Injections

Question 1

Indications for injections?

Answer 1

• OA
• RA
• gouty arthritis
• synovitis
• bursitis
• tendonitis
• muscle trigger pts
• carpal tunnel syndrome
• wound anesthesia

Question 2

Components of local infiltration?

Answer 2

• injecting into subq tissue open wounds: provides good anesthesia: little discomfort while injecting
• b/f injecting: clean and sterilize the wound
• epi decreases blood loss
• avoid toxic doses of lidocaine

Question 3

What are field blocks used for?

Answer 3

• good for superficial lesions such as skin abscesses: local anesthesia not effective and painful, may spread infection
• skin prep w/ betadine or alcohol
• inject slowly while advancing needle, only need to go through skin 2x

Question 4

Components of digital blocks?

Answer 4

• use small needle (25-27 gauge)
• start dorsally, go down each side of proximal phalanx: inject as you go and change angle
• don’t use if there is vascular compromise

Question 5

When are trigger pt injections?

Answer 5

• inflamed tendon/bursa by bony prominence:
  combo of lidocaine and steroid, when conservative tx fails and for Dx
• tennis elbow: lateral epicondylitis (pain w/ resisted wrist dorsiflexion)
• greater trochanteric bursitis (pain w/ stretching of lateral side of hip)
• ischial tuberosity bursitis: Weaver’s bottom (pain w/ resisted knee flexion)
• skin prep w/ betadine swab x3 or chloraprep x1 (let dry)
• slow injection into pt of max tenderness: advance needle to bone and then withdraw 2 mm

Question 6

Why inject jts?

Answer 6

• can be jt or soft tissue
• inflammation: degenerative jt disease, bursitis, tendinitis
• corticosteroid injection helps decrease inflammatory rxn (includes limiting capillary dilation + vascular permeability)

Question 7

What are basic principles b/f starting jt injection?

Answer 7

• hx and exam
• try conservative tx: NSAIDs and cont after jt injection
• careful pt selection
• consent
• know your anatomy
• undertake as few injections as possible to settle problem, max 3-4 in a single jt

Question 8

Risks of jt injections?

Answer 8

• infections in healthy pts
• soft tissue infection
• acceleration of septic jt
• subq atrophy and skin depigmentation in less than 1%: where steroid injected subq
• steroid flare: facial flushing, first 24-48 hrs: clears in 1-2 days
• exacerbation of diabetes: warn pts to monitor their BGs
• cartilage damage (rare)
• tendon rupture: only if injecting around tendon
• allergic rxn
• anaphylactic rxn: w/in 5-10 min of injection

Question 9

CIs to jt injection?

Answer 9

• adjacent osteomyelitis
• evidence of bacteremia or febrile illness
• hemarthosis
• impending (scheduled w/in days) jt replacement surgery
• infectious arthritis
• jt prosthesis
• osteochondral fx
• periarticular cellulitis/severe dermatitis/ soft tissue infection
• poorly controlled DM
• uncontrolled bleeding disorder or coag
• clotting disorder and anticoagulation (Correct b/f injecting): prob ok if INR is less than 1.8
• broken skin or cellulitis over injection site
• jt infection
• allergy to local anesthetic or steroid preservative
• immunosuppressed (by drugs or disease)

Question 10

When should you inject jts w/ caution?

Answer 10

• charcot jt (neuropathic sensory loss)
• tumor
• neurogenic disease
• active infections (TB)
• hypothyroidism
• bleeding dyscrasias
• diabetics (likely to raise BG for several days)

Question 11

What informed consent should you go over w/ your pt?

Answer 11

• risks: infection, bleeding, allergic rxn, pain
• benefits: simple office procedure - may provide relief for pts too frail for definitive tx
• realistic expections:
  may not help or only for a few months, may have increased pain for a day or 2 after the injection, may take several days to take effect

Question 12

What are the steroids used for jt injections?

Answer 12

• some take quicker effect, others last longer
• short acting preps (soluble):
  hydrocortisone
  prednisilone
• long acting preps:
  kenalog, aristospan, depo-medrol, decadron, triamcinolone acetonide
• combo preps: (soluble and depot): celestone soluspan
• half life of intra-articular injections:
  depo medrol 6 days
  kenalog 22 days
  aristospan 33 days

Question 13

Approach to the knee injection?

Answer 13

• best approach is path of least obstruction and max access to synovial cavity: which would be superolateral** (or anteromedial - can inject into fat pad rather than jt, or anterolateral, superomedial)
• plain XRs recommended for assessment of bony anatomy of individual knee jt
• knee injection site can be selected according to pt’s bony anatomy and marked w/ the tip of retracted ball pt pen b/f sterile prep
• 5 ml 1% lidocaine and 20-80 methylprednisolone
• this is one of the MC jts for PCP to aspirate and inject

Question 14

Reasons for shoulder injections?

Answer 14

• intra-articular: arthritis, rotator cuff tear, and frozen shoulder
• subacromial:
  rotator cuff tendinitis, bursitis
• AC jt: infammation/arthritis

Question 15

Routes for shoulder injections?

Answer 15

• posterior:
  MC (have pt sitting), 2 cm below base of acromion, 2 cm medial to edge of humerus, can feel jt move in towards tip of coracoid process
• anterior:
  not used as much, have pt supine, fingertip below clavicle and lateral to tip of coracoid process (inject into upper half of jt, avoid brachial plexus)
• can usually feel the jt move
• AC jt: pt sitting w/ hands behind back, palpate the jt, inject from above, angle medially

Question 16

After care for jt injection?

Answer 16

• PROM after injection
• explain that immediate effect is due to local anesthetic, steroid may take several days and they may have a flare up of pain b/f seeking benefit from steroid
• ok to use ice/OTC anti-inflammatories: don’t use hot pad
• call if signs of infection/allergic rxns