JAAOS

JAAOS, Volume 12, No. 5


Dislocation after total hip arthroplasty.

Dislocation is one of the most common complications after total hip arthroplasty (THA). Risk factors include neuromuscular and cognitive disorders, patient non-compliance, and previous hip surgery. Surgical considerations that must be addressed include approach, soft-tissue tension, component positioning, impingement, head size, acetabular liner profile, and surgeon experience. Recent improvements in posterior soft-tissue repair after primary THA have shown a reduced incidence of dislocation. When dislocation occurs, a thorough history, physical examination, and radiographic assessment help in choosing the proper intervention. Closed reduction usually is possible, and nonsurgical management frequently succeeds in preventing recurrence. When these measures fail, first-line revision options should target the underlying etiology. This most often involves tensioning or augmentation of soft tissues, as in capsulorrhaphy or trochanteric advancement; correction of malpositioned components; or improving the head-to-neck ratio. If instability persists, or if a primary THA repeatedly dislocates without a clear cause, a constrained cup or bipolar femoral prosthesis may be as effective as a salvage procedure.

    • Keywords:
    • Arthroplasty

    • Replacement

    • Hip|Hip Dislocation|Hip Prosthesis|Humans|Prosthesis Failure|Risk Factors

    • Subspecialty:
    • Adult Reconstruction

Fibrous dysplasia.

Fibrous dysplasia is a developmental disorder of bone that can present in a monostotic or polyostotic form. Primarily affecting adolescents and young adults, it accounts for 7% of benign bone tumors. Many of the asymptomatic lesions are found incidentally; the remainder present with symptoms of swelling, deformity, or pain. Fibrous dysplasia has been associated with multiple endocrine and nonendocrine disorders and with McCune-Albright and Mazabraud's syndromes. The etiology remains unclear, but molecular biology suggests a mutation in the G(s)alpha subunit and activation of c-fos and other proto-oncogenes. Fibrous dysplasia has a characteristic radiographic appearance. Most cases do not require intervention, but those that do usually are managed surgically with curettage, bone grafting, and, in some cases, internal fixation. When some intervention is necessary but surgery is not practical, treatment is with bisphosphonates. The prognosis generally is good, although poor outcomes are more frequent in younger patients and in those with polyostotic forms of the disease. The risk of malignant transformation is low.

    • Keywords:
    • Bone Transplantation|Curettage|Diphosphonates|Fibrous Dysplasia

    • Monostotic|Fibrous Dysplasia

    • Polyostotic|Genes

    • fos|Humans|Mutation|Treatment Outcome

    • Subspecialty:
    • Pediatric Orthopaedics

Free vascularized fibular grafts for reconstruction of skeletal defects.

Nourished by the peroneal vessels, the versatile free vascularized fibular graft can be transferred to reconstruct skeletal defects of the extremities. It may be combined with skin, fascia, muscle, and growth-plate tissue to address the needs of the recipient site. It may be cut transversely and folded to reconstruct the length and width of tibial or femoral defects. The main indications for this graft are defects larger than 5 to 6 cm or with poor vascularity of the surrounding soft tissues. Detailed preoperative planning, experience in microvascular techniques, and careful postoperative follow-up are necessary to minimize complications and improve outcome. The free vascularized fibular graft has been successfully applied as a reconstruction option in patients with traumatic or septic skeletal defect, after tumor resection, and has shown promise in patients with congenital pseudarthrosis.

    • Keywords:
    • Bone Neoplasms|Bone Transplantation|Fibula|Humans|Leg Injuries|Postoperative Complications|Pseudarthrosis|Reconstructive Surgical Procedures

    • Subspecialty:
    • Trauma

Fusion in posttraumatic foot and ankle reconstruction.

Despite appropriate acute treatment, many foot and ankle injuries result in posttraumatic arthritis. Arthrodesis remains the mainstay of treatment of end-stage arthritis of the foot and ankle. An understanding of the biomechanics of the foot and ankle, particularly which joints are most responsible for optimal function of the foot, can help guide reconstructive efforts. A careful history and physical examination, appropriate radiographs, and, when necessary, differential selective anesthetic blocks help limit fusion to only those joints that are causing pain. Compression fixation, when possible, remains the treatment of choice. When bone defects are present, however, neutralization fixation may be necessary to prevent a secondary deformity that could result from impaction into a bone defect.

    • Keywords:
    • Ankle Injuries|Ankle Joint|Arthritis|Arthrodesis|Biomechanics|Foot Injuries|Foot Joints|Humans|Postoperative Complications

    • Subspecialty:
    • Trauma

    • Foot and Ankle

Management of pediatric femoral shaft fractures.

Femoral shaft fractures are the most common major pediatric injuries managed by the orthopaedic surgeon. Management is influenced by associated injuries or multiple trauma, fracture personality, age, family issues, and cost. In addition, child abuse should be considered in a young child with a femoral fracture. Nonsurgical management, usually with early spica cast application, is preferred in younger children. Surgery is common for the school-age child and for patients with high-energy trauma. In the older child, traction followed by casting, external fixation, flexible intramedullary nails, and plate fixation have specific indications. The skeletally mature teenager is treated with rigid intramedullary fixation. Potential complications of treatment include shortening, angular and rotational deformity, delayed union, nonunion, compartment syndrome, overgrowth, infection, skin problems, and scarring. Risks of surgical management include refracture after external fixator or plate removal, osteonecrosis after rigid antegrade intramedullary nail fixation, and soft-tissue irritation caused by the ends of flexible nails.

    • Keywords:
    • Adolescent|Bone Nails|Bone Plates|Casts

    • Surgical|Child|Child

    • Preschool|External Fixators|Femoral Fractures|Femur|Fracture Fixation|Fracture Fixation

    • Intramedullary|Humans|Multiple Trauma|Postoperative Complications

    • Subspecialty:
    • Trauma

    • Pediatric Orthopaedics

New therapies in tendon reconstruction.

Despite the use of various types of grafts, no surgical treatment currently exists to restore a tendon to its normal condition. Tissue engineering techniques are being used to develop therapies for tendon reconstruction. Biologic and synthetic scaffolds can both repair tendon defects and improve healing by allowing for the regeneration of the tendon's natural biologic composition to restore its mechanical capacity. This process can be further enhanced through augmentation methods such as cell seeding, growth factor implantation, and gene therapy.

    • Keywords:
    • Gene Therapy|Growth Substances|Humans|Tendon Injuries|Tendons|Tissue Engineering|Tissue Transplantation|Wound Healing

    • Subspecialty:
    • Sports Medicine

    • Basic Science

The acutely dislocated knee: evaluation and management.

Acute knee dislocations are uncommon orthopaedic injuries. Because they often spontaneously reduce before initial evaluation, the true incidence is unknown. Dislocation involves injury to multiple ligaments of the knee, resulting in multidirectional instability. Associated meniscal, osteochondral, and neurovascular injuries are often present and can complicate management. The substantial risk of associated vascular injury mandates that vascular integrity be confirmed by angiography in all suspected knee dislocations. Evaluation and initial management must be performed expeditiously to prevent limb-threatening complications. Definitive management of acute knee dislocation remains a matter of debate; however, surgical reconstruction or repair of all ligamentous injuries likely can help in achieving the return of adequate knee function. Important considerations in surgical management include surgical timing, graft selection, surgical technique, and postoperative rehabilitation.

    • Keywords:
    • Acute Disease|Humans|Joint Instability|Knee Dislocation|Knee Joint|Magnetic Resonance Imaging

    • Subspecialty:
    • Sports Medicine

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