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Internal fixation for fractures of the humeral capitellum is a technically challenging procedure. Controversy exists regarding the optimal surgical approach and fixation technique. The benefit of stable fixation of the capitellum fragment is early mobilization. Our preferred technique involves anatomic reduction of the capitellar fragment and fixation with headless screws placed from anterior to posterior. When possible, the surgical exposure employed preserves the lateral ulnar collateral ligament (LUCL) and minimizes disruption of the soft tissues posterior to the capitellum.

Purpose: As the practice of using high-energy photon beams to create therapeutic radiation fields of subcentimeter dimensions ͑as in intensity-modulated radiotherapy or stereotactic radiosurgery͒ grows, so too does the need for accurate verification of beam output at these small fields in which standard practices of dose verification break down. This study investigates small-field output factors measured using a small plastic scintillation detector ͑PSD͒, as well as a 0.01 cm 3 ionization chamber. Specifically, output factors were measured with both detectors using small fields that were defined by either the X-Y collimator jaws or the multileaf collimator ͑MLC͒. Methods: A PSD of 0.5 mm diameter and 2 mm length was irradiated with 6 and 18 MV linac beams. The PSD was positioned vertically at a source-to-axis distance of 100 cm, at 10 cm depth in a water phantom, and irradiated with fields ranging in size from 0.5ϫ 0.5 to 10ϫ 10 cm 2 . The field sizes were defined either by the collimator jaws alone or by a MLC alone. The MLC fields were constructed in two ways: with the closed leaves ͑i.e., those leaves that were not opened to define the square field͒ meeting at either the field center line or at a 4 cm offset from the center line. Scintillation light was recorded using a CCD camera and an estimation of error in the medianfiltered signals was made using the bootstrapping technique. Measurements were made using a CC01 ionization chamber under conditions identical to those used for the PSD. Results: Output factors measured by the PSD showed close agreement with those measured using the ionization chamber for field sizes of 2.0ϫ 2.0 cm 2 and above. At smaller field sizes, the PSD obtained output factors as much as 15% higher than those found using the ionization chamber by 0.6ϫ 0.6 cm 2 jaw-defined fields. Output factors measured with no offset of the closed MLC leaves were as much as 20% higher than those measured using a 4 cm leaf offset. Conclusions:The authors' results suggest that PSDs provide a useful and possibly superior alternative to existing dosimetry systems for small fields, as they are inherently less susceptible to volume-averaging and perturbation effects than larger, air-filled ionization chambers. Therefore, PSDs may provide more accurate small-field output factor determination, regardless of the collimation mechanism.

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Between 1987 and 1992, 30 infants aged 1.4–13 months (mean 7.3 months) underwent unilateral lambdoid strip craniectomy at the Children’s Hospital of Buffalo for occipital plagiocephaly. Males outnumbered females (22:8) and right-sided occipital flattening was significantly more common than left-sided flattening (25:5). The deformity was noticed at an average age of 3.2 months; 16% of the infants had an asymmetry at birth. Positional preferences (a distinct tendency to lie preferentially on the back, in most cases with the head turned to the ipsilateral side) were described in 79% of infants for whom this information was available, and torticollis was present in 10%. Pre- and postoperative CT scans were analyzed using several morphometric measurements. Asymmetries were measured between the flattened and contralateral sides, both posteriorly and anteriorly, using a translucent grid placed over the CT slice showing maximum asymmetry. The average maximum asymmetry between the flattened and contralateral sides was 24% posteriorly and 16% anteriorly. Significant improvements were seen postoperatively, with both anterior and posterior asymmetries improving by an average of one third (p < 0.05). However, when compared with CT scans from a control group of infants without synostosis, the operated group showed persistent and significant asymmetries postoperatively. The morphometric measurements described allow an objective and reproducible means of assessing the results of various treatments for this disorder. The improvements following unilateral lambdoid craniectomy are difficult to interpret in isolation; we suggest that future efforts be directed toward similarly assessing the results of both nonoperative treatments such as positional changes and molding helmets, and more aggressive surgical treatments that have been advocated for this disorder.

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