Mechanisms of post-traumatic osteoarthritis after ACL injury.

Anterior cruciate ligament (ACL) rupture is a common and devastating injury with long-term sequelae that include meniscal tears, chondral injury, and an increased risk of knee osteoarthritis (OA). ACL reconstruction is recommended to protect against knee instability, reduce the likelihood of meniscal tears and further surgery, and enable earlier return to sporting activities. ACL reconstruction, however, does not reduce the incidence of early-onset OA.

Fluoroquinolones impair tendon healing in a rat rotator cuff repair model: a preliminary study.

Background: Recent studies suggest that fluoroquinolone antibiotics predispose tendons to tendinopathy and/or rupture. However, no investigations on the reparative capacity of tendons exposed to fluoroquinolones have been conducted.

Hypothesis: Fluoroquinolone-treated animals will have inferior biochemical, histological, and biomechanical properties at the healing tendon-bone enthesis compared with controls.

The human meniscus: a review of anatomy, function, injury, and advances in treatment.

Meniscal injuries are recognized as a cause of significant musculoskeletal morbidity. The menisci are vital for the normal function and long-term health of the knee joint. The purpose of this review is to provide current knowledge regarding the anatomy and biomechanical functions of the menisci, incidence, injury patterns and the advancements in treatment options of meniscal injury.

Can platelet-rich plasma enhance anterior cruciate ligament and meniscal repair?

The use of platelet-rich plasma (PRP) to improve clinical outcome following a soft tissue injury, regeneration, and repair has been the subject of intense investigation and discussion. This article endeavors to relate clinical and basic science strategies focused on biological augmentation of the healing response in anterior cruciate ligament (ACL) and meniscus repair and replacement using PRP. Therein, a translational feedback loop is created in the literature and targeted towards the entire multidisciplinary team.

The effect of platelet-rich plasma on muscle contusion healing in a rat model.

Background: Current therapy for muscle contusions is usually limited to nonsteroidal anti-inflammatory drugs and/or use of the RICE principle (rest, ice, compression, elevation); thus, other forms of treatment that can potentially accelerate the rate of healing are desirable.

Hypotheses: A local injection of platelet-rich plasma (PRP) would lead to accelerated healing rates compared with controls; also, delayed administration of PRP would lead to a blunted response compared with immediate treatment.

Study Design: Controlled laboratory study.

Updates in biological therapies for knee injuries: tendons.

Tendons are subjected to tendinopathies caused by inflammation, degeneration, and weakening of the tendon, due to overuse and trauma, which may eventually lead to tendon rupture. Recently, there has been increasing interest in biological approaches to augment tissue healing. Tendon healing occurs through a dynamic process with inflammation, cellular proliferation, and tissue remodeling.

Image based weighted center of proximity versus directly measured knee contact location during simulated gait.

To understand the mechanical consequences of knee injury requires a detailed analysis of the effect of that injury on joint contact mechanics during activities of daily living. Three-dimensional (3D) knee joint geometric models have been combined with knee joint kinematics to dynamically estimate the location of joint contact during physiological activities-using a weighted center of proximity (WCoP) method. However, the relationship between the estimated WCoP and the actual location of contact has not been defined.

Effect of immediate and delayed high-strain loading on tendon-to-bone healing after anterior cruciate ligament reconstruction.

Background: We previously demonstrated, in a rat anterior cruciate ligament (ACL) graft reconstruction model, that the delayed application of low-magnitude-strain loading resulted in improved tendon-to-bone healing compared with that observed after immediate loading and after prolonged immobilization. The purpose of this study was to determine the effect of higher levels of strain loading on tendon-to-bone healing.

Methods: ACL reconstruction was carried out in a rat model in three randomly assigned groups: high-strain daily loading beginning on either (1) postoperative day one (immediate-loading group; n = 7) or (2) postoperative day four (delayed-loading group; n = 11) or (3) after prolonged immobilization (immobilized group; n = 8).

Assessment of rotator cuff repair integrity using ultrasound and magnetic resonance imaging in a multicenter study.

Background: This study compared ultrasound and magnetic resonance imaging (MRI) evaluation of the repaired rotator cuff to determine concordance between these imaging studies.

Methods: We performed a concordance study using the data from a prospective nonrandomized multicenter study at 13 centers. A suture bridge technique was used to repair 113 rotator cuff tears that were between 1 and 4 cm wide.

Biologic augmentation of tendon-to-bone healing: scaffolds, mechanical load, vitamin D, and diabetes.

Biologic and synthetic scaffolds, mechanical loads, vitamin D, and diabetes can affect tendon and tendon-to-bone healing, muscle recovery, and growth in the perioperative period. Despite important advances in technical approaches to achieve surgical repair of soft tissues in a minimally invasive fashion, structural healing after tendon-to-bone repair remains a formidable challenge that is complicated by our incomplete knowledge of complex natural biologic processes and a diverse patient population with various comorbidities and deficiencies. Scientific research has led to promising strategies for promoting a structural repair that recapitulates the native anatomy of the tendon or enthesis.

The basic science behind biologic augmentation of tendon-bone healing: a scientific review.

Rotator cuff tears are common musculoskeletal injuries that often require surgical repair. Despite advances in surgical techniques, including progression from a single row of anchors to double-row constructs, recurrent tearing or failure to heal still complicates 10% to 94% of repairs. The surgical treatment of rotator cuff tears is aimed at providing the best mechanical environment for tendon healing.

The effect of mechanical load on tendon-to-bone healing in a rat model.

Background: Joint motion is commonly prescribed after tendon repair surgeries such as rotator cuff repairs; however, the ideal rehabilitation program to optimize tendon-to-bone healing is unknown.

Hypotheses: (1) Delayed loading would result in a mechanically stronger and better organized tendon-to-bone interface compared with prolonged immobilization or immediate loading. (2) Low-magnitude load would lead to superior healing compared with high-magnitude load.

Augmentation of tendon-to-bone healing.

Tendon-to-bone healing is vital to the ultimate success of the various surgical procedures performed to repair injured tendons. Achieving tendon-to-bone healing that is functionally and biologically similar to native anatomy can be challenging because of the limited regeneration capacity of the tendon-bone interface. Orthopaedic basic-science research strategies aiming to augment tendon-to-bone healing include the use of osteoinductive growth factors, platelet-rich plasma, gene therapy, enveloping the grafts with periosteum, osteoconductive materials, cell-based therapies, biodegradable scaffolds, and biomimetic patches.

Restoration of articular cartilage.

➤ Novel (i.e., quantitative and semiquantitative) cartilage imaging techniques can evaluate cartilage composition to augment information obtained from traditional magnetic resonance imaging sequences that detail morphology.

Muscle injuries in athletes: enhancing recovery through scientific understanding and novel therapies.

Context: Muscle injuries are extremely common in athletes and often produce pain, dysfunction, and the inability to return to practice or competition. Appropriate diagnosis and management can optimize recovery and minimize time to return to play.

Evidence Acquisition: Contemporary papers, both basic science and clinical medicine, that investigate muscle healing were reviewed.

Allograft replacement for absent native tissue.

Context: Structural instability due to poor soft tissue quality often requires augmentation. Allografts are important biological substitutes that are used for the symptomatic patient in the reconstruction of deficient ligaments, tendons, menisci, and osteochondral defects. Interest in the clinical application of allografts has arisen from the demand to obtain stable anatomy with restoration of function and protection against additional injury, particularly for high-demand patients who participate in sports.

Novel treatment of a failed quadriceps tendon repair in a diabetic patient using a patella-quadriceps tendon allograft.

Recurrent quadriceps tendon rupture is a debilitating condition that may be challenging to treat, especially in the presence of systemic disease such as diabetes mellitus (Bedi et al., J Shoulder Elbow Surg 19:978-988, 2010; Chbnou and Frenette, Am J Physiol Regul Integr Comp Physiol 5:R952-R957, 2004; Chen et al., J Shoulder Elbow Surg 5:416-421, 2003).

Successful Fusion of the Proximal Tibiofibular Joint with Osteogenic Protein-1 (OP-1) Augmentation.

Proximal tibiofibular joint (PTFJ) instability is rare, but when encountered can be difficult to manage. Previously reported forms of treatment, including cast immobilization, soft tissue repairs and reconstructions, and fibular head resection have met with limited success. Another option is PTFJ arthrodesis-however, fusion can be difficult and ankle pain after surgery is not uncommon.

Platelet-rich plasma in orthopaedic applications: evidence-based recommendations for treatment.

Autologous platelet-rich plasma (PRP) therapies have seen a dramatic increase in breadth and frequency of use for orthopaedic conditions in the past 5 years. Rich in many growth factors that have important implications in healing, PRP can potentially regenerate tissue via multiple mechanisms. Proposed clinical and surgical applications include spinal fusion, chondropathy, knee osteoarthritis, tendinopathy, acute and chronic soft-tissue injuries, enhancement of healing after ligament reconstruction, and muscle strains.

Future trends for unicompartmental arthritis of the knee: injectables & stem cells.

Arthritis is one of the most frequent musculoskeletal problems, causing pain, disability, and a significant economic burden. In this article, we discuss current nonsurgical injectable treatment options as well as future trends for cartilage lesions and early arthritis of the knee. We cover some potential treatments for knee osteoarthritis, including stem cell and gene therapies.

Effect of diet-induced vitamin D deficiency on rotator cuff healing in a rat model.

Background: Few studies have considered hormonal influences, particularly vitamin D, on healing.

Hypothesis: Vitamin D deficiency would have a negative effect on the structure of the healing tendon-bone interface in a rat model and would result in decreased tendon attachment strength.

Study Design: Controlled laboratory study.

Restoration of the meniscus: form and function.

Over the past 2 decades there has been a profound shift in our perception of the role of the meniscus in the knee joint. Orthopaedic opinion now favors salvaging and restoring the damaged meniscus where possible. Basic science is characterizing its form (anatomy) and functionality (biological and biomechanical) in an attempt to understand the effect of meniscal injury and repair on the knee joint as a whole.

Posterior interosseous neuropathy: electrodiagnostic evaluation.

Electrodiagnostic studies are used to anatomically localize nerve injuries. These tests help differentiate between cervical radiculopathies, brachial plexopathies, and peripheral nerve injuries. They also help to identify or rule out other underlying neurological diseases and disorders.

The role of platelet-rich plasma in inducing musculoskeletal tissue healing.

Background: Platelet-rich plasma [PRP] has received increasing interest across many musculoskeletal disciplines and has been widely applied clinically to stimulate tissue healing in numerous anatomical regions. The known actions of platelet-derived factors suggest that PRP may have significant potential in the treatment of pathological conditions of cartilage, tendon, ligament, and muscle.

Purpose: The aim of this manuscript is to review current literature regarding the biology of PRP and the efficacy of using PRP to augment healing of tendon ligament and muscle injuries, as well as early osteoarthritis.