What Do We Really Know About the Natural History of Spastic Hip Dysplasia and Pain in Total-involvement Cerebral Palsy? A Systematic Review

BACKGROUND

Hip surveillance protocols and surgery for spastic hip dysplasia have become standard of care for children with cerebral palsy (CP) out of concern for long-term sequelae, including pain. It is unclear if available data support that spastic hip dysplasia/dislocation independently correlates with pain in total-involvement CP. A better understanding of this correlation may help guide decision-making for these medically complex patients.

METHODS

We undertook a systematic literature review to assess published data on the association of spastic hip dysplasia and pain in total-involvement CP using PubMed (which includes the MedLine databases) and EMBASE databases. A total of 114 English-language articles were identified. Fifteen articles met the inclusion criteria and were evaluated using the PRISMA guidelines for systematic reviews.

RESULTS

Of 15 articles that specifically assessed the association of spastic hip dysplasia and pain, 5 articles provided strong evidence per our criteria regarding the correlation of pain and spastic hip dysplasia. All 5 articles described the severity of CP in their studied population, radiographically defined hip displacement, included a control group, and described how pain was assessed. Nevertheless, there was no standard classification of dysplasia between studies and the ages of patients and methods of pain determination varied. Four of the articles provided level III evidence and one provided level II evidence. Of these 5 articles with the strongest available evidence, data from 2 did not support a correlation between hip dysplasia and hip pain, 2 supported a correlation, and 1 was equivocal.

CONCLUSIONS

Even the best available evidence on spastic hip dysplasia and pain reveals no consensus or conclusion on whether spastic hip dysplasia and dislocation in total-involvement CP is independently correlated with pain.

LEVEL OF EVIDENCE

Level III-Prognostic study.

A 30-year follow-up study of rotational acetabular osteotomy for pre- and early-stage osteoarthritis secondary to dysplasia of the hip

Aims

The objective of this study was to present the outcomes of rotational acetabular osteotomy (RAO) over a 30-year period for osteoarthritis (OA) secondary to dysplasia of the hip in pre- or early-stage OA.

Methods

Between September 1987 and December 1994, we provided treatment to 47 patients (55 hips) with RAO for the management of pre- or early-stage OA due to developmental hip dysplasia. Of those, eight patients (11 hips) with pre-OA (follow-up rate 79%) and 27 patients (32 hips) with early-stage OA (follow-up rate 78%), totalling 35 patients (43 hips) (follow-up rate 78%), were available at a minimum of 28 years after surgery.

Results

In the pre-OA group, the mean Merle d'Aubigné score improved significantly from 14.5 points (SD 0.7) preoperatively to 17.4 points at final follow-up (SD 1.2; p = 0.004) and in the early-stage group, the mean score did not improve significantly from 14.0 (SD 0.3) to 14.6 (SD 2.4; p = 0.280). Radiologically, the centre-edge angle, acetabular roof angle, and head lateralization index were significantly improved postoperatively in both groups. Radiological progression of OA was observed in two patients (two hips) in the pre-OA group and 17 patients (18 hips) in the early-stage group. Kaplan-Meier survival analysis, with radiological progression of OA as the primary outcome, projected a 30-year survival rate of 81.8% (95% confidence interval (CI) 0.59 to 1.00) for the pre-OA group and 42.2% (95% CI 0.244 to 0.600) for the early-stage group. In all cases, the overall survival rate stood at 51.5% (95% CI 0.365 to 0.674) over a 30-year period, and when the endpoint was conversion to total hip arthroplasty, the survival rate was 74.0% (95% CI 0.608 to 0.873).

Conclusion

For younger patients with pre-OA, joint preservation of over 30 years can be expected after RAO.

Congenital dislocation of the knee complicated with bilateral hip dislocation: a case report and literature review

BACKGROUND

Congenital dislocation of the knee is characterised by excessive knee extension or dislocation and anterior subluxation of the proximal tibia, and this disease can occur independently or coexist with different systemic syndromes. Nevertheless, significant controversy surrounds treating this disease when combined with hip dislocation. This paper presents a case of a 4-month-old patient diagnosed with bilateral hip dislocation combined with this disease. The study discusses the pathophysiology, diagnosis, and treatment methods and reviews relevant literature.

CASE PRESENTATION

We reported a case of a 4-month-old female infant with congenital dislocation of the right knee joint, which presented as flexion deformity since birth. Due to limitations in local medical conditions, she did not receive proper and effective diagnosis and treatment. Although the flexion deformity of her right knee joint partially improved without treatment, it did not fully recover to normal. When she was 4 months old, she came to our hospital for consultation, and we found that she also had congenital dislocation of both hip joints and atrial septal defect. We performed staged treatment for her, with the first stage involving surgical intervention and plaster orthosis for her congenital dislocation of the right knee joint, and the second stage involving closed reduction and plaster fixation orthosis for her congenital hip joint dislocation. Currently, the overall treatment outcome is satisfactory, and she is still under follow-up observation.

CONCLUSIONS

Early initiation of treatment is generally advised, as nonsurgical methods prove satisfactory for mild cases. However, surgical intervention should be considered in cases with severe stiffness, unresponsive outcomes to conservative treatment, persistent deformities, or diagnoses and treatments occurring beyond the first month after birth.

Mid-term results of total hip arthroplasty with anatomical ultra-short cementless stem in patients with developmental dysplasia of the hip Crowe type II

The aim of this study was to present the mid-term results of ultra-short cementless stem total hip arthroplasty (THA) in patients with Crowe type II developmental dysplasia of the hip. The study consists of 68 patients (75 THAs) with a Proxima stem implanted between 2006 and 2015. The clinical results include Harris Hip Scores. Radiological follow-up reports on stem migration, bony trabecular development and radiolucent lines. Kaplan-Meier survival analysis was performed. The mean age of patients was 48.4 years, with a mean follow-up 114 months. The average Harris Hip Score improved significantly from 45.1 preoperatively to 97.6 at the final evaluation (p < 0.001). Stem migration was observed in five hips (in all of them up to the 6th postoperative month, without any further progression of migration or radiological loosening). Bony trabecular development was detected in modified Gruen zones (1, 2, 4, 6, 7 for Proxima stem): in zone 1 (0%), 2 (49.3.0%), 4 (38.7%), 6 (82.7%), 7 (0%). Radiolucent lines were observed around one cup (DeLee and Charnley zone I) and three stems (none was loose, all three with fibrous stable fixation). Complications were found in three hips (4.0%): intraoperative periprosthetic femoral fracture (threated with cerclage wire) in two hips and squeezing hip in one patient (with perioperative ceramic inlay breakage and exchange). No hip was revised. The implant survival was 100.0% both clinically and radiologically. Observations in the mean follow-up of 114 months show that the results (clinical and radiological) of the Proxima stem in patients with Crowe type II DDH are promising.

Recovery in Hip Range of Motion in Young Flexibility Athletes 1 Year After Periacetabular Osteotomy

Background: Periacetabular Osteotomy (PAO) is a well-established surgical intervention for the treatment of hip dysplasia. Purpose: Our primary objective was to assess whether a group of young flexibility athletes who underwent PAO for hip dysplasia recovered their pre-operative hip range of motion (ROM) within 1 year of surgery. Our secondary objective was to compare hip ROM recovery between a group of young flexibility athletes and a group of non-flexibility athletes who underwent PAO for hip dysplasia. Results: In our study, 100% of flexibility athletes regained preoperative hip external rotation at 1-year post-operation. This was also the first plane of motion to return to preoperative motion in flexibility athletes. A significantly higher percentage of non-flexibility athletes regained their preoperative hip internal rotation compared to flexibility athletes (100% compared to 54%; P = .02), but not flexion or external rotation at 1-year post-operation. Conclusion: Our findings may help providers to set expectations regarding the recovery of hip ROM in flexibility athletes who undergo PAO for hip dysplasia.Level of Evidence: Level IV.

Long-term course of developmental dysplasia of the hip: follow-up of the non-operated hips of patients undergoing unilateral rotational acetabular osteotomy for twenty-four years

PURPOSE

To follow-up the non-operated hips of patients who underwent unilateral rotational acetabular osteotomy (RAO) for bilateral developmental dysplasia of the hip (DDH) for a minimum of 20 years to clarify (1) the timing of onset of hip osteoarthritis (OA) in DDH, and (2) factors associated with the development of OA.

METHODS

This study included 92 non-operated hips of patients who underwent unilateral RAO for bilateral DDH. We examined the timing of OA onset and total hip arthroplasty (THA) and the joint survival rate in the studied hips. Furthermore, the patients were divided into those with OA onset (progression group) and those without OA onset and compared in terms of lateral center-edge angle (LCEA), sharp angle, acetabular head index (AHI), acetabular roof obliquity (ARO), joint congruity, and the presence or absence of OA progression on the RAO side.

RESULTS

The progression group experienced OA onset 12 years after RAO and underwent THA 6 years after OA onset. The 20-year joint survival rate was 73% with the endpoint of OA onset and 81% with the endpoint of THA. The progression group had significantly smaller LCEA and AHI and larger ARO. The risk of developing OA was 8.2 times greater in patients with LCEA ≤ 7° than in those with LCEA > 7°.

CONCLUSION

The patients with OA progression group experienced OA onset at an average age of 55 years. A small LCEA (≤ 7°) was identified as a risk factor for the development of OA.

Current concepts in the diagnosis and management of Os Acetabuli

PURPOSE

The aim of this review is to appraise the current evidence on the epidemiology, pathophysiology, diagnosis and management of os acetabuli.

METHODS

A scoping review was conducted according to the Joanna Briggs Institute guidelines. A systematic search was performed on Medline (PubMed), Embase and Cochrane Library. Inclusion criteria comprised observational and interventional studies and review articles published in the English language that focused on patients with os acetabuli according to the PRISMA extension of scoping reviews checklist using the terms 'Os Acetabuli' or 'os acetabula' or 'acetabular ossicles'. A narrative synthesis of results was undertaken, and the included articles were divided into (i) definition, (ii) aetiology, (iii) diagnosis and imaging and (iv) management of os acetabuli.

RESULTS

107 articles were screened, with 22 meeting the eligibility criteria. A total of 8836 patients were considered, of which 604 had os acetabuli. The mean age was 32.8 years. The prevalence of os acetabuli ranged from 3.4 to 7.7%, with a higher prevalence in males compared to females. True os acetabuli was defined as an unfused secondary ossification centre along the acetabular rim. The aetiology of os acetabuli is thought to be secondary to acetabular dysplasia and/or femoroacetabular impingement. Standard of care for management of symptomatic os acetabuli is considered to be arthroscopic excision unless the excision results in acetabular undercoverage and/or instability, in which case, fixation is recommended.

CONCLUSIONS

Successful management of os acetabuli depends on understanding the pathology and treating the underlying cause rather than treating the os acetabuli in isolation. Future work needs to focus on establishing clear diagnostic criteria, consensus on definition and an evidence-based treatment algorithm.

Nurses assessment of development hip dysplasia: A scoping review

Developmental hip dysplasia is an abnormality of the hip joint which is associated with an unstable or dislocatable hip. During infancy, hips should be screened to determine whether they are stable, unstable or dislocated. In Australia, this screening is often performed by nurses using physical assessment. Physical examination includes a number of assessments which seek to identify underlying abnormalities in hip joint anatomy and function. This scoping review outlines the physical assessments used by nurses in the screening and surveillance of developmental hip dysplasia. A review of the literature identified 15 (N = 15; 100%) sources of evidence, which included original research articles (n = 6; 40%), expert opinion pieces (n = 2; 13.3%) and practice guidelines (n = 7; 46.7%). There were 18 physical assessments identified as being used by nurses in the screening process for developmental hip dysplasia. However, it is apparent that high quality research is required to examine the timing, specificity and sensitivity of the physical assessments identified.

Editorial Commentary: Concomitant Hip Arthroscopy and Periacetabular Osteotomy Treat Both the Cause and the Effects of Hip Dysplasia: The Best of Both Worlds

In the management of true hip dysplasia, the bony deformity is nearly always accompanied by, and often causal of, intra-articular pathology. It is strongly recommended to conduct a comprehensive preoperative evaluation as well as arthroscopic evaluation and treatment of coexisting hip joint conditions prior to performing an open Bernese periacetabular osteotomy. The osteotomy improves coverage of the femoral head and corrects the abnormal joint mechanics and loading patterns, which result in cartilage damage and subsequent osteoarthritis. Arthroscopy allows treatment of the intra-articular pathology. Combining the hip arthroscopy and periacetabular osteotomy procedures into a single surgical intervention, performed by either a single surgeon or a collaborative surgical team, allows us to address both the cause and the effects of dysplasia. This once-controversial combined technique has become a standard practice in the field with widespread adoption.

Surgical Treatment of Late Developmental Dysplasia of the Hip in Bladder Exstrophy: A Case Report

CASE

We present a case of an 8-year-old boy with classical bladder exstrophy and a neglected right hip dislocation, exemplifying the risk of missed developmental dysplasia of the hip (DDH) in patients with exstrophy requiring careful orthopaedic oversight.

CONCLUSIONS

When treating patients with bladder exstrophy, physicians and surgeons should be vigilant not to miss associated DDH. If this condition requires surgical treatment, preoperative planning with computed tomography scans is vital to uncovering the complexities arising from abnormal pelvic and acetabular anatomy and ensuring successful treatment outcomes.

The outcomes of total hip arthroplasty in developmental dysplasia of hip versus osteoarthritis: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to compare the outcomes of total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH) and those with osteoarthritis (OA).

METHODS

Four databases were searched from inception till February 2023 for original studies that compared the outcomes of THA in DDH and OA. The primary outcome was the revision rate; the secondary outcomes were dislocation and failure modes (i.e. aseptic loosening, PJI, instability, and periprosthetic fractures), hospital stay and costs. This review was conducted as per PRISMA guidelines, and the risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

A total of 9 observational studies with 575,255 THA (469,224 hips) were included, with a mean age of 50.6 years and 62.1 years for DDH and OA groups, respectively. There was a statistically significant difference in revision rate between DDH and OA patients in favour of OA (OR, 1.66; 95% CI 1.11-2.48; p-value, 0.0251). However, dislocation rate (OR, 1.78, 95% CI 0.58-5.51; p-value, 0.200), aseptic loosening (OR, 1.69; 95% CI 0.26-10.84; p-value, 0.346) and PJI (OR, 0.76; 95% CI 0.56-1.03; p-value, 0.063) were comparable across both groups.

CONCLUSION

A higher revision rate following total hip arthroplasty was associated with DDH compared with osteoarthritis. However, both groups had similar dislocation rates, aseptic loosening and PJI. Consideration of confounding factors, such as patient age and activity level, is crucial when interpreting these findings. LEVEL OF EVIDENCE : III.

TRIAL REGISTRATION

PROSPERO registration: CRD42023396192.

Risk Factors for Dislocation following Total Hip Arthroplasty in Developmental Dysplasia of the Hip: A Systematic Review and Meta-Analysis

PURPOSE

This systematic review and meta-analysis aimed to identify risk factors of dislocation after total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH).

METHODS

A systematic literature review was performed on 18th August 2022 using Medline, Embase, Scopus, Web of Science electronic databases, and a manual search. The study was conducted according to the PRISMA guidelines and registered with PROSPERO. Statistical analysis includes assessment of heterogeneity and data synthesis using RevMan 5.4.

RESULTS

Review of five studies including 2865 patients and 116 dislocated hips found that lower body mass index (BMI) (SMD = 0.22, p = 0.04, I2 = 0%), Crowe classification type IV versus I, II, and III (OR = 2.70, p = 0.004, I2 = 51%), higher cup inclination (SMD = 0.39 p = 0.0007, I2 = 0%), femoral head size < 28 mm (OR = 5.07, p = 0.003, I2 = 71%), lateral surgical approach (OR = 1.96, p = 0.02, I2 = 0%), and postoperative infection (OR = 6.26, p < 0.0001, I2 = 0%) were significant risk factors. However, age, gender, cup anteversion, femoral osteotomy, vertical (V-COR) centre of rotation, intraoperative fracture, preoperative and postoperative leg length discrepancy (LLD) and previous hip surgery were not found to be significant risk factors.

CONCLUSION

This study underscores importance of these risk factors in THA planning for DDH patients to reduce dislocation risk. Further research needed to understand mechanisms.

Transverse subtrochanteric shortening osteotomy with double tension-band fixation during THA for Crowe III-IV developmental dysplasia: 12-year outcomes

BACKGROUND

When performing total hip arthroplasty in patients with severe developmental dysplasia, shortening the femur facilitates reduction while also preventing sciatic or crural nerve injury and excessive length of the operated limb. No consensus exists about the optimal type of implant and best internal fixation procedure, two parameters that directly govern the risk of the most common intraoperative and postoperative complications (diaphyseal fractures, dislocation, non-union). To minimise these risks, we developed a technique combining a transverse subtrochanteric shortening osteotomy, a long ovoid-profiled, cementless stem anchored in the metaphysis, and double tension-band wiring for internal fixation. The primary objective of this study was to evaluate the outcomes of this technique with emphasis on (i) complications and femoral implant survival, (ii) clinical outcomes (functional scores and lower-limb length inequality [LLLI]), and time to healing.

HYPOTHESIS

Our technique is associated with low rates of intraoperative and postoperative complications.

MATERIAL AND METHODS

This single-centre retrospective cohort study included patients who underwent THA with a transverse subtrochanteric shortening osteotomy and fixation using double tension-band wiring to treat severe (Crowe III or IV) developmental hip dysplasia. The femoral implant was a long, ovoid, cementless stem fully coated with hydroxyapatite. We collected the intraoperative and postoperative complications, survival, LLLI, functional scores (Harris Hip Score [HHS] and Forgotten Joint Score [FJS]), patient satisfaction, and radiographic outcomes.

RESULTS

The study included 31 hips in 25 patients. Two patients (2/31 hips, 6.5%) were lost to follow-up, leaving 29 hips for the analysis of postoperative outcomes. Mean follow-up was 13.7±4.2 years (range, 5.8-18.3 years). The four intraoperative complications (4/31, 12.9%) consisted fracture of the diaphysis (2/31, 6.5%), fracture of the greater trochanter (1/31, 3.2%), and sciatic nerve injury followed by a full recovery (1/29, 3.4%). The 8 (8/29, 27.5%) postoperative complications consisted of dislocation (2/29, 6.9%), stem subsidence (2/29, 6.9%), and non-union (4/29, 13.8%). Femoral implant survival at last follow-up was 87.1% (95% CI, 76.1-99.7). The mean HHS increased from 39.6±12.0 (range, 14-61) before surgery to 81.7±13.2 (range, 48-100) at last follow-up (p<0.01). The FJS at last follow-up indicated that the joint was forgotten in 14/29 (48.2%) cases and caused only acceptable symptoms in 9/29 (31.0%) of cases. Clinically significant (≥ 1cm) LLLI was present in 8/29 (27.6%) patients postoperatively compared to 19/29 (65.5%) preoperatively. The mean LLLI decreased from 20.8±19.7mm (range, 0-60mm) to 5.0±7.3mm (range, 0-30mm). Mean time to healing was 4.3±2.4 months (range, 2-11 months).

CONCLUSION

Regarding these complex procedures, this technique was associated with low rates of intraoperative fractures and early postoperative complications. However, femoral stem survival was shorter than in earlier studies and the non-union rate was high, despite satisfactory functional and clinical outcomes.

LEVEL OF EVIDENCE IV

How Often Do Patients Presenting With Severe Adolescent Idiopathic Scoliosis Have Underlying Hip Dysplasia?

INTRODUCTION

Adolescent idiopathic scoliosis radiographic screening will often include the hips. The purpose of this study is to evaluate the prevalence of hip dysplasia by lateral center edge angle (LCEA) on scoliosis radiographs in patients presenting with severe range (>45 deg) idiopathic curves.

METHODS

We reviewed 200 consecutive patients (400 hips) with idiopathic scoliosis with major coronal curves ≥45 degrees between October 2009 and October 2022. The presenting scoliosis radiograph PA were reviewed for the following variables: major coronal curve direction, coronal balance, and lateral center edge angles. An LCEA value ≤18 was considered dysplastic. To assess potential measurement variability related to parallax of the scoliosis radiographs, the intermodality intraclass correlation coefficient (ICC) was measured from a subset of 20 hip LCEA values from patients with both scoliosis and pelvis radiographs.

RESULTS

A total of 200 patients [mean age: 13.6 (1.8) years; Female: 79%] were reviewed. The mean major curve (SD) was 58.6 degrees (11.4 deg). Overall 19% (37/200) patients or 11% (43/400) of hips had hip dysplasia. Of the dysplastic hips, 16% (6/43, P <0.001) were bilateral and 57% (21/43, P =0.04) were right sided. There was no association between dysplastic hip laterality and ipsilateral or contralateral coronal balance ( P =0.26) or curve direction ( P =0.49). The interobserver ICC for assessment of LCEA on scoliosis radiographs was 0.85, and the intermodality ICC between pelvic and scoliosis radiographs was 0.78.

CONCLUSION

Hip dysplasia was present in 19% of patients presenting with large major curves, and many of these patients had right sided hip dysplasia. There was no association between hip dysplasia laterality and the patient's major curve direction or coronal balance. There was good intermodality reliability (ICC=0.78) between LCEA values in patients who had both scoliosis and pelvis radiographs, and good inter-rater reliability between raters. Radiographic interpretation of adolescent idiopathic scoliosis should focus not only on the description of the curve and ruling out underlying segmentation anomalies but should also include critical assessment of the hips to exclude co-existing hip dysplasia.

LEVEL OF EVIDENCE

Therapeutic study-level IV.

Long-term outcomes of total hip arthroplasty in patients with developmental dysplasia of the hip: a minimum 21-year follow-up

PURPOSE

Early osteoarthritis (OA) due to developmental dysplasia of the hip (DDH) is a known indication for total hip arthroplasty (THA). Though screening tools and joint-preserving procedures have been established successfully, there still is a relevant number of patients suffering DDH. Due to the lack of long-term outcome studies, we like to close this gap and present the results of a highly specialized center.

METHODS

The study included 126 patients, who were treated in our institution with primary THA for DDH between January 1997 and December 2000. At the time of final follow-up, at a mean of 23 years postoperatively, 110 patients (121 hips) were clinically evaluated using the Harris-Hip Score. In addition, complication and surgical revision rates were assessed. We collected surgery-related data like implant choice and special surgical features such as autologous acetabular reconstruction or femoral osteotomies. Additionally, the severity of preoperative DDH was measured radiographically according to Crowe classification.

RESULTS

There were 91 female (83%) and 19 male (17%) patients with an average age of 51 ± 9.5 years (range 21-65) included. Mean follow-up was 23 ± 1.3 years (21-25), with a minimum of 21 years being necessary for inclusion. Using revision for any indication as primary endpoint, the Kaplan-Meier survivorship was 98.3% at 10 years and 81.8% at final follow-up. The overall revision rate was 18% (22 cases), which were split up as follows: 20 (17%) implant failures (loosened or broken components), one (1%) periprosthetic infection and one (1%) periprosthetic fracture. Regarding complications, we observed nine (7%) dislocations and one case (1%) with severe heterotopic ossification that required surgical excision. The mean Harris-Hip score at latest follow-up was 78 ± 14 points (32-95).

CONCLUSIONS

Though implants and surgical techniques have improved over time, our results suggest THA in patients suffering DDH to be seriously challenging with relatively high overall complications in long-term observation and fair clinical outcome after 21 years postoperatively. There is evidence that prior osteotomy might be associated with a higher revision rate.

Vitamin D status-associated postoperative complications in patients with hip dysplasia after periacetabular osteotomy: A case-control study

OBJECTIVES

This study aimed to clarify the relationship between vitamin D status and complications after periacetabular osteotomy.

METHODS

A total of 46 hips of 39 patients (3 men and 36 women; mean age at surgery, 41.0 years; mean postoperative follow-up duration, 63 months) were reviewed to obtain the following information: patients' serum 25-hydroxyvitamin D [25(OH)D] status, prevalence of postoperative delayed union of osteotomy sites in the greater trochanter (DUGT) and ischiopubic stress fractures (IPSFs), and risk factors.

RESULTS

The mean serum 25(OH)D level was 11.9 ng/ml. DUGT and IPSF were found in four (10.3%) and three (7.7%) patients, respectively. Serum 25(OH)D levels ≤ 11 ng/ml were significantly associated with DUGT in female patients (p = .02). Serum 25(OH)D levels ≤ 9 ng/ml and smoking were significantly associated with IPSF (p = 0.01 and 0.02, respectively). Overall, 21.7% of patients with serum 25(OH)D levels ≤ 11 ng/ml developed at least one complication; no complications occurred when serum 25(OH)D levels were >11 ng/ml.

CONCLUSION

Severe vitamin D deficiency was highly prevalent in relatively young patients. Vitamin D deficiency and smoking were independent risk factors for postoperative complications. Proactive supplementation is advisable to reduce postoperative complications, especially in patients with serum 25(OH)D levels ≤ 11 ng/ml.

Effects of hip brace on coxa valga in nonambulatory children with cerebral palsy: A randomized controlled trial

BACKGROUND

Coxa valga, measured as the neck-shaft angle (NSA) or head-shaft angle (HSA), is regarded as a potential risk factor for hip dislocation in patients with cerebral palsy. We investigated the effects of a novel hip brace on coxa valga.

METHODS

A prospective, multicenter, assessor-blinded, randomized controlled trial was conducted from July 2019 to November 2021. Children with cerebral palsy aged 1 to 10 years with Gross Motor Function Classification System levels IV and V were recruited. The study group wore a hip brace for at least 12 hour a day. A lower strap of the hip brace was designed to prevent coxa valga biomechanically. The effectiveness of the hip brace on coxa valga was assessed by measurement of the NSA and head-shaft angle at enrollment and 6 and 12 months after enrollment.

RESULTS

Sixty-six participants were enrolled, and 33 patients were assigned to each group. Changes in the mean NSA of both sides and the NSA of left side showed significant differences between the 2 groups over 12 months (mean NSA of both sides, -1.12 ± 3.64 in the study group and 1.43 ± 3.75 in the control group, P = .023; NSA of the left side, -1.72 ± 5.38 in the study group and 2.01 ± 5.22 in the control group, P = .008).

CONCLUSIONS

The hip brace was effective in preventing the progression of coxa valga and hip displacement, suggesting that the prevention of coxa valga using hip brace is a contributing factor in prevention of hip displacement.

Identification of A Novel Variant of Filamin A Destroying the Attraction Between Benzene Rings and Sulfhydryl in Developmental Dysplasia of the Hip

Developmental dysplasia of the hip (DDH), characterized by acetabular deformity that manifests from loose ligaments to complete dislocation of the hip, can cause notable pain and dysfunction and lead to hip dislocation, secondary fractures, scoliosis, and osteoarthritis of hip. Variants in FLNA may produce a spectrum of malformations in multiple organs, especially the skeleton. This study aimed to identify the genetic etiologies of DDH patients and provide genetic testing information for further diagnosis and treatment of DDH. We recruited a Chinese woman with DDH and her family members. Whole-exome sequencing was used to identify the patient's genetic etiologies. Protein models were used to analyze the pathogenic mechanism of the identified variants. A novel variant (c.3493T>G, p.C1165G) of FLNA was detected. The structural models of the mutant FLNA protein indicated that the variant would lose its sulfhydryl side chain and destroy the attraction between benzene rings and sulfhydryl. We reported a novel variant (c.3493T>G, p.C1165G) of FLNA in a Chinese woman with DDH. Our research outcome enriches the gene pool for hip dysplasia and emphasizes the pathogenicity of sulfhydryl side chain disruption in FLNA.

Assessing Leg Length Discrepancy Is Necessary Before Arthroplasty in Patients With Unilateral Crowe Type IV Hip Dislocation

BACKGROUND

THA for high-riding developmental dysplasia of the hip (DDH) is challenging in terms of length equalization. Although previous studies suggested preoperative templating on AP pelvic radiographs is insufficient in patients with unilateral high-riding DDH because of hypoplasia of the hemipelvis on the affected side and unequal femoral and tibial length on scanograms, the results were controversial. The EOS™ (EOS™ Imaging) is a biplane X-ray imaging system using slot-scanning technology. Length and alignment measurements have been shown to be accurate. We used the EOS to compare the lower limb length and alignment in patients with unilateral high-riding DDH.

QUESTIONS/PURPOSES

(1) Is there an overall leg length difference in patients with unilateral Crowe Type IV hip dysplasia? (2) In patients with unilateral Crowe Type IV hip dysplasia with an overall leg length difference, is there a consistent pattern of abnormalities in the femur or tibia that account for observed differences? (3) What is the impact of unilateral high-riding Crowe Type IV dysplasia on femoral neck offset and knee coronal alignment?

METHODS

Between March 2018 and April 2021, we treated 61 patients with THA for Crowe Type IV DDH (high-riding dislocation). EOS imaging was performed preoperatively in all patients. Eighteen percent (11 of 61) of the patients were excluded because of involvement of the opposite hip, 3% (two of 61) were excluded for neuromuscular involvement, and 13% (eight of 61) had previous surgery or fracture, leaving 40 patients for analysis in this prospective, cross-sectional study. Each patient's demographic, clinical, and radiographic information was collected with a checklist using charts, Picture Archiving and Communication System, and an EOS database. EOS-related measurements that were related to the proximal femur, limb length, and knee-related angles were recorded for both sides by two examiners. The findings of the two sides were statistically compared.

RESULTS

The overall limb length was not different between the dislocated and nondislocated sides (mean 725 ± 40 mm versus 722 ± 45 mm, mean difference 3 mm [95% CI -3 to 9 mm); p = 0.08). Apparent leg length was shorter on the dislocated side (mean 742 ± 44 mm versus 767 ± 52 mm, mean difference -25 mm [95% CI -32 to 3 mm]; p < 0.001). We observed that a longer tibia on the dislocated side was the only consistent pattern (mean 338 ± 19 mm versus 335 ± 20 mm, mean difference 4 [95% CI 2 to 6 mm]; p = 0.002), but there was no difference between the femur length (mean 346 ± 21 mm versus 343 ± 19 mm, mean difference 3 mm [95% CI -1 to 7]; p = 0.10). The femur of the dislocated side was longer by greater than 5 mm in 40% (16 of 40) of patients and shorter in 20% (eight of 40). The mean femoral neck offset of the involved side was shorter than that of the normal side (mean 28 ± 8 mm versus 39 ± 8 mm, mean difference -11 mm [95% CI -14 to -8 mm]; p < 0.001). There was a higher valgus alignment of the knee on the dislocated side with a decreased lateral distal femoral angle (mean 84° ± 3° versus 89° ± 3°, mean difference - 5° [95% CI -6° to -4°]; p < 0.001) and increased medial proximal tibia angle (mean 89° ± 3° versus 87° ± 3°, mean difference 1° [95% CI 0° to 2°]; p = 0.04).

CONCLUSION

A consistent pattern of anatomic alteration on the contralateral side does not exist in Crowe Type IV hips except for the length of the tibia. All parameters of the limb length could be shorter, equal to, or longer on the dislocated side. Given this unpredictability, AP pelvis radiographs are not sufficient for preoperative planning, and individualized preoperative planning using full-length images of the lower limbs should be performed before arthroplasty in Crowe Type IV hips.

LEVEL OF EVIDENCE

Level I, prognostic study.

Hip reconstruction in children with cerebral palsy: does magnitude of surgery influence complications and outcomes?

Children with cerebral palsy (CP) and neuromuscular hip dysplasia (NMHD) frequently require hip reconstruction including femoral and pelvic osteotomies. Outcomes and complications in CP patients with NMHD who underwent varying degrees of hip reconstruction surgeries were examined. Ninety-nine patients with a diagnosis of CP who underwent surgical management of NMHD over a 15-year period (2005-2020) were reviewed. Three patient cohorts with varying degrees of surgery were analyzed including: (1) unilateral femoral osteotomy with pelvic osteotomy; (2) bilateral femoral osteotomy with unilateral pelvic osteotomy; and (3) simultaneous bilateral femoral osteotomy and bilateral pelvic osteotomy. Data points included operative (OR) time, length of stay (LOS), estimated blood loss (EBL), and transfusion requirement. Complications during the perioperative and postoperative periods were identified and graded by severity. Increased EBL, need for transfusion, OR time, and LOS were observed more frequently in patients undergoing bilateral reconstruction. Complication rates were high for all three cohorts, with 87% of cases in the bilateral pelvic osteotomy cohort experiencing ≥1 complication. However, 90% of these were considered grade I or II and required no or minimal intervention. The average postoperative migration index at final follow-up for treated hips was significantly less in bilateral pelvic osteotomy cases. Patients with CP and bilateral NMHD can be safely managed with bilateral simultaneous comprehensive reconstruction. The data presented in this study can help both surgeons and families anticipate a more accurate postoperative course. Level of evidence: III.

Periacetabular Osteotomy for Symptomatic Acetabular Dysplasia in Patients ≥40 Years Old: Intermediate and Long-Term Outcomes and Predictors of Failure

BACKGROUND

The Bernese periacetabular osteotomy (PAO) is controversial as a treatment for symptomatic acetabular dysplasia in patients ≥40 years of age. We conducted a retrospective study to evaluate the outcomes, measure the survival rate, and identify factors associated with PAO failure in patients ≥40 years of age.

METHODS

We performed a retrospective study of patients ≥40 years of age undergoing PAO. Study eligibility criteria were met by 166 patients (149 women; mean age, 44 ± 3 years), and 145 (87%) were followed for ≥4 years after PAO. We used a Kaplan-Meier curve with right-censoring to calculate survivorship, with "failure" defined as either conversion to or recommendation for total hip arthroplasty or a Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score of ≥10 at the most recent follow-up. We used simple logistic regression models to determine whether any preoperative characteristics were significantly associated with PAO failure.

RESULTS

The median follow-up time was 9.6 years (range, 4.2 to 22.5 years). Sixty-one of 145 hips (42%, 95% confidence interval [CI] = 34% to 51%) experienced PAO failure during follow-up. The median survival time was 15.5 years (95% CI = 13.4 to 22.1 years). The median survival time was longer for hips with no or mild preoperative osteoarthritis: 17.0 years for Tönnis grade 0, 14.6 years for grade 1, and 12.9 years for grade 2. Higher preoperative Tönnis arthritis grades (p = 0.03) and worse WOMAC function scores (p < 0.001) were associated with an increased likelihood of failure.

CONCLUSIONS

PAO is usually effective at improving function and is effective at preserving the hip in patients ≥40 years of age provided that they have good preoperative function and no or mild preoperative osteoarthritis (Tönnis grade 0 or 1). Patients who are ≥40 years old with advanced preoperative osteoarthritis (Tönnis grade 2) and those with poor preoperative dysfunction have a high risk of therapeutic failure after PAO.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Is seizure disorder a risk factor for complications following surgical treatment of hip dysplasia in the pediatric population?

The impact of seizure disorders on pediatric patients who undergo hip dysplasia surgery has yet to be elucidated. This study focused on identifying the effect of seizure disorders on the incidence of complications following surgical management of hip dysplasia. Pediatric patients undergoing surgical treatment for hip dysplasia from 2012 to 2019 were identified in the National Surgical Quality Improvement Program-Pediatric database. Patients were divided into two cohorts: patients with and patients without a seizure disorder. Patient demographics, comorbidities and postoperative outcomes were compared between the two groups. Bivariate and multivariate analyses were performed. Of 10 853 pediatric patients who underwent hip dysplasia surgery, 8117 patients (74.8%) did not have a seizure disorder whereas 2736 (25.2%) had a seizure disorder. Bivariate analyses revealed that compared to patients without a seizure disorder, patients with a seizure disorder were at increased risk of developing surgical site infections, pneumonia, unplanned reintubation, urinary tract infection, postoperative transfusion, sepsis, extended operation time and length of stay and readmission ( P  < 0.05 for all). Following adjustment for patient demographics and comorbidities on multivariate analysis, there were no differences in any postoperative complications between pediatric patients with and without a seizure disorder. There were no differences in 30-day postoperative complications in patients with and without a seizure disorder. Due to potential decreased bone mineral density as an effect of antiepileptic drugs and the risk of femur fracture during surgery for hip dysplasia, pediatric patients with a seizure disorder should be closely monitored as they may be more susceptible to injury. Level of Evidence: III.

Acetabular deficiency in borderline hip dysplasia is underestimated by lateral center edge angle alone

INTRODUCTION

In hip preservation surgery, the term "borderline hip dysplasia" was used when the lateral center edge angle (LCEA), historically described by Wiberg, measured 18-25°. In recent years, several radiographic parameters have been described to assess the antero posterior coverage of the femoral head, for example, the anterior and posterior wall index (AWI and PWI). This allowed an increasingly comprehensive understanding of acetabular morphology and a questioning of the borderline definition.

MATERIAL AND METHODS

A retrospective review of 397 consecutive hips was performed, all treated with triple pelvic osteotomy (TPO) due to symptomatic hip dysplasia. On all preoperative pelvic radiographs with a LCEA of 18-25°, acetabular index (AI), AWI and PWI were measured. With these values, the hips were categorized into laterally, antero-laterally and postero-laterally dysplastic and stratified by gender. Intra- and interobserver correlation of the parameters was analyzed by intraclass correlation coefficient (ICC).

RESULTS

According to LCEA, 192 hips were identified as "borderline dysplastic". Based on AWI and PWI, the categorization resulted in 116 laterally dysplastic (60.4%), 33 antero-laterally (17.2%) and 43 postero-laterally dysplastic hips (22.4%). Gender stratification revealed that male acetabula seemed to be slightly more postero-laterally deficient than female (mean PWI 0.80 vs 0.89; p = 0.017). ICC confirmed highly accurate and reproducible readings of all parameters.

CONCLUSION

The rather high proportion of symptomatic hips labelled borderline dysplastic suggested, that there might be substantial acetabular deficiency not recognizable by LCEA. Comprehensive deformity analysis using LCEA, AI, AWI and PWI showed, that 40% of these hips were deficient either antero-laterally or postero-laterally. Male acetabula were more deficient postero-laterally than female.

[Complication management after periacetabular osteotomy]

BACKGROUND

Hip dysplasia is the most common cause of secondary hip osteoarthritis. The Ganz periacetabular osteotomy (PAO) is a well-established procedure that allows a reliable and reproducible correction of the complex pathology. The promising medium and long-term good treatment results are offset by the potential risk of complications from an invasive pelvic procedure. Considering the mainly young age of the patients, knowledge of the possible complications and the resulting adequate therapy is crucial.

TREATMENT DEVELOPMENT

The continuous development of surgical techniques and increase in overall surgical experience alongside the appreciation of critical surgical steps have led to a substantial reduction of serious complications. In addition, to improve patient outcome, a greater understanding of the associated pathologies that may be related to hip dysplasia is essential.

Mid-term low back pain improvement after total hip arthroplasty in 306 patients with developmental dysplasia of the hip

BACKGROUND

Low back pain (LBP) from hip and spinal disorders has been one of the main reasons for visiting physicians in patients with developmental dysplasia of the hip (DDH). It is essential to identify the LBP improvement among all grades of DDH patients treated with total hip arthroplasty (THA) at 5-year follow-up.

METHODS

The study included 407 hips of 306 patients (38 males, 268 females) who underwent THA between July 2007 and December 2016. There were 65 hips in Crowe I, 61 hips in Crowe II, 69 hips in Crowe III, and 212 hips in Crowe IV. One hundred and fourteen hips received subtrochanteric shortening. Patients included 101 bilateral THA (BTHA) and 205 unilateral THA (UTHA). The evaluation was performed through Back Pain Function Scale (BPFS), Harris hip score, Visual Analogue Scale (VAS), operative data and radiographic examinations.

RESULTS

The BPFS in patients of unilateral Crowe III and IV relieved significantly more (p < 0.05). However, the BPFS in patients with bilateral symmetry DDH hips relieved significantly less than other groups of DDH hips (p < 0.05). Harris in hips of Crowe II improved significantly more (p < 0.05). The VAS in hips of Crowe II and III improved significantly more (p < 0.05). The unilateral THA surgical time, blood loss, blood transfusion, and osteotomy number and length in Crowe IV were significantly more (p < 0.05).

CONCLUSION

THA is reliable to relieve LBP in DDH patients of unilateral Crowe III and IV; however, in patients with unilateral Crowe I, Crowe II, and bilateral DDH hips, the LBP improvements were limited. This should assist shared decision-making between orthopedic surgeons and patients.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

[Hip dysplasia: What influence do age, arthrosis and concomitant diseases have on the treatment result?]

Pelvic osteotomies are an established treatment for symptomatic adult hip dysplasia with a promising long-term outcome. Results depend not only on the achieved acetabular reorientation but also on patient-factors like preoperative joint condition (degree of osteoarthritis and joint congruency) and age. Additionally, the diagnosis and appropriate therapy of impingement-associated hip deformities is essential in order to achieve good mid- and long-term outcomes. The influence of chondrolabral pathology on the outcome of pelvic osteotomies is not yet defined. Symptomatic patients with residual dysplasia after previous pelvic or acetabular osteotomies can benefit from an additional osteotomy, although results can be worse in comparison to prior unoperated joints. Obesity can make surgery more demanding and increases the complication profile of PAO, although it has no influence on the postoperative outcome. Regarding the overall prognosis after an osteotomy, the consideration of combined risk factors is superior to the concentration on individual factors alone.

Closed reduction and plaster immobilization: an alternative solution for patients with developmental dysplasia of the hip who failed Pavlik harness treatment

BACKGROUND

The current study aims to investigate the clinical efficacy of closed reduction and cast immobilization for patients with developmental dysplasia of the hip (DDH) who failed Pavlik harness treatment.

METHODS

Patients with DDH who underwent cast immobilization under general anaesthesia after the failure of the Pavlik harness or Tübingen brace treatment between January 2015 and December 2020 were retrospectively recruited. General information, including Graf classification of initial diagnosis, initial treatment, age of cast immobilization, IHDI classification, AI index, avascular necrosis (AVN), and residual dysplasia, was collected. The incidence of AVN and late acetabular dysplasia (LACD) was also estimated. Moreover, factors related to AVN and LACD were investigated by multiple logistic regression analysis.

RESULTS

Thirty-four patients (47 hips) were finally included in the current study. Of these patients, 31 hips (66.0%) were successfully treated with closed reduction and cast immobilization. Open reduction was successfully performed in 16 hips (34.0%). Till the latest follow-up, LACD and AVN were found in 13 (27.7%) and 10 (21.3%) hips, respectively. In the open reduction group, type III and IV of the IHDI classification and type IV of the Ultrasound Graf classification were significantly higher when compared with the closed reduction group. Multiple logistic regression showed that failure of closed reduction was related to the initial types of the Ultrasound Graf and IHDI classifications.

CONCLUSIONS

Although the success rate of closed reduction after early harness failure in DDH is only 66%, we still advocate closed reduction as a first-line treatment for children who have failed sling treatment. Even if closed reduction fails, open reduction can still achieve acceptable results.

Chronically elevated contact stress exposure correlates with intra-articular cartilage degeneration in patients with concurrent acetabular dysplasia and femoroacetabular impingement

Hip dysplasia is known to lead to premature osteoarthritis. Computational models of joint mechanics have documented elevated contact stresses in dysplastic hips, but elevated stress has not been directly associated with regional cartilage degeneration. The purpose of this study was to determine if a relationship exists between elevated contact stress and intra-articular cartilage damage in patients with symptomatic dysplasia and femoroacetabular impingement. Discrete element analysis was used to compute hip contact stresses during the stance phase of walking gait for 15 patients diagnosed with acetabular dysplasia and femoral head-neck offset deformity. Contact stresses were summed over the duration of the walking gait cycle and then scaled by patient age to obtain a measure of chronic cartilage contact stress exposure. Linear regression analysis was used to evaluate the relationship between contact stress exposure and cartilage damage in each of six acetabular subregions that had been evaluated arthroscopically for cartilage damage at the time of surgical intervention. A significant correlation (R2  = 0.423, p < 0.001) was identified between chondromalacia grade and chronic stress-time exposure above both a 1 MPa damage threshold and a 2 MPa-years accumulated damage threshold. Furthermore, an over-exposure threshold of 15% regional contact area exceeding the 1 and 2 MPa-years threshold values resulted in correct identification of cartilage damage in 83.3% (55/66) of the acetabular subregions loaded during gait. These results suggest corrective surgery to alleviate impingement and reduce chronic contact stress exposures below these damage-inducing thresholds could mitigate further cartilage damage in patients with hip dysplasia.

Acetabular reconstruction with femoral head autograft in primary total hip arthroplasty through a direct anterior approach is a reliable option for patients with secondary osteoarthritis due to developmental dysplasia of the hip

BACKGROUND

Developmental dysplasia is challenging to treat with total hip arthroplasty via the direct anterior approach (DAA). Reconstructing the former anatomy while restoring the acetabular bone stock for future revisions in this young patient collective combined with the known advantages of the DAA would be desirable. The purpose of this study was to analyze the feasibility, radiographic outcome and clinical outcome of primary uncemented total hip arthroplasty with bulk femoral head autograft for acetabular augmentation through a DAA with a minimal follow-up of 12 months.

METHODS

A retrospective, consecutive series from March 2006 to March 2018 of 29 primary total hip arthroplasty with acetabular augmentation with bulk femoral head autograft through a direct anterior approach was identified. All complications, reoperations and failures were analyzed. Radiographic and clinical outcome was measured.

RESULTS

24 patients (29 hips) with a mean age of 43 (18-75) years and a mean follow-up of 35 months (12-137) were included. Surgical indication was secondary osteoarthritis for developmental dysplasia of the hip (Hartofilakidis Grade A (n = 19), B (n = 10)) in all cases. We noted no conversion of the approach, no dislocation and no acetabular loosening. The center of rotation was significantly distalized by a mean of 9 mm (0-23) and significantly medialized by a mean of 18 mm (6-29). The bone graft was fully integrated after 12 months in all cases.

CONCLUSION

Acetabular reconstruction with femoral head autograft in primary THA through a direct anterior approach seems to be a reliable option for the treatment of secondary osteoarthritis in patients with DDH Hartofilakidis grade A and B. Prospective cohort studies with a large sample population and a long-term follow-up are necessary to confirm our findings.

Risk Factors for Avascular Necrosis After Closed Reduction for Developmental Dysplasia of the Hip

BACKGROUND

Avascular necrosis (AVN) is a major complication after closed reduction for developmental dysplasia of the hip. The factors that predispose to AVN remain controversial. The purpose of this study was to analyze the risk factors, especially patient factors, such as age at reduction, grade of dislocation, and ossific nucleus development, related to AVN.

MATERIALS AND METHODS

We retrospectively reviewed children with dysplasia of the hip treated by closed reduction between 1997 and 2006. AVN was evaluated using Salter criteria and Kalamchi and MacEwen classification. Related factors were analyzed.

RESULTS

One hundred and eight children (140 hips) with an average age of 16.6 months at closed reduction (range: 6-24 mo) were included in the study. For an average duration of 10.1 years (range 7-16 y) of follow-up, 44 hips (31.4%) developed AVN. Grade II or higher AVN occurred in 14 hips (10%). The incidence of AVN increased with the grade of dislocation ( P =0.022) and underdevelopment of the ossific nucleus ( P <0.001). Underdevelopment of the ossific nucleus was also found to be positively correlated with the dislocation grade ( P =0.047). The age at the time of reduction, sex, and side were not significant factors. Children who underwent secondary operation were all older than 1 year at reduction.

CONCLUSIONS

High-grade dislocation correlates with the underdevelopment of the ossific nucleus. Patients with these 2 characteristics are predisposed to AVN. As underdevelopment of the ossific nucleus occurred regardless of age, it is not advisable to delay reduction because it does not alter the AVN rate, and instead, it increases the secondary operation rate.

LEVEL OF EVIDENCE

Level IV case series.

Periacetabular vascular anatomy in high-riding dysplastic hips: a CT angiographic study

BACKGROUND

Developmental hip dysplasia (DDH) is shown to have osseous and neural abnormalities but literature is sparse with investigation of vascular structures. Therefore, we aimed to evaluate periacetabular vascular structures.

METHODS

By computerised tomography angiography (CTA), 13 highly dislocated hips of 11 patients' iliac bone to external iliac and obturatory artery and vein proximities were measured and compared with the same measurements of 20 healthy hips of 12 patients. Numbering from superior to inferior, a total of 7 axial images were created on the 2D CTA coronal images with 1 cm apart, the 4th being at the level of acetabular dome.

RESULTS

The mean age of the patients was 53 (18-72) years. Dysplastic hips tended to have curved (53%) and healthy hips tended to have straight iliac arteries (p = 0.037). As compared to healthy hips, external iliac veins were significantly closer to the bone at all levels, but the external iliac arteries were closest at 1st to 4th levels (p < 0.001) in dysplastic hips. The course of the obturatory arteries was similar in both groups (p = 0.147).

CONCLUSIONS

The external iliac artery and vein is in close proximity to the iliac bone which dangers acetabular screw, acetabular reaming or retractor placement in highly dislocated hips. The surgeon should be aware of this proximity in operations of these hips to avoid vascular complications.

Avascular necrosis under different treatment in children with developmental dysplasia of the hip: a network meta-analysis

The objective of this study was to evaluate the incidence of avascular necrosis (AVN) of the femoral head in children less than 3 years of age with developmental dysplasia of the hip (DDH) treated with closed reduction, open reduction alone and open reduction combined with osteotomy. We reviewed clinical trials from the PubMed, EMBASE and Cochrane Library databases (up to November 2020) that were related to closed reduction, open reduction alone and open reduction combined with osteotomy for the treatment of children under 3 years of age with DDH. The screening and quality evaluation of the literature were performed independently by two researchers. In case of disagreement, a third researcher resolved the discourse. Finally, the data were extracted, and the R software and GeMTC program package were used to conduct a network meta-analysis (NMA). The evaluation index was the incidence of AVN. Fourteen articles were included. The NMA showed that in terms of the incidence of AVN, cases treated with open reduction alone were higher than those with closed reduction, and the difference was statistically significant. Open reduction alone had the highest probability (94.4%) of having the highest incidence of AVN, followed by open reduction combined with osteotomy (5.5%) and closed reduction (0.1%). In the treatment of children with DDH who are younger than 3 years old, open reduction alone is most likely to be the treatment with the highest incidence of AVN, followed by open reduction combined with osteotomy. The closed reduction had the smallest probability of AVN.

Rotational abnormalities in dysplastic hips and how to predict acetabular torsion

OBJECTIVES

The aim of this study was to investigate the degree to which conventional radiography can represent the acetabular and femoral rotational alignment profile between dysplastic and borderline-dysplastic hips.

METHODS

A retrospective trial was conducted including 56 borderline-dysplastic and dysplastic hips at a mean age of 28.9 years (range from 18 to 46). Inclusion criteria consisted of symptomatic patients with hip dysplasia undergoing 2-dimensional radiography as well as computed tomography. On radiography, the lateral center edge angle, acetabular hip index, hip lateralization index, acetabular index angle, and the Sharp angle were measured, and the presence of a crossover sign was noted. In computed tomography, the full rotational profile of the lower limb was measured.

RESULTS

Significant correlations were observed in the overall analysis between the anteversion of the acetabulum and the hip lateralization index (mean 0.56, coefficient of regression (CoR) -32.35, p = 0.011) as well as the acetabular index angle with a mean of 11.50 (CoR 0.544, p = 0.018). Similar results were found in the subgroup of dysplastic hips with an acetabular index angle of 13.9 (p = 0.013, CoR 0.74). For the borderline-dysplastic group, no significant correlations between the pelvis radiography and rotational CT were seen.

CONCLUSION

Although the femoral and acetabular torsion cannot be predicted from x-rays, the anteversion of the acetabulum correlates with the acetabular index angle, the hip lateralization index, and eventually the beta angle in dysplastic hips. For borderline-dysplastic hips, such results did not show up, which strongly illustrates the need for computed tomography in these cases.

KEY POINTS

• Much of the current literature focuses on rotational alignment especially with respect to the femur and tibia in healthy patients, although little is known about the acetabular, femoral, and tibial torsion in dysplastic hips. • This is the first study showing significant correlations between the anteversion of the acetabulum and the hip lateralization index as well as the acetabular inclination angle. Also, it is the first study to provide a mechanism for estimation of the torsion of the acetabulum with plain radiography in dysplastic hips. • In borderline-dysplastic hips, no significant correlation was found, which raises the question if a simple x-ray has enough validity to address the acetabular deformity with surgery.

Intraoperative two-stage evaluation of muscle contractures in Crowe type IV hips in total hip arthroplasty (a new surgical technique)

BACKGROUND

It is important to maintain soft-tissue balance and prevent muscle contractures after hip reduction during total hip arthroplasty (THA) in patients with Crowe type IV developmental dysplasia of the hip (DDH). To make such hips functional and durable, the techniques to achieve soft-tissue balance were studied to create an algorithm for intraoperative 2-stage evaluation of muscle contractures, specifying the optimal order for contracture release.

METHODS

Between February 2011 and March 2015, we evaluated 64 patients (75 hips) with DDH for muscle contractures as they underwent THA. Following acetabular implantation, femoral osteotomy was applied of various lengths according to limb-length discrepancy. First, the distal part of the femur was prepared by broaching, and the hip was then reduced. The tensor fascia lata, rectus femoris, sartorius, hamstrings, and adductor muscles were evaluated, and any contractures were released. A trial conjoining of the distal and proximal parts of the femur was made, and the hip was reduced again. Finally, the iliopsoas and abductor muscles were evaluated, and contractures were released.

RESULTS

The mean follow-up duration was 4.6 years. Preoperative and postoperative Harris Hip Scores were 52 and 87, respectively. Limb-length discrepancy was mean 4.2 cm preoperatively, and <1 cm postoperatively. All contractures were released according to our newly developed algorithm.

CONCLUSIONS

It is challenging to pinpoint the main muscle causing contractures, because other muscles acting on the hip joint have similar secondary functions. The method we describe here may provide better and more specific restoration of muscle function in a hypoplastic hemipelvis in DDH.

Prevalence of radiographic hip dysplasia in Japanese population-based study

OBJECTIVES

The purpose of this study was to measure the indices of radiographic developmental dysplasia of the hip (DDH) in a cross-sectional study of an elderly Japanese population.

METHODS

Hip radiographs of 427 informed, voluntary Japanese community-dwelling individuals (279 female and 148 male) aged 50-96 years-old were obtained from Miyagawa village in Japan through a health screening. The hip radiographs were measured by a custom-written, semi-automated MATLAB program. The center edge (CE) angle, acetabular roof obliquity (ARO), acetabular head index (AHI), and minimum joint space width (mJSW) were measured. We examined the associations between gender, side-of-hip, and age group on radiographic DDH and hip osteoarthritis (OA).

RESULTS

The mean CE angle was 31.0°. The mean ARO was 5.8°. The mean AHI was 88.2%. The mean mJSW was 4.0 mm. Of the total population, 29.9% had DDH and 4.0% had hip OA. Of those who had hip OA, 41.2% were secondary OA, and 58.8% were primary OA. The relationship between DDH and OA was not significant.

CONCLUSION

DDH is unlikely to be an important cause of hip OA in the present population-based study.

What happens to the gluteus medius in young and middle-aged patients with hip dysplasia?

BACKGROUND

Much research has focused on quantifying the bony characteristics of patients with developmental dysplasia of the hip (DDH). Far less attention, however, has been paid to muscle abnormalities around the hip such as those in the gluteus medius (GM).

METHODS

We retrospectively examined clinical and imaging data, such as the age of onset and computed tomography (CT) findings, in 108 consecutive hips. Subjects for the control group were selected from our radiology database. Two readers independently evaluated the length (LGM), cross-sectional area (CSA), width (WGM), and thickness (TGM) of the GM and arm of GM (AGM) and angle of the GM activation (AOA) and bony parameters including the acetabulum-head index (AHI), lateral central edge angle (LCEA), acetabular index (AI), femoral offset (FO), and height of the rotation centre of femoral head (HCFH) among all cases using the imaging data.

RESULTS

The patient group included 108 hips. The AGM, LGM, CSA, and TGM were lower in the DDH patients, while AOA was higher. However, there was no significant difference in the WGM between the two groups. Multiple linear regression analysis showed that AGM and AOA were independent factors affecting LCEA. The following regression equation was used: Y(LCEA) = 5.377 * X1 (AGM) - 0.310 * X2 (AOA) - 11.331. The mechanical characteristics of the GM and many bony parameters were significantly correlated (the AGM and AHI, LCEA, AI, FO, but not HCFH; AOA and AHI, LCEA, AI, but not FO or HCFH). The CSA was positively correlated with only HCFH. The rest were not statistical significance linear correlation. The multivariate regression results showed that the age of onset was positively correlated with AGM (r = 0.467). The regression equation used was Y = 9.0 * X (age of onset) - 11.4.

CONCLUSION

We found difference in the morphological and mechanical characteristics of the GM between hips with DDH and hips of normal morphology. Of note, the mechanical characteristics of the GM were influenced by bony parameters in patients with DDH.

Periacetabular Osteotomy and Femoral Head Allograft for Hip Dysplasia and Femoral Head Cyst: A Case Report

CASE

A 34-year-old woman with developmental dysplasia of the hip (DDH) presented with chronic left hip pain related to a femoral head cyst. The patient strongly preferred a joint-preserving option. Periacetabular osteotomy (PAO) has shown reliable options for managing DDH, and femoral head fresh osteochondral allograft (FOCA) can be performed for cysts. We performed these procedures concomitantly for the first time. At 1-year follow-up, the patient had functional, pain-free motion and high satisfaction.

CONCLUSION

PAO and femoral head FOCA can be performed concomitantly with a common, anterior hip approach. They are a viable, joint-preserving option for patients with DDH and osteochondral lesions.

Late Stabilization of Developmental Dysplasia of the Hip Without Treatment: A Case Report

CASE

Approximately three-quarters of neonates with unstable hips will spontaneously stabilize without treatment in the first few weeks of life. This report presents the long-term follow-up of an infant with developmental dysplasia of the hips that stabilized at an older age and without any orthopaedic treatment.

CONCLUSIONS

Factors contributing to the spontaneous stabilization in this case included the patient's self-selected lower extremity position of comfort with hips flexed, abducted, and externally rotated; her delayed walking; and her light body weight.

Hip Dysplasia and Osteogenesis Imperfecta: A Case Report

CASE

A 1-week-old female patient presented to our clinic with bilateral dislocated hips and was subsequently treated in a Pavlik harness. Harness treatment failed requiring a closed reduction and spica cast application. In the Post-Anesthesia Care Unit (PACU), the patient was found to have a right humerus fracture. Six weeks after cast application, the patient was found to have nondisplaced bilateral femur fractures prompting a genetics evaluation. The patient was subsequently found to have osteogenesis imperfecta type 3.

CONCLUSION

Perioperative fractures in pediatric patients should raise suspicion for osteogenesis imperfecta. Early diagnosis can improve the management of hip dysplasia and allow for early bisphosphonate therapy.

Novel 3D printed integral customized acetabular prosthesis for anatomical rotation center restoration in hip arthroplasty for developmental dysplasia of the hip crowe type III: A Case Report

RATIONALE

Exact restoration of the rotation center in total hip arthroplasty (THA) is technically challenging in patients with end-stage osteoarthritis due to developmental dysplasia of the hip (DDH), especially in the Crowe type II and III procedures. The technical difficulty is attributable to the complex acetabular changes. In this study, a novel 3-dimensional (3D) printed integral customized acetabular prosthesis for anatomical rotation restoration in THA for DDH Crowe type III was developed using patient-specific Computer-aided design and additive manufacturing (AM) methods.

PATIENT CONCERNS

A 69-year-old female patient had developed left hip joint pain and restricted movement for 40 years; the symptoms had increased in the past 5 months. Pain, limited motion of the left hip joint, and lower limb length discrepancy were noted during physical examination.

DIAGNOSIS

The patient was diagnosed with left hip end-stage osteoarthritis secondary to DDH (Crowe type III).

INTERVENTION

A 3D printed acetabulum model was manufactured and a simulated operation was performed to improve the accuracy of reconstruction of the rotation center and bone defect. A 3D printed titanium alloy integral customized acetabular prosthesis was designed according to the result of simulated operation. The integral customized prothesis was implanted subsequently via the posterolateral approach. Radiography of the pelvis and Harris score assessment were performed during the perioperative period as well as at the 6- and 12-month follow-up.

OUTCOMES

The 3D printed integral customized acetabular prosthesis matched precisely with the reamed acetabulum. The rotation center was restored and the bone defect was exactly reconstructed. There were no signs of prosthetic loosening at the 12-month follow-up. The Harris score gradually improved during the follow-up period.

LESSONS

Satisfactory results of hip rotation restoration and bone defect reconstruction could be achieved by using 3D printed integral customized acetabular prosthesis, which provides a promising way to reconstruct the acetabulum in patients with DDH anatomically and rapidly for THA.

Bilateral Total Hip Replacement in Dwarfism With a Custom Laser-Printed Trabecular Acetabular Shell

Total hip arthroplasty in cases of dwarfism may be a demanding procedure, as the small-sized joints are difficult to replace with standard prostheses, even more so in the presence of dysplastic hips. The authors report a case of bilateral customized total hip arthroplasty performed in a young patient with proportionated dwarfism with bilateral hip dysplasia. To ensure sufficient stabilization of the cup, roof bone grafting was performed. The custom-made acetabular component was a trabecular acetabular shell manufactured using selective laser melting technology to ensure an optimal porous structure to enhance primary stability and bone ingrowth. Selective laser melting may be a promising alternative technology for manufacturing highly porous customized acetabular components for complex joint reconstruction procedures in which enhanced osseointegration ability is particularly required. [Orthopedics. 2019; 42(5):e477-e479.].

Primary Total Hip Arthroplasty in Severe Dysplastic Hip Osteoarthritis With a Far Proximal Cup Position

BACKGROUND

Developmental hip dysplasia is the most common cause of secondary hip osteoarthritis. Due to severe acetabular bone deficiency, cup positioning in total hip arthroplasty (THA) of dysplastic hips remains a surgical challenge. The aim was to analyze the functional outcome of far proximal cup positions in primary THA.

METHODS

Fifty patients (61 hips) with THA for severe dysplastic osteoarthritis and a far proximal cup position were included. Patients were divided according to the heights of the implanted cups with increasing vertical distance from the interteardrop line (group A: 55-65 mm, group B: 65-75 mm, group C: >75 mm). Functional outcome was assessed at latest follow-up (38 ± 16 months) by Lower Extremity Functional Score, Tegner Activity Score, and Harris Hip Score (HHS). Patients answered a Patient Satisfaction Questionnaire. Leg length discrepancy was estimated radiographically.

RESULTS

The Lower Extremity Functional Score significantly decreased in C (45.3 ± 25) compared to A (66.7 ± 15.3) and B (67.9 ± 9.9). The Tegner Activity Score significantly increased in all subgroups from preoperative to postoperative (2.2 ± 1.3 to 4.1 ± 1.4; P < .05). The mean overall HHS was 89.3 ± 14.7 (A: 89.5 ± 14.3, B: 94.3 ± 6.5, C: 78.3 ± 22.1). The HHS domains of activity of daily life and gait were significantly reduced in C (P < .05). Patients described a high satisfaction level with the surgery. No significant differences were found with regard to preoperative and postoperative leg lengthening (P = .881). Neither dislocations, impingement problems nor neurologic complications were observed.

CONCLUSION

Primary THA without any concomitant surgical interventions with a far proximal cup position offers a safe and effective treatment option in severe dysplastic hip osteoarthritis.

Curved periacetabular osteotomy using intraoperative real-time 3-dimensional computed tomography with a robotic C-arm system: A case report

RATIONALE

Curved periacetabular osteotomy (CPO) is a procedure with excellent surgical outcome that has been proposed for patients with development dysplasia of the hip (DDH). However, the surgical outcomes depend on the surgeon's experience and proficiency.

PATIENT CONCERNS

A 38-year-old female indicated she was experiencing left hip pain while walking.

DIAGNOSES

The patient was diagnosed with early-stage hip osteoarthritis due to DDH.

INTERVENTIONS

The patient underwent CPO while a 3-dimensional flat-panel C-arm (Artis zeego; Sciemens Healthcare, Forchheim, Germany) was used to confirm the real-time 3-dimensional computed tomography (CT) images during surgery. It was possible to confirm the accurate osteotomy curve using CT images twice during surgery: at the time of the ischial osteotomy and the quadrilateral surface osteotomy.

OUTCOMES

An ideal C-shaped osteotomy line was created as shown on the postoperative CT images. In addition, neither posterior column fracture nor intra-articular osteotomy was confirmed.

LESSONS

The CPO using Artis zeego resulted is a satisfactory outcome, and this is the 1st report in the world to discuss the benefits of Artis zeego in pelvic osteotomy.

Spinal dysraphism and dislocated hip: Beware of anomalous sciatic nerve through Ilium, a case report

RATIONALE

The sciatic nerve runs a predictable course combining L4-S3 nerve roots through the true pelvis and under the greater sciatic notch. There are reports of bony protuberances from the sacrum and ilium in cases of spinal dysraphism; however advanced imaging, treatment, or outcomes are not described. There are no cases with associated fibular hemimelia in the current literature.

PATIENT CONCERNS

This is a 4-year-old girl with tethered cord, acetabular dysplasia with hip subluxation, congenital short femur, anterior cruciate ligament (ACL) deficiency, and fibular hemimelia with her sciatic nerve coursing through the ilium.

DIAGNOSIS

Aberrant course of the sciatic nerve through the ilium in the setting of spinal dysraphism.

OUTCOMES

The hip subluxation was treated with a femoral varus derotation osteotomy and Salter osteotomy with transposition of the sciatic nerve into the greater sciatic notch resulting in a stable hip with no sciatic nerve symptoms at last follow-up.

LESSONS

The combination of spinal dysraphism with acetabular dysplasia should be a warning for anomalous sciatic nerveanatomy, possibly through the ilium. Preoperative imaging (MRI, CT scan) may be obtained and carefully reviewed for the course of the sciatic nerve prior to pelvic or femoral osteotomy. Decompressing the sciatic nerve from the aberrant foramen may be considered as part of the procedure.

A retrospective study on the relationship between altered native acetabular angle and vertical implant malpositioning

PURPOSE

Acetabular cup positioning in extreme angles of vertical position affects both stability and long-term survivorship of total hip arthroplasty. The purpose of this study is to determine whether native Sharp's angle is associated with an increased abduction angle of the acetabular component.

METHODS

Consecutive patients who underwent primary total hip replacement between February 2012 and August 2015 were included. Vertical positioning of acetabular implant in the antero-posterior post-operative radiographs were measured. The proportion of implants positioned outside the safe zone (40° ± 10°) was calculated and through a multivariate analysis, Sharp's angle and other factors possibly associated with cup malpositioning were evaluated.

RESULTS

Five hundred twenty-eight hip arthroplasties were analyzed. Prevalence of cup malpositioning was 7.6% and 25 patients had an altered native acetabular angle. An altered pre-operative Sharp's angle was associated with a higher risk of vertical malpositioning of the acetabular component (OR 2.51 IC 95%: 1.17-5.39) (p = 0.02). Body mass index, surgeon's volume, size of the implant, gender, pre-operative diagnose and age, were not associated with the position of the cup.

CONCLUSIONS

The alteration of the Sharp's angle as an indicator of hip dysplasia in native hips increases the odds of acetabular cup malpositioning. Other factors explored did not correlate with the position of the acetabular prosthesis. Systematic assessment of Sharp's angle should be included in the pre-operative planning of primary hip arthroplasty.

Rapid Prototyping 3D Model in Treatment of Pediatric Hip Dysplasia: A Case Report

BACKGROUND

Rapid prototyping is an emerging technology that integrates common medical imaging with specialized production mechanisms to create detailed anatomic replicas. 3D-printed models of musculoskeletal anatomy have already proven useful in orthopedics and their applications continue to expand.

CASE DESCRIPTION

We present the case of a 10 year-old female with Down syndrome and left acetabular dysplasia and chronic hip instability who underwent periacetabular osteotomy. A rapid prototyping 3D model was created to better understand the anatomy, counsel the family about the problem and the surgical procedure, as well as guide surgical technique. The intricate detail and size match of the model with the patient's anatomy offered unparalleled, hands-on experience with the patient's anatomy pre-operatively and improved surgical precision.

CONCLUSIONS

Our experience with rapid prototyping confirmed its ability to enhance orthopedic care by improving the surgeon's ability to understand complex anatomy. Additionally, we report a new application utilizing intraoperative fluoroscopic comparison of the model and patient to ensure surgical precision and minimize the risk of complications. This technique could be used in other challenging cases. The increasing availability of rapid prototyping welcomes further use in all areas of orthopedics.

Alumina Delta-on-Highly Crosslinked-Remelted Polyethylene Bearing in Cementless Total Hip Arthroplasty in Patients Younger than 50 Years

BACKGROUND

The purpose of this retrospective study was to determine the clinical and radiographic results, prevalence of polyethylene wear and osteolysis, and fracture of alumina delta ceramic femoral head or highly crosslinked, remelted polyethylene (HXLPE) liner associated with the use of alumina delta ceramic femoral head-on-HXLPE bearing in cementless total hip arthroplasty in patients younger than 50 years.

METHODS

We reviewed the cases of 119 patients (130 hips) who underwent a cementless total hip arthroplasty using alumina delta ceramic-on-HXLPE bearing when they were 50 years or younger at the time of surgery. The most common diagnoses were osteonecrosis (51%) and osteoarthritis secondary to developmental dysplastic hip (39%). Osteolysis and polyethylene wear rates were evaluated with use of radiography and computed tomography. In addition, prevalence of fracture of alumina delta ceramic head and polyethylene line was documented. The mean follow-up was 8.3 years (range, 7-9 years).

RESULTS

The mean Harris hip score, Western Ontario and McMaster Universities Osteoarthritis Index score, University of California, Los Angeles activity score were 94 points, 14 points, and 8.1 points, respectively, at the final follow-up. No patient had thigh pain. All acetabular components and all but one femoral components were well fixed. The mean annual penetration rate of femoral head was 0.022 ± 0.003 mm/year. No hip had osteolysis or ceramic head or HXLPE liner fracture.

CONCLUSION

Our average 8.3-year results with the use of alumina delta ceramic-on-HXLPE bearing in the patients younger than 50 years suggest that cementless acetabular and femoral components provide a high survival rate without evidence of osteolysis or ceramic head or AXLPE liner fracture.