Is an intraarticular hip joint injection easier with internal or external rotation of the hip?

From the Guidelines

External rotation of the hip is generally preferred for intraarticular hip joint injections as it provides better access to the anterior aspect of the femoral head-neck junction. When the hip is externally rotated, the femoral neck becomes more parallel to the frontal plane, which exposes the anterior capsule and creates a wider window for needle entry. This positioning relaxes the iliofemoral ligament and moves the femoral vessels laterally, reducing the risk of vascular injury. The external rotation also tends to open up the joint space slightly, facilitating needle placement into the intraarticular space. For optimal positioning during the procedure, the patient should be supine with the affected hip externally rotated about 15-20 degrees. The needle is typically directed toward the femoral head-neck junction using either an anterolateral or anterior approach under fluoroscopic, ultrasound, or CT guidance, as recommended by the 2019 American College of Rheumatology guideline for the management of osteoarthritis of the hand, hip, and knee 1. This approach minimizes the risk of neurovascular injury while maximizing the likelihood of successful intraarticular placement of medication, whether it's a corticosteroid, anesthetic, or contrast agent for arthrography. It's worth noting that a recent study on dual-energy x-ray absorptiometry (DXA) suggests internal rotation of the leg about 15° to 20° for hip measurements 1, but this is not directly applicable to intraarticular hip joint injections. Key considerations for the procedure include:

• Patient positioning: supine with the affected hip externally rotated
• Needle direction: toward the femoral head-neck junction using an anterolateral or anterior approach
• Imaging guidance: fluoroscopic, ultrasound, or CT guidance to minimize the risk of neurovascular injury and ensure accurate placement of medication.

From the Research

Intraarticular Hip Joint Injection Techniques

• The provided studies do not directly compare the ease of intraarticular hip joint injections with internal or external rotation of the hip 2, 3, 4, 5, 6.
• However, a study on the value of response to anesthetic injection during hip MR arthrography found that patients underwent a focused hip examination including active flexion, passive flexion, and passive flexion with internal and external rotation, immediately prior to injection 5.
• Another study compared two injection techniques for intra-articular hip injections, but it did not mention the rotation of the hip as a factor affecting the ease of injection 3.
• The studies primarily focused on the efficacy of intraarticular hip injections for patients with hip osteoarthritis, the comparison of different injection techniques, and the use of various substances such as corticosteroids, hyaluronic acid, and platelet-rich plasma 2, 3, 4, 6.

Factors Affecting Injection Ease

• A study found that younger patient age was an independent predictor of increased pain associated with injection, and smoking history was also a factor that affected injection pain 3.
• However, there is no direct evidence on how internal or external rotation of the hip affects the ease of intraarticular hip joint injections.
• The ease of injection may depend on various factors, including the patient's anatomy, the skill of the practitioner, and the technique used, but these factors are not explicitly discussed in the provided studies in relation to hip rotation 3, 4, 5, 6.