Challenges in Total Hip Arthroplasty in the Setting of Developmental Dysplasia of the Hip

Decrease in Global Offset Leads to Complaints of Worsening of Valgus Knee Deformity After Total Hip Arthroplasty in Patients With Crowe Type IV Developmental Dysplasia of the Hip

BACKGROUND

Conflicting evidence exists regarding the impact of total hip arthroplasty (THA) on valgus knee deformities in patients with developmental dysplasia of the hip (DDH). The aim of this retrospective study was to identify the factors potentially contributing to the worsening of valgus knee deformities in DDH patients after THA.

METHODS

This retrospective case-control study included 51 patients (69 hips) with Crowe type IV DDH who underwent primary THA between January 2018 and January 2020. The anatomic lateral distal femoral angle (aLDFA), mechanical lateral distal femoral angle (mLDFA), anatomic medial proximal tibial angle (MPTA), hip-knee-ankle (HKA) angle, anatomic tibiofemoral angle (TFA), joint line convergence angle (JLCA), tibial joint line angle (TJLA), femoral offset (FO), acetabular offset (AO), global offset (GO), and extent of leg lengthening were measured before and after THA. The case group comprised patients who complained that their valgus knee deformity worsened after THA, and the control group comprised those who did not. Hip-level data were compared using generalized linear mixed effects models for proportions/rates and linear mixed models for means.

RESULTS

The case group has 19 hips, and the control group has 50 hips. Both groups showed improvement in the HKA after THA (p < 0.05), but the case group presented with a smaller HKA (177.4 ± 2.4 vs. 175.2 ± 2.7, p < 0.001) and greater AO (5.8 ± 1.0 vs. 5.0 ± 1.0, p = 0.011) and GO (7.9 ± 0.7 vs. 7.0 ± 1.1, p = 0.003) values before THA. After THA, GO decreased in both groups, and the TJLA increased in the case group (0.6 ± 2.6 to 2.3 ± 3.5, p = 0.011).

CONCLUSIONS

THA improved the HKA in DDH patients. However, a decrease in GO could lead to an increase in the TJLA, suggesting pseudoprogression of the valgus knee deformity and therefore lead to complaints of worsening of valgus knee deformities. GO restoration during surgery may reduce the impact on the TJLA.

Total Hip Arthroplasty in Challenging Settings: Acetabular Fractures, Adolescents, Conversions, and Developmental Dysplasia of the Hip

Total hip arthroplasty (THA) is one of the most common and successful procedures for the treatment of end-stage hip arthritis. However, in certain complex scenarios, THA can present important and unique challenges, specifically following acetabular fractures in adolescent patients, following failed fixation of proximal femoral fractures, and in developmental dysplasia of the hip (DDH). As these cases involve distorted anatomy, poor bone quality, retained hardware, and previous surgeries, detailed planning, specialized instrumentation and implants, and novel surgical techniques are required. This narrative review examines the challenges, surgical considerations, outcomes, and complications in complex THA management.

Impact of Prosthetic Angle Variations in Combined Anteversion Technique on Surgical Failure Rates in Developmental Dysplasia of the Hip: A 12-Year Follow-Up Study

OBJECTIVES

The combined anteversion technique was introduced to guide prosthesis orientation in patients with developmental dysplasia of the hip and has achieved favorable short-term results in a previously published series. However, excessive variations in implant orientation may increase the risk of accelerated polyethylene wear and lead to revision THA. This study aimed to report whether the variation in implant orientation caused by the combined anteversion technique would result in an increased surgical failure rate and the mid- to long-term clinical outcome in total hip arthroplasty for patients with hip dysplasia.

MATERIALS AND METHODS

This retrospective study reviewed patients with hip dysplasia who underwent total hip arthroplasty with the combined anteversion technique between 2007 and 2012 at our center. The surgical protocol prioritized the combined anteversion principle, requiring maintenance of the combined anteversion within the 25°-50° range while permitting physiological variation in individual femoral or acetabular component positioning. In total, 55 patients (80 hips) were included, with an average follow-up period of 12.7 years (range, 11 to 16). Ceramic fragmentation, periprosthetic radiolucencies, and osteolysis around the cup and stem were evaluated based on the immediate postoperative pelvic anteroposterior radiographs and the last follow-up. Femoral, acetabular, and combined anteversions pre-and postoperatively were measured using CT-based models. The Harris hip score at the latest follow-up was used for comparison with the score before surgery.

RESULTS

The average Harris hip score increased from 28.3 ± 10.1 preoperatively to 91.2 ± 6.7 (p < 0.01) at the last follow-up. The mean femoral, acetabular, and combined anteversions were 25.6° ± 11.1° and 23.7° ± 10.6°, 23.2° ± 7.4° and 19.8° ± 8.3°, and 48.7° ± 12.9° and 43.1° ± 6.8° preoperatively and postoperatively, respectively. By the last follow-up, one patient developed periprosthetic osteolysis 11 years after primary surgery without obvious periprosthetic loosening and migration of the femoral head rotation center. Two patients experienced prosthesis dislocation, one of whom received a revision 4 years after primary surgery, and the other underwent manual reduction under anesthesia 8 years after primary surgery. Two patients underwent revision and internal fixation due to prosthesis loosening caused by a periprosthetic fracture 10 years and 12 years after primary surgery.

CONCLUSION

The combined anteversion technique in total hip arthroplasty for patients with hip dysplasia yielded reliable mid-to-long-term results. This technique's changes in prosthesis angle did not significantly increase the surgical failure rate.

Can customised total hip arthroplasty without femoral shortening osteotomy improve functional outcome and long-term stem survivorship in developmental dysplasia of the hip?

AIMS

Total hip arthroplasty (THA) combined with a shortening osteotomy of the femur has proved to be an effective treatment for patients with developmental dysplasia of the hip (DDH). Advances in surgical technique and implant design have led to the introduction of customised THA, without the inconvenience of femoral shortening osteotomy, as an alternative option.The purpose of this retrospective study was to determine if customised THA without femoral shortening osteotomy improves the functional outcome and long-term survivorship in total hip arthroplasty for DDH.

METHODS

We carried out a retrospective analysis of 77 hips in 62 patients with DDH of all Crowe types who had been treated by customised THA without shortening osteotomy and who had a minimum of 20 years follow-up. Clinical evaluation was undertaken using the Harris Hip Score (HHS) at 6 weeks postoperatively and at final follow-up. Kaplan-Meier survivorship analysis was carried out with femoral revision due to aseptic loosening as the endpoint.

RESULTS

The average HHS score at the 6 weeks postoperative assessment (86 ± 13) showed a significant improvement from the preoperative assessment (49 ± 22 points) as did the final follow-up examination (82 ± 12). The mean postoperative leg-length discrepancy was 7 ± 11 mm (-20-80 mm). 5 transient (6%) nerve palsies (1 sciatic and 4 femoral) were identified. The stem was revised in 12 hips (16%), 9(12%) for aseptic loosening at 4, 16, 70, 96, 165, 176, 177, 191 and 235 months, 2 (3%) for fracture and 1 (1%) for late infection.The Kaplan-Meier survivorship analysis at 20-year follow-up was 88% (95% confidence interval [0.81-0.96]). 7 patients (9 hips) were lost to follow-up (12%). 10 patients (11 hips) died during the study period (14%) but according to their general physician, none had undergone revision hip surgery.

CONCLUSIONS

Customised THA with 3-dimensional planning and a custom-made femoral stem may improve functional outcomes and long-term survivorship after THA for DDH.

Total Hip Arthroplasty in Children: A Dutch Arthroplasty Register Study with Data from 283 Hips

BACKGROUND

Total hip arthroplasty (THA) is rarely performed in pediatric patients and can be challenging in children because of smaller-sized joints, pathomorphological changes around the hip, residual growth, and higher physical demands. Literature on THA outcomes in this unique population is scarce. We aimed to describe characteristics of pediatric patients who underwent THA, 5- and 10-year implant survival, risk factors for revision, and results of patient-reported outcome measures (PROMs) in a large national cohort.

METHODS

Primary THAs (from 2007 through 2022) in pediatric patients (11 to 18 years of age) for non-oncological indications were extracted from the Dutch Arthroplasty Register (LROI). Implant survival was assessed using Kaplan-Meier survival analyses. Functional, quality-of-life, and pain-related PROM scores were described preoperatively and at 3 and 12 months postoperatively and compared using paired t tests.

RESULTS

We included 283 THAs (161 [57%] in female patients) performed in 253 patients. The mean age at surgery (and standard deviation) was 16 ± 1.6 years. The most common indications were osteonecrosis (90 [32%] of the THA procedures), dysplasia (82 [29%]), and osteoarthritis (54 [19%]). The median follow-up was 7 years (range, 2 to 16 years). Fourteen (6% of 234) THAs were revised. The 5- and 10-year cumulative survival rates were 95% (95% confidence interval [CI], 91% to 97%) and 91% (95% CI, 84% to 95%), respectively. There was an insufficient number of events to allow for statistical analyses of potential risk factors for revision. All PROMs had improved significantly at 12 months postoperatively versus preoperatively (p < 0.001).

CONCLUSIONS

This study, the largest to date on THA in children (≤18 years of age), showed good short- and mid-term THA survival, approaching that among adults. Combined with the positive PROM results, THA appears to be an effective and satisfactory intervention in cases of debilitating pediatric hip disease. Further studies should focus on long-term survival and risk factors for implant failure.

LEVEL OF EVIDENCE

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

Retrospective Review of Outcomes of Total Hip Arthroplasty in Developmental Dysplasia of the Hip in Adults

BACKGROUND

Developmental dysplasia of the hip (DDH) is a major cause of hip arthritis in young adults. Total hip arthroplasty (THA) is an effective treatment for DDH, but few studies have examined mid- (5 to 10 years) to long-term (> 10 years) outcomes. This study reports the long-term survivorship, clinical, and radiographic outcomes of THA in DDH patients.

METHODS

A total of 255 patients were included from our retrospective review of THAs from January 2004 to January 2022. Among these cases, 214 (83.9%) were women; the mean age at the time of surgery was 46 years (range, 18 to 87), and the mean follow-up was 8.3 (range, 0.05 to 21.1) years. Kaplan-Meier survivorship analysis was conducted with failure defined as revision surgery for any reason.

RESULTS

Kaplan-Meier survivorship for patients who underwent THA to treat DDH due to all-cause failure was 93.4% (95% confidence interval (CI): 90.3 to 96.5) at 5 years, 92.5% (95% CI: 89.0 to 95.6) at 10 years, and 90.9% (95% CI: 86.2 to 94.0) at 15 years. The overall rate of revision of the index surgery was 18 of 255 (7.1%). These complications included pain (seven), dislocation (four), aseptic loosening of the cup (three), periprosthetic fracture (two), complete foot drop (one), and infection (one). Kaplan-Meier all-cause survivorship for Hartofilakidis A, B, and C was also conducted and showed no significant differences. The mean femoral offset improved from a preoperative value of 12.2 cm (SD 1.4) to a postoperative value of 11.7 cm (SD 1.1) (P < 0.001). The rate of femoral nerve palsy was 0.78%.

CONCLUSIONS

Our study suggests THA for DDH is a viable treatment, providing excellent mid-term to long-term survivorship, clinical, and radiographic outcomes with a low complication rate. Future research should evaluate patient-reported outcomes and long-term follow-up in larger cohorts.

Application and exploration of total hip arthroplasty for developmental dysplasia of the hip assisted by full-process robotics

OBJECTIVE

This study aimed to explore whether total hip arthroplasty (THA) aided by full-process robotics was effective in patients undergoing developmental dysplasia of the hip (DDH).

METHODS

Totally 112 patients were enrolled and classified into robotic-assisted group (n = 56) and the conventional group (n = 56). In addition, retrospective analysis was used for comparing the difference in therapeutic efficacy.

RESULTS

A total of 112 patients received THA, and were followed up for (12.78 ± 0.76) months on average, with no occurrence of associated complications. For patients in robot-assisted group, their abduction and anteversion angles of acetabular cup placement were in the safe zone, while those in 8 patients of the conventional group were outside the safe zone. Compared to the conventional group, the robot-assisted group had higher postoperative Harris Hip Score and FJS, whereas lower VAS score.

CONCLUSION

Robot-assisted THA is advantageous in terms of both intraoperative precision and postoperative effect on the treatment of patients with DDH.

Computed tomography-based navigation versus accelerometer-based portable navigation in total hip arthroplasty for dysplastic hip osteoarthritis

PURPOSE

Accurate cup placement is challenging in total hip arthroplasty (THA) for dysplastic hip osteoarthritis (DHOA) because of the complex morphology of the acetabulum. Studies have reported good accuracy for total hip arthroplasty (THA) using computed tomography-based navigation (CTN); however, in recent years, portable navigation (PN) has become more widely applied because of its low cost and ease of use. This study aimed to compare the accuracy of portable navigation with that of CT-based navigation.

METHODS

A total of 114 patients underwent THA for DHOA via the standard posterior approach in the lateral decubitus position using the CTN (CTN-THA group) or PN (PN-THA group) system. After propensity score matching, 32 patients were included in each group. The accuracy of cup inclination, anteversion, cup placement position, and operative time were compared between the groups.

RESULTS

There was no difference in accuracy error between the CTN-THA (inclination 2.8 ± 2.0° and anteversion 3.4 ± 2.1°) and PN-THA groups (inclination 2.5 ± 1.8° and anteversion 2.6 ± 2.2°). The CTN-THA group (inclination 2.2 ± 2.0° and anteversion 2.1 ± 1.6°) achieved better navigation error compared to the PN-THA group (inclination 2.6 ± 2.2° and anteversion 3.8 ± 3.3°). The error of cup placement position in the anteroposterior direction was significantly larger in the PN-THA group (4.27 ± 3.02 mm) than in the CTN-THA group (2.13 ± 2.17 mm). The operative time was significantly longer in the CTN-THA group (115 ± 41 min) than in the PN-THA group (87 ± 19 min).

CONCLUSIONS

CTN-THA exhibited better accuracy than PN-THA for both cup placement angles and positions. CTN-THA tended to increase the operative time compared to PN-THA.

Preoperative digital design in artificial total hip arthroplasty for patients with Crowe type III and IV developmental dysplasia of the hip: A case series

Successful complete artificial total hip arthroplasty for patients with Crowe type III or IV developmental dysplasia of the hip is challenging in clinical practice. This study aimed to explore the accuracy and effectiveness of preoperative digital design for patients with Crowe type III or IV developmental dysplasia of the hip. This case series study included patients with osteoarthritis secondary to developmental dysplasia of the hip who did not respond to conservative treatment and subsequently required total hip arthroplasty in Tianjin Third Central Hospital between January 2018 and February 2020. A total of 20 patients (5 males and 15 females) were enrolled, of whom 12 presented with Crowe type III and 8 with Crowe type IV developmental dysplasia of the hip. Total hip arthroplasty for each patient was successful. The implanted acetabular cups were one size (2 mm) smaller than the preoperatively designed size in four patients, and the implanted femoral stem prosthesis was one size (1 mm) larger than the preoperatively designed size in four patients with type IV DDH. The Harris scores differed significantly between preoperative and postoperative measurements (58.6 vs. 94.4; P = 0.016). No infection or joint dislocation was observed. Preoperative digital modeling may be used to predict the size of prosthesis required and location for implantation in patients undergoing total hip arthroplasty.

Mid- to Long-Term Outcomes and Complications of Total Hip Arthroplasty in Patients Who Have Crowe IV Developmental Dysplasia of the Hip: A Systematic Review and Meta-Analysis

BACKGROUND

Severe forms of developmental dysplasia of the hip (DDH) in adulthood often lead to total hip arthroplasty (THA). This study aimed to evaluate the mid-term to long-term outcomes of THA in Crowe type IV DDH cases, which represent a technically challenging and complex patient group.

METHODS

PubMed, EMBASE, Web of Science, and Scopus were searched for observational studies and case series with over 100 months of mean follow-up on adult patients who had Crowe type IV DDH treated with THA. A total of 3,710 records were initially identified, leading to the inclusion of 24 studies in the final analysis. These studies were subjected to quality assessment using the National Institutes of Health Quality Assessment tool. Various outcomes including revision rates, leg-length discrepancy, Harris Hip Score, and complications like periprosthetic joint infections, dislocations, and nerve injuries were analyzed. A random effects model was employed for statistical analysis, with sensitivity analysis and metaregression applied in cases of high heterogeneity.

RESULTS

The included studies assessed 1,024 hips with a mean follow-up of 11 years, revealing improvements in Harris Hip Score and reductions in leg length discrepancy post-THA. However, notable challenges were noted, including a 10.7% rate of intraoperative fractures, a 1.8% periprosthetic joint infection rate, and a 5.8% dislocation rate. Osteolysis and aseptic loosening revisions were observed in 9.1 and 8% of cases, respectively. Heterotopic ossification occurred in 11.1% of patients. Nerve injury was reported in 4.2% of cases. With the use of metaregression, some factors for observed heterogeneity were identified.

CONCLUSIONS

Total hip arthroplasty (THA) in Crowe type IV DDH patients presents notable challenges, but can lead to substantial long-term improvements in patient-reported outcomes.

LEVEL OF EVIDENCE

IV.

Robotically Assisted vs. Manual Total Hip Arthroplasty in Developmental Hip Dysplasia: A Comparative Analysis of Radiological and Functional Outcomes

Background/Objectives: Developmental dysplasia of the hip (DDH), defined by the malalignment of the femoral head and acetabulum, is a major precursor to coxarthrosis, posing substantial challenges during total hip arthroplasty (THA). Patients with coxarthrosis secondary to DDH often exhibit acetabular bone insufficiency, which makes challenging surgical reconstruction difficult. This study aimed to compare the radiologic and functional outcomes of robotically assisted and conventional manual THA techniques in patients with coxarthrosis secondary to Crowe type III-IV DDH. Methods: This prospective study included 40 patients divided into robotically assisted (n = 20) and conventional manual (n = 20) THA groups. Evaluations encompassed hip pain (Visual Analogue Scale, VAS), function (Harris hip score and University of California, Los Angeles, activity scale), quality of life (Short Form-12), and prosthesis sensation (Forgotten Joint Score-12). Radiologic outcomes included acetabular inclination and anteversion angles. Femoral shortening, operative duration, and follow-up times were also analyzed. Results: Demographic characteristics did not differ between groups (p > 0.05). Robotically assisted THA exhibited a significantly longer operative time (171.40 ± 11.96 vs. 150.30 ± 14.67 min; p = 0.001) but a shorter follow-up (29.3 ± 8.51 vs. 52.95 ± 18.96 months; p = 0.001), without a difference in the amount of femoral shortening (p = 0.947). Despite the extended surgical duration, the two techniques achieved comparable radiologic outcomes, with no significant differences in acetabular inclination or anteversion angles (p > 0.05). Functional assessments, including Harris hip scores (73.85 vs. 73.95; p = 0.978), UCLA activity scores, and VAS, indicated similar efficacy between groups. SF-12 physical and mental quality of life and Forgotten Joint Score-12 prosthesis sensation did not differ between groups (p > 0.05). Conclusions: This study concludes that robotically assisted and conventional manual THA present similar radiologic and functional outcomes in patients with coxarthrosis secondary to Crowe type III-IV DDH, as displayed by comparable acetabular anteversion and inclination alignment, femoral shortening, hip function, pain, quality of life, and prosthesis sensation scores. While robotically assisted THA requires a longer operative time, its precision in implant placement may hold potential advantages for long-term outcomes, demanding further investigation in extended follow-up studies.

Morphological and bone defect mapping analysis of true acetabulum in Crowe type IV hip dysplasia

BACKGROUND

The primary aim of this study was to quantitatively analysis the acetabular morphological feature and 2D/3D coverage of the Crowe IV DDH hip, dividing into subgroups by the false acetabulum. The secondary aim was to propose a 3D bone mapping to determine acetabular bone defect analysis from the perspective of the implanted simulation.

METHODS

A total of 53 Crowe IV hips (27 hips without the false acetabulum in IVa group and 26 hips in IVb group) and 40 normal hips met the inclusion criteria and were retrospectively evaluated. Firstly, the anatomical size and volume of the acetabulum were measured quantitatively. Secondly, through the simulated implantation, morphological assessments of the true acetabulum included Cup-CE, Cup-Sharp, acetabular anteversion angle, and thickness of the medial wall. Last, Acetabular sector angles (ASAs) and the component coverage ratio were measured to provide coverage indices. Further, 3D bone mapping visualization was applied to determine the uncovered component portion distribution.

RESULTS

The anatomic shape and volume of the acetabular triangle were significantly smaller in Crowe IV hips. At the level of the acetabular component center, IVb acetabula were found to be more anteverted and abductive, with smaller Cup-CE and larger Cup-Sharp angles. The coverage sector angles in Crowe IVa hips were larger in the anterosuperior and superior direction, while smaller in the posterosuperior and posterior direction, with no subgroup difference in total component coverage. Both 3D bone mapping and correlation analysis reveal that posterosuperior and posterior bone stock is highly associated with the component coverage.

CONCLUSION

With the presence of the false acetabulum, there existed acetabular anteversion and segmental coverage distinctions between subgroups. During the acetabular reconstruction, management of posterosuperior and posterior bone stock was important for ideal component coverage.

Deciphering the past status and future tendency: a comprehensive scientometric study on developmental dysplasia of the hip

BACKGROUND

Developmental dysplasia of the hip is a common musculoskeletal disorder in newborns and young children, attracting considerable controversy. The purpose of the present study was to analyze the research trends and hotspots over the past three decades in this field.

METHODS

All related publications were collected from the Web of Science Core Collection from 1994 to 2023. Of these, characteristics of the top 50 cited articles for each decade (1994-2003, 2004-2013 and 2014-2023) were evaluated in detail. Visualized studies were operated via VOSviewer. GraphPad Prism and Microsoft Excel were used to perform statistical analysis. The characteristic of the present study is a cross-sectional study.

RESULTS

In total, 1,300 publications with 19,815 citations from 1994 to 2023 were selected. The number of publications increased significantly during the past three decades, from 23 in 1994 to 132 in 2023 (P < 0.0001). Studies with collaboration among institutions have raised significantly over time (P < 0.0001). The United States was the leading country to the top 50 publications in each decade. Publications with evidence level IV led the way every ten years. Visualized co-occurrence analysis clustered the keywords into four clusters: hip arthroplasty, congenital dislocation, ultrasound diagnosis and developmental dysplasia of the hip.

CONCLUSIONS

This study analyzed the global tendency and collaborations on developmental dysplasia of the hip over the past three decades. Even though the research trend has evolved to be collaborative with more multi-institutional publications and authors, studies with high evidence levels are still missing.

Mid to long-term survivorship of hip arthroplasty in patients 40 years and younger

BACKGROUND

Etiology of hip osteoarthritis (OA) and survival of hip arthroplasty in the young (below 40-years-old) remains poorly described. Furthermore, joint survivorship mid to long-term and PROMs according to the etiology are unclear. The study aims were to 1) identify the indications for arthroplasty in the below 40-years-old cohort; 2) define hip arthroplasty outcomes in the young and 3) test whether patients with sequelae of pediatrics hip disease have inferior outcome compared to other patients.

HYPOTHESIS

Our hypothesis was that hip arthroplasty is a viable option for managing hip disease in patients under 40, with excellent survival rates and outcomes.

MATERIAL AND METHODS

This is an IRB approved, retrospective, consecutive, multi-surgeon, cohort study from a single academic center. Indication for hip arthroplasty of 346 patients (410 hips) below 40-years-old were studied; 239 underwent THA (58%) and 171 hip resurfacing (42%). Patient, surgical and implant factors were tested for association with implant survivorship and functional outcome for hip arthroplasty performed with a follow-up of more than two years. Pediatric hip sequelae patients were compared for survival and PROMs with the rest of the cohort.

RESULTS

The most common etiology of OA was FAI (47%), followed by pediatric hip sequelae (18%). The 10-year survivorship was 97.2% ± 1.2, mean OHS was 45.1 ± 6.3 and mean HHS was 93.4 ± 12.6. The pediatric hip sequelae subgroup demonstrated no differences in 10-year survivorship and better PROMs compared to rest (OHS: 46.6 ± 3.8; HHS: 96.0 ± 8.5).

DISCUSSION

The most common aetiologies amongst the young with hip OA is FAI and pediatric hip sequelae. Hip arthroplasty in the young presents excellent 10-year survivorship and PROMs. Excellent survival and PROMs in the young with pediatric hip sequelae provide important information for decision-making in this challenging population.

LEVEL OF EVIDENCE

III; retrospective cohort study.

Radiographic factors affecting contralateral knee alignment in patients with dysplastic hip osteoarthritis

INTRODUCTION

Patients with dysplastic hip arthritis (DHA) often present with abnormal knee alignment. We investigate the factors influencing varus and valgus knee alignment on the contralateral side in patients with unilateral DHA.

METHODS

123 patients with unilateral DHA were enrolled between 2018 and 2022. Based on the hip-knee-ankle angle (HKAA), patients were divided into three groups: neutral group (HKAA <3° varus and valgus), varus group (>3° varus), and valgus group (>3° valgus). Demographics, radiographic parameters, and functional scores were compared between the groups.

RESULTS

There were 58, 44, and 21 patients in the neutral, varus, and valgus group, respectively. The varus group had a varus HKAA and hip adduction angle in the affected hip and a large femoral offset in the healthy hip. The valgus group had a valgus HKAA and large hip adduction angle in the affected hip and a small femoral offset in the healthy hip. In addition, the valgus group presented with pelvic obliquity, expressed as an upper pelvic tilt on the affected side. Multivariate analysis identified a varus HKAA in the affected hip (odds ratio [OR], 0.64; 95% confidence interval [CI]: 0.51-0.79; p < 0.01) as a factor associated with the varus group, while pelvic obliquity (OR, 0.69; 95% CI: 0.53-0.89; p = 0.01) was associated with the valgus group. The varus and valgus groups had significantly worse functional scores than the neutral group.

CONCLUSIONS

This study demonstrated that varus and valgus alignments of the contralateral knee with unilateral DHA were associated with radiographic parameters and hip function.

Staged Hip Arthroscopy and Periacetabular Osteotomy in Active Patients Aged 45 Years and Older Produce Comparable Improvements in Outcome Scores to Younger Patients

PURPOSE

To determine staged hip arthroscopy and periacetabular osteotomy (PAO) mid-term outcomes in active patients aged 45 years and older compared with a younger group.

METHODS

All patients aged 45 years and older who underwent staged arthroscopy and PAO between 2015 and 2021 were retrospectively analyzed and compared with a case-matched control group of younger patients. All patients underwent at least 6 months of nonoperative management prior to surgery. Prior to PAO, all patients underwent hip arthroscopy to address any intra-articular pathology. The experimental group consisted of patients with dysplasia aged 45 years and older without significant osteoarthritis who underwent PAO and reported patient-reported outcomes for a minimum of 1 year postoperatively. Patient-reported outcomes were quantified using the International Hip Outcome Tool 12 (iHOT-12) score and Non-arthritic Hip Score (NAHS).

RESULTS

The cohort consisted of 35 patients (44 hips) with a mean age of 49.4 ± 3.8 years. The lateral center-edge angle significantly improved from preoperatively (20.1° ± 4.5°) to postoperatively (33.2° ± 3.2°, P < .001). The mean follow-up period in the PAO cohort aged 45 years and older was 2.80 years (standard deviation, 1.3 years) postoperatively. Patients reported significant improvements in the iHOT-12 score (36.6 ± 14.1 preoperatively vs 81.2 ± 21.0 at latest follow-up, P < .001) and NAHS (59.2 ± 15.5 preoperatively vs 87.4 ± 13.1 at latest follow-up, P < .001). The older cohort did not report significantly different iHOT-12 scores compared with the control group at any point, and age did not significantly affect either outcome score (P > .05).

CONCLUSIONS

Patients aged 45 years and older reported a statistically significant improvement in hip function and pain after staged hip arthroscopy and PAO, with outcome scores comparable to a younger cohort. Our findings show that appropriately selected older patients with dysplasia without significant pre-existing hip osteoarthritis experience clinically meaningful improvements in hip pain and function after hip preservation surgery.

LEVEL OF EVIDENCE

Level III, retrospective, comparative case series.

Influence of hip prosthesis position on postoperative gait in symptomatic hip osteoarthritis secondary to hip dysplasia patients after primary total hip arthroplasty: a short-term follow-up study

BACKGROUND

The aim of this study was to analyze the influence of the positioning of the components of total hip arthroplasty (THA) evaluated by the acetabular anteversion (AA) and femoral anteversion (FA) angle on postoperative gait in patients with symptomatic hip osteoarthritis secondary to hip dysplasia undergoing THA.

METHODS

Between May 2023 and May 2024, patients with symptomatic hip osteoarthritis secondary to hip dysplasia (Crowe Type I and IV) who underwent THA were enrolled in the study. The AA angle and FA angle were measured by computer tomography (CT). Gait data were determined by using the Dynamic Right Gait & Posture analysis system. The relationship between FA, AA and gait data was analyzed by Pearson correlation test, subgroup Pearson correlation test, multiple linear regression.

RESULTS

A total of 40 patients (45hips) were included in the study. Compared with preoperative, the patient's postoperative foot progression angle, foot contact angle, plantarflexion velocity, swing foot speed, gait velocity, cadence, stride length were significantly improved. Preoperative FA is significantly different from postoperative FA (P < 0.05), while the difference between preoperative and postoperative AA is not significant. BMI, Crowe Type, AA were related to change of cadence. The less the postoperative AA of patients, and the more the cadence in the postoperative gait of patients.

CONCLUSION

Our study showed that THA could improve the gait function of patients with symptomatic hip osteoarthritis secondary to hip dysplasia. Adjusting AA lower could obtain a much more postoperative cadence.

Single-Taper Conical Tapered Stem in Total Hip Arthroplasty for Primary Osteoarthritis: A Comparative Long-Term Registry Evaluation

Background/Objectives: Single-taper conical tapered stems (STCTSs) are possible options for femoral reconstruction in THA performed for primary osteoarthritis, but outcomes are poorly ascertained. A specific STCTS in THA performed for primary osteoarthritis was investigated and compared to a control group including all the other cementless stems, aiming to assess the following: (1) the survival rates of the two cohorts and the hazard ratios for failure; (2) the survival rates and the hazard ratios for failures for stem failure, stem aseptic loosening, and periprosthetic fracture. Methods: A regional arthroplasty registry study evaluating a specific STCTS in THA performed for primary osteoarthritis was designed. A control group including all the other cementless stems was considered. Results: In total, 1773 STCTSs were compared to 37,944 cementless stems. The cumulative survivorship of the STCTS cohort was 95.6% at 10 years and 92.7% at 15 years, which was not different to the control group (p = 0.252). After age stratification, the hazard ratio for STCTS failure was not different to the control group. With stem revision as the endpoint, the STCTS cohort outperformed the control group (at 10 years, 98% versus 96.8%; p < 0.001). The STCTSs achieved better survival rates in females <65 years (p = 0.023). With stem aseptic loosening as the endpoint, the survival rates did not differ between the two cohorts (p = 0.085), as well as the adjusted hazard ratios (p = 0.264). With periprosthetic fracture as the endpoint, the survival rates were better for the STCTSs (p < 0.001). Conclusions: STCTSs in THA for primary osteoarthritis provided dependable long-term outcomes, not inferior to all the other cementless stems with various designs.

Total Hip Arthroplasty in Patients Who Have Crowe Type IV Developmental Dysplasia of the Hip: A Systematic Review

BACKGROUND

Developmental dysplasia of the hip (DDH) is one of the principal causes of secondary hip osteoarthritis, giving rise to considerable pain, impaired mobility, and a reduced quality of life. The optimal approach to managing individuals who have Crowe type IV DDH remains controversial. This study aimed to review the existing literature on the application of total hip arthroplasty (THA) as a treatment modality for Crowe type IV DDH, assessing its efficacy in addressing this severe hip deformity.

METHODS

A comprehensive search across the PubMed, Scopus, and Web of Science databases identified relevant studies. Inclusion criteria encompassed investigations reporting outcomes of THA in Crowe type IV DDH patients. Data extraction and quality assessment were performed independently by 2 reviewers. Utilizing R software, the prevalence of THA complications was analyzed through proportion analysis, employing the inverse variance method.

RESULTS

In this systematic review, a total of 74 studies were included, comprising a collective sample size of 2,829 patients (3,356 hips) diagnosed with Crowe type IV DDH. The posterior or posterolateral approach was the most commonly utilized surgical approach, followed by the lateral Hardinge and direct lateral approaches. The majority of studies have employed subtrochanteric osteotomies. Notably, post-THA, leg length discrepancy decreased, Trendelenburg sign resolved, and back pain was reduced. Patient-reported outcome measures like the Harris Hip Score improved significantly. The pooled prevalence rates of major postoperative complications were also assessed, including dislocation (7.2%), revision (8.7%), intraoperative fractures (10.5%), loosening (5.7%), nerve paralysis (5.6%), deep vein thrombosis (3.6%), infection (3.8%), heterotopic ossification grade 2 and above (6.1%), and a complicated patient rate of 11.0%.

CONCLUSIONS

Synthesizing diverse study data, an overview of THAs performance emerges, demonstrating significant enhancements in function, pain reduction, quality of life, and the correction of substantial leg length discrepancy. While THA has shown positive outcomes, instances of complications have been reported. The decision to undergo THA should involve a collaborative assessment between the surgeon and the patient, considering potential benefits and complications.

Is step-cut shortening osteotomy a better choice than transverse osteotomy for total hip arthroplasty for Crowe type III-IV hip dysplasia?

INTRODUCTION

Total hip arthroplasty for developmental hip dysplasia is a challenging surgery due to anatomic abnormalities. Crowe III and Crowe IV hip dysplasia generally necessitates a subtrochanteric shortening osteotomy. Transverse and step-cut osteotomy are the most common procedures for shortening of femur although there is still no consensus which one is a superior method. The objective of this study was to demonstrate whether transverse or step-cut osteotomy is superior in hips who undergo arthroplasty for high riding hip dysplasia.

HYPOTHESIS

Our hypothesis was that higher rates of union would be achieved in patients with Crowe III-IV hip dysplasia when the step-cut osteotomy was performed compared to transverse osteotomies.

MATERIAL AND METHODS

A total of 99 hips from 90 patients (9 bilateral, 81 unilateral; 79 female, 11 male), each with a minimum follow-up duration of two years, were included in this study. The hips were classified as Crowe III (n=16) or IV (n=83). All hips were implanted cementless. Transverse or step-cut osteotomy was chosen for osteotomy type. The clinical and functional outcomes were assessed using the Harris Hip Score (HHS), limb length discrepancy (LLD), and limping. The complications and management of these were noted. The union rates were compared between osteotomy types.

RESULTS

The mean age at surgery was 48.8 (range, 21-79 years). The follow-up period was 64.3 months in average (range, 24 to 192 months). The mean Harris Hip Score before surgery was 35.6 (range, 18-50), and increased to 88.1 (range, 61-98) points at the most recent follow-up. The preoperative leg length discrepancy (LLD) measured 5.3cm (with a range of 3 to 6.8), while the postoperative LLD reduced to 0.8cm (with a range of 0 to 1.6). There were a total of 38 complications in 35 patients out of 99 cases, resulting in a complication rate of 38.4%. The most frequent complication observed was intraoperative femoral fractures, occurring in 13 cases. Residual limping was seen in 73.7% of all. Step-cut osteotomy was performed in 64 hips (35 CDH stem [Zimmer Biomet, Warsaw, IN, USA], 29 Wagner Cone stem [Zimmer Biomet, Warsaw, IN, USA]) and, transverse in 35 hips (22 CDH, 13 Wagner Cone). Six hips had nonunion problem and all of them were operated with a step-cut osteotomy (z-score: -7.12 and p<0.00001, Mann-Whitney U Test).

CONCLUSION

Transverse osteotomy may be a better option while performing a shortening subtrochanteric level osteotomy for total hip arthroplasty for Crowe III-IV hips.

LEVEL OF EVIDENCE

Level III; observational retrospective cohort study.

Total hip arthroplasty with subtrochanteric femoral shortening osteotomy using a monoblock cylindrical cementless stem for severe developmental hip dysplasia (Crowe type III, IV)

BACKGROUND

Treatment of patients with Crowe type III and IV dislocated hips is challenging because of the hip deformity in these patients. In addition to the usual total hip replacement, shortening and reduction of the femur are often required. We herein report on our surgical technique using a monoblock cylindrical cementless stem and a direct lateral approach.

METHODS

This study included patients with a diagnosis of severe developmental dysplasia of the hip (Crowe types III and IV) who underwent primary total hip arthroplasty at our hospital from August 2019 to January 2022. Eleven hips of seven patients were treated. All patients underwent horizontal osteotomy using a monoblock cylindrical cementless stem and a direct lateral approach. Complications such as dislocation, infection, and implant dropout were evaluated. In addition, the clinical assessment included the hip range of motion at the last observation and hip function based on the Japanese Orthopaedic Association (JOA) hip score and the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ).

RESULTS

The average operation time was 224 min (range, 194-296 min), and the average bleeding amount was 396.1 g (range, 20-1010 g). The main complications were acetabular implant dislocation, postoperative dislocation, intraoperative arterial injury, intraoperative proximal femoral fracture, subsidence of femoral implant. and postoperative pulmonary infarction, which occurred in one patient each.

CONCLUSION

Total hip arthroplasty for Crowe type III and IV hips is associated with various surgical technical difficulties because of its anatomical characteristics. While patients with severe osteoporosis are contraindicated, the use of a cylindrical monoblock cementless stem and the direct lateral approach makes it possible to simplify the procedure for shortening the femur and increase the indications for surgery.

LEVEL OF EVIDENCE

Therapeutic Level Ⅳ.

Dysplastic Hips That Are Too Late for Periacetabular Osteotomy Are Not Too Early for Total Hip Arthroplasty

BACKGROUND

Total hip arthroplasty (THA) is often performed in symptomatic patients who have hip dysplasia and do not qualify for periacetabular osteotomy. The impact of osteoarthritis (OA) severity on postoperative outcomes in dysplasia patients who undergo THA is not well described. We hypothesized that dysplasia patients who have mild OA have slower initial recovery postoperatively but similar one-year patient-reported outcome measures (PROMs) compared to dysplasia patients who have severe OA.

METHODS

We performed a retrospective review at a single academic institution over a 6-year period of patients who have dysplasia who underwent THA compared to patients who have primary OA who underwent THA. There were 263 patients who had dysplasia, compared to 1,225 THA patients who did not have dysplasia. Within the dysplasia cohort, we compared PROMs stratified by dysplasia and OA severity. The diagnosis of dysplasia was verified using the radiographic lateral center edge angle. A minimum one-year follow-up was required. The PROMs were collected through one year postoperatively. Logistic and linear regression models were used, adjusting for age, sex, body mass index, and Charlson comorbidity index.

RESULTS

No significant differences were found in postoperative PROMs or revision rates (P = .58). When stratified by dysplasia severity, patients who had lower lateral center edge angle had more improvement in physical function scores from preoperative to 2 weeks (P < .01) and higher physical function scores at 2 weeks (P = .03). When stratified by OA severity, patients who had a worse Tönnis score had more improvement in physical function scores from preoperative to 2 weeks (P < .01). Recovery curves in dysplasia patients based on dysplasia and OA severity were not significantly different at 6 weeks, 1 year, and 2 years postoperative.

CONCLUSIONS

Patients who had hip dysplasia and mild OA had similar recovery curves compared to those who had severe OA or who did not have dysplasia. We believe that THA is a reasonable surgical intervention for symptomatic dysplasia patients who have mild arthritis and do not qualify for periacetabular osteotomy.

Pediatric hip disorders are not associated with an increased 10-year revision risk after total hip arthroplasty under the age of 55: results from the Dutch Arthroplasty Register

BACKGROUND AND PURPOSE

 Developmental dysplasia (DDH) and Legg-Calvé-Perthes disease (LCPD) are common indications for total hip arthroplasty (THA) at a young age, and may be associated with increased revision risk. We aimed to investigate the 10-year cumulative aseptic cup revision and overall revision risk of THA, and investigated whether these are increased compared with THA for primary osteoarthritis (OA) in patients below 55 years.

METHODS

 All THAs (2007-2019) in patients under the age of 55 for the indications OA, DDH, and LCPD were extracted from the Dutch Arthroplasty register. The 10-year cumulative incidences of aseptic cup failure and overall revision were assessed for the 3 groups, with death as a competing risk. Cox regression analysis was used.

RESULTS

 24,263 THAs were identified: 20,645 (85%) for OA, 3,032 (13%) for DDH, and 586 (2%) for LCPD. The 10-year cumulative revision risk for aseptic cup failure was 3.4% (95% confidence interval [CI] 3.0-3.8) for OA, 3.4% (CI 2.4-3.4) for DDH, and 1.7% (CI 0.2-3.1) for LCPD. The 10-year cumulative overall revision risk was 6.0% (CI 5.6-6.5) for OA, 6.0% (CI 4.9-7.2) for DDH, and 5.1% (2.7-7.5) for LCPD. The multivariable Cox regression analysis for aseptic cup failure yielded hazard ratios of 0.7 (0.5-1.2) for DDH, and 0.8 (0.3-2.1) for LCPD compared with OA. No statistically significant differences for overall revision were found.

CONCLUSION

 THA performed for DDH or LCDP in patients under the age of 55 was not associated with a statistically significant increased risk of aseptic cup revision or overall revision, compared with THA performed for primary OA in the same age group.

Are robotic-assisted and computer-navigated total hip arthroplasty associated with superior outcomes in patients who have hip dysplasia?

Introduction

Robotic-assisted (RA) and computer-navigated (CN) total hip arthroplasty (THA) have been demonstrated to improve component placement accuracy compared to manual THA (mTHA) for primary osteoarthritis. As hip dysplasia presents several additional challenges in component placement accuracy and leg length discrepancy (LLD) correction during THA, a systematic review was conducted to evaluate whether utilizing these platforms may be associated with superior outcomes over mTHA in patients who have hip dysplasia.

Methods

PubMed, Medline, EBSCOhost, and Google Scholar were searched on September 13, 2023 to identify comparative studies published after January 1, 2000 that evaluated outcomes of RA-THA or CN-THA in patients who have hip dysplasia. The query yielded 197 unique articles, which were screened for alignment with the study aims. After screening, 10 studies fulfilled all inclusion criteria, comprising 946 patients. Risk of bias was evaluated via the Methodological Index for Nonrandomized Studies tool, and the mean score was 21.2 ± 1.5.

Results

Both RA-THA and CN-THA were not associated with improved acetabular anteversion and inclination when evaluating Crowe I-IV types altogether compared to mTHA, but studies reported improved accuracy for each Crowe I and II cases when assessed individually. While studies reporting acetabular cup placement within the Lewinnek and Callanan safe zones consistently found higher odds of accurate positioning for RA-THA versus mTHA, accuracy in achieving targeted center of rotation was mixed. Also, studies reported no difference in LLD restoration for RA-THA and CN-THA compared to mTHA. While operative time may be increased when utilizing these platforms, they may also expedite specific sequences, offsetting most of the increase in operative time.

Conclusion

This review highlights the advantages of RA-THA and CN-THA for patients who have DDH, particularly when treating Crowe I and II types as superior radiographic outcomes were achieved with these intraoperative technologies. However, there remains a need for studies to investigate whether this results in patient-reported outcome measures.

Total Hip Replacement and Femoral Nail Lengthening for Hip Dysplasia and Limb Length Discrepancy: A Literature Review

Developmental dysplasia of the hip (DDH) is a serious condition resulting in inadequate acetabular development, distorted bone configuration, and substantially altered hip biomechanics. An extensive leg length discrepancy (LLD) is commonly encountered in such cases, making a total hip arthroplasty (THA) procedure extremely challenging. Although good results in terms of patients' satisfaction, implant survival rates and overall improved quality of life have been reported, complication rates are considerably higher than primary THA procedures performed for idiopathic osteoarthritis. Reconstructing a dysplastic hip arthrosis and equalizing a preexisting LLD is a technically demanding procedure that is associated with significant bone and soft tissue complications. Intramedullary lengthening through motorized nails has become increasingly popular to address difficult cases with extensive LLD following THA in recent years. However, limited data on femoral lengthening procedures implemented following THA are available considering complications, radiological results, and patient-reported outcomes following staged THA and subsequent femoral lengthening using a femoral magnetically-driven intramedullary lengthening nail. We performed a literature review of the past 10 years in PubMed using the terms neglected hip dislocation, DDH, THA, and intramedullary lengthening nail as keywords. A total amount of eight cases addressing LLD through a telescoping intramedullary nail following THA in DDH have been reported in recent literature. All eight patients underwent primary THA for DDH followed by the implantation of the intramedullary lengthening nail. The mean THA was lengthened by 28.9 mm (from 13.0 to 45.0). The mean time for nail implantation after THA was 11.1 months (from 3.5 to 21). The mean time for lengthening per day through the nail was 0.94 mm (from 0.65 to 1.0) from 26 days to 70 days, and the mean lengthening through the nail was 37.6 mm (from 24.0 to 70.0). Good union and consolidation rates were reported by the authors, while there were no complications. The intramedullary distraction osteogenesis method with a telescopic rod can be an effective method to manage leg length discrepancies while avoiding soft tissue complications in challenging cases of DDH.

Effects of lower limb length discrepancy on spinopelvic compensation following total hip arthroplasty in patients with developmental dysplasia of the hip

BACKGROUND

Limited research has examined the impact of lower limb length discrepancy (LLLD) alteration on spinopelvic compensation in individuals with developmental dysplasia of the hip (DDH). This study aimed to investigate the effects of LLLD on spinopelvic compensation following total hip arthroplasty (THA) and elucidate the complex biomechanical adaptations in the spinopelvic structures.

METHODS

A retrospective review of DDH patients undergoing THA from January 2014 to December 2021 categorized individuals with Crowe type I and II into the low dislocation group (LDG, n = 94) and those with Crowe type III and IV into the high dislocation group (HDG, n = 43). Demographic data, as well as preoperative, postoperative, and last follow-up imaging data, including lower limb length (LLL), sacral obliquity (SO), iliac obliquity (IO), hip obliquity (HO), Cobb angle, apical vertebral translation (AVT), and coronal decompensation (CD), were collected for analysis.

RESULTS

Patients in the LDG had a significantly higher surgical age and shorter disease duration (P<0.05). In LDG, patients exhibited substantial postoperative reductions in LLLD, SO, IO, and HO (P<0.05), while Cobb Angle, AVT, and CD showed no statistically significant changes (P>0.05). The variation in LLLD correlated significantly with the variations in SO, IO, and HO (P<0.05). Postoperative outcomes in the HDG demonstrated marked decreases in LLLD, SO, IO, HO, and CD (P<0.05), with no significant change in Cobb angle and AVT (P>0.05). The variation in LLLD correlated significantly with the variations in SO, IO, HO, and CD (P<0.05).

CONCLUSIONS

THA effectively reduces LLLD in patients with DDH, and the variation in LLLD correlates meaningfully with the recovery of spinopelvic compensatory mechanisms.

A New Method to Predict Postoperative Stem Anteversion in Total Hip Arthroplasty for Developmental Dysplasia of the Hip

BACKGROUND

Preoperative evaluation of femoral anteversion to predict postoperative stem anteversion aids the selection of an appropriate prosthesis and optimizes the combined anteversion in total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH). The conventional prediction methods are based on the femoral anteversion measurement at the location of the femoral head and/or neck. However, varied differences between femoral anteversion and postoperative stem anteversion were demonstrated. This study investigated the predictive role of a new method based on the principle of sagittal three-point fixation.

METHODS

From January 2017 to December 2018, a total of 133 DDH hips that underwent THA were retrospectively analyzed. There were 76 Crowe type I, 27 type II, and 30 type III hips. The single-wedge stem was used in 49 hips, and the double-wedge stem was used in 84 hips. Preoperative native femoral anteversion at the femoral head-neck junction, anterior cortex anteversion at 2 levels of the lesser trochanter, posterior cortex anteversion at 5 levels of the femoral neck, and postoperative stem anteversion were measured using two-dimensional computed tomography. Predictive anteversion by the new method was calculated as the average anteversion formed by the anterior cortex at the lesser trochanter and the posterior cortex at the femoral neck.

RESULTS

For hips with different neck heights, different Crowe types, different stem types, or different femoral anteversions, native femoral anteversion showed widely varied differences and correlations with stem anteversion, with differences ranging from -1.27 ± 8.33° to -13.67 ± 9.47° and correlations ranging from 0.122 (p = 0.705, no correlation) to 0.813. Predictive anteversion formed by the anterior cortex at the lesser trochanter proximal base and posterior cortex 10 mm above the lesser trochanter proximal base showed no significant difference with stem anteversion, with less varied differences (0.92 ± 7.52°) and good to excellent correlations (r = 0.826).

CONCLUSION

Adopting our new method, predictive anteversion, measured as the average anteversion of the anterior cortex at the lesser trochanter proximal base and posterior cortex 10 mm above the lesser trochanter proximal base, predicted postoperative stem anteversion more reliably than native femoral anteversion.

Robotic-assisted total hip arthroplasty in patients with developmental dysplasia of the hip

PURPOSES

Due to the morphological diversity of deformities, technical difficulties, improperly designed components, and so on, THA remains a challenging task in dysplastic hips, especially in highly dislocated hips. The purpose of this study was to comprehensively evaluate the clinical outcomes of robot-assisted THA in patients with DDH through a large cohort study, including the precision of acetabular cup positioning, indicators of inflammatory response, indicators of muscle damage, and complications.

METHODS

We retrospectively analyzed patients with DDH who underwent THA in our prospectively constructed joint registry between August 2018 and August 2022. Finally, 147 manual THAs and 147 robotic-assisted THAs were included in the final analysis. Patient demographics, indicators of inflammation, indicators of muscle damage, operative time, Harris hip scores (HHS), and forgotten joint score (FJS) were recorded for analysis. The precision of the positioning of the acetabular component was assessed with plain radiographs.

RESULTS

In the Crowe II/III groups, the reconstructed center of rotation (COR) in the robotic-assisted group was closer to the anatomical COR with less variation than the manual group (absolute horizontal distances of COR 3.5 ± 2.8 vs. 5.4 ± 4.9 mm, p < 0.05; absolute vertical distances of COR 6.4 ± 4.1 vs. 11.7 ± 8.2 mm, p = 0.001). For all Crowe subtypes, the robotic-assisted THA significantly increased the proportion of acetabular cups located in the safety zone within 5° (all p < 0.05). Interleukin-6 and creatine kinase levels were slightly lower and significantly different in the robotic-assisted group at three days postoperatively (all p < 0.05).

CONCLUSIONS

Compared to the manual technique, the robot-assisted technique improved the precision and reproducibility of acetabular component positioning, particularly in DDH patients with Crowe types II/III. The robotic-assisted technique did not increase operative time, bleeding, complications, or revision rates, and had a slighter early inflammatory response and muscle damage.

In-hospital complications and readmission patterns in 13,937 patients with developmental dysplasia of the hip undergoing total hip arthroplasty: Evidence from the Chinese national database

PURPOSE

Clarifying the prognosis and readmission patterns of patients with developmental dysplasia of the hip (DDH) following total hip arthroplasty (THA) would provide important references for clinical management for this population. Using the Chinese national inpatient database (i.e., Hospital Quality Monitoring System [HQMS]), we aimed to compare in-hospital complications and readmission patterns following THA in patients with DDH and primary osteoarthritis (OA).

METHODS

Patients undergoing THA for DDH and OA between 2013 and 2019 were identified using the HQMS. Demographics and clinical characteristics were compared between the two groups. After propensity score matching, in-hospital complications and readmission patterns were compared using a logistic regression model.

RESULTS

According to the analysis of 13,937 propensity-score matched pairs, there were no significant differences in the incidence of in-hospital death (0.01 % vs 0.04 %, P = 0.142), transfusion (8.09 % vs 7.89 %, P = 0.536), wound infection (0.31 % vs 0.25 %, P = 0.364), deep venous thrombosis (0.45 % vs 0.43 %, P = 0.786), pulmonary embolism (0.03 % vs 0.05 %, P = 0.372) or all-cause readmission (2.87 % vs 3.12 %, P = 0.219) between two groups. However, DDH patients had higher surgical readmission rates than OA patients (1.43 % vs 1.14 %, P = 0.033). When analyzing causes of surgical readmission, DDH patients had increased risk of dislocation (0.37 % vs 0.21 %, P = 0.011) and aseptic loosening (0.17 % vs 0.07 %, P = 0.024) than OA patients.

CONCLUSION

DDH patients had an increased risk of surgical readmission following THA, mainly driven by dislocation and aseptic loosening, which should be recognized and appropriately prevented.

Treatment of bilateral developmental dysplasia of the hip joint with an improved technique: A case report

BACKGROUND

Developmental dysplasia of the hip (DDH) is a common osteoarticular deformity in pediatric orthopedics. A patient with bilateral DDH was diagnosed and treated using our improved technique "(powerful overturning acetabuloplasty)" combined with femoral rotational shortening osteotomy.

CASE SUMMARY

A 4-year-old girl who was diagnosed with bilateral DDH could not stand normally, and sought surgical treatment to solve the problem of double hip extension and standing. As this child had high dislocation of the hip joint and the acetabular index was high, we changed the traditional acetabuloplasty to "powerful turnover acetabuloplasty" combined with femoral rotation shortening osteotomy. During the short-term postoperative follow-up (1, 3, 6, 9, 12, and 15 months), the child had no discomfort in her lower limbs. After the braces and internal fixation plates were removed, formal rehabilitation training was actively carried out.

CONCLUSION

Our "powerful overturning acetabuloplasty" combined with femoral rotational shortening osteotomy is feasible in the treatment of DDH in children. This technology may be widely used in the clinic.

Direct Anterior Approach in Total Hip Arthroplasty for Severe Crowe IV Dysplasia: Retrospective Clinical and Radiological Study

Background and Objectives: total hip arthroplasty (THA) for Crowe IV hip dysplasia poses challenges due to severe leg shortening, muscle retraction and bone stock issues, leading to an increased neurological complication, and revision rate. The direct anterior approach (DAA) is used for minimally invasive THA but its role in Crowe IV dysplasia is unclear. This retrospective study examines if DAA effectively restores hip biomechanics in Crowe IV dysplasia patients with <4 cm leg length discrepancy, managing soft tissue and yielding functional improvement, limb length correction, and limited complications. Materials and Methods: 19 patients with unilateral Crowe IV hip osteoarthritis and <4 cm leg length discrepancy undergoing DAA THA were reviewed. Surgery involved gradual soft tissue release, precise acetabular cup positioning, and stem placement without femoral osteotomy. Results: results were evaluated clinically and radiographically, with complications recorded. Follow-up revealed significant Harris Hip Score and limb length discrepancy improvements. Abductor muscle insufficiency was present in 21%. The acetabular component was accurately placed, centralizing the prosthetic joint's rotation. Complications occurred in 16% of cases, including fractures, nerve issues, and infection. DAA in THA showcased positive outcomes for hip function, limb length, and biomechanics in Crowe IV dysplasia. Conclusions: the technique enabled accurate cup positioning and rotation center adjustment. Complications were managed well without implant revisions. DAA is a viable option for Crowe IV dysplasia, restoring hip function, biomechanics, and reducing limb length discrepancy. Larger, longer studies are needed for validation.

Medial Protrusio Technique Versus Structural Autologous Bone-Grafting Technique in Total Hip Arthroplasty for Crowe Type II to III Hip Dysplasia

BACKGROUND

It is unclear whether acetabular reconstruction techniques have any impact on clinical outcomes. This study aimed to determine (1) whether acetabular reconstruction techniques influenced the position of the acetabular cup and (2) whether clinical outcomes based on the acetabular reconstruction techniques differ in patients undergoing total hip arthroplasty (THA) with Crowe II to III developmental dysplasia of the hip.

METHODS

This was a retrospective analysis of prospectively collected data from 69 patients (74 hips) who were treated with cementless THA using medial protrusio technique (MPT) or structural autologous bone-grafting technique (SABT). There were 39 patients (41 hips) included in the MPT group and 30 patients (33 hips) in the SABT group. Clinical and radiographic outcomes were evaluated.

RESULTS

All patients were followed up for at least 3 years. There were similar results between the 2 groups in terms of blood loss, Harris hip score, leg length discrepancy, cup inclination, cup anteversion, and proportion of cup coverage (P > .05). The operative time was significantly longer in the SABT group compared with the MPT group (P < .001). The postoperative vertical center of rotation was significantly higher in the MPT group compared with the SABT group (P = .001), and postoperative horizontal center of rotation was significantly shallower in the SABT group compared with the MPT group (P < .001).

CONCLUSION

The MPT and SABT provide similar clinical and radiographic outcomes in the management of Crowe II to III developmental dysplasia of the hip by cementless THA. However, the MPT has the advantage of a shorter operative time, whereas the SABT is more conducive to placing the acetabular cup in an anatomic position.

LEVEL OF EVIDENCE

Level III, Therapeutic, Case-Control Study.

Primary Staged Bilateral Total Hip Arthroplasty in a Patient With Short Stature and Hartofilakidis Type I Developmental Dysplasia of the Hip

Syndromes associated with osteochondrodysplasia, short stature, and DDH are rarely reported in the literature. Total hip arthroplasty (THA) in such cases is a complex procedure with a high rate of complications and difficulties. In this case report, we describe the staged bilateral complex primary THA of a patient with the rare occurrence of a syndrome involving osteochondrodysplasia and DDH, highlighting the surgical challenges and importance of the right prosthesis selection.

Conventional versus lateral fasciotomy for prevention of lateral femoral cutaneous nerve injury in the non-fan-type nerve in total hip arthroplasty with direct anterior approach

Aims

Lateral femoral cutaneous nerve (LFCN) injury is a potential complication after the direct anterior approach for total hip arthroplasty (DAA-THA). The aim of this study was to determine how the location of the fasciotomy in DAA-THA affects LFCN injury.

Methods

In this trial, 134 patients were randomized into a lateral fasciotomy (n = 67) or a conventional fasciotomy (n = 67) group. This study was a dual-centre, double-blind, prospective randomized controlled two-arm trial with parallel group design and a 1:1 allocation ratio. The primary endpoint was the presence of LFCN injury, which was determined by the presence of numbness, decreased sensation, tingling, jolt-like sensation, or pain over the lateral aspect of the thigh, excluding the surgical scar, using a patient-based questionnaire. The secondary endpoints were patient-reported outcome measures (PROMs) using the Western Ontario and McMaster Universities osteoarthritis index (WOMAC), Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ), and the Forgotten Joint Score-12 (FJS-12). Assessments were obtained three months after surgery.

Results

The incidence of LFCN injury tended to be lower in the lateral fasciotomy group (p = 0.089). In the lateral fasciotomy group, there were no significant differences in the mean PROM scores between patients with and without LFCN injury (FJS-12: 54.42 (SD 15.77) vs 65.06 (SD 26.14); p = 0.074; JHEQ: 55.21 (SD 12.10) vs 59.72 (SD 16.50); p = 0.288; WOMAC: 82.45 (SD 6.84) vs 84.40 (SD 17.91); p = 0.728). In the conventional fasciotomy group, there were significant differences in FJS-12 and JHEQ between patients with and without LFCN injury (FJS-12: 43.21 (SD 23.08) vs 67.28 (SD 20.47); p < 0.001; JHEQ: 49.52 (SD 13.97) vs 59.59 (SD 15.18); p = 0.012); however, there was no significant difference in WOMAC (76.63 (SD 16.81) vs 84.16 (SD 15.94); p = 0.107).

Conclusion

The incidence of LFCN injury at three months after THA was comparable between the lateral and conventional fasciotomy groups. Further studies are needed to assess the long-term effects of these approaches.

Intraoperative blood loss and haemoglobin drop in patients with developmental dysplasia of the hip in Jordan undergoing total hip arthroplasty

PURPOSE

Developmental dysplasia of the hip is still a prevailing secondary cause of early hip osteoarthritis in Jordan. Dysplastic coxarthrosis can result in significant and disabling hip pain with impaired patient's functionality. Due to this significant morbidity, patients ultimately need total hip arthroplasty, which offers the best functional outcome. Significant anatomical aberrances do exist in such hips as a result of old dysplasia; such pathoanatomical changes can complicate an already difficult surgery and lead to significant intraoperative blood loss and haemoglobin drop postoperatively. So, the aim of this research was to investigate on the intraoperative blood loos, and postoperative haemoglobin drop in these patients.

METHODS

A cross-sectional study design was adopted, and 162 patients with advanced hip osteoarthrosis secondary to developmental dysplasia of the hip (DDH) were studied. We studied predictors of hemoglobin drop and blood loss and linked some variables to this outcome variable using different statistical tests.

RESULTS

Our results showed a positive correlation between blood loss and BMI (r = 0.27, p = 0.73), haemoglobin drop and duration of surgery (r = 0.14, p = 0.07), length of hospital stay and duration of surgery (r = 0.25, p = 0.001). No significant differences between outcome measures (blood loss, haemoglobin drop, and duration of surgery) between males and females (p = 0.38, 0.93, 0.77 respectively). However, there was a statistically significant differences in haemoglobin drop among patients underwent general versus spinal anaesthesia (p = 0.03). additionally, there was a statistically significant association in length of hospital stay among smokers (p = 0.03), and patients who didn't prescribed anxiolytic preoperatively (p = 0.008).

CONCLUSION

Haemoglobin drop and blood loss in patients with dysplastic coxarthrosis were linked to increased preoperative BMI. Use of preoperative anxiolytics, and being non-smoker decreased the length of hospital stays. General anaesthesia was associated with more haemoglobin drop as well.

Single-taper conical tapered stem in total hip arthroplasty for developmental dysplasia of the hip: A long-term evaluation

INTRODUCTION

Conical tapered stems may be useful implants to manage the reconstruction of complex dysplastic anatomies. The aims of this paper were to assess: 1) the preoperative CT features of the dysplastic femurs; 2) survival rates, complications and reasons for revision; 3) the clinical outcomes; 4) the radiographic outcomes of single-taper conical stems in dysplasia (defined as center edge angle < 20°) at a long-term follow-up.

HYPOTHESIS

Monoblock conical stem provides a 10-year survival rate of at least 95%, with excellent clinical outcomes and bony ingrowth.

MATERIALS AND METHODS

In total, 100 THAs in 85 patients (15 bilateral cases) were enrolled. The average age of the patients at surgery was 50.9±11.5 years. Assessment of the native femoral morphology was performed using CT-scan, coronal (neck-shaft angle, offset, center of rotation position) and axial parameters (anteversion, mediolateral and anteroposterior femoral diameters). Clinical (HHS score) and radiological (osseointegration, subsidence and offset reconstruction) outcomes were evaluated at the last available follow-up.

RESULTS

The mean follow-up was 9.34±5.61 years. Severely distorted anatomies from Crowe I to Crowe IV were included, with a mean canal flare of 4.3 and a mean femoral antetorsion of 34°. The survival rates were stable at long-term (98.9% at 10 and 15 years): no aseptic loosening occurred. The mean postoperative HHS was 89.8±6.8 points. Ninety-nine percent of the stems showed bone ingrowth, from 6 months to the last available follow-up. Subsidence occurred in 18% of the cases (mean value: 2.5mm, range: 1-6mm) in the first month, with subsequent stabilization. A mild proximal stress shielding occurred in 28% of the THAs. Radiolucent lines were detected in the 8% of the cases. There was a postoperative loss of offset in 12% of the cases.

DISCUSSION

Conical stems in dysplastic hips achieved bony ingrowth at long-term outcome, even in complex anatomies. Subsidence, proximal stress shielding and imperfect offset restoration may occur with this implant.

LEVEL OF PROOF

IV; retrospective study.

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.

The Validation of Two-Dimensional and Three-Dimensional Radiographic Measurements of Host Bone Coverage in Total Hip Arthroplasty for Hip Dysplasia: A Comparison with Intra-Operative Measurements

Several methods have been introduced to measure the host bone coverage of the acetabular component after total hip arthroplasty (THA). The aims of this study were (1) to validate two-dimensional- and three-dimensional-based host bone coverage measurements by comparing intra-operative measurements, and (2) to determine the minimum host bone coverage for achieving stable cup fixation after THA in hip dysplasia. The clinical outcomes of each patient were evaluated during their final follow-up period using the Harris Hip score (HHS). The coverage of the host bone was analyzed by comparing 2D-based, 3D-based, and intraoperative assessments. The mean HHS was increased significantly from 60.84 ± 14.21 pre-operatively to 93.13 ± 4.59 (p < 0.0001). The host bone coverage ratio measured intraoperatively was 83.67 ± 3.40%, while the ratio measured by 3D CT reconstruction was 82.72 ± 3.59%. There was a strong positive correlation between the intra-operative host bone coverage and the 3D-based one (r = 0.826, p < 0.0001). It is recommended that 3D-based measurements are used to evaluate the host bone coverage after THA in patients with hip dysplasia. In addition, achieving a minimum host bone coverage of 75% is recommended for the attainment of stable cup fixation.

Clinical outcomes of proximal femoral reconstruction technique combined with THA in the treatment of high dislocation secondary to septic arthritis: a retrospective single-center study

PURPOSE

The aim of this retrospective study was to examine the clinical outcomes and complications of proximal femur reconstruction (PFR) combined with total hip arthroplasty (THA) in patients with high hip dislocation secondary to septic arthritis (SA).

METHODS

Between September 2016 to September 2021, we performed a series of 15 consecutive PFR combined with THA on patients with high dislocation of the hip secondary to SA, of these,12 hips were reviewed retrospectively, with a mean follow-up of 2.5 years (range, 1.5-6 years). The mean age of the patients at the time of surgery was 52 years (range, 40-70 years).

RESULTS

All patients were followed up. At 1-year postoperative follow-up, the median HHS increased from 32.50 preoperatively to 79.50 postoperatively. The median VAS decreased from 7 before surgery to 2 at 1 year after surgery. The median LLD reduced from 45 mm preoperatively to 8 mm at 1 year after surgery. The mean operative time 125 ± 15 min (range 103-195 min). Mean estimated blood loss was500 ± 105ml (range 450-870 ml). Mean hospital days 9.5 days (range 6-15 days). Two patients developed nerve injuries that improved after nutritional nerve treatment. One patient had recurrent postoperative dislocation and underwent reoperation, with no recurrence dislocation during the follow-up. There were no cases of prosthesis loosening during the follow-up period. One patient developed acute postoperative periprosthetic joint infection (PJI) that was treated with Debridement, Antibiotics and Implant Retention (DAIR) plus anti-infective therapy, with no recurrence during 2 years of follow-up.

CONCLUSION

This study indicates PFR combined with THA shows promise as a technique to manage high hip dislocation secondary to SA, improving early outcomes related to pain, function, and limb length discrepancy.

Total hip arthroplasty associated with transverse subtrochanteric shortening osteotomy and conical stem fixation in Crowe type IV hip dysplasia

PURPOSE

Total hip arthroplasty (THA) in high-dislocated hip dysplasia is a surgical challenge, presenting difficulties in the biomechanical reconstruction of the hip. The purpose of the present study is to analyze clinical and radiological outcomes of a series of patients with Crowe type IV hip dysplasia who underwent a THA with transverse subtrochanteric shortening osteotomy and conical stem fixation in our Hip surgery unit.

METHODS

This non-interventional retrospective study included all patients diagnosed with Crowe type IV hip dysplasia who underwent a THA using a subtrochanteric shortening osteotomy and uncemented conical stem fixation between January 1, 2008, and December 31, 2015. Demographic, clinical and radiologic data were analyzed, including Harris Hip Score and Oxford Hip Score.

RESULTS

Seventeen hips in 13 patients were included in the final analysis. All patients were women and mean age was 39 years (range 35-45). Mean follow-up was 5.6 years (range 1-8). Average length of the osteotomy was 3.4 cm (range 3-4.5) and mean lowering of the center of rotation was 5.67 cm (range 3.8-9.1). Mean time for bone union was 5.5 months. No nerve palsy or non-union was detected at the end of follow-up period.

CONCLUSION

The use of cementless conical stem fixation associated with a transverse subtrochanteric shortening osteotomy for treating Crowe type IV hip dysplasia permits to correct the rotational alterations of the femur and provides good stability of the osteotomy, with very low risk of nerve palsy and non-union rates.

The press-fit technique without screws and bone graft can be used as an alternative method in Crowe type II and III hip dysplasia

Background/aim

Developmental dysplasia of the hip (DDH) is the most common cause of secondary hip arthrosis. The primary purpose of this study was to assess the results of an oversized hemispherical cup via the press-fit technique used for Crowe type II and III DDH without screws and to determine if adequate medialization and initial stability of the acetabular component would allow us to avoid screw and graft use.

Materials and methods

Between February 2012 and May 2020, the current study analyzed 43 hips with Crowe type II and III DDH treated with a porous-coated cup by placing the press-fit technique or screw. The acetabular cup was fixed with the press-fit technique without additional screws in 27 hips and with screws in 16 hips. The inclusion criterion in this study was a minimum 2-year-period after the surgery.

Results

The mean duration of follow-up was 6.83 ± 2.67 years in the press-fit group and 6.21 ± 2.01 years in the screw group. The mean age of the patients was 47.96 ± 12.37 years in the press-fit group and 50.5 ± 12.37 years in the screw group. Measurements revealed that the hip center of rotation (HCR) was located more medially and superiorly postoperatively than preoperatively in both groups. The mean cup coverage in the screw group was 85.58% ± 7.51% (75.3%-97.2%), while it was less than 90.41% ± 6.15% (76.3%-98.2%) in the press-fit group (p = 0.038). No component was revised because of loosening, and all of the implants were radiologically stable within the observation period. No statistically significant differences were observed regarding the postoperative limp-length discrepancy between the groups (p = 0.496).

Conclusion

Press-fit implantation of a porous-coated acetabular component without screws can also be used as an alternative method for THA in Crowe type II and III DDH. The initial stability was obtained using the press-fit technique with a small cup positioned more medially and superiorly, which may allow the surgeon to avoid screw and graft use.

Effects of exercise therapy on the balance and gait after total hip arthroplasty: a systematic review and meta-analysis

The situation is such that there is a lack of research analyzing the effect of exercise therapy during the rehabilitation period of patients after total hip arthroplasty (THA). Therefore, the purpose of this systematic review and meta-analysis is to analyze the effects of exercise therapy on the balance and gait of patients after THA. The studies selected for this study were based on the PICO as follows: P (Patient)-patients after THA, I (Intervention)-exercise therapy, C (Comparison)-control and other therapy groups, O (Outcome)-balance and gait. Additional criteria for this study were study design (randomized controlled study), language (English), publication status (journal), and the year of publication were not limited. Eleven studies were included. The effects of exercise therapy on balance and gait in patients after THA were significantly different. Balance: standardized mean difference (SMD), 0.51; 95% confidence intervals (CI), 0.24-0.78; I2=22%. Gait: SMD, 0.39; 95% CI, 0.01-0.76; I2=66%. Rehabilitation specialists recommend that exercise therapy be included in rehabilitation programs to improve balance and gait in patients after THA. Further research is needed in the future, including more studies and a network meta-analysis that analyzes the effect size of each exercise therapy.

Postoperative hip center position is associated with gait symmetry in range of axial rotation in dysplasia patients after THA

Background

This study aimed to explore whether pre- or postoperative hip structures or surgical changes significantly influence hip range of motion (ROM) symmetry in patients with hip dysplasia during gait after total hip arthroplasty (THA) and provide possible surgical suggestions.

Methods

Fourteen patients with unilateral hip dysplasia underwent computed tomography before and after surgery to create three-dimensional hip models. Pre- and postoperative acetabular and femoral orientations, hip rotation centers (HRC), and femoral lengths were measured. Bilateral hip ROM during level walking after THA was quantified using dual fluoroscopy. The ROM symmetry in flexion-extension, adduction-abduction, and axial rotation was calculated using the symmetry index (SI). The relationship between SI and the above anatomical parameters and demographic characteristics was tested using Pearson's correlation and linear regression.

Results

The average SI values for flexion-extension, adduction-abduction, and axial rotation during gait were -0.29, -0.30, and -0.10, respectively. Significant correlations were detected mainly in the postoperative HRC position. A distally placed HRC was associated with increased SI values for adduction-abduction (R = -0.47, p = 0.045), while a medially placed HRC was associated with decreased SI values for axial rotation (R = 0.63, p = 0.007). A regression analysis indicated that horizontal HRC positions significantly determined axial rotational symmetry (R² = 0.40, p = 0.015). Normal axial rotation SI values were achieved with HRC between 17 mm medially and 16 mm laterally.

Conclusions

Postoperative HRC position was significantly correlated with gait symmetry in the frontal and transverse planes in patients with unilateral hip dysplasia after THA. Surgical reconstruction of the HRC to between 17 mm medially and 16 mm laterally may contribute to gait symmetry.

Total Hip Arthroplasty in Patients with Crowe III/IV Developmental Dysplasia of the Hip: Acetabular Morphology and Reconstruction Techniques

The severe anatomic deformities render acetabular reconstruction as one of the greatest challenges in total hip arthroplasty (THA) for patients with Crowe III/IV developmental dysplasia of the hip (DDH). Thorough understanding of acetabular morphology and bone defect is the basis of acetabular reconstruction techniques. Researchers have proposed either true acetabulum position reconstruction or high hip center (HHC) position reconstruction. The former can obtain the optimal hip biomechanics, including bulk femoral head autograft, acetabular medial wall displacement osteotomy, and acetabular component medialization, while the latter is relatively easy for hip reduction, as it can avoid neurovascular lesions and obtain more bone coverage; however, it cannot achieve good hip biomechanics. Both techniques have their own advantages and disadvantages. Although there is no consensus on which approach is better, most researchers suggest the true acetabulum position reconstruction. Based on the various acetabular deformities in DDH patients, evaluation of acetabular morphology, bone defect, and bone stock using the 3D image and acetabular component simulation techniques, as well as the soft tissue tension around the hip joint, individualized acetabular reconstruction plans can be formulated and appropriate techniques can be selected to acquire desired clinical outcomes.

Total Hip Arthroplasty in Patients Aged 40 to 60 years old: A Population-Based Study

INTRODUCTION

Contemporary total hip arthroplasty (THA) has resolved many implant longevity concerns in younger patients. Patients in their fourth and fifth decades of life are projected to be the fastest growing demographic of THA patients. We aimed to assess this demographic to evaluate the: 1) rate of THA over time; 2) cumulative incidence of revision; and 3) identify risk factors for revision.

METHODS

A retrospective population-based study of patients between 40 and 60 years old undergoing primary THA was conducted using administrative data from a large clinical data repository. A total of 28,414 patients were included for analysis with a mean age of 53 years (range, 40-60 years) and median follow up of 9 years (range, 0-17 years). Linear regressions were used to assess annual rates of THA in this cohort over time. Kaplan-Meier analysis was used to determine cumulative incidence of revision. Multivariate cox proportional hazards models were used to determine association of variables with revision risk.

RESULTS

The annual rate of THA in our population increased by 60.7% over the study period (P <0.0001). Cumulative incidence of revision was 2.9% at 5-years and 4.8% at 10-years. Younger age, women, non-osteoarthritis diagnosis, medical complications, and annual surgeon volume < 60 THA were associated with increased revision risk.

CONCLUSION

Demand for THA continues to dramatically increase in this cohort. Risk of revision was low but multiple risk factors were identified. Future studies will help delineate the effect of these variables on revision risk and assess implant survivorship beyond 10 years.

Acetabular Diameter Assessment and Three-Dimensional Simulation for Acetabular Reconstruction in Dysplastic Hips

BACKGROUND

This study aimed to investigate the relationship between acetabular width, three-dimensional (3D) simulation, and surgical results in total hip arthroplasty patients who have developmental dysplasia of the hip (DDH).

METHODS

This retrospective study included 216 DDH cases. Inner and outer acetabular width (OAW) was measured at the plane passing through the center of acetabular fossa. 3D simulation and 2D standard templating were performed. The actual cup size and the use of augments during surgery were recorded. Association among the indices and their distribution in different types of DDH were analyzed.

RESULTS

A difference of 13 to 14 millimeters (mm) was found between the inner acetabular width and actual cup size used in type II, III, and IV cases, while the difference was 0.2 to 3.6 mm for OAW. The accuracy of 2D templating and 3D simulation in predicting cup size was comparable in Crowe type I (86.5 versus 76%, P = .075), type II (72.7 versus 51.5%, P = .127), and type III (93.3 versus 66.7%, P = .169). The 3D simulation was significantly more accurate in Crowe type IV (89.1% versus 60.9%, P = .001). Augments and bone grafts were significantly more commonly used in type II (25%) than in the other types (0 to 6.5%).

CONCLUSION

OAW more accurately predicted actual cup size than inner acetabular width. The supero-lateral acetabular bone defects in type II cases require additional attention. Compared with 2D templating, 3D simulation is more accurate in predicting actual cup size in dysplastic hips with severe deformity and may be recommended in these selected cases, especially for Crowe IV patients.

Predictors of Total Hip Arthroplasty Following Pediatric Surgical Treatment of Developmental Hip Dysplasia at 20-Year Follow-Up

Long-term outcomes of surgical treatment for pediatric developmental dysplasia of the hip (DDH) are not well defined. The purpose of this study was to report long-term radiographic and clinical outcomes, survivorship free of total hip arthroplasty (THA), and predictors of subsequent THA following childhood treatment of DDH. This study was a single-institution retrospective review of hips treated for DDH with closed or open reduction at a minimum 10-year follow-up. 107 patients (119 hips) were included with a mean patient age of 3.3 years at childhood treatment. At mean 30.5 years follow-up, 24 hips had undergone THA (20%). Mean patient age at time of THA was 33.5 years. None of the hips treated with closed reduction alone required THA, whereas 8 hips treated with open reduction (25%) underwent THA. Hips with patient age > 4 years at the time of treatment had lower survivorship at 35 years follow-up (50% vs. 85%; p < 0.001). Additionally, femoral osteotomy (OR 2.0, p < 0.001), and previous treatment elsewhere (27% vs. 16%; p < 0.01) were associated with subsequent THA. Early referral and appropriate intervention may prove important, as age and prior treatment were predictive of subsequent THA.

Direct anterior versus posteriorlateral approachs for clinical outcomes after total hip arthroplasty in the treatment of severe DDH

BACKGROUND

The total hip arthroplasty (THA) has gained popularity in in the treatment of severe developmental dysplasia of the hip (DDH). the posterior lateral approach (PLA) has good clinical efficacy and has been confirmed by the majority clinicians. Nevertheless, controversy exists regarding longer-term benefits of the direct anterior approach (DAA). The objective of this study was to investigate the clinical efficacy and placement of S-ROM prosthesis in the treatment of severe DDH by The total hip arthroplasty (THA) with different surgical approaches.

METHODS

A retrospective analysis was performed on 42 patients with severe DDH admitted to our hospital from August 2015 to February 2022, who were treated with S-ROM prosthesis for total hip arthroplasty and subtrochanteric osteotomy of the femur. They were divided into DAA group and PLA group according to different surgical approaches. Perioperative indicators and imaging data were collected.

RESULTS

The surgery time, intraoperative blood loss, and creatine kinase difference in DAA group and PLA group was without a statistically significant difference (P > 0.05). The postoperative length of hospitalization was shorter in the DAA group than in the PLA group (6.50 ± 3.15 vs 9.18 ± 4.93, P = 0.045). The acetabular abduction angles、the acetabular anteversion angles, the safe area ratio, The difference of femoral eccentricity, and the vertical difference of rotation center in DAA group and PLA group, there was no statistical significance (P > 0.05). Statistically significant differences were detected the horizontal difference of rotation center (P = 0.044).

CONCLUSIONS

Total hip arthroplasty with S-ROM prosthesis is a feasible procedure for severe dysplastic DDH. The clinical efficacy and prosthesis placement parameters of DAA approach are advantage to those of PLA approach.

Minimum 10-Year Follow-Up of Total Hip Arthroplasty With a Collarless Triple-Tapered Polished Cemented Stem With Line-to-Line Implantation Using a Direct Anterior Approach

BACKGROUND

The Trilliance stem (B. Braun-Aesculap, Tuttlingen, Germany), a novel collarless triple-tapered polished stem, was introduced in 2009. The aim of this study is to evaluate the long-term clinical and radiological results of the Trilliance stem with line-to-line implantation in primary total hip arthroplasty using a direct anterior approach.

METHODS

A consecutive retrospective series of 130 patients (151 hips) who underwent total hip arthroplasty between February 2009 and August 2011 were evaluated for a minimum of 10 years. Of these, 87.4% had a diagnosis of secondary osteoarthritis based on developmental hip dysplasia. Clinical and radiological results, complications were evaluated and survival analysis was performed.

RESULTS

The mean follow-up was 10.7 years (range, 10.0-12.1). Thirteen hips (13 patients, 6.8%) were lost to follow-up. Adequate cementation (Barrack grade A) was achieved in 136 hips (93.8%) 1 week post-operatively. Nearly all (144 hips, 99.3%) had been inserted within the range of 3°. No significant differences were identified between high- (≥30 procedures/year) and low- (<30 procedures/year) volume surgeons. The Kaplan-Meier survival analysis with revision of the femoral component for aseptic loosening, revision of the femoral component for any reason and revision of either component for any reason as the end points, cumulative survivorship was 100.0%, 97.6% (95% confidence interval (CI) 95.4-100.0) and 96.5% (95% CI 93.8-99.3) at 10 years, respectively.

CONCLUSION

The Trilliance stem with line-to-line implantation using a direct anterior approach has an excellent clinical and radiological outcome at a minimum of 10 years' follow-up.

LEVEL OF EVIDENCE

Level IV, Retrospective cohort study.