Minimal invasive posterior total hip arthroplasty: are 6 weeks of hip precautions really necessary?

INTRODUCTION: Postoperative hip dislocations have been reported in 0.5 to 10.6 % of patients after primary posterolateral total hip arthroplasty (THA). Hip precautions are currently recommended for 6 weeks postoperatively to reduce early dislocation and facilitate healing of the posterior soft tissue repair. MATERIALS AND METHODS: To determine the impact of a modified 4-week precaution protocol on the dislocation rate, 698 consecutive patients (797 hips) operated by a single surgeon between September 2008 and December 2012 were retrospectively evaluated. All patients had a standard THA using a minimal invasive posterior approach with posterior soft tissue repair and 28-36-mm head size. 98.7 % of the patients were available for follow-up. RESULTS: There were eight (1 %) dislocations in 797 hips in the first 12 months after surgery with 4 weeks of hip precautions. The average time to dislocation was 7.5 weeks after surgery (range 1.0-16.9 weeks); two dislocations (25 %) took place in the first 4 weeks. CONCLUSIONS: Shortening the time of posterolateral hip precautions from 6 to 4 weeks after surgery does not increase the risk of postoperative dislocation.

Bilateral anterior dislocation of the shoulder: review of seventy cases and proposal of a new etiological-mechanical classification.

BACKGROUND: Although anterior shoulder dislocation is common in everyday practice in Emergency Departments, bilateral presentation is a rare entity. OBJECTIVES: The aim of this article is to report two additional cases of this rare injury and to introduce a new mechanism that can produce it. We made an exhaustive review of the literature and found 68 cases in printed publications. Also, we analyzed the mechanism of injury and the presence of predisposing factors, and propose a new etiological-mechanical classification. CASE REPORT: One case occurred after a trivial fall, and the other was produced by a mechanism not previously reported: the patient pushed strongly forward, expecting a resistance and finding none, his arms kept the forward movement and the shoulders dislocated. DISCUSSION: This lesion has a bimodal distribution, affecting mainly men (70%) with a mean age of 33.5 years, whereas in women, the average age is 57 years. The most common cause is trauma (50%), followed by muscle contractions (37%) due to seizures of different causes (epileptic, hypoglycemia, toxic, or hypoxic) or electrocution. In 15.7% of the cases, the diagnosis of bilateral anterior dislocation was not acute (<3 weeks), and in virtually all of these cases it was not traumatic. CONCLUSION: The bilateral anterior shoulder dislocation may not be as rare as previously thought and must be taken into account in emergency services. The authors propose a new etiological-mechanical classification. Also, the importance of radiologic diagnosis must be highlighted.