Total hip arthroplasty for adult hip dysplasia

HIPPO artificial intelligence: Correlating automated radiographic femoroacetabular measurements with patient-reported outcomes in developmental hip dysplasia

BACKGROUND

Hip dysplasia (HD) is characterized by insufficient acetabular coverage of the femoral head, leading to a predisposition for osteoarthritis. While radiographic measurements such as the lateral center edge angle (LCEA) and Tönnis angle are essential in evaluating HD severity, patient-reported outcome measures (PROMs) offer insights into the subjective health impact on patients.

AIM

To investigate the correlations between machine-learning automated and manual radiographic measurements of HD and PROMs with the hypothesis that artificial intelligence (AI)-generated HD measurements indicating less severe dysplasia correlate with better PROMs.

METHODS

Retrospective study evaluating 256 hips from 130 HD patients from a hip preservation clinic database. Manual and AI-derived radiographic measurements were collected and PROMs such as the Harris hip score (HHS), international hip outcome tool (iHOT-12), short form (SF) 12 (SF-12), and Visual Analogue Scale of the European Quality of Life Group survey were correlated using Spearman's rank-order correlation.

RESULTS

The median patient age was 28.6 years (range 15.7-62.3 years) with 82.3% of patients being women and 17.7% being men. The median interpretation time for manual readers and AI ranged between 4-12 minutes per patient and 31 seconds, respectively. Manual measurements exhibited weak correlations with HHS, including LCEA (r = 0.18) and Tönnis angle (r = -0.24). AI-derived metrics showed similar weak correlations, with the most significant being Caput-Collum-Diaphyseal (CCD) with iHOT-12 at r = -0.25 (P = 0.042) and CCD with SF-12 at r = 0.25 (P = 0.048). Other measured correlations were not significant (P > 0.05).

CONCLUSION

This study suggests AI can aid in HD assessment, but weak PROM correlations highlight their continued importance in predicting subjective health and outcomes, complementing AI-derived measurements in HD management.

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.

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.

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.

The Wagner Cone Stem for Atypical Femoral Anatomy in Total Hip Arthroplasty: A Report of 320 Cases with Minimum 5-Year Follow-up

BACKGROUND

The Wagner Cone Prosthesis was designed to address complex femoral deformities during total hip arthroplasty (THA), but its mid-term component survivorship and functional outcomes remain undetermined. The objectives of this study were to determine the implant survivorship, patient satisfaction, functional outcomes, osseointegration as seen radiographically, implant subsidence, and complications of THA using the Wagner Cone Prosthesis stem at intermediate-term follow-up.

METHODS

This study involved 302 patients with proximal femoral deformities, including developmental hip dysplasia and Legg-Calvé-Perthes disease, who underwent a total of 320 primary THAs using the Wagner Cone Prosthesis. The average age at the time of surgery was 49.4 ± 14.5 years (range, 18.8 to 85.6 years). Patient satisfaction was recorded using a self-administered questionnaire assessing satisfaction in 4 domains. The University of California at Los Angeles (UCLA) activity score, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Oxford Hip Score (OHS), the Forgotten Joint Score (FJS), radiographic outcomes, and complications were recorded. The mean follow-up time was 10.1 years (range, 5.2 to 15.5 years).

RESULTS

Survivorship of the Wagner Cone Prosthesis was 98.7% (95% confidence interval [CI]: 97.2% to 100%) with stem revision as the end point and 95.8% (95% CI: 93.5% to 98.2%) with reoperation for any reason as the end point at 10 years postoperatively. In total, 3 stems were revised: 2 for infection and 1 for chronic hip dislocation. The median patient satisfaction score was 95 (interquartile range [IQR], 80 to 100), median UCLA score was 6 (IQR, 6 to 7), median WOMAC score was 18 (IQR, 16 to 22), median OHS was 40 (IQR, 36 to 47), and median FJS was 80 (IQR, 76 to 88) at the time of final follow-up. All Wagner Cone stems that were not revised showed radiographic evidence of osseointegration, with a mean stem subsidence of 0.9 ± 0.8 mm at the most recent follow-up.

CONCLUSIONS

The use of the Wagner Cone Prosthesis stem in patients with complex femoral anatomy undergoing primary THA is associated with excellent component survivorship, high levels of patient satisfaction, good functional outcomes, and reliable osseointegration with minimal stem subsidence as seen on radiographs at intermediate-term follow-up.

LEVEL OF EVIDENCE

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

Midterm Results of Severe Hip Dysplasia after Using a Cementless Acetabular Component with Bulk Bone Graft in Total Hip Arthroplasty: A Minimum Five-Year Follow-Up Study

In patients with severe hip dysplasia, total hip arthroplasty (THA) using bulk bone graft (BBG) enhances anatomic cup positioning and provides early structural support. This study assesses the mid-term outcomes of THA with BBG in patients with over 50% graft bone coverage. Among 1951 patients who underwent THA between 2003 and 2007, 183 had BBG. After excluding early dropouts and infections, 151 patients remained. They were classified into uncovered (<50% coverage, 79 patients) and covered (>50% coverage, 72 patients) groups. The efficacy of cup fixation was compared between these groups. After ten years, the survival rate for not needing THA revision was 98% in the uncovered group and 100% in the covered group, while the rate for radiographic stability was 93% versus 99%, respectively. Although the cutoff value for the uncovered portion could not be clarified in this study, the mid-term results for 50% to approximately 70% uncovered were comparable to those for 50% or lesser, which have previously been expected to perform well. Recently, biomechanically advantageous bone grafting techniques have been identified, and based on the results of this study, it may be possible to expand the indications for THA with bone grafting for developmental dysplasia of the hip.

Robotic Arm-Assisted System Improved Accuracy of Cup Position and Orientation in Cementless Total Hip Arthroplasty for Dysplastic Hips: A Comparison Among Groups With Manual Placement, Computed Tomography-Based Navigation, and Robotic Surgery

Background

Accurate cup placement in total hip arthroplasty (THA) for patients with dysplasia is challenging due to the distinctive bone deformities. This study aimed to compare the accuracy of cup placement position and orientation across robotic arm-assisted systems (R-THA), computed tomography-based navigation (N-THA), and manual procedure (M-THA) in THA for osteoarthritis secondary to dysplasia.

Methods

A total of 167 patients (197 hips), including 88 R-THAs, 45 N-THAs, and 46 M-THAs, were analyzed. Propensity score matching was performed to align the patient backgrounds. Horizontal and vertical centers of rotation were measured for cup position, whereas radiographic inclination and anteversion were measured for cup orientation. The proportion of cases with cup placement within 3 mm and 5° from the target was compared.

Results

R-THA had a significantly higher percentage of cup placement within 3 mm of the target compared to N-THA (78% vs 49%; P = .0041) and M-THA (78% vs 53%; P = .013). Similarly, R-THA was significantly more successful in placing the cup within 5° of the target compared to N-THA (84% vs 58%; P = .0049) and M-THA (91% vs 20%; P < .0001). Moreover, N-THA was significantly better at placing the cup within 5° of the target compared to M-THA (62% vs 14%; P < .0001), whereas there was no significant difference in the percentage of cup placement within 3 mm of the target (51% vs 51%; P = 1.0).

Conclusions

Robotic arm-assisted system and computed tomography-based navigation improved accuracy in cup orientation compared to the manual procedure. Additionally, the robotic arm-assisted system further improved cup position accuracy.

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.

[Translated article] Total hip arthroplasty with shelf acetabuloplasty in dysplastic coxarthrosis, mean follow-up of 7 years

INTRODUCTION

Developmental dysplasia of the hip is the cause of approximately one third of secondary coxarthrosis. Anatomy alterations make it difficult to place a total hip prosthesis in its anatomical position and for it to be stable in the long term; there are several techniques to achieve this goal. In the present work, we used autograft of the femoral head (shelf graft or reinforced roof), to improve the coverage of the acetabular component with favourable results.

MATERIALS AND METHODS

Sixteen cases were included in 14 patients with a diagnosis of developmental dysplasia of the hip (13 women and one man), the mean age was 44.3 years (range 35-68 years), with a mean follow-up of 7 years (range 1-15 years). All the cases were evaluated clinically and radiographically, to demonstrate the osseointegration of the graft and the functional results in the medium term.

RESULTS

All the acetabular components were placed in anatomical position (Ranawat technique), the mean percentage of host bone coverage was 54.53% (range 43.28-79.05%), obtaining additional coverage with the bone graft of 45.13%. Osseointegration of the graft of 100% at 12 weeks, resorption of the graft from the sixth month, stabilising in the third postoperative year. Only one case of dislocation is reported, no cases of infection, loosening, heterotopic ossification or revision.

CONCLUSION

This procedure has shown good functional results in the medium term with 100% osseointegration, despite cases of severe bone resorption of the graft that does not compromise the stability of the prosthesis.

Total hip arthroplasty with shelf acetabuloplasty in dysplastic coxarthrosis, mean follow-up of 7 years

Developmental dysplasia of the hip is the cause of approximately one third of secondary coxarthrosis. Anatomy alterations make it difficult to place a total hip prosthesis in its anatomical position and for it to be stable in the long term; there are several techniques to achieve this goal. In the present work, we used autograft of the femoral head (shelf graft or reinforced roof), to improve the coverage of the acetabular component with favorable results.

MATERIALS AD METHODS

Sixteen cases were included in 14 patients with a diagnosis of developmental dysplasia of the hip (13 women and one man), the mean age was 44.3 years (range 35-68 years), with a mean follow-up of 7 years (range 1-15 years). All the cases were evaluated clinically and radiographically, to demonstrate the osseointegration of the graft and the functional results in the medium term.

RESULTS

All the acetabular components were placed in anatomical position (Ranawat technique), the mean percentage of host bone coverage was 54.53% (range 43.28-79.05%), obtaining additional coverage with the bone graft of 45.13%. Osseointegration of the graft of 100% at 12 weeks, resorption of the graft from the sixth month, stabilizing in the third postoperative year. Only one case of dislocation is reported, no cases of infection, loosening, heterotopic ossification or revision.

CONCLUSION

This procedure has shown good functional results in the medium term with 100% osseointegration, despite cases of severe bone resorption of the graft that does not compromise the stability of the prosthesis.

Accuracy of portable navigation during THA in patients with severe developmental dysplasia of hip

INTRODUCTION

Correct cup placement in total hip arthroplasty (THA) for patients with developmental dysplasia of the hip (DDH) is considerably difficult. This study aimed to analyze the orientation accuracy of cup insertion during THA using a portable navigation system in patients with DDH.

MATERIALS AND METHODS

In this retrospective cohort study, we analyzed data from 64 patients who underwent THA using infrared stereo camera-matching portable navigation. Patients underwent THA via the anterolateral approach in the lateral decubitus position. Navigation records for intraoperative cup angles, postoperative cup angles measured on computed tomography (CT) images, and cup angle measurement differences were measured and compared between patients with non-DDH/mild DDH and severe DDH. Furthermore, the predictive factors for outliers of accurate acetabular cup placement were analyzed.

RESULTS

The average measurement absolute abduction differences (postoperative CT-navigation record) were 3.9 ± 3.5° (severe DDH) and 3.3 ± 2.6° (non-DDH/ mild DDH), and the anteversion differences were 4.7 ± 3.4° (severe DDH) and 2.3 ± 2.1° (non-DDH/ mild DDH). The anteversion difference was different between the two groups. Multivariate analysis showed that the navigation difference (absolute difference in anteversion between postoperative CT and navigation records of > 5°) was significantly associated with severe DDH (odds ratio [OR]: 3.3; p = 0.049, 95% confidence interval [CI]: 1.0-11.1) and posterior pelvic tilt (OR: 1.1; p = 0.042, 95% CI: 1.0-1.27).

CONCLUSIONS

In patients with severe DDH, it is important to pay close attention during THA using portable navigation. However, the average difference was < 5º even in patients with severe DDH, and the accuracy may be acceptable in a clinical setting when the cost is considered.

Robotic arm-assisted total hip arthroplasty via a minimally invasive anterolateral approach in the supine position improves the precision of cup placement in patients with developmental dysplasia of the hip

BACKGROUND

This study evaluated the accuracy of the cup alignment angles and spatial cup positioning on computed tomography (CT) images in patients with osteoarthritis secondary to developmental dysplasia of the hip (DDH) who underwent total hip arthroplasty (THA) using a minimally invasive technique via an anterolateral approach in the supine position according to whether a robotic arm-assisted system or a CT-based navigation system was used.

METHODS

We reviewed 60 robotic arm-assisted (RA)-THA cases and 174 navigation-assisted (NA)-THA cases. After propensity score matching, there were 52 hips in each group. Postoperative cup alignment angles and position were assessed by superimposition of a three-dimensional cup template onto the actual implanted cup using postoperative CT images with pelvic coordinates matching the preoperative planning.

RESULTS

The mean absolute error of the inclination angle and the anteversion angle between the preoperative planning and the postoperative measurement was significantly smaller in the RA-THA group (inclination, 1.1° ± 0.9; anteversion, 1.3° ± 1.0) than in the NA-THA group (inclination, 2.2° ± 1.5; anteversion, 3.3° ± 2.5). For acetabular cup positioning, the mean discrepancy between the preoperative planning and the postoperative measurement was 1.3 ± 1.3 mm on the transverse axis, 2.0 ± 2.0 mm on the longitudinal axis, and 1.3 ± 1.7 mm on the sagittal axis in the RA-THA group and 1.6 ± 1.4 mm, 2.6 ± 2.3 mm, and 1.8 ± 1.3 mm, respectively, in the NA-THA group. High precision of cup positioning was observed in both groups with no statistically significant difference.

CONCLUSION

Robotic arm-assisted THA using a minimally invasive technique via an anterolateral approach in the supine position allows accurate cup placement in patients with DDH.

Subtrochanteric Osteotomy in Direct Anterior Approach Total Hip Arthroplasty for Crowe IV Dysplasia-Surgical Technique and Literature Review

For Crowe IV dysplasia, the clinical efficacy and surgical technique of subtrochanteric osteotomy (SO) within the direct anterior approach total hip arthroplasty (DAA-THA) was a subject of debate. This study aimed to describe the surgical technique and clinical outcomes in 11 cases of SO in DAA-THA and to summarize the relevant literature on this topic. Between June 2016 and June 2023, we retrospectively evaluated patients diagnosed with Crowe IV hip dysplasia at our institution. Criteria identified 11 patients who underwent SO during DAA-THA. Comprehensive data encompassing demographic information, radiological data, prosthetic implant type, and surgical intricacies were collected. In addition, an exhaustive review of existing case series literature was undertaken utilizing the PubMed databases. There were no revisions, deaths, dislocations, or infections. One hip (9.09%) had an intraoperative proximal split fracture, two hips (18.2%) had lower limb deep vein thrombosis, and one hip (9.09%) had symptoms of femoral nerve injury. Radiological data showed improved bilateral femoral offset, leg length discrepancy, and anatomical acetabular. During the mean follow-up of 2.18(1.06-2.46) years, patients demonstrated enhanced functional outcomes, with average changes of 25.2 in the Harris hip score and 47 in the WOMAC score. Reviewing the literature, most studies have favored S-ROM prostheses and transverse osteotomy techniques. Intraoperative fractures were notably frequent, with rates peaking at 25%. Nonunion and nerve injury were secondary common complications. SO via DAA-THA may offer satisfactory clinical and radiographic outcomes, but the literature review underscores the need for heightened awareness of intraoperative fracture risk. Proximal detachment of the vastus intermedius plays a pivotal role in SO exposure through the DAA.

Improved Functional Outcomes of Combined Hip Arthroscopy and Periacetabular Osteotomy at Minimum 2-Year Follow-Up

PURPOSE

To evaluate patient-reported outcomes (PROs) and survivorship at minimum 2-year follow-up after combined hip arthroscopy and periacetabular osteotomy (PAO) performed in the setting of a single anesthetic event.

METHODS

Patients who underwent combined hip arthroscopy (M.J.P.) and PAO (J.M.M.) between January 2017 and June 2020 were identified. Preoperative and minimum 2-year postoperative PROs including Hip Outcome Score-Activities of Daily Living (HOS-ADL), HOS-Sport, modified Harris Hip Score (mHHS), Western Ontario and McMaster Universities Osteoarthritis Index, 12-Item Short Form Survey Mental Component Scores (SF-12 MCS), and 12-Item Short Form Survey Physical Component Score were collected and compared in addition to revision rate, conversion to total hip arthroplasty (THA), and patient satisfaction.

RESULTS

Twenty-four of 29 patients (83%) eligible for the study were available for 2-year minimum follow-up with a median follow-up time of 2.5 years (range, 2.0-5.0). There were 19 females and 5 males with mean age of 31 ± 12 years. Mean preoperative lateral center edge angle was 20° ± 5° and alpha angle was 71° ± 11°. One patient underwent reoperation for removal of a symptomatic iliac crest screw at 11.7 months after operation. Two patients, a 33-year-old woman and a 37-year-old man, were converted to THA at 2.6 and 1.3 years, respectively, following the combined procedure. Both patients had a Tönnis grade of 1 on radiographs, as well as bipolar Outerbridge grade III/IV defects requiring microfracture of the acetabulum. For patients who did not convert to THA (n = 22), there was significant improvement from before to after surgery for all scores (P < .05) except SF-12 MCS. The minimal clinically significant difference and patient-acceptable symptom state rates for HOS-ADL, HOS-Sport, and mHHS were 72%, 82%, 86%, and 95%, 91%, and 95%, respectively. Median patient satisfaction was 10 (range, 4 to 10).

CONCLUSIONS

Single-stage combined hip arthroscopy with periacetabular osteotomy for patients with symptomatic hip dysplasia results in improvement in PROs and arthroplasty free survivorship of 92% at median 2.5 year follow-up.

LEVEL OF EVIDENCE

Level IV, case series.

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.

Intraoperative Neurophysiological Monitoring in Total Hip Arthroplasty for Crowe Types 3 and 4 Hips

Background

Crowe types 3 and 4 dysplastic hips usually need total hip arthroplasty (THA) with femoral shortening osteotomy (FSO) to facilitate reduction, equalize limb length, and decrease the traction stress in nerves. The frequency of peripheral nerve palsy after primary THA has been reported to range from 0.08% to 3.7%. Apart from direct trauma to the nerve, the excessive extension of the extremity is also reported as a common cause of nerve damage. The current study aimed to evaluate the outcomes of intraoperative neurophysiological monitoring (IONM) in THA for Crowe types 3 and 4 hips.

Methods

The data of patients who underwent primary THA with IONM were retrospectively reviewed using our medical records. Patients with Crowe types 3 and 4 dysplastic hips were included in the study. Motor-evoked potentials and somatosensory-evoked potentials were assessed intraoperatively. Preoperative dislocation height and postoperative trochanter minor differences were measured using preoperative and postoperative radiographs.

Results

Twenty-three hips of 19 patients (4 bilateral THAs) with a mean age of 45 years participated in the study. Ten hips (43%) were classified as Crowe type 4, whereas 13 hips (57%) were Crowe type 3. The mean preoperative dislocation height was 41.6 mm (range, 15-100 mm). Postoperatively, only 6 patients had a difference between trochanter minor levels with a mean of 8.5 mm (range, 3-17 mm). Three patients underwent a subtrochanteric FSO to achieve reduction. Postoperatively, no patient had any motor and sensory nerve dysfunction.

Conclusions

According to the results acquired from this study, no nerve palsy was observed after THA for Crowe types 3 and 4 hips, and subtrochanteric FSO was not performed in all Crowe type 3 hips and 70% of Crowe type 4 hips with the aid of IONM.

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.

Developmental Dysplasia of the Hip (DDH): Etiology, Diagnosis, and Management

Developmental dysplasia of the hip (DDH) is a complex disorder that refers to different hip problems, ranging from neonatal instability to acetabular or femoral dysplasia, hip subluxation, and hip dislocation. It may result in structural modifications, which may lead to early coxarthrosis. Despite identifying the risk factors, the exact aetiology and pathophysiology are still unclear. Neonatal screening, along with physical examination and ultrasound, is critical for the early diagnosis of DDH to prevent the occurrence of early coxarthrosis. This review summarizes the currently practised strategies for the detection and treatment of DDH, focusing particularly on current practices for managing residual acetabular dysplasia (AD). AD may persist even after a successful hip reduction. Pelvic osteotomy is required in cases of persistent AD. It could also be undertaken simultaneously with an open hip reduction. Evaluation of the residual dysplasia (RD) of the hip and its management is still a highly active area of discussion. Recent research has opened the door to discussion on this issue and suggested treatment options for AD. But there is still room for more research to assist in managing AD.

Three-dimensional femur morphology analysis for the optimal location of subtrochanteric osteotomy with an implanted Wagner cone stem in total hip arthroplasty for Crowe type IV developmental dysplasia of the hip

BACKGROUND

This study aimed to accurately evaluate the matching of proximal and distal femoral segments and fitting of the femur-femoral stem in patients with Crowe type IV developmental dysplasia of the hip (DDH) who have undergone subtrochanteric osteotomy at different locations with an implanted Wagner cone stem to improve the rate of the bone union at the osteotomy site.

METHODS

Three-dimensional femur morphology of 40 patients with Crowe type IV DDH was evaluated at each cross-section to determine the femoral cortical bone area. This study focused on five osteotomy lengths (2.5, 3, 3.5, 4, and 4.5 cm). The overlapped area between the proximal and distal cortical bone segments was defined as the contact area (S, mm²), and the contact area to distal cortical bone area ratio was defined as the coincidence rate (R). Three indicators were used to evaluate the matching and fitting of the osteotomy sites with the implanted Wagner cone stems: (1) higher S and R between the proximal and distal segments; (2) the effective fixation length of the femoral stem at the distal segments being at least 1.5 cm; and (3) osteotomy did not involve the isthmus.

RESULTS

In all groups, S significantly decreased in the two proximal levels above the 0.5 cm level below the lesser trochanter (LT) compared with those below this level. In comparison, at osteotomy lengths from 2.5 to 4 cm, R significantly decreased in the three proximal levels. The optimal osteotomy levels ranged from 1.5 and 2.5 cm below the LT for an appropriately sized stem.

CONCLUSIONS

Subtrochanteric osteotomy at the optimal level not only ensures fitting of the femur-femoral stem but also meets the requirements of a higher S and R to ensure adequate reduction and stabilization at the osteotomy site, which may contribute to the bone union. Although the optimal osteotomy level varies with the size of the femoral stem and the length of the subtrochanteric osteotomy, the optimal osteotomy levels for an appropriately sized Wagner cone femoral stem implantation range from 1.5 to 2.5 cm below the LT.

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.

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

OBJECTIVE

Performing subtrochanteric osteotomy with cemented components in patients with Crowe IV developmental dysplasia of the hip (DDH) is technically challenging and not widely reported. This study aimed to evaluate the mid-term outcomes of cemented stem total hip arthroplasty (THA) with subtrochanteric femoral shortening and transverse derotational osteotomy in patients with Crowe IV DDH.

METHODS

Data collected from patients with Crowe IV DDH who underwent cemented stem THA with subtrochanteric femoral shortening and transverse derotational osteotomy between 2010 and 2018 were retrospectively evaluated. The cemented Lubinus SP II femoral component and the cementless CombiCup acetabular component were used together in all cases. These data, including Harris hip scores, limb length discrepancy (LLD), severity of limp, Trendelenburg test, bone union, length of the resected femur, limb lengthening, level of the osteotomy site, and length bridging the osteotomy site, as well as complications, were analyzed. A paired Student t-test was used to analyze continuous variables, categorical data were compared using Fisher's exact probability test, and correlation analysis was performed using Spearman's rank correlation coefficient.

RESULTS

Among 14 included patients (10 females and four males), the mean age was 60.4 years (range, 47-73). The mean follow-up period was 49.1 months, and no patient was lost to follow-up. The mean Harris hip score improved from 40.7 to 87.7. The mean LLD decreased from 52 to 12.7 mm. The mean length of the excised femoral segment was 38.4 mm, and the mean length of limb lengthening was 27.1 mm. The mean distance between the osteotomy site and the lesser trochanter was 21.1 mm after surgery. The mean length of the femoral stem bridging the osteotomy site was 97.6 mm. Finally, the mean osteotomy union time was 10.6 months. No statistically significant correlation was found between the osteotomy union time and these factors. No neurological deficits were noted. Delayed union was observed in one patient, and postoperative dislocation was observed in two patients. Cement leakage into the osteotomy gap was observed in one patient, however, no revisions were required, and no signs of loosening or migration were observed.

CONCLUSIONS

Cemented stem THA combined with subtrochanteric femoral shortening and transverse derotational osteotomy is safe and effective in treating patients with Crowe IV DDH. Rather than leading to nonunion, cement leakage may negatively affect bone healing.

A propensity score-matched comparison between Mako robotic arm-assisted system and conventional technique in total hip arthroplasty for patients with osteoarthritis secondary to developmental dysplasia of the hip

BACKGROUND

The clinical effectiveness of robotic arm-assisted systems remains unclear for total hip arthroplasty (THA) in patients suffering from osteoarthritis secondary to developmental dysplasia of the hip (DDH).

METHODS

Patients with DDH who underwent primary THA were included in this study. We conducted a propensity score-matched comparison between THAs using a robotic arm-assisted system (Mako group) versus those using the manual procedure (manual group) to compare the absolute differences in cup placement angles measured using postoperative computed tomography and those planned preoperatively.

RESULTS

A total of 217 patients with osteoarthritis due to DDH met the inclusion criteria. Eighty-four patients were matched as the Mako group and 84 as the manual group. The differences were smaller in the Mako group than the manual group in terms of both inclination and anteversion angles (1.1 ± 1.0 versus 4.2 ± 3.1, respectively; 95% CI, 2.4 to 3.8; p < 0.0001, and 1.2 ± 1.1 versus 5.8 ± 4.0, respectively; 95% CI, 3.7 to 5.5; p < 0.0001).

CONCLUSIONS

The robotic arm-assisted system may provide more accurate cup placement in THA for DDH.

Impaction Grafting Is Sufficient to Address Acetabular Deficiency During Total Hip Arthroplasty of Most Dysplastic Hips With Over 30% Bone Defect

BACKGROUND

Addressing acetabular deficiency during arthroplasty of dysplastic hips is challenging. We assessed outcomes of a protocol for choosing either impaction or structural graft for this purpose.

METHODS

This retrospective study included 59 patients (71 hips) with a dysplastic hip and over 30% uncoverage that underwent cementless total hip arthroplasty. Morselized impaction grafting was performed for hips where initial stability of the acetabular cup was achieved. In others, a shelf graft was inserted before implantation of the acetabular cup. Outcomes were assessed at a minimum follow-up of 4 years.

RESULTS

Fifty-seven (80.3%) hips underwent impaction grafting and 14 (19.7%) received a structural graft. Mean age at surgery was 48.1 ± 13.5 (18-68) years for impaction and 48.6 ± 14 (24-70) years for shelf grafts. Mean increase in Harris Hip Score was 51.5 ± 9.3 and 50 ± 11.2 for the impaction and structural groups, respectively, at a mean follow-up of 92 (49-136) months (P = .6). Heterotopic ossification occurred in 16 patients in the impaction group vs none in the structural group (P = .004). Radiologically, mean percentages of cup coverage provided by the graft were 47.8 ± 10.9% and 48.9 ± 13.3% in the impaction and structural groups, respectively (P = .75). All but one of shelf grafts united to host bone and all impaction grafts incorporated. There was one case of cup loosening in the structural graft group.

CONCLUSION

Most dysplastic acetabula with over 30% defect can be addressed using a cementless cup and impaction grafting, with good results in the midterm. In about 20% of cases, initial press-fit is not attainable and structural support-like shelf graft becomes necessary.

LEVEL OF EVIDENCE

IV.

Early Emergent and Progressive Aberrant Subchondral Bone Remodeling Coupled with Aggravated Cartilage Degeneration in Developmental Dysplasia of the Hip

OBJECTIVE

Developmental dysplasia of the hip (DDH) is the most common skeletal development in children and could result in secondary osteoarthritis. This study aims to clarify the alternations of subchondral trabecular bone remodeling and microstructural properties during the development of DDH, and the potential influence of these alternations on the overlying cartilage degeneration and DDH progression.

DESIGN

Traditional straight-leg swaddling method was adopted to establish DDH model in newborn Sprague Dawley rats. Hip joint specimens from normal or DDH rats were used. Typical features of DDH in radiological examination were observed by x-ray analysis. Micro-computed tomography analysis was applied to evaluate the microstructural properties of subchondral bone at postnatal weeks 2, 4, and 6. Histological and immunohistochemical analyses were adopted to appraise subchondral bone remodeling activity and cartilage degeneration. The associations among subchondral bone, articular cartilage, and DDH severity were analyzed via multiple linear regression analysis.

RESULTS

Compared with control group, the subchondral bone in DDH group displayed a gradual trend of deteriorated microstructure and worsening biomechanical properties along with aberrant bone remodeling, which might be responsible for the inhibition of stress transmission from the articular cartilage to the subchondral bone and thus leading to the cartilage degeneration and accelerated DDH progression.

CONCLUSIONS

Our findings indicate that alternations of subchondral trabecular bone in a time-dependent manner could contribute to the DDH progression and the amelioration on subchondral bone might be a favorable therapeutic candidate for DDH.

The relationship between pre-operative pain characteristics and periacetabular osteotomy outcomes in patients with acetabular dysplasia

The aims of this study were to determine if pre-operative pain characteristics (location of maximum severity of pain, presence of non-groin pain, maximum severity of pain and number of pain locations) affect patient-reported outcome measures in patients undergoing periacetabular osteotomy (PAO) for acetabular dysplasia. We reviewed 52 hips (48 patients) treated with PAO for acetabular dysplasia from February 2017 to July 2020 using modified Harris Hip Score (mHHS), Hip Outcome Score (HOS) and international Hip Outcome Tool (iHOT-12) score, radiographic analysis and pain location/severity questionnaires. Descriptive statistics, analysis of covariance and Spearman partial correlation coefficients were implemented. Twenty-six hips experienced the most severe pre-operative pain in the groin, and 26 hips experienced equal or greater pain in a non-groin location. Outcome scores between these groups were not significantly different (mHHS P = 0.59, HOS P = 0.48, iHOT-12 P = 0.99). Additionally, the presence of pre-operative pain in any non-groin location had no significant relationship with PROM (all P-values ≥0.14). Furthermore, the maximum severity of pre-operative pain and number of pain locations showed no significant relationship with PROM (maximum severity: mHHS P = 0.82, HOS P = 0.99, iHOT-12 P = 0.36; number of pain locations: mHHS P = 0.56, HOS P = 0.10, iHOT-12 P = 0.62). Varying pre-operative pain characteristics do not appear to have any significant impact on outcomes. Therefore, a wide array of patients with acetabular dysplasia might expect similar, favourable outcomes from PAO regardless of pre-operative pain characteristics.

Total Hip Arthroplasty With the Wagner Cone Femoral Stem in Patients With Crowe IV Developmental Dysplasia of the Hip: A Retrospective Study

BACKGROUND

The aim of this study is to assess treatment of Crowe type IV hip dysplasia with the Wagner cone femoral stem combined with transverse subtrochanteric shortening osteotomy and augmenting the osteotomy site using the intercalary segment as a strut autograft.

METHODS

One hundred twenty-seven hips of 91 patients diagnosed with Crowe type IV hip dysplasia and treated with total hip arthroplasty using the Wagner cone stem combined with transverse subtrochanteric shortening osteotomy were retrospectively evaluated by clinical and radiographic outcomes as well as complications.

RESULTS

The mean follow-up was 8.4 years. The Harris Hip Score and the Western Ontario and McMaster University Osteoarthritis Index scores were significantly improved postoperatively (P = .000). Intraoperative femoral cracks were observed in 70 hips (55.1%) and all femurs healed smoothly. Femoral cracks did not have a significant effect on clinical outcomes, except for heterotopic ossifications (P = .032). The probability of 10-year survivorship of the components free of revision for any reasons as end point was 94.5%; when only the femoral components were considered the survivorship was of 96.9%.

CONCLUSION

Transverse subtrochanteric shortening and augmenting the osteotomy site using the intercalary segment of bone resected from the shortened femur with the Wagner cone stem is an effective and reliable technique in the management of total hip arthroplasty in Crowe type IV hip dysplasia. Stable and firm placing of the femoral component which leads to an increased frequency of intraoperative femoral cracks does not have an unfavorable effect on clinical and radiological outcomes.

[A comparative study of three different fixation methods after subtrochanteric shortening osteotomy in total hip arthroplasty for Crowe type Ⅳ developmental dysplasia of the hip]

Objective

To compare the effectiveness of three different fixation methods after subtrochanteric shortening osteotomy (SSO) in total hip arthroplasty (THA) for Crowe type Ⅳ developmental dysplasia of the hip (DDH).

Methods

A clinical data of 63 patients (78 hips) with Crowe type Ⅳ DDH, who underwent THA with SSO between November 2014 and May 2019, was retrospectively analyzed. Among them, 18 patients (20 hips) obtained stability by intramedullary pressure provided by the S-ROM modular prostheses (group A); 22 patients (30 hips) underwent prophylactic binding by stainless steel wire after osteotomy and before stem implantation (group B); 23 patients (28 hips) were fixed with autogenous cortical strut grafts and stainless steel wire or cables (group C). There was no significant difference in gender, age, body mass index, affected limb side, and preoperative Harris score between groups ( P>0.05). The operation time, complications, imaging results, hip functional score of the three groups were recorded and compared.

Results

There was no significant difference in the operation time between groups ( P>0.05). All incisions healed by first intention. All patients were followed up, and the follow-up time was 2.5-4.0 years (mean, 3.1 years) in group A, 1.5-5.5 years (mean, 3.2 years) in group B, and 1.0-5.0 years (mean, 1.6 years) in group C. There was no significant difference in Harris score or Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score between groups at 4 and 12 months after operation ( P>0.05). X-ray films showed that there was no significant difference in osteotomy healing rate at 4, 8, and 12 months after operation and the osteotomy healing time between groups ( P>0.05). There was no complications such as joint dislocation, prosthesis loosening, prosthetic joint infection, or heterotopic ossification during follow-up, except for the distal femoral fracture of 1 hip during operation in group B.

Conclusion

In THA for patients with Crowe type Ⅳ DDH, the stainless steel wire binding alone and autogenous cortical strut grafts combined with stainless steel wire or cable binding can not significantly promote the osteotomy healing compared with femoral prosthesis intramedullary compression fixation. For patients with nonmatched medullary cavity after SSO, it is recommended to apply autogenous cortical strut grafts with wire or cables for additional fixation.

Bone defect map of the true acetabulum in hip dysplasia (Crowe type II and III) based on three-dimensional image reconstruction analysis

The high hip center technique (HHC) is considered to be feasible for acetabular reconstruction in patients with DDH, but there is little in-depth study of its specific impact on Crowe type II and III DDH. The purpose of this study was to simultaneously analyze the effect of HHC on bone coverage of the cup (CC) in the acetabular reconstruction of type II and III DDH patients and to propose a map of acetabular bone defects from the perspective of the cup. Forty-nine hip CT data of 39 patients with DDH (Crowe type II and III) were collected to simulate acetabular reconstruction by cup models of different sizes (diameter 38mm–50 mm, 2 mm increment) with the HHC technique. The frequency distribution was plotted by overlapping the portions of the 44 mm cups that were not covered by the host bone. The mean CC of cups with sizes of 38 mm, 40 mm, 42 mm, 44 mm, 46 mm, 48 mm, and 50 mm at the true acetabula were 77.85%, 76.71%, 75.73%, 74.56%, 73.68%, 72.51%, and 71.75%, respectively, and the maximum CC increments were 21.24%, 21.58%, 20.86%, 20.04%, 18.62%, 17.18%, and 15.42% (P < 0.001), respectively, after the cups were elevated from the true acetabula. The bone defect map shows that 95% of type II and III DDH acetabula had posterosuperior bone defects, and approximately 60% were located outside the force line of the hip joint. Acetabular cups can meet a CC of more than 70% at the true acetabulum, and approximately 60% of Crowe type II and III DDH patients can obtain satisfactory CC at the true acetabulum by using a 44-mm cup without additional operations.

Is intraoperative neuromonitoring effective in hip and pelvis orthopedic and trauma surgery? A systematic review

INTRODUCTION

Sciatic nerve injury is an uncommon but potentially devastating complication in hip and pelvis surgery. Intraoperative nerve monitoring (IONM) was applied since the seventies in neurosurgery and spine surgery. Nowadays, IONM has gained popularity in other surgical specialities including orthopaedic and trauma surgery. Aim of this systematic review is to resume the literature evidences about the effectiveness of intraoperative monitoring of sciatic nerve during pelvic and hip surgery.

METHODS

Two reviewers (GC and MD) independently identified studies by a systematic search of PubMed and Google Scholar from inception of database to 10 January 2021. Inclusion criteria were: (a) English written papers, (b) use of any type of intraoperative nerve monitoring during traumatic or elective pelvic and hip surgery, (c) comparison of the outcomes between patients who underwent nerve monitoring and patient who underwent standard procedures, (d) all study types including case reports. The present review was conducted in accordance with the 2009 PRISMA statement.

RESULTS

The literature search produced 224 papers from PubMed and 594 from Google Scholar, with a total amount of 818 papers. The two reviewer excluded 683 papers by title or duplicates. Of the 135 remaining, 72 were excluded after reading the abstract, and 31 by reading the full text. Thus, 32 papers were finally included in the review.

CONCLUSIONS

The use of IONM during hip and pelvis surgery is debated. The review results are insufficient to support the routine use of IONM in hip and pelvis surgery. The different IONM techniques have peculiar advantages and disadvantages and differences in sensitivity and specificity without clear evidence of superiority for any. Results from different studies and different interventions are often in contrast. However, there is general agreement in recognizing a role for IONM to define the critical maneuvers, positions or pathologies that could lead to sciatic nerve intraoperative damage.

LEVEL OF EVIDENCE

Level 2.

Minimum 10-Year Results of Cementless Ceramic-On-Ceramic Total Hip Arthroplasty Performed With Transverse Subtrochanteric Osteotomy in Crowe Type IV Hips

BACKGROUND

Total hip arthroplasty (THA) performed for developmental dysplasia of the hip is a technically difficult procedure with a high complication rate, especially in the presence of completely dislocated hips. This study aimed to evaluate at least 10 years of follow-up results of cementless, ceramic-on-ceramic (CoC) THA performed with transverse subtrochanteric osteotomy in Crowe type IV hips.

METHODS

We retrospectively reviewed 50 patients' 67 hips that underwent CoC, cementless THA with transverse subtrochanteric osteotomy between 2008 and 2011. Clinical and radiological data of the hips were examined. Clinical results were evaluated using the Harris Hip Score and the Western Ontario and McMaster Universities Osteoarthritis Index.

RESULTS

The mean Harris Hip Score improved from 22.9 ± 9.9 preoperatively to 94.1 ± 8.1 at the final follow-up (P < 0.001). The median Western Ontario and McMaster Universities Osteoarthritis Index score improved from 72 (interquartile range: 17) preoperatively to 2 (interquartile range: 17) postoperatively (P < 0.001). The preoperative mean leg length discrepancy was improved from 4.9 ± 1 cm to 1.5 ± 1 cm in unilateral cases at the last follow-up (P < 0.001). Revision surgery was required because of nonunion in two patients, prosthetic infection in one patient, and aseptic femoral loosening in the other patient. The overall ten-year survival rate was 94% for femoral stems and 98.5% for acetabular components as per Kaplan-Meier survival analysis.

CONCLUSION

Transverse subtrochanteric shortening osteotomy combined with using cementless acetabular and femoral components with a CoC bearing surface promises successful clinical results and high prosthesis survival in the treatment of Crowe IV hips at long-term follow-up.

Robotic-arm assisted THA can achieve precise cup positioning in developmental dysplasia of the hip : a case control study

AIMS

This study aimed to evaluate the accuracy of implant placement with robotic-arm assisted total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH).

METHODS

The study analyzed a consecutive series of 69 patients who underwent robotic-arm assisted THA between September 2018 and December 2019. Of these, 30 patients had DDH and were classified according to the Crowe type. Acetabular component alignment and 3D positions were measured using pre- and postoperative CT data. The absolute differences of cup alignment and 3D position were compared between DDH and non-DDH patients. Moreover, these differences were analyzed in relation to the severity of DDH. The discrepancy of leg length and combined offset compared with contralateral hip were measured.

RESULTS

The mean values of absolute differences (postoperative CT-preoperative plan) were 1.7° (standard deviation (SD) 2.0) (inclination) and 2.5° (SD 2.1°) (anteversion) in DDH patients, and no significant differences were found between non-DDH and DDH patients. The mean absolute differences for 3D cup position were 1.1 mm (SD 1.0) (coronal plane) and 1.2 mm (SD 2.1) (axial plane) in DDH patients, and no significant differences were found between two groups. No significant difference was found either in cup alignment between postoperative CT and navigation record after cup screws or in the severity of DDH. Excellent restoration of leg length and combined offset were achieved in both groups.

CONCLUSION

We demonstrated that robotic-assisted THA may achieve precise cup positioning in DDH patients, and may be useful in those with severe DDH. Cite this article: Bone Joint Res 2021;10(10):629-638.

Changes in Distribution of Lower Limb Alignment After Total Hip Arthroplasty for Crowe IV Developmental Dysplasia of the Hip

Purpose

The purpose of this study was to evaluate the distribution of lower limb alignment in Crowe IV developmental dysplasia of the hip (DDH) before and after total hip arthroplasty (THA).

Patients and Methods

We retrospectively included 64 Crowe IV DDH patients (87 hips) who underwent THA between February 2010 and May 2019. Radiographic parameters were measured on full limb length standing anteroposterior radiographs, including hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA), anatomical lateral distal femoral angle (aLDFA), and anatomical tibiofemoral angle (aTFA).

Results

HKA improved from 176.54°±3.52° preoperatively to 179.45°±4.31° at the last followup (P<0.001). According to the preoperative HKA, 40 hips were defined as knee valgus alignment. The majority of them were characteristic of a valgus mLDFA and a valgus or neutral mMPTA (35%, 47.5%). After THA, there were still 22 hips defined as knee valgus alignment. More than 50% of them were characteristic of a valgus mLDFA and a neutral mMPTA. Five hips (22.7%) revealed valgus alignment in both mLDFA and mMPTA. Twenty-one hips (24.1%) remained knee valgus alignment before and after surgery. One hip, defined as neutral alignment, preoperatively turned into valgus alignment after surgery.

Conclusion

Both preoperative and postoperative sources of valgus alignment were mainly from the femoral side among Crowe IV DDH patients. THA mainly played a positive role in the reconstruction of lower limb alignment in these patients.

Postoperative radiographic evaluation and simulation study for optimal cup placement in high-hip centre total hip arthroplasty

BACKGROUND

Achieving favourable outcomes in high-hip centre reconstruction in hip dysplasia requires the optimal cup height and size, which can provide sufficient bone coverage for stable cup fixation that fits the anteroposterior acetabular rim without increasing the cup height more than necessary.

METHODS

We retrospectively reviewed 214 patients who underwent primary total hip arthroplasty (THA) and identified 30 hips with Crowe II (n = 15) or III (n = 15) developmental dysplasia of the hip (DDH). We measured the cup-centre-edge angle (cup-CE) and the vertical and horizontal distances from the teardrop. In a simulation study, we examined the cup-CE and optimal cup size by changing the cup height in 5-mm increments over a distance of 15-40 mm above the inter-teardrop line using a 3-dimensional template system.

RESULTS

Postoperative radiographic evaluation revealed a mean cup-CE of 19.9° in Crowe II hips and 15.2° in Crowe III hips; the respective mean vertical distances were 26.6 mm and 27.6 mm (p = 0.511). There was no evidence of cup loosening or lateralisation at a minimum of 7 years (7-11 years) follow-up. Simulation showed that the hip centre needed to be elevated to 20 mm to acquire a cup-CE of more than 0°. More than 10° of cup-CE could be expected by elevating the hip centre to 25 mm in both Crowe II and III.

CONCLUSIONS

Even in severe DDH, a high-hip centre positioned approximately 25 mm superior to the inter-teardrop line was sufficient to achieve optimal bone coverage, which could lead to more secure cup fixation.

Total Hip Replacement in Developmental Hip Dysplasia: A Narrative Review

The reconstruction of the hip joint in patients suffering from developmental hip dysplasia (DDH) is a demanding procedure and presents many challenges to the reconstructive surgeon. Higher rates of mechanical complications are present in this group of patients. The results of cemented and uncemented implants used in DDH patients are very promising, according to recent outcomes. However, the surgeon has to be aware of several complications, in order to establish an uneventful surgical management of DDH. The specific article investigates the technical challenges and clinical results of total hip arthroplasty in patients with DDH.

Accuracy of cup position following robot-assisted total hip arthroplasty may be associated with surgical approach and pelvic tilt

This study aimed to investigate the accuracy of cup placement and determine the predictive risk factors for inaccurate cup positioning in robot-assisted total hip arthroplasty (THA). We retrospectively analyzed 115 patients who underwent robot-assisted THA between August 2018 and November 2019. Acetabular cup alignment and three-dimensional (3D) position were measured using pre- or postoperative computed tomography (CT) data. Absolute differences in cup inclination, anteversion, and 3D position were assessed, and their relation to preoperative factors was evaluated. The average measurement of the absolute differences was 1.8° ± 2.0° (inclination) and 1.9° ± 2.3° (anteversion). The average absolute difference in the 3D cup position was 1.1 ± 1.2 mm (coronal plane) and 0.9 ± 1.0 mm (axial plane). Multivariate analysis revealed that a posterior pelvic tilt [odds ratio (OR, 1.1; 95% confidence interval (CI), 1.00–1.23] and anterior surgical approach (OR, 5.1; 95% CI, 1.69–15.38) were predictive factors for inaccurate cup positioning with robot-assisted THA. This is the first study to demonstrate the predictive risk factors (posterior pelvic tilt and anterior surgical approach) for inaccurate cup position in robot-assisted THA.

Bilateral Total Hip Arthroplasty in the Setting of Developmental Dysplasia of the Hip and Extreme Hip Flexion Requirements due to Phocomelia

Phocomelia is a rare congenital birth defect marked by hypoplastic or markedly absent limbs. Developmental dysplasia of the hip (DDH) is a congenital disorder with a failure of the native acetabulum to provide complete coverage over the femoral head. The secondary osteoarthritis that develops from DDH is technically challenging for orthopedic surgeons because of distorted anatomy. The present case describes the diagnosis of Crowe 3 DDH in a phocomelia patient with hyperflexion requirements who successfully underwent staged bilateral total hip arthroplasty via a direct anterior approach. It highlights the utility of preoperative computerized tomography and intraoperative computer navigation to assist in implant placement. Recognizing difficult arthroplasty cases in advance is imperative as these cases may require great expertise and more extensive surgical planning.

Functional and radiographical results of asymmetrically reconstructed total hip arthroplasty in patients with bilateral dysplastic arthritic hips with one hip Crowe II-III and the other Crowe IV: a retrospective cohort study

Background

The study aimed to evaluate the functional and radiographical results of asymmetrically reconstructed total hip arthroplasty in patients with bilateral dysplastic arthritic hips with one hip Crowe II–III and the other hip Crowe IV.

Materials and methods

From April 2006 to April 2019, we evaluated 23 patients who had a reconstruction of one Crowe II–III hip with high hip center (HHC) and the other Crowe IV hip at the anatomical position (H group). The radiographic and clinical outcomes were compared with those of a control group of 19 patients with bilateral dysplasia who had one Crowe IV hip and the contralateral hip both reconstructed in the anatomical position (A group). Medical records and radiographs were reviewed, and a complete follow-up was conducted for all patients.

Results

The mean vertical center of rotation (V-COR) and horizontal center of rotation (H-COR) in the H group were 30.6 ± 5.8 mm and 30.0 ± 5.5 mm, respectively. In the A group, the corresponding values were 14.0 ± 4.3 mm and 23.0 ± 2.3 mm, respectively. A significant difference was found in terms of V-COR and H-COR between the two groups, and no significant difference was shown regarding the cup inclination, abductor lever arm (ALA), ALA ratio, and leg length discrepancy (LLD). Three patients of the H group and four patients of the A group exhibited LLD > 10 mm. All seven patients who had LLD > 10 mm underwent the shortening subtrochanteric osteotomy (SSTO) of the Crowe IV hip. Subgroup analysis based on the presence and absence of SSTO showed that the LLD of the SSTO group was greater than that of the non-SSTO group in both groups, but the difference was only statistically significant in the A group. At the last follow-up, the mean Harris Hip Scores significantly improved in the two groups, and there was no revision during the follow-up period. In the H group, four patients presented with a slight limp and three patients with a moderate limp, while it was six patients and one patient in the A group, respectively.

Conclusions

Asymmetrical reconstruction in patients with bilateral dysplastic arthritic hips with one hip Crowe II–III and the other Crowe IV is acceptable and comparable when compared with bilateral anatomical reconstruction.

Level of evidence

III, retrospective observational study.

Trial registration Chinese Clinical Trail Registry. ChiCTR2000033848

Acetabular Morphology in Patients with Developmental Dysplasia of the Hip with High Dislocation

Purpose

The current study aimed to investigate the morphology of the true acetabulum in developmental dysplasia of the hip (DDH) with high dislocation. A secondary was to evaluate the acetabular cup placement in patients with high dislocation who were treated with total hip arthroplasty (THA).

Materials and Methods

Using a retrospective design, 23 hips with DDH with high dislocation in patients who were treated with THA were included in this study. We measured the depth, width and thickness of the anterior and posterior walls of the original acetabulum using preoperative computed tomography images and investigated the cup size applied in these cases.

Results

The mean depth and width of the acetabulum was 18.4 and 16.2 mm proximal end, 18.4 and 24.3 mm in the middle, and 15.8 and 27.6 mm at the distal part. Mean thickness of the anterior and posterior walls was 10.9 and 23.9 mm at the proximal end, 10.3 and 22.2 mm in the middle, and 10.9 and 22.7 mm at the distal part. A 42-mm cup was using in one hip, a 46-mm cup in three hips, a 48-mm cup in 13 hips, and a 50-mm cup in six hips.

Conclusion

In patients with Crowe IV DDH, the morphology of the acetabulum comprises a triangle that broadens from proximal to distal points, with a relatively thick posterior wall. Reaming the acetabulum posteriorly and inferiorly may enable the placement of a relatively larger cup to achieve stable fixation.

Long-Term Outcomes of Total Hip Arthroplasty With Transverse Subtrochanteric Shortening Osteotomy and Modular Stem in Crowe IV Developmental Dysplasia

BACKGROUND

The reconstruction of high dislocation related to developmental dysplasia of the hip (DDH) remains challenging for joint surgeons. The aim of this study is to evaluate the rate of union, the revision rate, functional scores, and complications in patients with Crowe IV DDH treated with total hip arthroplasty, transverse subtrochanteric shortening osteotomy, and modular stem in an average 10-year follow-up.

METHODS

Twenty-eight patients (33 hips) with Crowe IV DDH who were operated on between 2008 and 2013 were followed. All patients underwent uncemented total hip arthroplasty with transverse subtrochanteric shortening osteotomy and anatomical acetabular cup implantation. The mean age was 36.6 years, and the mean follow-up period was 121 months. Clinical and radiological outcomes were evaluated.

RESULTS

The mean Harris Hip Score significantly improved from 47.0 preoperatively to 89.6 postoperatively. The mean limb length discrepancy was significantly reduced from 3.8 to 0.8 cm. The mean osteotomy union time was 6.8 months. At the mean follow-up of 121 months, there were 3 cases of postoperative dislocation, 2 cases of intraoperative fracture, and 1 case of posterior tibial venous thrombosis. No revision occurred, and no signs of component loosening or migration were observed at the last follow-up.

CONCLUSION

Crowe IV DDH patients treated with transverse subtrochanteric shortening osteotomy, modular stem, and anatomic acetabular component insertion can have satisfactory and reliable 10-year clinical outcomes.

Post-THA gait training to improve pelvic obliquity and decrease leg length discrepancy in DDH patients: a retrospective study

Objectives

To investigate the value of a post-operative gait training program to improve pelvic obliquity (PO) and decrease leg length discrepancy (LLD) for patients with Crowe type I developmental dysplasia of the hip (DDH) undergoing unilateral total hip arthroplasty (THA).

Methods

The prospective group consisted of 35 patients who underwent one-stage unilateral THA. Pre- and post-training PO and LLD were measured for the radiological assessment and Harris Hip Score (HHS) was used for the functional assessment.

Results

The HHS improved from 55.54 ± 10.61 pre-operatively to 84.97 ± 7.63 after surgery. The mean post-training PO angle for grade 0, grade 1, and grade 2 were 2.66 ± 1.42, 2.94 ± 1.42, and 5.60 ± 1.90, respectively, compared with pre-training values of 1.42 ± 0.58, 4.17 ± 0.90, and 6.96 ± 0.46. The mean post-training LLD for grade 0, grade 1, and grade 2 were 0.83 ± 0.91, 0.56 ± 0.48, and 0.36 ± 0.30, respectively, compared with pre-training values of 0.70 ± 0.23, 1.25 ± 0.90, and 1.46 ± 1.60.

Conclusion

Gait training following unilateral THA can improve PO and decrease functional LLD in grade I DDH patients. This method may have moderate success for grade 0 DDH patients and provide limited benefit for grade II patients. Appropriate release of the soft tissues may be required for grade II DDH patients to obtain a better walking gait.

Total hip arthroplasty for Crowe type IV developmental dysplasia of the hip combined with intertrochanteric fracture: a case report and literature review

BACKGROUND

Total hip arthroplasty for Crowe type IV developmental dysplasia of the hip (DDH) is a complex procedure. Crowe type IV DDH combined with intertrochanteric frature is very rare.

CASE PRESENTATION

A 75-year-old patient suffering from left hip pain after a fall was sent to our hospital. Plain radiographs and computed tomography scans were used to diagnose this patient with DDH combined with an intertrochanteric fracture. We conducted a total hip arthroplasty using an S-rom prosthesis following subtrochanteric shortening osteotomy in this patient, after which steel wires were used to fix the intertrochanteric fracture. The patient did not suffer any significant intraoperative or postoperative complications, and treatment was sufficient to overcome lower leg abnormalities. The patient was encouraged to resume walking with support at 3 days post-surgery, and at 6-month postoperatively he had regained the majority of his original range of motion. At 10-month postoperatively, the intertrochanteric fracture and subtrochanteric osteotomy of left femur had healed effectively,and the patient's VAS and mHSS scores had improved significantly.

CONCLUSIONS

Total hip arthroplasty is an effective approach to treat patients suffering from Crowe type IV DDH combined with an intertrochanteric fracture, and can achieve satisfactory clinical outcomes.

Segmental uncoverage ratio analysis of Crowe type-IV developmental dysplasia of the hip via 3-dimensional implantation simulation

BACKGROUND

To study the segmental uncoverage ratio (UCR) of a 44-mm cup model placed in a true acetabulum of Crowe type-IV developmental dysplasia of the hip via 3-Dimensional (3D) implantation simulation.

METHODS

Qualified CT imaging data of 26 patients (involving 30 hips) with Crowe type-IV DDH were imported into Mimics software for reconstruction. Then a 44-mm eggshell cup model was placed in a true acetabulum. First, total uncoverage ratio (TUCR) was measured. Then the virtual cup was divided into 4 segments according to the quadrant setting of the true acetabulum, i.e., anterior-superior (A-S) segment, anterior-inferior (A-I) segment, posterior-superior (P-S) segment and posterior-inferior (P-I) segment. The UCRs of the aforementioned segments were measured, i.e., anterior-superior uncoverage ratio (A-SUCR), anterior-inferior uncoverage ratio (A-IUCR), posterior-superior uncoverage ratio (P-SUCR) and posterior-inferior uncoverage ratio (P-IUCR). The acetabular height and anterior-posterior diameter on the 3-D model were also calculated. Statistic analyses were performed by using SPSS software package.

RESULTS

TUCR was 0.2958 ± 0.1003 (95% [CI], 0.1020 to 0.5400) in this cohort of Crowe Type-IV hips. P-SUCR had the greatest value among all the segmental UCRs (0.1012 ± 0.0435, 95% confidence interval [CI],0.0152 to 0.1914) and the most significant positive correlation with TUCR (Pearson correlation = 0.889, p < 0.01. Linear regression R² = 0.791). Similarly, P-IUCR and A-SUCR showed a significant positive correlation with TUCR. However, A-IUCR exhibited no correlation with either total or other segmental UCRs. P-SUCR was found to bear significant positive correlation with P-IUCR (pearson correlation = 0.644, p < 0.01. Linear regression R² = 0.415). Acetabular height and A-P diameter were not correlated with TUCR.

CONCLUSION

Implantation of a 44-mm cup into Crowe type IV acetabulum is feasible and could achieve acceptable host bone coverage in most of the cases. P-SUCR contributed most to TUCR. TUCR had no linear relationship with the size of the host acetabulum, suggesting that the pre-operative plan should be individualized.

Crowe Type IV Hip Dysplasia Treated by THA Comebined with Osteotomy to Balance Functional Leg Length Discrepancy: A Prospective Observational Study

Objective

To measure the factors that affect functional leg length of Crowe type IV Developmental dysplasia of the hip (DDH) patients and to review our own methods to balance leg length discrepancy (LLD) in Crowe type IV DDH patients.

Methods

This was a prospective observational study which started in June 2017 and ended in August 2019. Inclusion criteria included: (i) Crowe type I or Crowe type IV hip dysplasia patients who underwent total hip arthroplasty (THA) in the Department of Orthopaedics at our institution between July 2017 and June 2018; (ii) the patients were treated with our specific leg length balance strategy; and (iii) the related outcomes of patients were completely recorded. Finally, 18 consecutive Crowe type I patients (20 hips) and 14 consecutive Crowe type IV patients (18 hips) were selected and divided into two groups according to Crowe types. All patients received THA, and patients with a longer affected side and inferior anatomical acetabular positions in Crowe type IV group also received subtrochanteric osteotomy. During operation and after hip reduction, leg lengths were compared while two legs were in an extended position and the operative leg was on top of the non‐operative one. Additional leg length adjustment was applied when leg length was considered to be unequal. Prior to surgery, subluxation height of the femoral head on the affected side, functional LLD, bony length of lower limbs, and distance from teardrops to the lowest point line of the sacroiliac joint were recorded. After surgery, cup sizes, functional LLD, and height of hip rotational centers were measured. Clinical evaluations, such as Harris Hip Score (HHS) and SF‐12 scale, were also obtained before and after surgery for all patients.

Results

At the last follow‐up, functional LLD and clinical measurements of both Crowe type IV group and Crowe type I group were significantly improved. Compared with Crowe type I patients, Crowe type IV patients had a significantly lower MCS, a significantly longer leg lengthening length and a significantly lower hip center height after surgery. Significant differences of tibia length, leg length, and teardrop position were found between affected side and healthy side of Crowe type IV patients. Only three of 14 Crowe type IV patients remained under 1 cm functional LLD. Five patients in the Crowe type IV group developed lower limb numbness immediately following surgery, and they all recovered within 6 months. The average follow‐up period for either group was 14 months, and all patients were followed‐up at 1, 3, 6, and 12 months then yearly after surgery until the final follow‐up.

Conclusion

After detailed leg length balance process, THA combined with transverse sub‐trochanter osteotomy could be an effective method to achieve equal function leg length with most Crowe type IV patients.

Changes in expression of serum chemokine CXCL13 and IL-6 after hip replacement, and the relationship with lower limb vein thrombus

Changes in the expression of serum chemokine CXC ligand 13 (CXCL13) and interleukin-6 (IL-6), and the relationship with lower limb vein thrombus were explored. A total of 128 patients undergoing hip replacement in The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine from May 2017 to June 2019 were selected, and the patients suffering from lower limb vein thrombus were enrolled as group A and other patients not suffering from it were enrolled as group B. Enzyme-linked immuno-sorbent assay was employed to determine the levels of serum chemokine CXCL13 and IL-6, and receiver operating characteristic curves of serum chemokine CXCL13 and IL-6 levels in diagnosing restenosis after surgery were drawn. Pearson's correlation coefficient was adopted to analyze the correlation between serum chemokine CXCL13 and IL-6, and the logistic regression analysis to analyze the risk factors affecting hip replacement in patients. The levels of serum CXCL13 and IL-6 in group A were significantly higher than those in group B (both P<0.001). The specificity and sensitivity of serum CXCL13 level in diagnosis of lower limb vein thrombus after hip replacement were 61.76 and 80.00%, respectively, and those of serum IL-6 level in diagnosis were 70.59 and 66.67%, respectively. Serum CXCL13 level was positively correlated with serum IL-6 level (P<0.001), and age, body mass index (BMI), CXCL13 level and IL-6 level of the patients were independent risk factors affecting the efficacy of hip replacement. Serum CXCL13 level and serum IL-6 level can be used as biological indexes for prediction of early lower limb vein thrombus after hip replacement, and logistic regression analysis revealed that the age of the patients, BMI, diabetes history, hyperlipidemia history, hypertension history, CXCL13 level and IL-6 level are independent risk factors affecting the efficacy of hip replacement.

[Research progress of total hip arthroplasty for patients with sequelae of suppurative hip arthritis]

OBJECTIVE

To summarize the research progress of total hip arthroplasty (THA) in treatment of sequelae of suppurative hip arthritis.

METHODS

The relevant literature was systematically searched and the operation timing, treatments of acetabular and femoral sides, and prosthesis selection in THA for sequelae of suppurative hip arthritis were summarized.

RESULTS

THA is an effective way to treat the sequelae of suppurative hip arthritis. In order to avoid the recurrence of infection, THA is recommended to be performed after 10 years of resting period of hip septic infection. These patients may have acetabulum dysplasia and poor coverage of acetabulum. When performing THA, high position acetabulum, osteotomy of the medial acetabular wall, structural bone graft, Cage, tantalum augment, or three-dimensional printing prosthesis can be chosen. The femoral side may has small medullary cavity, increased femoral neck anteversion, increased femoral neck-stem angle, extend trochanter, and poor bone mass. When performing THA, the femoral osteotomy and appropriate prosthesis can be selected for treatment. The patients with sequelae of suppurative hip arthritis are mostly young, cementless THA is preferred for a better long-term survivorship.

CONCLUSION

THA is an effective method for the sequelae of suppurative hip arthritis, but the operation is difficult and has relative high complication rate. Surgeons should have full understanding.

Best bone of acetabulum for cup component placement in Crowe types I to III dysplastic hips: a computer simulation study

BACKGROUND

During cup implantation, vertical height of the cup center (V-HCC) should be precisely controlled to achieve sufficient bone-cup coverage (BCC). Our study aimed to investigate the acetabular bone stock and the quantitative relationship between V-HCC and BCC in Crowe types I to III hips.

METHODS

From November 2013 to March 2016, pelvic models of 51 patients (61 hips) with hip dysplasia were retrospectively reconstructed using a computer software. Acetabular height and doom thickness were measured on the mid-acetabular coronal cross section. V-HCC was defined as the vertical distance of cup rotational center to the interteardrop line (ITL). In the cup implantation simulation, the cup was placed at the initial preset position, with a V-HCC of 15 mm, and moved proximally by 3-mm increments. At each level, the BCC was automatically calculated by computer. Analysis of variance and Kruskal-Wallis test were used to compare the differences between groups.

RESULTS

There were no significant between-group differences in maximum thickness of the acetabular doom; however, peak bone stock values were obtained at heights of 41.63 ± 5.14 mm (Crowe type I), 47.58 ± 4.10 mm (Crowe type II), and 55.78 ± 3.64 mm (Crowe type III) above the ITL. At 15 mm of V-HCC, median BCC was 78% (75-83%) (Crowe type I), 74% (66-71%) (Crowe type II), and 61% (57-68%) (Crowe type III). To achieve 80% of the BCC, the median V-HCC was 16.27 (15.00-16.93) mm, 18.19 (15.01-21.53) mm, and 24.13 (21.02-28.70) mm for Crowe types I, II, and III hips, respectively.

CONCLUSION

During acetabular reconstruction, slightly superior placement with V-HCC <25 mm retained sufficient bone coverage in Crowe I to III hips.

Total hip arthroplasty in an adult patient with pelvic dysmorphism, unilateral sacroiliac joint autofusion, and developmental hip dysplasia

This case describes the challenges associated with total hip arthroplasty in a patient with unique anatomy, including developmental dysplasia of the hip, pelvic dysmorphism, and unilateral sacroiliac joint autofusion. A 30-year-old female, with a history of developmental dysplasia of the hip treated with presumed pelvic osteotomy complicated by postoperative infection, presented with hip pain refractory to conservative management. Radiographic studies demonstrated a 10-cm leg length discrepancy, 20° of acetabular retroversion, severe hemipelvic dysmorphism, ipsilateral sacroiliac joint autofusion, and significant femoral head dysplasia. Total hip arthroplasty was performed using a revision acetabular component and modular femoral component, resulting in improvement in the postoperative leg length discrepancy. There were no neurovascular or other perioperative complications, and the patient was ambulating without pain or assistive devices at 1-year follow-up.