index showed a moderate positive correlation with the Insall–Salvati ratio (r = 0.307, p < 0.001). Receiver operating characteristic (ROC) analysis showed that the diagnostic efficiency of the SP-ET index was better than that of the Insall–Salvati ratio in patients with patellar cartilage lesions.ConclusionThe SP-ET index may be a useful complement parameter to define the vertical position of the patella relative to the femoral trochlear. Increased SP-ET index may be an important risk factor for patellar cartilage lesions.

Chitosan based scaffold applied in patellar cartilage lesions showed positive clinical and MRI results at minimum 2 years of follow up.

New scaffold-based cartilage regeneration techniques have been developed to improve the results of microfractures also in complex locations like the patello-femoral joint. The aim of this study was to analyse the results obtained in patellar lesions treated with a bioscaffold, a mixture composed by a chitosan solution, a buffer, and the patient's whole blood which forms a stable clot into the lesion. Fifteen patients with ICRS grade 3-4 cartilage lesions of the patellar surface were treated with a chitosan bioscaffold. Fourteen patients were clinically and radiologically evaluated prospectively for a minimum follow-up of 2years with IKDC, KOOS, Tegner score, and MRI.The mean age of patients at the time of surgery was31.8 ± 11.9and nine patients presented degenerative aetiology, four patients with previous trauma, and 1 patient with osteochondritis dissecans. RESULTS: The IKDC subjective score improved from 46.2 ± 19.3 preoperatively to 69.5 ± 20.3 (p < 0.05) and74.1 ± 23.2(p < 0.05) at 12 and 24months, respectively. Also KOOS Pain, KOOS Sport/Rec and KOOS QOLshowed a significant improvement from baseline to 12months and to the final follow-up.MRI evaluation showed a complete filling of the cartilage defect at the final follow-up in 70% of the lesions, obtaining a total MOCART 2.0 score of 71.5 ± 13.6 at 24months after surgery. Chondral patellar lesions represent a complex pathology, with lower results compared to other sites. This bioscaffold representsa safe surgical treatment providing a significant clinical improvement at 24months in the treatment of patellar cartilage lesions. IV.

THE RELATIONSHIP BETWEEN LOWER LIMB MUSCLE STRENGTH AND PATELLAR CARTILAGE VOLUME IN SENIOR COMMUNITY ADULTS

Purpose: Osteoarthritis is one of the leading causes to disability in the older population around the world. Patellofemoral osteoarthritis (PFOA) featured by patellar cartilage lesion is highly prevalent in this population. Lower limb muscle strength weakness is widely believed to be a biomechanical risk factor to the development of PFOA. However, there lacked evidence about how these muscle weakness and patellar cartilage lesion linked with each other. This study aimed to explore the relationship between quadriceps, hip abductor muscle strength and patellar cartilage volume in senior community adults.

Clinical and Radiographic Outcomes After Treatment of Patellar Chondral Defects: A Systematic Review

There is currently no evidence-based consensus on how to treat a full-thickness, symptomatic articular cartilage injury of the patella, although numerous treatment options are available. To systematically evaluate the functional outcomes after operative treatment of patellar cartilage lesions. Our secondary purpose was to evaluate radiographic outcomes after treatment. PubMed, Cochrane, and Embase. Studies published between January 1, 1990 and December 31, 2018 that included patient-reported functional outcomes for patients after operative treatment of patellar chondral defects at a minimum 2-year follow-up were included. Systematic review. Level 4. MINORS (Methodological Index for Non-Randomized Studies) score, level of evidence, sample size, demographic data, follow-up data, intervention, functional outcome scores, and magnetic resonance imaging (MRI) data were collected. The review identified 10 studies and 293 patients receiving cartilage restoration procedures for patellar chondral defects with extractable clinical and radiographic results and data on complications and reoperations. All treatments (autologous chondrocyte implantation [ACI], matrix-induced ACI [MACI], autologous osteochondral transplantation [AOT]) utilized in the management of patellar chondral lesions, with the exception of isolated particulated juvenile articular cartilage, demonstrated statistically significant improvements in functional outcome scores compared with preoperative measurements at a minimum of 2-year follow-up. Postoperative MRIs were obtained in 6 studies and found that regardless of treatment, moderate-to-complete infill of patellar cartilage lesions was seen in the majority of patients. While failure rates were low for the various treatment modalities, rates of reoperation were substantial, with up to 40% to 60% reoperation rate seen after ACI. Patients treated with ACI, MACI, and AOT all demonstrated statistically significant improvements in functional outcome scores with radiographic evidence of healing at minimum of 2-year follow-up. Evidence is insufficient to recommend one particular treatment over another.

High tibial derotation osteotomy for distal extensor mechanism alignment in patients with squinting patella due to increased external tibial torsion

BackgroundThe patellofemoral joint is often affected by torsionaldisorders of the lower limb, causing pain, instability and knee degeneration. The aims of this study were to determine functional outcomes of patients who underwent a high tibial derotation osteotomy (HTDO) for symptomatic squinting patella due to increased external tibial torsion. Moreover, factors associated with inferior clinical outcomes were investigated. MethodsPatients with symptomatic squinting patella, increased external tibial torsion (>30°) treated with this technique, and with 2 years of follow up were included. Fulkerson and Kujala patellofemoral joint scores were assessed. Age, body mass index, history of prior surgery, increased femoral anteversion, association of lateral retinaculum release and patellar cartilage lesions were analysed. ResultsSixty HTDOs were included in this retrospective study with an average of 66 months of follow up. The mean Kujala score improved from 47.5 preoperatively to 93 postoperatively. The mean Fulkerson score improved from 40.6 to 91.6. Kujala subscores for pain improved from 8.6 to 30.4, for instability improved from 6.4 to 17.9, and their ability to climb stairs increased from 6.9 to 17.9 (all P < 0.0001). Multivariate logistic regression model identified that patient age (P < 0.005) and advanced chondral damage (P < 0.001) were the dominant factors predicting inferior clinical outcomes using Kujala’s score. ConclusionHTDO provided good results regarding the pain symptoms, instability and the ability to climb stairs. Advanced chondral damage and advanced age had negative effects on outcomes.

The Sagittal Tibial Tubercle-Trochlear Groove Distance as a Measurement of Sagittal Imbalance in Patients with Symptomatic Patellofemoral Chondral Lesions.

Objective. To measure the sagittal alignment of the tibial tubercle through the sagittal tibial tubercle-trochlear groove (sTTTG) distance in patients with and without patellar chondral lesions. Design. Patients treated with patellofemoral cartilage restoration or repair procedures were retrospectively reviewed (group 1; N = 17). A control group of patients (group 2; N = 20) undergoing partial meniscectomy with normal patellar cartilage was included. An asymptomatic patellar chondrosis group (group 3; N = 15) was identified as patients undergoing partial meniscectomy with patellar cartilage wear. The sTTTG was measured on the preoperative axial T2 magnetic resonance imaging (MRI) sequence. The first point was the nadir of the anterior trochlear cartilage, and the second point was the anterior tibial tubercle. A line was drawn between these points, perpendicular to the posterior condylar axis. Comparisons were made between the 3 groups using analysis of variance testing with Bonferroni corrections. Significance was defined as P < 0.05. Results. The mean sTTTG was significantly more posterior in group 1 (5.9 ± 5.5 mm posterior to the trochlear groove) relative to group 2 (0.8 ± 5.3 mm posterior; P = 0.018). The mean value for group 3 (2.7 ± 5.3 mm posterior) fell between group 1 and 3 but was not significantly different from group 1 (P = 0.31) or group 2 (P = 0.89). There were no significant differences with regards to sulcus angle, Caton-Deschamps Index, TTTG, or knee flexion angle on the MRI scan. Conclusions. A more posteriorly positioned tibial tubercle was observed in patients with patellar cartilage lesions relative to those with intact patellar cartilage. Intermediate positioning was observed in patients with asymptomatic patellar chondral wear. Level of Evidence. Level 3 diagnostic study.

Chondromalacia Patella among Military Recruits with Anterior Knee Pain: Prevalence and Association with Patellofemoral Malalignment.

Background:The aim of this study was to investigate the frequency of chondromalacia patella (CMP) and to evaluate its relation with trochlear morphometric and patellofemoral alignment measurements as well as with edema in superolateral region of Hoffa's fat pad (SHFP) in military recruits with anterior knee pain (AKP).Materials and Methods:Knee magnetic resonance imaging examinations of 288 military recruits with AKP were retrospectively evaluated. Patellar cartilage lesions were graded using modified Noyes system. Quantitative measurements of trochlear morphology (sulcus angle, trochlear sulcus depth, and lateral trochlear inclination [LTI]) and patellofemoral alignment (patellar translation [PT], lateral patellofemoral angle (LPA), Insall-Salvati index, and tibial tuberosity-trochlear groove distance) were made. The SHFP region was assessed for the presence of edema. Mean values of measurements in knees with and without CMP and in knees with early and advanced stage CMP were compared.Results:We found CMP in 169 (58.7%) patients. Patients with CMP demonstrated a significantly greater sulcus angle (P = 0.012), smaller LTI (P = 0.004), greater PT (P = 0.01), smaller LPA (P = 0.036), greater Insall-Salvati ratio (P = 0.034), and higher incidence of SHFP edema (P = 0.001) compared to those without CMP. While none of the measurements were associated with the severity of cartilage damage, the incidence of SHFP edema was significantly correlated with the severity of CMP (P = 0.001).Conclusion:CMP is a common disorder among military recruits with AKP. Patellofemoral malalignment is an important contributory factor in the development of CMP, and the presence of edema in SHFP may be a strong indicator of underlying severe CMP in this population.

Potential predictive value of axial T2 mapping at 3 Tesla MRI in patients with untreated patellar cartilage defects over a mean follow-up of four years

The objective was to demonstrate the potential of axial T2 mapping for quantification of untreated early-stage patellar cartilage lesions over time and to assess its capability as a potential predictive marker for future progression. Thirty patients (mean age, 36.7±11.1 years; 16 males), with early-stage patellar cartilage defects (≤ICRS grade 2) at baseline and no treatment during follow up (4.0±1.6 years) were enrolled. Morphological cartilage changes over time were subdivided into a Progression, Non-Progression Group and Regression Group. Quantitative analysis of cartilage defects and healthy reference was performed by means of global and zonal T2 mapping (deep and superficial cartilage T2 values) at both time points. Statistical evaluation included analysis of variance (ANOVA), paired t Test's and ROC analysis. The Progression Group (N=11) had significantly higher global T2 values at baseline (57.4±7.8ms) than patients without (N=17) (40.6±6.9ms) (P<0.01). Furthermore the Non-Progression Group showed only a minor increase in global T2 relaxation times to 43.1±7.9ms (P=0.07) at follow up, whereas in the progression group global (68,7±19ms: P=0.02) and superficial T2 values (65,8±8.2-79.8±24.4ms; P=0.03) increased significantly. T2 values for healthy reference cartilage remained stable. In 2 patients an improvement in ICRS grading was observed (Regression Group) with decreasing T2 values. The ROC analysis showed an area under the curve of 0.92 (95%CI 0.82-1.0). At a cut-off value of 47.15ms, we found a sensitivity of 92% (false-positive rate of 18%) for future progression of cartilage defects. This study provides evidence regarding the possible potential of axial T2 mapping as a tool for quantification and prediction of patellar cartilage defect progression in untreated defects.

Arthroscopic Treatment of Patellar and Trochlear Cartilage Lesions with Matrix Encapsulated Chondrocyte Implantation versus Microfracture: Quantitative Assessment with MRI T2-Mapping and MOCART at 4-Year Follow-up.

Seventeen patients aged 18 to 55 years with symptomatic full-thickness cartilage lesions on either patella or trochlea were treated with matrix autologous chondrocyte implantation (MACI) or microfracture (MF). Both procedures combined with unloading/realigning techniques. Clinical assessment and T2-mapping were evaluated at 48-months. Clinically results from pre-op to 48-months improved significantly in MACI and MF for Lysholm (p = 0.001, p = 0.001), IKDC-S (p = 0.001, p = 0.002), KOOS-P (p = 0.000, p = 0.002), KOOS-DLA (p = 0.002, p = 0.003), KOOS-Sports/Rec (p = 0.000, p = 0.004), KOOS-QoL (p = 0.000, p = 0.003), KOOS-symptoms (p = 0.001, p = 0.020), and Kujala (p = 0.000, p = 0.01), respectively. Tegner was significant between baseline and 48 months only for MACI (p < 0.008) compared with MF (p = 0.25). No significant difference was observed between groups for any score at 3, 12, 24, and 48-months (p > 0.05). T2-mapping values improved significantly over time in MACI compared with MF at 24 months (39.35 vs. 50.44, p = 0.007) and 48 months (36.54 vs. 48.37, p = 0.005). When comparing control values to MACI at 12-m (p = 0.714), 24-m (p = 0.175), and 48-m (p = 0.097), no significant difference was found. MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score comparison gave no statistical difference between groups. Clinically both techniques improved significantly over time. However, quantitative assessment showed that only newly formed tissue with MACI technique improves significantly since 12-months and maintains stable values compared with native cartilage until 48-month follow-up. MF results were never comparable to those native values. Level of evidence II.

Clinical mid- to long-term outcome after autologous chondrocyte implantation for patellar cartilage lesions and its correlation with the geometry of the femoral trochlea

BackgroundThe aim was to investigate the clinical results after autologous chondrocyte implantation (ACI) at the patella in a mid- to long-term course, and whether trochlear dysplasia has an influence on the outcome. MethodsInclusion criteria were ACI for focal patella cartilage defects and preoperative magnetic resonance imaging (MRI). Patients with previous trochleoplasty or osteotomy have been excluded. Trochlea morphology was evaluated by sulcus depth, sulcus angle, lateral condyle index (LCI) and Dejour's classification for trochlea dysplasia. The clinical outcome was evaluated by a questionnaire including the Kujala- and IKDC-Scores. Survival of the ACI was analysed by the Kaplan–Meier method. A correlation analysis between morphologic parameters and clinical scores was performed. ResultsSeventy-eight patients (mean age 33.2 ± 10.7 years) were included (mean follow-up 6.5 ± 3.4 years). The mean sulcus depth was 5.0 ± 1.6 mm (normal value ≥5 mm), the mean sulcus angle was 153.4 ± 9.0° (normal value ≤145°) and the mean LCI was 84.9 ± 7.5% (normal value ≥90%). Major trochlea dysplasia (grades B–D) was seen in 29 patients (36.7%). Five-year survival rate was 98%, satisfaction-rate was 78.9% and the mean clinical scores were 67.6 ± 20.2 for the Kujala-Score and 64.7 ± 20.2 for the IKDC-Score. A lower LCI showed significant correlation with a lower IKDC score (r = 0.25; p = 0.037). ConclusionsThe present study reports an excellent survival rate and a good satisfaction rate in a mid- to long-term course after patella ACI. The clinical scores show a high variance and there is evidence that a pathologic trochlea correlates with inferior results.

Autologous Osteochondral Transplantation in Full-thickness Patella Chondral Lesion: A Case Series.

Purpose:Autologous osteochondral transplantation (AOT) in the focal cartilage lesion of the patella has been reported with less successful results compared with other sites. The purposes were to investigate the clinical outcomes of AOT for focal patellar chondral lesion without patellofemoral instability.Methods:Between 2001 and 2007, six patients (five males and one female) with a focal patellar cartilage lesion without patellofemoral malalignment and instability were treated with AOT. The mean age was 38 (27–51) years. Intraoperatively, the size and location of lesion were assessed by international cartilage repair society classification. Lysholm score was investigated preoperatively, at 6 months, 1- and 2-year, and final follow-up. Mean follow-up period was 51 months (24–101). Transplanted grafts were evaluated by magnetic resonance imaging (MRI) and second-look arthroscopy.Results:The mean size was 133mm2(78–225). All six cases improved at final follow-up (Lysholm score 79–100). Although immediate pain relief obtained in four cases, severe pain was persistent in remaining two cases during the 1styear and gradually relieved by 2 years following surgery. The size of these two cases was significantly larger (over 170 mm2) than that of four cases (100 mm2 in average) (P<0.05), and their locations were apart from center of the patella inspite of four cases localized centrally (P<0.05). Repaired cartilage did not show any difference by MRI and arthroscopically.Conclusion:AOT in focal patellar chondral lesions without patellofemoral malalignment showed excellent results. In cases of large off-centeredlesions, however, it took longer for pain relief following AOT.

Open Implantation of Autologous Chondrocytes Cultured on Porcine Collagen Membrane for the Treatment of a Full-Thickness Patellar Cartilage Lesion.

Large cartilage defects in the knee are debilitating for patients and challenging for surgeons to treat. Autologous chondrocyte implantation (ACI) has gained popularity over the past 20 years and has become the treatment of choice for large cartilage defects for some surgeons. Termed matrix-applied ACI (MACI), use of autologous chondrocytes cultured on porcine collagen membrane has recently been approved by the U.S. Food and Drug Administration for the treatment of symptomatic full-thickness cartilage defects in the knee. This new technique for cartilage repair is the third generation of chondrocyte implantation technology and the first to involve the use of a scaffolding to grow chondrocytes1. MACI is a simpler technique than previous generations and has more reliable chondrocyte seeding. Research has shown that patients do well postoperatively, with improvements in patient-reported outcome out to 5 years postoperatively3. These improvements are statistically greater for patients who underwent MACI when compared to those who underwent microfracture2. (1) Preoperative evaluation: patients are indicated for a cartilage procedure after magnetic resonance imaging (MRI) and clinical examination. (2) Stage 1: a diagnostic arthroscopy is performed, and chondrocytes are harvested and cultured. (3) Approach: a short vertical incision is made, followed by a medial parapatellar arthrotomy. (4) Debridement: the lesion is identified and debrided back to stable cartilage. (5): Hemostasis: hemostasis is obtained with an epinephrine-soaked sponge. (6) Template creation: foil is used to create a template of the lesion. (7) Cells cutting: with use of the foil, the membrane of cells is cut to the appropriate size and shape. (8) Implantation: the cut membrane is placed on the lesion and secured with fibrin glue. (9) Testing: the knee is taken through a range of motion and the stability of the membrane is confirmed. (10) Closure: standard closure in layers is performed.

3D convolutional neural networks for detection and severity staging of meniscus and PFJ cartilage morphological degenerative changes in osteoarthritis and anterior cruciate ligament subjects.

Semiquantitative assessment of MRI plays a central role in musculoskeletal research; however, in the clinical setting MRI reports often tend to be subjective and qualitative. Grading schemes utilized in research are not used because they are extraordinarily time-consuming and unfeasible in clinical practice. To evaluate the ability of deep-learning models to detect and stage severity of meniscus and patellofemoral cartilage lesions in osteoarthritis and anterior cruciate ligament (ACL) subjects. Retrospective study aimed to evaluate a technical development. In all, 1478 MRI studies, including subjects at various stages of osteoarthritis and after ACL injury and reconstruction. 3T MRI, 3D FSE CUBE. Automatic segmentation of cartilage and meniscus using 2D U-Net, automatic detection, and severity staging of meniscus and cartilage lesion with a 3D convolutional neural network (3D-CNN). Receiver operating characteristic (ROC) curve, specificity and sensitivity, and class accuracy. Sensitivity of 89.81% and specificity of 81.98% for meniscus lesion detection and sensitivity of 80.0% and specificity of 80.27% for cartilage were achieved. The best performances for staging lesion severity were obtained by including demographics factors, achieving accuracies of 80.74%, 78.02%, and 75.00% for normal, small, and complex large lesions, respectively. In this study we provide a proof of concept of a fully automated deep-learning pipeline that can identify the presence of meniscal and patellar cartilage lesions. This pipeline has also shown potential in making more in-depth examinations of lesion subjects for multiclass prediction and severity staging. 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:400-410.

All-Arthroscopic Autologous Matrix-Induced Chondrogenesis-Aided Repair of a Patellar Cartilage Defect Using Dry Arthroscopy and a Retraction System.

The technique of all-arthroscopic autologous matrix-induced chondrogenesis (AMIC)-aided repair of patellar cartilage lesions using a retraction system and dry arthroscopy has been recently described. We report the first clinical and radiological data at a short-term follow-up. Twelve patients underwent AMIC-aided cartilage repair for a patellar lesion. All steps of the procedure were performed arthroscopically, which include the use of an intra-articularly placed retraction plate for distraction of the patellofemoral joint and evacuation of saline solution for collagen matrix insertion and fixation. Clinical assessment performed before surgery and at a mean follow-up time of 38 months (range: 24-70) included the following scores: Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC), and visual analog scale (VAS). Magnetic resonance imaging was performed at the follow-up examination, including the magnetic resonance observation of cartilage repair tissue (MOCART) score. The mean KOOS and IKDC scores increased significantly (p < 0.01) from 50.3 and 37.4 points preoperatively to 90.1 and 79.4 postoperatively. The VAS score decreased from 7.8 to 2.3 points. Mean MOCART score at follow-up was 58.3 points. Cartilage repair of patellar lesions aided by a retraction system in a dry arthroscopy setup is a promising approach. Further studies are needed to evaluate this procedure and compare it to existing matrix implantation techniques. The level of evidence for the study is 4 (case series).