total knee arthroplasty

Preop antibiotic (give 60 min before incision)

Cefazolin 2 g IV (3 g if >120 kg) within 60 minutes of incision; vancomycin or clindamycin if beta-lactam allergy (start within 120 minutes). Redose cefazolin q4h or for EBL >1500 mL.

Local anesthetic

• —Periarticular injection cocktail commonly used — ropivacaine or bupivacaine +/- epinephrine, ketorolac, morphine (surgeon recipe varies)
• —Liposomal bupivacaine (Exparel) per surgeon preference

Irrigation

• —Normal saline pulse lavage
• —Some surgeons use dilute betadine or chlorhexidine lavage prior to implantation

Other field meds

• —Tranexamic acid (topical) — verify dose and concentration
• —Bone cement (PMMA) — monitor for cementing reaction/hypotension

Labeling

All medications on the sterile field must be labeled — name, strength, expiration. Periarticular cocktail components labeled individually before mixing.

Core trays

• —Total Knee Major/Minor set
• —Implant-specific instrument trays (Stryker Triathlon, Zimmer Persona/NexGen, DePuy Attune, Smith & Nephew Journey — per surgeon)
• —Bone hooks, Hohmann retractors, Z-retractors
• —Oscillating saw and saw blades
• —Pulse lavage

Specialty items

• —Trial components (femoral, tibial, poly insert, patellar button)
• —Final implants — confirm size before opening
• —Bone cement (PMMA) — usually 2 packs, with mixer/vacuum system
• —Cement restrictor (intramedullary plug)
• —Patellar reamer/clamp if resurfacing patella
• —Alignment guides (intramedullary or extramedullary), or robotic/navigation arrays if used

Energy devices

• —Monopolar Bovie with extended tip
• —Bipolar available

Scopes / robot

• —Mako, ROSA, or VELYS robotic platform if surgeon uses navigation/robotics
• —Computer navigation system (optional)

Primary position

Supine with operative leg able to flex; non-operative leg may be flat or in a well-leg holder. Bump under ipsilateral hip optional. Tourniquet high on operative thigh. Leg positioner or lateral post used.

Variations

• —Some surgeons use a leg holder (e.g., De Mayo, Stulberg) to hold the knee in flexion
• —Lateral post + foot bump to hold knee at 90 degrees
• —Tourniquet may not be used if surgeon prefers tourniquet-less technique

Pressure points

• —Heels
• —Sacrum
• —Contralateral peroneal nerve (well-leg)
• —Tourniquet site (avoid wrinkles, pad skin)
• —Bilateral elbows on arm boards

Pearls

• —Confirm correct surgical site/side with surgeon before prep — site marking must be visible after prep and drape
• —Place SCDs on non-operative leg before positioning
• —Pad under contralateral knee to offload peroneal nerve
• —Document tourniquet site, pressure, inflation/deflation times
• —Safety strap above non-operative knee

Prep solution

• —ChloraPrep (2% CHG / 70% IPA) — most common
• —Alternative: Betadine paint/scrub if CHG contraindicated
• —Allow full dry time before draping (alcohol-based prep is flammable)

Prep area

Operative leg circumferentially from tourniquet to and including the foot. Foot is often covered with a stockinette/coban after prep.

Draping

Leg held up by assistant or holder; impervious U-drape under thigh, extremity drape over the leg through a fenestration, stockinette and Coban on foot, then split sheet to seal. Iodine-impregnated incise drape (Ioban) commonly applied over the knee.

Pearls

• —Two preps are common — many surgeons prep twice given joint implant
• —Confirm prep is fully dry before Ioban and drapes
• —Have a large bag/pouch drape to collect irrigation
• —Keep stockinette and Coban available — color-coded per facility

Typical sutures

• —Capsule/arthrotomy: #1 or #2 Vicryl or barbed suture (Quill/Stratafix)
• —Subcutaneous: 2-0 Vicryl
• —Subcuticular: 3-0 Monocryl
• —Alternative skin: staples

Staplers

• —Skin stapler (surgeon preference vs subcuticular closure)

Energy

• —Monopolar electrosurgery (Bovie) — coag setting per surgeon
• —Bipolar for posterior structures

Hemostatic agents

• —Tranexamic acid (TXA) — IV and/or topical/intra-articular, surgeon dependent
• —Topical thrombin or Floseal occasionally

Wound dressings

• —Xeroform or Adaptic over incision
• —4x4 gauze
• —ABD pad
• —Kerlix or Webril roll
• —Ace wrap or Coban from foot to thigh
• —Alternative: Aquacel Ag + Mepilex border dressing (silver impregnated) per surgeon

Drains

• —None typical — most surgeons no longer use drains routinely
• —Hemovac or ConstaVac autologous transfusion drain occasionally per surgeon

Application notes

Apply dressing before tourniquet deflation in some practices, others deflate first to assess hemostasis. Confirm with surgeon. Cryotherapy device (Game Ready, Polar Care) often applied in PACU.

Typical specimens

• —Resected bone (femoral condyles, tibial plateau, patella if resurfaced) — usually discarded per facility policy, NOT routinely sent to pathology unless surgeon requests
• —Synovium if unusual appearance

Handling

Confirm with surgeon whether resected bone goes to pathology, is discarded, or is saved for the patient. If infection suspected, send tissue and synovial fluid for culture (aerobic, anaerobic, fungal, AFB).

Labeling notes

If sent: label with patient identifiers, site (e.g., 'right knee, distal femur'), and surgeon. Verbal verification with surgeon at time of specimen handoff.

Common pitfalls

• —Verify with facility preference card — implant system, robotics, cement vs cementless, patella resurfacing all vary by surgeon
• —Wrong-sided surgery risk — site mark must be visible after drape
• —Tourniquet time tracking — notify surgeon at intervals
• —Cement timing — open and mix only when surgeon calls for it; PMMA has working/setting window
• —Implant must match trial — read sizes back to surgeon before opening final implants
• —Do not deflate tourniquet without surgeon's direction

Conversion risks

• —Intraoperative fracture (femoral condyle, tibial plateau, medial malleolus from saw)
• —Need for stemmed/revision components if bone loss greater than expected
• —Conversion to constrained or hinged implant for instability

Vascular structures at risk

• —Popliteal artery and vein (posterior to knee — at risk during posterior capsule release and tibial cut)
• —Common peroneal nerve (lateral, at risk with valgus correction)
• —Saphenous nerve branches (medial incision)

Reportable events

• —Wrong-site surgery
• —Retained foreign object
• —Intraoperative fracture
• —Vascular injury requiring vascular consult
• —Cement implantation syndrome / cardiovascular collapse at cementing
• —Medication error (TXA, antibiotic, local cocktail)
• —Tourniquet-related injury or excessive tourniquet time

Initial count

Initial count of sponges, sharps, and instruments performed by scrub and circulator before incision; documented per AORN.

Closing count

Closing counts performed before closure of capsule and again before skin closure. Verify all needles, blades, bovie tips, and instruments. Confirm count correct prior to dressing.

Special items to count

• —Saw blades — account for each
• —Bovie scratch pad/tip
• —Suture needles (often barbed — count carefully)
• —Cement spacers/restrictor packaging
• —Bone wax if used

Step-by-step

• —Patient to room, time-out with site/side verification and implant availability confirmed. Antibiotics given within 60 min of incision.
• —Anesthesia induction (spinal or general); regional block (adductor canal) often placed pre-op or in block area.
• —Position supine, place SCDs on non-op leg, pad pressure points, apply tourniquet high on op thigh, attach leg holder/post.
• —Clip hair if needed, prep operative leg circumferentially (often x2), allow dry, drape with extremity drape, stockinette/Coban foot, Ioban over knee.
• —Surgeon exsanguinates leg with Esmarch, inflates tourniquet — circulator documents time and pressure.
• —Midline skin incision, medial parapatellar arthrotomy (most common), patella everted or subluxed.
• —Bone cuts: distal femur, then tibia (or surgeon's preferred sequence), using alignment guides or robotics. Trial components placed, ROM and stability assessed.
• —Pulse lavage irrigation, dry the bone surfaces, mix cement (call out 'cement now'), implant final components in sequence, pressurize cement, remove excess.
• —Hold pressure while cement cures, place poly insert, +/- patellar resurfacing, deflate tourniquet (timing per surgeon), achieve hemostasis.
• —Periarticular injection given, closing count, layered closure (capsule, subQ, skin), apply dressing and Ace/Coban wrap.
• —Emergence, transfer to stretcher carefully protecting operative leg, report to PACU including tourniquet time, EBL, implants used, antibiotics.

Circulator notes

• —Verify implants (femoral, tibial, poly, patella) in room AND backup sizes available before incision
• —Document tourniquet pressure, inflation and deflation times — notify surgeon at 60, 90, 120 minutes
• —Have cement mixer/vacuum ready; ensure room ventilation and scavenging during mixing (PMMA fumes)
• —Confirm TXA dose with surgeon/anesthesia
• —Capture implant stickers/lot numbers for the chart and implant log
• —Anticipate cement reaction — monitor BP at cementing
• —Have warm saline for pulse lavage
• —Check patient temperature — use forced-air warmer on upper body