Anterior Research Articles

All Movements are Not Created Equal in the Course of Prostate Cancer Treatment

Purpose/Objective: IGRT technology can be used to correct for prostate motion which, based on data from multiple studies, can be as much as 2 cm. Both deformation and dislocation of the prostate can occur, with target day-to-day dislocation having the dominant effect. The same amount of movement may create different degradation of planning target volume (PTV) coverage for different movement directions when patients are treated with IMRT. This study quantifies dosimetric deviations for prostate movements in individual directions. Materials/Methods: A total of 10 prostate cases with the GTV ranging from 15 cc to 100 cc were selected for this study. IMRT plans that have 95% of the PTV (1 cm uniform margin from GTV) volume covered by the prescription dose of 75.6 Gy were generated. The dose objectives for the rectum and bladder were that less than 20% of each volume would receive more than 65 Gy. Eight gantry directions were used. Two IMRT plans using collimator angles 0o and 90o were generated to study the effect of different intensity distribution. To simulate prostate shifts, virtual systematic movements of the targets of 3 mm, 5 mm and 10 mm were introduced in the anterior (ANT), posterior (POST), superior (SUP), inferior (INF), left (LT) and right (RT) directions. The same IMRT plans were applied to the displaced targets. Dosimetric analysis was performed for the PTV coverage before and after the displacement. Results: For patients whose GTV was relatively small (<20 cc), a 3 mm displacement created the same amount of PTV coverage degradation as 5 mm displacement for larger GTVs (table 1): movement in the LT or RT direction brought 1–2% decrease in the volume covered; for ANT movement, PTV coverage fell 1–3%, POST: 3–16%; the SUP/INF movement decreased the volume covered by 1–10%. For a 10 mm displacement the degradation of PTV coverage are 3–20%, 3–20%, 4–18%, 12–27%, 3–24% and 4–24% for LT, RT, ANT, POST, SUP and INF directions respectively. From table 1, LT and RT movements caused similar dosimetric effects. Same amount of movement in POST direction may cause significantly more degradation of PTV coverage than in the ANT direction. This observation was most likely explained by the difference in the target shape ANT and POST. The effect from the same amount of INF or SUP movement varied, from causing identical effect to having significant difference (up to 10% deviation in PTV coverage). Some of the differences were caused by the different intensity distribution in either direction. When the lighter intensity pattern (lower fluence) was at the SUP edge and darker pattern (higher fluence) was along the INF edge, the same amount of movement in INF direction caused very little PTV coverage degradation while the superior movement may cause significant degradation. Conclusions: The relative dosimetric impact of target movement depends not only on the amount of movement, but also on the movement direction, individual target characteristic and IMRT treatment plan parameters. The target motion has to be evaluated in the context of dose variation. When we set action levels for IGRT, we have to consider not just the amount of the movement, but all the other parameters that affect the treatment delivery quality. Tabled 1

Nasal Airway Dimensions of Adults with Cleft Lip and Palate: Differences among Cleft Types

To determine the nasal airway dimensions in adults with repaired cleft lip and palate by rhinomanometry and to analyze the reduction associated with different types of clefts. A prospective analysis comparing three types of previously repaired clefts: bilateral cleft lip and palate (BCLP), unilateral cleft lip and palate (UCLP), and isolated cleft palate (CP) at the 5% level of significance. Laboratory of Physiology, Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo, Bauru, Brazil. Fifty-three subjects aged 18 to 35 years (17 BCLP, 16 UCLP, 20 CP) and a group of 20 individuals without cleft (N). Minimum cross-sectional nasal area assessed by posterior (PR) and anterior (AR) rhinomanometry and nasopharyngeal area assessed by modified AR. Mean (+/- 1 SD) nasal areas obtained by PR were: 0.47 +/- 0.16 cm(2) (BCLP), 0.57 +/- 0.19 cm(2) (UCLP), 0.61 +/- 0.13 cm(2) (CP), and 0.60 +/- 0.10 cm(2) (N). The mean value for the BCLP group was significantly smaller than that for the N and CP groups. The remaining values did not differ from one another. The proportion of subjects with subnormal areas obtained by PR was 41%, 19%, and 0% for groups BCLP, UCLP, and CP, respectively. Similar results were obtained by AR. All subjects presented a nasopharyngeal area larger than 0.80 cm(2), denoting absence of obstruction in the nasopharynx. In adulthood BCLP is the type of cleft associated with a greater reduction of nasal airway, compared with UCLP and CP, suggesting that adults with BCLP are at a greater risk for nasal obstruction.

The experimental study on trypan blue in staining rabbit's anterior capsule

目的 研究台盼蓝晶状体前囊染色的效果和安全性.方法健康日本大耳白兔24只,分为台盼蓝染色组和空白对照组;每只兔左右眼分别采用直接染色法(A组)及气泡下染色法(B组).观察角膜内皮、眼前段、眼压变化及不同时期病理和超微病理表现.结果A组角膜内皮轻度着色,晶状体前囊着色,虹膜浅着色;B组晶状体前囊着色.术前、术后1、3、7日角膜内皮细胞计数、内皮细胞变异系数、六角形细胞比例及眼压变化差异均无显著意义(P＞0.05).各组病理切片角膜内皮细胞均见不同程度核异形及水肿.扫描电镜显示术后1日 B组角膜内皮细胞肿胀轻于A组.结论0.1%台盼蓝可使兔眼晶状体前囊着色,眼内应用安全有效.气泡下染色效果更好。

Comportamento dos empresários islâmicos em Moçambique

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Analysis of Diaphragmatic Motion with Prone Positioning Using Dynamic MRI

The objective of this study was to quantitatively analyze differences in diaphragmatic motion between supine and prone positioning during resting breathing using dynamic Magnetic Resonance Imaging. Total diaphragmatic motion (TDM), defined as total excursion of the anterior (ANT), central (CNT), and posterior (PST) diaphragm, was 61 mm in the supine position and 63 mm in the prone position. No significant difference in TDM was apparent in response to change in positioning. Diaphragmatic motion was greatest in the PST > CNT > ANT with supine positioning, and PST > ANT ∼ CNT with prone positioning. In both positions, motion tended to be greatest in the posterior diaphragm. However, relative changes in CNT and PST were less with prone than with supine positioning. These findings suggest that ventilation in the posterior lung fields is decreased to a greater extent with prone than with supine positioning.

Avaliação biomecânica dos tendões dos músculos tibiais e proposta de sua utilização como aloenxertos nas reconstruções do ligamento cruzado anterior

Com o objetivo de avaliar as propriedades mecânicas dos tendões dos músculos tibial anterior (TA) e tibial posterior (TP), o autor realizou ensaios mecânicos com tendões extraídos de 18 cadáveres humanos frescos, do sexo masculino, com média de idade de 45,2 ± 10,7 anos. Os tendões foram divididos em dois grupos e armazenados a -20°C e a -86°C durante 30 a 90 dias antes dos testes. Depois de descongelados, foram feitas medidas da área de secção transversa dos tendões e ensaios mecânicos de tração até a ruptura a uma velocidade de aplicação de carga de 20 mm/min. Foram determinadas as seguintes propriedades biomecânicas: resistência máxima, coeficiente de rigidez, módulo de elasticidade e alongamento máximo relativo; os dados obtidos foram comparados aos existentes na literatura relativos ao ligamento cruzado anterior (LCA) e seus substitutos mais utilizados. A comparação dos dados obtidos neste estudo com os estudos biomecânicos feitos por outros autores nos permitiu observar que o TA e o TP apresentam propriedades mecânicas que os tornam possíveis substitutos do LCA nos casos em que a necessidade de enxertos alógenos se impuser.

Imaging cortical association tracts in the human brain using diffusion‐tensor‐based axonal tracking

Diffusion-tensor fiber tracking was used to identify the cores of several long-association fibers, including the anterior (ATR) and posterior (PTR) thalamic radiations, and the uncinate (UNC), superior longitudinal (SLF), inferior longitudinal (ILF), and inferior fronto-occipital (IFO) fasciculi. Tracking results were compared to existing anatomical knowledge, and showed good qualitative agreement. Guidelines were developed to reproducibly track these fibers in vivo. The interindividual variability of these reconstructions was assessed in a common spatial reference frame (Talairach space) using probabilistic mapping. As a first illustration of this technical capability, a reduction in brain connectivity in a patient with a childhood neurodegenerative disease (X-linked adrenoleukodystrophy) was demonstrated.

THE CORRELATION OF TIBIAL GEOMETRIC DIMENSIONS WITH TIBIAL STRESS REACTIONS

Tibial bone stress reactions are a commonly occurring source of exertional lower limb pain amongst the active population, in particular runners and the military. MR imaging has been shown to demonstrate the continuum of bone stress reactions from marrow oedema, periosteal oedema, to stress fracture. Why these reactions occur predominantly along the postero-medial border and mid to distal tibia remain unclear. The purpose of this investigation was to study tibial cross-sectional geometry at 5 sites along the tibial diaphysis and at the sites of stress reaction. Results were analysed to determine any links with-in subjects between legs, site of stress reaction, geometry and then between males and females. Subjects for this prospective observational study were all active with pain of less than 3 months duration, 14 were male (1control) and 11 female (4 controls). Axial T1 weighted images where used to take cortical measurements of antero-posterior (AP), medio-lateral (ML) widths and the anterior (ANT), postero-medial (PM) and posterolateral (PL) corners. FSE-IR images were used to locate bone stress reactions and their geometry was measured. Observations of tibial shape and that of the site of stress reaction was made. RESULTS: The AP and ML diameters are narrowest in the mid to mid-distal tibia (P = 0.0001). Here the tibial axial shape is at its most triangular and the PM and PL corner widths largest. This same mid to mid-distal area of the tibia, where the area moment of inertia is increased, was the site for 73% of stress reactions. The stress reactions involved marrow oedema and periosteal fluid along the medial border extending to the PM corner. Endosteal oedema and signs of endosteal buttressing at the PM corner were also demonstrated. SUMMARY: Cross-sectional geometry and shape influences the site of stress reaction. In response to stress, the tibia compensates by increasing the width of the PM and PL corners through buttressing. A further longitudinal study is required to determine whether measureable tibial geometry is predicted of bone stress injury.

Pathologic changes associated with shoulder dislocations. Arthroscopic and physical examination findings in first-time, traumatic anterior dislocations.

This prospective observational study was performed on young patients, less than 24 years old, with first-time, traumatic anterior shoulder dislocations. These patients were offered either arthroscopic or nonoperative treatment. Fifty-three patients chose nonoperative treatment. Sixty-three patients elected to have arthroscopic procedures. The average patient age was 19.6 years. There were 59 men and 4 women. All procedures were performed within 10 days of dislocation. All 63 patients had hemarthrosis. Sixty-one of 63 (97%) patients treated surgically had complete detachment of the capsuloligamentous complex from the glenoid rim and neck (Perthes-Bankart lesion), with no gross evidence of intracapsular injury. Of the other two patients, one had an avulsion of the inferior glenohumeral ligament from the neck of the humerus, and one had an interstitial capsular tear adjacent to the intact glenoid labrum. Fifty-seven patients had Hill-Sachs lesions; none were large. There were six superior labral anterior posterior lesions, two with detachment of the biceps tendon. There were no rotator cuff tears. Of the 53 nonoperatively treated patients, 48 (90%) have developed recurrent instability. In this population, the capsulolabral avulsion appeared to be the primary gross pathologic lesion after a first-time dislocation. These findings, associated with the 90% nonoperative recurrence rate, suggest a strong association between recurrent instability and the Perthes-Bankart lesion in this population.

Arthroscopic treatment of partial rotator cuff tears in young athletes. A preliminary report.

Forty-three athletes under age 40, more than half of which were collegiate or professional, with partial rotator cuff tears were treated arthroscopically and observed for a minimum of 24 months. By history and mechanism of injury, two main groups were identified. Group A had 14 patients with acute, traumatic injuries. All 14 had inflamed subacromial bursas, but increased glenohumeral translation and labral lesions were uncommon. Twelve patients (86%) had satisfactory postoperative results and nine (64%) returned to preinjury sports after arthroscopic subacromial decompression and tear debridement. Group B had 29 overhead athletes with insidious, atraumatic shoulder pain. They were not as successful with debridement (19 [66%] satisfactory and 13 [45%] return to preinjury sports). Within Group B, three subgroups were identified based on the examination under anesthesia and subacromial inflammation. Group B1 (8 patients) had normal-appearing subacromial spaces and often increased anterior glenohumeral translation with posterior labral tears. These patients did poorly after arthroscopic tear debridement (3 [38%] satisfactory and 2 [25%] return to sports). Group B2 (12 patients) had inflamed subacromial bursas and increased glenohumeral translation. This group had marginal results with debridement (7 [58%] satisfactory and 6 [50%] return to sports). Group B3 (9 patients) with subacromial inflammation, yet without increased glenohumeral translation, had excellent pain relief (100%) but less than half (4) returned to preinjury sports.

Intercondylar notch width and its relation to the configuration and cross-sectional area of the anterior cruciate ligament. A cadaveric knee study.

If a narrow intercondylar notch contains a smaller anterior cruciate ligament, that may explain why people with narrow notches have a higher incidence of anterior cruciate ligament injuries. To investigate the significance of notch width measurement, we used 16 embalmed cadaveric knees. A positive mold of the entire anterior cruciate ligament, including its femoral and tibial insertions, was created with silicone rubber and plaster commonly used for dental molding. We had two hypotheses to test from this study. One was that the dimensions of the anterior cruciate ligament can be predicted by the notch width. The other was that the size of a person's anterior cruciate ligament can be predicted by a caliper measurement of the intercondylar notch. The width, sagittal length, and cross-sectional area of the midsubstance and the femoral and tibial insertions of the anterior cruciate ligament were measured. The notch width index, the ratio of notch width to width of the femoral condyle, showed a positive correlation only to the ratio of width to sagittal length of the tibial insertion. None of the parameters showed any differences between the knees with a notch width index less than or equal to 0.2 and those with a notch width index greater than 0.2. The knees with small notch width indexes did not have thinner anterior cruciate ligaments in them. These findings may not be applicable to knees obtained from other races, i.e., not Japanese.

Differences in friction and torsional resistance in athletic shoe-turf surface interfaces.

This study evaluated the shoe-surface interaction of 15 football shoes made by 3 manufacturers in both anterior translation and rotation using a specially designed pneumatic testing system. The shoes included traditional cleated football shoes, "court" shoes (basketball-style shoes), molded-cleat shoes, and turf shoes. Under an 11.35-kg (25-pound) axial load, all shoes were tested on synthetic turf under wet and dry conditions and on natural stadium grass. Test-retest reliability, as calculated using the Pearson Product-Moment Correlation test, was 0.85 for force of translation and 0.55 for the moment of rotation. The wet versus dry surface values on translation were significantly different for rotation about the tibial axis. Spatting, which is protective taping of the ankle and heel applied on the outside of the shoe, resulted in a reduction of forces generated in both translation and rotation. No overall difference between shoes on grass versus AstroTurf was noted. However, there were significant differences for cleated and turf shoes. Shoes tested in conditions for which they were not designed exhibited reproducible excessive or extreme minimal friction characteristics that may have safety implications. On the basis of this study, we urge shoe manufacturers to display suggested indications and playing surface conditions for which their shoes are recommended.

Effect of resistance training volume on strength and muscle thickness.

The purpose of this study was to determine the effects of different volumes of high-intensity resistance training on isometric torque and muscle thickness. Training was conducted three times per week using one set (low volume, EX-1, N = 18) or three sets (high volume, EX-3, N = 20) of dynamic variable resistance exercise. Ten subjects acted as nontraining controls (CONT). Bilateral knee extension (KEXT) and flexion (KFLEX) exercise was performed to fatigue within 8-12 repetitions for 14 wk. Maximal isometric KEXT and KFLEX torque was tested at 6 degrees, 24 degrees, 42 degrees, 60 degrees, 78 degrees, 96 degrees, and 108 degrees of KFLEX using a MedX (Ocala, FL) KEXT/KFLEX ergometer. The anterior (ANT), lateral (LAT), and posterior (POST) right thigh, the medialis muscle (MED), and the lateralis muscle (LATER) were assessed for thickness by B-mode ultrasound (ULTRA). Both training groups improved torque output at most angles, but there was no difference between EX-1 and EX-3 (P > or = 0.05). ULTRA detected increases in muscle thickness for EX-1 at 60% LAT and 40% and 60% POST. EX-3 increased muscle thickness at the MED, and 40% and 60% POST. In conclusion, one set of high intensity resistance training was as effective as three sets for increasing KEXT and KFLEX isometric torque and muscle thickness in previously untrained adults.

The effects of muscle fatigue on neuromuscular function and anterior tibial translation in healthy knees.

We investigated the effect of quadriceps and hamstring muscle fatigue on anterior tibial translation and muscle reaction time in 10 healthy subjects. The six men and four women had an average age of 21.3 years and had no known pathologic knee conditions. Each patient underwent a knee examination, arthrometer measurements of tibial translation, subjective functional assessment, and an anterior tibial translation stress test before and after quadriceps and hamstring muscle-fatiguing exercise. The recruitment order of the lower extremity muscles in response to anterior tibial translation did not change with muscle fatigue. However, the results showed an average increase of 32.5% in anterior tibial translation (range, 11.4% to 85.2%) after fatigue. Muscle responses in the gastrocnemius, hamstring, and quadriceps originating at the spinal cord and cortical level showed significant slowing and, in some cases, an absence of activity after the quadriceps and hamstring muscles were fatigued. The increases in displacement after fatigue strongly correlated (0.62 to 0.96) with a delay in cortical-level activity (intermediate and voluntary). Muscle fatigue, which appears to affect the dynamic stability of the knee, alters the neuromuscular response to anterior tibial translation. Therefore, fatigue may play an important role in the pathomechanics of knee injuries in physically demanding sports.

The relationship between tunnel placement and clinical results after anterior cruciate ligament reconstruction.

To correlate clinical results after anterior cruciate ligament reconstruction with tunnel placement measured radiographically, we prospectively studied 128 patients who had arthroscopically assisted bone-patellar tendon-bone reconstructions. Patients with bilateral anterior cruciate ligament reconstructions, other significant knee ligament injuries, or those undergoing chondroplasty or meniscal repairs were excluded, leaving 42 patients. The relationship between radiographic tunnel position and clinical results was determined using the Lysholm score, KT-1000 arthrometer testing, the Tegner activity level, and the pivot shift and Lachman tests. Clinical results correlated positively with posterior femoral tunnel placement on lateral radiographs and negatively with excessive anterior tibial tunnel placement. Specifically, when femoral tunnels were placed at least 60% posterior along Blumensaat's line and tibial tunnels were at least 20% posterior along the tibial plateau, 69% of patients had good or excellent Lysholm scores and 79% had KT-1000 arthrometer maximum manual side-to-side differences of 3 mm or less. When the above criteria were not met, 50% of patients had good or excellent Lysholm scores and 22% had KT-1000 arthrometer maximum manual side-to-side differences of 3 mm or less. This close correlation indicates that satisfactory radiographic tunnel position influences outcome after anterior cruciate ligament reconstruction.

Football cleat design and its effect on anterior cruciate ligament injuries. A three-year prospective study.

A 3-year prospective study was initiated to evaluate torsional resistance of modern football cleat designs and the incidence of surgically documented anterior cruciate ligament tears in high school football players wearing different cleat types. We compared four styles of football shoes and evaluated the incidence of anterior cruciate ligament tears among 3119 high school football players during the 1989 to 1991 competitive seasons. The four cleat designs were 1) Edge, longer irregular cleats placed at the peripheral margin of the sole with a number of smaller pointed cleats positioned interiorly (number of players wearing this shoe, 2231); 2) Flat, cleats on the forefoot are the same height, shape, and diameter, such as found on the soccer-style shoe (N = 832); 3) Screw-in, seven screw-in cleats of 0.5 inch height and 0.5 inch diameter (N = 46); and 4) Pivot disk, a 10-cm circular edge is on the sole of the forefoot, with one 0.5-inch cleat in the center (N = 10). The results showed that the Edge design produced significantly higher torsional resistance than the other designs (P < 0.05) and was associated with a significantly higher anterior cruciate ligament injury rate (0.017%) than the other three designs combined (0.005%).

Anterior cruciate ligament reconstruction as an outpatient procedure.

During a 27-month period, 222 patients with 227 anterior cruciate ligament-deficient knees underwent arthroscopically assisted reconstructions as outpatient procedures. Bone-tendon-bone autografts were used for 169 of these reconstructions; the other 58 were done with bone-tendon-bone allografts. Additional procedures were performed on 180 of the patients. The interval from injury to reconstruction averaged 29 months. The protocol developed at our clinic employs a general anesthetic administered with the intent of same-day discharge, infiltration of the skin and joint with bupivacaine, a cold compressive dressing, and the use of both ketorolac tromethamine and a Schedule III narcotic (acetaminophen with codeine or with propoxyphene) for postoperative pain control. At an average followup of 10 months, no readmissions in the immediate postoperative period had been required and no short- or long-term postoperative complications could be attributed to the protocol. This safe and effective technique offers the patient the advantage of anterior cruciate ligament reconstruction as a same-day procedure and allows the surgeon to implement its use in any outpatient setting without additional discharge planning.

Recurrent acromial bone spur after open subacromial decompression

Anter ior acromioplasty for the treatment of impingement syndrome in the shoulder is reportedly among the most widely used and successful operations in the field of orthopaedics. The original procedure, as popularized by Neer, 13 has enjoyed excellent clinical results with good success and few complications. 1' 3-r lo. 11, 13. 14 Since Neer's description was published in 1972, outcome studies have focused on clinical results. In fact, in those 22 years no study has reported a bony recurrence of the acromial spur. The question remains as to whether the subacromial decompression obtained by anterior acromioplasty persists in long-term follow-up. Most of these investigators rarely obtained postoperative radiographs, and few performed follow-up evaluations of their patients for more than 4 years. We report the case of a particularly impressive recurrence of a spur 5.2 years after open acromioplasty, perhaps raising suspicions about the longterm effectiveness of the anterior acromioplasty procedure.

PC 23 Microleakage of super EBA with and without finishing

I Microleakage of Super EBA With and Without Finishing. C-L. Hahn, M. Hauser*, R. N. Dodds, VCU/MCV, Richmond, VA. Super EBA (EBA) has been used as an alternative root-end filling material due to its superior sealability and clinical success. The purpose of this s tudy was to evaluate whether finishing EBA after it had set affected the apical seal. Sixty extracted maxillary anter ior teeth were ins t rumented to W[ with at least #60 MAF. Canals were ob tura ted wit] gutta percha prior to root-end resection. A 3 mm deep root -end prepara t ion was per formed on each tooth with ultrasonic tips. Teeth were then randomly divided into 3 groups of 20. Group I received EBA and finishing t reatment with a highspeed finishing bur. Group II received EBA without finishing treatment. Group HI received TERM root-end filling material as a control. Microleakage (ul /min) was measured under 10 psi with a fluid filtration method at day 1, 7, 30 and 90. Multivariate analysis with repeated measures was used to analyze data. Minimal leakage was observed in group HI. There was a significant increase of leakage with time in both EBA groups (p<O.01). There was no statistically significant difference between group I and II. Suppor ted b y Alexander Fellowship, MCV, School of Dentistry.

Nonoperative treatment of acute anterior cruciate ligament injuries in a selected group of patients.

Conservative treatment of acute anterior cruciate ligament injuries was recommended to selected patients, including those with sedentary occupations, low athletic demands, or ages greater than 30 years. Patients with generalized hyperligamentous laxity were excluded. Fifty-five of 61 patients were available at an average followup of 46 months from the time of initial injury. At followup, giving-way symptoms had not occurred in 23 patients (42%); in 22 (40%) giving way occurred occasionally. Of the 44 patients involved in high- or moderate-demand athletics, 33 (70%) were able to continue with moderate-demand sports. Presence of a medial collateral ligament sprain did not affect the longterm function. Forty-eight percent of the patients scored excellent or good (9 and 18 patients, respectively) on the Hospital for Special Surgery ligament scoring system; 8 (15%) later chose surgical reconstruction. The remaining 47 patients did not believe that their symptoms were severe enough to warrant any further intervention. In a group of individuals who are older and relatively inactive, nonoperative management of anterior cruciate ligament injuries can yield satisfactory results, provided the patients are willing to accept a modest amount of instability and a slight risk of meniscal injury.