Metal Artifact Reduction Sequence Magnetic Resonance Imaging Abnormalities in Asymptomatic Patients With a Ceramic-on-Ceramic Total Hip Replacement

BackgroundMetal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) has recently gained increased utilization as a screening modality in patients with a total hip arthroplasty (THA). Fluid collections have been documented in asymptomatic patients with various bearing surfaces. The purpose of this study is to determine the frequency and types of MARS MRI-documented abnormalities in asymptomatic patients with a ceramic-on-ceramic (CoC) THA.MethodsThirty-seven patients (42 hips) with a minimum 2-year follow-up after THA with CoC THA implants were enrolled in this study. The inclusion criteria were the absence of hip pain and the availability of appropriate follow-up radiographs. All patients underwent a MARS MRI. Abnormalities were documented using a previously described method.ResultsFluid collections were observed in 8 (19%) asymptomatic hips in this cohort. Four of the 8 hips demonstrated intracapsular synovitis, and 3 of these hips had a thickened synovium. Extra-articular fluid collections with direct intra-articular communication were identified in 4 hips, with 2 of these hips demonstrating synovial thickening. No signs of osteolysis were noted on radiographs or the MARS MRI scans.ConclusionAsymptomatic fluid collections occur in patients after CoC THA similar to other bearing surfaces. We continue to follow these patients in an effort to determine the clinical significance and natural history of these findings.Level of EvidenceDiagnostic Level IV.     

Eighteen-Year Follow-Up Study of 2 Alternative Bearing Surfaces Used in Total Hip Arthroplasty in the Same Young Patients

BackgroundThis study compares the long-term functional, radiographic, and computed tomography scan outcomes and implant survivorship of ceramic-on-ceramic total hip arthroplasty (C-O-C THA) and ceramic-on-highly cross-linked polyethylene total hip arthroplasty (C-O-HXLPE THA) in the same patients.MethodsIn this randomized, prospective trial conducted between January 1999 and April 2003, 133 patients (266 hips) younger than 55 years were enrolled. Each patient received C-O-C THA in 1 hip and a C-O-HXLPE THA in the other. The mean follow-up was 17.1 years (range, 15-18 years); there were 84 men and 49 women with a mean age of 53 ± 7 years (range, 25-55 years).ResultsAt the latest follow-up, mean Harris hip scores (94 vs 93 points; P = .861), pain scores (43 vs 42 points; P = .651), and patient satisfaction scores (7.8 vs 7.6 points; P = .379) were not different between the 2 groups. Eight hips (3%) in the C-O-C THA had an audible squeaking sound. The mean annual penetration rate of HXLPE was 0.0162 ± 0.032 mm per year. No osteolysis was recorded on radiographs or computed tomography scans in either group. At 17.1 years, the survival rate of the acetabular component was 97% in the C-O-C bearing group and 98% in the C-O-HXLPE bearing group (P = .923). The survival rate of the femoral component was 99% in both groups.ConclusionBoth C-O-C THA and C-O-HXLPE THA functioned well, with no osteolysis at mean of 17.1-year follow-up.     

The Utility of Routine Postoperative Radiographs in the Asymptomatic Total Hip Arthroplasty Patient

BackgroundTotal hip arthroplasty (THA) patients often receive routine radiographs in the year following their index surgery. This study sought to investigate the clinical and economic value of obtaining routine postoperative hip radiographs for asymptomatic patients following primary elective THA.MethodsA retrospective cohort study of consecutive patients who underwent primary elective THA from 2016 to 2019 was conducted. Patients undergoing nonelective or revision THA, radiographic follow-up <10 months, and patients aged <18 years were excluded. All radiographs were reviewed for abnormalities in the first postoperative year by an arthroplasty fellowship-trained orthopaedic surgeon, blinded to the symptoms of the patient.ResultsOf the 327 patients (351 hips) included, 57.2% were women and 68.2% were White, with an average age of 65 years (range, 22-97 years) and average body mass index of 29.1 kg/m² (range, 16.2-49.8 kg/m²). Only four (0.4%) radiographic series revealed abnormalities with the potential to alter postoperative management. One patient experienced a change in management directly related to their abnormal finding (closed reduction for dislocation at 10.2 months postoperatively). The remaining three abnormal radiographic findings included femoral stem subsidence, progressive radiolucencies around an acetabular component, and cement mantle fracture. The average cost for each radiographic series was $155.27, resulting in total direct charges of $167,691.60.ConclusionRoutine postoperative radiographs may be of limited utility in the asymptomatic patient in the first year following elective primary THA. Consideration should be given to limit postoperative radiographs following standard elective THA, while reserving postoperative radiographic evaluation for patients who are symptomatic.Level of EvidenceLevel III.     

Outcomes of Total Hip Arthroplasty for Healed Intertrochanteric Hip Fractures. A Matched Retrospective Cohort Study

BackgroundMany studies have analyzed the outcomes of total hip arthroplasty (THA) after failed intertrochanteric fracture fixation, but not after healed fracture. The objective is to investigate the influence of a prior healed intertrochanteric fracture fixation on the outcomes of a subsequent THA for osteoarthritis.MethodsThis is a matched retrospective cohort study of THA between 43 patients who suffered a prior intertrochanteric fracture successfully managed with internal fixation and 43 patients without prior hip fracture. Mean age was 73.6 vs 74.2 years. A conventional cementless THA was used in both groups. Functional outcome was assessed by the Harris hip score (HHS) and reduced Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. Radiological assessment was also performed.ResultsMean follow-up was 6.6 (range, 5-8) years. The mean operative time and blood transfusion rate were significantly higher in the fracture group (P = .001), but there was no significant difference in the length of stay. HHS significantly improved in both groups. At final follow-up, HHS was significantly higher in nonfracture group (P = .008), but the rate of patients with excellent and good outcomes was similar (P = .616). Western Ontario and McMaster Universities Osteoarthritis Index score at the final follow-up was not different between groups (P = .058). Complication rate was similar between groups. There were no revisions, dislocations, or loose implants in the study group.ConclusionCementless THA provided successful functional outcomes and implant durability at medium term in patients treated for osteoarthritis following healed intertrochanteric fracture fixation, comparable to those without prior fracture who underwent primary THA. Surgical complexity and complication rate were low.     

Total Hip Arthroplasty in Patients With Osteogenesis Imperfecta

BackgroundOsteogenesis imperfecta (OI) comprises a spectrum of disorders that result in bone fragility. This presents unique challenges when performing total joint arthroplasty in patients with OI. The purpose of this study is to determine the survivorship and clinical outcomes of total hip arthroplasty (THA) in patients with OI.MethodsWe retrospectively reviewed our institution’s total joint registry from 1969 to 2018 for all primary THAs in patients with a history of OI. There were 11 patients (13 hips) with a mean follow-up of 13 years (range 6-20). Survivorship free of component revision was determined using Kaplan-Meier analysis. Patient-reported clinical outcomes were assessed using Harris Hip Scores.ResultsAt final follow-up, the status of the implant was known in all 13 hips. One patient (1 hip) was deceased. Four hips (31%) underwent revision surgery at a mean of 9 years (range 5-17). Survivorship free of component revision was 52% at 20 years. Mean Harris Hip Scores at final follow-up were fair (75, 47-97), but significantly improved compared to available preoperative scores (P = .0015). No intraoperative complications occurred during the 13 primary THAs.ConclusionTHA in patients with OI is associated with high revision rates and low survivorship at long-term follow-up. Although this is a very challenging patient population, THA provided these patients with improved functional outcomes. To the authors’ knowledge, this is the largest series of primary THA in patients with OI reported in the literature and therefore provides surgeons with important data regarding the expected outcomes following THA in this unique patient population.Level of EvidenceLevel IV.     

Conversion of Fused Hip to Total Hip Arthroplasty: Long-Term Clinical and Radiological Outcomes

BackgroundDespite promising results at the mid-term followup, several aspects of conversion of the fused hip to total hip arthroplasty (THA) remain controversial. The aim of this study was to evaluate clinical and radiological outcomes with a minimum 5-year followup in patients who underwent conversion of the fused hip to THA.MethodsFifty-seven patients (59 hips) were evaluated. The Harris Hip Score (HHS), range of motion (ROM), and the Visual Analogue Scale (VAS) were used to assess hip function and low back pain. Subjective satisfaction with surgery and the presence of the Trendelenburg sign was also evaluated. Radiological assessment was performed pre- and postoperatively to evaluate loosening and heterotopic ossification (HO).ResultsAfter a mean followup of 13.0 ± 6.2 years, HHS and VAS significantly improved from 46.0 ± 16.7 to 80.8 ± 18.8 and from 4.4 ± 1.5 to 2.1 ± 1.4 (both P < .001), respectively. Twenty-three patients (40.4%) had a positive Trendelenburg sign, and HOs were found in 29 cases (49.1%). An overall 29.8% complication rate was noted. Smoking habits and rheumatoid arthritis were predictive of Trendelenburg sign (P = .046 and P = .038, respectively). Implant survival rate as the end point was 98.7 ± 1.3% at 5 years, 92.4 ± 3.3% at 10 years, 82.1 ± 5.7% at 15 years, and 73.4 ± 8.0% at 20 and 25 years. A worse cumulative implant survival rate was noted in patients who underwent previous hip surgery, defined as any hip operation before fusion (P = .005).ConclusionConversion of the fused hip to hip arthroplasty provides high levels of hip functionality and satisfaction with surgery at long-term followup. An implant survival rate higher than 70% can be expected 25 years postoperatively.     

Midterm Outcomes of Revision Total Hip Arthroplasty With the Use of a Multihole Highly-Porous Titanium Shell

Background

We are reporting on the minimum 5-year outcomes of patients who underwent revision total hip arthroplasty (THA) using a specific highly-porous titanium shell. We assessed (1) aseptic and all-cause survivorship; (2) functional outcomes; (3) complications; and (4) radiographic outcomes.

Contemporary Porous Titanium Acetabular Components for Total Hip Arthroplasty After Pelvic Radiation

BackgroundPatients undergoing primary total hip arthroplasty (THA) following pelvic radiation have historically had poor survivorship free of aseptic acetabular component loosening. However, several series have reported improved results with tantalum acetabular components. The purpose of this study is to assess implant survivorship, radiographic results, and clinical outcomes of contemporary, porous titanium acetabular components in the setting of prior pelvic radiation.MethodsWe retrospectively reviewed 33 patients (38 hips) with prior pelvic radiation between 2006 and 2016 who underwent primary THA. The mean overall pelvic radiation dose was 6300 cGy with a mean latency period to THA of 5 years. The most common acetabular component was Pinnacle (DePuy Synthes) in 76%. Eight-seven percent of cups were fixed with screws. The mean age at primary THA was 74 years, 76% were male, and the mean body mass index was 30 kg/m². Mean follow-up was 5 years.ResultsThe 10-year survivorship free of revision for aseptic loosening, free of any revision, and free of any reoperation were 100%, 89%, and 89%, respectively, when accounting for death as a competing risk. There were 3 revisions; one each for taper corrosion, recurrent dislocation, and infection. Radiographically, all cups had evidence of osteointegration and none had radiographic evidence of loosening. The mean Harris Hip Score improved from 50 to 84 postoperatively (P < .0001).ConclusionContemporary porous titanium acetabular components with supplemental screws provided excellent implant fixation in patients with prior therapeutic pelvic radiation. At 10 years, 100% of these components were free of revision for aseptic loosening and 100% were radiographically well-fixed.Level of EvidenceLevel IV, Therapeutic.     

The Direct Anterior Approach for Total Hip Arthroplasty for Severe Dysplasia (Crowe III and IV) Provides Satisfactory Medium to Long-Term Outcomes

BackgroundThe direct anterior approach (DAA) is increasingly used for total hip arthroplasty (THA). Although the DAA can reduce pain, recovery time, and dislocations in nondysplastic hips, few studies report its results in patients with severe dysplasia. We aimed to evaluate outcomes of primary THA through the DAA with cup placement at the true acetabulum in hips with severe dysplasia.MethodsWe retrospectively evaluated 23 consecutive patients (29 hips) who underwent THA by DAA for osteoarthritis secondary to Crowe III-IV dysplasia. Surgical procedures were performed on a traction table, and the acetabular cup was placed in the true acetabulum. Patients were assessed clinically (complications, modified Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index, Oxford Hip Score) and radiographically (radiolucencies, subsidence, leg length discrepancies, cup inclination, and cup coverage) at a minimum of 2 years.ResultsOne patient (2 hips) died with original implants (at 13 and 14 years), 3 patients (3 hips) were revised due to wear-induced loosening (at 14, 16, and 18 years), and there were no dislocations or infections. The remaining 19 patients (24 hips) were assessed at 8.4 ± 4.7 years (range 2-20); 2 patients (2 hips) had complications that required reoperation without implant removal. The modified Harris Hip Score improved from 32 ± 9 to 94 ± 7, Western Ontario and McMaster Universities Osteoarthritis Index from 46 ± 18 to 90 ± 7, and Oxford Hip Score was 56 ± 4. Patients were very satisfied (90%) or satisfied (10%). Limb length discrepancy was 2.5 ± 9.0 mm.ConclusionTHA through the DAA with cup placement at the true acetabulum provides satisfactory mid to long-term clinical and radiographic outcomes compared to other approaches for hips with severe dysplasia.Level of EvidenceLevel IV, retrospective cohort study.     

Mid-term results of large diameter heads on cross-linked polyethylene liners in total hip replacement

BackgroundHighly cross-linked polyethylene liners in total hip replacement (THR) have allowed the use of larger diameter femoral heads. Larger heads allow for increased range of motion, decreased implant impingement, and protection against dislocation. The purpose of this study is to assess the clinical and radiographic outcomes of patients with large femoral heads THR at 4 years postop.Materials and methodsStudy includes 28 patients who had a primary THR with a 36 mm larger femoral head were retrospectively for minimum 4 years follow-up. All patients received a cementless acetabular shell and a highly cross-linked polyethylene liner with an inner diameter of 36 mm. The median radiographic follow-up was 4 years (range 2.0–6.0), and patients were assessed clinically by Harris hip score.ResultsThe mean follow-up is minimum 4 years (range 2–6 years) results in all operated patients showed marked improvement in Harris hip score from preoperative mean 49.1 to 89.9 at 4 years or more follow-up. The complications include superficial infection (n = 2). No dislocation, or no osteolysis was seen in the pelvis or proximal femur, and no components failed due to aseptic loosening. There was no evidence of cup migration, screw breakage, or eccentric wear on the liner.ConclusionThe mid-term results in this series of patients with LDH using 36 mm femoral head articulating with highly cross linked polyethylene showed excellent clinical, and radiological results, in terms of, joint restoration that replicates the natural anatomy, optimized range of motion without impingement & reduced opportunity for postoperative dislocation.     

Clinical Outcomes,Metal Ion Levels,Lymphocyte Profiles,and Implant Survival Following Five Different Bearings of Total Hip Arthroplasty: A Mean 10-year Follow-up Study

BackgroundDifferent bearings have been used in total hip arthroplasty (THA), but the long-term performance is still controversial. The purpose of this study was to investigate whether there are differences when comparing THAs with 5 different bearings at a long-term follow-up of more than 10 years.MethodsFrom January 2010 to May 2012, 101 THA patients (134 hips) were divided into metal-on-metal group (MoM, 31 hips), metal-on-polyethylene group (MoP, 23 hips), ceramic-on-metal group (CoM, 21 hips), ceramic-on-ceramic group (CoC, 33 hips), and ceramic-on-polyethylene group (CoP, 26 hips). The mean follow-up period was 10.3 years. The Harris hip score (HSS), Western Ontario and McMaster Universities Osteoarthritis Index scores (WOMAC), range of motion (ROM), blood cell count, and liver-kidney function were measured. Serum and urine metal ion levels were measured using high-resolution inductively coupled plasma-mass spectrometry (ICP-MS) and a blood lymphocytes analysis was counted by flow cytometry.ResultsNo difference was observed in the HSS, WOMAC, ROM, blood cell count, or liver-kidney function among any of the 5 groups. Metal ion levels were significantly elevated in metal-containing bearings. Flow cytometry showed that no differences were found. Revision was performed due to pseudotumor in 3 patients. The implant survival rate was 96.7% and 93.3% for the MoM and CoC groups, which was significantly lower compared with other groups.ConclusionsMetal ion levels were elevated significantly in metal-containing bearings, especially in MoM THA patients. The implant survival rate was significantly lower in CoC and MoM THAs, which was mainly due to pseudotumor formation.Level of EvidenceTherapeutic Level II.     

Midterm Outcomes After Reconstruction of Superolateral Acetabular Defects Using Flying Buttress Porous Tantalum Augments During Revision Total Hip Arthroplasty

BackgroundPorous tantalum augments are versatile tools in reconstructing complex acetabular defects during revision total hip arthroplasty (THA). This study examines the clinical and radiographic outcomes of porous tantalum augments placed in the type I (flying buttress) configuration at two to 17-year follow-up in the largest cohort to-date in the literature.MethodsWe retrospectively analyzed 59 consecutive revision THAs involving the use of flying buttress augments between 2003 and 2018. The mean patient age and follow-up duration were 63.9 ± 11.6 years (range, 35-87) and 8 years (range, 2-17), respectively. The Oxford hip score was used to assess clinical outcome. The modified Moore classification was used to assess acetabular augment and shell osseointegration. Kaplan-Meier survival analysis with 95% confidence interval (CI) was used to assess implant survivorship.ResultsThe mean Oxford hip score improved from 15.9 ± 6.2 preoperatively to 35.0 ± 6.5 at a mean follow-up of eight years (P < .0001). Radiographic assessment using the modified Moore classification demonstrated five signs of osseointegration in 49 hips (83.1%), four signs in six hips (10.2%), three signs in one hip (1.7%), and one sign in one hip (1.7%). Kaplan-Meier analysis demonstrated ten-year survivorship of 88.9% (95% CI 74.4-95.4) with all-cause revision as end point and 94.3% (95% CI 83.1-98.2) with revision for acetabular aseptic loosening as end point.ConclusionTreatment of superolateral acetabular defects during revision THA using porous tantalum augments placed in the type I (flying buttress) configuration provides excellent implant survivorship and favorable clinical outcomes at mid-term follow-up.Level of EvidenceTherapeutic Level IV.     

Primary Total Hip Arthroplasty With Ceramic-On-Ceramic Articulations: Analysis of a Single-Center Series of 1,083 Hips at a Minimum of 10-Year Follow-Up

BackgroundThere are limited long-term results of using ceramic-on-ceramic (CoC) bearings in total hip arthroplasty (THA) in a large number of patient cohorts. The purpose of this study was to evaluate the minimum 10-year clinical and radiological outcomes and survivorship in a single surgeon series of CoC-THA.MethodsAmong the 1,039 patients (1,391 hips) who underwent primary THA at our institution between 2008 and 2011, 49 patients (69 hips) experienced paralysis or death, and 194 patients (239 hips, 19%) were lost to follow-up. The remaining 796 patients (1,083 hips) were assessed at a mean of 11 years (range, 10 to 13 years) using the modified Harris hip score (mHHS), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a questionnaire on articular noises. Survival analysis was used to estimate the survivorship. Radiological evaluation was performed on 869 hips at the final follow-up.ResultsSurvivorship at 11 years was 98.3% for revision or aseptic loosening, and 98.2% for reoperation. At the final follow-up, the mean mHHS and WOMAC scores were 93 (range, 12 to 100) and 14.4 (range, 3 to 66), respectively. There were 131 (12%) hips that experienced squeaking, but no patient required revision. No fracture of the ceramic was observed. Radiological evaluation at the final follow-up revealed that 3 (0.3%) hips exhibited loosening, 2 (0.2%) had femoral osteolysis, 81(9.3%) acquired radiolucencies, and 35 (4%) showed heterotopic ossification.ConclusionThis CoC bearing for THA had a high survivorship and excellent functional outcomes for at least 10 years.     

Comparisons of Different Bearing Surfaces in Cementless Total Hip Arthroplasty: A Systematic Review and Bayesian Network Analysis

BackgroundWe aimed to make comparisons of different bearing surfaces in patients after cementless total hip arthroplasty.MethodsThe network meta-analysis was guided by the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guideline. The primary outcomes were implant survival and Harris hip score (HHS). Secondary outcomes included linear wear rates and serum level of metal ions. Subgroup analyses were performed by: (1) classifying head sizes as small and large; (2) femoral heads as ceramic and metal; and (3) liners as metal, ceramic, polyethylene, highly cross-linked polyethylene (HXP), or vitamin E-infused highly cross-linked polyethylene (HXPE). A total of 64 eligible RCTs with different bearings were assessed. Overall inconsistency and heterogeneity were acceptable.ResultsIn the 10 years follow-up, metal-on-polythene and ceramic-on-polythene bearings with small heads showed higher risk for revisions compared with metal-on-HXP and ceramic-on-HXP bearings with small heads. Similarly, only metal or ceramic-on-polythene bearings with small heads showed inferiority in HHS compared with other bearings. Conventional polyethylene liners showed higher linear wear rates compared with HXP, HXPE, and ceramic liners at 5 and 10 years after surgery, while metal-on-metal and ceramic-on-metal bearings showed higher serum level of cobalt and chromium.ConclusionBearings containing HXP, HXPE, and ceramic liners showed comparable survivorship and hip function at follow-up of 5 and 10 years. Hard-on-hard bearings containing metal had higher serum level of metal ions than others. Bearings containing conventional polyethylene had worse performance in terms of implant survival, hip function, and wear rates.Level of EvidenceLevel I.     

陶瓷对陶瓷与金属对聚乙烯全髋关节置换的10年随访研究

目的 比较陶瓷对陶瓷（ceramic-on-ceramic, COC）与金属对聚乙烯（metal-on-polyethylene, MOP）全髋关节置换的10年随访临床结果。 方法 对114例接受初次THA的患者进行回顾性研究,其中COC组48例（54髋）,MOP组66例（67髋）,比较COC与MOP两种不同摩擦界面假体的术后髋关节功能、翻修率以及不良事件发生率。 结果 末次随访时患者COC组与MOP组术后髋关节Harris评分分别为89.9±7.5和92.3±8.2,无显著性差异（P＞0.05）;COC组1例翻修（翻修时间术后3年）,MOP组4例翻修（翻修时间平均6年）。两者在翻修、脱位、假体破碎、关节异响、无菌性松动、假体周围骨溶解、深部感染、异化骨化发生率的比较,无显著性差异（P＞0.05）。结论 COC与MOP假体均能提供较好的临床疗效,两者在术后髋关节功能及并发症方面疗效相当。     

Anatomic placement of the acetabular implant in cementless total hip arthroplasty does not adversely affect the implant survival and patient satisfaction

ObjectiveThis study aimed to evaluate if the acetabulum's conservative reaming with preservation of the medial acetabular bone and anatomic placement of the acetabular implant in cementless total hip arthroplasty (THA) has any adverse effect on the radiological outcome, long term implant survival and patient satisfaction.Methods106 consecutive patients were identified from a single surgeon practice who underwent cementless THA from 2005 to 2010. Twenty-one were lost to follow up, and five patients died unrelated to THA. Eighty patients were available for the study. The mean follow-up was 8.6 years (range 5.7–11.6). The mean age was 61.9 years. Immediate pre- and postoperative radiographs were reviewed to calculate combined offset (Acetabular offset – AO, plus Femoral offset – FO). Implant failure, aseptic loosening, revision surgery, patient satisfaction and complications were assessed on long-term follow-up.ResultsAcetabular component survival was 100% with no aseptic failure. None of the patients had revision surgery for any cause. The mean difference in the acetabular offset and combined offset postoperatively was within 3 mm. One patient had a dislocation, and one had a prosthetic joint infection (PJI). 95% of the patients in this series would recommend the hip replacement procedure to others, with a mean satisfaction score of 8.7 (range; 1–10).ConclusionConservative acetabular reaming with preservation of medial acetabulum bone with the anatomic placement of the acetabular implant in cementless THA is safe with no adverse effects on implant survival and patient satisfaction. It offers the advantage of preserving the patient's bone stock, which would potentially be of significant advantage to the patient and the surgeon in case of revision arthroplasty.     

Outcome of total hip arthroplasty in patients with failed open reduction and internal fixation of acetabular fractures

BackgroundThe problem of failed acetabulum fracture fixation is increasing due to increased incidence of high-velocity injury and a large number of patients are being operated on in the past few years. Limited evidence is available regarding results of Total hip arthroplasty (THA) in patients with failed acetabulum fracture fixation surgery. We assessed the clinical, radiological and postoperative complications. Besides this, we also evaluated functional outcome and quality of life following THA in failed open reduction and internal fixation of acetabular fractures.MethodThe current retrospective study was performed at the tertiary center from 2015 to 2020. Eighteen patients of failed acetabulum fracture fixation surgery (14 males and 4 females) were included with a mean follow-up period of 2.4 years. Postero-lateral approach was done in all cases. Clinico-radiological outcome, functional outcomes were recorded according to Harris Hip score (HHS) and quality of life was assessed by using the 12-Item Short Form Health Survey (SF-12) score. Postoperative complications were also assessed.ResultsThe age of patients ranged from 20 years to 68 years with a mean age of 44.7 years. 16 of the patients (88.9%) had a united acetabular fracture while 2 of them (11.1%) presented with un-united acetabular fracture. The THA implant was found to be stable in all 18 cases. The Harris Hip score of the study ranged from 82 to 95 with a mean of 89.72 ± 4.24 while the SF-12 score ranged from 40.0 to 49.4 with a mean of 44.29 ± 2.95. Out of 18 cases, 11 (61.1%) returned with excellent outcomes while the rest 7 (38.9%) returned with good outcomes as per Harris Hips score criteria. The correlation and regression analysis shows between HHS and SF-12 was positive and statistically significant (r = 0.592, p = 0.010).ConclusionTHA in patients with failed acetabulum fracture fixation surgery provides a reliable option with satisfactory outcomes along with a better quality of life.     

Wagner Cone Midterm Survivorship and Outcomes

BackgroundTotal hip arthroplasty (THA) in patients with abnormal proximal femoral anatomy requires an individualized treatment approach to prevent complications. Metaphyseal engaging stems in this population risk fracture, size/offset mismatch, and aseptic loosening. The Wagner conical femoral implant is a short diaphyseal engaging femoral stem that could improve treatment success in this difficult patient population.MethodsWe identified 302 consecutive patients undergoing THA using the Wagner cone femoral prosthesis between January 2010 and January 2017. Clinical, radiographic, and patient-reported outcomes were obtained through chart review and radiographic measurements of postoperative X-rays. We used multivariate analysis to determine predictors of poor outcomes. Kaplan-Meier curves were created to demonstrate implant survivorship with reoperation and revision as endpoints. The average follow-up was 3.2 years, with a minimum of 2 years.ResultsThe implant retention survival rate during the 3.2-year study period was 98.7%. The overall reoperation rate was 4.2%, with infection followed by fracture being the most common reasons for reoperation. No patients were revised for aseptic loosening, and no patients were revised for subsidence. The average subsidence was 1.1 mm. The Harris Hip Score improved from 48.6 ± 7.3 (range, 28-64) preoperatively to 86.1 ± 8.5 (range, 66-100) at latest follow-up. The patient-reported satisfaction rate was 98.3%.ConclusionThe Wagner cone femoral prosthesis demonstrated excellent clinical, radiographic, and patient-reported functional outcomes at midterm follow-up. We recommend use of the Wagner cone in THA patients with challenging proximal femoral anatomy, small femoral diameter, or poor metaphyseal bone quality.     

Direct Cementation of Dual Mobility Cups Into the Bony Acetabulum in Primary Total Hip Arthroplasty: Clinical and Radiographic Outcomes at a Minimum 5-Year Follow-Up

BackgroundCemented dual mobility cups (DMCs) are commonly used in combination with acetabular reinforcement devices. Indeed, according to literature, direct cementation of metal-backed acetabular components into the bony acetabulum remains controversial as this technique is potentially associated with increased rates of aseptic loosening. Therefore, this study aimed to evaluate the clinical and radiographic outcomes of DMC cemented into the bony acetabulum in primary total hip arthroplasty (THA).MethodsA total of 49 THA (48 patients, mean age 78 years [range, 51 to 91]) performed with direct cementation of a DMC into the bony acetabulum were prospectively included in our total joint registry and retrospectively reviewed. The clinical outcome was assessed using the Harris hip score (HHS). The radiographic outcome included measurement of component positioning and occurrence and progression of demarcation around the cemented DMC. Complications were reported with a particular attention to cemented fixation failure and aseptic loosening.ResultsAt a 7-year mean follow-up (range, 5 to 8), the pre-to postoperative HHS improved from 47 (range, 30 to 58) to 92 points (range, 80 to 98) (P < .01). Nonprogressive and focalized demarcations were observed in 7 THA (14%). Importantly, no progressive demarcation or DMC aseptic loosening was observed.ConclusionDirect cementation of DMC into the bony acetabulum ensured a stable fixation with no progressive demarcation or aseptic loosening at midterm follow-up. Therefore, this technique can be selectively considered in primary THA, especially in elderly or frail patients to avoid potential mechanical failure of press-fit fixation due to altered bone quality or additional morbidity related to the use of acetabular reinforcement devices.     

Deep Learning Artificial Intelligence Model for Assessment of Hip Dislocation Risk Following Primary Total Hip Arthroplasty From Postoperative Radiographs

BackgroundDislocation is a common complication following total hip arthroplasty (THA), and accounts for a high percentage of subsequent revisions. The purpose of this study is to illustrate the potential of a convolutional neural network model to assess the risk of hip dislocation based on postoperative anteroposterior pelvis radiographs.MethodsWe retrospectively evaluated radiographs for a cohort of 13,970 primary THAs with 374 dislocations over 5 years of follow-up. Overall, 1490 radiographs from dislocated and 91,094 from non-dislocated THAs were included in the analysis. A convolutional neural network object detection model (YOLO-V3) was trained to crop the images by centering on the femoral head. A ResNet18 classifier was trained to predict subsequent hip dislocation from the cropped imaging. The ResNet18 classifier was initialized with ImageNet weights and trained using FastAI (V1.0) running on PyTorch. The training was run for 15 epochs using 10-fold cross validation, data oversampling, and augmentation.ResultsThe hip dislocation classifier achieved the following mean performance (standard deviation): accuracy = 49.5 (4.1%), sensitivity = 89.0 (2.2%), specificity = 48.8 (4.2%), positive predictive value = 3.3 (0.3%), negative predictive value = 99.5 (0.1%), and area under the receiver operating characteristic curve = 76.7 (3.6%). Saliency maps demonstrated that the model placed the greatest emphasis on the femoral head and acetabular component.ConclusionExisting prediction methods fail to identify patients at high risk of dislocation following THA. Our radiographic classifier model has high sensitivity and negative predictive value, and can be combined with clinical risk factor information for rapid assessment of risk for dislocation following THA. The model further suggests radiographic locations which may be important in understanding the etiology of prosthesis dislocation. Importantly, our model is an illustration of the potential of automated imaging artificial intelligence models in orthopedics.Level of EvidenceLevel III.