FUNCTIONAL AND RADIOGRAPHIC OUTCOMES OF ADDUCTOR

MYOTOMY IN PATIENTS WITH SPASTIC CEREBRAL PALSY Marquez-Lara A, MD 1 Swaroop VT, MD2,3 Dias LS, MD2,3 1Wake Forest School of Medicine, Winston-Salem, NC; 2 Rehabilitation Institute of Chicago, Chicago, IL; 3 Northwestern University Feinberg School of Medicine, Chicago, IL

OBJECTIVES •Hip displacement is the 2nd most common musculoskeletal deformity in children

with spastic cerebral palsy (SCP)

•In children with SCP, adductor myotomy (AM) can delay or prevent worsening

hip subluxation

·May obviate further surgical procedures

•Debate remains over the success of this preventive intervention

•Purpose of this study:

1. Analyze functional and radiographic outcomes of AM performed for hip

subluxation

2. Assess risk factors associated with subsequent surgical interventions

METHODS •134 consecutive patients who underwent AM by single surgeon btw 1977-2007

•Charts reviewed for demographics, GMFCS, hip range of motion (ROM),

Reimer Index (RI) (Fig 1), and surgical details (Table 1)

•Included: Hip subluxation (RI ≥30°) or “Hip at risk” (RI <30°, hip abd <45°)

•Excluded: <5y postoperative follow-up, <12y old at final follow-up,

concomitant bony procedure at index surgery

•Surgical treatment: Goal = intraoperative abduction to 60°

·All patients underwent adductor longus myotomy; + brevis/gracilis as needed

·95% underwent concomitant soft tissue procedures

•Post-operative: Hip splint (Fig 2) or spica cast with hip abduction 40° x 3 weeks

·After 3 weeks, abduction wedge used at nighttime

·Individualized PT program for at least 6 weeks

•Subgroup analysis comparing GMFCS I-III vs IV-V

•Multivariate regression (95% confidence interval) performed to assess risks

associated with subsequent AM or bony surgery

•Independent t-test for continuous and χ2-test for categorical variables (p≤0.05)

* 25 patients did not have a reported GMFCS level

RESULTS •At average follow-up of 8.6 years after index procedure:

·82 (61%) did not require further surgical intervention

·17 (13%) required repeat AM

·12 (9%) required bony procedure

·23 (17%) required repeat AM + bony procedure

74% successfully treated without need for bony surgery

•Based on GMFCS level (Table 2):

·75% of GMFCS I-III patients

·56% of GMFCS IV-V patients

•Need for revision AM significantly different: (p<0.05)

·15% GMFCS I-III

·38% GMFCS IV-V

•No difference in need for subsequent bony surgery: (p=0.28)

·19% GMFCS I-III

·28% GMFCS IV-V

•Average RI at final follow-up was ≤30° in both groups

•GMFCS did not significantly impact risk of osteotomy (Table 3)

•2 and 3 AM were associated with ↑ risk of osteotomy:

·13% with 1AM, 53% with 2AM, 83% with 3AM

Successfully treated with single AM

(p<0.05)

DISCUSSION •Non-operative treatment (PT, bracing, Botulinum toxin) demonstrated only brief

clinical benefits without preventing progressive hip displacement (Graham et al 2008)

•Early detection of hip displacement and prompt surgical treatment ↓ late hip

dislocation, chronic hip pain, and need for subsequent salvage surgery (Dobson et al

2002, Hagglund et al 2005, Gordon et al 2006)

•However there is no consensus regarding treatment to manage hip subluxation

•Studies have demonstrated AM prevents progression of hip displacement (Moreau et

al 1995), but other authors have reported up to 58-77% patients who undergo AM for

hip subluxation require reoperation (Schmale et al 2006, Turker et al 2000)

•In our cohort of patients with hip subluxation undergoing AM:

·74% successfully treated without need for bony surgery

·30% required ≥ 2 AM

·26% required osteotomy

•Regression analysis: preop RI not associated with ↑ risk for subsequent bony surgery

•However, patients who require ≥2 AM, regardless of their functional status and

preoperative RI, may be at ↑ risk for subsequent bony intervention, and may be

important to consider when discussing patient expectations.

CONCLUSIONS •AM continues to have important role in treatment of hip displacement in SCP

·61% successfully treated with single AM

•Need for repeat surgery higher in patients with higher GMFCS

•Need for bony surgery did not vary based on GMFCS

•Patients requiring > 1 AM at ↑ risk for bony surgery

•This data can be utilized to help counsel patients and their families on risk of

further surgery based on functional level