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

Surgical Outcomes of Total Hip Arthroplasty With Paavilainen Osteotomy in Patients Who Have High Developmental Hip Dislocation: Mean 4.4-Year Follow-Up

BACKGROUND

Although subtrochanteric osteotomy is a common procedure, the use of Paavilainen osteotomy combined with total hip arthroplasty (THA) for high developmental hip dislocation is less documented. This study assessed the efficacy and complications of this approach, with a particular focus on the risk factors for nonunion postosteotomy.

METHODS

All patients who had high dislocated hip dysplasia who underwent combined THA and Paavilainen osteotomy were retrospectively reviewed with over 1 year of follow-up. A total of 44 patients (51 hips) were included, with an average follow-up period of 4.4 years (range, 1.97 to 6.94). Anatomical data of the hip joints were measured on preoperative and postoperative radiographs. Demographic data, Trendelenburg sign, complications related to this procedure, Harris Hip Score, and EuroQoL-5-Dimension 5-Level health questionnaire were collected from the medical chart. Binary logistic regression analysis was used to identify predictors for bone nonunion.

RESULTS

Out of the 51 hips, eight displayed a positive Trendelenburg sign. Patients' Harris Hip Score saw an improvement from 43.8 ± 11.8 preoperatively to 85.7 ± 11.1 at the latest follow-up (P < 0.001), accompanied by a substantial enhancement in the average EuroQoL-5-Dimension 5-Level score from 0.38 ± 0.15 to 0.87 ± 0.13 (P < 0.001). Non-union, as the most concerning complication, occurred in 12% (seven of 56) of osteotomy cases. The contact length between the osteotomy block and femoral cortex was a key risk factor for nonunion. The receiver operating characteristic analysis identified 2.15 cm as the critical bone contact length for healing.

CONCLUSIONS

Paavilainen osteotomy combined with THA and subtrochanteric osteotomy proved effective and less complex than other techniques for high-dislocation hip dysplasia. A bone contact length between the greater trochanteric fragment and the femoral cortex of less than 2.15 cm is a risk factor for nonunion.

Primary total hip arthroplasty using custom-made acetabular implants in patients with high hip dislocation : surgical technique and results

Aims

Despite good results of using uncemented press-fit cups in patients with high hip dislocations (type C as per the Hartofilakidis classification), there are reports of loosening of these components. To improve the results on the acetabular side in patients with high hip dislocations, we used custom-made acetabular implants (CMAIs). The aim of this study was to evaluate the outcomes after total hip arthroplasty (THA) using CMAIs in patients with high hip dislocation.

Methods

We retrospectively analyzed the results of primary THA using the CMAIs in 58 hips (52 patients) from November 2017 to December 2019. All surgeries were performed using the femoral shortening osteotomy technique described by Paavilainen. Type C1 and C2 dislocations were observed in nine and 49 hips, respectively. The presence of various complications, functional results using the Oxford Hip Score (OHS), patient satisfaction, radiological parameters, and positioning of CMAIs were assessed.

Results

The mean follow-up period, including radiological follow-up for all 58 hips, was 5.2 years (4.2 to 6.3; SD 0.71). Patients demonstrated statistically significant improved functional outcomes according to the OHS (preoperatively 16.9 and postoperatively 38.5; p < 0.001). Four hips were revised: two hips due to dislocations, the cause of which was impingement of the greater trochanter due to malposition of the distally advanced greater trochanter after osteotomy. One hip was due to nonunion of the distally advanced greater trochanter after osteotomy, and one hip due to pain resulting from iliopsoas impingement caused by contact of the CMAI flange with the iliopsoas muscle. There were no radiological signs of loosening of the CMAIs. Any deviation of the CMAIs from the planned position was noted.

Conclusion

This preliminary study demonstrated that CMAIs may offer good bone fixation in patients with high hip dislocation; however, further biomechanical studies are needed to evaluate the use of CMAIs in terms of osseointegration, additional screw fixation, and to determine the effect of deviation of CMAIs from the planned position on clinically relevant complications.

Total hip arthroplasty with subtrochanteric osteotomy for severe developmental dysplasia of the hip: A systematic review and meta-analysis

Background

Total hip arthroplasty (THA) for severe developmental dysplasia of the hip (DDH) is technically difficult because of the anatomical features of dysplasia, such as a hypoplastic and shallow acetabulum, narrow femoral canal, and soft tissue contractures. Subtrochanteric osteotomy (STO) is effective technique to reduce the risk of sciatic nerve palsy while placing the acetabular cup in an anatomical position during THA for severe DDH. Few studies have compared THA performed without STO to THA performed with STO. We performed a systematic literature review and single-arm meta-analysis to integrate the results of studies regarding THA with STO for severe DDH.

Patients and methods

A systematic literature review was conducted using relevant original studies from various databases. Pooling of data was performed using RevMan software. A p-value of <0.05 was considered significant. The results are expressed as incidences with 95 % confidence intervals (CIs) for dichotomous data and means with 95 % CI for continuous data. Statistical heterogeneity was assessed based on I 2 using the standard χ2 test. When I 2 > 50 %, significant heterogeneity was assumed, and a random-effects model was applied for the meta-analysis. A fixed-effects model was applied in the absence of significant heterogeneity.

Results

Twelve studies were included in this meta-analysis. The pooled incidence of sciatic nerve palsy, delayed union or nonunion, dislocation, intraoperative femoral fracture, and infection were 2.44 % (95 % CI: 0.86-4.01), 2.74 % (95 % CI: 1.11-4.37), 2.92 % (95 % CI: 1.63-4.20), 2.19 % (95 % CI: 0.95-3.42), and 3.11 % (95 % CI: 0.10-6.12), respectively. Pooling of the data also showed a mean Harris Hip Score (HHS) of 88.33 (95 % CI: 84.95-91.70).

Discussion

Although THA with STO for severe DDH is a challenging surgical procedure, this meta-analysis showed that the results of THA with STO for severe DDH are favourable. Level of evidence: Ⅳ (systematic review and meta-analysis).

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.

Measure Subtrochanteric Osteotomy in Unilateral Crowe-IV Dysplasia-Surgical Technique

OBJECTIVE

Determining the optimal osteotomy length for patients with unilateral Crowe-IV developmental dysplasia of the hip undergoing subtrochanteric osteotomy remains challenging due to the significant variability in pelvic and spinal alignment. Incorrect osteotomy length, compounded by pelvic or spinal tilt, can adversely affect postoperative gait and long-term outcomes. Therefore, this study could introduce a method to calculate the osteotomy length for patients with unilateral Crowe-IV developmental dysplasia of the hip, correcting spinal and pelvic tilt, and improving patient gait.

METHODS

This is a retrospective study that included 28 patients with unilateral Crowe-IV developmental dysplasia of the hip collected from June 2019 to June 2020, who underwent total hip arthroplasty with measured subtrochanteric osteotomy technique. The average follow-up period was 4.3 years (last follow-up). Harris scores, pelvic tilt angles represented by iliac obliquity angle (IO) and sacral obliquity angle (SO), and postoperative complications were recorded. Statistical analysis was performed using independent sample t-tests for normally distributed data and the Mann-Whitney U test for non-normally distributed data.

RESULTS

Postoperatively, pelvic tilt angles improved significantly. The comparison of preoperative and postoperative 3-month IO angles (8.77° ± 3.31° vs. 5.28° ± 2.29°, p = 0.00), and postoperative 3-month and last follow-up (5.28° ± 2.29° vs. 2.88° ± 1.39°, p = 0.00) showed statistically significant differences. Similarly, the comparison of preoperative and postoperative 3-month SO angles (9.56° ± 3.1° vs. 5.81° ± 2.78°, p = 0.00), and postoperative 3-month and last follow-up (5.81 °± 2.78° vs. 3.59° ± 1.72°, p = 0.00) showed statistically significant differences. Harris scores significantly improved from preoperative to 1-year postoperative (47.35 ± 12.32 vs. 80.5 ± 7.81, p = 0.00), and from 1-year postoperative to last follow-up (80.5 ± 7.81 vs. 90.78 ± 2.86, p = 0.00) with statistical significance. There were no significant differences in adverse event rates between the two groups.

CONCLUSION

Total hip arthroplasty combined with measurement subtrochanteric osteotomy technique improves pelvic tilt and Harris scores in Crowe-IV developmental dysplasia patients. This technique may serve as a guideline for determining resection length.

Similar Outcomes between Monoblock and Modular Femoral Stems in Total Hip Arthroplasty with Shortening Osteotomy for Dysplastic Hips at Five Years: A Systematic Review with Meta-analysis

We aimed to examine the outcomes of arthritic congenital dislocation of hip in adults after subtrochanteric shortening derotation osteotomy (SSDO) with cementless hip arthroplasty at a minimum follow-up period of five years. Bibliographic databases were searched and isolated studies were divided into three groups (1, 2, and 3) based on the femoral stem type (modular, monoblock, or mixed). We pooled 931 hips/737 patients from 20 studies. The mean difference in the Harris hip score (HHS) before and after the operation was 47.55 (95% confidence interval [CI] 43.16, 51.94). On subgroup analysis the mean differences of 46.59 (95% CI 41.67, 51.51), 48.24 (95% CI 41.37, 55.11), and 47.30 (95% CI 43.85, 50.75), respectively in HHS were noted in groups 1, 2, and 3. The incidence of uncontrolled proximal femur fractures was comparable at 7.9% and 4.2% in groups 1 and 2; however, it was 0% and 16.6% for controlled fractures. The incidences of nonunion, dislocation, nerve paralysis, heterotopic ossification and revision due to any cause were 0.3%, 6.5%, 1.7%, 2.1%, and 7.9% for group 1 and 1.9%, 4.3%, 1.6%, 5.6%, and 7.4% for group 2. Similar improvements in functional outcome for both monoblock and modular stems can be expected. An increased incidence of controlled proximal femur fractures was observed with use of modular stems. The nonunion at the SSDO site was sporadic.

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.

Adjustment of stem anteversion using tapered cone stem in total hip arthroplasty

Aims

The aim of this study was to evaluate the suitability of the tapered cone stem in total hip arthroplasty (THA) in patients with excessive femoral anteversion and after femoral osteotomy.

Methods

We included patients who underwent THA using Wagner Cone due to proximal femur anatomical abnormalities between August 2014 and January 2019 at a single institution. We investigated implant survival time using the endpoint of dislocation and revision, and compared the prevalence of prosthetic impingements between the Wagner Cone, a tapered cone stem, and the Taperloc, a tapered wedge stem, through simulation. We also collected Oxford Hip Score (OHS), visual analogue scale (VAS) satisfaction, and VAS pain by postal survey in August 2023 and explored variables associated with those scores.

Results

Of the 58 patients (62 hips), two (two hips) presented with dislocation or reoperation, and Kaplan-Meier analysis indicated a five-year survival rate of 96.7% (95% CI 92.4 to 100). Mean stem anteversion was 35.2° (SD 18.2°) for the Taperloc stem and 29.8° (SD 7.9°) for the Wagner Cone stem; mean reduction from Taperloc to Wagner Cone was 5.4° (SD 18.8°). Overall, 55 hips (52 patients) were simulated, and the prevalence of prosthetic impingement was lower for the Wagner Cone (5.5%, 3/55) compared with the Taperloc (20.0%, 11/55) stem, with an odds ratio of 0.20 (p = 0.038). Among the 33 respondents to the postal survey (36 hips), the mean scores were VAS pain 10.9, VAS satisfaction 86.9, and OHS 44.7. A multivariable analysis revealed that reduction of stem anteversion from Taperloc to Wagner Cone was more favourable for VAS pain (p = 0.029) and VAS satisfaction (p = 0.002).

Conclusion

The mid-term survival rate for THA using the Wagner Cone stem was high, which may be supported by a reduction in prosthetic impingement. The reduction in excessive stem anteversion by using a tapered cone stem was associated with reduced pain and increased patient satisfaction.

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.

Cementless Total Hip Arthroplasty With Paavilainen Femoral Shortening Osteotomy Can Provide Good Results at 10 Years in Patients Who Have Crowe IV Developmental Dysplasia of the Hip

BACKGROUND

The aim of this study was to present the clinical and radiologic results of primary total hip arthroplasty (THA) using the femoral shortening osteotomy technique described by Paavilainen in patients who have Crowe IV developmental dysplasia of the hip.

METHODS

We retrospectively analyzed the results of primary THA using the Paavilainen technique in 335 hips. The mean follow-up was 10.2 years. The degree of limp, leg-length discrepancy, and patient satisfaction were assessed. The Oxford Hip Score was used to examine functional outcomes. A number of radiographic parameters were also assessed.

RESULTS

The most common reason for revision surgery was nonunion of the distally advanced greater trochanter. This complication was observed in 22 hips (6.5%). The 10-year survival for acetabular components, it was 97.3%, and for femoral components was 98.7% with aseptic loosening as the end point, and 85.9% with reoperation for any reason as the end point. Patients demonstrated improved functional outcomes. The mean limb lengthening was 27.8 mm. Nonunion was more common if the contact length of the proximal femoral fragment with the lateral surface of the distal femoral fragment was less than 35 mm.

CONCLUSIONS

Cementless primary THA using the femoral shortening osteotomy technique described by Paavilainen in patients who have Crowe IV dysplasia of the hip demonstrates good clinical and radiologic postoperative results. If the contact between the fragments after osteotomy is less than 35 mm, there is a high risk of nonunion, and supplemental fixation may be warranted.

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.

Total hip arthroplasty with porous tantalum trabecular metal pads in patients with Crowe IV developmental dysplasia of the hip: a midterm followup study

PURPOSE

Crowe IV developmental dysplasia of the hip (DDH) is a catastrophic hip disease. Moreover, obtaining ideal clinical efficacy in conventional total hip arthroplasty (THA) is often difficult. In this study, we aimed to assess the mid-term clinical results of THA with porous tantalum trabecular metal (TM) pads for acetabular reconstruction in the treatment of Crowe IV DDH.

METHODS

A cohort of 28 patients (32 hips) diagnosed with Crowe type IV DDH who underwent acetabular reconstruction during THA using TM pads with scheduled follow-up between 2011 and 2018, were included in this study. Eight cases were men and 24 were women, with a mean age of 48.4 years (range, 36-72 years) and a mean follow-up was 74.3 months (range, 42-132 months). All patients underwent acetabular reconstruction using TM pads and total hip replacement with subtrochanteric osteotomy.

RESULTS

At the final follow-up, 28 hips (87.5%) demonstrated mild or no postoperative limping. The Harris Hip Score improved from 58.4 ± 10.6 preoperatively to 85.6 ± 8.9. The mean pain, stiffness, and function scores on the Western Ontario and McMaster University Osteoarthritis index were 86.5 ± 10.2, 87.3 ± 12.4 and 85.4 ± 11.6 respectively. The mean score of patient satisfaction was 90.4 ± 7.6. Additionally, the SF-12 physical summary score was 41.8 ± 5.6 and the SF-12 mental summary score was 51.6 ± 5.4. TM construct survivorship due to all-cause failure was 90.6% at 5 years with 3 hips at risk, 87.5% at 10 years with 4 hips at risk. The survivorship due to failure from aseptic loosening was 96.9% at 5 years with 1hips at risk and 93.75% at 10 years with 2 hips at risk.

CONCLUSION

This study demonstrated satisfactory mid-term clinical and radiological results with the application of TM pads for acetabular reconstruction combined with THA in patients with Crowe IV DDH.

TRIAL REGISTRATION NUMBER

ChiCTR1800014526, Date: 18/01/2018.

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.

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.

Greater trochanteric osteotomy and subtrochanteric osteotomy in primary/revision total hip arthroplasty

Osteotomy of the femur is necessary in some cases of primary/revision total hip arthroplasty (THA) procedure. There are two mainly used femur osteotomy methods in THA: greater trochanteric osteotomy and subtrochanteric osteotomy. Greater trochanteric osteotomy can improve hip exposure, provide greater stability against dislocation and favorably influence the abductor moment arm. Whether in the primary or revision THA, greater trochanteric osteotomy has its unique position. Subtrochanteric osteotomy adjusts the degree of femoral de-rotation and corrects the leg length. It is widely used in hip preservation and arthroplasty surgery. All osteotomy methods have specific indications, while nonunion is the commonest complication. In this paper, we analyze the greater trochanteric osteotomy and the subtrochanteric osteotomy in primary/revision THA and summarize the characteristics of different osteotomy methods.

Mid-term outcomes of the Wagner Cone Prosthesis™ stem for developmental dysplasia of the hip: minimum two year follow-up

PURPOSE

Treatment of symptomatic developmental dysplasia of the hip (DDH) requires a technically demanding total hip arthroplasty (THA) reconstruction. In patients with DDH, prostheses can be difficult to implant and often face the risk of fracture, mismatch, and loosening. The Wagner Cone Prosthesis™ is a tapered, conical stem which can improve treatment success in this population. We look at midterm survivorship and outcomes of THA for DDH using the Wagner Cone Prosthesis™.

METHODS

We retrospectively analyzed 28 patients (33 hips) with DDH undergoing THA using the Wagner Cone Prosthesis™ between January 2008 and January 2020. Ten, nine, and fourteen included patients were classified as Hartofilakidis A, B, and C, respectively. Survivorship according to Kaplan-Meier analysis was the primary outcome, with re-operation and revision as endpoints. The Oxford hip score (OHS) was used to assess clinical outcome. We used multivariate analysis to determine predictors of poor outcomes. The average follow-up was 4.6 years, with a minimum of two years.

RESULTS

Kaplan-Meier survivorship over the 13-year study period was 93.9 ± 4.2% for all-cause revision as an endpoint and 96.9 ± 3.1% for stem revisions only. The overall reoperation rate was 6.1%, with periprosthetic fracture and dislocation being reasons for re-operation. No patients were revised for aseptic loosening, and no patients were revised for subsidence. OHS improved from 19.3 ± 9.6 (4-39) pre-operatively to 37.6 ± 8.4 (19-48) at latest follow-up (p < 0.05).

CONCLUSION

In patients with DDH, THA with the Wagner Cone Prosthesis™ demonstrates excellent clinical, radiographic, and patient-reported functional outcomes at midterm follow-up.