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Background:Tibial tuberosity anteromedialization (TTA) is a well-established treatment option for patellofemoral chondral disease that is resistant to nonoperative treatment. However, the prognostic factors of this procedure are unknown.Purpose:To analyze the prognostic factors correlated with the midterm outcomes of TTA for patellofemoral chondral disease and determine the survivorship.Study Design:Case series; Level of evidence, 4.Methods:Indications of TTA for chondral disease included skeletal maturity, age Results:From January 2003 to December 2013, among 76 eligible patients, 69 patients (78 knees, 74.4% female) were included, with a mean follow-up of 67.9 ± 34.5 months (range, 24-163 months) and a mean age at the time of surgery of 43.5 ± 16.1 years. The mean preoperative WOMAC-SF (17.8 ± 5.3) and Kujala (49.3 ± 15.6) scores significantly ( P < .001) improved after surgery (WOMAC-SF: 6.6 ± 6.9; Kujala: 74.2 ± 20.5). The patients graded their operated knee as 7.2 ± 2.1 of 10 points, on average, and stated that they would undergo the surgery again in 58 (74.4%) cases. A WOMAC-SF score of >7 points (34.6% of knees) in the multiple regression model was associated with age >45 years (odds ratio [OR], 10.4; 95% CI, 2.0-55.0) and increased femoral anteversion (OR, 7.9; 95% CI, 1.4-44.1). A Kujala score of 45 years (OR, 12.0; 95% CI, 2.6-56.2) and foot pronation (OR, 5.1; 95% CI, 1.3-20.4). Patient satisfaction of Conclusion:Overall, good outcomes and survivorship (77% at 108 months) were obtained in this case series. However, 25.6% of the patients would not undergo the surgery again. Increased age, increased femoral anteversion, foot pronation, and postoperative patellofemoral crepitus were identified as negative prognostic factors.

In the last two decades, many surgical techniques have been described for articular cartilage repair. Reliable histological scoring systems are fundamental tools to evaluate new procedures. Several histological scoring systems have been described, and these can be divided in elementary and comprehensive scores, according to the number of sub-items. The aim of this study was to test the inter- and intra-observer reliability of ten main scores used for the histological evaluation of in vivo cartilage repair. The authors tested the starting hypothesis that elementary scores would show superior intra- and inter-observer reliability compared with comprehensive scores. Fifty histological sections obtained from the trochlea of New Zealand Rabbit and stained with Safranin-O fast green were used. The histological sections were analysed by 4 observers: 2 experienced in cartilage histology and 2 inexperienced. Histological evaluations were performed at time 1 and time 2, separated by a 30-day interval. The following scores were used: Mankin, O’Driscoll, Pineda, Wakitani, Fortier, Selleres, ICRS, ICRSII, Oswestry (OsScore) and modified O’Driscoll. Intra- and inter-observer reliability were evaluated for each score. In addition, the pavement–ceiling effect and the Bland–Altman Coefficient of Repeatability were then evaluated for each sub-item of every score. Intra-observer reliability was high for all observers in every score, even though the reliability was significantly lower for non-expert observers compared with expert counterparts. In terms of Coefficient of Repeatability, some scores performed better (O’Driscoll, Modified O’Driscoll and ICRSII) than others (Fortier, Seller). Inter-observer reliability was high for all observers in every score, but significantly lower for non-expert compared with expert observers. In expert hands, all the scores showed high intra- and inter-observer reliability, independently of the complexity. Although every score has advantages and disadvantages, ICRSII, O’Driscoll and Modified O’Driscoll scores should be preferred for the evaluation of in vivo cartilage repair in animal models.

Minced chondral fragments are becoming popular as a source of cells for cartilage repair, as a growing interest is developing towards one-stage procedures to treat cartilage lesions. The purpose of this study is to (A) compare cell outgrowth from cartilage fragments of adult and young donors using two different types of scaffolds and (B) evaluate the influence of transforming-growth-factor-β1 (TGF-β1) and granulocyte colony-stimulating factor (G-CSF) on chondrocyte behaviour. In part (A) cartilage fragments from adult and young donors were either loaded onto an HA-derivative injectable paste scaffold or onto an HA-derivative membrane scaffold. Construct sections were then examined for cell counting after 1, 2 and 3 months. In part (B) only membrane scaffolds were prepared using cartilage fragments from young donors. Constructs were cultured either in standard growth medium or in the presence of specific growth factors, such as TGF-β1 or G-CSF or TGF-β1 + G-CSF. After 1 month, construct sections were examined for cell counting. Expression of chondrocyte markers (SOX9, CD151, CD49c) and proliferative markers (β-catenin, PCNA) was assessed using immunofluorescence techniques, both in unstimulated construct sections and in cells from unstimulated and stimulated construct cultures. Part (A): histological analysis showed age-dependent and time-dependent chondrocyte migration. A significant difference (p

One-step techniques are a promising approach for cartilage repair. This study introduces a simple chondrocyte culturefree approach with autologous cartilage fragments loaded onto a mixed scaffold composed of high molecular weight hyaluronic acid derivative felt (Hyaff-11), injectable human fibrin glue (Tisseel) and autologous platelet-rich plasma (PRP). Nanoindentation of goat samples showed mechanical properties close to native goat-trochelarcartilage

Background: The use of allogenic juvenile chondrocytes or autologous chondral fragments has shown promising laboratory results for the repair of chondral lesions.Hypothesis: Juvenile chondrocytes would not affect matrix production when mixed with adult chondrocytes or cartilage fragments.Study Design: Controlled laboratory study.Methods: Cartilage sources consisted of 3 adult and 3 juvenile (human) donors. In part 1, per each donor, juvenile chondrocytes were mixed with adult chondrocytes in 5 different proportions: 100%, 50%, 25%, 12.5%, and 0%. Three-dimensional cultures in low-melt agarose were performed. At 6 weeks, biochemical and histologic analyses were performed. In part 2, isolated adult, isolated juvenile, and mixed 3-dimensional cultures (1:1) were performed with chondral fragments (Results: Part 1: Biochemical and histologic analyses showed that isolated juvenile cultures performed significantly better than mixed and isolated adult cultures. No significant differences were noted between mixed cultures (1:1) and isolated adult cultures. Part 2: Biochemical and histologic results at 6 weeks showed that mixed cartilage fragment cultures performed better than isolated adult cultures in terms of proteoglycans/DNA ratio ( P = .014), percentage of safranin O–positive cells ( P = .012), Bern score ( P = .001), and collagen type II. No statistically significant difference was noted between juvenile and mixed cultures.Conclusion: Extracellular matrix production of juvenile chondrocytes is inhibited by adult chondrocytes. The addition of juvenile cartilage fragments to adult fragments improves matrix production, with a positive interaction between the 2 sources.Clinical Relevance: Even if the underlying mechanisms are still unknown, this study describes the behavior of juvenile/adult cocultures using both chondrocytes and cartilage fragments, with potential for new research and clinical applications.

Femoral interference screw divergence is a potential pitfall associated with ACL reconstruction through transtibial tunnel technique, as angles greater than 15 jeopardize graft fixation. Our mathematical model theorizes the proper degrees of knee flexion during femoral screw insertion and the correct screwdriver position to obtain a minimal divergence of the screw in the femoral tunnel. The cadaveric study confirms our method

Articular cartilage possesses low intrinsic healing property due to its lack of vascularity and progenitor cells. Thus, damage to the hyaline cartilage may lead to a progressive degeneration of the joint and eventually to osteoarthritis (OA). In the last years, different surgical techniques have been introduced in the clinical practice to overcome this issue. Bone marrow stimulation, for example, is a widely known method to allow cell invasion from the bloodstream to the site of damage. However, the reparative tissue has different morphological and biomechanical properties when compared to the native cartilage. In particular, the newly formed fibrocartilage has a low amount of proteoglycans and a higher concentration of type I collagen. This different matrix composition leads to a decrease in the mechanical strength and to a poor integration of the reparative tissue with the native cartilage.

The diagnosis and the prompt treatment of early osteoarthritis (OA) represent vital steps for delaying the onset and progression of fully blown OA, which is the most common form of arthritis, involving more than 10 % of the world’s population older than 60 years of age. Nonsurgical treatments such as physiotherapy, anti-inflammatory medications, and other disease-modifying drugs all have modest and short-lasting effect. In this context, the biological approaches have recently gained more and more attention. Growth factors, blood derivatives, such as platelet concentrates, and mesenchymal adult stem cells, either expanded or freshly isolated, are advocated amongst the most promising tool for the treatment of OA, especially in the early phases. Primarily targeted towards focal cartilage defects, these biological agents have indeed recently showed promising results to relieve pain and reduce inflammation in patients with more advanced OA as well, with the final aim to halt the progression of the disease and the need for joint replacement. However, despite of a number of satisfactory in vitro and pre-clinical studies, the evidences are still limited to support their clinical efficacy in OA setting.

To evaluate if the degree of chondral fragmentation affected extracellular matrix (ECM) production in cartilage fragment autograft implantation in vitro.Cartilage was taken from 5 donors undergoing total hip replacement (mean age, 65.6 years; standard deviation [SD], 3). The cartilage was minced to obtain 4 groups with different fragment sizes: (1) "fish scale" (diameter, 8 mm; thickness, 0.3 mm), (2) cubes with 2-mm sides, (3) cubes with 1-mm sides, and (4) cartilage paste (0.3 mm). The cultures were maintained in chondrogenic medium for 6 weeks. Biochemically, a proteoglycan (PG):DNA ratio was calculated as the best approximation of ECM production per cell. The ratio between PG released in the culture medium and the PG in the neocartilage (PGrel:PG) was used as a matrix stability index. Histologically, the slides were stained with safranin O fast green and collagen type II immunostaining. The titration of safranin O-positive cells and the Bern score were calculated.Regarding the PG:DNA ratio, group 4 performed significantly better than groups 1 (P = .001) and 3 (P = .02), whereas group 2 performed better than group 1 (P = .03). No significant difference was found regarding the PGrel:PG ratio and safranin O-positive cells. Regarding the Bern score, group 4 performed significantly better than groups 1 (P = .02), 2 (P = .04), and 3 (P = .03).We conclude that human cartilage fragmentation significantly affects ECM production in vitro. Increased fragmentation enhances ECM production.Assuming a similar behavior in vivo, we recommend mincing the cartilage into small pieces when performing the cartilage fragment autograft implantation technique in order to increase ECM production. Further in vitro studies investigating cartilage of younger nonarthritic donors, as well as in vivo studies, are needed.

To investigate the state of the art regarding Cartilage Autograft Implantation System (CAIS) or Particulated Juvenile Allograft Cartilage (PJAC).The authors searched the English literature regarding CAIS and PJAC. The search strategy was: (particulated cartilage) OR autologous cartilage fragments. All basic science articles were included. Clinical articles with less than 10 patients treated and less than 6 mo of follow-up were excluded. With these criteria, a total of 17 articles were available for the present review.PJAC and CAIS are relatively novel techniques for cartilage repair. Good basic science evidence was described to support the concept. Although the preliminary clinical reports show encouraging results, clinical data are still limited, especially for CAIS. The indications for both techniques need to be precisely defined (age of the patients, size of the lesion, and involvement of the subchondral bone), together with other debated issues.In conclusion, the authors can state that encouraging preliminary results are available for both techniques. However, further studies are necessary to precisely determine the indications, surgical techniques, and long term outcomes for PJAC and CAIS.

This study proposes a single-step therapeutic approach for osteochondral defects using autologous cartilage fragments loaded onto a scaffold composed of a hyaluronic acid (HA) derivative, human fibrin glue (FG) and autologous platelet-rich-plasma (PRP), in a rabbit model. The aim is to demonstrate the in vitro outgrowth of chondrocytes from cartilage fragments and the in vivo formation of a functional repair tissue. In vitro: minced articular cartilage was loaded onto two different types of scaffold (paste or membrane) according to two different HA preparations (injectable HA-derivative or HA-derivative felt). In vivo: trochlear osteochondral defects were created in 50 adult rabbits, which were then assigned to 5 different treatment groups: cartilage fragments loaded onto membrane scaffolds with FG (Group 1) or without FG (Group 2); membrane scaffolds alone with FG (Group 3) or without FG (Group 4); empty defects (Group 5). Membrane scaffolds were used “in vivo” for simpler preparation and better adhesive properties. Repair processes were evaluated histologically and by immunohistochemistry at 1, 3, and 6 months. An in vitro time-dependent cell outgrowth from cartilage fragments was observed with both types of scaffolds. At 6 months, in vivo, cartilage fragment-loaded scaffolds induced significantly better repair tissue than the scaffold alone using histological scoring. Repair in Group 2 was superior to that in any of the control groups (p

Articular cartilage lesions represent one of the major unsolved problems in orthopedic surgery due to the limited capacity of articular cartilage for self-repair following trauma. The biological response of cartilage to injury varies depending on the extent of the traumatic event. When a lesion is confined to the superficial layer, the repair process is not initiated, as the inflammatory stimulus is too weak to stimulate the resident chondrocytes surrounding the lesion; consequently, the defect persists. However, when a full-thickness lesion occurs, reaching the vessels of the subchondral bone, the inflammatory stimulus is more important. Bleeding from the bone marrow occurs, allowing the access of growth factors and reparative cells to the lesion site. These cells are mainly fibroblasts in addition to a low percentage of mesenchymal stem cells. As a result, the newly formed reparative tissue differs from the normal hyaline cartilage in term of morphology, biochemical composition, and biomechanical properties. For these reasons it is called fibrocartilage. The aim of this chapter is to review the morphology, composition, and biomechanical function of normal cartilage and to present an analysis of the response of the cartilage tissue to the different traumas.

The aim of this anatomic descriptive cadaver study is to evaluate the entrance points of cross-pins and the possible chondral damages, using a two cross-pin femoral fixation device via anteromedial portal, during anterior cruciate ligament (ACL) reconstruction. Twenty fresh-frozen cadaver knees (12 cadavers) were tested. We employed the Rigidfix Cross Pin device (Mitek, Norwood, MA), designed to use two biodegradable pins (PLA, length 42 mm, diameter 2.7 mm). Instead of PLA pins, we used color coded metallic pins. Femoral tunnel drilling and cross-pin guide insertions were performed through the anteromedial portal. We gave three positions to the cross-pin guide: 0 degrees , 45 degrees and 90 degrees slope, referring to the horizontal plane. Per each position, we inserted two metallic pins. We recorded and subdivided the pin holes, in three different groups: Group A (0 degrees ); B (45 degrees ); C (90 degrees of slope). Then a wide dissection has been implemented. Group A: 6 knees (30%) had two pins inside the cartilage of the lateral femoral condyle; 10 knees (50%) had one pin inside the cartilage; and 4 knees (20%) had both pins out of the cartilage. Group B: 7 knees (35%) had two pins inside the cartilage; 12 knees (60%) had one pin inside the cartilage; and one knee (5%) had both pins out of the cartilage. Group C: 7 knees (35%) had two pins inside the cartilage; and 13 knees (65%) had one pin inside the cartilage. The risk of chondral injury, using this technique, is high: from 80% (group A) to 100% (Group C) to have at least one pin inside the cartilage. The use of Rigidfix via AM portal is not recommended for routine ACL reconstruction.