Hip and Spine Surgery is of Questionable Value in Spina Bifida: An Evidence-based Review

Abstract

Background

Although many children with spina bifida and associated scoliosis or dislocated hips undergo spine or hip surgery, the benefits are uncertain.

Questions/purposes

The purpose was to perform an evidence-based review on the benefits and risks of surgery for dislocated hips and scoliosis in spina bifida.

Methods

I performed a Medline^® and Embase^® search from 1950 to 2009 for Level I to Level III studies investigating the benefits and risks of surgery for scoliosis and hip dislocation in patients with spina bifida. When available, I extracted types of surgery, complication rates, functional outcomes of seating, walking, and overall physical function. All treatment recommendations received a Grade of Recommendation: Grade A (consistent Level I studies); Grade B (consistent Level II and III studies); Grade C (consistent level IV and V studies); or Grade I (insufficient or contradictory studies).

Results

Combined anterior and posterior surgery had lower rates of nonunion for scoliosis. Although there may be some benefit in seating, overall physical function measured in a different and nonstandardized fashion was not much changed and major complication rates, including nonunion and infections for scoliosis surgery, exceed 50% in several studies. For dislocated hips, the impact on walking ability appears related to contracture (not dislocation). Surgery for hip dislocation did not improve walking ability. The literature provides no guidance on the best treatment for unilateral dislocation.

Conclusions

The benefits of scoliosis surgery are uncertain (Grade I). Spine surgery, if performed, should be anterior and posterior (Grade B). An all-pedicle approach for scoliosis surgery may be effective (Level I). Hip reduction surgery did not improve walking (Grade B) but may be appropriate in low-level unilateral dislocation (Level I).

Appendix 1. Summary of key articles

Hip Dislocation

Bazih and Gross [7] evaluated 74 patients with myelomeningocele older than 4 years including all neurosegmental levels. Of the 74 patients, 18 had had surgery. The subluxation and redislocation rate after surgery was 45%. The level of neurosegmental defect, not hip dislocation, was the most important factor in determining ambulation. The key comparison, in lower lumbar patients, found 10 of 13 who had surgery compared with 14 of 14 patients who had not had surgery were household ambulators or better. The authors concluded there was no overall beneficial effect of surgery on ambulation.

Crandall et al. [11] reviewed 100 patients with dislocation or hip dysplasia older than 10 years. Ambulatory function at each neurosegmental level was not affected by whether the hips were located or dislocated. In the lower-level patients, two of eight nonambulators compared with five of 15 ambulators had hip dislocations. The authors concluded the functional level was related to the neurosegmental level and not whether the hips were located.

Feiwell et al. [14] studied 76 patients with spina bifida of all neurosegmental levels older than 5 years. Of the 76 patients, 41 had no operative treatment for the hip and 35 had been operated on one or more time to reduce the hip. The redislocation rate after surgery was 40%. Using multivariable analyses, the presence of a reduced hip was not related to ambulatory ability. The key comparison for patients with lower lumbar level found, of 16 ambulators, five (30%) had dislocated hips, whereas of the five patients who were nonambulators, one (20%) had a dislocated hip. The authors concluded hip dislocation was not related to ambulation.

Sherk and Ames [25] examined 36 children who had open reduction and iliopsoas transfer with other hip procedures for lumbar L1 to L5 level patients. Of the 36 children, 19 patients had a redislocation of one or both hips. The authors concluded the presence of located hips was unrelated to walking ability.

Alman et al. [3] reviewed 52 children with dislocated hips with L3 or L4 level lesions. Of the 52 patients, 30 patients had a variety of surgical procedures. The overall redislocation rate after surgery was 30%. The ambulatory level and functional ability scores (using Child Health Assessment Questionnaire and Rand Health Insurance Functional Score) of patients with and without surgery was similar. Restriction in motion and limb length discrepancy was greater in the surgical group. A small subgroup of 12 patients who had surgery had a slightly increased efficiency of gait. The authors concluded the benefits of surgery for surgical dislocation were at best marginal.

In addition to the therapeutic papers examining the benefits of hip surgeries, 10 Level II prognostic studies examined factors related to ambulatory ability in patients with spina bifida. The reported factors related to walking included cognitive ability [10], physiotherapy [10], compliant parents [10], neurosegmental level [6, 12, 15, 30], club foot deformity [12], hip and knee contractures [2, 6, 23], low back pain [6], lack of motivation [6], age [2, 23, 30], and scoliosis [23]. None of the studies reported a relationship between hip location and walking ability.

Scoliosis

Unfortunately, none of the identified studies directly compared the function of patients with spina bifida and scoliosis with and without surgery. Only two cross-sectional studies examined the relationship between function and the presence of scoliosis. Kahanovitz and Duncan [17] evaluated 39 patients with spina bifida and scoliosis with an average of 19.9 years’ followup. Of the 39 patients, 15 had had surgery. Of these 15 patients, eight maintained, seven lost, and none improved their functional level. Although the presence of scoliosis and pelvic obliquity were related to poor seating, the authors concluded the benefits surgery were uncertain. Wai et al. [28] performed a cross-sectional study of 98 children with spina bifida and scoliosis. Using multivariable analyses, all aspects of spinal deformity were evaluated for their relationship with sitting balance, Jebsen Hand scale, Hoffer ambulation scale, Spina bifida Spine Questionnaire, Harter’s Self Perception Scale, and the Activities Scale for Kids. Of all aspects of spinal deformity, only one, spinal balance, had any clinically significant relationship with only one aspect of function, seating. The authors concluded, in the short term, the potential benefits of surgery may be at best to improve only seating balance. Thus, the two studies that evaluated the relationship between surgery and function found no or minimal benefit.

The remainder of the studies focused on comparisons of different surgical techniques. Mazur et al. [18] evaluated 49 patients with spina bifida and scoliosis comparing anterior and posterior surgery with posterior and anterior surgery alone. Although sitting was improved in 70% of patients, the ability to ambulate was adversely affected in 67% of patients who had received anterior and posterior surgery. Although correction of deformity and pelvic obliquity were similar among the three methods, the rate of nonunion was 11% in the combined anterior and posterior group compared with 33% and 29% in the posterior and anterior fusion alone groups, respectively. The conclusion was that a combined anterior and posterior approach was most appropriate for children with spina bifida.

Parisini et al. [21] compared Harrington, Harrington-Luque, and all-pedicle screws posterior-only approaches with a two-stage anterior and posterior spinal fusion in 33 patients with spina bifida. The correction of deformity was greater in both the combined anterior and posterior fusion group and the all-pedicle posterior-only approach. The authors concluded the combined anterior and posterior procedure and all-pedicle single posterior approach using pedicle screws provided satisfactory correction.

Stella et al. [27] reviewed, at an average of 8 years’ followup, the surgical treatment of 14 patients with scoliosis and spina bifida. Although the numbers are small, the conclusion of the authors was that combined anterior and posterior surgery with fusion to the sacrum provided the best results.

Stella et al. [27] evaluated 29 patients with spina bifida who were treated using spinal fusion techniques, seven by posterior arthrodesis, three by anterior arthrodesis, and 19 by the combined anterior and posterior approach. The correction of deformity was highest in the combined anterior and posterior instrumentation and fusion group with 14% nonunion. The authors concluded combined anterior and posterior instrumentation fusion gave the best results.

Ward et al. [29] compared anterior and posterior fusion with anterior or posterior procedures alone. Although a variety of techniques were used, better curve correction and lower nonunion rates were obtained with a combined anterior and posterior approach. The authors reported no advantage to adding anterior instrumentation to the anterior approach and no superiority of Luque or Harrington posterior instrumentation.

Banit et al. [4] reviewed 50 patients with at least 1-year followup of which six received Harrington rods and 47 received segmental fixation. The authors concluded the combined anterior and posterior surgery with segmental fixation had the lowest nonunion rate of 16%.

Osebold et al. [20] reported 40 patients who had spina bifida and scoliosis. The author reported combined anterior and posterior surgery had better correction of deformity and a nonunion rate of 23% compared with a rate of 46% in the posterior fusion-only group.

Only two studies, both case series (Level IV), addressed the issue of pulmonary function after spine fusion for patients with spina bifida and scoliosis. Banta and Park [5] evaluated 10 patients on average 10 months after staged anterior Dwyer and posterior Harrington instrumentation. Although peak flow increased in eight, forced vital capacity and forced expiratory volume in 1 second (FEV1) decreased in five patients. Carstens et al. [9] evaluated 10 patients 13 months after anterior and posterior instrumentation with fusion. The results were mixed, but eight had an increase in vital capacity and six had an increase in FEV1.

Although only a case series (Level IV), Schoenmakers et al. [24] performed the only study to examine the functional abilities before and after spinal fusion. Ten children with spina bifida were followed prospectively and evaluated with the Pediatric Evaluation of Disability Inventory on average 18 months after surgery. Although all patients had improvement in their spinal deformity, of four patients who had been able to ambulate before surgery, three had difficulty after surgery. Patients also experienced a postsurgical decline lasting for at least 6 months. By 18 months after the surgery, there had been a slight improvement in functional skills, specifically self-care, indicating less caregiver assistance. However, the overall complication rate was 80%.