Faculty Bibliography

BACKGROUND CONTEXT/BACKGROUND:The intervertebral disc primarily relies on trans-endplate diffusion for the uptake of nutrients and the clearance of byproducts. In degenerative discs, diffusion is often diminished by endplate sclerosis and reduced proteoglycan content. Mechanical loading-induced convection has the potential to augment diffusion and enhance net transport into the disc. The ability of convection to augment disc transport is controversial and has not been demonstrated in vivo. PURPOSE/OBJECTIVE:To determine if loading-induced convection can enhance small molecule transport into the intervertebral disc in vivo. STUDY DESIGN/METHODS:Net transport was quantified via postcontrast enhanced magnetic resonance imaging (MRI) into the discs of the New Zealand white rabbit lumbar spine subjected to in vivo cyclic low rate loading. METHODS:Animals were administered the MRI contrast agent gadodiamide intravenously and subjected to in vivo low rate loading (0.5 Hz, 200 N) via a custom external loading apparatus for either 2.5, 5, 10, 15, or 20 minutes. Animals were then euthanized and the lumbar spines imaged using postcontrast enhanced MRI. The T1 constants in the nucleus, annulus, and cartilage endplates were quantified as a measure of gadodiamide transport into the loaded discs compared with the adjacent unloaded discs. Microcomputed tomography was used to quantify subchondral bone density. RESULTS:Low rate loading caused the rapid uptake and clearance of gadodiamide in the nucleus compared with unloaded discs, which exhibited a slower rate of uptake. Relative to unloaded discs, low rate loading caused a maximum increase in transport into the nucleus of 16.8% after 5 minutes of loading. Low rate loading increased the concentration of gadodiamide in the cartilage endplates at each time point compared with unloaded levels. CONCLUSIONS:Results from this study indicate that forced convection accelerated small molecule uptake and clearance in the disc induced by low rate mechanical loading. Low rate loading may, therefore, be therapeutic to the disc as it may enhance the nutrient uptake and waste product clearance.

The goal of this study was to evaluate the role of portable primary trauma survey radiographs in the evaluation and management of anteroposterior (AP) compression pelvic injuries. A retrospective analysis was conducted at a level I academic trauma center. Twenty-seven adults with AP compressive class pelvic ring injuries who received both portable pelvic radiographs and pelvic computed tomography (CT) imaging in an unbound pelvic state were included. Three orthopedic surgeons performed independent measurements of diastasis on portable pelvic radiographs and coronal pelvic CT reconstructions. Measurement techniques were standardized among observers and were repeated after 8 weeks to assess intraobserver reliability. Nonoperative vs operative treatments were correlated with the initial magnitude of pelvic injury on CT and portable radiographic images. Independent measurements of diastasis on both radiographs and CT scans showed excellent intraobserver reliability (average correlation coefficient, 0.986) and interobserver reliability (average correlation coefficient, 0.979). Compared with diastasis measurements on CT scans, portable pelvic radiographs overestimated diastasis by an average of 49%, or 12.6 mm (P<.0001; 95% confidence interval, 9.6-15.6). Portable pelvic films were less precise than standard pelvic radiographs in measuring the size of femoral head controls (R(2)=0.919 vs 0.759; P=.004). In 12 of the 27 patients evaluated, radiographic indications for operative pelvic fixation were met by portable radiographs but not CT scans, and 11 of these patients ultimately underwent operative fixation. Portable AP pelvic radiographs may distort and exaggerate pelvic bony injuries, especially those involving anterior pelvic structures. Surgeons should use caution when making management decisions based on preliminary portable pelvic radiographs.

OBJECTIVE: Dedicated orthopaedic operating rooms (DOORs) are increasingly popular solutions to reducing after-hours procedures, physician fatigue, and elective schedule disruptions. Although the benefits to surgeons are well understood, there are comparatively few studies that explore the effects of DOORs on patient care. We compared treatments and outcomes for all consecutive patients with femoral neck fractures, 4 years before and 4 years after implementation of a DOOR-based schedule. DESIGN: Retrospective case-control study. SETTING: Level 1 academic trauma center. PATIENTS: A total of 111 consecutive trauma patients undergoing surgical management of isolated OTA group 31-B femoral neck fractures. INTERVENTION: Based on individual patient factors and fracture characteristics, patients were managed with either hemiarthroplasty or open reduction internal fixation (ORIF). MAIN OUTCOME MEASURES: Surgical timing, intervention type, perioperative complications, and postoperative length of stay. RESULTS: Retrospective analysis revealed a significant decrease in after-hour surgery (4 PM-7:30 AM) for all femoral neck fractures (66.7%-19.3%; P < 0.001). No significant differences were found between the rates of arthroplasty versus those of open reduction internal fixation. Patients undergoing surgical treatment for femoral neck fractures after DOOR suffered significantly fewer morbidities, including significantly decreased rates of postoperative intensive care unit admissions, stroke, infections, and myocardial infarction or congestive heart failure exacerbations. We also observed a significant decrease in postoperative mortality (5.6% pre-DOOR vs. 0% post-DOOR; P = 0.04). Patients undergoing hemiarthroplasty experienced a significant shorter hospitalization (14.5 days pre-DOOR vs. 9.9 days post-DOOR; P = 0.04). CONCLUSIONS: In our experience, a weekday DOOR is closely associated with improvements in both patient safety and outcomes. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Langerhans cell histiocytosis is a rare group of disorders without a well-understood etiology. Known formerly as histiocytosis X, the disease has a wide spectrum of clinical presentations, including eosinophilic granuloma (solitary bone lesion), diabetes insipidus, and exophthalmos. It is also known by several eponyms, including Hand-Schüller-Christian disease when it manifests as a triad of cranial bone lesions and Letterer-Siwe disease when it is found in infantile patients with severely disseminated disease. Children aged 5 to 15 years are most commonly affected. Many of these patients initially present to orthopaedic surgeons, and misdiagnosis is frequent. To accurately diagnosis and treat these patients, the orthopaedic surgeon must be familiar with the clinical manifestations and pathophysiology of the disease as well as the treatment guidelines and outcomes for Langerhans cell histiocytosis.

We report the case of a 16-year-old boy with isolated septic arthritis of a lumbar facet. This rare presentation of an infection in a lumbar facet joint occurred after minor trauma sustained in a football game. Septic arthritis of the spinal facet joint is an uncommon phenomenon. Only 5 cases have been reported in immunocompromised pediatric patients. To our knowledge, no case of septic arthritis in an immunocompetent pediatric patient has been reported. An otherwise healthy 16-year-old boy presented with 4 weeks of escalating back pain after a minor athletics-related trauma. Evaluation showed incapacitating pain, lumbar musculature spasms, and the absence of fever, hemodynamic, or neurologic changes. Laboratory values were within normal limits. Magnetic resonance images showed a fluid collection within the L3-L4 facet and a localized abscess. Computed tomographic-guided aspiration showed methicillin-resistant Staphylococcus aureus infection, for which the patient received 6 weeks of vancomycin with complete resolution of symptoms. Refractory lumbago in an adolescent requires careful evaluation.

Chronic musculoskeletal pain results from a complex interplay of mechanical, biochemical, psychological, and social factors. Effective management is markedly different from that of acute musculoskeletal pain. Understanding the physiology of pain transmission, modulation, and perception is crucial for effective management. Pharmacologic and nonpharmacologic therapies such as psychotherapy and biofeedback exercises can be used to manage chronic pain. Evidence-based treatment recommendations have been made for chronic pain conditions frequently encountered by orthopaedic surgeons, including low back, osteoarthritic, posttraumatic, and neuropathic pain. Extended-release tramadol; select tricyclic antidepressants, serotonin reuptake inhibitors, and anticonvulsants; and topical medications such as lidocaine, diclofenac, and capsaicin are among the most effective treatments. However, drug efficacy varies significantly by indication. Orthopaedic surgeons should be familiar with the widely available safe and effective nonnarcotic options for chronic musculoskeletal pain.

A 24-year-old military policeman underwent arthroscopic femoral neck osteoplasty and labral repair of his right hip following failed conservative management of femoroacetabular impingement. His postoperative course was complicated by recurring posterior instability of his right hip initially presenting as a posterior dislocation on postoperative day 19. Iatrogenic disruption of the hip's static stabilizers in the setting of underlying coxa valga is the likely culprit. Although anterior dislocation following hip arthroscopy has been described, posterior dislocation has not. Further, we identified a successful and less-invasive approach to the treatment of this complication, in the form of a spica cast. Prior cases pertaining to post-arthroscopy hip instability have only described operative interventions, such as capsular repair and plication, as effective revision procedures.

BACKGROUND CONTEXT/BACKGROUND:Spinal cord compression associated with pseudohypoparathyroidism (PHP) is an increasingly reported sequelae of the underlying metabolic syndrome. The association of neurologic dysfunction with PHP is not well appreciated. We believe this to be secondary to a combination of underlying congenital stenosis, manifest by short pedicles secondary to premature physeal closure, and hypertrophic ossification of the vertebral bony and ligamentous complexes. PURPOSE/OBJECTIVE:The purpose of this case report is to review the case of spinal stenosis in a child with PHP Type Ia. We are aware of only eight published reports of patients with PHP Type Ia and spinal stenosis-there are only two previously known cases of pediatric spinal stenosis secondary to PHP. STUDY DESIGN/SETTING/METHODS:This is a case report detailing the symptoms, diagnosis, interventions, complications, and ultimate outcomes of a pediatric patient undergoing spinal decompression and fusion for symptomatic stenosis secondary to PHP Type Ia. Literature search was reviewed regarding the reports of spinal stenosis and PHP, and the results are culminated and discussed. PATIENT SAMPLE/METHODS:We report on a 14-year-old obese male with PHP and progressive lower extremity weakness secondary to congenital spinal stenosis. Examination revealed functional upper extremities with spastic paraplegia of bilateral lower extremities. The patient's neurologic function was cautiously monitored, but he deteriorated to a bed-bound state, preoperatively. METHODS:The patient's chart was reviewed, summarized, and presented. Literature was searched using cross-reference of PHP and the terms "spinal stenosis," "myelopathy", "myelopathic," and "spinal cord compression." All relevant case reports were reviewed, and the results are discussed herein. RESULTS:The patient underwent decompression and instrumented fusion of T2-T11. He improved significantly with regard to lower extremity function, achieving unassisted ambulation function after extensive rehabilitation. Results from surgical decompression in previously reported cases are mixed, ranging from full recovery to iatrogenic paraplegia. CONCLUSIONS:The association of neurologic dysfunction with PHP is not well appreciated. It is important to highlight this rare association. Surgical decompression in patients with PHP yields mixed results but may be of greatest efficacy in younger patients who receive early intervention.