João Espregueira-Mendes

Biomechanical considerations in the pathogenesis of osteoarthritis of the knee

AbstractOsteoarthritis is the most common joint disease and a major cause of disability. The knee is the large joint most affected. While chronological age is the single most important risk factor of osteoarthritis, the pathogenesis of knee osteoarthritis in the young patient is predominantly related to an unfavorable biomechanical environment at the joint. This results in mechanical demand that exceeds the ability of a joint to repair and maintain itself, predisposing the articular cartilage to premature degeneration. This review examines the available basic science, preclinical and clinical evidence regarding several such unfavorable biomechanical conditions about the knee: malalignment, loss of meniscal tissue, cartilage defects and joint instability or laxity. Level of evidence IV.

Anatomy of the proximal tibiofibular joint

This paper describes the anatomy and function of the proximal tibiofibular joint (PTFJ). The physical dimensions of the joint and the topology of the articular surfaces are described. It is noted that the inclination of the joint is variable, and that joints with a steeper slope away from the transverse plane are less mobile. The ligamentous and tendinous attachments are described. Finally, the histological features of the articular surfaces are presented. The clinical importance of the anatomical features is discussed.

Current concepts: tissue engineering and regenerative medicine applications in the ankle joint

Tissue engineering and regenerative medicine (TERM) has caused a revolution in present and future trends of medicine and surgery. In different tissues, advanced TERM approaches bring new therapeutic possibilities in general population as well as in young patients and high-level athletes, improving restoration of biological functions and rehabilitation. The mainstream components required to obtain a functional regeneration of tissues may include biodegradable scaffolds, drugs or growth factors and different cell types (either autologous or heterologous) that can be cultured in bioreactor systems (in vitro) prior to implantation into the patient. Particularly in the ankle, which is subject to many different injuries (e.g. acute, chronic, traumatic and degenerative), there is still no definitive and feasible answer to ‘conventional’ methods. This review aims to provide current concepts of TERM applications to ankle injuries under preclinical and/or clinical research applied to skin, tendon, bone and cartilage problems. A particular attention has been given to biomaterial design and scaffold processing with potential use in osteochondral ankle lesions.

Arthroscopic Repair of Ankle Instability With All-Soft Knotless Anchors

In recent years, arthroscopic and arthroscopically assisted techniques have been increasingly used to reconstruct the lateral ligaments of the ankle. Besides permitting the treatment of several comorbidities, arthroscopic techniques are envisioned to lower the amount of surgical aggression and to improve the assessment of anatomic structures. We describe our surgical technique for arthroscopic, two-portal ankle ligament repair using an all-soft knotless anchor, which is made exclusively of suture material. This technique avoids the need for classic knot-tying methods. Thus it diminishes the chance of knot migration caused by pendulum movements. Moreover, it avoids some complications that have been related to the use of metallic anchors and some currently available biomaterials. It also prevents prominent knots, which have been described as a possible cause of secondary complaints.

Mesenchymal Stem Cell Secretome: A Potential Tool for the Prevention of Muscle Degenerative Changes Associated With Chronic Rotator Cuff Tears:

Background: Massive rotator cuff tears (MRCTs) are usually chronic lesions with pronounced degenerative changes, where advanced fatty degeneration and atrophy can make the tear irreparable. Human mesenchymal stem cells (hMSCs) secrete a range of growth factors and vesicular systems, known as secretome, that mediates regenerative processes in tissues undergoing degeneration. Purpose: To study the effect of hMSC secretome on muscular degenerative changes and shoulder function on a rat MRCT model. Study Design: Controlled laboratory study. Methods: A bilateral 2-tendon (supraspinatus and infraspinatus) section was performed to create an MRCT in a rat model. Forty-four Wistar-Han rats were randomly assigned to 6 groups: control group (sham surgery), lesion control group (MRCT), and 4 treated-lesion groups according to the site and periodicity of hMSC secretome injection: single local injection, multiple local injections, single systemic injection, and multiple systemic injections. Forelimb function was analyzed with the staircase test. Atrophy and fatty degeneration of the muscle were evaluated at 8 and 16 weeks after injury. A proteomic analysis was conducted to identify the molecules present in the hMSC secretome that can be associated with muscular degeneration prevention. Results: When untreated for 8 weeks, the MRCT rats exhibited a significantly higher fat content (0.73% ± 0.19%) compared with rats treated with a single local injection (0.21% ± 0.04%; P < .01) or multiple systemic injections (0.25% ± 0.10%; P < .05) of hMSC secretome. At 16 weeks after injury, a protective effect of the secretome in the multiple systemic injections (0.62% ± 0.14%; P < .001), single local injection (0.76% ± 0.17%; P < .001), and multiple local injections (1.35% ± 0.21%; P < .05) was observed when compared with the untreated MRCT group (2.51% ± 0.42%). Regarding muscle atrophy, 8 weeks after injury, only the single local injection group (0.0993% ± 0.0036%) presented a significantly higher muscle mass than that of the untreated MRCT group (0.0794% ± 0.0047%; P < .05). Finally, the proteomic analysis revealed the presence of important proteins with muscle regeneration, namely, pigment epithelium-derived factor and follistatin. Conclusion: The study data suggest that hMSC secretome effectively decreases the fatty degeneration and atrophy of the rotator cuff muscles. Clinical Relevance: We describe a new approach for decreasing the characteristic muscle degeneration associated with chronic rotator cuff tears. This strategy is particularly important for patients whose tendon healing after later surgical repair could be compromised by the progressing degenerative changes. In addition, both precise intramuscular local injection and multiple systemic secretome injections have been shown to be promising delivery forms for preventing muscle degeneration.

Sport and early osteoarthritis: the role of sport in aetiology, progression and treatment of knee osteoarthritis

Sports activities are considered favourable for general health; nevertheless, a possible influence of sports practice on the development of early osteoarthritis (OA) is a cause for concern. A higher incidence of OA in knees and ankles of former high-impact sports players than in those of the normal population has been shown and it is still debatable whether the cause is either to be recognized generically in the higher number of injuries or in a joint overload. The possibility to address knee OA in its early phases may be strictly connected to the modification of specific extrinsic or intrinsic factors, related to the patient in order to save the joint from further disease progression; these include sport practice, equipment and load. Non-surgical therapies such as continuative muscles reinforce and training play a strong role in the care of athletes with early OA, particularly if professional. There is an overall agreement on the need of an early restoring of a proper meniscal, ligament and cartilage integrity in order to protect the knee and resume sports safely, whereas alignment is a point still strongly debatable especially for professional athletes. Remaining questions still to be answered are the risks of different sports in relation to one another, although an actual protective effect of low-impact sports, such as walking, swimming or cycling, has been recognized on the appearance or worsening of OA, the effect of continuing or ceasing to practice a sport on the natural history of early OA, and even following appropriate treatment is still unknown.

The Meniscus: Basic Science

The menisci are semilunar discs of fibrocartilaginous tissue which play critical roles in knee joint biomechanics [1]. Despite, it has been described in the past as nearly useless with perhaps some minor roles on joint nutrition and stabilization [2]. These complex structures are primarily composed of an interlacing network of collagen fibers (predominantly type I collagen) interposed with cells, and an extracellular matrix (ECM) of proteoglycans and glycoproteins.

Lower Limb Rehabilitation

This short chapter presents the critical thinking behind the guidelines concerning rehabilitation of the lower limb, a wide but incomplete field. Rehabilitation involves the management of injuries, essentially through the use of several different physical agents and therapeutic exercises. Knowledge related to the time frame of tissue healing, inflammatory process, basic training principles, the underlying science, and biomechanics is of utmost importance to every sports medicine professional. Here, essential information is provided about four of the most prevalent injuries of the lower limb: hamstring ruptures, patellar tendinopathy, anterior cruciate ligament rupture (reconstruction), and acute ankle sprains. Rehabilitation goals, treatment strategies, new assessment devices, criteria to return to play, and promising new therapies are discussed. The discussion of injury prevention provides the most up-to-date evidence related to ACL rupture. The current focus is on strength, balance, proprioceptive, and neuromuscular training programs.

PRP for Degenerative Cartilage Disease A Systematic Review of Clinical Studies

Objective: To explore the utilization of platelet-rich plasma (PRP) for degenerative cartilage processes and evaluate whether there is sufficient evidence to better define its potential effects. Design: Systematic literature reviews were conducted in PubMed/MEDLINE and Cochrane electronic databases till May 2015, using the keywords “platelet-rich plasma OR PRP OR autologous conditioned plasma OR ACP AND cartilage OR chondrocyte OR chondrogenesis OR osteoarthritis (OA) OR arthritis.” Results: The final result yielded 29 articles. Twenty-six studies examined PRP administration for knee OA and 3 involved PRP administration for hip OA. The results included 9 prospective randomized controlled trials (RCTs) (8 knee and 1 hip), 4 prospective comparative studies, 14 case series, and 2 retrospective comparative studies. Hyaluronic acid (HA) was used as a control in 11 studies (7 RCTs, 2 prospective comparative studies, and 2 retrospective cohort). Overall, all RCTs reported on improved symptoms compared to baseline scores. Only 2 RCTs—one for knee and one for hip—did not report significant superiority of PRP compared to the control group (HA). Nine out of 11 HA controlled studies showed significant better results in the PRP groups. A trend toward better results for PRP injections in patients with early knee OA and young age was observed; however, lack of uniformity was evident in terms of indications, inclusion criteria, and pathology definitions in the different studies. Conclusion: Current clinical evidence supports the benefit in PRP treatment for knee and hip OA, proven to temporarily relieve pain and improve function of the involved joint with superior results compared with several alternative treatments. Further research to establish the optimal preparation protocol and characteristics of PRP injections for OA is needed.

Notch morphology is a risk factor for ACL injury: a systematic review and meta-analysis

Importance Several bone morphological parameters have been identified in the scientific literature as risk factors for sustaining an anterior cruciate ligament (ACL) injury; however, a clear consensus on which are the most predisposing factors is still missing. Aim This systematic review and meta-analysis aims to investigate the association between bone morphological parameters and the risk of sustaining an ACL injury. Evidence review We conducted a comprehensive search using PubMed, Cochrane Library, Scopus, CINAHL and SPORTDiscus databases from 2005 until 2015. Two authors independently searched for relevant studies that assessed the association between bone morphology and ACL injury. Other search sources were used for hand-searching additional potential studies and the reference list of recent studies was screened. The methodological quality of the included studies was assessed through an adapted scale for radiological studies. A fixed-effects or random-effects model was used accordingly to estimate the mean differences with 95% CIs regarding the association of ACL injury with intercondylar notch (ICN) width, notch width index (NWI) and tibial slopes. Findings 23 studies were included for analysis comprising a total of 3452 participants, 1681 with an ACL injury and 1763 with an intact ACL. The ACL-injured individuals had narrower ICN width (p<0.001), smaller NWI (p=0.005) and steeper tibial slope (p<0.001). Conclusions On the basis of the current scientific literature, narrower ICN widths, smaller NWI and increased tibial slopes put the individual at higher risk of injuring the ACL. Future research should focus on developing indexes for different parameters rather than absolute measurements.