Pediatric Orthopedic Surgery

James G. Gamble MD, PhD¹

Amy L. Ladd MD¹

Genevieve D’Souza MD²

Brenda Golianu MD²

R. J. Ramamurthi MD, FRCA²

¹SURGEONS

²ANESTHESIOLOGISTS

PERCUTANEOUS PINNING OF DISPLACED SUPRACONDYLAR HUMERUS FRACTURE

SURGICAL CONSIDERATIONS

Description: Supracondylar fractures of the humerus are the most common elbow fractures in children and the most common pediatric fractures requiring reduction under GA. They have a justifiable reputation for complications because of the risk to the brachial artery and a high incidence of median or radial nerve palsies. The most serious potential complication is a compartment syndrome of the forearm, resulting in the need for emergency reduction and fasciotomy.

The vast majority of these injuries result from falling on an outstretched arm with the elbow extended—a extremely common childhood event. Type 1 supracondylar fractures are minimally displaced and usually stable. They can be managed with a splint alone. Most supracondylar fractures are either Type 2 or Type 3 completely displaced fractures and require general anesthesia for closed reduction and percutaneous pinning.

Flexion-type supracondylar fractures are more likely to require open reduction than extension-type injuries.

Documentation of the neurovascular examination is mandatory immediately before anesthesia and upon awakening. When a patient appears in the emergency department, if the neurovascular status is normal, and if the patient has eaten recently, it may be safe to wait 6-8 h with continued monitoring of the neurovascular status. Reduction is obtained by a combination of traction and manipulation. Complete muscular relaxation is essential during the reduction maneuver. Usually two small smooth Kirschner wires are inserted under fluoroscopic control. Many surgeons prefer to use the intensifier screen as a platform; thus requiring the patient to be at the edge of the OR table. Occasionally, the fracture cannot be reduced closed, and an open reduction is necessary. In that case, the arm is reprepped, and a small, lateral incision is made to openly visualize and reduce the fracture. The same type of smooth pin fixation is then used. Prolonged skeletal traction, although used in the past, is rarely used, and the standard of care is reduction and percutaneous pinning. Following the pinning, either a splint or well-padded cast is applied before the patient is awakened.

Figure 12.7-1. Percutaneous pinning of supracondylar humerus fracture. A: The fracture is manually reduced and held with elbow flexed. B: Fracture reduction is assessed with I.I. C: The fracture is stabilized with percutaneous K-wires. (Reproduced with permission from Chapman MW: Chapman’s Orthopaedic Surgery, 3rd edition. Lippincott Williams & Wilkins, Philadelphia: 2001.)

Usual preop diagnosis: Supracondylar fracture of the elbow

▪ SUMMARY OF PROCEDURES

	Percutaneous Pinning	Open Reduction
Position	Usually supine, occasionally prone or lateral	⇚
Incision	None	1″ lateral
Special instrumentation	Power drill, image intensifier, or FluoroScan	⇚
Unique considerations	Full stomach; impending compartment syndrome	⇚
Antibiotics	Usually none	Cefazolin 25 mg/kg
Surgical time	30-60 min	30-90 min
Closing considerations	Cast or splint	⇚
EBL	Minimal	⇚
Postop care	PACU → room; close neurovascular monitoring	⇚
Mortality	Rare	⇚
Morbidity	Late angular deformity, especially cubitus varus: 10% Nerve palsy (typically radial nerve) from the fracture itself: 7% Compartment syndrome (Volkmann’s contracture): < 0.5% (some degree of vascular spasm or loss of radial pulse much more common) Stiffness, myositis ossificans Ipsilateral fracture	⇚ ⇚ ⇚ ⇚ ⇚
Pain score	3-5	3-6

ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Upper-Extremity Procedures, see p. 1393.

Suggested Readings

1. Franklin CC, Skaggs DL: Approach to the pediatric supracondylar humeral fracture with neurovascular compromise. Instr Course Lect 2013; 62:429-33.

2. Georgopoulos G, Carry P, Pan Z, Chang F, Heare T, Rhodes J, et al: The efficacy of intra-articular injections for pain control following the closed reduction and percutaneous pinning of pediatric supracondylar humeral fractures: a randomized controlled trial. J Bone Joint Surg Am 2012; 94:1633-42.

3. Gordon JE, Patton CM, Luhmann SJ, et al: Fracture stability after pinning of displaced supracondylar distal humerus fractures in children. J Pediatr Orthop 2001; 21(3):313-8.

4. Kasser JR, Beaty JH: Supracondylar fractures of the distal humerus. In: Beaty JH, Kasser JR, eds. Fractures in Children. Lippincott-Raven, Philadelphia: 2001;577-624.

5. Mehan ST, May CD, Kocher MS: Operative management of displaced flexion supracondylar humerus fractures in children. J Pediatr Orthop 2007; 27:551-6.

6. Mehlman CT, Strub WM, Roy DR, et al: The effect of surgical timing on the perioperative complications of treatment of supracondylar humeral fractures in children. J Bone Joint Surg Am 2001; 83A(3):323-7.

7. Mulpuri K, Wilkins K: The treatment of displaced supracondylar humerus fractures: evidence-based guideline. J Pediatr Orthop 2012; 32 (Suppl 2):143-52.

CLOSED OR OPEN REDUCTION OF DISPLACED LATERAL CONDYLE HUMERUS FRACTURE

SURGICAL CONSIDERATIONS

Description: Lateral condylar fractures of the distal humerus are second only to supracondylar fractures in frequency. Initial radiographs of lateral condyle fractures can look deceptively normal; however, because these fractures cross the physis (growth plate) and enter the articular surface, they require anatomic reduction to restore joint surface congruity and to avoid a premature physeal arrest. In addition, the elbow may be unstable and dislocate if the fracture extends into the trochlea of the humerus. Accurate and stable reduction minimizes the risk of nonunion, a well-known complication resulting from unsuspected rotation of the fracture fragment and by traction forces of the extensor muscles attaching to this condyle. Unlike supracondylar fractures, neurovascular complications are rare with lateral condyle fractures.

Although minimally displaced fractures can be treated with a cast, 60% of lateral condyle fractures are displaced and require manipulation and pinning. Casting without manipulation, and thus requiring no anesthesia, is indicated for stable fractures that are displaced < 2 mm. Closed reduction and percutaneous pinning under fluoroscopic control requires general anesthesia and is indicated for stable fractures with 2-4 mm displacement. Open reduction and pinning is necessary for fractures that are unstable, rotated, or displaced more than 4 mm. Muscular relaxation is advantageous when performing either a closed or open reduction of the fracture. A sterile tourniquet is used for cases requiring open reduction.

Usual preoperative diagnosis: Displaced lateral condyle humerus fracture

▪ SUMMARY OF PROCEDURES

	Closed Reduction/Pinning	Open Reduction/Pinning
Position	Supine	⇚
Incision	None	1-2″ lateral
Instrumentation	Power drill, fluoroscopy	⇚
Unique considerations	None	⇚
Antibiotics	Usually none	Cefazolin 25 mg/kg
Surgical time	30-60 min	45-90 min
Closing considerations	Cast or splint	⇚
EBL	Negligible	⇚
Postoperative care	PACU → room	⇚
Mortality	Rare	⇚
Morbidity	Delayed or nonunion Cubitus valgus (more common) or varus Lateral condylar overgrowth Physeal arrest Osteonecrosis of lateral trochlea Ulnar nerve palsy	⇚ ⇚ ⇚ ⇚ ⇚ ⇚ Avascular necrosis of trochlea
Pain score	3-5	3-6

ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Upper-Extremity Procedures, see p. 1393.

Suggested Readings

1. Beathy JH: Fractures of the lateral humeral condyle are the second most frequent elbow fracture in children. J Prthop Trauma 2010; 24:434-8.

2. Launay F, Leet AI, Jacopin S, et al: Lateral humeral condyle fractures in children: a comparison of two approaches to treatment. J Pediatr Orthop 2004; 24:385-91.

3. Song KS, Water PM: Lateral condyle humerus fractures: which one should we fix? J Pediatr Orthop 2012; 32 (Suppl 1):S5-9.

4. Thomas DP, Howard AW, Cole WG, et al: Three weeks of Kirschner wire fixation for displaced lateral condylar fractures of the humerus in children. J Pediatr Orthop 2001; 21(5):565-9.

ASPIRATION AND INJECTION OF UNICAMERAL BONE CYST

SURGICAL CONSIDERATIONS

Description: Unicameral bone cysts (UBCs) are benign lesions typically located in the metaphyseal regions of long bones, most commonly in the proximal humerus of a growing child. The cyst is rarely a source of pain until presentation (typically after a fracture). The benign radiographic appearance allows clinicians to follow most lesions without the need for surgical biopsy. Surgical care is indicated when the UBC is of sufficient size and location to cause mechanical weakening of the bone and predispose to a pathologic fracture. The goals of surgical care are to confirm the diagnosis of UBC and to reestablish the mechanical integrity of the bone. Diagnosis of a UBC is made by percutaneous aspiration of the lesion, using a standard 16- to 18-gauge spinal needle under general anesthesia. Fluoroscopic guidance facilitates needle placement. The presence of clear, straw-colored fluid confirms diagnosis of UBC. An alternative diagnosis, such as aneurismal bone cyst, is more likely if frank blood is aspirated. If the lesion contains no fluid, it may be a nonossifying fibroma.

Open biopsy may be necessary if the diagnosis is unclear. However, most cases can be treated adequately with percutaneous aspiration and injection of a radiopaque dye to verify that the entire cavity is contiguous. If the cystic cavity is loculated by bony trabecula, a curette or percutaneous Kirschner wire is used to convert the lesion into a unicompartmental space so the subsequent injection will easily access the entire lesion. Scraping the inner cyst walls also helps to disrupt the cyst lining and is thought to improve the chance of filling in the cavity. The final surgical step
is to introduce a second “venting” needle into the cyst to allow lavage with sterile saline, followed by injection of the cavity with a substance to promote new bone formation. Historically, methylprednisolone has been used, but more recent evidence suggests a higher success rate when autologous bone marrow is injected. Injectable allograft bone preparations also can supplement the bone marrow injection. Care must be taken to avoid aspirating from the first needle after the second has been placed, to avoid intraosseous air embolism.

Usual preoperative diagnosis: Unicameral bone cyst

▪ SUMMARY OF PROCEDURES

	Percutaneous	Open
Position	Supine	⇚
incision	None	Length of cyst
Instrumentation	Spinal needles, Kirschner wires, I.I.	Curettes
Unique considerations	Risk of air embolus	Additional time for intraop pathology evaluation
Antibiotics	Usually none	Cefazolin 25 mg/kg
Surgical time	30-60 min	60-90 min
Closing considerations	None	Cast or splint
EBL	Minimal	⇚
Postop care	PACU → home	PACU → room/home
Mortality	Rare	⇚
Morbidity	Infection Iatrogenic fracture Growth arrest: rare	⇚ ⇚ ⇚
Pain score	0-2	3-6

▪ PATIENT POPULATION CHARACTERISTICS

Age range	5-15 yr; not found in adults
Male:Female	1:3
Incidence	20% of benign bone lesions; most common location is the proximal humerus (67%), followed by the proximal femur (15%)
Etiology	Unknown. Venous obstruction → fluid transudate containing high levels of interleukin-1 and interleukin-6, which stimulate osteoclasts
Associated conditions	Usually normal, healthy child. Initial presentation typically follows a pathologic fracture.

ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Upper-Extremity Procedures, see p. 1393.

Suggested Readings

1. Alvarez RG, Arnold JM: Arthroscopic assistance in minimally invasive curettage and bone grafting of a calcaneal unicameral bone cyst. Foot Ankle Int 2007; 28:1198-9.

2. Rougraff BT, Kling TJ: Treatment of active unicameral bone cysts with percutaneous injection of demineralized bone matrix and autogenous bone marrow. J Bone Joint Surg 2002; 84A(6):921-9.

RELEASE FOR TORTICOLLIS

SURGICAL CONSIDERATIONS

Description: Congenital muscular torticollis is a painless tilting of the head due to contracture of the sternocleidomastoid muscle. The head tilts toward the involved side and rotates toward the opposite side (a “cock-robin” posture such that the chin points to the opposite side). It is associated with breech and difficult deliveries, as well as other musculoskeletal disorders, such as metatarsus adductus, hip dysplasia, and talipes equinovarus. Multiple theories regarding the etiology of congenital muscular torticollis have been proposed, including fibrosis of the sternocleidomastoid muscle following a peripartum intramuscular bleed, fibrosis resulting from a compartment syndrome of the sternocleidomastoid muscle, intrauterine crowding, and a primary myopathy of the sternocleidomastoid muscle. Eighty percent of cases of torticollis are a result of this congenital contracture of the sternocleidomastoid muscle. Less common etiologies—such as congenital cervical spine malformations (e.g., Klippel-Feil syndrome), neurologic disorders, a cranial or cervical neoplasm, inflammatory conditions (e.g., Grisel’s syndrome), or an ocular dysfunction—should also be excluded. Congenital muscular torticollis is seen more frequently on the right side. A persistent torticollis will lead to skull and facial deformities (plagiocephaly). If the child sleeps prone, he will usually lie with the affected side down, resulting in flattening of the face on that side. If the child sleeps supine, flattening of the contralateral skull occurs. This plagiocephaly will become permanent if the torticollis persists and is left untreated.

Initial treatment includes physical therapy for stretching exercises. For children < 1 yr of age, a program of sternocleidomastoid muscle stretching is recommended, with 90% of cases being resolved with this treatment. After 2 yr of age, nonoperative treatment is not likely to be effective. Children with persistent torticollis and an unacceptable amount of facial asymmetry preferably are treated surgically before the age of 3 yr; however, some improvement in facial asymmetry has been shown even in children surgically treated up to 8 yr of age.

Surgical options include a unipolar release, a bipolar release, middle-third transection, or a complete resection. Unipolar release involves division of the distal insertion of the sternocleidomastoid muscle and usually is performed for a mild deformity. Bipolar release entails division of both the sternocleidomastoid origin and insertion and usually is done for more marked involvement. Z-plasty of the clavicular head or transfer of the clavicular head to the sternal head may be done to maintain a more normal cosmetic contour of the neck. Potential surgical complications include injury to the spinal accessory nerve, jugular veins, carotid vessels, and the facial nerve. Postop, patients may perform simple stretching exercises, but they often require bracing to maintain a corrected alignment.

Usual preoperative diagnosis: Congenital muscular torticollis

▪ SUMMARY OF PROCEDURES

	Unipolar	Bipolar
Position	Supine	⇚
Incision	Transverse, 1.5 cm superior to sternum and clavicle over muscle insertion	⇚ + 1 cm distal to mastoid process behind ear at muscle origin
Unique considerations	Plagiocephaly	⇚
Antibiotics	Cefazolin 25 mg/kg	⇚
Surgical time	30 min	45 min
EBL	Minimal	⇚
Postoperative care	PACU → room/home	⇚
Mortality	Rare	⇚
Morbidity	Hypertrophic scar Loss of normal muscle contour	⇚ ⇚ Spinal accessory nerve injury
Pain score	3-5	3-5

ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Upper-Extremity Procedures, see p. 1393.

Suggested Readings

1. Shim JS, Noh KC, Park SJ: Treatment of congenital muscular torticollis in patients older than 8 years. J Pediatr Orthop 2004; 24:683-8.

2. Von Heideken J, Green DW, Burke SW, et al: The relationship between developmental dysplasia of the hip and congenital muscular torticollis. J Pediatr Orthop 2006; 26:805-8.

POLLICIZATION OF A FINGER

SURGICAL CONSIDERATIONS

Description: This procedure is indicated in the infant with congenital absence or hypoplasia of the thumb. A normal finger—usually the index finger—with its tendon, nerve, and vascular supply is shortened and rotated into the position of the thumb (Fig. 12.7-2). Tendon transfers are performed to substitute for the absent or hypoplastic thenar muscles. These patients may have many other associated congenital anomalies, which should be ruled out prior to surgery.

Variant procedure or approaches: There are several different surgical techniques, which share the basic transposition and rotation of the finger to the thumb position.

Usual preop diagnosis: Aplastic thumb; hypoplastic thumb; radial club hand; radial longitudinal deficiency

▪ SUMMARY OF PROCEDURE

Position	Supine, with arm extended on hand surgery table
Incision	Multiple incisions on the hand
Special instrumentation	Pneumatic tourniquet; magnification loupes
Antibiotics	Cefazolin 25 mg/kg (children)
Surgical time	3-4 h
Tourniquet	100 mm Hg above systolic; max time = 120 min
Closing considerations	Complex skin flaps are necessary. A plaster splint is placed while the patient is still anesthetized.
EBL	Minimal; performed under tourniquet control.
Postop care	PACU → overnight admission for observation or perfusion to the transposed finger
Mortality	Minimal
Morbidity	Ischemia (loss of digit): Rare Skin flap necrosis: Moderately common
Pain score	1-2

Figure 12.7-2. Pollicization of a finger. (Reproduced with permission from Chapman MW: Chapman’s Orthopaedic Surgery, 3rd edition. Lippincott Williams & Wilkins, Philadelphia: 2001.)

▪ PATIENT POPULATION CHARACTERISTICS

Age range	1-2 yr is ideal time for surgery. Procedure should be done before patient begins school.
Male:Female	1:1
Incidence	Overall, about 1/20,000 live births require a variant of this procedure.
Etiology	Unknown; also associated with thalidomide ingestion.
Associated conditions	Associated congenital anomalies of the upper extremity, esophagus, spine, and lower extremities Absence of radius (radial club hand), common Various forms of syndactylies, common Abnormalities of the hematopoietic system (Fanconi’s syndrome), cardiovascular system (ASDs in Holt-Oram syndrome), spine, and GI system, along with hypothyroidism, are frequently associated.

ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Upper-Extremity Procedures, see p. 1393.

SYNDACTYLY REPAIR

SURGICAL CONSIDERATIONS

Description: Syndactyly refers to congenital failure of separation of two or more fingers. It is complete if it extends to the ends of the fingers; incomplete syndactyly extends short of the finger ends. A simple syndactyly repair joins fingers by only skin and fibrous tissues. A complex syndactyly repair signifies fusion of adjacent phalanges or interposition of accessory phalanges, with frequent abnormalities of the neurovascular structures. Surgical separation is performed in the first few years of life for functional as well as aesthetic reasons. The technique involves creation of a dorsal, proximally based skin flap to recreate the web. A zigzag dorsal and palmar incision is then created, separating from the distal end in a proximal direction. The digital nerve and arteries are dissected proximally as far as possible. Primary closure is almost never possible, and supplemental full-thickness skin graft harvested from the groin is used to complete the closure. Usually only one site is done at a time per hand, and never should both sides of a digit be released because of risk to the vascular supply. It is not always possible to save all the bony elements. Patients with conditions such as Apert syndrome must undergo careful evaluation of the airway.

Usual preop diagnosis: Syndactyly of fingers; bifid finger, thumb/finger

▪ SUMMARY OF PROCEDURE

Position	Supine
incision	Zigzag between digits; skin graft donor site from groin
Special instrumentation	Magnification loupes always necessary. Tourniquet is mandatory.
Unique considerations	Groin skin also must be taken for graft closure.
Antibiotics	Usually none
Surgical time	2-4 h
Closing considerations	Above-the-elbow cast or splint to keep incision away from mouth and other hand of the infant or child
EBL	20 mL
Postop care	PACU → home, if simple syndactyly
Mortality	None associated with procedure.
Position	Supine

ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Upper-Extremity Procedures, see p. 1393.

Suggested Readings

1. Bauer TB, Tondra JM, Trusler HM: Technical modification in repair of syndactylism. Plast Reconstr Surg 1956; 17:385-92.

2. Chang J, Danton TK, Ladd AL, et al: Reconstruction of the hand in Apert’s syndrome: a simplified approach. Plast Reconstr Surg 2002; 109(2):465-70.

3. Ecoffey C: Pediatric regional anesthesia—upper extremity blocks. In: Gregory GA, Andropoulos DB, eds. Pediatric Anesthesia, 5th edition. Wiley-Blackwell, Oxford: 2012, 431-4.

4. Lammers C, Wyckaert C: Anesthesia for orthopedic surgery. In: Gregory GA, Andropoulos DB, eds. Pediatric Anesthesia, 5th edition. Wiley-Blackwell, Oxford: 2012, 757-77.

5. Oda T, Pushman AG, Chung KC: Treatment of common congenital hand condition. Plast Reconstr Surg 2012; 126:121e-33e.

6. Smith GD: Congenital hand anomalies and reconstruction. Br J Hosp Med (Lond) 2012; 73:203-9.

7. Zuckerberg AL, Yaster M: Anesthesia for orthopedic surgery. In: Davis PJ, Cladis FP, Motoyama EK, eds. Smith’s Anesthesia for Infants and Children, 8th edition. Elsevier, Philadelphia: 2011, 842-69.

ANESTHETIC CONSIDERATIONS FOR UPPER EXTREMITY PROCEDURES

(Procedures covered: percutaneous pinning; displaced supracondylar humerus fracture; closed/open reduction; displaced lateral condylar humerus fracture; aspiration/injection unicameral/bone cyst; torticollis release; pollicization of finger; syndactyly release)

PREOPERATIVE

The majority of children presenting for repair of upper-extremity fractures are otherwise healthy. Most of these patients present for repair of a traumatic injury; thus, the preop workup is routine. Some arm procedures, such as repair of a compound fracture, require immediate attention and necessitate emergency surgery and full-stomach considerations (see p. B-5).

Laboratory	Tests as indicated from H&P
Premedication	Standard premedication (see p. D-1).

INTRAOPERATIVE

Anesthetic technique: GETA or LMA because children rarely tolerate regional anesthesia alone. In the older patient, regional anesthesia may be appropriate and can reduce the risk of aspiration pneumonitis associated with
GA in the patient with a full stomach. A combined technique offers the advantages of reduced anesthetic requirements and postop pain relief; however, regional anesthesia is relatively contraindicated in patients with neurovascular damage.

General anesthesia:

Induction	Standard induction (see p. D-1) except in acute trauma patients, where rapid-sequence induction is appropriate (see p. B-5).
Maintenance	Standard maintenance (see p. D-3).
Emergence	Management of emergence and extubation should be routine, except in difficult airway cases, which require awake extubation. Skin closure is frequently followed by application of a splint; patient should remain anesthetized during splinting procedure.

Regional anesthesia:

Ultrasound guidance: Ultrasound-guided nerve block techniques are increasingly used in pediatric anesthesia. The use of ultrasonography increases the ability to position the needle as close to the nerve as possible avoiding inadvertent trauma to the adjacent structures. Direct visualization also helps in optimizing the volume and distribution of the local anesthetic thus improving the safety and efficacy of the block.

Anesthetics and doses	See Table 12.7-1.
Interscalene block	Performed at levels of C6 to minimize risk of pneumothorax. The phrenic nerve lies anterior to the brachial plexus and is frequently blocked by anterior spread of LA, leading to hemidiaphragm paralysis. This is usually well tolerated; however, care must be taken in patients with respiratory compromise. Temporary Horner’s syndrome may result from LA migration to sympathetic chain. Major complications (e.g., total spinal or pneumothorax) resulting from interscalene block are very rare; therefore, this technique is suitable for outpatients. Interscalene block is contraindicated in patients with contralateral recurrent laryngeal nerve palsy.
Infraclavicular block	The infraclavicular approach to brachial plexus block has the advantage of blocking the axillary and musculocutaneous nerves. The coracoid approach is shown to be safer than the classical approach. Use of ultrasonography increases the efficacy and safety of this block.
Axillary block	The medial aspect of the upper arm is innervated by the intercostobrachial nerve (T2) and requires a separate subcutaneous field block in the axilla, especially when a tourniquet is used. The lateral cutaneous nerve of the forearm, a sensory branch of the musculocutaneous nerve supplying sensation to the lateral forearm, is frequently missed by the axillary approach to the brachial plexus. Thus, a block of this nerve at the elbow is sometimes necessary. The maximum recommended doses for local anesthetics are shown in Table 12.7-1.
Supplemental sedation	Supplemental sedation may be accomplished with use of propofol by continuous infusion (50-150 mcg/kg/min).
Blood and fluid requirements	Minimal blood loss IV: 22 ga × 1 NS/LR @ 4-2-1 rule maintenance	IV catheter should be placed in the contralateral upper extremity.
Monitoring	Standard monitors (see p. D-1).
Positioning	[check mark] and pad pressure points [check mark] eyes

Table 12.7-1. Maximum Recommended Doses of Anesthetics for Regional Anesthesia

Drug	*mg/kg (with epinephrine)**	Duration (min)
Lidocaine	5 (*7)	45-180
Bupivacaine	2.5 (*3)	180-600
Ropivacaine	3	180-600
Tetracaine	1.5	180-600
2-Chloroprocaine	8 (*10)	30-60
Procaine	8 (*10)	60-90

Interscalene block complications

Total spinal

Epidural anesthesia

IV injection (Sz/dysrhythmias)

Stellate ganglion block (Horner’s syndrome)

Laryngeal nerve block

Phrenic nerve block

Pneumothorax

Resuscitative equipment, including airway management tools, and intralipid should be immediately available. Dose of 20% intralipid: 1 mL/kg repeat × 2 max 3 mL/kg; infusion rate 0.25 mL/kg/min.

Infraclavicular block complications

Hematoma

Pneumothorax

Inadvertent intravascular injection

The coracoid approach has reduced risk of complications.

Axillary block complications

Inadequate block

Intravascular injection

Peripheral nerve damage

Axillary hematoma

Axillary artery thrombosis

Pneumothorax

Very minimal doses of local anesthetic can cause CNS toxicity if reverse flow occurs during an intra-arterial injection. Axillary thrombosis and pneumothorax are extremely rare.

POSTOPERATIVE

Pain management

PCA (see p. E-4).

Regional block

Combined regional-GA provides excellent postop pain management.

Tests

None routinely indicated.

Suggested Readings

1. Ecoffey C: Pediatric regional anesthesia—upper extremity blocks. In: Gregory GA, Andropoulos DB, eds. Pediatric Anesthesia, 5th edition. Wiley-Blackwell, Oxford: 2012, 431-4.

2. Lammers C, Wyckaert C: Anesthesia for orthopedic surgery. In: Gregory GA, Andropoulos DB, eds. Pediatric Anesthesia, 5th edition. Wiley-Blackwell, Oxford: 2012, 757-77.

3. Marhofer P, Greher M, Kapral S: Ultrasound guidance in regional anaesthesia. Br J Anaesth 2005; 94(1):7-17.

4. Marhofer P, Invani G, Suresh S, Melman E, Zaragoza G, Bosenberg A: Everyday regional anesthesia in children. Pediatr Anesth 2012; 22(10):995-1001.

5. Marhofer P, Sitzwohl C, Greher M, et al: Ultrasound guidance for infraclavicular brachial plexus anesthesia in children. Anaesthesia 2004; 59:642-6.

6. Surech S, Wheeler M: Practical pediatric regional anesthesia. Anesthesiol Clin North Am 2002; 20(1):83-113.

POSTERIOR SPINAL INSTRUMENTATION AND FUSION

SURGICAL CONSIDERATIONS

Description: Posterior spinal instrumentation refers to implanted metal rods affixed to the spine to correct and internally splint the deformed spine. Originally designed for scoliosis, posterior spinal instrumentation is commonly performed simultaneously with spinal fusion for a variety of diagnoses, including fracture, tumor, degenerative changes, and developmental spinal deformity. Although posterior spinal instrumentation with the ratcheted Harrington rod gained widespread usage in the 1970s, it is no longer used by spinal surgeons. The current standard is a hook-rod system, such as the Cotrel-Duboussett (C-D), the Texas Scottish Rite Hospital (TSRH), the Miami Modular Orthopaedic Spinal System (MOSS), and the Universal Spine System (USS). Regardless of the surgeon’s choice of instrumentation, the spine is approached by an extensive midline posterior incision, in which a subperiosteal exposure (typically T2-5 down to L1-4) is used to elevate all the paraspinous muscles as far laterally as the tips of the transverse processes. Typically, 4-8 hooks are affixed to the posterior spinal elements (lamina, pedicles, or transverse processes) on both the concave and convex sides of the spine (Fig. 12.7-3). These points of spinal fixation are then joined to two contoured rods. By compressing along the convex surfaces and distracting along the concave surfaces, some degree of rotational correction is possible. Some spine surgeons advise the patient to wear a brace for the initial months following surgery; however, body casts are no longer necessary.

Sublaminar wire loops (Fig. 12.7-4) are commonly used instead of the hook-rod method of spinal instrumentation when treating neuromuscular spinal deformity (e.g., cerebral palsy, muscular dystrophy, myelomeningocele, or spinal muscular atrophy). This alternative construct provides more points of fixation to the spine and eliminates the need for postop bracing. When a large degree of pelvic obliquity is a component of the patient’s deformity, the instrumentation often is extended into the iliac wings (Fig. 12-7.5).

Somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) are used routinely in centers where spinal deformity correction surgery is common. Close coordination among the surgeon, spinal cord monitoring personnel, and anesthesiologist is necessary to properly recognize adverse intraop spinal events and to minimize the occurrence of false-positive findings. Many spine surgeons also request that an intraop wake-up test be performed to further verify spinal cord function.

Figure 12.7-3. Placement of a standard pedicle hook, in a hood-rod device. (Reproduced with permission from Chapman MW, ed: Operative Orthopaedics, 3rd edition. Lippincott Williams & Wilkins, Philadelphia: 2001.)

Figure 12.7-4. An example of passing and attaching sublaminar wires. (Reproduced with permission from Chapman MW, ed: Operative Orthopaedics, 3rd edition. Lippincott Williams & Wilkins, Philadelphia: 2001.)

Figure 12.7-5. Positioning rods in pelvis; sublaminar wires being tightened. (Reproduced with permission from Chapman MW, ed: Operative Orthopaedics, 3rd edition. Lippincott Williams & Wilkins, Philadelphia: 2001.)

Usual preop diagnosis: Scoliosis (usually idiopathic or neuromuscular); kyphosis (increased round back); reconstruction for tumor, trauma, or other

▪ SUMMARY OF PROCEDURE

Position	Prone (on spinal frame or bolsters); avoid abdominal, elbow, and ocular compression.
Incision	Posterior midline; optional separate iliac crest bone graft
Special instrumentation	Rods, hooks, pedicle screws, wires
Unique considerations	“Wake-up” test and/or SSEPs; frequently, induced ↓ BP is requested; prolonged prone positioning places brachial plexus and ulnar nerve at risk.
Antibiotics	Cefazolin 1-2 g iv
Surgical time	2-6 h
Closing considerations	Greatest blood loss typically toward the end of procedure. Avoid hypotension after instrumentation is implanted.
EBL	1200-3000 mL
Postop care	ICU: 1-2 d
Mortality	0-0.5%
Morbidity	Acute ileus: very common Genitourinary infection: 5-7% Hematoma, massive bleeding: 1-5% Pneumothorax, pneumonia, atelectasis: 1-5% Hook dislodgement requiring reoperation: 0-2% Wound infection: 0-2% Superior mesenteric artery syndrome: 0-1% Thromboembolism: < 1% Spinal cord injury and/or root injury: 0.6% Delayed: Pseudarthrosis: 0-5% Late rod fracture: 0-5% Progression of spinal deformity: 0-2%
Pain score	7-9

▪ PATIENT POPULATION CHARACTERISTICS

Age range	Usually 8-40 yr
Male:Female	1:5
Incidence	1-2/10,000
Etiology	Idiopathic (50-75%); neuromuscular (20-30%); associated with syndromes such as osteochondral dystrophies, osteogenesis imperfecta, etc. (5%); congenital scoliosis (2-5%)
Associated conditions	Neuromuscular: Friedreich’s ataxia (myocarditis and other cardiovascular anomalies; sudden death) Myelomeningocele (latex allergy, chronic UTI, hydrocephalus) Muscular dystrophy (muscle weakness, cardiomyopathy, dysrhythmias, succinylcholine → prolonged muscle contraction, ↑ sensitivity to respiratory depressant effect of barbiturates, opiates, and benzodiazepines) Cerebral palsy (GERD, ↓ airway protective reflexes, ↑ postop pulmonary complications, malnourishment, Sz, medication may interfere with Plt function) Higher incidence of MH Connective tissue disease: Ehlers-Danlos and Marfan syndromes (avoid ↑ BP → aortic dissection; ↑ risk of pneumothorax). Osteogenesis imperfecta (position and intubate with great care). Congenital osteochondral dystrophies

ANESTHETIC CONSIDERATIONS

See Anesthetic Considerations for Spinal Reconstruction and Fusion, (see p. 997).

Suggested Readings

1. Abu-Kishk I, Kozer E, Hod-Feins R, et al: Pediatric scoliosis surgery—is postoperative intensive care unit admission really necessary? Paediatr Anaesth 2013; 23:271-7.

2. Auerbach JD, Lonner BS, Antonacci MD, et al: Perioperative outcomes and complications related to teaching residents and fellows in scoliosis surgery. Spine 2008; 33(10):1113-8.

3. Borgeat A, Blumenthal S: Postoperative pain management following scoliosis surgery. Curr Opin Anaesthesiol 2008; 21(3): 313-6.

4. Heller KD, Wirtz DC, Siebert CH, et al: Spinal stabilization in Duchenne muscular dystrophy: principles of treatment and record of 31 operative treated cases. J Pediatr Orthop 2001; 10(1):18-24.

5. Mathieseen O, Dahl B, Thomsen BA, et al: A comprehensive multimodal pain treatment reduce opioid consumption after multilevel spine surgery. Eur Spine J 2013; 22(9):2089-96.

6. Rusy LM, Hainsworth KR, Nelson TJ, et al: Gabepentin use in pediatric spinal fusion patients: a randomized, double-blind, controlled trial. Anesth Analg 2010; 110(5):1393-8.

7. Thomson JD, Banta JV: Scoliosis in cerebral palsy: an overview and recent results. J Pediatr Orthop 2001; 10(1):6-9.

8. Torre-Healy A, Samdani AF: Newer technologies for the treatment of scoliosis in the growing spine. Neurosurg Clin N Am 2007; 18(4):697-705.

ANTERIOR SPINAL FUSION FOR SCOLIOSIS

SURGICAL CONSIDERATIONS

Description: Anterior spinal fusion is performed through a transthoracic and/or retroperitoneal approach to the vertebral bodies, in which the intervertebral discs are removed and a bone graft is placed between the vertebral bodies. The disc removal (“release”) loosens the spine and allows greater deformity correction than posterior-only procedures. Often, no instrumentation is used anteriorly when the anterior fusion is performed as a first stage to a “front-and-back” fusion. (In such cases, posterior spinal instrumentation is subsequently implanted to correct the spinal deformity.) Anterior spinal instrumentation is performed when a posterior spinal fusion is not needed (e.g., idiopathic thoracolumbar or lumbar scoliosis).

When instrumentation of the anterior spine is performed, the surgical approach is through a flank incision, then through a rib bed on the convex side of the curve (usually the 10th rib). The retroperitoneal plane is entered and developed by blunt dissection behind the transversus abdominis muscle. The pleural cavity is entered, and the diaphragm usually must be divided circumferentially near its costal origin and around posteriorly to the spine. The prevertebral areolar plane is then entered and the segmental vessels to each vertebral body are clipped or cauterized in the midline. The psoas muscle is elevated off the lateral aspects of the vertebral bodies. Each disc in the fusion area (usually 3-5 discs) is excised back to the posterior longitudinal ligament. Next, vertebral screws (e.g., Texas Scottish Rite Hospital [TSRH], Miami Modular Orthopaedic Spine System [MOSS], Universal Spine System [USS] instrumentation) are inserted transversely across the appropriate bodies and joined at their heads by a rod (Figs. 12.7-6 and 12.7-7). Bone graft (typically from the rib harvested during the surgical approach) is placed within each discectomy level. A chest tube is placed before closure of the thoracic cavity.

Usual preop diagnosis: Idiopathic or neuromuscular scoliosis

Figure 12.7-6. Dwyer instrumentation used to make spinal correction. (Reproduced with permission from Crenshaw AH, ed: Campbell’s Operative Orthopaedics, 8th edition. Mosby-Year Book, St. Louis: 1992.)

Figure 12.7-7. Instrumentation from T10-L3 (Zielke). (Reproduced with permission from Chapman MW, ed: Operative Orthopaedics, 3rd edition. Lippincott Williams & Wilkins, Philadelphia: 2001.)

▪ SUMMARY OF PROCEDURES

	Fusion with Instrumentation	Release (No Instrumentation)
Position	Full lateral decubitus (Fig. 12.7-8)	⇚
Incision	Flank: over rib at top vertebra in the curve (usually T9-T11)	⇚
Special instrumentation	Screws, staples, rods	None
Unique considerations	Flex OR table at thoracolumbar junction until disc removal and deformity correction. Procedure often followed by posterior spinal fusion. Proximity of great vessels → potential for major bleeding. Patients with neuromuscular scoliosis often have poor generalized nutrition. SSEP/MEP often used to monitor spinal cord function.	⇚ Uninstrumented release is always followed by posterior spinal fusion with instrumentation.
Antibiotics	Cefazolin 25 mg/kg iv	⇚
Surgical time	3-4 h	2-3 h
Closing considerations	Chest tube always used; hypotension, if used electively, must be reversed before closure.	⇚
EBL	500-2000 mL	250-2000 mL
Postop care	ICU 1-2 d	⇚
Mortality	0-2%, depending on underlying conditions	⇚
Morbidity	Overall: 30%, depending on underlying condition Ileus and atelectasis: ˜50% UTI: 10-25% (common in spina bifida) Minor transient root weakness or paraesthesia: 10-20% Partial sympathectomy: common Late kyphosis above instrumentation: 5-10% Nonunion and hardware failure: 5% Massive blood loss: 2-5% Respiratory failure: 1-2% Pneumonia: 1% Paraplegia (acute anterior spinal artery syndrome): < 1% Thromboembolism: rare (< 5% in children)	20% ⇚ ⇚ 1-5% ⇚ – – ⇚ ⇚ ⇚ ⇚ ⇚
Pain score	5-8	4-7

Figure 12.7-8. Lateral decubitus position (diagrammatic) for anterior spinal procedures: (A) anterior view; (B) posterior view. Roll is placed under axilla to minimize axillary artery compression. Skin incision for exposure of T5-T12 is shown with the dotted line. (Reproduced with permission from Chapman MW, ed: Operative Orthopaedics, 3rd edition. Lippincott Williams & Wilkins, Philadelphia: 2001.)