Subscapularis sparing total shoulder arthroplasty through a superolateral approach: a radiographic study.

BACKGROUND: Most anatomic total shoulder arthroplasty (ATSA) techniques release and reattach the subscapularis tendon. The risk of failed healing is a widely recognized complication. The purpose of this study was to radiographically compare a traditional deltopectoral (DP) approach and a superolateral subscapularis sparing (SSS) technique through the rotator interval. METHODS: A single, independent, blinded, reviewer analyzed preoperative and postoperative radiographs of patients undergoing ATSA performed by a single surgeon. The reviewer assessed humeral head height, humeral head medial offset, humeral head diameter, head-neck angle, humeral head centering, and coracohumeral offset, and used the anatomic reconstruction index (ARI) to evaluate overall reconstruction quality. RESULTS: There were 70 SSS and 20 DP patients included. When comparing preoperative with postoperative differences, we found that there was no difference between groups in humeral head height (P = .19), humeral head medial offset (P = .38), and coracohumeral offset (P = .07). The DP group had a mean humeral head diameter oversizing of 1.4 mm, whereas the superolateral group had an undersizing of 2.8 mm (P < .001). The head-neck angle difference of the SSS approach was 2° greater than that found with the DP group (P < .001). The humeral head centering in the DP group was 7% displaced vs. 12% with the SSS group (P = .001) relative to the glenoid size. The ARI was 7.35 for the DP group and 6.93 for the SSS group (P = .50). DISCUSSION AND CONCLUSIONS: Radiographic comparison of these 2 ATSA techniques identified no statistical significant difference in 4 of 7 radiographic measurements and ARI. The SSS ATSA is a reasonable approach that yields similar radiographic measurements as a traditional DP total shoulder arthroplasty approach.

Subscapularis-Sparing Rotator Interval Approach for Anatomic Total Shoulder Arthroplasty.

BACKGROUND: A subscapularis-sparing approach to anatomic total shoulder arthroplasty (TSA) is used for patients with glenohumeral osteoarthritis who have an intact rotator cuff and sufficient bone volume. DESCRIPTION: A 7 to 10-cm anterosuperior incision is made with the patient in the beach chair position. The anterolateral deltoid muscle raphe is split, and the shoulder is externally rotated to bring the rotator interval to the field. A flap of interval tissue is incised, tenodesis of the biceps tendon is performed, and the interval tissue is incised straight back to the glenoid from the upper edge of the subscapularis, creating a triangular piece of tissue referred to as a "trapdoor." Two Darrach retractors are placed to expose the humeral head. An intramedullary guide is placed, and a humeral head osteotomy is performed. The glenoid is exposed, and the glenoid component is placed after sizing, preparation, drilling, and insertion of trial components per the surgical technique. The humeral head size is estimated by measuring, and the humeral stem size is decided by sequentially inserting the trial components. The permanent humeral stem is inserted, and the permanent humeral head is implanted after insertion of trial components. The trapdoor is sutured, the deltoid is reattached, and subcutaneous tissue and skin are sutured. ALTERNATIVES: The traditional surgical approach for anatomic TSA involves release and reattachment of the subscapularis tendon. RATIONALE: Nearly all anatomic TSA techniques require the subscapularis to be released, with a peel, tenotomy, or osteotomy, and then repaired on completion of the arthroplasty. Failure of the subscapularis to heal is an unfortunate and potentially devastating complication following anatomic TSA that has been linked to decreased function, instability, and pain1-4. Subscapularis dysfunction following anatomic TSA is seen in one-third to two-thirds of patients, with evidence of complete tears in up to 50% of asymptomatic patients using ultrasound examinations1-5.Sling immobilization with avoidance of excessive passive external rotation and active internal rotation is recommended to help prevent postoperative rupture of the subscapularis repair6-8. However, postoperative motion restrictions to protect the subscapularis may lead to stiffness and may negatively impact function and satisfaction.We describe a subscapularis-sparing TSA, in which we address and improve on 3 technical difficulties identified by Lafosse et al.9: (1) difficulty ensuring an anatomic humeral neck cut because of the difficulty visualizing the anterior aspect of the shoulder, (2) inadequate resection of inferior humeral neck osteophytes, and (3) undersizing of the humeral head.

Adult age differences in memory for distinctive information: evidence from the bizarreness effect.

Two experiments examined age-related differences in memory for bizarre and common pictures. In Experiment 1, a facilitative effect of bizarreness was obtained for young adults and one of the older groups, but not for the oldest group (over age 70). However, the bizarreness effect was found for even the oldest group when predominantly common lists were used in Experiment 2. It is concluded that older adults suffer from deficits in distinctive processing, but those deficits can be reduced by providing a more uniformly common context in which differences can be processed.

Relationships between personality variables and bizarreness effects in free recall.

Relationships between 6 personality variables and each of 3 different measures of recall for bizarre and common sentences were examined. The personality variables investigated included measures of sensation seeking, novelty experiencing, desire for novelty, arousal-seeking tendency, social potency, and conservatism. Recall was measured in terms of sentences accessed, target words recovered per accessed sentence, and misplaced target words. The results indicated the typical pattern of bizarreness effects on recall and significant relationships between personality variables and these effects. Arousal seeking and conservatism were positively related to a bizarreness advantage in sentences accessed. Additionally, high social potency was related to the recovery of more details from common than bizarre sentences, and high desire for novelty was related to a greater bizarre misplacement effect. The results are discussed in terms of orienting and defensive responses to bizarreness.

Humour mediates the facilitative effect of bizarreness in delayed recall.

The first empirical study focused exclusively on the influence of bizarre elaboration on memory (Delin, 1968) indicated a significant relationship between bizarreness and recall after a 15-week delay. However, that study was strongly criticized on methodological grounds. The present study offers a conceptual replication of Delin's historically significant study which sought to verify his influential, yet criticized, results and to test the possibility that a humour response mediates the relationship between bizarre elaboration and recall using multiple regression procedures. In keeping with Delin's findings, the results of the present study suggest that bizarre elaboration facilitates both free and cued recall after a substantial delay. The results also suggest that the facilitative effects of bizarreness are mediated by humour. The findings are discussed in the context of a comprehensive theory of bizarreness effects.

The effect of exemplar activation on mental representations of the ingroup: the moderating role of relative ingroup size.

The current research explores the effects of exemplars on the stereotype representation of one's ingroup. Previous research demonstrated that exposure to an ingroup exemplar affects the stereotype one holds of one's ingroup (Coats & Smith, 1999). The primary purpose of the present study was to examine whether this effect is moderated by relative ingroup size. Participants were placed into either a minority or majority group situation and exposed to 1 of 2 dissimilar exemplars of their ingroup. Later, they rated their ingroup. Ratings of the ingroup differed between exemplar conditions in unexpected ways, indicating that the exemplar affected participants' stereotype of their ingroup. Furthermore, exemplars had a stronger effect on participants in the minority group than those in the majority group. Finally, relative ingroup size and, to a marginal extent, exemplars were found to affect ratings of ingroup variability.

Seroepidemiology of strongyloidiasis in the Peruvian Amazon.

A stool and serosurvey for Strongyloides stercoralis was conducted in a community in the Peruvian Amazon region. Strongyloidiasis stercoralis was identified in the stool of 69 (8.7%) of 792 participants. Six hundred nine sera were tested using by an enzyme-linked immunosorbent assay (ELISA), which had a sensitivity of 92% and a specificity of 94%; 442 (72%) were positive. In multivariable logistic regression models, having S. stercoralis in stool was associated with hookworm in the same specimen (odds ratio [OR] = 4.44, 95% confidence interval [CI] = 2.02-9.79), occasionally or never wearing shoes (OR = 1.89, 95% CI = 1.10-3.27), and increasing age (OR = 1.012 for each one-year increase, 95% CI = 1.00-1.03). Similarly, occasionally or never wearing shoes (OR = 1.54, 95% CI = 1.01-2.37) and increasing age (OR = 1.04 for each one-year increase, 95% CI = 1.02-1.06) were associated with an increased risk of a positive S. stercoralis ELISA result. The ELISA had a negative predictive value of 98% and is an excellent screening test for strongyloidiasis.

Memory for frequency of bizarre and common stimuli: limitations of the automaticity hypothesis.

In 2 experiments, the influence of intention to process frequency on accuracy of memory for frequency of bizarre and common sentences was investigated. The results from multiple regression analyses indicated that intentional processing increased the accuracy of frequency judgments when memory for frequency was tested after a 2-min (Experiment 1) and after a 48-hr (Experiment 2) retention interval. Furthermore, the results of Experiment 2 indicated that unintentional processors tended to overestimate frequencies of bizarre relative to common items after a delay. The implications of the results are discussed with regard to L. Hasher and R. T. Zacks's (1984) automaticity hypothesis, human performance, and the accuracy of judgments of frequency of occurrence of unusual events.

Free recall accuracy for common and bizarre verbal information.

A large body of empirical research suggests better free recall for bizarre than common verbal information; however, the bulk of those studies used a method that does not consider the contextual and relational accuracy of recovered memories. The conclusions drawn from that research therefore are based on tests of memory not for holistic stimuli but for decontextualized memory fragments. In response to this anomaly and recent findings suggesting that bizarre memories are more likely to be distorted than common memories, a holistic analysis of free recall for common and bizarre verbal material was conducted. Two experiments indicated that bizarreness both facilitates and disrupts recall. Specifically, better recall (both in part and in full) was found for bizarre information, but a greater tendency to merge bizarre memory fragments into other partially recovered memories was also found. This pattern of results was demonstrated under immediate and delayed testing conditions (Experiment 1) and using both incidental and intentional learning procedures (Experiment 2). Overall, the results are consistent with a weak account of disruption caused by bizarreness.

Test of competing explanations of the bizarre response bias in recognition memory.

Recent research has demonstrated that a more liberal response criterion is used when people make judgments about bizarre items than about common items in old-new tests of recognition. The present study was designed to test 2 possible explanations of the bizarre response bias. The bizarre-relations explanation suggests that the bizarre response bias is triggered by the bizarre relations depicted in test items. The target-constituent explanation suggests that the bizarre response bias is the result of a sense of familiarity with constituents of bizarre test items. These explanations were tested by examining the influence of lure manipulations on memory discrimination and response bias for common and bizarre hand-drawn pictures. The results indicated support for the target-constituent explanation by reversing the response bias (obtaining a common response bias) in a recognition test that used common lures containing constituents from bizarre target items and bizarre lures containing constituents from common target items. The results also indicated that increased verbal elaboration enhanced memory discrimination and reduced response bias for both common and bizarre stimuli. The implications of these results are discussed with regard to the false memory controversy.

Proximity attitudes toward objects and people: reference to a category and a self-representation?

The relative strength of similarity to self and category typicality as predictors of proximity attitudes (social distance) toward people of varying race and objects associated with people of varying race was investigated. Similarity to self and category typicality were significant predictors of proximity attitudes toward both objects and people, but similarity to self was the significantly stronger predictor. The predictive utility of similarity to self was greater for object judgments than person judgments, but category typicality was a better predictor of person judgments than object judgments. Although the results provide evidence of ingroup favoritism in proximity attitudes toward people, the ingroup bias did not extend to objects associated with people. Category typicality was positively related to attitudes, even for distanced groups. The role of predictability of the target in determining proximity attitudes is discussed.