Fluid-Signal Structures in the Cervical Spinal Cord on MRI: Anterior Median Fissure versus Central Canal.

BACKGROUND AND PURPOSE: Hyperintense fluid-signal anterior median fissure and hyperintense foci resembling the central canal are seen on cervical spine axial T2 MR imaging. They may also be associated with a channel-like T2-hyperintense craniocaudad line on sagittal images. We hypothesized that the hyperintense foci and the sagittal line may represent the base of the anterior median fissure. MATERIALS AND METHODS: In this exploratory study, 358 cervical MR images were analyzed for recording and comparing the incidence/numbers of hyperintense foci, anterior median fissure, and sagittal line as hyperintense foci, anterior median fissure, and sagittal line per patient when present alone or together, both with and without the sagittal line. RESULTS: Hyperintense foci were identified on 238/358 (66.5%) studies; an anterior median fissure, on 218/358 (60.9%). The hyperintense foci/anterior median fissure ratio was 3.7/2.3 (P = .00001). Anterior median fissures were seen alone less commonly than hyperintense foci were seen alone (P = .045). We identified increased anterior median fissure/patient in a hyperintense foci +anterior median fissure group compared with an anterior median fissure-only group (4.0 versus 3.2, P = .05), with similar hyperintense foci/patient in the hyperintense foci+anterior median fissure and hyperintense foci-only groups (5.5 versus 5.8, P = .35), and proportional distribution of both across the hyperintense foci+anterior median fissure subgroups (hyperintense foci/anterior median fissure ratio, 1.3). The sagittal line in 89 (24.9%) patients was associated with increased hyperintense foci and anterior median fissure/patient. Greater correlation of anterior median fissure/patient to sagittal line presence was seen in sagittal line subgroup analysis. CONCLUSIONS: This exploratory analysis found an increased anterior median fissure per patient in conjunction with hyperintense foci presence, a proportional increase of both across the hyperintense foci+anterior median fissure group, and greater correlation of anterior median fissure per patient with the sagittal line. These findings suggest that anterior median fissure and hyperintense foci are structurally related, that hyperintense foci may commonly be the base of the anterior median fissure, and that the sagittal line is a manifestation primarily of an anterior median fissure, occasionally appearing as channels that may simulate the central canal.

One-stage bilateral total joint arthroplasty: a prospective, comparative study of total hip and total knee replacement.

This prospective study compared the incidence of minor and major complications in 50 patients (100 joints) undergoing bilateral total knee arthroplasty (TKA) with 50 patients (100 joints) undergoing bilateral total hip arthroplasty (THA). Gender, comorbidities, American Society of Anesthesiologists scores, and body mass indices were similar in both groups. There was no difference in preoperative hemoglobin, operative time, anesthetic management, postoperative surveillance, and hemoglobin at discharge. However, the need for allogenic blood transfusion, despite preoperative autologous blood donation and retransfusion, was high for both groups (34% for bilateral TKA and 20% for bilateral THA. Bilateral THA patients had lower rates of total major and minor complications than bilateral TKA patients. Although cementless bilateral THA and cemented bilateral TKA can be performed efficiently and with relative safety in a select group of patients, the high rate of minor complications and in particular the need for allogenic transfusion in both groups is concerning and should be discussed with patients before surgery.

One-stage bilateral total hip arthroplasty compared with unilateral total hip arthroplasty: a prospective study.

It is believed that patients undergoing 1-stage bilateral joint arthroplasty are at higher risk for developing cardiopulmonary and possibly other complications. The aim of this prospective matched study was to evaluate and compare the morbidity profile of patients undergoing 1-stage bilateral uncemented total hip arthroplasty (BTHA) vs unilateral uncemented THA (UTHA). One hundred consecutive patients undergoing 1-stage bilateral THA (50 patients, 100 hips) and unilateral THA (50 patients) were recruited and prospectively followed. There were no statistically significant differences in 90-day mortality, individual major (BTHA, 8%; UTHA, 10%) or minor (BTHA, 20%; UTHA, 26%) complications between the 2 groups. Bilateral THA patients required more autologous and allogenic blood transfusion and had lower hemoglobin at discharge than UTHA patients. Patients undergoing BTHA should expect a slightly higher incidence of complications related to postoperative anemia.

The role of patient restrictions in reducing the prevalence of early dislocation following total hip arthroplasty. A randomized, prospective study.

BACKGROUND: It is currently unknown whether functional restrictions following total hip arthroplasty can reduce the prevalence of early postoperative dislocation. Our hypothesis was that dislocation was more likely to occur in patients who were not placed on these restrictions. METHODS: We performed a prospective, randomized study to evaluate the role of postoperative functional restrictions on the prevalence of dislocation following uncemented total hip arthroplasty through an anterolateral approach. Of the 630 eligible consecutive patients, 265 patients (303 hips) consented to be randomized into one of two groups (the "restricted" group or the "unrestricted" group). The patients in both groups were asked to limit the range of motion of the hip to <90 degrees of flexion and 45 degrees of external and internal rotation and to avoid adduction for the first six weeks after the procedure. The patients in the restricted group were instructed to comply with additional hip precautions during the first six weeks postoperatively. Specifically, these patients were managed with the placement of an abduction pillow in the operating room before bed transfer and used pillows to maintain abduction while in bed; used elevated toilet seats and elevated chairs in the hospital, in the rehabilitation facility, and at home; and were prevented from sleeping on the side, from driving, and from being a passenger in an automobile. All patients were followed for a minimum of six months postoperatively. RESULTS: There was one dislocation in the entire cohort (prevalence, 0.33%). This dislocation occurred in a patient in the restricted group during transfer from the operating table to a bed with an abduction pillow in place. Patients in the unrestricted group were found to return to side-sleeping sooner (p < 0.001), to ride in automobiles more often (p < 0.026), to drive automobiles more often (p < 0.001), to return to work sooner (p < 0.001), and to have a higher level of satisfaction with the pace of their recovery (p < 0.001) than those in the restricted group. There was an additional expenditure of approximately $655 per patient in the restricted group. CONCLUSIONS: Total hip arthroplasty through an anterolateral approach is likely to be associated with a low dislocation rate. Removal of several restrictions did not increase the prevalence of dislocation following primary hip arthroplasty at our institution. However, it did promote substantially lower costs and was associated with a higher level of patient satisfaction as patients achieved a faster return to daily functions in the early postoperative period.