Hip Joint Injection

Hip joint injections can be performed with a variety of image guidance, including fluoroscopy and ultrasound, which are used to administer MRI arthrogram injectate, or a steroid containing anaesthetic arthrogram injectate. 
==Anatomy==
An important anatomical concept is that internal rotation of the hip improves visualisation of the femoral neck. External rotation results in the greater trochanter obscuring the neck.
==Indications and Evidence==
*Therapeutic - e.g. hip osteoarthritis. All injection options including saline give moderate relief of pain up to 8 weeks.
*Diagnostic - good relief of pain with local anaesthetic injection predicts good outcomes from total hip arthroplasty. 
*MRI: labral injury
==Contraindications==
*Absolute: anaphylaxis to contrast/ injectates, active local/ systemic infection 
*Relative, bleeding diathesis, recent injection with steroid in same/ other body parts (anaesthetic arthrogram), unable to remain still for the procedure
==Equipment==
* ultrasound machine, sterile probe cover and a skin marker (ultrasound)
* skin marker, a metal rod for marking and short connecting tube (fluoroscopy)
* skin cleaning product
* sterile drape
* sterile field and tray for sharps
* syringe selection i.e. 10mL, 5mL and 20mL
* larger bore drawing up needle
* needle to administer local anaesthetic i.e. 25-gauge needle
* needle to cannulate the joint i.e. 22-gauge needle Quincke needle
* injectants i.e. local anaesthetics, iodinated contrast, corticosteroid preparation
* sterile gauze
* adhesive dressing
==Technique==
Ultrasound guidance is less painful and more convenient than fluoroscopy, with 98% of patients preferring ultrasound.
===Ultrasound Guided===
* Patient Position: optimise patient positioning by laying them supine, with a bolster on the lateral aspect of the ipsilateral foot, holding it in internal rotation
* Identify the joint
** Use a linear probe, or in obese patients a curvilinear probe.
** Identify adjacent neurovascular structures
** Identify the anterior hip joint in a longitudinal plane; parallel to the long axis of the femoral neck, and then optimise imaging and mark the skin entry point at the end of the probe.
* Clean skin and draw up appropriate medications. Consider local anaesthesia along the proposed needle path.
* Needle approach
** Under ultrasound guidance insert the needle in-plane with the probe in a caudal-cranial direction targeting the femoral head-neck junction (anterior joint recess) of the femur and reach the bone
** Administer injectate under direct visualisation
In obese patients where even a spinal needle can't reach the joint, another option is going anterolaterally. Orient the probe axially, and view the femoral head and acetabular rim. This often will shorten the distance to the joint. Approach the joint anterolaterally, avoiding the neurovascular bundle, and advance until the tip rests on the femoral head. 
File:Hip injection anterior longitudinal approach.jpg|Anterior longitudinal approach for an in-plane hip joint injection.
File:Hip joint injection anterior longitudinal approach ultrasound.jpg|Anterior longitudinal approach. The needle is introduced from an inferior and anterior approach, lateral to the femoral neurovascular bundle (arrow). A, acetabulum; H, femoral head; N, femoral neck; double arrow – anterior joint recess.
File:Hip joint injection anterolateral approach ultrasound.jpg|Anterolateral approach. Transverse image of the hip joint. The needle is introduced from a lateral and anterior approach, to rest on the femoral head (arrow). A, acetabulum; H, femoral head; N, femoral neck; LAT, lateral; MED, medial.
===Fluoroscopy Guided===
==== Direct Anterior ====
This is the most common method where the needle is parallel to the x-ray beam. There are various targets - lateral femoral head, lateral femoral neck, central femoral neck, and medial femoral neck. The lateral femoral head-neck junction reduces the change of iliopsoas bursa injection. The medial femoral neck can provide a larger aspirate but is closer to the neurovascular bundle. The femoral head approach is the most painful but the least likely to have extra-capsular contrast injection.
* Patient lies supine with the hip in slight internal (10–15°). The feet can be taped together to facilitate this positioning.
* Palpate the neurovascular bundle
* Obtain an AP view
* There are two possible targets - the centre of the femoral head (direct anterior - eye of needle approach) or lateral to the centre (anterior oblique - inferior to superior, or anterior oblique - lateral to medial) under AP imaging
* clean skin and draw up appropriate medications
* consider local anaesthesia along the proposed needle path
* check an intra-articular needle tip position with a small amount of iodinated contrast via connection tubing and save a post-injection image
* remove the needle and apply dressing as required
==== Anterolateral approach (inferior to superior) ====
This uses a inferior skin entry, typically if the patient has a deep groin crease or if the femoral vessels lie very laterally. 
* The needle puncture site is at the femoral neck just medial to the intertrochanteric line. 
* The needle is angled 60° superomedial to target the superior lateral femoral head-neck junction.
==== Anterolateral approach (lateral to medial) ====
This is useful is obese patients with deep groin folds, those with a large abdominal pannus, those who can't lie supine, and those with a hip contracture. 
* The patient lies semi-decubitus to the contralateral side with a foam wedge supporting the body. This allows the panus to move away from the hip
* The entry site is the superior edge of the greater trochanter (identified using fluoroscopy)
* Note, on lateral imaging the target hip looks smaller than the contralateral hip due to image magnification
* The needle path is lateral to medial, with an angle of 45 degrees
* The target is the superior femoral head neck junction
* When the target is approach swing the C arm to an AP view to direct towards the junction
Challenging situations in our practice involve patients who are obese with a deep groin fold and overlying panniculus, who cannot lie flat, or who have a hip contracture. In these cases, we have found success in using the angled anterior-oblique approach with a lateral to medial needle path (Fig. 7) [72]. The patient is rolled semi-decubitus to the contralateral side with a foam wedge supporting the body. In this position, gravity displaces the panniculus away from the hip of interest. The superior edge of the greater trochanter is located with fluoroscopy and marked as the skin entry site. After skin puncture, the needle is angled 45° from lateral to medial, targeting the superior femoral head-neck junction [72].
==== Novel anterolateral approach ====
A novel approach was described by using a direct down the beam approach from lateral to medial. This is to avoid passing through the neurovascular bundle. 
* Obtain a scout AP fluoroscopic image of the desired femoral neck with the patient in a supine position
* Move the C arm to be approximately 20 degrees ipsilateral oblique and 15 degrees caudal to bring the anterolateral femoral neck into view
* Introduce the needle lateral to the femoral neck and advance superiorly and medially aiming for the midfemoral neck
* Aim for the needle tip to be either at 6 o clock to the base of the femoral head on the neck or at 3 o clock.
===Landmark Guided===
A landmark guided technique has been described with 93% accuracy. The paper should be read in full and the patient's radiographs thoroughly assessed for anatomical variations before attempting.
==Complications==
Initial injections can be extra-articular but if the needle is repositioned before giving the injectate this often has no effect. Excess extra-articular solution may distort an MRI arthrogram, especially if the MRI injectate is outside of the joint. The most serious complication is an infection causing septic arthritis. A steroid flare after injection can occur but symptoms will resolve after 1 - 2 days. Injections should be postponed if there are signs and/or symptoms of local and/ or systemic infection. Fat necrosis causing skin dimpling and skin discolouration can occur due to steroid leaking into the surrounding soft tissues 3, although less common in deeper injections.
==Aftercare==
Ensure patient is able to mobilise independently.
==Videos==
<youtube>https://www.youtube.com/watch?v=7eu23GQYxt0</youtube>
==External Links==
==Resources==
==References==
Category:Infoboxes
Category:Partially complete articles
Category:Pelvis, Hip and Thigh Procedures