JAAOS

JAAOS, Volume 18, No. 6


A Review of Squeaking Hips

The incidence of squeaking in hip replacement varies for ceramic-on-ceramicand metal-on-metal bearings, and the implications are not fully understood.Contributing factors may include component malposition, edge loading, impingement,third-body particles, and loss of lubrication. However, squeaking is multifactorial,requiring a certain combination of interaction among patient, surgical, andimplant factors. When squeaking is infrequent and function is not impaired,patients should avoid activities that precipitate the squeaking. Surgery isrecommended for persistent or troublesome squeaking, severe malpositioningof components, failure of the implants (including fracture), impingement andsubluxation, and pain. If necessary, the bearing can be changed during surgeryto another ceramic-on-ceramic or to a ceramic-on-polyethylene bearing.

      • Subspecialty:
      • Adult Reconstruction

    Orthopaedic Manifestations of Neurofibromatosis Type 1

    Neurofibromatosis type 1 (NF-1) is an autosomal dominant disease that affects1 in 3,000 persons worldwide. Caf-au-lait macules and peripheral nervesheath tumors (ie, neurofibromas) are the most commonly recognized manifestationsof NF-1. However, NF-1 affects multiple organ systems, and a multidisciplinaryapproach to treatment is required. Management of the orthopaedic manifestationsof NF-1 is often difficult. The most complex manifestations are scoliosis(dystrophic and nondystrophic), congenital pseudarthrosis of the tibia, andproblems related to soft-tissue tumors. Metabolic bone disease is common;many patients are frankly osteopenic, which further complicates treatment.Dystrophic scoliosis, which may be caused by either bony dysplasia or intraspinalpathology, is characterized by early presentation and rapid progression. Pseudarthrosisis common even after instrumented fusion. Nondystrophic scoliosis tends tobehave like adolescent idiopathic scoliosis, although it may present earlierand is associated with a higher rate of pseudarthrosis. Congenital pseudarthrosisof the tibia is a long-bone dysplasia that afflicts patients with NF-1. Managementof this osseous deformity is challenging. Failure to achieve union and refractureare common.

        • Subspecialty:
        • Pediatric Orthopaedics

        • Spine

      Osteofibrous Dysplasia and Adamantinoma

      Osteofibrous dysplasia (OFD) is a rare, benign, fibro-osseous lesion thattypically is seen within the cortex of the tibia in children. Adamantinoma(AD) is a rare, low-grade malignant primary bone tumor that occurs most oftenin the tibia and/or fibula of adolescent persons and young adults; however,it has been reported in other long bones, as well. Immunohistochemical andultrastructural evidence has shown that the neoplastic cell in AD derivesfrom an epithelial lineage. More recently, published reports have describedanother clinical entitydifferentiated or OFD-like ADthat appearsto lie between OFD and AD along a spectrum of disease. Controversy existsas to whether OFD is a precursor lesion to AD or whether OFD may be a residuallesion resulting from a spontaneously regressing AD. Management of OFD variesfrom observation to surgical intervention, depending on the age of the patientand the extent of the lesion. Management of AD requires surgical resectionwith wide margins, followed by appropriate reconstruction, to minimize therisk of local recurrence or metastasis.

          • Subspecialty:
          • Pediatric Orthopaedics

          • Musculoskeletal Oncology

        Recurrent Lumbar Disk Herniation

        Recurrent lumbar disk herniation is the most common complication followingprimary open diskectomy. It is defined as recurrent back and/or leg pain aftera definite pain-free period lasting at least 6 months from initial surgery.Careful neurologic examination is critical, and laboratory tests should beordered to evaluate for infection. Imaging demonstrates disk herniation atthe previously operated level. It is important to differentiate recurrentdisk herniation from postoperative epidural scar because the latter may notbenefit from reoperation. Treatment of recurrent lumbar disk herniation includesaggressive medical management and surgical intervention. Surgical techniquesinclude conventional open diskectomy, minimally invasive open diskectomy,and open diskectomy with fusion. Fusion is necessary in the presence of concomitantsegmental instability or significant foraminal stenosis resulting from diskspace collapse.

            • Subspecialty:
            • Spine

          The Acetabular Labrum: Anatomic and Functional Characteristicsand Rationale for Surgical Intervention

          The past decade has seen unprecedented growth in the number of hip arthroscopies.Acetabular labral tears are the leading indication for arthroscopy of thisjoint. However, labral anatomy and function, as well as the effects of labraltears and surgical outcomes, have only recently been studied. Labral tearsmay cause pain and microinstability of the hip joint. They also may increasefriction within the joint, cartilage consolidation, and strain within thearticular cartilage, thereby possibly resulting in accelerated degenerationof the joint. Partial labrectomy and labral repair are the current surgicaloptions, and basic science data suggest that labral repairs can heal and subsequentlyrestore function. However, a good, validated outcomes measure to adequatelyassess active patients with a painful nonarthritic hip is needed to determinethe efficacy of such repair and aid in managing patient expectations.

              • Subspecialty:
              • Sports Medicine

              • Adult Reconstruction

            The Orthopaedic Implications of Diphosphonate Therapy

            Diphosphonates are among the many commonly prescribed drugs for osteoporosismanagement. These synthetic analogues of physiologically occurring inorganicpyrophosphate bind to the hydroxyapatite crystals of bone. Diphosphonatesact by decreasing the amount of osteoclast-mediated bone resorption by inducingapoptosis and disrupting the mevalonate biosynthetic pathway. Prospectiveclinical trials have shown that diphosphonates increase bone mineral densityand reduce the risk of fracture. Diphosphonates are generally well tolerated,with a low incidence of side effects. They may be administered orally or intravenously;infusions are the most potent. Few studies have directly studied the effectof diphosphonates on the rate of fracture or time to union. Concern existsregarding the long-term safety of diphosphonates, particularly in patientswith osteoporosis. New evidence suggests that long-term therapy may increasethe risk of fracture of the femoral shaft, with possible morphologic and prodromalwarning signs. Further prospective research into the consequences of diphosphonate-mediatedsuppressed bone turnover is needed to elucidate a safe duration of treatment.

                • Subspecialty:
                • General Orthopaedics

                • Adult Reconstruction

                • Basic Science

              Treatment of Glenohumeral Osteoarthritis

              This clinical practice guideline is based on a systematic review of publishedstudies on the treatment of glenohumeral osteoarthritis in the adult patientpopulation. Of the 16 recommendations addressed, nine are inconclusive. Twowere reached by consensusthat physicians use perioperative mechanicaland/or chemical venous thromboembolism prophylaxis for shoulder arthroplastypatients and that total shoulder arthroplasty not be performed in patientswith glenohumeral osteoarthritis who have an irreparable rotator cuff tear.Four options were graded as weak: the use of injectable viscosupplementation;total shoulder arthroplasty and hemiarthroplasty as treatment; avoiding shoulderarthroplasty by surgeons who perform fewer than two shoulder arthroplastiesper year (to reduce the risk of immediate postoperative complications); andthe use of keeled or pegged all-polyethylene cemented glenoid components.The single moderate-rated recommendation was for the use of total shoulderarthroplasty rather than hemiarthroplasty. Management of glenohumeral osteoarthritisremains controversial; the scientific evidence on this topic can be significantlyimproved.

                  • Subspecialty:
                  • Shoulder and Elbow

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