Closed reduction and dynamic cast immobilization in patients with developmental dysplasia of the hip between 6 and 24 months of age

Bony hip reconstruction for displaced hips in patients with cerebral palsy: Is postoperative immobilization indicated?

Purpose

Decisions for postoperative immobilization after bony hip reconstructive surgery in cerebral palsy are controversial in current practice. The aim of this study was to check if choosing not to use any kind of postoperative immobilization is a safe practice.

Methods

A retrospective cohort study was conducted in a pediatric orthopedic tertiary referral center. The study included 148 patients (228 hips) with cerebral palsy, who had bony hip surgery. Medical records were reviewed for incidence of complications, methods of pain control, and length of hospital stay. Three radiographic measures (neck-shaft angle, Reimers migration index, and acetabular index) were performed on preoperative and postoperative X-rays. X-rays were also checked for mechanical failure of implant, recurrent dislocation/subluxation, and fractures in the first 6 months postoperatively.

Results

In total, 94 (64%) were male and 54 (36%) were female. Seventy-seven (52%) were Gross Motor Function Classification System V, mean age at surgery was 8.6 years (2.5-18.4 years). Length of hospital stay was 6.25 days (SD 4.64 days). Medical complications that may have prolonged hospital stay occurred in 41 patients (27.7%). Radiological measurements showed significant improvement postoperatively (p = 0.001). Seven patients (4.7%) had another surgery in first 6 months (three for recurrent dislocation/subluxation, three for implant failure, and one for ipsilateral femur fracture).

Conclusion

Avoiding postoperative immobilization following bony hip surgery in cerebral palsy is a safe practice and associated with reduced rate of medical and mechanical problems compared to the current literature. This approach should be utilized with optimal pain and tone management.

Anteroposterior pelvic radiograph is not sufficient to confirm hip reduction after conservative treatment of developmental dysplasia of the hip

The purpose of this study was to investigate whether an anteroposterior pelvic radiograph alone is sufficient to confirm hip reduction after conservative treatment or whether MRI could be alternatively performed. A total of 133 children (145 hips) were enrolled. All children were examined by anteroposterior pelvic radiographs and MRI. Three experts interpreted anteroposterior pelvic radiographs and then verified these results on MRI. For patients with inconsistent results between anteroposterior pelvic radiographs and MRI, the continuity of Shenton's line and Calve's line was recorded, and the medial clear space of bilateral hips was measured for unilateral cases. There was complete agreement between the three experts in the interpretation of anteroposterior pelvic radiographs of 111 (76.55%) hips; there was disagreement in the remaining 34 hips, with two experts diagnosing satisfactory reduction in 13 hips and dislocation in 21 hips. Assuming that the judgment of two or more doctors on anteroposterior pelvic radiographs was taken as the final result, 17 hips (11.72%) were misjudged. There was no statistically significant difference between the actual in-position group and the actual dislocation group in terms of the continuity of Shenton's line ( P  = 0.62) and Calve's line ( P  = 0.10) and the medial clear space of bilateral hips ( P  = 0.08). In children less than 1 year of age with developmental dysplasia of the hip treated conservatively, the use of anteroposterior pelvic radiographs alone to judge hip reduction might result in misdiagnosis and missed diagnosis. MRI could be alternatively used to detect hip reduction after conservative treatment, especially when the doctor was not familiar with ultrasound in the presence of plaster.

Outcome Prognostic Factors in MRI during Spica Cast Therapy Treating Developmental Hip Dysplasia with Midterm Follow-Up

Closed reduction followed by spica casting is a conservative treatment for developmental dysplasia of the hip (DDH). Magnetic resonance imaging (MRI) can verify proper closed reduction of the dysplastic hip. Our aim was to find prognostic factors in the first MRI to predict the possible outcome of the initial treatment success by means of ultrasound monitoring according to Graf and the further development of the hip dysplasia or risk of recurrence in the radiological follow-up examinations. A total of 48 patients (96 hips) with DDH on at least one side, and who were treated with closed reduction and spica cast were included in this retrospective cohort study. Treatment began at a mean age of 9.9 weeks. The children were followed for 47.4 months on average. We performed closed reduction and spica casting under general balanced anaesthesia. This was directly followed by MRI to control the position/reduction of the femoral head without anaesthesia. The following parameters were measured in the MRI: hip abduction angle, coronal, anterior and posterior bony axial acetabular angles and pelvic width. A Graf alpha angle of at least 60° was considered successful. In the radiological follow-up controls, we evaluated for residual dysplasia or recurrence. In our cohort, we only found the abduction angle to be an influencing factor for improvement of the DDH. No other prognostic factors in MRI measurements, such as gender, age at time of the first spica cast, or treatment involving overhead extension were found to be predictive of mid-term outcomes. This may, however, be due to the relatively small number of treatment failures.

Retrospective Comparison of Outcomes Between Closed and Open Reduction for Developmental Dysplasia of the Hip in Children Aged 6-24 Months

PURPOSE

We aimed to compare the outcomes between closed reduction (CR) and open reduction (OR) in children aged 6-24 months with developmental dysplasia of the hip (DDH) who could be reduced safely and stably by the closed reduction operation.

METHODS

We retrospectively reviewed the medical records of 77 patients who underwent CR or OR for DDH. Fifty-one patients (56 hips) underwent CR, 26 (29 hips) underwent OR. The demographic data, International Hip Dysplasia Institute classification and acetabular index (AI) before reduction and the centre-edge angle (CEA), AI, Alsberg angle (AA), Reimer's migration index (RMI), and height-to-width index (HWI) of the epiphysis were compared between two groups at the final follow-up. The percentage of coxa magna > 15% of the normal side and AA > 81° were calculated.

RESULTS

At the final follow-up, the mean AA in the CR and OR groups were 77.66° (60°-89°) and 81.97° (73°-91°) (p = 0.001), respectively, there were 32.14% and 58.62% of the hips with an AA > 81° (p = 0.019). The frequency of coxa magna > 15% of the normal side was higher in the OR group (60.9%) than in the CR group (6.5%) (p < 0.001). There was no difference in the improvement of AI, CEA, HWI, and RMI.

CONCLUSION

In children aged 6-24 months with DDH, if a stable and safe CR can be obtained but with medial joint space up to 6mm, CR should be attempted first.

Short versus Long-Leg Hip Spica After Closed Reduction in Developmental Dysplasia of the Hip: A Retrospective Comparative Study

Purpose

Closed reduction (CR) is a standard treatment for developmental dysplasia of the hip (DDH) after failed conservative treatment. After CR, the affected hip is held in the reduced position by a spica cast that typically extends below the knee (long). Above knee (short) spica cast is an alternative technique utilized by some pediatric orthopedic surgeons. We aimed to compare short versus long spica cast after CR in terms of success rate and complications.

Methods

Patients who underwent CR with short or long hip spica cast over a 3-year period (2016–2019) were evaluated for the success (sustainability of the reduction) and complications. The acute and long-term success were recorded retrospectively. Acute success was defined as concentric reduction of the hip confirmed by intraoperative arthrogram and immediate postoperative CT scan. Long-term success was defined as maintained reduction at 12 months’ post reduction.

Results

Forty-seven patients were included in our study. Long spica casts were used in 24 patients and short ones in the remaining 23. The overall acute and long-term success rates were 83% and 66%, respectively. The acute success rate of long spica was 87.5%, while short spica achieved 78.2%. On the long term, the success rate of short spica was higher than long one (73.9% vs 58.3%). Cox regression analysis showed that the type of cast (short vs long spica) was not correlated with acute success (P = 0.405), long-term success (P = 0.263), residual dysplasia (P = 0.405), or avascular necrosis (P = 0.053).

Conclusion

CR in DDH is an important line of management in the younger patient population and can save them an invasive open surgery later in life. A short leg spica could represent an easier and likely as successful alternative to the traditional long spica. More prospective future research is needed to validate our observational findings.

Level of Evidence

III.

Does the vascular development of the femoral head correlate with the incidence of avascular necrosis of the proximal femoral epiphysis in children with developmental dysplasia of the hip treated by closed reduction?

PURPOSE

The purpose of this study was to identify the correlation between the vascular development of the femoral head and avascular necrosis (AVN) in patients with developmental dysplasia of the hip (DDH) treated by closed reduction (CR).

METHODS

We retrospectively reviewed 78 patients with DDH treated by CR (83 hips). The vascular maturity, number of vessels and perfusion changes of the femoral head were assessed on perfusion MRI (pMRI) before and after CR.

RESULTS

The number of vessels (mean 4.2 sd 1.4) of the femoral head and the ratio (36.1%) of mature vessels (type III) on the dislocated side were significantly less than those at contralateral side (mean 6.0 sd 1.2; 82.2%) (p < 0.001). Of the included 83 hips, 39 hips (61.5%) showed decreased perfusion of the femoral head, including partial decreased (Class B, 47.0%) and global decreased (Class C, 14.5%), at the dislocated side, which was significantly more than those at contralateral side (0.0%) (p < 0.001). In total, 32 out of 83 hips (38.5%) developed AVN. The rate of AVN with Class A (18.8%) which perfusion of the femoral head was normal (unchanged or enhanced) was significantly less than those with Class C (66.7%) (p = 0.006).

CONCLUSION

The vascular development and perfusion changes of the femoral head on the dislocated side are significantly worse than those at contralateral side. Immature vascularity of the femoral head before CR and poor perfusion of the femoral head after CR may be risk factors for AVN in patients with DDH.

LEVEL OF EVIDENCE

III.

The incidence of avascular necrosis following a cohort of treated developmental dysplasia of the hip in a single tertiary centre

PURPOSE

Avascular necrosis (AVN) may occur following treatment for developmental dysplasia of the hip (DDH). The primary aim of this study was to identify the incidence of AVN in a cohort of patients treated for DDH. Secondary aims were to classify AVN using available classification systems, analyze the correlation between the systems and investigate their relationship with the age at diagnosis of DDH.

METHODS

An 11-year retrospective study was carried out at a single tertiary centre, using data from the clinical portal (patient records database) and IMPAX (system used to store plain radiographic images). Clinical details (patient demographics and outcomes) and plain radiographic images were used to identify cases of DDH and categorize cases of AVN using available classification systems: Tonnis and Kuhlmann, Kalamchi and McEwen, Bucholz and Ogden and Salter. Severin was used to assess final clinical outcome.

RESULTS

In total, 405 (522 hips) cases of DDH were identified, of which 213 resolved without treatment, 93 were treated conservatively and 99 surgically. Only treated cases were included in the analysis (n = 192). AVN (45/99; 45.5%) was found to occur only postoperatively. A positive correlation was present between age at presentation and severity of AVN as classified according to Salter's criteria (chi-squared p value < 0.01).

CONCLUSION

AVN incidence was 23.4% (45/192) and only occurred in surgically treated patients. Older age at diagnosis was associated with a higher incidence of AVN, as defined according to Salter's criteria. The classification systems appeared to show no correlation amongst each other (p-value < 0.01).

LEVEL OF EVIDENCE

III - Retrospective cohort study.

Effect of age on radiographic outcomes of patients aged 6-24 months with developmental dysplasia of the hip treated by closed reduction

This study aimed to investigate the effect of age on the rates of redislocation, avascular necrosis (AVN) of the femoral head, and final radiographic outcomes in patients with developmental dysplasia of the hip (DDH) treated with closed reduction. A total of 308 hips (276 patients) with DDH treated with closed reduction were included and divided into three groups according to age (<12, 12-18, 18-24 months). Tönnis grade, rate of redislocation and AVN, Severin radiographic grade, and risk of surgery were evaluated on radiographs. Tönnis grade significantly increased with age (P < 0.001). Redislocation occurred in 17 (5.5%) and AVN occurred in 36 (11.7%) hips. The rate of redislocation and AVN was similar among the three age groups in all Tönnis grades. However, redislocation rate significantly increased with Tönnis grade (P = 0.027). Overall, 246 hips (79.9%) had satisfactory final outcomes, and 62 hips (20.1%) had unsatisfactory outcome; no difference was observed among three age groups. A total of 103 hips (33.4%) were found to be at risk for secondary surgery. The surgical risk (25%) in patients younger than 12 months was lower than that of older patients (12-18 months: 34.4%; 18-24 months: 37.9%). Logistic regression analysis also confirmed that age was not a risk factor for redislocation, AVN, or poor radiographic outcome. In conclusion, age has no significant impact on redislocation and AVN in patients aged 6-24 months with DDH treated by closed reduction. Although older patients have a higher risk developing residual acetabular dysplasia, secondary pelvic surgery provides favorable outcomes in most patients.

Surgical management of the congenital dislocation of the knee and hip in children presented after six months of age

PURPOSE

Congenital dislocation of the knee and hip is a rare congenital disorder. The specific aim of the study was to evaluate the clinical and radiological outcomes of the children with congenital dislocation of the knee and hip who presented after six months of age.

METHODS

All the consecutive children with congenital dislocation of the knee and hip joints were retrospectively reviewed. We included cases that were treated after six months of age and followed up for a minimum of two years. Twenty-four children with congenital dislocation of the knee and hip (thirteen with ligamentous laxity, eleven children with stiff joints) were included. The knee was dislocated in 45 limbs; the hip was dislocated in 40 instances. The knee joint dislocation was treated with quadricepsplasty in all twenty-four children (45 knees). The hip dislocation (n = 32) was addressed with either closed reduction (n = 8) or open reduction of the hip (n = 24). Eight hip dislocations were not addressed. The outcome of the hip and knee was evaluated.

RESULTS

The clinical and radiological outcomes were better in children with ligamentous laxity than without laxity. Twenty-two children were community walkers. An orthosis was needed in eight children. The frequency of spontaneous reduction of unreduced dislocation of the hip was noted in three children (5/8 hips).

CONCLUSION

Outcome in combined dislocation of knee and hip is good in most cases with surgical interventions. The outcome is better in children with ligamentous laxity. Spontaneous reduction of the dislocated hips might be achieved after gaining knee flexion following knee surgery for congenital the knee in a few cases.

Does the size of the femoral head correlate with the incidence of avascular necrosis of the proximal femoral epiphysis in children with developmental dysplasia of the hip treated by closed reduction?

PURPOSE

The purpose of this study was to identify if any correlation between size of the proximal femoral epiphysis and avascular necrosis (AVN) exists.

METHODS

We retrospectively reviewed 111 patients with developmental dysplasia of the hip treated by closed reduction (124 hips). The diameter and height of both femoral head and ossific nucleus were assessed on preoperative MRI.

RESULTS

The diameter and the height of the femoral head as well as of the ossific nucleus of the contralateral side were significantly greater than the dislocated side. AVN occurred in 21 (16.9%) out of 124 hips. The rate of AVN gradually decreased with age: 30.0% at six to 12 months, 18.2% at 12 to 18 months and 3.7% at 18 to 24 months. Spearman correlation analysis showed that age is negatively correlated with the incidence of AVN (r = -0.274; p = 0.002) and the diameter of the femoral head has a significantly negative association with the incidence of AVN (r = -0.287; p = 0.001). No significant association was observed between the incidence of AVN and height of the femoral head or size of the ossific nucleus. Hips with AVN were significantly smaller than hips without AVN.

CONCLUSIONS

The size of both the femoral head and the ossific nucleus increase with age although the dislocated femoral head is smaller compared with the contralateral side. The diameter of the femoral head and not the size of the ossific nucleus negatively correlate with the risk of AVN, with a bigger femoral head showing lower risk of AVN.

LEVEL OF EVIDENCE

III.

Variables influencing the pelvic radiological evaluation in children with developmental dysplasia of the hip managed by closed reduction: a multicentre investigation

PURPOSE

This study aims to evaluate (1) the probability to achieve normal pelvic radiographs in children with developmental dysplasia of the hip (DDH) treated by closed reduction and (2) the amount of time needed to achieve normal pelvic radiographs and to assess what factors influence both probability and time to achieve normal radiographic parameters following CR and spica cast immobilization for DDH.

METHODS

We retrospectively reviewed 436 patients (393 girls, 43 boys; 507 hips) with DDH treated by closed reduction (CR). Tönnis grade, AVN, acetabular index (AI), centre-edge angle (CEA), and Severin radiographic grade were evaluated on plain radiographs. Criteria to rate pelvis radiographs as normal were established. Cox regression was used to evaluate the factors influencing the probability and the time to achieve normal radiographs.

RESULTS

According to our criteria, 167 hips (32.9%) achieved normal radiographic parameters during follow-up. The overall amount of time to achieve normal pelvis radiographs was 36.1 ± 15.5 months. Patients older than 24 months of age at the time of CR needed longer time to achieve normal radiographic parameters (55.2 ± 28 months) compared with other age groups. Cox regression analysis suggested the overall cumulative probability of recovery increased by 46% at five years following CR, then it tended to plateau with an annual increase less than 5%. Age older than 24 months, bilateral dislocation, pre-operative AI greater than 40°, and AVN were risk factors for reduced probability of achieving normal radiographic parameters.

CONCLUSIONS

The cumulative probability of achieving normal pelvis radiographs increases linearly during the first five years following CR, then it tends to plateau. Age older than 24 months and Tönnis grade III and IV are associated with longer time to achieve normal radiographic parameters. Age older than 24 months, bilateral dislocation, pre-operative AI greater than 40°, and AVN are risk factors for reduced probability of achieving normal radiographic parameters in children with DDH treated by closed means.

Effect of abduction on avascular necrosis of the femoral epiphysis in patients with late-detected developmental dysplasia of the hip treated by closed reduction: a MRI study of 59 hips

PURPOSE

The purpose of this study was to explore whether increasing the hip abduction angle would increase the incidence of avascular necrosis (AVN) in patients with late- detected developmental dysplasia of the hip (DDH) treated by closed reduction (CR) and spica cast immobilization.

METHODS

A total of 55 patients (59 hips) with late-detected DDH underwent MRI after CR. Hip abduction angle and hip joint distance were measured on postoperative MRI transverse sections. The acetabular index and centre-edge angle were measured on plain radiographs at the last follow-up. The presence of AVN according to Kalamchi and McEwen's classification was assessed. We retrospectively analyzed the associations among abduction angles, hip joint distances, radiographic parameters, AVN and final outcomes, exploring the relationship between hip joint abduction angle and AVN rate.

RESULTS

The mean age at the time of CR was 14.4 months SD 5.5 (6 to 28), and the mean follow-up was 26.2 months SD 8.1 (12.4 to 41.7). The mean hip abduction angle was 70.2° SD 7.2° (53° to 85°) on the dislocated side and 63.7° SD 8.8° (40° to 82°) on the normal side; the mean hip joint distance was 5.1 mm SD 1.9 (1.3 to 9.1) on the dislocated side and 2.2 mm SD 0.6 on the normal side (1.3 to 3.3). Eight of 59 hips (13.6%) developed AVN. Neither the amount of abduction nor hip joint distance increased the AVN rate (p = 0.97 and p = 0.65, respectively) or the dislocation rate (p = 0.38 and p = 0.14, respectively).

CONCLUSION

Abduction angle up to 70.2° following CR did not increase the AVN rate in children aged six to 28 months with late-detected DDH treated by CR.

LEVEL OF EVIDENCE

III.

[Hip dysplasia-new and proven methods]

BACKGROUND

Hip dysplasia is one of the most common disorders in paediatric orthopedics. With the development of ultrasound techniques treatment has changed, and earlier diagnosis and treatment is possible. So, for more than 20 years diagnosis and treatment has been focused on ultrasound. Many papers reporting new diagnostic techniques like MRI have been published. Arthroscopic reduction is a new surgical procedure. However, established surgical procedures continue to play an important role in the treatment.

CURRENT TREATMENT

This paper presents new and established diagnostic techniques, conservative and surgical treatment options. Unfortunately, due to the great number of publications, not all aspects could be taken into account. In particular, we describe the diagnostic and treatment standards in German-speaking countries based on ultrasound hip screening. However, also international aspects of diagnostic and treatment options have been included.