Cost Analysis of Dual-Mobility Versus Large Femoral Head Constructs in Revision Total Hip Arthroplasty

Background

The purpose of this study is to report healthcare payer costs of dual-mobility (DM) and large femoral head (LFH) constructs in revision total hip arthroplasties (THAs).

Conversion of Hip Hemiarthroplasty to Total Hip Arthroplasty Utilizing a Dual-Mobility Construct Compared With Large Femoral Heads

Background

Conversion of hemiarthroplasty to total hip arthroplasty (THA) has a historically high, up to 20%, postoperative dislocation rate. As such, dual-mobility (DM) constructs are an attractive option to mitigate this complication. We analyzed survivorship free of revision, complications, and clinical outcomes of hemiarthroplasties conversion to THAs utilizing DM constructs compared with large femoral heads (≥36 mm).

No Difference in Dislocation Rates Comparing Large Diameter Jumbo Femoral Heads and Dual-Mobility Bearings in Revision Total Hip Arthroplasty

BackgroundDual-mobility (DM) bearings reduce instability in revision total hip arthroplasty (THA); however, DM bearings are costly and reports of corrosion have recently emerged. Furthermore, no study has compared DM to standard bearings with large diameter femoral heads ≥40-mm. This study’s purpose was to compare postoperative dislocation rates of standard and DM bearings with large femoral heads after revision THA.MethodsA retrospective review of 301 consecutive revision THAs was performed. The mean follow-up was 37.1 months. To isolate the effect of the double articulation, standard and DM bearings with femoral heads ≥40-mm were compared. Outcomes were postoperative dislocation and reoperation within 90 days.ResultsThe cohort consisted of 182 standard bearings and 75 DM bearings. There were no differences in revision indication comparing standard and DM bearings (P = .258). Overall dislocation rate was 8.6% (22 of 257). The dislocation rate was 5.7% for standard bearings with ≥40-mm femoral heads compared with 6.9% in DM bearings with ≥40-mm femoral heads (P = 1.000). In multivariate analysis, lower body mass index (odds ratio 1.72), female sex (odds ratio 2.01), and decreased outer femoral head diameter–to–cup component size ratio (odds ratio 1.64) were predictors of postoperative dislocation regardless of bearing type.ConclusionThis study showed no difference in dislocation rates between standard and DM bearings when comparing similar femoral head diameters of ≥40-mm used in revision THAs. Considering the cost and potential deleterious issues associated with additional interfaces, DM bearings should be used judiciously considering similar results may be achieved with single-articulation bearings using large femoral heads.Level of EvidenceLevel III.     

Results After Total Hip Arthroplasty With a Large Head and Bipolar Arthroplasty in Patients With Displaced Femoral Neck Fractures

The authors studied the short-term outcomes of total hip arthroplasty (THA) performed using large diameter femoral heads or bipolar arthroplasty (BA) in physiologically active elderly patients with displaced intracapsular femoral neck fractures. The THA group included 14 males and 66 females with a mean age of 75.5 years, and the BA group included 16 males and 73 females with a mean age of 77.6 years. Surgical procedures were performed by one surgeon using a modified Hardinge approach. Mean operation times were significantly longer in the THA groups. Pain, mobility, and walking ability scores were significantly better in the THA group than in the BA group. Despite no range of motion limitation during the early postoperative period, no dislocation was encountered in either group. The present study suggests that for displaced femoral neck fractures, THA with a large diameter femoral head results in less pain and better function than BA.     

Standing Versus Supine Radiographs to Evaluate Femoral Head Penetration in the Polyethylene Liner After Total Hip Arthroplasty

The linear penetration rates for ceramic femoral heads on conventional and highly cross-linked polyethylene were measured and compared with radiographs taken in the standing and supine position taken three weeks postoperatively and at final follow-up. Seventy-five patients (83 hips) with conventional polyethylene (group-1) and two hundred and seventy five patients (300 hips) with highly cross-linked polyethylene (group-2) were studied. Follow-up periods were 14.5 years in group-1 and 8.6 years in group-2. The average penetration rates in group-1 were 0.17 mm/year in supine position and 0.18 mm/year in standing position (P < 0.05). On the other hand, the rates in group-2 were 0.03 mm/year and 0.04 mm/year respectively (P < 0.05). Although there were statistical differences between groups, 0.01 mm differences are probably not clinically relevant.     

The Effect of Pelvic Tilt and Femoral Head Size on Hip Range-of-Motion to Impingement

Background

About 50%-70% of dislocators have cups placed within so-called “safe zones.” It has been postulated that factors such as femoral head size and pelvic tilt, obliquity, or rotation may influence postoperative stability. Therefore, we assessed varying degrees of pelvic tilt and head sizes on the range of motion (ROM) to impingement.

Direct Leverage for Reducing the Femoral Head in Total Hip Arthroplasty Without Femoral Shortening Osteotomy for Crowe Type 3 to 4 Dysplasia of the Hip

Background

A number of methods for reduction in high hip dislocation in total hip arthroplasty (THA) are time-consuming and laborious, and require great surgical skills. This study aimed to introduce a new reduction technique to achieve rapid, safe, and easy reduction in high hip dislocation.

Relative Head Size Increase Using an Anatomic Dual Mobility Hip Prosthesis Compared to Traditional Hip Arthroplasty: Impact on Hip Stability

Smaller head sizes and head/cup ratios make cups smaller than 50 mm and larger than 58 mm, more prone to dislocation. Using computer modeling, we compared average head sizes and posterior horizontal dislocation distance (PHDD) in two 78-patient matched cohorts. Cup sizes were small (≤ 50 mm) or large (≥ 58 mm). The control cohort had conventional fixed bearing prostheses, while the experimental cohort had anatomical dual mobility (ADM) hip prostheses. ADM cups have larger average head sizes and PHDD than traditional fixed bearing prostheses by 11.5 mm and 80% for cups ≤ 50 mm, and 16.3 mm and 90% for cups ≥ 58 mm. Larger head sizes and increased head/cup ratio may allow the ADM prosthesis to reduce the incidence of dislocation.     

Conversion Total Hip Arthroplasty After Previous Transtrochanteric Rotational Osteotomy for Osteonecrosis of the Femoral Head

The results of conversion total hip arthroplasty (THA) after failed transtrochanteric rotational osteotomy (TRO) are still controversial. We retrospectively reviewed 18 patients with ONFHs who had been treated previously by TRO and were later converted to THAs (conversion group). We made a matched control group of 18 primary THAs for ONFH done by same hip surgeon (PTHA group). There was an improvement in the Harris hip score and WOMAC score at the final follow-up but the improvement was not statistically significant between the two groups. Only internal rotation was significantly better in the PTHA group than in the conversion group. THA after TRO provides satisfactory clinical and radiological outcomes with no significant increase in perioperative morbidity in comparison with that in the primary THA.     

Cementless Total Hip Arthroplasty With Alumina-on-Highly Cross-Linked Polyethylene Bearing in Young Patients With Femoral Head Osteonecrosis

We asked whether total hip arthroplasties (THAs) using alumina-on-highly cross-linked polyethylene bearing would improve functional activity and reduce aseptic loosening, polyethylene wear, and osteolysis. Consecutive primary THAs were performed in 71 patients (73 hips) who were younger than 50 years (mean age, 45.5 years) with femoral head osteonecrosis. There were 48 men (50 hips) and 23 women (23 hips). Osteolysis was evaluated using radiographs and computed tomographic scanning. The average follow-up was 8.5 years (range, 7-9 years). The mean preoperative Harris hip score was 50.6 points, which improved to 96 points at the final follow-up. Preoperative functional activity was improved significantly at the latest follow-up. The mean polyethylene linear penetration was 0.05 ± 0.02 mm/y and no hip had aseptic loosening or osteolysis.     

Intrapelvic Displacement of a Trial Femoral Head During Total Hip Arthroplasty and a Method to Retrieve It

We describe a technique to retrieve a dislodged femoral trial during total hip arthroplasty. During a revision total hip arthroplasty performed through a direct lateral approach, the femoral trial head was dislodged deep into the pelvis, superior and anterior to the hip joint and behind the anterior pelvic rim. This was retrieved via a posterior approach through the same incision by manipulating the trial head through the pelvis from the anterior to posterior direction. To our knowledge, this technique has not been described previously.     

Revision Total Hip Arthroplasty With a Modular Cementless Femoral Stem

We retrospectively reviewed 123 patients who underwent cementless THA with modular femoral stem designs for revision THA or conversion of failed ORIF and found 75 patients available for analysis. The Harris Hip Score (HHS) improved from 52 ± 14 to 86 ± 11 (P < 0.001). The femoral stem was re-revised in eight patients (11%). The mean time to re-revision was 1.1 years (0.13–2.54). Reasons for re-revision included infection (n = 5, 7%), aseptic loosening (n = 2, 3%) and significant pain (n = 1, 1%). There were no failures of the modular junctions. PC stems had an increased rate of intraoperative fractures (PC 28% vs. STS 9%, P = 0.04). Modular cementless femoral stems provide acceptable mid-term results in revision THA.     

Effect of Femoral Head Size,Subject Weight,and Activity Level on Acetabular Cement Mantle Stress Following Total Hip Arthroplasty

In cases where cemented components are used in total hip arthroplasty, damage, or disruption of the cement mantle can lead to aseptic loosening and joint failure. Currently, the relationship between subject activity level, obesity, and prosthetic femoral head size and the risk of aseptic loosening of the acetabular component in cemented total hip arthroplasty is not well understood. This study aims to provide an insight into this. Finite element models, validated with experimental data, were developed to investigate stresses in the acetabular cement mantle and pelvic bone resulting from the use of three prosthetic femoral head sizes, during a variety of daily activities and one high impact activity (stumbling) for a range of subject body weights. We found that stresses in the superior quadrants of the cortical bone‐cement interface increased with prosthetic head size, patient weight, and activity level. In stumbling, average von Mises stresses (22.4 MPa) exceeded the bone cement yield strength for an obese subject (143 kg) indicating that the cement mantle would fail. Our results support the view that obesity and activity level are potential risk factors for aseptic loosening of the acetabular component and provide insight into the increased risk of joint failure associated with larger prosthetic femoral heads. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1771–1783, 2019     

一期全髋关节置换术治疗双侧股骨头缺血性坏死

目的 探讨一期全髋关节置换术（THA）治疗双侧股骨头缺血性坏死（ANFH）的可行性及疗效.方法 自1999年2月～2004年1月,25例双侧ANFH采用一期THA治疗.年龄34～61岁,平均45.6岁.术前Harris评分平均46分（34～62分）.结果 手术时间4.5～6.0 h,平均5.2 h,术中出血600～1300ml,平均880 ml,术中输血800～1400ml,平均1120 ml.X线平片示假体位置良好.25例术后平均随访16个月,关节功能Harris评分平均83分（78～86分）.结论 应用一期THA治疗双侧ANFH安全且近期疗效满意,值得推广应用.同时应注意把握手术适应证.     

Outcomes of Isolated Head and Liner Exchange Using Large Femoral Heads and Modern Liners in Revision Total Hip Arthroplasty

BackgroundPrevious reports on the outcomes of isolated head and liner exchange in revision total hip arthroplasty have found high rates of instability after these surgeries. Most reports have studied constructs using ≤28 mm femoral heads. The purpose of this study was to determine if modern techniques with the use of larger head sizes can improve the rate of instability after head and liner exchange.MethodsWe identified 138 hips in 132 patients who underwent isolated head and liner exchange for polyethylene wear/osteolysis (57%), acute infection (27%), metallosis (13%), or other (2%). All patients underwent revision with either 32 (23%), 36 (62%), or 40 (15%) mm diameter heads. Cross-linked polyethylene was used in all revisions. Lipped and/or offset liners were used in 104 (75%) hips. Average follow-up was 3.5 (1.0-9.1) years. Statistical analyses were performed with significance set at P < .05.ResultsRevision-free survivorship for any cause was 94.6% and for aseptic causes was 98.2% at 5 years. 11 (8%) hips experienced a complication with 7 (5%) hips requiring additional revision surgery. After revision, 4 (3%) hips experienced dislocation, 5 (4%) hips experienced infection, and 1 (1%) hip was revised for trunnionosis. No demographic or surgical factors significantly affected outcomes.ConclusionOur study shows that isolated head and liner exchange using large femoral heads and modern liners provides for better stability than previous reports. The most common complication was infection. We did not identify specific patient, surgical, or implant factors that reduced the risk of instability or other complication.     

Outcome of Total Hip Arthroplasty for Avascular Necrosis of the Femoral Head in Systemic Lupus Erythematosus

This study evaluated the result of total hip arthroplasty (THA) for avascular necrosis of the femur head (AVNFH) in systemic lupus erythematosus (SLE) patients. Nineteen THAs were performed on 13 patients with SLE. The results of these patients were compared with the results of the control group (19 patients) who had THR due to AVNFH with none-SLE conditions. The Harris hip score increased from a preoperative average of 65.3 points to 94.9 at the most recent follow-up. In the control group, the mean HHS was 67.2 preoperatively and 96.1 postoperatively at the last follow-up. No significant difference was found between SLE patients and non-SLE patients who underwent hip arthroplasty. In conclusion, THA is an acceptable treatment for achieving functional improvement in patients who had SLE and AVNFH.     

Midterm Results of Large Diameter Biolox Forte Ceramic Head on Delta Ceramic Liner Articulation in Total Hip Arthroplasty

Seventy-nine patients (94 hips), who underwent cementless alumina-on-alumina total hip arthroplasty (THA) with the use of a 36-mm delta ceramic liner-on-alumina ceramic femoral head, were followed for an average of 6.5 years (range, 5–7.7 years). All acetabular and femoral components were bone-ingrown and neither pelvic nor femoral osteolysis was identified until the latest follow-up. The survivorship with revision surgery as an endpoint was 97.9% (95% confidence interval = 100%–95%). Ceramic related complications such as fracture and squeaking did not occur in any patient. The mid-term results of cementless THA with this type of ceramic articulation are encouraging.     

Femoral Head Length Impact on Outcomes Following Total Hip Arthroplasty in 36 Millimeter Cobalt Chrome-on-Highly Crosslinked Polyethylene Articulations

BackgroundDespite concerns for corrosion, dislocation, and periprosthetic femur fractures, minimal literature has investigated the effect of adjusting femoral head length on outcomes after primary total hip arthroplasty (THA). Therefore, we aimed to investigate the effect of femoral head length on the risk of any revision and reoperation following cobalt chromium (CoCr)-on-highly crosslinked polyethylene (HXLPE) THAs.MethodsBetween 2004 and 2018, we identified 1,187 primary THAs with CoCr-on-HXLPE articulations using our institutional total joint registry. The mean age at THA was 71 years (range, 19-97), 40% were women, and mean body mass index was 30 (range, 10-68). All THAs using 36 mm diameter femoral heads were included. Neutral (0 mm), positive, or negative femoral head lengths were used in 42, 31, and 27% of the THAs, respectively. Kaplan-Meier survivorship was assessed. The mean follow-up was 7 years (range, 2-16).ResultsThe 10-year survivorships free of any revision or reoperation were 94 and 92%, respectively. A total of 47 revisions were performed, including periprosthetic femur fracture (17), periprosthetic joint infection (8), dislocation (7), aseptic loosening of either component (6), corrosion (4), and other (5). Nonrevision reoperations included wound revision (11), open reduction and internal fixation of periprosthetic femur fracture (4), and abductor repair (2). Multivariable analyses found no significant associations between femoral head length and revision or reoperation.ConclusionAltering femoral head lengths in 36 mm CoCr-on-HXLPE THAs did not affect outcomes. Surgeons should select femoral head lengths that optimize hip stability and center of rotation.Level of EvidenceIII.     

保留股骨颈全髋关节置换的手术体会

目的探讨保留股骨颈的全髋关节置换在临床应用中的手术体会。方法2002年1月至2007年2月,12例13侧因各种原因需行全髋关节置换者接受了保留股骨颈的全髋关节置换,采用Gibson切口,在头下位置将股骨头截断,保留完整的股骨颈。选择合适的外杯,55°外翻角装入。内杯为超高分子聚乙烯,超半径设计保持外翻45°。术前、术后及随访中对患者髋关节功能进行Harris评分,随访时摄X线片以了解假体的位置、松动情况及异位骨化。结果全部患者获得1～4年的随访,13侧人工髋关节临床效果良好。人工髋关节的活动及功能良好,髋关节的Harris评分由术前的平均50分提高到末次随访时的平均91分;影像学检查显示人工髋关节位置良好,假体无松动和下沉。结论保留股骨颈的全髋关节置换术对因各种原因需行全髋关节置换者,是一种良好的选择,主要适用于无骨质疏松且股骨颈完整者。     

A Multivariate Analysis to Predict Total Hip Arthroplasty Dislocation With Preoperative Diagnosis,Surgical Approach,Spinal Pathology,Cup Orientation,and Head Size

BackgroundThere are several risk factors for dislocation after total hip arthroplasty (THA), but few studies include radiographic assessment of implants, with spine pathology and patient characteristics. This study estimates the rate of dislocation by patient gender, age, race/ethnicity, body mass index, Charlson Comorbidity Index, spine pathology, prior spine fusion, levels affected, radiographic Kellgren-Lawrence score of spine osteoarthritis, THA indication, surgical approach, and femoral head size.MethodsSeventy-six primary THA patients between January 2007 and 2020 with a dislocation were matched on age and gender to subjects without a known history of dislocation using a 2:1 allocation. Univariable and multivariable survival models that account for matched strata were used to estimate the rate of dislocation.ResultsMedian follow-up of patients at risk for dislocation was 26.48 months (95% confidence interval [CI] 23.75-36.40). On multivariable analysis, patients with an indication other than primary osteoarthritis were 3.69 (95% CI 2.22-6.13, P < .001) times more likely to dislocate than those with osteoarthritis. Patients with a spine pathology were also nominally more likely to dislocate (hazard ratio 1.76, 95% CI 0.97-3.18, P = .06), and patients receiving a posterior surgical approach were 2.74 (95% CI 1.11-6.76, P = .03) times more likely than those receiving a non-posterior approach to dislocate.ConclusionPatients with THA indication other than primary osteoarthritis and receiving a posterior surgical approach, and to a lesser degree spinal pathology, were identified as affecting the rate of dislocation. After correcting for other variables, femoral head size, cup orientation, and patient factors were not predictive.Level of EvidenceLevel IV, case-control study.