JAAOS, Volume 26, No. 8

The Anterolateral Complex and Anterolateral Ligament of the Knee

The anterolateral structures of the knee have recently garnered considerable interest regarding their role in rotatory knee instability related to anterior cruciate ligament tears. Isolated anterior cruciate ligament reconstruction may not always restore rotatory stability of the knee. In these patients, additional procedures, such as lateral reconstruction or tenodesis, may be indicated. The anatomy of the anterolateral structures of the knee has been well described. Histologic and anatomic studies have reported conflicting findings regarding the presence of a discrete ligament. The biomechanical role of the anterolateral capsule in restraining internal tibial rotation has been described as negligible. The existing body of research on the anterolateral knee structures provides insight into the composition of the anterolateral complex of the knee.

      • Subspecialty:
      • Knee

      • Adult Reconstruction

    Radiation Exposure and Health Risks for Orthopaedic Surgeons

    Orthopaedic surgeons are routinely exposed to intraoperative radiation and, therefore, follow the principle of “as low as reasonably achievable” with regard to occupational safety. However, standardized education on the long-term health effects of radiation and the basis for current radiation exposure limits is limited in the field of orthopaedics. Much of orthopaedic surgeons’ understanding of radiation exposure limits is extrapolated from studies of survivors of the atomic bombings in Hiroshima and Nagasaki, Japan. Epidemiologic studies on cancer risk in surgeons and interventional proceduralists and dosimetry studies on true radiation exposure during trauma and spine surgery recently have been conducted. Orthopaedic surgeons should understand the basics and basis of radiation exposure limits, be familiar with the current literature on the incidence of solid tumors and cataracts in orthopaedic surgeons, and understand the evidence behind current intraoperative fluoroscopy safety recommendations.

        • Subspecialty:
        • General Orthopaedics

      Effects of Vitamin D on Skeletal Muscle and Athletic Performance

      Vitamin D is known to be important for calcium homeostasis and bone metabolism. It also has important direct effects on skeletal muscle. Unlike authentic vitamins, which cannot be synthesized in the body, vitamin D is produced in the skin using sunlight. Through its nuclear receptor (ie, vitamin D receptor) located throughout the body, including skeletal muscle, vitamin D initiates genomic and nongenomic pathways regulating multiple actions, including myocyte proliferation and growth. In some studies, vitamin D supplementation has been shown to increase muscle strength, particularly in people who are vitamin D deficient. Higher serum levels of vitamin D are associated with reduced injury rates and improved sports performance. In a subset of the population, vitamin D appears to play a role in muscle strength, injury prevention, and sports performance.

          • Subspecialty:
          • Sports Medicine

        Periprosthetic Tibial Fractures

        Periprosthetic fractures around total knee arthroplasty have become an increasingly common and challenging orthopaedic problem. Appropriate management of these fractures depends on careful scrutiny of radiographs and a thorough clinical history to exclude the diagnosis of a periprosthetic infection. In a periprosthetic tibial fracture with a stable, well-aligned tibial component and well-aligned mechanical tibial axis, the fracture can be successfully managed with closed reduction and cast immobilization; meticulous follow-up is essential to ensure that the alignment is maintained. Major fracture displacement, tibial component instability, and tibial component malalignment are all indications for surgical intervention. The ideal surgical intervention depends on the fracture characteristics and the stability and alignment of the tibial component.

            • Subspecialty:
            • Foot and Ankle

          Routine Plain Radiographs in the Setting of Atraumatic Shoulder Pain: Are They Useful?

          Introduction: Plain radiographs of the shoulder are routinely obtained for patients presenting with atraumatic shoulder pain. The diagnostic utility of these radiographs is debatable.

          Methods: Patients presenting for the first time to a shoulder clinic with atraumatic shoulder pain received a plain radiographic series. After considering their medical history and physical examination, we made a preliminary diagnosis and formulated a tentative treatment plan. We then reviewed the radiographs and determined whether the addition of these radiographs altered the diagnosis and/or treatment.

          Results: A total of 343 patients met the inclusion criteria. Age >50 years (odds ratio, 3.3; 95% confidence interval, 1.9 to 5.8; P < 0.00001) and weakness in forward elevation (odds ratio, 2.9; 95% confidence interval, 1.6 to 5.4; P = 0.0003) were associated with the presence of radiographic findings. Plain radiographs altered the proposed diagnosis in only 14.9% (51/343) of cases. However, clinical management was changed in only 1.7% of cases. Plain radiographs had no effect on clinical management in 97.4% of patients younger than 50 years.

          Discussion: Plain radiographs rarely alter the diagnosis or affect management in the setting of atraumatic shoulder pain, particularly in patients younger than 50 years. Patients may be exposed to unnecessary radiation, and the healthcare system as a whole may be burdened with the increased cost of this imaging modality.

          Level of Evidence: Level II (diagnostic).

              • Subspecialty:
              • Shoulder and Elbow

            Routine Use of Radiostereometric Analysis in Elective Hip and Knee Arthroplasty Patients: Surgical Impact, Safety, and Bead Stability

            Background: Radiostereometric analysis (RSA) accurately assesses arthroplasty implant performance and is routinely used for research purposes. Because of its efficacy in detecting implant failure in research subjects, we deployed the use of RSA beads for routine surveillance in all elective total hip and total knee arthroplasty patients.

            Methods: We retrospectively compared 143 patients who received RSA beads intraoperatively with 343 patients who did not receive RSA beads. Using RSA images, we assessed bead stability at 6 weeks and 1 year postoperatively.

            Results: There were no intraoperative complications in the RSA group and two in the control group. No differences were found between groups for the surgical time and the expected blood loss. At 6 weeks, 99.5% of beads were considered to be stable, with stability increasing to 99.7% of beads at 1 year.

            Conclusion: The routine use of RSA bead insertion is a safe procedure and may provide the ability to assess implant fixation in clinical practice.

                • Subspecialty:
                • Knee

                • Adult Reconstruction

                • Hip

              Alterations in Range of Motion and Clinical Outcomes After Femoroplasty in Asians

              Introduction: The restoration of range of motion after surgery in patients with femoroacetabular impingement syndrome is considered an important factor that improves clinical outcomes and determines the quality of life of patients, especially in the Asian population.

              Methods: Arthroscopic femoroplasty was done in 109 Asian patients with cam impingement. The patients were retrospectively evaluated using range of motion and clinical outcomes (Harris Hip Score [HHS], visual analog scale score, Hip Outcome Score–Activity of Daily Living, and Hip Outcome Score–Sports subscales) between preoperative and postoperative conditions, with a follow-up period of >2 years.

              Results: The increments of hip motion were an internal rotation of 10.1° (P < 0.05) at 3 postoperative months and an external rotation of 11.8° (P < 0.05) at approximately 6 postoperative months; both were maintained at 2 postoperative years. Mean clinical outcomes improved from 69.1 to 82.1 for HHS, from 6.0 to 2.1 for the visual analog scale score, and from 40.1 to 68.7 for the Hip Outcome Score–Sports Subscale at 6 postoperative months (P < 0.05) and were maintained at 2 years. Younger subjects (<45 years of age) displayed even greater improvements in the HHS and Hip Outcome Score–Activity of Daily Living/Sports Subscale than the other group (≥45 years of age) (P < 0.05).

              Conclusion: Patients who underwent arthroscopic femoroplasty showed improvements in internal rotation at 3 months postoperatively and external rotation at approximately 6 months postoperatively. In addition, younger age (<45 years and the restoration of rotational hip motion resulted in better clinical outcomes.

              Level of Evidence: III a.

                  • Subspecialty:
                  • Adult Reconstruction

                  • Hip