Aims

Abduction bracing is commonly used to treat developmental dysplasia of the hip (DDH) following closed reduction and spica casting, with little evidence to support or refute this practice. The purpose of this study was to determine the efficacy of abduction bracing after closed reduction in improving acetabular index (AI) and reducing secondary surgery for residual hip dysplasia.

Aims

Perthes’ disease (PD) often results in femoral head deformity and leg length discrepancy (LLD). Our objective was to analyze femoral morphology in PD patients at skeletal maturity to assess where the LLD originates, and evaluate the effect of contralateral epiphysiodesis for length equalization on proximal and subtrochanteric femoral lengths.

We investigated the incidence and risk factors for the development of avascular necrosis (AVN) of the femoral head in the course of treatment of children with cerebral palsy (CP) and dislocation of the hip. All underwent open reduction, proximal femoral and Dega pelvic osteotomy. The inclusion criteria were: a predominantly spastic form of CP, dislocation of the hip (migration percentage, MP > 80%), Gross Motor Function Classification System, (GMFCS) grade IV to V, a primary surgical procedure and follow-up of > one year.

There were 81 consecutive children (40 girls and 41 boys) in the study. Their mean age was nine years (3.5 to 13.8) and mean follow-up was 5.5 years (1.6 to 15.1). Radiological evaluation included measurement of the MP, the acetabular index (AI), the epiphyseal shaft angle (ESA) and the pelvic femoral angle (PFA). The presence and grade of AVN were assessed radiologically according to the Kruczynski classification.

Signs of AVN (grades I to V) were seen in 79 hips (68.7%). A total of 23 hips (18%) were classified between grades III and V.

Although open reduction of the hip combined with femoral and Dega osteotomy is an effective form of treatment for children with CP and dislocation of the hip, there were signs of avascular necrosis in about two-thirds of the children. There was a strong correlation between post-operative pain and the severity of the grade of AVN.

Cite this article: Bone Joint J 2015;97-B:270–6.

Proximal femoral varus osteotomy improves the biomechanics of the hip and can stimulate normal acetabular development in a dysplastic hip. Medial closing wedge osteotomy remains the most popular technique, but is associated with shortening of the ipsilateral femur.

We produced a trigonometric formula which may be used pre-operatively to predict the resultant leg length discrepancy (LLD). We retrospectively examined the influence of the choice of angle in a closing wedge femoral osteotomy on LLD in 120 patients (135 osteotomies, 53% male, mean age six years, (3 to 21), 96% caucasian) over a 15-year period (1998 to 2013). A total of 16 of these patients were excluded due to under or over varus correction. The patients were divided into three age groups: paediatric (< 10 years), adolescent (10 to 16 years) and adult (> 16 years). When using the same saw blades as in this series, the results indicated that for each 10° of angle of resection the resultant LLD equates approximately to multiples of 4 mm, 8 mm and 12 mm in the three age groups, respectively.

Statistical testing of the 59 patients who had a complete set of pre- and post-operative standing long leg radiographs, revealed a Pearson’s correlation coefficient for predicted versus radiologically observed shortening when using a wedge of either 10° or 20° of 0.93 (p <  0.001). The 95% limits of agreement from the Bland–Altman analysis for this subgroup were –3.5 mm to +3.3 mm. It has been accepted that a 10 mm discrepancy is clinically acceptable.

This study identified a geometric model that provided satisfactory accuracy when using specific saw blades of known thicknesses for this formula to be used in clinical practice.

Cite this article: Bone Joint J 2014;96-B:1124–9

We reviewed the long-term radiological outcome, complications and revision operations in 19 children with quadriplegic cerebral palsy and hip dysplasia who underwent combined peri-iliac osteotomy and femoral varus derotation osteotomy. They had a mean age of 7.5 years (1.6 to 10.9) and comprised 22 hip dislocations and subluxations. We also studied the outcome for the contralateral hip. At a mean follow-up of 11.7 years (10 to 15.1) the Melbourne cerebral palsy (CP) hip classification was grade 2 in 16 hips, grade 3 in five, and grade 5 in one. There were five complications seen in four hips (21%, four patients), including one dislocation, one subluxation, one coxa vara with adduction deformity, one subtrochanteric fracture and one infection. A recurrent soft-tissue contracture occurred in five hips and ten required revision surgery.

In pre-adolescent children with quadriplegic cerebral palsy good long-term outcomes can be achieved after reconstruction of the hip; regular follow-up is required.

Cite this article: Bone Joint J 2013;95-B:259–65.

We undertook a retrospective analysis of 306 procedures on 233 patients, with a mean age of 12 years (1 to 21), in order to evaluate the use of somatosensory evoked potential (SSEP) monitoring for the early detection of nerve compromise during external fixation procedures for limb lengthening and correction of deformity. Significant SSEP changes were identified during 58 procedures (19%). In 32 instances (10.5%) the changes were transient, and resolved once the surgical cause had been removed. The remaining 26 (8.5%) were analysed in two groups, depending on whether or not corrective action had been performed in response to critical changes in the SSEP recordings. In 16 cases in which no corrective action was taken, 13 (81.2%, 4.2% overall) developed a post-operative neurological deficit, six of which were permanent and seven temporary, persisting for five to 18 months. In the ten procedures in which corrective action was taken, four patients (40%, 1.3% overall) had a temporary (one to eight months) post-operative neuropathy and six had no deficit.

After appropriate intervention in response to SSEP changes, the incidence and severity of neurological deficits were significantly reduced, with no cases of permanent neuropathy. SSEP monitoring showed 100% sensitivity and 91% specificity for the detection of nerve injury during external fixation. It is an excellent diagnostic technique for identifying nerve lesions when they are still highly reversible.

The Salter innominate osteotomy has been used successfully for many years in the treatment of developmental dysplasia of the hip. One of its main drawbacks is the need for internal fixation with pins and their subsequent removal. We describe a modification of this osteotomy that does not require pin fixation and secondary removal. We retrospectively reviewed 114 hips in 94 patients who had been operated on by a single surgeon. An oblique rather than the original horizontal osteotomy was used without internal fixation. There were 80 female and 14 male patients. The mean age at operation was 25 months (18 to 84) and the mean follow-up was 30 months (12 to 88). Most patients required additional open reduction and capsuloplasty. The mean pre-operative acetabular index was 37.9° (24° to 54°), which decreased to 19.9° (7° to 29°) in the immediate post-operative period, and improved to 14.6° (5° to 25°) at the final follow-up (student’s t-test, p < 0.0001).

We believe that by changing the direction of the osteotomy line, it is possible to avoid pin fixation. The radiological outcomes are comparable to those of the original technique, but longer follow-up will be necessary.

The results of a functional, clinical and radiological study of 30 children (60 hips) with whole-body cerebral palsy were reviewed at a mean follow-up of 10.2 years (9.5 to 11). Correction of windsweep deformity of the hips was performed by bilateral simultaneous combined soft-tissue and bony surgery at a mean age of 7.7 years (3.1 to 12.2).

We were able to recall 22 patients; five had died of unrelated causes and three were lost to follow-up. Evaluation involved interviews with patients/carers and clinical and radiological examination.

The gross motor functional classification system was used to assess overall motor function and showed improvement in seven patients. Of the 12 patients thought to have pain pre-operatively, only one had pain post-operatively. Improved handling was reported in 18 of 22 patients (82%). Those with handling problems were attributed by the carers to growth of the patients. All patients/carers considered the procedure worthwhile. The range of hip movements improved, and the mean windsweep index improved from 50 pre-operatively to 36 at follow-up.

The migration percentage and centre-edge angle were assessed on plain radiographs. Radiological containment improved, the mean migration percentage improved from 50 pre-operatively to 20 at follow-up and the mean centre-edge angle improved from −5° to 29°.

No statistical difference was noted between the three-year and ten-year follow-up results, indicating that the improvements in clinical and radiological outcome had been maintained.

This paper describes the technique and results of an acetabuloplasty in which the false acetabulum is turned down to augment the dysplastic true acetabulum at its most defective part. This operation was performed in 17 hips (16 children), with congenital dislocation and false acetabula. The mean age at operation was 5.1 years (4 to 8). The patients were followed clinically and radiologically for a mean of 6.3 years (5 to 10). A total of 16 hips had excellent results and there was one fair result due to avascular necrosis. The centre-edge angles and the obliquity of the acetabular roof improved in all cases, from a mean of −15.9° (−19° to 3°) and 42.6° (33° to 46°) to a mean of 29.5° (20° to 34°) and 11.9° (9° to 19°), respectively. The technique is not complex and is stable without internal fixation. It provides a near-normal acetabulum that requires minimal remodelling, and allows early mobilisation.

In order to treat painful subluxation or dislocation secondary to cerebral palsy, 11 patients (12 hips) underwent combined femoral and Chiari pelvic osteotomies with additional soft-tissue releases at a mean age of 14.1 years (9.1 to 17.8). Relief of pain, improvement in movement of the hip, and in sitting posture, and ease of perineal care were recorded in all, and were maintained at a mean follow-up of 13.1 years (8 to 17.5). The improvement in general mobility was marginal, but those who were able to walk benefited the most.

The radiological measurements made before operation were modified afterwards to use the lateral margin of the neoacetabulum produced by the pelvic osteotomy. The radiological migration index improved from a mean of 80.6% (61% to 100%) to 13.7% (0% to 33%) (p < 0.0001). The mean changes in centre edge angle and Sharp’s angle were 72° (56° to 87°; p < 0.0001) and 12.3° (9° to 15.6°; p < 0.0001), respectively. Radiological evidence of progressive arthritic change was seen in one hip, in which only a partial reduction had been achieved, and there was early narrowing of the joint space in another. Painless heterotopic ossification was observed in one patient with athetoid quadriplegia. In seven hips the lateral Kawamura approach, elevating the greater trochanter, provided exposure for both osteotomies and allowed the construction of a dome-shaped iliac osteotomy, while protecting the sciatic nerve.

Difficulties posed in managing developmental dysplasia of the hip diagnosed late include a high-placed femoral head, contracted soft tissues and a dysplastic acetabulum. A combination of open reduction with femoral shortening of untreated congenital dislocations is a well-established practice. Femoral shortening prevents excessive pressure on the located femoral head which can cause avascular necrosis. Instability due to a coexisting dysplastic shallow acetabulum is common, and so a pelvic osteotomy is performed to achieve a stable and concentric hip reduction. We retrospectively reviewed 15 patients (18 hips) presenting with developmental dysplasia of the hip aged four years and above who were treated by a one-stage combined procedure performed by the senior author. The mean age at operation was five years and nine months (4 years to 11 years). The mean follow-up was six years ten months (2 years and 8 months to 8 years and 8 months). All patients were followed up clinically and radiologically in accordance with McKay’s criteria and the modified Severin classification. According to the McKay criteria, 12 hips were rated excellent and six were good. All but one had a full range of movement. Eight had a limb-length discrepancy of about 1 cm. All were Trendelenburg negative. The modified Severin classification demonstrated four hips of grade IA, six of grade IB, and eight of grade II. One patient had avascular necrosis and one an early subluxation requiring revision. One-stage correction of congenital dislocation of the hip in an older child is a safe and effective treatment with good results in the short to medium term

A total of 47 non-walking patients (52 hips) with severe cerebral palsy and with a mean age of 14 years, (9 to 27) underwent a Dega-type pelvic osteotomy after closure of the triradiate cartilage, together with a derotation varus-shortening femoral osteotomy and soft-tissue correction for hip displacement which caused pain and/or difficulties in sitting. The mean follow-up was 48 months (12 to 153). The migration percentage improved from a pre-operative mean of 70% (26% to 100%) to 10% (0% to 100%) post-operatively. In five hips the post-operative migration percentage was greater than 25%, which was associated with continuing pain in two patients. Three patients had persistent hip pain and a migration percentage less than 25%. In five hips a fracture through the acetabulum occurred, and in another there was avascular necrosis of the superior acetabular segment, but these had no adverse effect on functional outcome. We conclude that it is possible to perform a satisfactory pelvic osteotomy of this type in these patients after the triradiate cartilage has been closed.

Avascular necrosis is a serious complication of slipped capital femoral epiphysis and is difficult to treat. The reported incidence varies from 3% to 47% of patients. The aims of treatment are to maintain the range of movement of the hip and to prevent collapse of the femoral head. At present there are no clear guidelines for the management of this condition and treatment can be difficult and unrewarding.

We have used examination under anaesthesia and dynamic arthrography to investigate avascular necrosis and to determine the appropriate method of treatment. We present 20 consecutive cases of avascular necrosis in patients presenting with slipped capital femoral epiphysis and describe the results of treatment with a mean follow-up of over eight years (71 to 121 months). In patients who were suitable for joint preservation (14), we report a ten-year survivorship of the hip joint of 75% and a mean Harris hip score of 82 (44 to 98).