Anesthesiologist's Manual of Surgical Procedures, 4th ed.

Orthopedic Surgery

Chapter 10.5

Knee Surgery

James I. Huddleston MD

Surgeon

John J. Csongradi MD

Surgeon

Stuart B. Goodman MD, PhD, FRCSC, FACS

Surgeon

Frederick G. Mihm MD

Anesthesiologist

Christoph Egger Halbeis MD, MBA

Anesthesiologist

P.1014

Arthroplasty of the Knee

Surgical Considerations

Description: In this procedure, an arthrotomy of the knee joint is performed, and metallic and plastic components are used for replacement of the knee joint surfaces (total knee replacement). The femur, patella, and tibia are exposed; cartilage and minimal bone are excised with a saw. The new components may be cemented or uncemented. Alternatively, arthroplasty may be performed on only one compartment of the knee (i.e., medial/lateral unicompartmental knee replacement). In revision procedures, one or more components of the old joint are removed and new components are placed. In resection or excision arthroplasty of the knee, (usually for infection of the prosthesis), the components are removed, but not replaced.

Usual preop diagnosis: Arthritis of knee; arthrosis of knee; loose (or malpositioned) knee prosthesis; infected knee

Summary of Procedures

	Knee Replacement	Revision	Resection/Excision
Position	Supine	⇐	⇐
Incision	Anterior or anteromedial over patella	⇐	⇐
Special instrumentation	Appropriate prostheses and instrumentation	Special instruments for excising cement	⇐
Unique considerations	± Tourniquet; ± SCD	⇐	⇐
Antibiotics	Cefazolin 1 g iv q 6–8 h × 24 h (vancomycin or clindamycin for 24 h if penicillin allergic)	⇐	⇐
Surgical time	2 h	3–4 h or more	3 h
Closing considerations	In infected or complex revision cases (rare), a local or free flap is required.	⇐	⇐
EBL	300–500 mL	500–1,000 mL	⇐
Postop care	Bulky dressing or splint; continuous passive motion (CPM) may begin in the PACU or ward	⇐	Splint/cast
Mortality	Rare	⇐	⇐
Morbidity	DVT, without prophylaxis: 50–75%	⇐	⇐
	DVT, with prophylaxis (e.g., low-molecular-weight heparin, coumadin, SCD, antiembolism stockings): 2–3%	⇐	⇐
	Postop subluxation/dislocation of patella: 20%	> 30%	–
	Superficial wound necrosis: 10–15%	> 10–15%	≥ 10–15%
	Wound infection: Primary rheumatoid or psoriatic arthritis, diabetes: 5–10%	> 5–10%	Rare
	Primary osteoarthritis (OA): 1%
	PE: 1–7%	⇐	⇐
	Postop subluxation/dislocation of knee joint: 1–6%	≥ 1–6%	–
	Late aseptic loosening requiring revision after ~10 yr: 5%	–	–
	Peroneal nerve injury: 1–5%	> 1–5% (more common in difficult revisions)	1–5%
	Urinary retention requiring catheterization: Common	–	–
	Hematoma requiring reoperation: Rare	–	–
	Hypotension	–	–
	Knee stiffness	–	–
	Intraoperative fracture: Rare	⇐	⇐
	Wound dehiscence: Rare	–	–
	Fat embolism: Rare	–	–
	Vascular injury to popliteal vessels: Rare	–	–
Pain score	7	8	9

P.1015

Patient Population Characteristics

Age range	Generally, > 60 yr. Arthritis of the knee (e.g., rheumatoid arthritis or juvenile rheumatoid arthritis); hemophilia, ≥ 18 yr
Male:Female	1:1
Incidence	Common (~400,000/yr in the United States)
Etiology	Arthrosis of the knee (degenerative joint disease [DJD] or OA); seropositive or seronegative arthritis; traumatic arthritis; hemophiliac arthropathy of the knee
Associated conditions	Dependent on primary condition (e.g. osteoarthritis)

Anesthetic Considerations

See Anesthetic Considerations for Knee Procedures (p. 1026).

Suggested Readings

1. Blaster RB, Matthews LS: Complications of prosthetic knee arthroplasty. In: Complications in Orthopaedic Surgery,3rd edition. Epps CH Jr, ed. JB Lippincott, Philadelphia: 1994, 1057–86.
2. Burke DW, O'Flynn H: Primary total knee arthroplasty. In Chapman's Orthopaedic Surgery,3rd edition. Chapman MW, ed. Lippincott Williams & Wilkins, Philadelphia: 2001, 2869–96.
3. Guyton JL: Arthroplasty of the ankle and knee. In: Campbell's Operative Orthopaedics,9th edition. Crenshaw AH, ed. Mosby-Year Book, St. Louis: 1998, Vol 1, 232–94.
4. Insall JN: Total knee replacement. In: Surgery of the Knee.Insall JN, ed. Churchill Livingstone, New York: 1984, 587–695.
5. Kuper M, Rosenstein A: Infection control in total knee and total hip arthroplasties. Am J Orthop2008; 37(1):E2–5.
6. NIH Consensus Statement on total knee replacement. NIH Consens State Sci Statements. 2003; 20(1):1–34.
7. Vince KG: Revision knee arthroplasty and arthrodesis of the knee. In Chapman's Orthopaedic Surgery,3rd edition. Chapman MW, ed. Lippincott Williams & Wilkins, Philadelphia: 2001, 2897–2952.

Arthrodesis of the knee

Surgical Considerations

Description: In this procedure, the femur is fused to the tibia, obliterating the knee joint. Through a midline incision and anterior or median parapatellar arthrotomy, the cartilage surface and a small amount of bone are excised. The cut ends are opposed and aligned in 0–20° of flexion and 5–10% of valgus. The bones are stabilized with plates, screws, an intramedullary rod, or an external fixator.

Usual preop diagnosis: Arthritis or other arthrosis of the knee; previous septic arthritis of the knee; failed or infected knee arthroplasty

P.1016

Summary of Procedures

Position	Usually supine
Incision	Anterior midline over knee
Special instrumentation	External fixator; internal fixation with plates and screws or intramedullary nail
Unique considerations	Intraop radiographs or I.I.; tourniquet
Antibiotics	Cefazolin 1 g iv q 6–8 h × 24 h (vancomycin or clindamycin for 24 h if penicillin allergic)
Surgical time	3 h (+ 1 h, if necessary, to excise total knee arthroplasty)
Closing considerations	Cast or splint while anesthetized
EBL	< 100 mL, if tourniquet and local fixation used. 500–1000 mL, if no tourniquet used, or if intramedullary procedures are used.
Mortality	Rare, but depends primarily on age and medical condition of patient.
Morbidity	Thromboembolism ≥ incidence following total knee replacement: DVT (without prophylaxis): 50–75% DVT (if prophylaxis used): 10–20% PE (if no prophylaxis; reduced if anticoagulation or SCDs used): 1–7% Failure of fusion (nonunion), malunion: 10% After failed knee replacement: 19–44% With Charcot joint: as high as 50% Pin tract infection: ≥ 1–10% Wound infection: 5% Deep infection and osteomyelitis Urinary retention requiring catheterization, UTI: Common Breakage or failure of internal or external fixation: Rare Fat embolism: Rare GI bleed, MI: Rare Hematoma: Rare Hypotension: Rare Intraop femoral or tibial fracture: Rare Neurological injury, usually popliteal nerve or peroneal nerve: Rare Superficial wound necrosis and wound dehiscence: Rare Vascular injury to popliteal vessels: Rare Amputation: Extremely rare (usually 2° acute arterial occlusion or uncontrollable local sepsis)
Pain score	9

Patient Population Characteristics

Age range	Any age
Male:Female	1:1
Incidence	Rare
Etiology	Failed or infected total knee replacement (probably most common etiology); trauma to knee—unreconstructable, intraarticular fractures; total unstable knee or failed ligament repairs with severe DJD in a young patient

Anesthetic Considerations

See Anesthetic Considerations for Knee Procedures (p. 1026).

P.1017

Suggested Readings

1. Blaster RB, Matthews LS: Complications of prosthetic knee arthroplasty. In: Complications in OrthopaedicSurgery, 3rd edition. Epps CH Jr, ed. JB Lippincott, Philadelphia: 1994, 1057–86.
2. Carnesale PG, Stewart MJ: Complications of arthrodesis surgery. In: Complications in Orthopaedic Surgery,3rd edition. Epps CH Jr, ed. JB Lippincott, Philadelphia: 1994, 1279–1308.
3. Christian CA, Donley BG: Arthrodesis of the ankle, knee, hip. In: Campbell's Operative Orthopaedics,9th edition. Canale ST, ed. Mosby-Year Book, St. Louis: 1998, Vol 1, 145–88.
4. Mize R, Johnson EE, Hohl M: Complications of fractures and dislocations of the knee. In: Complications in Orthopaedic Surgery,3rd edition. Epps CH Jr, ed. JB Lippincott, Philadelphia: 1994, 525–56.
5. Vince KG: Revision knee arthroplasty and arthrodesis of the knee. In: Chapman's Orthopaedic Surgery,3rd edition. Chapman MW, ed. Lippincott Williams & Wilkins, Philadelphia: 2001, 2897–2952.

Open Reduction and Internal Fixation (ORIF) of Patellar Fractures

Surgical Considerations

Description: In ORIF of patellar fractures, a short incision over the patella is used to perform a reduction by direct visualization of the fracture fragments of the patella. Since this is generally an intraarticular fracture, the fragments should be reduced precisely. The torn quadriceps retinaculum is also repaired. Part or all of the patella may be excised; pins, wires, and/or screws are normally used to fix the patellar fragments together internally. Thereafter, the knee is casted, or early motion of the knee is started.

Usual preop diagnosis: Fracture of patella; severe degenerative arthritis of patellofemoral joint

Summary of Procedures

Position	Supine
Incision	Anterior over patella
Special instrumentation	Wire, pins, screws as necessary
Unique considerations	Intraop radiographs may be obtained; tourniquet
Antibiotics	Cefazolin 1 g iv q 6–8 h × 24 h (vancomycin or clindamycin for 24 h if penicillin allergic)
Surgical time	1.5–2 h
Closing considerations	Splint or cast usually applied.
EBL	< 100 mL
Mortality	< 1%
Morbidity	Late degenerative arthritis of patellofemoral joint: ~50–60% DVT: ~5% Wound infection, septic arthritis, osteomyelitis: ~5% Delayed union, nonunion, malunion: ~2–5% Knee stiffness: Common Weakness: Common Avascular necrosis: Rare Complex regional pain syndrome: Rare Following patellectomy—quadriceps strength: ~75% of normal
Pain score	7

P.1018

Patient Population Characteristics

Age range	Any age; frequently seen in young, active, healthy adults.
Male:Female	1:1
Incidence	~1% of all skeletal injuries
Etiology	Trauma: falls (60%); motorcycle and motor vehicle accidents (25–35%); industrial injury (6%); degenerative arthritis of patellofemoral joint (rare)

Anesthetic Considerations

See Anesthetic Considerations for Knee Procedures (p. 1026).

Suggested Readings

1. Callaghan JJ, O'rourke MR, Saleh KJ. Why knees fail: lessons learned. J Arthroplasty2004; 19(4 Suppl 1):31–4.
2. Mize R, Johnson EE, Hoh1 M: Complications of fractures and dislocations of the knee. In: Complications in Orthopaedic Surgery,3rd edition. Epps CH Jr, ed. JB Lippincott, Philadelphia: 1994, 525–56.
3. Whittle AP: Fractures of lower extremity. In: Campbell's Operative Orthopaedics,Vol 3, 9th edition. Canale ST, ed. Mosby-Year Book, St. Louis: 1998, 2042–2180.
4. Whittle AP: Malunited fractures. In: Campbell's Operative Orthopaedics,Vol 3, 9th edition. Canale ST, ed. Mosby-Year Book, St. Louis: 1998, 2537–78.
5. Wiss DA, Watson JT, Johnson EE: Fractures of the knee. In: Rockwood and Green's Fractures in Adults,5th edition. Rockwood CA Jr, Green DP, Bucholz RW, Heckman JD, eds. Lippincott-Raven, Philadelphia: 1996, 1919–71.

Repair or Reconstruction of Knee Ligaments

Surgical Considerations

Description: Collateral ligaments usually are repaired by direct suture or by stapling the torn ligaments to bone. Cruciate tears are generally repaired only if bone is avulsed at one end of the ligament, again with direct suture, staples, or screws. For collateral ligament repair, a longitudinal incision is made directly over the ligament medially or laterally. The ligament is exposed by deep dissection and elevation of skin flaps. The torn ligament is repaired by direct suture or by fixing it to bone with a screw or staple. Following closure, the knee is immobilized with a long leg splint or cast. Cruciate ligaments are repaired in similar fashion, except for the approaches: medial parapatellar (with anterior arthrotomy) for the anterior cruciate ligament (ACL) and posteromedial (with posterior arthrotomy) for the posterior cruciate ligament (PCL). Cruciate ligament reconstruction is performed for instability 2° intrasubstance tears of these ligaments. Homografts, such as a portion of the patellar tendon or semitendinosus tendon, normally are used, but allografts or synthetics also are available. (The ligaments of the knee are illustrated in Figs 10.5-1 and 10.5-2.)

Usual preop diagnosis: Trauma

Summary of Procedures

	Repair or Collateral Reconstruction	Repair or Cruciate Reconstruction
Position	Supine	⇐
Incision	Over collateral ligament	Anterior and lateral ACL or medial PCL
Special instrumentation	Staples	Drill guides, staples, screws
Unique considerations	Often arthroscopically assisted; tourniquet	⇐
Antibiotics	Cefazolin 1 g iv (vancomycin or clindamycin if penicillin allergic)	⇐
Surgical time	2 h	⇐
Closing considerations	Splint or cast while anesthetized	⇐
EBL	100 mL	⇐
Postop care	PACU → room or home	⇐
Mortality	Minimal	⇐
Morbidity	Infection: < 1%	⇐
	Thrombophlebitis: < 5%	⇐
Pain score	4	7

P.1019

Patient Population Characteristics

Age range		Young adult
Male:Female		2:1
Incidence		Common
Etiology		Trauma: 100%
Figure 10.5-1. The cruciate ligaments (posterior view). (Reused with permission from Clemente CD. Clemente's Dissector, 2nd edition. Baltimore: Lippincott Williams & Wilkins, 2007: 270.)

P.1020

Figure 10.5-2. The knee joint opened anteriorly. (Reused with permission from Clemente CD. Clemente's Dissector, 2nd edition. Baltimore: Lippincott Williams & Wilkins, 2007: 269.)

Anesthetic Considerations

See Anesthetic Considerations for Knee Procedures (p. 1026).

Suggested Readings

1. Canale ST, ed: Campbell's Operative Orthopaedics,10th edition. Mosby, St. Louis: 2003.
2. Marder RA, Ertl JP: Dislocations and multiple ligamatous injuries of the knee. In Chapman's Orthopaedic Surgery,3rd edition. Chapman MW, ed. Lippincott Williams & Wilkins, Philadelphia: 2001, 2417–34.
3. McCulloch PC, Lattermann C, Boland AL, et al: An illustrated history of anterior cruciate ligament surgery. J Knee Surg2007; 20(2):95–104.

Patellar Realignment

Surgical Considerations

Description: The goal of this procedure is prevention of chronic subluxation or dislocation of the patella. Soft tissue components of the surgery include incision (release) of the lateral patellar retinaculum and reefing or tightening of the medial retinaculum (Fig. 10.5-3). In cases of severe malalignment of the extensor mechanism, the insertion of the patellar tendon may be moved to a new, more medial location (tibial tubercle transfer). In this procedure, the tibial tubercle generally is detached with a saw or osteotomes, leaving a bone pedicle attached distally. The tubercle is then rotated medially on the pedicle and fixed in its new position with a screw. Many surgeons routinely perform an anterior compartment fasciotomy to prevent postop compartment syndrome.

P.1021

Figure 10.5-3. Outer layer of anteromedial aspect of the knee joint. Shows anatomy of the patellar retinaculum. (Reproduced with permission from Hoppenfeld S, deBoer P:Surgical Exposures in Orthopaedics: The Anatomic Approach. Lippincott Williams & Wilkins: 1994.)

Usual preop diagnosis: Chronic patellar subluxation or dislocation

Summary of Procedures

	Patellar Realignment	Tibial Tubercle Transfer
Position	Supine	⇐
Incision	Anteromedial or anterolateral to knee	⇐
Special instrumentation	None	Screws or staples
Unique considerations	Tourniquet	⇐
Antibiotics	Cefazolin 1 g iv (vancomycin or clindamycin if penicillin allergic)	⇐
Surgical time	1 h	1.5 h
Closing considerations	None	Splint or cast while anesthetized
EBL	50 mL	100 mL
Postop care	PACU → room or home	⇐
Mortality	Minimal	⇐
Morbidity	Hemarthrosis: 100%	5%
	Redislocation: 20%	25%
	Thrombophlebitis: 10–20%	⇐
	Compartment syndrome: < 1%	⇐
	Infection: < 1%	⇐
Pain score	6	7

Patient Population Characteristics

Age range	Usually young adult
Male:Female	1:2
Etiology	Trauma (70%); congenital (30%)
Associated conditions	Patellofemoral dysphasia (60–70%)

P.1022

Anesthetic Considerations

See Anesthetic Considerations for Knee Procedures (p. 1026).

Suggested Readings

1. Epps CH Jr, ed: Complications in Orthopaedic Surgery,3rd edition. JB Lippincott, Philadelphia: 1994.
2. Griffin LY, Duralde XA: Adolescent sports injuries. In: Chapman's Orthopaedic Surgery,3rd edition. Chapman MW, ed. Lippincott Williams & Wilkins, Philadelphia: 2001, 2493–2536.

Arthroscopy of the Knee

Surgical Considerations

Description: Knee arthroscopy is used to diagnose and treat intraarticular problems, most commonly torn meniscus, but the procedure is also used for ligament injuries (Fig 10.5-1,10.5-2), osteochondral fractures, loose bodies, arthritis, and infections. In knee arthroscopy, multiple portals or entry points for the arthroscope and instruments generally are used. The most common portals are anteromedial and anterolateral adjacent to the patellar ligament. Other portals may be suprapatellar, parapatellar, and posterior. Portals are made by making a stab wound with a knife and then entering the joint with a combination of sharp and blunt trochars. A diagnostic inspection from one of the anterior portals is normally performed at the outset. A second portal is used with a nerve hook to manipulate intraarticular tissues. If resection or repair is performed, the appropriate instruments are inserted through one of the portals. Meniscus repair and cruciate reconstruction may require separate longitudinal incisions, which are usually posteromedial or posterolateral, for placement of sutures and/or drill holes.

P.1023

Meniscectomy and/or debridement often are performed in conjunction with arthroscopy. Cruciate ligament reconstruction usually is performed with arthroscopic assistance. At the end of the procedure, the knee joint is copiously irrigated with NS or LR solution through one of the portals. Portals are closed with a single suture and Steri-Strips®; compression bandages are applied; and often a knee immobilizer is used.

Usual preop diagnosis: Torn meniscus; cruciate ligament tear; arthritis

Summary of Procedures

	Arthroscopy	Meniscectomy/Debridement	Cruciate Reconstruction
Position	Supine	⇐	⇐
Incision	3–4.5 cm portals	⇐	⇐ + anterior midline and lateral
Special instrumentation	Arthroscopic video system; small biters and graspers	⇐ + shaver	⇐ + drill guides and drills; fixation screws
Unique considerations	Thigh holder; foot of table 90°; ± tourniquet	⇐	⇐
Antibiotics	Cefazolin 1 g iv (vancomycin or clindamycin if penicillin allergic)	⇐	⇐
Surgical time	0.5 h	1–2 h	2–3 h
Closing considerations	No splint; local anesthetic injected	⇐	⇐
EBL	Minimal	⇐	50 mL
Postop care	PACU → home	⇐	⇐ or overnight
Mortality	< 0.1%	⇐	⇐
Morbidity	Hemarthrosis: 5–20%	5%	⇐
	Thrombophlebitis: < 2%	⇐	⇐
	Infection: 0.1%	⇐	⇐
	Stiffness: < 0.1%	< 4%	⇐
Pain score	3	4	6

Patient Population Characteristics

Age range	10–70 yr (usually 20–40 yr)
Male:Female	2:1
Incidence	The most common arthroscopic procedure (85% of total)
Etiology	Trauma (~85%); arthritis (~10%); infection (~5%)
Associated conditions	Usually healthy; systemic arthritis (< 5%)

Anesthetic Considerations

See Anesthetic Considerations for Knee Procedures (p. 1026).

Suggested Readings

1. Coward DB: Principles of arthroscopy of the knee. In Chapman's Orthopaedic Surgery, 3rd edition. Chapman MW, ed. Lippincott Williams & Wilkins, Philadelphia: 2001, 2269–98.

P.1024

2. McGinty JB, ed: Operative Arthroscopy. 3rd edition. Lippincott Williams & Wilkins, Philadelphia: 2002.
3. Silvis ML, Clinch CR, Tillett JS, et al: Clinical inquiries. What is the best way to evaluate an acute traumatic knee injury? J Fam Pract2008; 57(2):116–8.

Knee Arthrotomy

Surgical Considerations

Description: Arthrotomy of the knee is the opening of the joint for drainage, excision of intraarticular tissue (synovium, meniscus, loose bodies), ligament repair/reconstruction, or fracture fixation. The knee generally is opened with a parapatellar incision, either medial or lateral, and the joint capsule is incised just adjacent to the patella. After the intra-articular pathology is addressed, a tight capsular closure is performed, followed by subcutaneous tissue and skin closure.

Variant procedure or approaches: Arthrotomy with debridement may be used for infection or arthropathy which produces debris. In both cases, synovectomy may be necessary.

Usual preop diagnosis: Infection; trauma (fracture, sprain, torn meniscus); arthritis

Summary of Procedures

	Arthrotomy	Arthrotomy with Debridement	Arthrotomy with Synovectomy
Position	Supine	⇐	⇐
Incision	Medial or lateral parapatellar	⇐	⇐
Special instrumentation	Tourniquet	⇐	⇐
Antibiotics	Cefazolin 1 g iv (vancomycin or clindamycin if penicillin allergic)	⇐	⇐
Surgical time	1 h	2 h	2 h
Closing considerations	Compressive dressing; may be splinted; suction drain	⇐	⇐
EBL	100 mL	⇐	⇐
Postop care	PACU → room	⇐	⇐
Mortality	Minimal	⇐	⇐
Morbidity	Hemarthrosis: 100%	⇐	⇐
	Degenerative arthritis: 5–20%	⇐	⇐
	Stiffness: 5%	⇐	⇐
	Thrombophlebitis: 5%	⇐	⇐
	Infection: 1 %	10%	20%
Pain score	7	7	8

Patient Population Characteristics

Age range	Infant–elderly (usually young adult)
Male:Female	1:1
Incidence	Common
Etiology	Infection; trauma; arthritis
Associated conditions	Inflammatory arthritis (20%)

P.1025

Anesthetic Considerations

See Anesthetic Considerations for Knee Procedures (p. 1026).

Suggested Reading

1. Epps CH Jr, ed: Complications in Orthopaedic Surgery, 3rd edition. JB Lippincott, Philadelphia: 1994.

Repair of Tendons—knee and leg

Surgical Considerations

Description: Acute ruptures of tendons in the lower limb are repaired by direct suture and sometimes reinforced with part of another tendon. At the knee, patellar tendon ruptures are most common; at the ankle, Achilles tendon ruptures are most common. A longitudinal incision generally is made directly over the tendon. The tendon sheath is opened and tendon ends reapproximated with a nonabsorbable tendon stitch. If necessary, the repair may be augmented by synthetic tape or fascia, or protected with a wire that takes tension off the repair. The tendon sheath is closed separately from the skin incision; and a cast or splint is applied. Achilles tendon repair and posterior tibial tendon repair require different positioning. For an Achilles tendon repair, the patient is placed prone, and a longitudinal incision is made just medial to the tendon, spanning the rupture. The tendon sheath is incised and carefully protected. Torn ends of the tendon are approximated with multiple tendon stitches and may be protected with a fascial flap developed from the gastrocnemius fascia. The tendon sheath is closed carefully, followed by skin wound closure. A splint or cast is applied with the foot in equinus (plantar flexion).

Usual preop diagnosis: Tendon rupture

Summary of Procedures

	Posterior Tendon Repair	Achilles Tendon Repair
Position	Supine	Prone
Incision	Over tendon	⇐
Special instrumentation	Wire or synthetic tape for augmentation	⇐
Unique considerations	Tourniquet	⇐
Antibiotics	Cefazolin 1 g iv (vancomycin or clindamycin if penicillin allergic)	⇐
Surgical time	1 h	⇐
Closing considerations	Splint or cast while anesthetized	⇐
EBL	Minimal	⇐
Postop care	PACU → room or home	⇐
Mortality	Minimal	⇐
Morbidity	Weakness: ~10%	⇐
	Wound slough: 5%	⇐
	Adhesions: < 1%	⇐
	Infection: < 1%	⇐
	Rerupture: 5–10%
Pain score	3	3

P.1026

Patient Population Characteristics

Age range	Any age
Male:Female	1:1
Incidence	Uncommon
Etiology	Trauma (90%); chronic tendinitis (10%)
Associated conditions	Obesity; diabetes mellitus (DM); inflammatory arthritis

P.1027

Anesthetic Considerations for Knee Procedures

(Procedures covered: arthroplasty; arthrodesis; ORIF of patellar fractures; repair/reconstruction of ligaments; patellar realignment; arthroscopy; arthrotomy; tendon repair—knee and leg)

Preoperative

Trauma and osteoarthritis (OA) are the most common indications for these procedures. Trauma patients (e.g., those with sports injuries) are often young and healthy, whereas arthritic patients are often elderly, and anesthetic management must be tailored to any concurrent disease. Patients with rheumatoid and other inflammatory arthritides form another group of candidates for these procedures; the special anesthetic considerations for these patients are described in Anesthetic Considerations for Hip Procedures, p. 997. A final group of patients undergoing these procedures are hemophiliacs, who develop arthritis from recurrent bleeding into their joints. The hematologic management of these patients is discussed below.

Respiratory	These patients often have rheumatoid arthritis and associated pulmonary conditions. For example, pulmonary effusions are common. Limited respiratory reserve warrants further evaluation. Pulmonary fibrosis (rare) often manifests as a cough and dyspnea. Rheumatoid arthritis involving the cricoarytenoid joints may manifest as hoarseness, glottic narrowing, and difficult intubation. Arthritic involvement of the TMJ and cervical spine may further complicate airway management. Tests: As indicated from H&P.
Cardiovascular	The severity of the arthritis often limits exercise and makes assessment of cardiovascular status difficult. Dobutamine stress ECHO, and dipyridamole thallium imaging may be necessary for an adequate cardiac evaluation. Rheumatoid arthritis is associated with pericardial effusion, cardiac valve fibrosis, cardiac conduction abnormalities and aortic regurgitation (AR). Tests: ECG and others as indicated from H&P.
Neurological	In arthritic patients, a thorough preop neurological exam often yields evidence of cervical nerve root compression. After the stability of the neck has been established, the full range of neck motion should be evaluated for evidence of nerve compression or cerebral ischemia (suggesting vertebral artery compression). Consider preop lateral neck films to determine stability of atlantooccipital joint and evidence of vertebral spurs that may interfere with intubation. Tests: As indicated from H&P.
Musculoskeletal	Pain and ↓ joint mobility may make positioning and regional anesthesia difficult in this patient population.
Hematologic	Hemophiliacs require restoration of clotting factors preop. Administer 1 U of factor concentrate/kg body weight for each 2% increase necessary to achieve clotting factor activity of 40% normal. FFP contains l U/mL and cryoprecipitate 20 U/mL. Hemophilia B (Factor IX deficiency), but not hemophilia A (Factor VIII deficiency), can be treated with prothrombin complex concentrate; however, these products can activate clotting factors and → DIC. Approximately 10% of hemophiliacs develop antibodies to exogenous clotting factors, and the care of these patients should be guided by a hematologist. Tests: Hct; other tests as indicated from H&P.
Laboratory	Other tests as indicated from H&P.
Premedication	Standard premedication (see p. B-1). Preop patellar pain is treated effectively with a femoral nerve block at the inguinal ligament, using 10 mL of lidocaine 1.5% with epinephrine 1:200,000.

Intraoperative

Anesthetic technique: For many of these patients, regional anesthesia may be the preferred technique, offering the advantages of ↓ blood loss, ↓ DVT, minimal respiratory impairment, and effective postop analgesia. Patients with rheumatoid arthritis rarely have involvement of the lumbar spine. Because rheumatoid arthritis frequently affects the C-spine, however, these patients may have limited range of neck motion, an unstable atlantooccipital joint, and cricoarytenoid and TMJ arthritis. Careful airway evaluation, therefore, is important to determine the appropriateness of special intubation techniques (e.g., fiber optic).

Regional anesthesia: A continuous peripheral nerve block (CPNB) provides similar effect on postop length of hospital stay and rehabilitation compared to an epidural pain management but has a lower incidence of side effects (urinary retention, hypotension, and dysesthesia). A combined femoral and sciatic nerve block provides superior pain control in the first 36 postoperative hours over a single, femoral nerve block. In addition to the nerve block, either a GA or a SAB is needed for the intraoperative phase since a CPNB does not reliably provide surgical anesthesia. Both nerves can be localized conventionally using a nerve stimulator or with ultrasound-guidance. A typical initial local anesthesia dose for each nerve is 20 mL of 0.5% bupivacaine or 0.75% ropivacaine.

An epidural block provides both intraop surgical anesthesia and postop pain control but it is contraindicated in patients receiving Coumadin postop. If the patient prefers not to receive a peripheral nerve or an epidural block, a subarachnoid block provides a useful alternative regional anesthesia technique, depending on the patient population (e.g., younger patients may be at ↑ risk of spinal headache following SAB). Anesthesia extending from S2 to T12 (T8, if tourniquet is used) is adequate for knee surgery. Full motor blockade is essential for fixation of the patella, or placement of the joint prosthesis and assessment of the passive ROM of the prosthesis. Typical drugs and doses include: subarachnoid—12.5–15 mg of 0.75% bupivacaine with morphine 0.2 mg; epidural—15–20 mL 2% lidocaine with epinephrine 1:200,000 in divided doses.

General anesthesia:

Induction		Standard induction (see p. B-2) is appropriate for patients with normal airways.
Maintenance		Standard maintenance (see p. B-2). Neuromuscular relaxation facilitates the placement of the prosthesis. Hemophiliacs will require infusion of clotting factors. For hemophilia A and von Willebrand's disease, 1.5 U/kg/h; for hemophilia B, 0.75 U/kg/h.
Emergence		The tourniquet is deflated around the time of emergence. In patients with moderate-to-severe lung disease, controlled ventilation should be continued until after the lactic acid that has accumulated in the leg has been metabolized (3–5 min), because these patients may be unable to increase ventilation to buffer this acid load.
Blood and fluid requirements	IV: 14–16 ga × 1 NS/LR @ maintenance during the case, and 5–10 mL/kg bolus prior to tourniquet deflation	A tourniquet blocks intraop blood loss. When it is deflated, prepare for a 1–2 U blood loss over the ensuing h; more if the posterior tibial artery has been damaged in the dissection. Avoid under-resuscitation.
Control of blood loss	Tourniquet	Inflation pressure is typically 100 mmHg + systolic pressure. Maximum tourniquet time is 2 h, followed by a 30 min reperfusion interval, if further tourniquet time is necessary.
Monitoring	Standard monitors (see p. B-1).
	± CVP line	A CVP line is indicated if monitoring the CVP trend is expected to affect anesthetic care.
	± Arterial line	Additional monitoring (CVO2Sat, PA cath, TEE) may be indicated in special cases.
Positioning	[check mark] and pad pressure points. [check mark] eyes.	In rheumatoid arthritic patients, meticulous padding of the extremities is mandatory.
Complications	Posterior tibial artery trauma Peroneal nerve palsy	A 20% ↓MAP is common on tourniquet deflation. Additional crystalloid (5–10 mL/kg) may be necessary to replace edema fluid and blood loss to the leg.

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Postoperative

Complications	Hemorrhage from the posterior tibial artery	[check mark] surgical drain output.
	Peroneal nerve palsy → foot drop	Examine patient for evidence of neurologic dysfunction and notify surgeons as necessary.
	Tourniquet-related nerve injury
	Post-tourniquet syndrome (PTS)	PTS is a self-limiting condition in which the affected limb is edematous, pale, and weak.
Pain management	Neuraxial regimens:
	· Epidural anesthesia	Epidural bupivacaine 0.0125% infused at 6–8 mL/h with hydromorphone 50 mcg/mL infused at 100–250 mcg/h provides good analgesia. Prior to removal of the epidural catheter a 0.2 mg bolus of hydromorphone may be given. Epidural catheters are typically removed on the morning of postop day 2. Low-molecular-weight heparin may be started 2 h after catheter removal.
	· SAB	Intrathecal morphine 0.2–0.3 mg provides analgesia for up to 24 h. May be administered along with bupivacaine for surgical anesthesia.
	Peripheral regimens:
	· Single-shot peripheral nerve block (femoral or combined femoral/sciatic block)	These nerves may be blocked preop or postop as a pain rescue measure. A typical dose for each nerve is 20 mL of 0.5% bupivacaine or 0.75% ropivacaine.
	· CPNB Systemic regimens:	Continuous infusion of bupivacaine 0.125% through a standard infusion pump or a portable/disposable pump. Foley catheters are not required with peripheral nerve catheters. Oral pain management with acetaminophen should be initiated immediately postoperatively (if not contraindicated). Patient-controlled analgesia (PCA) with IV morphine or hydromorphone may be initiated as alternative to neuraxial blocks or to supplement peripheral regimens.
Tests	Hct; other studies as indicated.	Patients with coagulopathies require replacement therapy for 6–10 d.

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Suggested Readings

1. Choi PT, Bhandari M, Scott J, et al: Epidural analgesia for pain relief following hip or knee replacement. Cochrane Database Syst Rev2003; 3:CD003071.
2. Epps CH Jr, ed: Complications in Orthopaedic Surgery,3rd edition. JB Lippincott, Philadelphia: 1994.
3. Fowler SJ, Symons J, Sabato S, et al: Epidural analgesia compared with peripheral nerve blockade after major knee surgery: a systematic review and meta-analysis of randomized trials. Br J Anaesth2008; 100(2):154–64.
4. Kuper M, Rosenstein A: Infection control in total knee and total hip arthroplasties. Am J Orthop2008; 37(1):E2–5.
5. Rosenberg AG: Anesthesia and analgesia protocols for total knee arthroplasty. Am J Orthop2006; 35(7 Suppl):23–6.
6. Scuderi GR: Preoperative planning and perioperative management for minimally invasive total knee arthroplasty. Am J Orthop2006; 35(7 Suppl):4–6.