Retropatellar Cartilage Research Articles

Refixation of osteochondral flake fractures after patellar dislocation-The parachute technique

Patellar dislocations are acommon occurrence in orthopedic practice, often accompanied by osteochondral fractures of the retropatellar cartilage surface, known as flake fractures, in up to 58% of cases. The parachute technique represents asimple and cost-effective surgical option aimed at restoring osteochondral integration and preserving native cartilage. Flake fracture of the patella with osteochondral fragments. Patella fracture. By utilizing transpatellar, absorbable sutures, astable osteochondral interface is achieved without penetrating the fragment itself. Postoperative treatment involves partial weight-bearing with amaximum of 20 kg for 6weeks in full knee extension. In addition, the range of motion of knee flexion is limited to30° and is increased by30° every 2weeks. To examine the short- to medium-term clinical outcomes, all patients with acute patellar dislocation treated using the parachute technique between 01/2012 and 11/2022 were included. Clinical outcomes were assessed using the visual analog scale (VAS), Tegner Activity Scale (TAS), Kujala Score, Knee Injury and Osteoarthritis Outcome Score (KOOS), and International Knee Documentation Committee (IKDC). Out of 20patients, 19 (10men, 11right-sided, 95% follow-up rate) could be recruited for postoperative evaluation. The average follow-up period was 62.5 ± 20.5 months. The clinical outcome scores yielded the following results: VAS 0.5 ± 1.6, TAS 5.8 ± 2.2, Kujala 89.4 ± 12.5, KOOS 87.8 ± 14.1, and IKDC 86.7 ± 14.3. Overall, 18patients (90.0%) expressed willingness to undergo the procedure again. At the time of follow-up, 19patients (95.0%) were satisfied with the surgical outcome. One patient (23-year-old man) required revision. None of the included patients suffered from the recurrence of patellar dislocation. In summary, the parachute technique demonstrated excellent clinical function in the short- to medium-term follow-up for acute patellar dislocation.

The Synovial Sealant Variant for Minced Cartilage Repair: A Technical Note and Retrospective Study

PurposeCartilage defects are a common pathology in active people and affect quality of life. A common treatment option is treatment with minced cartilage (MC). As conservative therapy has a limited effect, surgical treatments vary in terms of procedure and results. A modified technique for autologous cartilage repair is presented here.MethodMC was modified by adding a synovial sealant. This improves the stability of the graft, allowing the cartilage to proliferate. The synovial tissue has the potential to stimulate the implanted cartilage, which promotes healing and regeneration. The clinical and functional results of the modified technique were examined in a retrospective case series.ResultsThe technique has proven to be reproducible for retropatellar cartilage defects and is both efficient and cost effective. MC with synovial sealing was performed in ten patients with retropatellar cartilage damage. In the conducted cases serious, 10 patients were available for follow-up after 18 ± 3 months. Patients showed good clinical results in terms of pain (VAS = 1.9, KOOS Pain = 89.7), symptoms (KOOS Symptoms = 83.6), and daily activity (KOOS Activity = 96.6).ConclusionThe procedure combines the advantages of autologous cartilage repair with a one-stage surgical approach. It utilizes the regenerative potential of synovial tissue while providing improved mechanical stability. This technique offers a cost-effective, autologous solution for full-thickness cartilage defects, and shows promising clinical results in the medium term.

Comparison of Different Methods of Semiquantitative Assessment and Subjective Scores for Retropatellar Articular Cartilage Evaluation in Advancing Osteoarthritis.

cartilage layer thickness, composition of the extracellular matrix (ECM), geometry and configuration of retropatellar cartilage partially differ significantly from those found at other locations and are essential for patellofemoral biomechanics. 119 serial medial and lateral patella facet samples of patients undergoing implantation of a total knee endoprosthesis of areas showing mild (Group A, macroscopically ICRS Grade 1b) respectively advanced (Group B, macroscopically ICRS Grade 3a/3b) (38 each) osteoarthritis according to the histological-histochemical grading system (HHGS) were compared with 22 healthy biopsies by means of immunohistochemistry and histology investigations. We quantified our results on the gene expression of collagen type I and II and aggrecan with real-time (RT)-PCR rsp using colourimetry for proteoglycan content. The digitized images of histology and immunohistochemistry staining with Safranin O, Alcian blue, PAS, Masson Goldner, immunostaining, e.g. for collagen I and II were also analyzed with Photoshop software. The most significant decrease in staining intensity was revealed for Safranin-O staining in Group B at the lateral patellar facet, and the most relevant increase was for Col I staining at the same site. The lateral patella site in Group B also showed the highest increase in the ratio of expression indices for the genes Col1A1 and the reference gene following the equation 2-ΔCt with a quotient of 29.6. 1. Comparisons of our retropatellar cartilage analysis with femoral and tibial studies utilizing similar techniques show significant differences. 2. Cartilage layer thickness, ECM composition, geometry and configuration are essential for patellofemoral biomechanics. 3. Consequently, there is a need for diversified approaches towards retropatellar surface during TKA as well as for advanced cartilage restoration techniques.

Positive outcomes following Autologous Matrix-Induced Chondrogenesis (AMIC) in the treatment of retropatellar chondral lesions: a retrospective analysis of a patient registry

BackgroundThe patellofemoral joint is a challenging environment for treating chondral defects. Among the surgical options for the treatment of chondral defects, the single-stage Autologous Matrix-Induced Chondrogenesis (AMIC) procedure uses a porcine collagen I/III membrane to enhance bone-marrow stimulation. However, longer term outcomes data are rare for this specific indication. In order to provide real-world information, an ongoing registry has been established to record patient data and outcomes when AMIC is used to treat chondral and osteochondral lesions.MethodsPatient data were retrieved from an ongoing, prospective, multisite registry of patients who had undergone AMIC treatment of chondral defects. We identified 64 patients who had undergone AMIC for patellofemoral chondral defects and for whom pre-operative and at least 1 post-operative score were available were included in this retrospective data analysis. Outcomes were assessed via the KOOS, VAS pain, and the Lysholm scores. Outcomes at the post-operative time-points were analysed using a factorial ANOVA with post-hoc testing while linear regression was used to assess associations between the change in the Lysholm score and lesion size.ResultsThere was a significant improvement in Lysholm, VAS pain, and KOOS scores from pre-operative to the 1st year post-operative (p < 0.001), and this was maintained during the follow-up.ConclusionsThe forces exerted on the patellofemoral joint make this a challenging scenario for chondral repair. Our data demonstrates that the AMIC procedure with a collagen I/III membrane is an effective treatment for retropatellar cartilage lesions, and provides reliable results, with decreased pain and improved function. Importantly, these improvements were maintained through the follow-up period.

Deep Learning Convolutional Neural Network Reconstruction and Radial k-Space Acquisition MR Technique for Enhanced Detection of Retropatellar Cartilage Lesions of the Knee Joint.

To assess diagnostic performance of standard radial k-space (PROPELLER) MRI sequences and compare with accelerated acquisitions combined with a deep learning-based convolutional neural network (DL-CNN) reconstruction for evaluation of the knee joint. Thirty-five patients undergoing MR imaging of the knee at 1.5 T were prospectively included. Two readers evaluated image quality and diagnostic confidence of standard and DL-CNN accelerated PROPELLER MR sequences using a four-point Likert scale. Pathological findings of bone, cartilage, cruciate and collateral ligaments, menisci, and joint space were analyzed. Inter-reader agreement (IRA) for image quality and diagnostic confidence was assessed using intraclass coefficients (ICC). Cohen's Kappa method was used for evaluation of IRA and consensus between sequences in assessing different structures. In addition, image quality was quantitatively evaluated by signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) measurements. Mean acquisition time of standard vs. DL-CNN sequences was 10 min 3 s vs. 4 min 45 s. DL-CNN sequences showed significantly superior image quality and diagnostic confidence compared to standard MR sequences. There was moderate and good IRA for assessment of image quality in standard and DL-CNN sequences with ICC of 0.524 and 0.830, respectively. Pathological findings of the knee joint could be equally well detected in both sequences (κ-value of 0.8). Retropatellar cartilage could be significantly better assessed on DL-CNN sequences. SNR and CNR was significantly higher for DL-CNN sequences (both p < 0.05). In MR imaging of the knee, DL-CNN sequences showed significantly higher image quality and diagnostic confidence compared to standard PROPELLER sequences, while reducing acquisition time substantially. Both sequences perform comparably in the detection of knee-joint pathologies, while DL-CNN sequences are superior for evaluation of retropatellar cartilage lesions.

Long-term effects of retrograde approach on the knee after motorized femoral limb lengthening.

The retrograde femoral approach is an established technique for implantation of nails for leg lengthening and correction and in cases of distal femoral fractures. The purpose of this study was to determine the 10-year outcome of this technique by analyzing the clinical long-term effects and radiological status of the knee after leg lengthening via a retrograde femoral approach. This retrospective single-center study included 13 patients (median age at surgery 17 [range 15-20] years) who underwent unilateral, retrograde, femoral lengthening with a motorized nail. Outcome measurements were graded variables of the SF-36, ISKD score, and Lysholm score. MRI of both knees was performed in all patients. MRI was evaluated for the presence of degenerative changes and compared with the healthy contralateral knee. Cartilage condition was graded according to the International Cartilage Repair Society (ICRS) scoring system. All patients were pain-free and had a full range of motion 10 (range 10.0-12.2) years after surgery. All postoperative knees showed fibrosis of Hoffa's fat pad and moderate to severe cartilage defects (ICRS Grade 2-4) of the trochlear groove (nail entry site). 6 out of 13 operated knees exhibited retropatellar cartilage defects. Our study showed that patients were pain-free, but cartilage defects at the entry point and arthrofibrosis at Hoffa's fat pad were observed without causing clinical impairment.

The Conformity of Rehabilitation Protocols Used for Different Cartilage Repairs of the Knee Joint—A Review on Rehabilitation Standards in German Speaking Countries

The present study analysed current rehabilitation protocols to investigate whether there is a standard for early rehabilitation after microfracturing (MFX), matrix-assisted cartilage transplantation (MACT), and osteochondral autograft transfer (OATS) of the knee joint in clinical routine, and if rehabilitation protocols differ in the repair technique used or the localization of the cartilage defect. The evaluation included rehabilitation criteria such as weight-bearing, range of motion, use of an orthosis, motion therapy, and rehabilitation training during the early rehabilitation phase after MFX, MACT, and OATS of the femorotibial and retropatellar joint space. We analysed 153 rehabilitation protocols after cartilage repair of the knee joint, including 137 protocols for after repair of the main weight-bearing (femorotibial) area and 16 for after retropatellar cartilage repair. Most of the protocols differed significantly according to the location of the repair and the procedure performed. Our findings indicate that full weight-bearing can be achieved significantly faster after MFX (5.6 weeks) and OATS (5.3 weeks) than after MACT of the main weight-bearing zone (6.6 weeks, p &lt; 0.001). In addition, after retropatellar cartilage repair, patients are allowed full weight-bearing after 2.1 weeks compared to the main weight-bearing zone (5.3–6.6 weeks; p &lt; 0.001). No standardized rehabilitation recommendations have been established. The present study shows that rehabilitation needs to be adjusted to the surgical technique and the location of the defect zone, and further investigation is warranted to establish standardized rehabilitation protocols after cartilage repair of the knee joint.

Autologous Matrix-Induced Chondrogenesis (AMIC) for Isolated Retropatellar Cartilage Lesions: Outcome after a Follow-Up of Minimum 2 Years.

PurposeTo evaluate autologous matrix-induced chondrogenesis (AMIC) for isolated focal retropatellar cartilage lesions and the influence of patellofemoral (PF) anatomy on clinical outcomes at a minimum of 2-year follow-up.MethodsTwenty-nine consecutive patients (31 knees) who underwent retropatellar AMIC with a mean age of 27.9 ± 11.0 years were evaluated at a follow-up averaging 4.1 ± 1.9 years (range, 2-8 years). Patient factors, lesion morphology, and patient-reported outcome measures, including Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner, Kujula score, and visual analogue scale (VAS) score were collected. PF anatomy was assessed on pre- and postoperative imaging, and subsequently correlated to outcome scores and failure to determine risk factors for poor outcome.ResultsAt final follow-up, the AMIC graft failed in 4 cases (12.9%) at a mean follow-up of 21 ± 14.1 months. Patients with failed grafts had a significantly smaller patellar and Laurins’s PF angle than patients whose graft did not fail (P = 0.008 and P = 0.004, respectively). Concomitant corrective surgery for patellar instability was performed in 29 knees (93.5%). Grafts that did not fail presented with an average Kujala score of 71.3 ± 16.9, KOOS Pain of 76.2 ± 16.6 and Tegner scores of 4.2 ± 1.8. The patellar angle was significantly associated with the patient’s satisfaction level (r = 0.615; P < 0.001).ConclusionAMIC for retropatellar cartilage lesions in combination with concomitant corrective surgery for patellar instability results in low failure rate with satisfactory clinical outcome and patient satisfaction of almost 80% at mid-term follow-up. As most failures occurred in patients without concurrent tibial tubercle osteotomy and both a smaller patellar and Laurins’s PF angle were associated with less favorable outcome, this study supports the growing evidence for the need of unloading retropatellar cartilage repair, when indicated.Level of EvidenceCase series; level of evidence, 4.

Prone-positioned knee arthroscopy for isolated retropatellar cartilage defects with gel-type autologous chondrocyte implantation.

Treatment of isolated retropatellar cartilage defects using current gel-type regenerative methods requires settlement of the gel to the underlying subchondral bone under gravity; thus, prone positioned arthroscopy is used. Isolated retropatellar contained cartilage defect size >2.5 cm2. Age <40years, epiphyseal closure, cartilage defect grade3/4 (International Cartilage Repair Society). Cartilage defects at medial or lateral femorotibial compartments, at the trochlea, with degenerative genesis, rheumatoid arthritis, local infection, patellar malalignment, patellofemoral dysplasia, knee instability, knee malalignment >3°, kissing lesions. Two-stage procedure: At initial arthroscopy, chondrocytes were harvested. At the second stage, the patient was positioned prone and the leg with athigh tourniquet was fixed in aleg holder. Removal of table extension below the knee and support of foot in sling to prevent knee hyperextension. Placement of 2lateral portals. Lesion visualized and debrided, followed by aspiration of intra-articular fluid. Aloop, placed posterior to the patellar ligament using alasso, was used to suspend aweight to expand the patellofemoral space. The lesion was then dried using asponge. NOVOCART® Inject (TETEC, Reutlingen, Germany) administered onto the defect. Gel was allowed to solidify for15 min and operation was completed. Knee locked in extension using abrace for 6weeks. Continuous passive motion applied and incrementally increased until full range of motion (ROM) at week6. Weight-bearing as tolerated was allowed with the knee in extension. Routine clinical follow-up after 3, 6 and 12months. Mean age of the 5patients was 23 ± 6 (range 14-30) years; mean follow-up time after surgery 28 ± 7 (range 20-40) months. All patients returned to full activity without residual knee ROM restriction. Clinical examination at the latest follow-up revealed aKujala score of 90 ± 12 points and Lysholm score of 95 ± 5 points. MRI showed filled cartilage defects in all patients. Mocart score was 63 ± 7 points. Cartilage was inhomogeneous and hyperintense at the repaired site. Quantitative measurement of the patella mobility of the operated knee under atranslating force of 10 N showed medial and lateral displacements of 21 ± 5 and 15 ± 2 mm and on the healthy side 22 ± 5 and 19 ± 3 mm, respectively.

Good healing potential of patellar chondral defects after all-arthroscopic autologous chondrocyte implantation with spheroids: a second-look arthroscopic assessment.

To report second-look arthroscopic assessment after all-arthroscopic autologous chondrocyte implantation (ACI) for articular cartilage defects at the patella. A second-look arthroscopy after all-arthroscopic ACI using chondrospheres® (ACT3D) was performed in 30 patients with 30 full-thickness retropatellar cartilage defects. The mean time from ACI to second-look arthroscopy was 14.9 ± 16.3 (6-71) months. The quality of cartilage regeneration was evaluated by the International Cartilage-Repair Score (ICRS)-Cartilage Repair Assessment (CRA). Eleven lesions (36.7%) were classified as CRA grade I (normal) and 19 lesions (63.3%) as grade II (nearly normal). Concerning the degree of defect repair, 25 lesions (83.3%) were repaired up to the height of the surrounding articular retropatellar cartilage. Five lesions (16.7%) showed 75% repair of defect depth. The border zone was completely integrated into the surrounding articular cartilage shoulder in 28 lesions (93.3%) and demarcated within 1mm in 2 lesions (6.7%). Macroscopically and by probing, 12 lesions (40%) had intact smooth surface, 17 lesions (56.7%) had fibrillated surface and 1 lesion (3.3%) had small, scattered fissures. A negative correlation was found between the overall repair assessment score and the defect size (r2 = -0.430, p = 0.046) and between integration into border zone and defect size (r2 = -0.340, p = 0.045). A positive correlation was found between macroscopic appearance and age (r2 = + 0.384, p = 0.036). All-arthroscopic ACI using chondrospheres® (ACT3D) for full-thickness retropatellar articular cartilage defects proved to be reproducible and reliable. The advantage of the procedure is that it is minimal invasive. Arthroscopic second-look demonstrated a high grade of normal or nearly normal cartilage regeneration. Although statistically significant differences were not observed, larger defect size and younger age may compromise the result of overall repair. III.

Predictors for an unsuccessful conservative treatment of patients with medial patellar plica syndrome.

In several cases persistent medial knee pain remains after conservative treatment in patients with medial patellar plica syndrome. In recent literature accepted criteria for surgical indication are lacking. In this retrospective study patients after conservative treatment were evaluated to identify predictors for an unsuccessful outcome. 117 Patients with medial patellar plica syndrome between 2016 and 2019 were retrospectively evaluated. All patients received conservative treatment for three months. Surgery was indicated due to failed conservative treatment (n = 76) with persistent medial knee pain and restriction of activity after 3months. Preoperative MRI analysis, Lysholm score, pain by the visual analog scale (VAS), postoperative sports participation (RTS) and Tegner activity score were collected at least 12months after definite treatment. Statistical analysis was performed to evaluate differences between patients with successful and unsuccessful conservative treatment. There were significant differences in the clinical and radiological findings between patients with successful and unsuccessful conservative treatment. Patients with failed conservative treatment showed a significant larger diameter of the medial patellar plica (0.8 ± 0.3mm vs. 1.6 ± 0.4mm; p < 0.05) and a significant higher rate of contact of the plica to the adjacent cartilage. Furthermore, these patients reported a significant higher rate of medial knee pain from flexion to extension and snapping symptoms. At final follow-up the patient-reported outcome by means of Lysholm score (96.25 vs. 95.93), RTS (96.2% vs. 97%) and Tegner activity score (6.0 vs. 6.01) was excellent after conservative and surgical treatment. There were no statistical differences in the preoperative and postoperative outcomes between both. The diameter of a medial patellar plica and contact of the plica to the retropatellar cartilage as well as clinical signs like persistent medial knee pain from flexion to extension with snapping symptoms might be predictors for an unsuccessful conservative treatment and the need for surgical intervention in patients with painful medial patellar plica syndrome.

Correlation of T2* relaxation times of the retropatellar cartilage with tibial tuberosity\u2013trochlea groove distance in professional soccer players

The tibial tuberosity–trochlear groove (TT–TG) distance is a radiographic measurement that is used to quantify malalignment of the patellofemoral joint (PFJ) in cross-sectional imaging. There is an ongoing debate about the impact of the TT–TG-distance on lateral patellar instability and the initiating of cartilage degeneration. In this prospective study, the association of T2* relaxation times and TT–TG distances in professional soccer players was analyzed. 36 knees of 18 professional soccer players (age: 21 ± 2.8 years) were evaluated. Participants underwent knee MRI at 3 T. For qualitative image analysis, fat-saturated 2D PD-weighted Fast Spin Echo (FSE) and T1-weighted FSE sequences were used. For quantitative analysis, T2* measurements in 3D data acquisitions were performed. In a qualitative analysis there was no structural cartilage damage and no abnormalities of the patellar and trochlea shape. The highest T2* values (26.7 ± 5.9 ms) were observed in the central compartment of the patella. The mean TT–TG distance was 10 ± 4 mm (range 3–20 mm). There was no significant correlation between TT–TG distance and T2* relaxation times in all three compartments of the retropatellar cartilage. Our study shows that so long as patellar and trochlear morphology is normal, TT–TG distance alone does not affect the tissue structure of the retropatellar cartilage in professional soccer players.

Increased femoral antetorsion correlates with higher degrees of lateral retropatellar cartilage degeneration, further accentuated in genu valgum.

The role of increased femoral antetorsion (femAT) as a contributor to patellofemoral (PF) osteoarthritis (OA) is unknown. The purpose of this study was to investigate whether increased femAT was associated with advanced cartilage degeneration in the lateral PF joint. Patients who underwent complete radiographic workup for surgical intervention due to OA in any knee joint compartment were included. Cartilage morphology according to the International Cartilage Repair Society (ICRS) cartilage lesion classification system in the PF joint, femoral and tibial torsion, frontal leg axis, and tibial tuberosity-trochlear groove (TT-TG) distance were assessed. Increased femAT was defined as > 20° according to previous reports. A total of 144 patients were included. Ninety-seven patients had a femAT of < 20° and 45 of > 20°. A significant odds ratio (OR) was found for lateral retropatellar (OR 3.5; p = 0.02) ICRS grade 3 and 4 cartilage degeneration and increased femAT ≥ 20°. In the medial PF compartment, increased femAT had an inverse effect (OR 0.16; p = 0.01). No significant ORs were found for TT-TG distance, tibial torsion, or leg axis. The lateral retropatellar ICRS grade showed a linear correlation to increased femAT values. In valgus knees, isolated lateral PF OA had an even more pronounced correlation to increased femAT (p = 0.004). Increased femAT showed higher grades of lateral retropatellar cartilage degeneration, which was even more pronounced in valgus knees. Cohort study: Level III.

Why do MPFL reconstructions fail today?

Aims and Objectives:The medial patellofemoral ligament (MPFL) is the most important passive stabilizer of the patella. In recurrent lateral patellar dislocations reconstruction of the MPFL with an autologous tendon transplant is a frequently performed surgical procedure that shows a low redislocation rate between 1%-7%. However, a complication rate of up to 26% and a reoperation rate of 4% has also been observed. The question, therefore, arises which parameter determines MPFL reconstruction failure. Thus, the purpose of this study was to identify reasons for MPFL reconstruction failure with regard to patients’ complaints leading to reoperation.Materials and Methods:Between July 2015 and May 2019 28 patients (M/F 9/19; mean age 27 ± 8 years) with postoperative complaints after MPFL reconstructive surgery had to undergo revision surgery. Preoperative failure analysis included clinical examination (ROM, ReDPAT, J-sign, and Patella-Glide Test) and radiological imaging with regard to anatomical risk factors of patellar instability and MPFL tunnel positioning. Anatomical predisposition was assessed according to Dejour’s classification of trochlear dysplasia, tibial tuberosity-trochlear groove distance, tibial tuberosity-posterior cruciate ligament distance, patellar height, varus/valgus malalignment and torsional profile.Results:Three major reasons for revision surgery were identified: (1) patellar redislocation, (2) limited range of motion (ROM), and (3) anterior knee pain (AKP). Sixteen of the 28 patients (57%) suffered from recurrent patellar dislocation. Severe trochlear dysplasia (type B/D according to Dejour) (44%), valgus deformity (19%), increased patellar height (19%), and misplaced femoral drill channels (31%) could be identified as risk factors for redislocation. An increased TT-TG (>20mm) or TT-PCL (>24mm) distance could not be observed in any patient in this group. Limited ROM with an average maximum flexion ability of about 92 ± 26° was observed in 10 of the 28 patients (36%), of which 9 patients additionally complained of AKP. Misplaced femoral drill channels (80%), severe trochlear dysplasia (type B/D according to Dejour) (20%) and postoperative decreased patellar height (20%) could be identified as risk factors for postoperative limited ROM. Other reasons for postoperative AKP were increased femoral antetorsion (n=1) and retropatellar cartilage damage (n=2) without any loss of ROM.Conclusion:Recurrent dislocation of the patella, limited ROM and AKP were identified as most common complications after MPFL reconstruction leading to revision surgery. Failures are mainly due to neglected bony risk factors of patellar instability (trochlear dysplasia, patella alta and valgus deformity) and to misplaced femoral drill channels. Appropriate patient selection and an accurate surgical technique appear mandatory for a good clinical outcome when patellar instability is treated solely with an MPFL reconstruction.

Intraarticular Nodular Fasciitis in the Knee Joint with &amp;lt;i&amp;gt;USP6&amp;lt;/i&amp;gt;-Gene Rearrangement&amp;lt;br/&amp;gt;—A Case Report with Special Attention to Diagnostics of Intraarticular Lesions

Background: Nodular fasciitis (NF) is currently considered a self-limited clonal neoplastic process. It shares the rearrangement of USP6-gene with aneurysmal bone cysts and myositis ossificans. The presented case is of interest as this is a rare site of presentation of NF; so far only few single cases of intraarticular NF have been reported with documented USP6-gene rearrangement. Intraarticular neoplasias of the knee joint are rare; the most frequent being tenosynovial giant cell tumor (TSGCT). Given a nationwide annual incidence rate of 14 for the lower extremity and about 75% affecting the knee joint about 10 new cases involving the knee joint can be expected per 1 million persons/year. All other types of benign neoplasms are comparably rare while malignant intraarticular processes are extremely rare with most of them reported as single case studies. Aim: We report our case to emphasize the importance of preoperative diagnostics including the option of biopsy. Intraarticular malignant processes are extremely rare and frequently are operated on accidently with negative consequences for the patient. Tactics and techniques to treat benign processes depend on the correct pathologic diagnosis. Case presentation: The 38 year old man noticed slowly increasing swelling of his left knee joint after wakeboarding. Because of continuing discomfort 2 months later MRI diagnostic revealed, apart from retropatellar cartilage lesions, a popliteal mass compatible with a Baker cyst. The lesion of interest (later diagnosed as NF) was neither recognized by the radiologist nor the treating clinician. During the following 8 months the patient felt increasing swelling of the knee joint. The repeat MRI documented the crescent intraarticular solid synovial mass in the medial patellofemoral recess without signs of hemosiderin impregnation. A percutaneous sonographically guided 16G needle biopsy was performed. Histologically, bland myofibroblastic proliferation suggestive of nodular fasciitis (NF) was found. The next generation sequencing (NGS) demonstrated the presence of MYH9-USP6 gene fusion, confirming the diagnosis of NF. The lesion was excised under arthroscopic control. At 1 year follow-up the patient is asymptomatic. Conclusion: The case is of interest because of its rare pathology. The decision how to treat was based on pathologic biopsy diagnostics including the USP6-gene rearrangement. In view of similar presentation of the rare malignancies we also want to stress the importance of definitive diagnostics which generally are possible only through biopsy.

The Relationship between Chondromalacia Patella, Medial Meniscal Tear and Medial Periarticular Bursitis in Patients with Osteoarthritis.

BackgroundThis study investigated the presence of bursitis in the medial compartment of the knee (pes anserine, semimembranosus-tibial collateral ligament, and medial collateral ligament bursa) in osteoarthritis, chondromalacia patella and medial meniscal tears.Patients and methodsRadiological findings of 100 patients undergoing magnetic resonance imaging with a preliminary diagnosis of knee pain were retrospectively evaluated by two radiologists. The first radiologist assessed all patients in terms of osteoarthritis, chondromalacia patella and medial meniscal tear. The second radiologist was blinded to these results and assessed the presence of bursitis in all patients.ResultsMild osteoarthritis (grade I and II) was determined in 55 patients and severe osteoarthritis (grade III and IV) in 45 cases. At retropatellar cartilage evaluation, 25 patients were assessed as normal, while 29 patients were diagnosed with mild chondromalacia patella (grade I and II) and 46 with severe chondromalacia patella (grade III and IV). Medial meniscus tear was determined in 51 patients. Severe osteoarthritis and chondromalacia patella were positively correlated with meniscal tear (p < 0.001 and p = 0.018, respectively). Significant correlation was observed between medial meniscal tear and bursitis in the medial compartment (p = 0.038). Presence of medial periarticular bursitis was positively correlated with severity of osteoarthritis but exhibited no correlation with chondromalacia patella (p = 0.023 and p = 0.479, respectively). Evaluation of lateral compartment bursae revealed lateral collateral ligament bursitis in 2 patients and iliotibial bursitis in 5 patients.ConclusionsWe observed a greater prevalence of bursitis in the medial compartment of the knee in patients with severe osteoarthritis and medial meniscus tear.

Alterations in structural macromolecules and chondrocyte deformations in lapine retropatellar cartilage 9 weeks after anterior cruciate ligament transection.

The structural integrity and mechanical environment of the articular cartilage matrix directly affect chondrocyte deformations. Rabbit models of early osteoarthritis at 9 weeks following anterior cruciate ligament transection (ACLT) have been shown to alter the deformation behavior of superficial zone chondrocytes in mechanically loaded articular cartilage. However, it is not fully understood whether these changes in cell mechanics are caused by changes in structural macromolecules in the extracellular matrix. Therefore, the purpose of this study was to characterize the proteoglycan content, collagen content, and collagen orientation at 9 weeks post ACLT using microscopic techniques, and relate these changes to the altered cell mechanics observed upon mechanical loading of cartilage. At 9 weeks following ACLT, collagen orientation was significantly (p < 0.05) altered and proteoglycan content was significantly (p < 0.05) reduced in the superficial zone cartilage matrix. These structural changes either in the extracellular or pericellular matrix (ECM and PCM) were also correlated significantly (p < 0.05) with chondrocyte width and height changes, thereby suggesting that chondrocyte deformation response to mechanical compression in early OA changes primarily because of alterations in matrix structure. However, compared to the normal group, proteoglycan content in the PCM from the ACLT group decreased less than that in the surrounding ECM. Therefore, PCM could play a key role to protect excessive chondrocyte deformations in the ACLT group. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:342-350, 2018.

All-Arthroscopic Suture Fixation of Patellar Osteochondritis Dissecans

Osteochondritis dissecans of the knee, despite its cause, is characterized by the impairment of the subchondral bone. Failure of its spontaneous healing makes surgical fixation often necessary. The patella is less affected than other locations in the knee. Its surgical treatment remains a challenge due to the thickness of the lesion and the complex approach of the retropatellar cartilage. Arthroscopy has the theoretical advantage to avoid a possible arthrotomy; however, the retrograde application of fixation materials does not guarantee good fragment compression and may lead to cartilage penetration and damage. The purpose of this Technical Note is to present a reproducible, full arthroscopic suture fixation technique for patellar osteochondritis dissecans lesions. By using the posterior cruciate tibial drill guide, absorbable sutures are passed through the center and the peripheral borders of the lesion resulting in a “spider-parachute-type” fixation with direct fragment compression.

Retropatellar cartilage morphology and kneeling ability: cartilage wear and kneeling function of TKA patients

Objectives: To investigate the retro-patellar cartilage (RPC) morphology and the patterns of retropatellar cartilage wear as well as the patients’ kneeling ability to determine whether the kneeling ability is related to the area and pattern of wear in the cartilage. Methods: 30 patients undergoing primary TKAs participated in this study. The patients were seen in the preoperative assessment clinics and consented to allow intraoperative photographing of their retro patellar cartilage. These photographs were used to determine the area and pattern of wear by using Image J software. The total area of the retropatellar cartilage and the area of wear was measured and used to calculate the percentage of RPC wear. The percentages of retro patellar cartilage wear for all the patients were linked with their kneeling ability before the surgery. Results: 15 patients (cases numbered 1-15, termed group A) were able to kneel, and 15 patients (cases numbered 16-30, termed group B) were unable to kneel. The % of wears for all RPC images measured 3 times with a week interval and the average of the records in the 1st, 2nd, and 3rd week recorded for statistical analysis. Mean % of RPC wears in-group A was (15%), and in-group B was (36%). Intra-Rater and Inter-Rater Reliability statistically assessed by using Intraclass Correlation Coefficient. Patients who able to kneel (Group A) had normal RPC superior surfaces with no damages in comparison with patients who unable to kneel (Group B) who had damaged superior surfaces medially and laterally. All the RPC surfaces (Superior, Middle and Inferior) were damaged in Group B patients (Unable to kneel). Conclusion: No direct association was found between the retropatellar cartilage damage and the kneeling ability. The most damaged areas were found in the middle and lower thirds of retropatellar cartilage.

Surgical treatment of patellar instability: clinical and radiological outcome after medial patellofemoral ligament reconstruction and tibial tuberosity medialisation.

The aim of this retrospective study was to analyse clinical and radiological outcome after medial patellofemoral ligament reconstruction (MPFLR) and tibial tuberosity medialisation (TTM) in patients with recurrent patellar instability. Thirty-five patients were included between 2008 and 2012. According to defined criteria such as tibial tuberosity-trochlear groove (TTTG) distance, hyperpression on the lateral patella facet and lateral retropatellar cartilage damage either MPFLR (group A) or TTM (group B) was performed: 18 patients underwent TTM, the other 17 patients underwent MPFLR. At a mean of 25.4±9.7 (group A) and 35.2±17.6months (group B) patients were clinically and radiologically reviewed. Validated knee scores such as Kujala, Lysholm and Tegner score were evaluated. In both groups one patient reported of a non-traumatic patellar redislocation. Patients who underwent MPFLR (group A) had less pain postoperatively during activity according to the Visual Analogue Scale (group A: 2.0±2.1 points, group B: 3.9±2.3 points). Retropatellar cartilage damage increased in group B from grade 1 (range: 1-3) preoperatively to grade 2 (range 1-3) postoperatively (p>0.05). All other clinically evaluated items, as well as the applied knee scoring systems, indicated no significant difference (p>0.05) and displayed good to excellent results. MPFLR and TTM leed to good clinical results despite its own indications. For this reason-in selected cases-TTM may still be a suitable procedure for surgical treatment of patellar instability. However, patients treated by TTM (group B) revealed an increased retropatellar cartilage damage as well as significantly more pain during activity.