JAAOS

JAAOS, Volume 21, No. 5


Cartilage Regeneration

Cartilage damaged by trauma has a limited capacity to regenerate. Current methods of managing small chondral defects include palliative treatment with arthroscopic débridement and lavage, reparative treatment with marrow-stimulation techniques (eg, microfracture), and restorative treatment, including osteochondral grafting and autologous chondrocyte implantation. Larger defects are managed with osteochondral allograft or total joint arthroplasty. However, the future of managing cartilage defects lies in providing biologic solutions through cartilage regeneration. Laboratory and clinical studies have examined the management of larger lesions using tissue-engineered cartilage. Regenerated cartilage can be derived from various cell types, including chondrocytes, pluripotent stem cells, and mesenchymal stem cells. Common scaffolding materials include proteins, carbohydrates, synthetic materials, and composite polymers. Scaffolds may be woven, spun into nanofibers, or configured as hydrogels. Chondrogenesis may be enhanced with the application of chondroinductive growth factors. Bioreactors are being developed to enhance nutrient delivery and provide mechanical stimulation to tissue-engineered cartilage ex vivo. The multidisciplinary approaches currently being developed to produce cartilage promise to bring to fruition the desire for cartilage regeneration in clinical use.

      • Subspecialty:
      • Basic Science

    Pronator Syndrome and Anterior Interosseous Nerve Syndrome

    Dysfunction of the median nerve at the elbow or proximal forearm can characterize two distinct clinical entities: pronator syndrome (PS) or anterior interosseous nerve (AIN) syndrome. PS is characterized by vague volar forearm pain, with median nerve paresthesias and minimal motor findings. AIN syndrome is a pure motor palsy of any or all of the muscles innervated by that nerve: the flexor pollicis longus, the flexor digitorum profundus of the index and middle fingers, and the pronator quadratus. The sites of anatomic compression are essentially the same for both disorders. Typically, the findings of electrodiagnostic studies are normal in patients with PS and abnormal in those with AIN syndrome. PS is a controversial diagnosis and is typically treated nonsurgically. AIN syndrome is increasingly thought to be neuritis and it often resolves spontaneously following prolonged observation. Surgical indications for nerve decompression include persistent symptoms for >6 months in patients with PS or for a minimum of 12 months with no signs of motor improvement in those with AIN syndrome.

        • Subspecialty:
        • Hand and Wrist

      Synthetic Playing Surfaces and Athlete Health

      Synthetic playing surfaces have evolved considerably since their introduction in the 1960s. Today, third-generation turf is routinely installed in professional, collegiate, and community settings. Proponents of artificial surfaces tout their versatility and durability in a variety of climates. However, the health and injury ramifications have yet to be clearly defined. Musculoskeletal injury is largely affected by the shoe–playing surface interface. However, conclusive statements cannot be made regarding the risk of certain shoe–playing surface combinations because of the variety of additional factors, such as weather conditions, shoe wear, and field wear. Historically, clinical studies have indicated that higher injury rates occur on artificial turf than on natural surfaces. This conclusion is backed by robust biomechanical data that suggest that torque and strain may be greater on artificial surfaces than on natural grass. Recent data on professional athletes suggest that elite athletes may sustain injuries at increased rates on the newer surfaces. However, these surfaces remain attractive to athletes and administrators alike because of their durability, relative ease of maintenance, and multiuse potential.

          • Subspecialty:
          • Sports Medicine

        The Adult Paralytic Foot

        The adult paralytic foot is a common clinical entity. It has numerous neurologic, systemic, and traumatic causes that result in muscle imbalance and foot deformity. A thorough physical examination and diagnostic work-up, as well as an understanding of the relevant functional anatomy, are essential to proper management. Treatment goals include the establishment of a plantigrade foot, elimination of deforming forces, and, when possible, restoration of active motor control.

            • Subspecialty:
            • Foot and Ankle

          Transabdominal Gunshot Wounds of the Hip and Pelvis

          Transabdominal gunshot wounds (GSWs) of the hip and pelvis are those that traverse the gastrointestinal system before entering the pelvis and/or hip. These injuries may be contaminated by bowel contents. Some require urgent surgical intervention; others can be managed nonsurgically. A primary survey with attention to hemodynamic status is of utmost priority. After obtaining hemodynamic stability and addressing abdominal injuries, careful attention must be paid to evaluating hip joint involvement and injuries to the genitourinary and vascular systems. The available literature shows that transabdominal GSW with intra-articular contamination should be urgently débrided and irrigated; extra-articular transabdominal GSW with stable fracture patterns may be managed with observation and empiric antibiotics. Extent of soft-tissue injury dictates the need for wound débridement. Bullets lodged in intra-articular locations should be removed, but retained bullets in other anatomic locations do not necessarily warrant removal.

              • Subspecialty:
              • Trauma

            Wrong-site Spine Surgery

            Wrong-site spine surgery is an adverse event that has potentially devastating consequences for the patient as well as the surgeon. Despite substantial efforts to prevent wrong-site spine surgery, this complication continues to occur and has the potential for serious medical, personal, and legal repercussions. Although systems-based prevention methods are effective in identifying the proper patient, procedure, and region of the spinal column, they cannot be relied on to establish the correct vertebral level during the operation. The surgeon must design and implement a patient-specific protocol to ensure that the appropriate operation is performed on the correct side and level or levels of the spinal column.

                • Subspecialty:
                • Spine

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