There is an increasing awareness on the importance in identifying early phases of the degenerative processes in knee osteoarthritis (OA), the crucial period of the disease when there might still be the possibility to initiate treatments preventing its progression. Early OA may show a diffuse and ill-defined involvement, but also originate in the cartilage surrounding a focal lesion, thus necessitating a separate assessment of these two entities. Early OA can be considered to include a maximal involvement of 50 % of the cartilage thickness based on the macroscopic ICRS classification, reflecting an OARSI grade 4. The purpose of this paper was to provide an updated review of the current status of the diagnosis and definition of early knee OA, including the clinical, radiographical, histological, MRI, and arthroscopic definitions and biomarkers. Based on current evidence, practical classification criteria are presented. As new insights and technologies become available, they will further evolve to better define and treat early knee OA.

The quality of the currently available data on second-generation autologous chondrocyte transplantation is still limited by study designs. The modified CMS has demonstrated better sensitivity and reproducibility with respect to the original score, so it can be recommended for cartilage clinical studies evaluation.

Background Residual rotational instability remains a controversial factor when analysing failure rates of anterior cruciate ligament (ACL) reconstruction. Anatomical and biomechanical studies have demonstrated a very important role of anterolateral structures for rotational control. Revision ACL is considered one of the main indications for a lateral extra‐articular tenodesis (LET). Yet, few series evaluating these procedures are published. Purpose To perform a systematic review of studies that assessed outcomes in patients treated with revision ACL surgery associated with a lateral extra‐articular procedure. Study design Systematic review. Methods A comprehensive literature search was performed in February 2018 using PubMed, Scopus, Web of Search and Cochrane. Inclusion criteria were series of ACL revision reconstructions associated with lateral extra‐articular procedures. Clinical outcomes (Lysholm, subjective IKDC, KOOS, Cincinnati and WOMAC), joint stability measures (Lachman test, pivot‐shift, arthrometer assessment and navigation assessment), graft type, reported chondral and meniscal injury, radiographic outcomes, complications and failures were recorded. Articles were assessed for level of evidence and methodology using a modification of the ACL Methodology Score (AMS) system. Results Twelve studies met the inclusion criteria out of the 231 abstracts; 9 retrospective evaluations, two prospective cohorts and one combination of two populations (a retrospective and prospective series). A total of 851 patients evaluated with a mean age of 28.8 years (range 16–68 years) and a weighted mean follow‐up of 4.9 years (range 1–10 years). The mean time from primary ACL reconstruction to revision was 5.3 years (reported in 7 studies, including 710 patients). The Lysholm, IKDC, and KOOS scores indicated favorable results in studies that reported these outcomes. Objective evaluations reported 86% objective A and B IKDC results, 2.6 mm mean side‐to‐side arthrometric difference and 80% negative pivot‐shift. About 74% of patients returned to their previous sport (evaluated in six studies). Few studies reported radiological evaluation. Fifty‐nine complications (8.0%) and 24 failures (3.6%) were reported. The mean modified ACL Methodology Score was 55.5 (range 32–72). Conclusion Good mid‐term results were obtained for combined revision ACL reconstruction and lateral extra‐articular procedures. Despite the fact that in clinical practice LET are a common indication associated with revision ACL, there are no high‐level studies supporting this technique. Level of evidence IV.

A clinical improvement was found in patients more than 40 years old, who in most cases benefited from second-generation ACI with good results lasting at medium-term follow-up. However, the results were inferior with respect to those previously found for younger populations, and the failure rate at medium-term follow-up was also higher. These findings were consistent in the 2 treatment groups. The only difference was the faster recovery when the arthroscopic approach was used.

It is widely accepted that partial meniscectomy leads to early onset of osteoarthritis (OA). A strong correlation exists between the amount and location of the resected meniscus and the development of degenerative changes in the knee. On the other hand, osteoarthritic changes of the joint alter the structural and functional integrity of meniscal tissue. These alterations might additionally compromise the limited healing capacity of the meniscus. In young, active patients without cartilage damage, meniscus therapy including partial meniscectomy, meniscus suture, and meniscus replacement has proven beneficial effects in long-term studies. Even in an early osteoarthritic milieu, there is a relevant regenerative potential of the meniscus and the surrounding cartilage. This potential should be taken into account, and meniscal surgery can be performed with the correct timing and the proper indication even in the presence of early OA.

BackgroundChondral lesions of the knee represent a challenge for the orthopaedic surgeon. Several treatments have been proposed with variable success rate. Recently, new therapeutic approaches, such as the use of mesenchymal stem cells, have shown promising results. The adipose tissue is a good source of these naturally occurring regenerative cells, due to its abundance and easy access. In addition, it can be used to provide cushioning and filling of structural defects. The 1-year safety and outcome of a single intra-articular injection of autologous and micro-fragmented adipose tissue in 30 patients affected by diffuse degenerative chondral lesions was evaluated.MethodsMicro-fragmented adipose tissue was obtained using a minimal manipulation technique in a closed system. The safety of the procedure was evaluated by recording type and incidence of any adverse event. The clinical outcomes were determined using the KOOS, IKDC-subjective, Tegner Lysholm Knee, and VAS pain scales taken pre-operatively and at 12 months follow-up. A level of at least 10 points of improvement in the scores has been selected as cut-off representing a clinically significant difference.ResultsNo relevant complications nor clinical worsening were recorded. A total median improvement of 20 points has been observed in IKDC-subjective and total KOOS, and a higher percentage of success was found in VAS pain and Tegner Lysholm Knee, where the total median improvement was 24 and 31 points, respectively.ConclusionThe results of this study show the safety and feasibility of using autologous and micro-fragmented adipose tissue in patients affected by diffuse degenerative chondral lesions. The technique is safe, minimally invasive, simple, one-step, with low percentage of complications, and compliant with the regulatory panorama.Electronic supplementary materialThe online version of this article (10.1186/s40634-017-0108-2) contains supplementary material, which is available to authorized users.

PurposeThe increasing awareness on the role of subchondral bone in the etiopathology of articular surface lesions led to the development of osteochondral scaffolds. While safety and promising results have been suggested, there are no trials proving the real potential of the osteochondral regenerative approach. Aim was to assess the benefit provided by a nanostructured collagen–hydroxyapatite (coll-HA) multilayer scaffold for the treatment of chondral and osteochondral knee lesions.MethodsIn this multicentre randomized controlled clinical trial, 100 patients affected by symptomatic chondral and osteochondral lesions were treated and evaluated for up to 2 years (51 study group and 49 control group). A biomimetic coll-HA scaffold was studied, and bone marrow stimulation (BMS) was used as reference intervention. Primary efficacy measurement was IKDC subjective score at 2 years. Secondary efficacy measurements were: KOOS, IKDC Knee Examination Form, Tegner and VAS Pain scores evaluated at 6, 12 and 24 months. Tissue regeneration was evaluated with MRI MOCART scoring system at 6, 12 and 24 months. An external independent agency was involved to ensure data correctness and objectiveness.ResultsA statistically significant improvement of all clinical scores was obtained from basal evaluation to 2-year follow-up in both groups, although no overall statistically significant differences were detected between the two treatments. Conversely, the subgroup of patients affected by deep osteochondral lesions (i.e. Outerbridge grade IV and OCD) showed a statistically significant better IKDC subjective outcome (+12.4 points, p = 0.036) in the coll-HA group. Statistically significant better results were also found for another challenging group: sport active patients (+16.0, p = 0.027). Severe adverse events related to treatment were documented only in three patients in the coll-HA group and in one in the BMS group. The MOCART score showed no statistical difference between the two groups.ConclusionsThis study highlighted the safety and potential of a biomimetic implant. While no statistically significant differences were found compared to BMS for chondral lesions, this procedure can be considered a suitable option for the treatment of osteochondral lesions.Level of evidenceI.Electronic supplementary materialThe online version of this article (doi:10.1007/s00167-017-4707-3) contains supplementary material, which is available to authorized users.

Revision anterior cruciate ligament reconstruction remains a challenge, especially optimising outcome for patients with a compromised knee where previous autogenous tissue has been used for reconstruction. Allograft tissue has become a recognized choice of graft for revision surgery but questions remain over the risks and benefits of such an option. Allograft tendons are a safe and effective option for revision ACL reconstruction with no higher risk of infection and equivalent failure rates compared to autografts provided that the tissue is not irradiated, or any irradiation is minimal. Best scenarios for use of allografts include revision surgery where further use of autografts could lead to high donor site morbidity, complex instability situations where additional structures may need reconstruction, and in those with clinical and radiologic signs of autologous tendon degeneration. A surgeon needs to be able to select the best option for the challenging knee facing revision ACL reconstruction, and in the light of current data, allograft tissue can be considered a suitable option to this purpose. Level of evidence IV.