Abduction pillow immobilization following hip surgery: A welcome alternative for selected patients

Introduction

Children with neuromuscular disorders and other genetic syndromes undergo hip surgery for many reasons, such as hip subluxation, dislocation, and acetabular dysplasia. Femoral and/or pelvic osteotomies, often in conjunction with open hip reduction, followed by spica cast immobilization are the main method for accomplishing this surgically in the immature patient [1–4].

Osteopenic disuse fractures possibly related to the spica cast following surgery have been reported in up to 6 of 21 (29%) non-ambulatory cerebral palsy (CP) patients [5]—Mubarak et al. [1] reported their occurrence in 1 of 11 CP patients (9%), Pritchett [6] in 9 of 50 CP patients (18%), and Stasikelis et al. [7] in 16 of 79 CP patients (20%). Miller et al. [8] described there being no fractures in 51 patients with dysplastic spastic hips after surgery, followed 2–3 days later by physical therapy with no form of immobilization. Decubiti ulcers have been reported in 7 of 76 (9%) patients by Stasikelis et al. [7] and 0 of 14 (0%) by Sankar et al. [9]

In order to decrease the risks associated with spica casts, all patients with no diagnosis of developmental dysplasia of the hip (DDH) were placed in an abduction brace post-operatively. We present our experience using abduction pillows post-operatively following hip surgery.

Materials and methods

All patients with who had undergone hip surgery requiring post-operative stabilization between 1999 and 2005 by one surgeon at our institution were identified retrospectively. A total of 33 patients were identified who were treated with either an abduction pillow and knee immobilizer or a spica cast. Of these 33, 1 had no adverse outcomes, but we were unable to obtain at least 5 months of follow-up records. Since other studies demonstrate that most peri-operative events occurred within 3–5 months of the surgery [7], only charts with at least 5 months follow-up were included in the study. Of the remaining 32 patients, 21 underwent hip surgery and were treated with an abduction pillow and 11 were treated post-operatively with a spica cast. All records were searched for adverse outcomes, including decubiti ulcers, fractures, death, or dislocations.

Of the 21 patients who were treated using an abduction pillow and a knee immobilizer on the operated leg, there were 32 hips that had a femoral and/or pelvic osteotomy (Table 1). The average age at treatment was 7.9 years (5.8–20.8 years) and average follow-up was 34.7 months (3–96 months). Of these 21, 16 patients had CP and 5 had genetic syndromes. A total of 2 patients underwent two-stage reconstructions with one hip being operated on 2–3 weeks before the other hip, with an abduction pillow used in the interim.

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Table 1

Patients treated with spica cast. VDRO varus derotational osteotomy, CP cerebral palsy

Patient no.	Age (years)	Sex	Months of follow-up	Underlying diagnosis	Previous hip surgeries	Ambulatory status	Surgical diagnosis	Surgical site	Femoral osteotomy	Pelvic osteotomy	Soft tissue release	Second stage surgery
1	5.8	Male	22	CP	None	Non-ambulatory	Bilateral hip dislocation	Bilateral	VDRO		Yes	No
2	8.3	Male	6	Pallister-Hall syndrome	None	Independent	Bilateral hip subluxation	Left	VDRO	DEGA	No	No
3	3.9	Female	51	CP	None	Non-ambulatory	Right hip dislocation	Right	VDRO		Yes	No
4	12.3	Female	7	CP	None	Independent	Right hip dislocation	Right	VDRO	Chiari	Yes	No
5	4.7	Male	45	Spina Bifida	Previous B osteotomy in 2000	Non-ambulatory	Bilateral hip dislocation	Bilateral	VDRO		No	No
6	6.9	Female	8	CP	None	Non-ambulatory	Left hip subluxation	Left	VDRO		Yes	No
7	7.3	Male	32	McCune Albright/polycystic fibrodysplasia	IM Rod for Femur Fx	Independent	Deformity of bilateral femurs	Bilateral	Osteotomy with placement of flexible rods		No	No
8	8.6	Female	62	Kniest	None	Independent	Bilateral coxa vara	Bilateral	Valgus		No	No
9	2.3	Female	16	CP	None	Independent	Right hip dislocation	Right	VDRO		Yes	No
10	7.2	Female	29	CP	None	Non-ambulatory	Bilateral hip dysplasia with right dislocation	Bilateral	VDRO	Salter	No	No
11	9.6	Male	45	CP	None	Non-ambulatory	Right hip subluxation	Right	VDRO		No	No
12	7.8	Female	6	Unknown skeletal dysplasia	None	Independent	Bilateral coxa vara	Bilateral	Valgus		No	No
13	8.3	Male	60	Legg-Perthes	None	Independent	Left legg-perthes disease	Left	VDRO		No	No
14	16.0	Female	10	CP	None	Independent	Left hip dislocation	Left	VDRO	Chiari	No	No
15	13.8	Male	5	Morquio's syndrome	None	Independent	Bilateral hip subluxation	Right	VDRO		No	No
16	4.3	Female	74	CP	None	Non-ambulatory	Bilateral hip subluxation	Bilateral	VDRO		No	No
17	9.0	Male	8	CP	None	Non-ambulatory	Right hip dislocation	Right	VDRO	Chiari	No	No
18	8.0	Male	43	CP	None	Non-ambulatory	Bilateral hip subluxation	Bilateral	VDRO		No	No
19	5.2	Female	27	CP	None	Non-ambulatory	Right hip dislocation	Right	VDRO	DEGA	No	No

Of the 11 patients treated using a spica cast, every one had a diagnosis of DDH and was operated on with a pelvic and/or femoral osteotomy. The average age of the patients was 2.3 years old (0.3–4.8 years) at the time of surgery. The average follow-up time was 32.5 months (8–84 months) (Tables 2, 3).

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Table 2

Patients treated using abduction pillow. VDRO varus derotational osteotomy, CP cerebral palsy

Patient no.	Age at surgery (years)	Sex	Months of follow-up	Underlying diagnosis	Previous hip surgeries	Ambulatory status	Surgical diagnosis	Surgical site	Femoral osteotomy	Pelvic osteotomy	Soft tissue release	Second stage surgery
19	5.8	Female	33	CP	None	Non-ambulatory	Left hip dislocation	Left	VDRO	DEGA	No	No
20	7.3	Female	61	Mitochondrial d/o	None	Independent	Bilateral hip subluxation	Left	VDRO	DEGA	No	R VDRO and R DEGA
21	8.9	Male	84	CP	None	Independent	Left hip dislocation	Left	VDRO	DEGA	Yes	No
22	20.8	Female	18	Hodgkins and treated with steroids	Multiple previous hip surgeries	Independent	Left AVN and femoral neck fracture	Left	Valgus		No	No
23	7.8	Male	17	CP	None	Non-ambulatory	Bilateral hip subluxation	Bilateral	VDRO		Yes	No
24	16.2	Male	40	CP	None	Non-ambulatory	Adducted left hip	Left	Valgus		Yes	No
25	9.5	Male	12	CP	None	Non-ambulatory	Right hip dislocation	Right	VDRO		Yes	No
26	6.2	Male	55	CP	None	Non-ambulatory	Right hip subluxation	Right	VDRO	DEGA	No	L VDRO and L Dega
27	6.9	Male	96	CP	None	Non-ambulatory	Left hip dislocation	Left	VDRO		Yes	No
28	12.0	Female	7	CP	Adductor release	Non-ambulatory	Left hip dislocation	Left		Shanz	No	No
29	5.4	Male	38	B fibrous dysplasia	None	Independent	Fibrous dysplasia deformity	Bilateral	Curettage of bone tumor of proximal femur head		No	No
30	6.9	Female	12	CP	None	Independent	Gait study	Bilateral	VDRO		Yes	No
31	6.8	Female	14	Unknown skeletal dysplasia	None	Independent	Bilateral coccyvera	Bilateral	Valgus		No	No
32	5.5	Female	32	CP	None	Non-ambulatory	Left hip dislocation, windwept hips	Bilateral	VDRO	Pelvic osteotomy on left side only	Yes	No
33	8.3	Female	27	CP	Adductor release	Non-ambulatory	Left hip dislocation, windwept hips	Bilateral	VDRO		No	No
34	4.3	Male	69	CP	None	Non-ambulatory	Right hip subluxation	Right	VDRO		Yes	No
35	4.7	Female	10	Kubaki	None	Independent	Bilateral hip subluxation	Bilateral		DEGA	No	No
36	2.8	Male	11	CP	None	Independent	Bilateral hip subluxation	Bilateral	VDRO		Yes	No
37	5.0	Male	5	CP	None	Non-ambulatory	Right hip dislocation, Left hip subluxation	Bilateral	VDRO		No	No
38	9.8	Male	5	CP	Hamstring release	Crutches	Bilateral hip subluxation	Bilateral	VDRO		Yes	No
39	4.2	Female	84	CP	None	Non-ambulatory	Bilateral hip subluxation	Bilateral	VDRO		Yes	No

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Table 3

Adverse peri-operative outcomes

Patient no.	Stabilization	Adverse outcome	Time post-operative	Resolution
1	Spica cast	Decubiti ulcer and urine staining on the cast	12 days	Spica cast was padded and trimmed. Decubiti ulcer resolved with normal wound care
4	Spica cast	Decubiti ulcer and fecal staining on the cast	9 days	Spica cast was padded and trimmed. Decubiti ulcer resolved with normal wound care
9	Spica cast	Decubiti ulcer and fecal staining on the cast	6 weeks	The cast was removed and ulcer resolved with wound care
18	Spica cast	Decubiti ulcer	10 days	Spica cast was padded and trimmed. Decubiti ulcer resolved with normal wound care
27	Abduction brace	Left femur fracture	10 weeks	Patient placed in long leg cast and healed without incident
37	Abduction brace and spica cast	Potential hardware fixation failure	12 days	Patient switched to a spica cast with no change in X-ray
39	Abduction brace and spica cast	Superiorly migrating right hip	8 days	Patient reduced and changed to spica cast. In the spica cast there was proximal migration of the femoral head.

Results

Of the 21 patients who were treated using an abduction pillow (Fig. 1) after surgery, 17 experienced no complications during the peri-operative period. Patient 20 was a 9.8-year-old male with CP who switched from the abduction pillow to a spica cast 8 days after a varus derotational osteotomy (VDRO), because the mother stated that the knee immobilizers were sliding down the patient's legs and were difficult to maintain. The hips were well located on X-ray before and after changing to a spica cast.

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Fig. 1

Abduction Pillow

One patient with quadriplegic CP sustained a distal femoral fracture 10 weeks after the surgery. This patient was 6.9 years old at the time of the surgery and non-ambulatory; 10 weeks after surgery, while being stabilized with an abduction pillow, the patient was noted by his mother to be choking on a hotdog. During forceful manipulation to dislodge the hotdog, the patient sustained a left distal femoral fracture. The patient was converted to a spica cast and the hip surgery and femur fracture healed without incident.

Another patient, a 5-year-old male with CP was immobilized using an abduction pillow following VDRO. A potential loss of implant fixation was noted on X-ray at his 2-week follow-up appointment. The patient was changed to a spica cast, and on repeat X-ray there was no radiographic change in implant position. The spica cast was removed 6 weeks post-operatively and the implant remained in place with the VDRO well healed.

One week after performing bilateral VDRO on a 4-year-old non-ambulatory patient with CP, it was noted on radiographs that the right hip was superiorly migrating. The next day, the patient underwent general anesthesia, the hip was reduced in a closed manner, and a spica cast was placed. And 2 days later, X-rays showed that the femoral head was again migrating superiorly. A Dega pelvic osteotomy was performed after a further 3 days, and the patient was placed in a spica cast after the surgery. The hip then remained reduced.

In the 11 patients treated with a spica cast, 10 experienced no adverse events. Patient number 25 had a wound infection 2 weeks post-operatively with an elevated CRP of 3.0. The patient was administered IV antibiotics and the infection resolved. Her femoral head was noted to be migrating laterally on X-ray 3 months post-operatively, and a repeat pelvic osteotomy with spica stabilization was thus performed. The hip then remained reduced with no further complications.

Discussion

Many children with CP and other genetic conditions require hip surgery for subluxated and/or dislocated hips. Due to their many co-morbidities, complications following such surgery are common. There have been many recognized complications associated specifically with spica casts, such as osteopenic disuse fractures and, rarely, vessel [10] or nerve [11] damage along with perineal care issues that the cast presents. Decubiti ulcers related to the spica cast have been reported in 0–9% of patients with CP following hip surgery and spica cast application [7, 9].

Osteopenic disuse fractures, mostly distal femur/proximal tibia, are associated with application of a spica cast following surgery. Sturm et al. [5] observed fractures in 6 of 21 non-ambulatory CP patients who had been operated on for subluxed or dislocated hips and treated with a spica cast. Shea et al. [12] reported no fractures in 15 patients with CP who underwent a Pemberton pericapsular osteotomy to treat a dysplastic hip. In a study by Mubarak et al. [1], 1 of 11 patients sustained a fracture after pericapsular acetabuloplasty and spica stabilization, and Root et al. [13] observed femoral fractures in 3 of 31 patients with CP who had an open reduction, pelvic osteotomy, and femoral osteotomy with shortening with stabilization using a spica cast. Of 47 patients with spastic CP, Brunner et al. [3] observed 2 to sustain a femoral fracture within 3 months of surgical reconstruction of a dislocated or subluxated hip stabilized using a spica cast.

Miller et al. [2] has advocated a routine of physical therapy starting 2 days after pre-ilial pelvic and femoral osteotomy surgery. Of his 51 patients treated in this manner, 1 was placed in a spica cast due to instability of the hip and had a fracture immediately after the cast was discontinued, and 1 had a fracture while getting out of bed 4 weeks after surgery. At a mean follow-up of 34 months, two hips in 2 patients had redislocated, requiring repeated surgery. Two hips remained subluxated and asymptomatic.

To the best of our knowledge, there has been no study examining the use of an abduction pillow after surgery about the hip. This study presents our experience with selective use of an abduction brace in all patients requiring hip stabilization post-operatively; excluding patients with DDH, who were treated in spica casts in order to have greater stabilization.

In our experience, we had 2 patients who had an adverse complication that occurred only while in the abduction pillow. One patient sustained a distal femoral fracture 10 weeks after surgery while his mother was vigorously beating on his back trying to stop him from choking. There is a good likelihood that this fracture would have occurred with or without the recent surgery and abduction pillow. Another child had partial loss of fixation of the hardware in the abduction pillow. This is the one child who very well may have done better if he had been placed in a spica cast immediately; however, the VDRO went on to heal uneventfully in acceptable position.

An additional patient had superiorly migrating hip in the abduction pillow, which was then treated with closed reduction and spica cast application. The hip again migrated superiorly in the spica cast and went on to have a pelvic osteotomy. This complication was most likely a failure of the surgery itself, in that a pelvic osteotomy at the time of the index surgery may have prevented hip migration post-operatively, regardless of post-operative immobilization.

This paper has limitations. Inherent to a retrospective study, the patients were not randomized. The numbers of patients are modest, and it is possible that larger numbers would show different results. The study does not look at the use of an abduction brace for developmental dysplastic hips in otherwise normal children, so these findings are not necessarily applicable to that population. Our findings suggest that the use of an abduction pillow and knee immobilizer or a spica cast following hip surgery in children with neuromuscular and syndromic conditions is generally effective and safe. Selected patients, such as those with poor bone quality in whom implant failure is a risk or those cases of an unstable hip reduction, may do better if treated using a spica cast. Overall, parents and medical staff were much happier caring for children in an abduction pillow and knee immobilizer for many reasons, including perineal care and ease of movement because of the weight of the cast.