Transgluteal Approach for Drainage of Obturator Internus Abscess in Pediatric Patients.

BACKGROUND: Of the locations of peripelvic pyomyositis, infection of the obturator musculature poses a difficult challenge for operative drainage. The anatomic location of the obturator muscles, especially the obturator internus, complicates operative debridement as the surgical approach must safely bypass a large number of neurovascular structures. Realizing the challenges and risks of approaches to the obturator musculature, the purpose of our study was to review a novel, yet simple, posterior approach to the obturator internus. METHODS: We reviewed a case series of children (age 0 to 18 y), who presented to our institution with obturator internus pyomyositis. The patients' demographics, vital signs, laboratory data, and radiographic findings from the initial evaluation were reviewed. Blood and intraoperative culture results were collected. Duration of symptoms and length of hospital stay were also reviewed. Cases of suspected obturator internus abscess were confirmed by magnetic resonance imaging of the pelvis. All patients in this study who met the operative indications were debrided using the posterior transgluteal approach. RESULTS: Five patients were identified who met criteria for isolated obturator internus pyomyositis. Four out of the 5 patients met operative indications and underwent drainage through a transgluteal approach. One patient responded well to antibiotic treatment; therefore, no surgery was indicated. Purulence was expressed in all 4 operative cases. Hospital length of stay ranged from 6 to 14 days. All patients were treated with an IV antibiotic course for 3 to 6 weeks. All patients returned to normal function and activity levels. There were no surgical complications. CONCLUSIONS: This case series has reviewed a new technique for the drainage of an isolated obturator internus abscess. The transgluteal posterior approach is a simple approach that is performed through a single incision with minimal soft-tissue dissection. It avoids the risks and challenges posed by other approaches. Most importantly, our case series, although small, in our experience, has shown that it is a safe and effective approach for drainage of obturator internus abscess. LEVEL OF EVIDENCE: Level IV.

Dilution Effect of Intra-articular Injection Administered After Knee Arthroscopy.

The hypothesis was that agents delivered intra-articularly after knee arthroscopy will be diluted by residual arthroscopic fluid. Diagnostic arthroscopy was performed on six cadaver knees. Each procedure was followed by an intra-articular injection of a dye solution. Intra-articular aspirates were gathered from three locations. With significance set at p < .05, the aspirates were compared with the initial dye concentration and with each other. No significant difference was noted among the sites, indicating that no specific knee area was exposed to a higher dye concentration. There was a significant difference in dye concentration of the aspirates when compared with the dye's initial concentration. The concentration of fluid injected intra-articularly after arthroscopy was diluted by 27%. These data indicate that agents injected into the knee postarthroscopy are significantly diluted. In vitro and in vivo experiments evaluating chondrotoxicity of various anesthetic agents may not accurately reflect the actual concentration of the drug within the knee joint unless dilution effects are taken into account.