Revisiting the Anterior Glenoid: An Analysis of the Calcified Cartilage Layer, Capsulolabral Complex, and Glenoid Bone Density.

PURPOSE: In this cadaveric study, we aim to define the basic anatomy of the anterior glenoid with attention to the relationships of calcified cartilage, capsulolabral complex, and osseous morphology of the anterior glenoid. METHODS: Seventeen cadaveric glenoid specimens (14 male, 3 female, mean age 53.9 ± 10) were imaged with micro-computed tomography (CT) and embedded in poly-methyl-methacrylate. Specimens were included for final analysis only if the entire glenoid articular cartilage, labrum, capsule, and biceps insertion were pristine and without evidence of injury, degeneration, or damage during the preparation process. Group 1 members (n = 9) were axially sectioned through 3 to 9 o'clock and 4 to 8 o'clock; group 2 members (n = 8) were radially sectioned through 3, 4, 5, and 9 o'clock. A scanning electron microscope (SEM) analysis quantified the percentage of bone within a 5 × 2.5 mm region at the glenoid rim. Micro-CT, SEM, and light microscopy evaluated the capsulolabral complex and calcified fibrocartilage. RESULTS: A 7 ± 2.1 mm region of calcified fibrocartilage at 4 o'clock was identified from the articular face to the medial glenoid neck supporting the overlying capsulolabral footprint and was >3× thicker at the articular attachment (316 ± 153 µm) versus the glenoid neck (92 ± 66 µm). At 3 to 9 o'clock and 4 to 8 o'clock 79.2% ± 5.4% and 75.2% ± 7.8% of the glenoid osseous width was covered with articular cartilage. The labrum accounted for 13.1% ± 3.4% of the glenoid width at 4 o'clock. SEM analysis demonstrated decreased glenoid bone density at 3, 4, and 5 o'clock (P ≤ .015) and no difference (P = .448) at 9 o'clock versus central subchondral bone. CONCLUSIONS: The capsulolabral footprint contributes significantly to the glenoid face, inserts directly adjacent to the articular cartilage, and extends medially along the glenoid neck. A layer of calcified fibrocartilage lies immediately beneath the capsulolabral footprint and is 3× thicker at the articular insertion compared with the glenoid neck. Lastly, there is a bone density gradient at the anterior-inferior rim versus the central subchondral bone. CLINICAL RELEVANCE: Arthroscopic Bankart repair has been reported to have a significant failure rate in many settings. It is felt that reproducing anatomy with the repair could help improve outcomes. Based on this study's findings, an arthroscopic Bankart technique that most closely reproduces native anatomy and potentially optimizes soft-tissue healing could be performed. This includes removal of 1 to 2 mm of articular cartilage from the glenoid face with anchor placement at this location to appropriately reposition the capsulolabral complex.

Link Between Clinical Predictors of Heterotopic Ossification and Histological Analysis in Combat-Injured Service Members.

BACKGROUND: Heterotopic ossification (HO) is a debilitating condition that occurs following traumatic injury and may restrict range of motion and delay rehabilitation. The timing and efficacy of surgical resection have varied widely, and there is a gap in knowledge between clinical predictors of HO recurrence and histological analysis. METHODS: Thirty-three service members seen at Walter Reed National Military Medical Center for symptomatic HO were enrolled in an institutional review board-approved study. Participants took oxytetracycline on four scheduled days prior to HO resection to determine the mineral apposition rate (bone growth rate). RESULTS: Detailed histological analyses included scanning electron microscopy with backscattered electron imaging and light microscopy. Data indicated that the mineral apposition rate of trauma-induced HO was approximately 1.7 µm/day at the time of operative intervention, which was 1.7 times higher than the rate in non-pathological human bone. The mineral apposition rate and postoperative alkaline phosphatase values were demonstrated to be positively and significantly related (ρ = 0.509, p = 0.026, n = 19). When the analysis was limited to patients with no more than a two-year period from injury to excision (thereby removing outliers who had a longer time period than their counterparts) and traumatic brain injury and nonsteroidal anti-inflammatory drugs (known correlates with HO development) were controlled for in the statistical analysis, the mineral apposition rate and recurrence severity were significantly related (ρ = -0.572, p = 0.041, n = 11). CONCLUSIONS: Data demonstrated a link between benchtop research and bedside care, with the mineral apposition rate elevated in patients with HO and correlated with recurrence severity; however, a larger sample size and more clinical factors are needed to refine this model. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Experimental model of biofilm implant-related osteomyelitis to test combination biomaterials using biofilms as initial inocula.

Currently, the majority of animal models that are used to study biofilm-related infections use planktonic bacterial cells as initial inocula to produce positive signals of infection in biomaterials studies. However, the use of planktonic cells has potentially led to inconsistent results in infection outcomes. In this study, well-established biofilms of methicillin-resistant Staphylococcus aureus were grown and used as initial inocula in an animal model of a Type IIIB open fracture. The goal of the work was to establish, for the first time, a repeatable model of biofilm implant-related osteomyelitis, wherein biofilms were used as initial inocula to test combination biomaterials. Results showed that 100% of animals that were treated with biofilms developed osteomyelitis, whereas 0% of animals not treated with biofilm developed infection. The development of this experimental model may lead to an important shift in biofilm and biomaterials research by showing that when biofilms are used as initial inocula, they may provide additional insights into how biofilm-related infections in the clinic develop and how they can be treated with combination biomaterials to eradicate and/or prevent biofilm formation.

The effect of androgen deprivation on the early changes in prostate volume following transperineal ultrasound guided interstitial therapy for localized carcinoma of the prostate.

PURPOSE: To determine the change in volume of the prostate as a result of neoadjuvant androgen deprivation prior to prostate implant and in the early postimplant period following transperineal ultrasound guided palladium-103 brachytherapy for early-stage prostate cancer. METHODS AND MATERIALS: Sixty-nine men received 3 to 6 months of androgen deprivation therapy followed by treatment planning ultrasound followed 4 to 8 weeks later by palladium-103 implant of the prostate. All patients had clinical and radiographic stage T1c-T2b adenocarcinoma of the prostate. A second ultrasound study was carried out 11 to 13 days following the implant to determine the change in volume of the prostate as a result of the implant. The prehormonal and preimplant volumes were compared to the postimplant volume to determine the effect of hormones and brachytherapy on prostate volume. RESULTS: The median decrease in prostate volume as a result of androgen deprivation was 33% among the 54 patients with prostate volume determinations prior to hormonal therapy. The reduction in volume was greatest in the quartile of men with the largest initial gland volume (59%) and least in the quartile of men with smallest glands (10%). The median reduction in prostate volume between the treatment planning ultrasound and the follow-up study after implant was 3%, but 23 (33%) patients had an increase in prostate volume, including 16 (23%) who had an increase in volume >20%; 11 of these patients (16%) had an increase in volume >30%. The time course of development and resolution of this edema is not known. The severity of the edema was not related to initial or preimplant prostate volume or duration of hormonal therapy. CONCLUSIONS: Prostate edema may significantly affect the dose delivered to the prostate following transperineal ultrasound guided brachytherapy. The effect on the actual delivered dose will be greater when shorter lived isotopes are used. It remains to be observed whether this edema will affect outcome.

Improved treatment planning for the Syed-Neblett template using endorectal-coil magnetic resonance and intraoperative (laparotomy/laparoscopy) guidance: a new integrated technique for hysterectomized women with vaginal tumors.

The Syed template (Alpha-Omega Services, Bellflower, CA) represents an advance in interstitial gynecologic brachytherapy; however, its appeal is diminished by inaccuracies in target definition secondary to suboptimal imaging of gynecologic tumors and the risk of viscus perforation during a "blind" procedure. Magnetic resonance (MR) scanning with an endorectal coil and computed tomography were studied as a possible tool to improve target definition and maximize treatment planning with Syed templates. Abdominopelvic contents could be visualized directly through a laparotomy incision or indirectly with a laparoscopic video display to allow further target definition and minimize complications associated with blind procedures after hysterectomy. The synthesis of these techniques with Syed template applications was attempted to potentiate the utility of this brachytherapy system. Five patients with apical vaginal tumors which arose after previous hysterectomies (two endometrial cancer recurrences, one recurrent uterine sarcoma, two primary vaginal cancers) were referred for radiotherapy. In three cases, external beam pelvic radiotherapy (median dose, 45 Gy; range, 45-50.4 Gy) was delivered initially. In all cases, the Syed applicator was used for the brachytherapy component of the treatment. In two cases, high-resolution MR images (400 x 400 microns) of the vaginal apex were obtained after insertion of an endorectal surface coil. The images defined the relationships between the template, target volume, bladder, rectum, and intestine. The other three cases were planned with computerized tomography (CT). In all cases, intraoperative examination of the abdominopelvic contents was provided when laparotomy and/or laparoscopy was performed by the surgical team. The median brachytherapy dose prescribed to the isodose envelope covering the target volume was 40 Gy (range, 31-50 Gy). In all cases, the target volumes could be encompassed by the 60 cGy/hr isodose line. Tumor volume estimation was better with MR than CT. Procedure time was shorter with laparoscopy than with laparotomy. In two cases, bowel displacement was performed (one tissue expander, one omental sling) to prevent viscus perforation by interstitial needles. Four of five patients responded completely to the treatment. In three cases, local control was maintained at a median follow-up of 11 months. In conclusion, endorectal coil MRI may be advantageous to CT of the pelvis in that it allows preplanning to be achieved with greater precision and with less planning time. Major intraoperative complications (i.e., perforation of hollow viscus organs) can be avoided when the course of interstitial catheters is visualized from above by the surgical team.(ABSTRACT TRUNCATED AT 400 WORDS)

Contouring structures for 3-dimensional treatment planning.

Three-dimensional (3-D) treatment planning is a labor-intensive process with contouring of the target volume and critical normal tissues being a significant time-consuming component. The use of 3-D treatment planning on a routine basis may be limited by the time required to complete treatment plans. Despite the need to increase the efficiency of the process, there is little literature addressing the speed and accuracy of contouring systems. In an attempt to initiate systematic analysis of the contouring process, data sets consisting of 10 CT images each were developed on two patients with esophageal carcinoma. Nine different operators manually contoured structures (target volume, spinal canal, lungs) on the data sets using four different contouring systems present in our department. These included both commercially available systems and those developed by the authors. There was a wide variation in the hardware and software characteristics of these systems. The time required to contour the CT data sets was recorded and analyzed. The contouring accuracy was assessed by comparison with a standard template derived from the CT data set for each image. The contouring time was found to be dependent on the system design, previous contouring experience, and the type of drawing instrument (lightpen vs mouse). The mean contouring time ranged from 26 minutes per patient for the fastest system to 41 minutes for the slowest. Potential clinically significant errors in contouring were rare for the spinal canal and lungs but present at a greater rate for the target volume (30.3%). The implications of this finding are discussed.

Interinstitutional experience in verification of external photon dose calculations.

Under the auspices of NCI contracts, four institutions have collaborated to assess the accuracy of the pixel-based dose calculation methods they employ for external photon treatment planning. The approach relied on comparing calculations using each group's algorithm with measurements in phantoms of increasing complexity. The first set of measurements consisted of ionization chamber measurements in water phantoms in normally incident square fields, an elongated field, a wedged field, a blocked field, and an obliquely incident beam. The second group of measurements was carried out using thermoluminescent dosimeters in phantoms designed to investigate the effects of surface curvature, high density heterogeneities, and low density heterogeneities. The final study tested the entire treatment planning system, including CT data conversion, in an anthropomorphic phantom. Overall, good agreement between calculation and measurements was found for all algorithms. Regions in which discrepancies were observed are pointed out, areas for algorithm improvement are identified and the clinical import of algorithm accuracy is discussed.

Rapid, accurate, three-dimensional location of multiple sees in implant radiotherapy treatment planning.

The three-dimensional (3D) locations of the radioactive seeds in an interstitial implant can be obtained from stereo-shift or orthogonal radiographs. When an implant contains a large number of seeds, however, there are often ambiguities in identifying corresponding seed images on two radiographs. Our method achieves accurate spatial locations by using three radiographs whose x-ray source positions are (i) in a plane which does not intersect the implant and (ii) widely separated to achieve adequate parallax. All triangulation is done in an anatomical coordinate reference frame attached to the patient so that patient motion does not introduce errors. We achieve independent error-insensitive calibration of each radiograph, rapid and accurate data entry in the local coordinates of each radiograph, 3D seed location in the patient (anatomical) reference frame, and automatic verification of each calculation.