Faculty Bibliography

BACKGROUND:Since the publication of the American Academy of Pediatrics (AAP) clinical practice guideline for brief resolved unexplained events (BRUEs), a few small, single-center studies have suggested low yield of diagnostic testing in infants presenting with such an event. We conducted this large retrospective multicenter study to determine the role of diagnostic testing in leading to a confirmatory diagnosis in BRUE patients. METHODS:Secondary analysis from a large multicenter cohort derived from 15 hospitals participating in the BRUE Quality Improvement and Research Collaborative. The study subjects were infants < 1 year of age presenting with a BRUE to the emergency departments (EDs) of these hospitals between October 1, 2015, and September 30, 2018. Potential BRUE cases were identified using a validated algorithm that relies on administrative data. Chart review was conducted to confirm study inclusion/exclusion, AAP risk criteria, final diagnosis, and contribution of test results. Findings were stratified by ED or hospital discharge and AAP risk criteria. For each patient, we identified whether any diagnostic test contributed to the final diagnosis. We distinguished true (contributory) results from false-positive results. RESULTS:Of 2036 patients meeting study criteria, 63.2% were hospitalized, 87.1% qualified as AAP higher risk, and 45.3% received an explanatory diagnosis. Overall, a laboratory test, imaging, or an ancillary test supported the final diagnosis in 3.2% (65/2036, 95% confidence interval [CI] 2.7%-4.4%) of patients. Out of 5163 diagnostic tests overall, 1.1% (33/2897, 95% CI 0.8%-1.5%) laboratory tests and 1.5% (33/2266, 95% CI 1.0%-1.9%) of imaging and ancillary studies contributed to a diagnosis. Although 861 electrocardiograms were performed, no new cardiac diagnoses were identified during the index visit. CONCLUSIONS:Diagnostic testing to explain BRUE including for those with AAP higher risk criteria is low yield and rarely contributes to an explanation. Future research is needed to evaluate the role of testing in more specific, at-risk populations.

Injury to the anterior cruciate ligament (ACL) can result in recurrent instability, impairment, and progressive joint damage in athletes who return to high-risk sports activities. ACL reconstruction often is indicated. With refinement of surgical techniques and accelerated rehabilitation, the number of complications following ACL reconstruction has greatly decreased since the 1980s. Nevertheless, ACL reconstruction remains a complex procedure with multiple steps and many possible complications. Understanding the incidence and etiology of the more common complications associated with ACL reconstruction during the preoperative and postoperative periods is important to manage (if not avoid) the risk of these complications.

Recent developments in patellar instability have focused on the passive restraints against mediolateral patellar motion. Viewed from this perspective, muscle alignment is considered secondary because, although muscle forces are important, their ability to cause or prevent patellar dislocation depends on passive stability or the lack thereof. In the normal knee, the patella seats quickly in the trochlea in early flexion, so that the ligamentous restraints are important only near full extension. In the unstable patellofemoral joint, the trochlea frequently is deficient and patella alta often exists. In such cases, the ligaments assume a greater role in preventing excessive lateral patellar displacement. The most pressing questions at the moment are: 1) which of the anatomical abnormalities must be corrected, alone or in combination, to prevent further patellar instability; and 2) what is the relative risk of corrective procedures compared to the natural history or competing surgical approaches? These questions must be addressed by clinical trials. Only a minority of patients who experience patellar dislocation will redislocate the patella, and surgical treatment does not always yield results that are superior to conservative care. Treatment recommendations should be based on an individual's risk of recurrent dislocation, pain, and disability, a thorough understanding of his or her anatomy, and clear treatment objectives. Lateral release has no role in the treatment of a hyperlax patellofemoral joint, as it adds additional laxity to a system that is already unstable. If surgery is performed, current evidence suggests techniques aimed at repair or reconstruction of the passive retinacular restraints are as effective as more extensive procedures at preventing subsequent dislocations. Among the latter procedures, realignment procedures use active muscle forces to help seat the patella in the femoral groove; however, biomechanical costs are associated with this approach and superior results have not been demonstrated with distal and combined realignments compared with more limited proximal procedures.