the hip in cerebral palsy part 2 of 2

THE HIP IN CEREBRAL

PALSY

Topic presentation by

Dr. Libin Thomas Manathara

Amala Institute of Medical Sciences

Topics

• Introduction

• Flexion deformities

• Adduction deformities

• Adductor tenotomy

• Iliopsoas recession

• Iliopsoas release at the lesser trochanter

• Subluxation and Dislocation

• Varus derotational osteotomy

• San Diego procedure

• Proximal femoral resection

• Hip arthrodesis

• Total Hip Arthroplasty

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Subluxation and Dislocation• Hip dislocation occurs on a continuum from mild subluxation to true

dislocation with significant degenerative changes

• Early intervention can be very effective in preventing or delaying the

development of dislocation

• Clinically, a hip at risk has contractures of the ADductors and flexors

• Hips with flexion contractures of more than 20 degrees and ABduction ofless than 30 degrees are at increased risk of progressive subluxation

• Radiographically, a hip at risk has an increased neck-shaft angle andincreased femoral anteversion

• Acetabular dysplasia and an abnormal migration index also may be present

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Subluxation and Dislocation

•When a hip at risk is identified, a program of aggressive physical therapy andABduction splinting typically is started

•If further progression continues, early operative treatment consisting of softtissue release of contracted tendons is indicated

• The goal of ADductor release is restoration of more than 60 degrees ofABduction with the hips flexed and 45 degrees with the hips extended

•The release begins sequentially with

• complete release of the adductor longus,

• the anterior half of the adductor brevis, and

• occasionally the gracilis until the desired range of motion is achieved

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• Care must be taken not to perform too extensive a release, which can

cause an ABduction contracture that is extremely difficult to manage

• Rather than release, transfer of the adductors to the ischial tuberosity or

gracilis has been used to improve hip stability and prevent subluxation

• Hip subluxation occurs when more than one third of the femoral head is

uncovered and there is a break in the Shenton line

• In younger children, soft tissue releases alone may be sufficient, but most

patients with hip subluxation require osteotomy in addition to soft tissue

release

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Shenton line

• http://radiopaedia.org/articles/shenton-line (Dr Tim Luijkx and A.Prof Frank

Gaillard et al)

• Shenton line is an imaginary line drawn along the inferior border of the

superior pubic ramus (superior border of the obturator foramen) and along

the inferomedial border of the neck of femur

• This line should be continuous and smooth

• Interruption of the Shenton line can indicate (in the correct clinical scenario)

– developmental dysplasia of the hip (DDH)

– fractured neck of femur

• History and etymology

• The line was first described in 1902 by Edward Warren Hine Shenton (1872-

1955), an English radiologist

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Subluxation and Dislocation• Three-dimensional CT reconstructions often are helpful

• A femoral varus and derotation (external rotation) osteotomy (VDRO), oftencombined with femoral shortening, generally is used to reduce the neck-shaft angle to 115 degrees in ambulatory patients and often less innonambulatory patients

• A wide variety of acetabular osteotomies have been used in the treatment ofacetabular dysplasia in patients with cerebral palsy, including osteotomiesdescribed by Salter, Pemberton, Dega, Ganz, Steel and salvage-typeosteotomies such as the Chiari and shelf

• Postoperatively, patients can be immobilized for a brief time in a spica cast,followed by a period of aggressive rehabilitation that includes physicaltherapy, bracing, and progressive weight bearing

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Subluxation and Dislocation• Hip dislocation is common in patients with cerebral palsy, especially in

severely affected quadriplegics

• The patient's risk of hip dislocation is related to Gross Motor FunctionClassification System (GMFCS) level, with a 0% incidence for patients withgrade I function (near-normal motor activity) and 90% for patients withgrade V function (no head control, totally dependent)

• The natural history of the untreated hip in these patients is progressivesubluxation associated with bony deformity of the proximal femur andacetabulum

• The spastic adductors and hip flexors compress the femoral head againstthe posterolateral acetabulum and labrum

• The capsule and superior rim of the acetabulum cause focal deformation ofthe femoral head

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•The indented femoral head locks on the acetabular rim, causing significantcartilage loss and pain

•With continued abnormal muscle forces, the hip typically dislocatessuperolaterally, which has been confirmed by CT studies

•Late findings include dislocation of the hip and degenerative changes

•Most authors agree that hip subluxation and dislocation should be prevented inall patients who are medically able to tolerate treatment

•A patient with a long-standing dislocation is not a good candidate for arelocation procedure because of the deformities of the proximal femur andacetabulum

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Subluxation and Dislocation• Treatment options for hip dislocations in patients with cerebral palsy include

observation, relocation procedures on the femur, acetabulum, or both,proximal femoral resection, hip arthrodesis and in carefully selected patientstotal hip arthroplasty

• Regardless of the procedure performed, the greatest improvement in quality

of life and therefore the surgical goals should be pain relief and improved

motion of the hip

• Drummond et al. noted that a dislocated hip usually is not disabling in a

severely affected patient who is neurologically immature, extremely

intellectually impaired, bedridden, and institutionalized

• These authors established four criteria for open reduction of a dislocated

hip: (1) the patient must be moderately mature intellectually, (2) the patient

should have at least sitting potential if not walking ability, (3) pelvic obliquity

should be minimal or corrected, and (4) dislocation should ideally be

unilateral11

Varus Derotational Osteotomy• Varus derotational osteotomy, usually combined with soft tissue releases, is

indicated for patients with excessive anteversion and valgus deformity of theproximal femur and a hip that is either subluxated or dislocated

• Computer models have shown that to normalize the muscle forces across aspastic hip, the psoas, iliacus, gracilis, and adductor longus and brevis mustbe released

• The benefit of a varus derotational osteotomy comes primarily through thebony shortening that acts biomechanically similar to a soft tissuelengthening

• Decreasing the neck-shaft angle and anteversion has little effect on the hipforces

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Varus Derotational Osteotomy

• An isolated varus derotational osteotomy, often with femoral shortening, is

indicated only when there is little or no acetabular dysplasia present

because the remodeling potential of the acetabulum is poor in patients with

cerebral palsy

• Varus derotational osteotomy can be combined with an acetabular

osteotomy if significant subluxation and acetabular dysplasia are present

• The risk of recurrent dislocation is higher in patients with insufficientcorrection of valgus and acetabular dysplasia, and the risk of osteonecrosisis proportional to the patient’s age and degree of preoperative subluxation

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Combined One-Stage

Correction of Spastic

Dislocated Hip

(San Diego Procedure)

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Lateral Approach (Femoral Osteotomy)

•Lateral Approach (Femoral Osteotomy)

•Make an incision on the lateral aspect of the proximal femur, and perform alateral exposure

•Split the tensor fasciae latae, and dissect to the lateral aspect of the femur

•Perform a varus derotational shortening femoral osteotomy at the lessertrochanter and remove 1 to 2 cm of bone

•The neck-shaft angle should be decreased to 110 degrees, and anteversionshould be corrected to 10 to 20 degrees

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Lateral Approach (Femoral Osteotomy)

• Fix the femoral osteotomy with an AO blade plate of the appropriate size forthe child

• In most children younger than 10 years old, an infant plate can be used; apediatric hip screw and side plate also can be used

• When screw and side plate fixation is used, it is important to perform amedial displacement osteotomy of the distal fragment because mostpediatric systems do not have the offset found in angled blade plates usedin adults

• Without medial displacement of the distal fragment, screw and plate fixationcan result in tightening of the hip adductors, increasing one of the maindeforming forces of the hip

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A: Skin incision

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B: Incision through gluteus maximus and fascia lata (iliotibial tract)

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C: Greater trochanter, quadratus femoris, origin of vastus lateralis,

tendinous attachment of gluteus maximus, and linea aspera are

identified

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D: Osteotomy site is exposed in area of lesser trochanter; psoas

tendon can be released if necessary

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E: Guidewire and chisel are inserted in parallel position. Shaded area

represents wedge to be excised; scored line is for reference for later

rotation

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F: Location of osteotomy planes; proximal osteotomy is 15 mm distal to

chisel

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G: Rotation is accomplished by external rotation of femur

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H: Osteotomy is fixed with AO plate and screws

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Anterior Approach (Pericapsular Pelvic Osteotomy)

•Make an anterior bikini incision from the middle of the iliac crest to a point

midway between the anterior superior iliac spine and the midline of the pelvis

•The anterior superior iliac crest should be at the midpoint of the incision, which

can be placed 1 cm below the iliac crest

•Make the second incision parallel to the iliac crest using a Salter incision

•Place five nonabsorbable No. 1 sutures into the capsulotomy for later closure

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• With a straight osteotome, make an osteotomy 0.5 to 1.0 cm above theedge of the acetabulum, on a line drawn between the anterior inferior iliacspine and the sciatic notch

• Extend this through the lateral wall of the pelvis, but not through the medial

wall

• To allow proper bending, both corners should be cut at the anterior andposterior ends of the osteotomy (anterior superior iliac spine and sciaticnotch)

• This is most easily done by using a regular rongeur anteriorly and a largeKerrison rongeur posteriorly in the sciatic notch

• Use a curved osteotome 1.9 to 2.5 cm wide and an image intensifier toperform the second part of the osteotomy

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• Direct the osteotome halfway between the articular surface and the medialcortex

• Extend the cut medially and distally to the level of the triradiate cartilage

• Use gentle downward pressure on the osteotome to open the osteotomysite 1.0 to 1.5 cm

• Remove a bicortical graft from the iliac crest, and shape it into three or fourtriangular grafts measuring approximately 1 cm at the base

• Insert the grafts into the osteotomy, using the largest one for the area ofmost desired coverage

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Mubarak et al. one-stage correction of spastic dislocated hip

A, Pericapsular acetabuloplasty is begun approximately 1 cm above lateral margin of acetabulum

B, Osteotomy proceeds in line between anterior inferior iliac spine and sciatic notch, penetrating outer

wall of ilium only

Bicortical cuts are made at anterior inferior iliac spine and sciatic notch

Straight or slightly curved osteotome extends osteotomy toward triradiate cartilage, avoiding

penetration of joint or inner pelvic wall

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• Alternatively, tricortical allograft bone can be used, which gives goodstructural support to the osteotomy

• When a stable reduction is obtained, repair the capsule using the suturesplaced earlier

• Close all three wounds in standard fashion, and check a radiograph toensure proper reduction before application of a hip spica cast with the hip in45 degrees of flexion and 30 degrees of abduction

• The patient is placed in a well-padded spica cast, which typically is removed

at 6 weeks postoperatively with the patient anesthesized

• Physical therapy for range of motion and progressive weight bearing are

started after cast removal, but vigorous physical therapy and attempted

weight bearing are not advised until 10 weeks after surgery

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• Proximal femoral resection, combined with soft tissue interposition, as

described by Castle and Schneider has been effective in relieving pain

associated with a painful dislocated hip

• The advantage of this type of resection is that it is technically

straightforward, requires less postoperative immobilization and operating

room time, and requires no permanent implants, in contrast to other

techniques such as relocation procedures and arthrodesis

• Castle and Schneider reported improved sitting comfort, ease of care, and

skin condition in all 12 of their patients who had proximal femoral resection

• After administration of general anesthesia, place the patient supine with a

sandbag elevating the affected hip

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• Make a straight lateral incision along the proximal femur beginning 10 cm

superior to the greater trochanter and ending inferior to the level of the

lesser trochanter

• Split the fascia of the tensor fasciae latae and extraperiosteally detach the

insertions of the vastus lateralis and gluteus medius and minimus from the

proximal femur

• Detach the psoas tendon from the lesser trochanter, and complete the

exposure of the proximal femur extraperiosteally

• Incise the periosteum circumferentially around the femur just distal to theinsertion of the gluteus maximus or at the proposed level of femoralresection

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• Determine the level of the osteotomy by drawing a line on the preoperativeanteroposterior radiograph from the ischium to the femur, parallel to theinferior border of the ischium

• Divide the short external rotators

• Incise the capsule circumferentially, and free it from the base of the femoralneck

• Divide the ligamentum teres, and remove the proximal femur, using anoscillating saw to make the osteotomy

• Test the range of motion of the hip at this point, and, if necessary for motion,tenotomize the proximal hamstrings through the same incision afteridentifying the sciatic nerve

• If necessary, also release the adductors

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• Seal the acetabular cavity by oversewing the capsular edges. Alternatively,the iliopsoas can be sutured to the lateral part of the capsule and theabductors to the medial part of the capsule

• Bring the vastus lateralis lateral to medial over the femoral stump, sewing itinto the rectus femoris muscle

• Interpose the gluteal muscles between the acetabulum and the proximalfemur

• To decrease the risk of heterotopic ossification, handle tissue carefully,completely excise the periosteum, and irrigate thoroughly

• Secure meticulous hemostasis, and close the wound over a suction drain

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McCarthy et al. proximal femoral

resection

A, Extraperiosteal approach,

periosteal excision, and release of

musculotendinous attachments

B, Interpositional arthroplasty-

iliopsoas and abductors are sutured

to hip capsule, and femoral stump is

covered by vastus lateralis

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• Postoperative Care

• Skeletal traction is applied immediately after surgery and is removed dailyfor gentle exercises

• Gentle range-of-motion exercises emphasizing maximal flexion andextension, abduction, and internal and external rotation of the hip arestarted on the second day after surgery

• Over the first 6 weeks of traction, the head of the bed is gradually elevatedto prevent post traction hypotension

• Patients are allowed back into a wheelchair as tolerated

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• Hip arthrodesis also can be effective in relieving pain and improving functionin carefully selected patients. The ideal candidate is a patient with unilateraldisease and no spinal involvement

• Hip arthrodesis may be preferable in ambulatory patients because it allowsweight bearing, in contrast to proximal femoral resections

•Place the patient supine with a soft pad under the gluteal region and perform

an adductor tenotomy

•Through a longitudinal lateral incision to the hip, split the gluteal muscles

•Extend the exposure of the hip joint to allow an iliopsoas tenotomy

•Resect the pulvinar and ligamentum teres, remove any remaining cartilage

from the femoral head and acetabulum, and deepen the dysplastic acetabulum

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• Position the hip in 40 degrees of flexion, 15 degrees of abduction, andneutral rotation

• The fixation device used depends on the local bone width and quality, thesize of the femoral head and neck, and the desirable degree of hip flexion

• Appropriate implants include a 4.5-mm AO-D cerebral palsy plate, AO-Cobra plate, and 6.5-mm cannulated screws

• Postoperative Care

• A hip spica cast is worn for 2 months postoperatively

• Patients are then started in a progressive range-of-motion and weight-bearing program

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Total Hip Arthroplasty

•Total hip arthroplasty is an option for patients with cerebral palsy with end-stage hip degeneration

•The ideal candidate is an intelligent, independent ambulator with mild softtissue contractures

•Good long-term results (<10 years) have been reported after hip arthroplasty

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THANK YOU

the hip in cerebral palsy part 2 of 2

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