Highly Porous Titanium Cups Frequently Presenting with Radiolucent Lines in Cementless Primary Total Hip Arthroplasty: A Retrospective Cohort Study.

Background/Objectives: A highly porous titanium cup with a three-dimensional metal interface was recently introduced to improve biological fixation and survival. However, radiography has revealed concerns regarding these cups, despite their excellent short- and mid-term clinical outcomes. This study compared the clinical and radiographic results of a highly porous titanium cup with those of a hydroxyapatite-coated porous titanium cup after primary total hip arthroplasty (THA). Methods: Fifty-one primary THAs were investigated. A highly porous titanium cup was used in 17 hips, and a hydroxyapatite-coated porous titanium cup was used in 34 hips. No significant differences in preoperative patient demographic characteristics were observed between the two groups. The 2-year postoperative clinical and radiographic results were compared. Results: Radiolucent lines were observed in 13 (76%) of 17 hips with highly porous titanium cups and in none (0%) of 34 hips with hydroxyapatite-coated porous titanium cups (p < 0.001). In the highly porous titanium cup group, radiolucent lines were observed in five hips (29%) in one zone, two hips (11%) in two zones, and six hips (35%) in three zones. No cup loosening was observed in either group. Conclusions: Radiolucent lines were significantly more frequent in highly porous titanium cups. This study suggests that, compared to the three-dimensional structure of porous titanium, the hydroxyapatite coating of porous titanium had a greater influence on bone ingrowth in the short term. The meaning of these findings in the long-term is unclear yet.

Efficacy of Early Rehabilitation for Severe Coronavirus Disease 2019 Pneumonia: Factor Analysis Using Machine Learning.

Objectives: Patients with severe coronavirus disease 2019 (COVID-19) who develop pneumonia face the risk of ventilatory muscle disuse in the acute phase, which can result in persistent respiratory impairments in the subacute phase. Although rehabilitation during the acute phase is considered effective, there are limited reports on this topic. Therefore, this study aimed to investigate the effectiveness of acute-phase rehabilitation in patients with severe COVID-19. Methods: The study included 57 patients (45 men and 12 women; mean age: 63.2±12.1 years) admitted between April and June 2021, all of whom required intubation for respiratory management. Among them, 34 patients underwent acute-phase rehabilitation interventions based on the early goal-directed mobilization protocol. The primary objectives were to assess the occurrence of medical accidents related to acute-phase rehabilitation and evaluate their impact on survival and mobility upon hospital discharge. Statistical techniques and machine learning algorithms were employed for data analysis. Results: Remarkably, no medical accidents occurred during the acute-phase rehabilitation among the patients. Furthermore, our findings indicated that acute-phase rehabilitation did not influence survival outcomes. However, it did have a positive impact on the mobility of patients upon hospital discharge. Conclusions: Acute-phase rehabilitation can be safely administered to patients with severe COVID-19 by following an early goal-directed mobilization protocol. This approach may also contribute to improved activities of daily living after discharge.

Is the Anterolateral or Posterolateral Approach More Effective for Early Postoperative Recovery after Minimally Invasive Total Hip Arthroplasty?

Currently, various minimally invasive surgical techniques are applied for total hip arthroplasty (THA). There are few studies comparing the early postoperative clinical outcomes of minimally invasive THA between anterolateral and posterolateral approaches. In this retrospective study, 62 patients underwent minimally invasive THA via either the anterolateral approach with an intermuscular exposure using the modified Watson-Jones approach (MIS-AL, 34 hips) or mini-incision THA with a posterolateral approach (MIS-PL, 28 hips). We analyzed intraoperative data, postoperative hematological data, postoperative radiographic findings, and the postoperative recovery of muscle strength. The mean surgical time was significantly longer in the MIS-PL than in the MIS-AL group. The mean postoperative serum C-reactive protein level was significantly higher in the MIS-PL group than in the MIS-AL group only on postoperative day 3. There were no significant between-group differences in the postoperative recovery rate of muscle strength during hip abduction. The recovery rate of muscle strength during hip extension was better in the MIS-AL group than in the MIS-PL group only on postoperative day 3. In conclusion, we found no obvious advantage in early postoperative recovery between the MIS-AL and MIS-PL approaches. Therefore, the benefit of rapid postoperative recovery was comparable between the MIS-AL and MIS-PL approaches.

Differences in the setting of acetabular component alignment guides between the supine and lateral positions for total hip arthroplasty.

The acetabular component orientation in total hip arthroplasty is of critical importance to clinical results. Although navigation systems and surgical robots have been introduced, most surgeons still use acetabular component alignment guides. This study aimed to compare the accuracy between modern acetabular component alignment guides for the lateral position and those for the supine position. Thirteen alignment guides for the lateral position and 10 for the supine position were investigated. All the lateral position alignment guides indicated cup alignment in operative definition, and the supine position alignment guides indicated cup alignment in radiographic definition. For lateral position alignment guides, the anteversion actually indicated by the alignment guide itself was smaller than that indicated by the manufacturer by a mean of 6° (maximum, 9°), and the inclination actually indicated by alignment guides themselves was larger than that by the manufacturer (p < 0.01) by a mean of 2° (maximum, 4°). For supine position alignment guides, the inclination and anteversion indicated by the alignment guide itself were identical with those indicated by the manufacturer. The current study showed that the angles actually indicated and those stated by manufacturers were not identical for lateral position alignment guides.

Computerized assessment of Bankart lesions under tension with magnetic resonance arthrography.

Accurate anatomic depiction of Bankart lesions based on magnetic resonance imaging (MRI) is crucial for the treatment of posttraumatic recurrent dislocation of the glenohumeral joint. MR arthrography, the intraarticular injection of dilute gadolinium before MR imaging, improves sensitivity in the detection of shoulder pathology. Abduction and external rotation (ABER) of the shoulder places dynamic stress on the inferior capsular pouch and anterior labroligamentous complex, important structures for anterior shoulder stability. This study sought to determine whether MR arthrography, by use of computerized image analysis, can visualize Bankart lesions better with the shoulder in the neutral position or in ABER. We evaluated 12 shoulders after traumatic anterior dislocation. The MR images were analyzed with image-analyzing software. We compared 3 parameters at 5 levels of the glenoid in the neutral position and in ABER: detachment (the length of detachment between the anterior glenoid rim and the anterior periosteal attachment), displacement (the distance between the anterior glenoid rim and the tip of the displaced labrum), and Bankart area (the area bounded by the detachment line, the displacement line, and the anterior aspect of the Bankart lesion). MR images revealed that Bankart lesions were under tension in ABER and lax and redundant with the shoulder in the neutral position. All 3 parameters were greater in ABER than in the neutral position in all cases (P = .012, P = .0006, and P = .012). Computerized image assessment of MR arthrography with the shoulder in ABER provides excellent visualization and evaluation of Bankart lesions.