Evaluation of Acetabular Development Following Open Reduction of Developmental Dysplasia of Hip in Children After Walking Age

Background and purposeThe growth and development of the acetabulum in children with developmental dysplasia of hip (DDH) depends upon the extent of concentric reduction. Children in walking age often need open reduction with or without additional osteotomies to obtain congruous, stable reduction. The purpose of this study was to evaluate acetabular development in late diagnosed DDH treated by open reduction with or without femoral osteotomy.MethodsThis is a retrospective study of 29 children (40 hips) with idiopathic DDH, previously untreated managed by open reduction with or without femoral osteotomy. We analyzed preoperative and yearly postoperative radiographs up to 6 years of age for acetabular development by measuring acetabular index. Acetabular remodeling was assessed with a graphical plot of serial mean acetabular index. Those with AI < 30° at outcome measure point of 6 years of patient age were considered to have satisfactory acetabular remodeling.ResultsMean age of surgery was 26.8 months. Open reduction alone was done in 14 hips and open reduction with concurrent femoral osteotomy done in 26 hips. The mean acetabular index pre operatively was 36.6° ± 5.9° which reduced to 29.7° ± 6° at 1-year follow-up and to 26.6° ± 5.9° at 2-year follow-up. 28 out of 40 hips were available for evaluation at outcome measure point of 6 years of age, which showed satisfactory remodeling in 24 hips with mean AI of 22.7° ± 5.7°. Maximum acetabular development was seen at 2 years post-surgery and better remodeling was seen in children operated at less than 2 years of age. 5 hips had changes of avascular necrosis of femoral head. There was no incidence of redislocation/subluxation at latest follow-up.ConclusionOpen reduction in late-diagnosed developmental dysplasia of hip has potential for favourable acetabular development. Femoral osteotomy when required along with open reduction may suffice to address acetabular dysplasia found in the initial years of management of DDH.     

Residual Acetabular Dysplasia in the Reduced Hip

BackgroundResidual acetabular dysplasia occurs in up to a third of patients treated successfully for developmental dysplasia of the hip (DDH) and has been found to be a significant risk factor for early hip osteoarthritis (OA).DiscussionAge at the time of initial reduction and the initial severity of DDH have been linked to residual acetabular dysplasia. An anteroposterior pelvic radiograph is the main diagnostic modality, but MRI also provides valuable information, particularly in equivocal cases. The literature supports intervening when significant residual acetabular dysplasia persists at 4–5 years of age, and common surgical indications include acetabular index (AI) > 25°–30°, lateral center–edge angle (LCEA) < 8°–10°, and a broken Shenton’s line on radiographs; and a cartilaginous acetabular angle (CAI) > 18°, cartilaginous center–edge angle (CCE) < 13°, and/or the presence of high-signal intensity areas on MRI. Surgical options include redirectional pelvic osteotomies and reshaping acetabuloplasties, which provide comparable radiographic and clinical results.ConclusionRAD is common after treatment of DDH and requires regular follow-up for diagnosis and appropriate management to decrease the long-term risk of OA. Long-term outcomes of patients treated with pelvic osteotomies are generally favorable, and the risk of OA can be decreased, although the risk of total hip replacement in the long-term remains.     

Eccentric Rotational Acetabular Osteotomy Using Computed Navigation Guidance for Developmental Dysplasia of the Hip,Sacroiliac Fusion,and Femoroacetabular Impingement Owing to Acetabular Retroversion: A Case Report

BackgroundDevelopmental dysplasia of the hip (DDH) is the main factor that causes secondary osteoarthritis of the hip (hip OA). Acetabular retroversion results in pincer‐type femoroacetabular impingement (FAI), and this is also known to cause secondary hip OA. However, few cases of DDH with acetabular retroversion have been reported, and there is no definite opinion on the optimal treatment. We report a rare case of DDH and FAI owing to acetabular retroversion and dysostosis of the sacroiliac joint that was treated with eccentric acetabular rotational osteotomy (ERAO) using navigation guidance.Case PresentationA 27‐year‐old woman presented with DDH and acetabular retroversion with FAI and dysostosis of the sacroiliac joint on the contralateral side. We performed ERAO using computed navigation guidance and improved the coverage and retroversion of the acetabulum. The acetabular anteversion angle improved from 1° retroversion to 9° anteversion after surgery, the center edge angle improved from 18° to 43°, and the acetabular head index improved from 69% to 93%. The cam lesion of the femur was resected. The Harris Hip Score improved from 55.7 to 100 points at the final examination 2 years after surgery.ConclusionsIn this rare case of DDH and FAI, ERAO using computed navigation guidance accurately improved the coverage and retroversion of the acetabulum.     

A Comparative Study of Clinical and Radiological Outcomes of Open Reduction Using the Anterior and Medial Approaches for the Management of Developmental Dysplasia of the Hip

BackgroundThe literature is scanty on reports directly comparing the outcomes of anterior open reduction (AOR) and medial open reduction (MOR) in the management of developmental dysplasia of the hip (DDH).Purpose of the StudyTo compare clinical and radiographic outcomes of surgical treatment using either AOR or MOR in children with DDH aged < 24 months and to evaluate the procedure-inherent risks of avascular necrosis of the femoral head (AVN) and need for further corrective surgery (FCS).Methods61 children who underwent surgical treatment for DDH were categorized into two groups: AOR (31 hips of 28 patients) and MOR (39 hips of 33 patients). The mean age was 17 ± 5.85 (range 7–24) months in group AOR and 13 ± 5.31 (range 6–24) months in group MOR. The mean follow-up was 118 ± 41.2 (range 24–192) months and 132 ± 36.7 (range 24–209) months in group AOR and MOR. At the final follow-up, mid- to long-term clinical and radiographic outcomes were assessed. FCS was recorded.ResultsRegarding McKay’s clinical criteria, both groups exhibited similar results (p = 0.761). No significant differences were observed between the groups in both the center–edge–angle (p = 0.112) and the Severin score (p = 0.275). The AVN rate was 32% in the AOR group and 20% in the MOR group (p = 0.264). The FCS rate was 22% in the AOR group and 12% in the MOR group (p = 0.464).ConclusionsThis study showed similar clinical and radiological outcomes with AOR and MOR with no significant relation to AVN and FCS.Level of EvidenceLevel III.     

Change of Pelvic Sagittal Tilt after Total Hip Arthroplasty in Patients with Bilateral Crowe Type IV Developmental Dysplasia of the Hip

ObjectiveTo explore and analyze the change of pelvic sagittal tilt (PST) after total hip arthroplasty (THA) in patients with bilateral Crowe type IV developmental dysplasia of the hip (DDH).MethodsThe study retrospectively evaluated 43 patients with bilateral Crowe type IV DDH undergoing THA from January 2008 to June 2019 who were followed up for 12 months postoperatively. Four parameters, including the ratio between the height and width of the obturator foramina(H/W ratio), the vertical distance between the upper edge of the symphysis and the middle of the sacrococcygeal joint (SSc distance), the vertical distance between the upper edge of the symphysis and the line connecting bilateral hip centers (SC distance) and the vertical distance between the upper edge of the symphysis and the line connecting the bilateral lower ends of the sacroiliac joints (SSi distance), which could indirectly reflect the change of PST, were observed and measured by radiographs. The change of each parameter before operation, immediately after operation, and in 3, 6 and 12 months postoperatively was compared and analyzed.ResultsCompared with the value before operation, the H/W ratio immediately after operation and in 3, 6 and 12 months postoperatively were 0.61 ± 0.12 (t = 0.893, P = 0.377), 0.61 ± 0.11 (t = 1.622, P = 0.112), 0.67 ± 0.10 (t = 5.995, P < 0.001) and 0.76 ± 0.12 (t = −9.313, P < 0.001), respectively, and the SSc, SC and SSi distance in 6 months postoperatively were 30.12 ± 7.06 mm (t = 3.506, P = 0.002), 42.8 ± 7.7 mm (t = 5.843, P < 0.001), 129.3 ± 12.6 mm (t = 5.888, P < 0.001), respectively, and in 12 months postoperatively were 27.24 ± 7.68 mm (t = 6.510, P < 0.001), 36.1 ± 9.1 mm (t = 9.230, P < 0.001), 118.9 ± 14.9 mm (t = 8.940, P < 0.001), respectively. The radiographs obtained in 6 and 12 months postoperatively demonstrated a significantly increased H/W ratio and decreased SSc, SC and SSi distance. At the last follow‐up, the clinical evaluations significantly improved in all patients and there were no revisions.ConclusionThe significant change of pelvic sagittal posterior tilt in patients with bilateral Crowe type IV DDH might be a significant phenomenon after THA, which could occur in 6 months postoperatively.     

Learning Curve of Total Hip Arthroplasty in Direct Anterior Approach without Requiring Corrective Osteotomy for Hip Dysplasia

ObjectiveTo explore the learning curve of total hip arthroplasty in direct anterior approach (DA‐THA) without requiring corrective osteotomy for patients with unilateral developmental dysplasia of the hip (DDH) through the evaluation of clinical and radiographic results.MethodFrom December 2015 to January 2021, we retrospectively evaluated a surgeon''s first 100 patients with unilateral hip dysplasia (Crowe I‐III) who underwent DA‐THA. All procedures were performed by a fellowship‐trained joint surgeon. Cementless hemispheric porous‐coated acetabular cups and tapered cementless stems were used in all hips. The radiographic data, including leg length, the height of the center of rotation, femoral head offset, the cup anteversion and inclination angle, were measured. The cumulative sum analysis (CUSUM) and risk‐adjusted cumulative sum analysis (RA‐CUSUM) were used to determine the learning curve of DA‐THA for each patient''s operation time. By analyzing the operation time, complication rate, postoperative length of hospitalization and creatine kinase (before surgery and the third day after surgery), estimated blood loss, Harris score, radiographic data were compared between the different stages of the learning curve.ResultsThe mean follow‐up time was 35.45 ± 16.82 months. The CUSUM method obtained the maximum turning point of the curve at 43 cases, which divided the learning curve into Learning Period and Mastery Period. The CUSUM learning curve was best modeled as a cubic curve with the equation: CUSUM (min) = 0.001x ³ − 0.495x² + 33.60x − 10.00, which had a higher R ² value of 0.967. The pre‐operative data, creatine kinase, estimated blood loss and postoperative Harris scores of the two stages were not statistically significant (P > 0.05). The mean operation time was 118 min in the Learning Period and 87 min in the Mastery Period. Statistically significant differences were detected in the operation time (P < 0.001), postoperative length of hospitalization(P = 0.024), and postoperative leg length discrepancy (P = 0.012) between the two stages. The overall complication rates were 27.9% in the Learning Period and 12.3% in the Mastery Period (p = 0.049). The overall outliers of radiographic data were 34 cases in the Learning Period and 31 cases in the Mastery Period (79.07% vs 54.39%, P = 0.010).ConclusionsThe DA‐THA is a valuable alternative to achieve satisfactory clinical results for mild‐to‐moderate DDH patients. Furthermore, accurate analysis of the learning curve of DA‐THA for hip dysplasia by the CUSUM method showed that the surgeons need to finish about 43 cases to master the technique.     

Borderline Developmental Dysplasia of the Hip: A Risk Factor Predicting the Development and Poor Prognosis after Core Decompression for Idiopathic Osteonecrosis of the Femoral Head

ObjectiveIt is unclear whether idiopathic osteonecrosis of the femoral head (ONFH) is associated with borderline developmental dysplasia of the hip (BDDH). This study aimed to compare the incidence of BDDH between patients with idiopathic ONFH and matched control subjects and determine the influence of BDDH on poor prognosis after core decompression (CD).MethodsWe retrospectively examined 78 consecutive patients (111 hips) with idiopathic ONFH undergoing CD and 1:2 matched with 156 control subjects (222 hips). The anteroposterior pelvic radiographs were used to measure the acetabular anatomical parameters and divide included subjects into BDDH or non‐BDDH group. The incidence of BDDH and acetabular anatomical parameters were compared between patients with idiopathic ONFH and matched controls. Clinical outcomes, such as Harris Hip Score (HHS), progression of collapse, and conversion to total hip arthroplasty (THA), were compared between patients with BDDH and without BDDH in the idiopathic ONFH group, with a mean follow‐up of 72.1 ± 36.6 months.ResultsPatients with idiopathic ONFH had a significantly higher incidence of BDDH than matched controls (29.7% vs 12.2%, p < 0.001). Less acetabular coverage was also found in patients with idiopathic ONFH than in matched controls as demonstrated by lower CEA (28.5° ± 4.7° vs 33.1° ± 5.7°, p < 0.001), AHI (82.4 ± 5.0 vs 86.3 ± 5.4, p < 0.001), ADR (299.6 ± 28.4 vs 318.8 ± 31.3, p < 0.001), and a higher sharp angle (40.0° ± 3.4° vs 37.4° ± 3.7°, p < 0.001). In patients with idiopathic ONFH, the BDDH group had a significantly lower mean HHS at the last follow‐up (83.5 ± 17.4 vs 91.6 ± 9.7, p = 0.015) with a different score distribution (p = 0.004), and a lower 5‐year survival rate with both clinical failure (66.7%, 95% CI 52.4%–84.9% vs 83.7%, 95% CI 75.2%–93.1%; p = 0.028) and conversion to THA (74.6%, 95% CI 60.7%–91.6% vs 92.1%, 95% CI 85.6%–99.0%; p = 0.008) as the endpoints than the non‐BDDH group.ConclusionThe incidence of BDDH was significantly higher in patients with idiopathic ONFH than matched controls, and idiopathic ONFH patients who underwent CD with BDDH had lower mean HHS as well as 5‐year survival rate than those without BDDH. Therefore, BDDH should be considered a risk factor predicting the development of idiopathic ONFH as well as poor prognosis after CD.     

Restoring Rotation Center in Total Hip Arthroplasty for Developmental Dysplasia of the Hip with the Assistance of Three Dimensional Printing Technology: A Pilot Study

ObjectiveTo develop a new method to restore hip rotation center exactly and rapidly in total hip arthroplasty (THA) with the assistance of three dimensional (3D) printing technology and evaluate its clinical and radiological outcomes.MethodsFrom March 2014 to July 2018, a total of 17 patients (five hips of four men and 16 hips of 13 women) with end‐stage osteoarthritis secondary to developmental dysplasia of the hip who underwent THA were analyzed and followed up retrospectively. The average age is 58.00 ± 8.12 years (range from 45 to 71 years). Simulated operations were performed on 3D printed hip models for preoperative planning. The morphology of Harris fossa and acetabular notches were recognized and restored to locate the acetabular center. The size of bone defect was measured by the bone wax method. The agreement on the size of acetabular cup and bone defect between simulated operations and actual operations were analyzed. Harris Hip Score (HHS) was used to evaluate the recovery of hip joint function. The vertical distance and horizontal distance of the rotation center on the pelvis plain radiograph were measured, which were used to assess the efficacy of restoring hip rotation center and acetabular cup migration.ResultsThe mean sizes of bone defect in simulated operations and THA were 4.58 ± 2.47 cm² and 4.55 ± 2.57 cm² respectively. There was no significant difference statistically between the sizes of bone defect in simulated operations and the actual sizes of bone defect in THA (t = 0.03, P = 0.97). The sizes of the acetabular cup of simulated operations on 3D print models showed a high rate of coincidence with the actual sizes in the operations (ICC = 0.93). All 17 patients were available for clinical and radiological follow‐up. The average follow‐up time was 18.35 ± 6.86 months (range, 12–36 months. The average HHS of the patients was improved from (38.33 ± 6.07) preoperatively to the last follow‐up (88.61 ± 3.44) postoperatively. The mean vertical and horizontal distances of hip rotation center on the pelvic radiographs were restored to 15.12 ± 1.25 mm and 32.49 ± 2.83 mm respectively. No case presented dislocation or radiological signs of loosening until last follow‐up.ConclusionsThe application of 3D printing technology facilitates orthopedists to recognize the morphology of Harris fossa and acetabular notches, locate the acetabular center and restore the hip rotation center rapidly and accurately.     

Clinical and Radiological Outcomes of Revision Total Hip Arthroplasty for Patients with Prior Hartofilakidis Type C Hip Dysplasia

ObjectiveTo investigate the clinical and radiological results of revision total hip arthroplasty (THA) for patients with previously diagnosed Hartofilakidis type C hip dysplasia, which is technically challenging and lacks literature.MethodsWe enrolled 20 patients with previously diagnosed Hartofilakidis type C hip dysplasia who underwent revision THA between November 2008 and July 2015 at our hospital. Patients were followed up for an average of 87 months. Data pertaining to the Harris hip score (HHS), modified Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), general satisfaction, and the level of satisfaction related to 16 hip functions or issues experienced after revision THA were collected. The vertical and horizontal center of rotation (COR) of the hips were measured bilaterally based on preoperative and postoperative anteroposterior radiographs. Categorical variables were analyzed by the chi‐square test. Continuous variables were analyzed using the student''s t test or non‐parametric Wilcoxon Rank Sum test.ResultsThere were significant postoperative improvements in the HHS (47.4 ± 31.6 vs 70.1 ± 39.0), modified WOMAC (48.5 ± 27.9 vs 75.7 ± 36.8), and the vertical (45.7 ± 33.7 mm vs 21.6 ± 21.8 mm) and horizontal (41.8 ± 17.0 mm vs 31.4 ± 14.7 mm) offset of the COR after revision THA (P < 0.05). Fifteen (75.0%) patients were satisfied with the procedure. The satisfaction rate for each of the 16 items ranged from 45% to 100%. The top three dissatisfactory items were squatting, getting into/out of cars, and leg‐length discrepancy. Postoperatively, dissatisfied patients had a significantly higher visual analogue scale pain score and lower WOMAC pain, HHS pain, WOMAC total, and HHS total scores, a lower satisfaction rate for pain relief, and a higher vertical COR.ConclusionThere is a high rate (25%) of dissatisfaction with the outcome after revision THA for patients with prior Hartofilakidis type C hip dysplasia. The most likely reasons for dissatisfaction were inadequate pain relief and a higher vertical COR measured on radiography.     

Selective ultrasound screening is inadequate to identify patients who present with symptomatic adult acetabular dysplasia

Purpose

One goal of neonatal screening for developmental dysplasia of the hip (DDH) is the prevention of late surgery. However, the majority of patients with acetabular dysplasia at skeletal maturity are not diagnosed with DDH during infancy. Selective ultrasound screening may identify patients with neonatal hip instability, but may be ineffective for the prevention of dysplasia presenting in adulthood. The purpose of this study is to identify the prevalence of risk factors for DDH that would have warranted selective ultrasound screening in patients with symptomatic acetabular dysplasia after skeletal maturity.

Methods

A prospective hip specialty center registry was used to identify 68 consecutive skeletally mature patients undergoing corrective osteotomy for symptomatic acetabular dysplasia. Risk factors for DDH evaluated in all patients included sex, family history of hip osteoarthritis or DDH, breech, method of delivery, previous hip treatments, and birth order. Radiographs [lateral center edge angle (CEA), anterior CEA, Tönnis grade, and Tönnis angle] were measured preoperatively.

Results

Sixty-seven females and one male were identified. No patients were previously diagnosed with DDH or received treatment for their hips. The majority of patients (85.3 %) did not meet selective ultrasound screening guidelines following a stable neonatal hip exam and, therefore, would not have been screened in a selective screening program. Of the findings outside of screening guidelines, 98.5 % were females, 52.9 % were first born, and 36.8 % had a family history of hip osteoarthritis.

Conclusions

The majority (85.3 %) of patients with symptomatic acetabular dysplasia at skeletal maturity would not have met current recommendations for selective ultrasound screening in the USA had they been born today.     

Prevalence of trochlear dysplasia in infants evaluated for developmental dysplasia of the hip

PurposeThe purpose of this study was to define the incidence of trochlear dysplasia in an infant cohort being screened for developmental dysplasia of the hip (DDH).MethodsNewborns screened for DDH that were evaluated with ultrasound for the presence of trochlear dysplasia were retrospectively reviewed. The sulcus angle and trochlear depth were measured. Based on previous work, trochlear dysplasia was defined as a sulcus angle of > 159°. Our newborn cohort was then analyzed to identify potential risk factors for trochlear dysplasia.ResultsA total of 383 knees in 196 infants were studied. In total, 52% were referred for breech intrauterine positioning and 21% were ultimately diagnosed with DDH and had treatment initiated with a Pavlik harness. Of the entire cohort, 8% of knees were deemed to have trochlear dysplasia. Breech patients were found to have a flatter sulcus angle than those that were not breech (149.5° (sd 7.2°) versus 147.9° (sd 7.5°); p = 0.028). Similarly, a shallower trochlear depth was identified in breech patients versus non-breech patients (1.6 mm (sd 0.4) versus 1.8 mm (sd 0.4); p = 0.019). Those with trochlear dysplasia (as defined by sulcus angle > 159°) did show a smaller alpha angle (i.e. more dysplastic hip) as compared with those without trochlear dysplasia (59.2° (sd 10.2°) versus 65.9° (sd 7.5°); p < 0.001). Hips with DDH were 2.4-times more likely to have knees with trochlear dysplasia (95% confidence interval 1.1 to 5.3).ConclusionUltrasound screening of newborn knees reveals that trochlear dysplasia is relatively common in breech babies with DDH.Level of EvidenceIII     

Arthroscopic Treatment of Labral Tears in Patients with Borderline Developmental Dysplasia of the Hip: A Retrospective Study with Mean 5.8 Years Follow‐Up

ObjectiveTo retrospectively assess the mid‐term clinical and radiological results of hip arthroscopic treatment of labral tears in patients with borderline developmental dysplasia of the hip (BDDH).MethodsFrom January 2010 and December 2019, data were retrospectively reviewed for all patients who underwent arthroscopic surgery of the hip for the treatment of intra‐articular abnormalities. Only the Patients who had borderline developmental dysplasia (BDDH) were included. All operations were performed by two senior surgeons, the arthroscopic treatment including labral repair, labral debridement, minimal acetabuloplasty, femoroplasty and capsular closure. The evaluation consisted of pain evaluation (visual analog scale [VAS]), the modified Harris hip score (MHHS), range of motion, the radiological evaluation of plain film and MRI analysis of the hip joint. The plain film evaluation included anteroposterior views of the pelvis to assess lateral center‐edge angle (LCEA) and acetabular inclination (AI), frog‐leg lateral views of the hip to assess α angle.ResultsThere were 34 patients (36 hips) ultimately enrolled in this study. The follow‐up duration of the patients were minimal 2 years (average, 69.2 months) postoperatively. The patient group included seven men and 27 women, the mean age at the time of surgery was 30.9 years. The mean BMI was 22.3 kg/m². From the pre‐operative status to the final follow‐up visit, mean mHHS score increased from 64.5 to 92.7, mean VAS score decreased from 6.8 to 1.3. All scores exhibited statistically significant differences (P < 0.001). The mean LCEA decreased from 22.9° to 22.7°, the mean AI decreased from 7.7° to 7.6°. Which all showed no significant differences compared with the final follow‐up to the pre‐operative status (P > 0.05). However, the mean α angle was significantly decreased from 48.3° to 40.1° (P < 0.001). We encountered no significant complications such as infection, deep venous thrombosis, fluid extravasation, or permanent nerve injury. One patient (2.94%) underwent revision periacetabular osteotomies (PAO) because of subluxation of the hip joint with permanent pain after 6 months failed conservative treatment.ConclusionArthroscopic treatment of labral tears in patients with BDDH may provide safe and durable favorable results at midterm follow‐up. The best outcome could be expected in patients with labral repair and closure of the capsule with strict patient selection criteria.     

CT Based Analysis of Acetabular Morphology in Northern Indian Population: A Retrospective Study

PurposeThe acetabular morphology has shown to differ among different regions of the world. Multiplanar evaluation by computed tomography (CT) scan is the key to assess acetabular depth, version, and inclination at the same time which have been rarely explored before in the Indian population. We present an anthropometric study of the native acetabulum by CT based coronal, sagittal, and axial parameters in the Northern Indian population.MethodsThe acetabular anteversion (AA), acetabular angle of sharp (AAS), sagittal acetabular angle (SAA), lateral center edge angle (LCEA), acetabular depth (AD), acetabular horizontal offset (AHO), extrusion index (EI) and acetabular depth ratio (ADR) was measured in CT scans of 122 patients (244 hips) without any bony pathologies. LCEA < 20°, ADR < 250, AD < 9 mm, AAS > 43°, and EI ≥ 25% were taken as criteria for dysplastic acetabulum.ResultsThere were 62 males and 60 females included in the study with a mean age of 63.8 ± 17.2 years (21–98 years). In this study, females were having significantly lower ADR (p = 0.002) and higher EI (p = 0.01) than males. The prevalence of dysplasia was 3.2% according to LCEA and 1.6% while combining all of the criteria.ConclusionThere are prominent differences in acetabular depth in the Indian population compared with the population of Western countries or other parts of Asia. Females were shown to have shallower acetabulum than males. The comparative analysis of radiographic parameters obtained from our study with the data available on different country-based studies can help better understanding the acetabular morphology of Indian as well as the worldwide population.Level of StudyRetrospective cross-sectional study.     

Point-of-Care Ultrasound Reduces Visit Time and Cost of Care for Infants with Developmental Dysplasia of the Hip

BackgroundHealthcare institutions and policymakers are searching for system-wide approaches to reduce costs while maintaining quality and improving patient outcomes. In most healthcare systems infants referred for the detecting or treating developmental dysplasia of the hip (DDH) are sent to a radiology department for sonographic evaluation. The total duration of visit and cost of visit are essential variables in any healthcare setting and affect both efficiency and “the bottom line”. By having the treating clinician perform point-of-care ultrasound (POCUS) for the detection and follow-up of patients with DDH, we hypothesize that there would be a significant reduction in the time spent on the visit and the cost incurred without compromising quality or patient satisfaction. To our knowledge, no prior study has examined the effect of incorporating POCUS on the duration and cost of the visit in patients with DDH.PurposeTo determine if there was a difference in the duration of the visit for patients with DDH when POCUS was performed compared to when traditional “formal” sonography was performed. To determine if there was a difference in the cost of the visit for patients with DDH when POCUS was performed compared to when traditional “formal” sonography was performed.MethodsData for visits to a specialized outpatient office were collected over two years at a single-specialty orthopedic hospital, comparing the duration and cost of the visit between patient encounters for infants who had “formal” sonograms performed in the radiology suite to infants who underwent POCUS of the hip. In all, we included 532 patient encounters, 326 patients had POCUS performed, and 206 had a “formal” ultrasonographic evaluation performed. Of these, 140 were new evaluations and 392 were follow-up evaluations for treatment. Of the 140 new patients, 80 were in the POCUS group, and 60 were in the “formal” US group. Of the 392 follow-ups, 246 were in the POCUS group, and 146 were in the “formal” US group.ResultsThe mean duration of the encounter for the POCUS group was 42 min (range 16–75 min), and for the “formal” US group, it was 92 min (range 36–163 min). This difference was statistically significant (p = 0.002). The mean cost of the encounter for the POCUS group was $121.13, and for the “formal” US group, it was $339.38. This difference was statistically significant (p = 0.002).ConclusionUltimately, our study demonstrated a statistically significant reduction in the duration and cost of a patient encounter for infants with DDH when they undergo POCUS rather than “formal” sonographic evaluation.     

Analysis of Factors Affecting Early Functional Recovery of Bernese Periacetabular Osteotomy

ObjectivesTo explore factors affecting the efficacy of Bernese periacetabular osteotomy for the treatment of hip dysplasia.MethodsA retrospective study was conducted on 44 patients with hip dysplasia who underwent Bernese periacetabular osteotomy with a modified Smith‐Peterson approach between January 2017 and November 2019. Among them, 40 were women and four were men. The average age was 31.2 ± 9.4. Preoperative and postoperative imaging parameters were measured. The acetabular top tilt angle, lateral central edge angle, acetabular abduction angle, femoral head extrusion index, sphericity index of femoral head, Shenton line, Tonnis grade of osteoarthritis, joint congruency, p/a ratio, acetabular anteversion angle, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale scores, and modified Harris hip score (MHHS) were observed. MHHS were divided into three clinically relevant categories: poor (<70 points), good (70–85 points), and excellent (86–91 points). Patient demographic data, as well as preoperative and postoperative radiographic parameters, were subjected to univariate logistic regression analysis. Multiple regression analysis was used to determine factors influencing postoperative MHHS.ResultsThe follow‐up time was 1.0–3.9 years after surgery, with an average of 1.6 years. By the last follow‐up, MHHS increased from 70 points before surgery to 91 points after surgery (P < 0.001), WOMAC pain score decreased from 4 points before surgery to 0 points after surgery (P < 0.001). WOMAC functional score decreased (Preoperative: 18.0 [4.0]; Postoperative: 4.0 [0], P = 0.004). Six patients had sensory disturbance of the lateral femoral cutaneous nerve, four of which recovered completely during follow‐up. No other complications related to surgical approach, osteotomy, acetabular displacement, acetabular fixation, and postoperative stage were found. There was no significant vascular, nerve, or visceral injuries in any of the patients. On multiple regression analysis, the probability of the postoperative modified Harris hip score of a hip joint with a preoperative lateral center edge angle ≥4.5° being classified as excellent was six times that of angles <4.5° (Exp[β]: 6.249, 95% CI: 1.03–37.85, P = 0.046). Regression analysis of other factors found no significant correlation with postoperative functional scores.ConclusionOverall functional scores post‐PAO significantly improved, and pain symptoms were significantly reduced. Patients with a preoperative lateral center edge angle ≥4.5° had better joint function after surgery.     

Mid‐Term Outcomes of Cemented Stem and Subtrochanteric Shortening Derotational Osteotomy in Total Hip Arthroplasty for Crowe IV Developmental Dysplasia

ObjectivePerforming subtrochanteric osteotomy with cemented components in patients with Crowe IV developmental dysplasia of the hip (DDH) is technically challenging and not widely reported. This study aimed to evaluate the mid‐term outcomes of cemented stem total hip arthroplasty (THA) with subtrochanteric femoral shortening and transverse derotational osteotomy in patients with Crowe IV DDH.MethodsData collected from patients with Crowe IV DDH who underwent cemented stem THA with subtrochanteric femoral shortening and transverse derotational osteotomy between 2010 and 2018 were retrospectively evaluated. The cemented Lubinus SP II femoral component and the cementless CombiCup acetabular component were used together in all cases. These data, including Harris hip scores, limb length discrepancy (LLD), severity of limp, Trendelenburg test, bone union, length of the resected femur, limb lengthening, level of the osteotomy site, and length bridging the osteotomy site, as well as complications, were analyzed. A paired Student t‐test was used to analyze continuous variables, categorical data were compared using Fisher''s exact probability test, and correlation analysis was performed using Spearman''s rank correlation coefficient.ResultsAmong 14 included patients (10 females and four males), the mean age was 60.4 years (range, 47–73). The mean follow‐up period was 49.1 months, and no patient was lost to follow‐up. The mean Harris hip score improved from 40.7 to 87.7. The mean LLD decreased from 52 to 12.7 mm. The mean length of the excised femoral segment was 38.4 mm, and the mean length of limb lengthening was 27.1 mm. The mean distance between the osteotomy site and the lesser trochanter was 21.1 mm after surgery. The mean length of the femoral stem bridging the osteotomy site was 97.6 mm. Finally, the mean osteotomy union time was 10.6 months. No statistically significant correlation was found between the osteotomy union time and these factors. No neurological deficits were noted. Delayed union was observed in one patient, and postoperative dislocation was observed in two patients. Cement leakage into the osteotomy gap was observed in one patient, however, no revisions were required, and no signs of loosening or migration were observed.ConclusionsCemented stem THA combined with subtrochanteric femoral shortening and transverse derotational osteotomy is safe and effective in treating patients with Crowe IV DDH. Rather than leading to nonunion, cement leakage may negatively affect bone healing.     

There is No Link Between Birth Weight and Developmental Dysplasia of the Hip

AimsDevelopmental Dysplasia of the Hip (DDH) has been linked to high birth weight and packaging disorders, though the evidence is limited. This has implications on screening strategies. The aim of this study was to establish whether birth weight was truly associated with the incidence of DDH.Patients and MethodsThis cohort study analysed the birth weights of all babies born at our institution over a 24 month period, between 01/01/2017 and 01/01/2019. Babies with DDH and those without DDH were compared. Babies were excluded if born before 38 weeks, had incomplete data or were a non-singleton pregnancy. Sub-analysis was performed for DDH severity (dysplastic versus subluxed/dislocated hips), breech presentation, gestational age, gender and ethnicity. Statistical analysis was performed using SPSS.ResultsThere were 10,113 babies born at our institution during the selected timeframe, of which 884 were excluded for prematurity, 336 for being non-singleton and 19 for incomplete data. This left 8874 for analysis, of which 95 babies had confirmed DDH. Both the Non-DDH and DDH data sets had normal distribution (Shapiro-Wilkes, p = 0.308 and 0.629, respectively), with mean birth weights of 3477.7 g with DDH and 3492.8 g without DDH. No difference in birth weight was found (Independent T test, p = 0.789). Females had a lower birth weight than males (3293.1 g versus 3416.6 g (p < 0.001)) yet have a higher incidence of DDH (ratio 6:1 in this dataset). No significant difference was found between birth weights of females with and without DDH (p = 0.068), nor between males with and without DDH (p = 0.513). There were no significant differences in birth weights even when only displaced hips were analysed (p = 0.543), nor according to breech presentation (p = 0.8). Longer gestation babies weighed more (p < 0.00001), yet showed no increase in DDH incidence (p = 0.64).ConclusionThis study discredits the belief that DDH may be related to higher birth weight, thus casting doubt on the link to DDH being a packaging problem in utero. This, therefore, allows future research to prioritise the investigation of alternative aetiologies.     

Three-Dimensional Evaluation of Innominate Bone Rotation in Female Patients with Developmental Dysplasia of the Hip

BackgroundPatients with developmental dysplasia of the hip (DDH) are known to have abnormal pelvic morphologies; however, rotation of innominate bone features remains unclear. Thus, we investigated innominate bone rotation in patients with DDH by measuring the associated angles and distances using three-dimensional (3D) computed tomography.MethodsWe defined four straight lines in pelvic 3D models: from the anterior superior iliac spine to the posterior superior iliac spine, from the anterior inferior iliac spine to the posterior inferior iliac spine, from the pubic tubercle to the ischial spine, and from the pubic tubercle to the ischial tuberosity. Similarly, we measured the angles formed by these lines using the vertical axis of the anterior pelvic plane on the horizontal plane and the horizontal axis on the sagittal plane. Additionally, we measured the distances between the femoral head centers and the acetabular centers in the coronal plane.ResultsThe difference in internal rotation angle between the superior and inferior parts of the iliac bone was significantly lower, by approximately 1.7°, in the DDH group than in the control group (p = 0.007); the difference between the inferior and superior parts of the ischiopubic bone was significantly higher, by approximately 1.5°, in the DDH group (p < 0.001). In the sagittal plane, the sum of the superior aspect of the iliac bone and the inferior aspect of the ischium was significantly lower in the DDH group (p = 0.001) than in the control group. The distances between the femoral heads and the acetabula were significantly greater in the DDH group than in the control group (p = 0.03, p < 0.01, respectively).ConclusionsPatients with DDH had a more internally rotated ilium and ischiopubic bone than normal individuals; however, it should be emphasized that internal rotation was reduced near the acetabulum, and the acetabulum was shifted laterally. Similarly, it was shown that patients with DDH had different rotations of the ilium and ischiopubic bone in the sagittal plane.     

Usefulness of a Simple Preoperative Planning Technique using Plain X‐rays for Direct Anterior Approach for Total Hip Arthroplasty

ObjectiveTo examine the accuracy, reliability, and reproducibility of a simple preoperative planning technique using plain X‐rays.MethodsA retrospective analysis of 96 consecutive cases of primary direct anterior approach (DAA)‐total hip arthroplasty (THA) from July 2015 to December 2018 was performed. The 96 patients included 24 males and 72 females, with an average age of 70 years. The standard AP pelvis radiographs with the patients'' hips extended and internally rotated were obtained pre‐ and postoperatively. The preoperative planning was also completed on the standardized AP pelvic radiographs. The prearranged cup positioning was radiologically measured intraoperatively using fluoroscopy. The correct leg length was assessed intraoperatively, which was compared with the preoperative planning. The component positioning was measured by three independent researchers. Two of the researchers completed the measurements three times, and intra‐observer and inter‐observer reliability were calculated. All patients received at least 6 months follow‐up (6 months–4 years).ResultsIn all cases, the median leg length discrepancy (LLD) was 4.4 mm (range 1.6–15.9 mm), and 84 patients had an LLD smaller than 10 mm, of which 58 patients had an LLD of less than 5 mm. None of the patients had a critical LLD of 2 cm or larger. The multivariable logistic regression for LLD (safe range: yes/no) with the co‐variables including gender, ASA classification, type of cup, the surgeon''s experience level, and the presence of a total hip arthroplasty (THA) on the contralateral side did not present statistical significance. The median angle of the inclination of the acetabular component (IA) was 42.3° (range: 28.7°–52.2°). Ninety‐one patients were within the defined safe range. The hit ratio for the cup to be within the safe zone was significantly higher for the Pinnacle cups than that for the Continuum cups (P < 0.05). However, there was no significant difference in gender, ASA classification, the surgeon''s experience level, and the presence of a total hip arthroplasty (THA) on the contralateral side. The median of its anteversion (AA) was 20.6° (range: 10.6°–40.1°). Only 41 patients were within the defined safe range. None of the co‐variables presented a statistical significance affecting the AA of the cup positioning. Meanwhile, the average fluoroscopy time for the cup positioning (n = 86, missing data in 10 cases) was 4 seconds (range: 1–74), with most of the patients (97.9%) having a fluoroscopy time of fewer than 20 seconds.ConclusionsThe combination of correct preoperative planning and standardized intraoperative measurements can reestablish right leg length and assure the correct cup positioning.     

Reconstruction of Paprosky Type III Acetabular Defects by Three‐Dimensional Printed Porous Augment: Techniques and Clinical Outcomes of 18 Consecutive Cases

ObjectiveTo introduce the surgical technique of reconstruction of Paprosky type III acetabular defects by 3D printed porous augments.MethodsFirst, CT scans of pelvis were obtained to establish the 3D reconstruction model of 3D printed porous augment. Then, a nylon pelvis model was printed to simulate operation with the surgeons. At this time, the augment was designed and modified according to the surgeon''s suggestions and the 3D printing principles. Eighteen patients with Paprosky type III acetabular defects receiving reconstructive surgery by 3D printed porous augments were included in current study. Their data, including general information, intra‐operative findings, imaging results, functional scores, and complications were retrospectively analyzed.ResultsThe mean follow‐up time lasted 33.3 ± 2.0 (24–56) months. The average limb‐length discrepancy (LLD) was 31.7 ± 4.2 (3–59) mm preoperatively, 7.7 ± 1.4 (1–21) mm postoperatively (P < 0.0001), and 7.5 ± 1.2 (0–18) mm at the latest follow‐up. The mean vertical position of hip center of rotation (HCOR) from the interteardrop line changed from preoperative 50.7 ± 3.9 (23.3–75.3) mm to postoperative 22.9 ± 1.9 (10.1–40.3) mm (P < 0.0001), with the latest follow‐up revealing an HCOR of 22.3 ± 1.7 (11.0–40.5) mm. Follow‐up study showed that no hip had radiolucencies and radiological loosening of the acetabular components and augment. The average Harris hip score (HHS) improved from 40.3 ± 4.5 (10.5–71) before operation to 88.4 ± 1.9 (75–97) at the last follow‐up (P < 0.0001). Moreover, follow‐up exhibited that no periprosthetic joint infection, hip dislocation, fracture, and re‐revision occurred.ConclusionSurgical treatment of Paprosky type III acetabular defect with 3D printed porous augment was simple, achieved good match between porous augment and the defect bone surface and the acetabular component, ideally restored LLD and HCOR after operation, significantly improved HHS and attained good early clinical outcomes. It is a promising personalized solution for patients with severe acetabular bone defect.