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The fragile X syndrome is caused by an unstable CGG repeat sequence in the 5' untranslated region of the X-linked, FMR1 gene. When the number of repeats exceeds 200, the region is hypermethylated and the gene is silenced. The lack of the protein produced by the FMR1 gene, FMRP, causes the fragile X syndrome. Recent evidence suggests that FMR1 alleles with unmethylated long repeat tracks (40-200 repeats) may cause a specific somatic phenotype in women, premature ovarian failure, and may cause variation in the levels of FMR1 mRNA and FMRP. Because FMR1 is known to be involved in the regulation of subset of genes expressed in the brain, we investigated the variation in cognitive and/or behavioral performance among carriers of high repeat alleles. Specifically, we administered cognitive, behavioral, and adaptive performance tests to children identified with high repeat alleles who attended special education classes in Atlanta, Georgia public schools and to those with < 40 repeats drawn from the same population. Overall, we found no significant effect of repeat size and the psychometric measures in our test battery after adjustment for multiple comparisons. All scales were found to be within 1 SD standard deviation of the mean. We did find an intriguing, albeit marginally statistically significant, association in the cognitive profile among males and not females, consistent with an X-linked effect. After adjusting for the overall cognitive abilities score, Verbal Ability scores decreased and Nonverbal Reasoning scores increased with repeat number to a greater extent in males than females. Spatial Ability scores were not associated with repeat number.

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Thirty-three hips in 23 patients (followed for 5.3 years) were treated with core decompression for early osteonecrosis of the femoral head (Ficat and Arlet I, IIA, IIB). When the clinical endpoint of severe pain was used for survivorship, 76% of hips survived 1 year, 52% survived 2 years, and 44% survived 5 years. When the radiographic endpoint of progression to stage III disease was used, no progression was found in 72% of hips at 1 year, 61% at 2 years, and 37% at 5 years. When total hip arthroplasty was used as an endpoint, 90% of hips survived 1 year, 70% survived 2 years, and 61% survived 5 years. Lower radiographic stage was associated with a better result. Patients who weighed less than 79.4 kg (175 lb.) (P = .03) or whose bone stock was good (femoral index < 0.56, P < .001) had significantly improved survival. Outcome evaluation documented a 70% overall patient satisfaction rate in patients not undergoing total hip arthroplasty.

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The treatment of the displaced intraarticular fracture of the os calcis continues to be controversial. One of the reasons for this is the lack of a workable classification system which would allow comparison among different treatment modalities. Plain radiographs are unable to depict the complex three-dimensional pathology of this fracture. Computed tomography (CT) scanning, however, has the potential to quite accurately depict all components of this injury. At our hospital, a five-part, CT-based classification system has been utilized. This system suggests which fractures will do well with conservative care, and which fractures are amenable to operative stabilization.

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Among authors over the past 35 years, medial tibial syndrome, or "shin splints," has been interpreted to mean many different things. We present a review of the literature to attempt to ascribe one definition to this clinical entity, and to clearly define its symptoms, signs, pathophysiology, biomechanics, and treatment. In addition, we describe our results with five patients whose seven affected limbs eventually required surgery for this condition, and we compare them to the results in the literature.

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This review focuses on the clinical history, diagnosis, and treatment of chronic exertional compartment syndrome (CECS) of the lower leg. Measurement of muscle compartment pressures, the most conclusive way to confirm the diagnosis, may yield significantly elevated values in CECS patients compared to normal controls. It is important to recognize that medial tibial syndrome is a distinct clinical entity from deep posterior CECS. Once a diagnosis of CECS is established, surgical decompression of the involved compartment is recommended. For as yet unknown reasons, the results of fasciotomy are almost always satisfactory in the anterior compartment and significantly less so in the posterior compartment.

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Using an in-shoe plantar pressure sensor, the pressure under the first metatarsophalangeal (MTP) joint was measured in 20 asymptomatic control subjects during their normal gait. A 7-micron in-shoe pressure sensor recorded the pressure under the first MTP joint in the 20 volunteers while they were wearing their normal footwear (athletic footwear), a wooden postoperative shoe, a fiberglass short leg walking cast, and a postoperative shoe with a first MTP joint cutout orthotic device. The results showed both casting, and the postoperative shoe with the first MTP joint cutout orthotic device significantly reduced pressure under the first MTP joint compared with normal footwear, with an average decrease of 31% and 43%, respectively. However, the standard postoperative shoe did not significantly reduce first MTP pressure compared with normal footwear. Certain surgeries performed on the distal first metatarsal may benefit from a diminution of loading forces encountered during normal gait. The results of this study indicate that a reduction of first MTP pressures can best be accomplished with either a postoperative shoe with a cutout orthotic device or a short leg walking cast. A standard postoperative shoe showed inconsistent results and had no statistically significant effect on decreasing the pressure under the first MTP joint.

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Teachers report using both reprimands and encouragement as strategies to reduce off-task behavior in the classroom. Although numerous studies have demonstrated the effectiveness of reprimands, none has examined the efficacy of encouragement. In order to answer this question, two experiments were performed. Subjects were 16 children with academic and/or behavioral problems who were assigned to one of two classes in a remedial summer program. Experiment I employed a reversal design in each class to compare either reprimands or encouragement with No-Feedback conditions. Reprimands proved superior to No Feedback in reducing off-task behavior, but Encouragement did not. In Experiment II Reprimands and Encouragement were directly compared to one another, with each class exposed to both conditions. Reprimands resulted in lower rates of off-task behavior and higher academic productivity than Encouragement.

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