Modern proximally tapered uncemented stems can be safely used in Dorr type C femoral bone

Comparative outcomes of cemented versus cementless stems in bipolar hemiarthroplasty for femoral neck fractures

We aimed to compare the clinical and surgical outcomes of cemented vs uncemented bipolar hemiarthroplasty in the treatment of femoral neck fractures in the elderly. Patients (n = 99) without preoperative cardiopulmonary problems undergoing bipolar hemiarthroplasty for femoral neck fracture between August 2015 and February 2019 were randomly divided into cemented (group C) and uncemented (group U) stem fixation groups. Mean operative time, mean intraoperative blood loss, and percentage of intraoperative use of vasopressors, pre- and postoperative activities of daily living (ADL), incidence of postoperative complications, and radiological evaluation of stem alignment were evaluated. A total of 99 patients were included (group C, n = 42; group U, n = 57). Group C had a significantly longer mean operative time (P < .001) and a significantly higher percentage of intraoperative vasopressor use as compared to group U (P < .05). In contrast, the amount of intraoperative blood loss was similar between the 2 groups (P = .30). Likewise, there was no statistically significant difference in pre- and postoperative ADL performance between the groups (P = .70 and .44, respectively). Postoperative computed tomography revealed that stem anteversion was higher in group C than in group U (P < .05). Cemented and uncemented stems were equivalent in terms of blood loss and postoperative complications in patients with femoral neck fractures. Uncemented stem showed advantages in reducing operative time and intraoperative vasopressor administration. Also, fixation method was not investigated in this study.

The cementless taper wedge vs. fit-and-fill stem in primary total hip arthroplasty: risk of stem-related complication differs across Dorr types

INTRODUCTION

The choice between a cementless taper wedge stem and a fit-and-fill stem in total Hip arthroplasty (THA) for various proximal femoral morphological types has not been thoroughly evaluated. This study aimed to compare the risk of stem-related complications between these two stem types in Dorr type A, B, and C femurs.

MATERIALS AND METHODS

From January 2015 through April 2021, we retrospectively reviewed 1995 cementless THA procedures. We stratified all procedures into three groups: Dorr type A (N = 360, 18.0%), B (N = 1489, 74.7%) and C (N = 146, 7.3%). The primary outcome domain was stem-related complications, including stem subsidence ≥ 3 mm, intraoperative fracture, periprosthetic fracture and aseptic stem loosening. We performed multivariate regression analysis to compare the risk of stem-related complication between the two stem types. Other factors included age, sex, body mass index, diagnosis, age-adjusted Charlson comorbidity index, stem alignment and canal fill ratio.

RESULTS

The incidence of stem-related complications in the taper wedge and fit-and-fill stem groups was 4.4% (N = 15) and 6.5% (N = 107), respectively. Fit-and-fill stems showed an increased risk of stem-related complications (aOR: 9.903, 95% CI: 1.567-62.597) only in Dorr type C femurs. No significant difference in risk was observed in Dorr type A and B femurs. Furthermore, the canal fill ratio at the lesser trochanter, 2 cm and 7 cm below the lesser trochanter, did not exhibit an association with stem-related complications in any Dorr type.

CONCLUSIONS

Concerning the risk of stem-related complications, the taper wedge stem was a better choice in Dorr type C femurs. However, there was no difference in risk between the taper wedge stem and fit-and-fill stem in Dorr type A and B femurs.

A high risk of postoperative periprosthetic femoral fracture in Dorr type C femurs: a retrospective cohort study with 10-year follow-up data and a preliminary monochromatic image analysis

BACKGROUND

The authors applied Anatomique Benoist Girard II (ABG II) stems for total hip arthroplasty in some Dorr type C femurs as early attempts. Here, the authors compared the long-term follow-up results between ABG II stems and the 'well-performing' Corail stems and their monochromatic images.

METHODS

Among 3214 primary total hip arthroplasty records, 43 short ABG II stems and 67 standard-length Corail stems implanted in Dorr type C femurs were eligible and enrolled in this retrospective cohort study, with a mean follow-up of 10.3 years. Revision rates, Harris hip scores, and radiologic signs were compared. Spectral CT scans from a representative sample were obtained, and monochromatic images were reconstructed. A quantitative method was developed to measure the volume of the gap around stems. Patient-specific finite element analysis was conducted to investigate the strains.

RESULTS

The revision rate of ABG II stems was significantly higher than that of Corail stems (21 vs. 3%, P <0.05). In the monochromatic images, fewer spot-weld signs (2.2 vs. 3.4, P <0.05) and wider gaps around stems (1.64 cm 3 vs. 0.13 cm 3 , P <0.05) were observed on average in the ABG II group. The mean maximum principal strains of the proximal femurs in the ABG II group were close to the yield strains and significantly larger than those in the Corail group (0.0052 vs. 0.0011, P <0.05).

CONCLUSIONS

There was a high risk of postoperative periprosthetic femoral fracture for ABG II stems in Dorr type C femurs. Monochromatic images provided some insight into the failure mechanism.

LEVEL OF EVIDENCE

III.

High grade femoral stem subsidence in uncemented hip hemiarthroplasty - A radiographic analysis and an early prediction while treating femoral neck fractures

PURPOSE

Femoral component subsidence is a known risk factor affecting almost all hip replacements using a collarless, cement-less stems. High grade subsidence >5mm is functionally limiting to the patient. Early analysis and prediction of this complication on the immediate post-operative radiographs will help surgeons to opt for alternative solutions to mitigate this complication.

METHODS

A retrospective study including 116 patients, who underwent cement-less bipolar hemi-arthroplasties treated from 2020-2022 were included in the study. Body Mass Index (BMI) and pre-operative American Society Anesthesiologist (ASA) score was retrieved from the medical records. Post operative radiographs on postoperative day two, at four weeks and at eight weeks were evaluated. Dorr's score, initial subsidence ratio (ISR) , stem angulation, proximal stem-canal fit (PSCF) ratio, distal stem-canal fit (DSCF) ratio, medial flare modifier (MFM) were recorded.

RESULTS

A total of 18 patients showed subsidence over 5mm on radiographs evaluated at four weeks. The mean high-grade stem subsidence was 13.5mm +/- 2.67. Evaluating their respective postoperative day two radiographs- ISR was >1 in 16 out of 18 patients (89%), PSCF ratio <0.75 in 83% and DSCF ratio <0.5 in 78% patients. All these patients had a neutral/negative MFM. BMI >25 (p<0.05) and ASA >3 (p<0.001) correlated with a higher degree of stem subsidence.

CONCLUSION

A lower BMI and ASA score accompanied by a positive MFM were protective factors against femoral stem subsidence. A higher ISR along with a PSCF ratio <0.75 and DSCF ratio <0.5, were highly predictive of stem subsidence over 5 mm.

Tapered wedge stems decrease early postoperative subsidence following cementless total hip arthroplasty in Dorr type C femurs compared to fit-and-fill stems

Background

To compare the degree of stem subsidence between two different femoral component designs and to determine the risk factors associated with stem subsidence after cementless total hip arthroplasty (THA) in Dorr type C femurs.

Methods

We retrospectively reviewed 104 consecutive hips in 100 patients with Dorr type C proximal femoral morphology who underwent primary cementless THA using a fit-and-fill stem or a tapered wedge femoral stem at our institution between January 2012 and June 2021. A fit-and-fill stem was used in 55 hips and a tapered wedge stem was used in 49 hips. Radiologically, the distance between the apex of the major trochanter and the stem shoulder were measured at three different time points (immediately [0W], one week [1W], and six weeks [6W] after surgery) and the degrees of stem subsidence were assessed by comparing the distance between 0 and 1W, 1W and 6W, and 0W and 6W, respectively.

Results

The mean degree of stem subsidence (0W vs. 1W) was 0.24 mm (standard deviation [SD] 0.36) in the fit-and-fill stem group, and 0.23 mm (SD 0.41) in the tapered wedge stem group. There was no significant difference between the two groups (P = 0.4862). However, the mean degrees of subsidence were significantly higher in the fit-and-fill stem group (1W vs. 6W, 0.38 mm [SD 0.68]; 0W vs. 6W, 0.65 mm [SD 0.87]) than in the tapered wedge stem group (1W vs. 6W, 0.16 mm [SD 0.32]; 0W vs. 6W, 0.24 mm [SD 0.38]) (P < 0.05 for both). In addition, the rates of > 3 mm subsidence (in which instability can be observed) were 18.2% (10 of 55 hips) and 2.0% (1 of 49 hips), respectively. There was also a significant difference between the two stems (P = 0.0091). Multivariate analysis demonstrated that fit-and-fill stem was a risk factor for > 3 mm subsidence after THA in Dorr type C femurs (P = 0.0050).

Conclusion

Our findings suggest that the tapered wedge stem is more suitable for Dorr type C femurs than the fit-and-fill stem to avoid early postoperative subsidence in cementless THA.

Cementless Hip Arthroplasty in Patients with Subchondral Insufficiency Fracture of the Femoral Head

BACKGROUND

Subchondral insufficiency fracture of the femoral head (SIFFH) occurs in elderly patients and might be confused with osteonecrosis of the femoral head (ONFH). Subchondral insufficiency fracture of the femoral head is an insufficiency fracture at the dome of the femoral head and has been known to be associated with osteoporosis, hip dysplasia, and posterior pelvic tilt. This study's aims were to evaluate (1) surgical complications, (2) radiological changes, (3) clinical results, and (4) survivorship of THA in patients with SIFFH.

METHODS

From November 2010 to June 2017, 21 patients (23 hips); 5 men (5 hips) and 16 women (18 hips) underwent cementless THA due to SIFFH at our institution. Their mean age was 71.9 years (range, 57 to 86) at the time of surgery, and mean T-score was -2.2 (range, -4.2 to 0.2). The mean lateral center-edge angle, abduction, and anteversion of the acetabulum were 29.9° (range, 14.8° to 47.5°), 38.5° (range, 31° to 45°), and 20.0° (range, 12° to 25°), respectively. The mean pelvic incidence, lumbar kyphotic angle and posterior pelvic tilt were 56.4° (range, 39° to 79°), 14.7° (range, -34° to 43°), and 13.0° (range, 3° to 34°), respectively.

RESULTS

An intraoperative calcar crack occurred in 1 hip. The mean anteversion and abduction of cup were 29.0° (range, 17° to 43°) and 43.3° (range, 37° to 50°), respectively. One patient sustained a traumatic posterior hip dislocation 2 weeks after the procedure, and was treated with open reduction. At a mean follow-up of 35.4 months (range, 24 to 79 months), no hip had prosthetic loosening or focal osteolysis. At the latest follow-up, the mean modified Harris hip score was 79.1 (range, 60 to 100) points, and mean UCLA activity score was 4.2 (range, 2 to 7) points. The survivorship was 95.7% (95% CI, 94.9% to 100%) at 6 years.

CONCLUSIONS

Cementless THA is a favorable treatment option for SIFFH in elderly patients.

LEVEL OF EVIDENCE

3.

Does femoral morphology and stem alignment influence outcomes of cementless total hip arthroplasty with proximally coated double-tapered titanium stems?

INTRODUCTION

Stem subsidence and thigh pain can cause significant patient dissatisfaction after cementless THA. The purpose of this study was to examine the effect of proximal-femoral morphology and stem alignment on clinical outcomes using a double-tapered, cementless titanium femoral component.

METHODS

We retrospectively reviewed 281 consecutive, primary THAs from 2012 to 2014 with a mean follow-up of 4 years. Preoperative radiographs were used to assess femoral neck shaft angle (FNS), canal flare index (CFI), Dorr classification, and greater trochanter (GT) overhang. Postoperative radiographs were used to determine stem alignment and 6-week follow-up radiographs were used to determine subsidence. Clinical outcomes included thigh pain, leg-length discrepancy (LLD), patient-reported outcome measures (PROMs) and revision surgeries.

RESULTS

271 stems (96%) did not subside (<4 mm) and 10 (4%) showed evidence of subsidence (>4 mm). Subsidence was significantly associated with subsequent revision surgery (p < 0.01). 278 stems (99%) were in neutral alignment and 3 in varus (1%). Alignment did not significantly influence subsidence, thigh pain, LLD, revisions, or PROMs. Femoral morphology measures (FNS, CFI, Dorr classification, and GT overhang) were not significantly associated with stem alignment, subsidence, LLD, or revisions. CFI was significantly associated with intraoperative calcar fractures (p = 0.02). GT overhang was associated with thigh pain (p = 0.03) and FNS was inversely associated with postoperative HOOS scores.

CONCLUSIONS

Subsidence and proximal-femoral morphology are potential sources of postoperative morbidity in certain cementless THA patients. In accordance with prior studies, CFI was identified as a potential risk factor for intraoperative calcar fractures. More research into preoperative femoral morphologies, such as GT overhang and FNS, is warranted as these may contribute to unsatisfactory results related to cementless THA.

Primary total hip arthroplasty using a short bone-conserving stem in young adult osteoporotic patients with Dorr type C femoral bone

BACKGROUND

Dorr type C femoral bone exhibits a wide, stovepipe-shaped femoral canal, and thin cortices in the proximal femur. Dorr C bone combined with severe osteoporosis is an important challenge in primary hip arthroplasty. In this study, we assessed the effects of short metaphyseal fitting cementless stems on preformatted primary total hip arthroplasties in young adult osteoporotic patients with this femoral presentation.

METHODS

A total of 42 hip arthroplasties were performed in 35 young patients (range 20 to 36 years) using a short Tri-lock bone preservation metaphyseal-fitting cementless femoral component between 2012 and 2017. The mean age at surgery of the 27 male (33 hips) and 8 female (9 hips) patients was 27.5 years (range 20.3 to 35.8 years). The mean body mass index (BMI) was 20.2 kg/m2 (range, 16.8-23.2 kg/m2). According to Dorr's criteria, all 42 femora were classified as type C bone and all femurs suffered from severe osteoporosis (Singh index ≤ 3).

RESULTS

The mean follow-up period was 5.5 years (range 3.0 to 8.0 years). The clinical and functional results improved for the Harris hip score, WOMAC, and UCLA activity scores. The Harris Hip score improved from 48.0 ± 8.0 (range 38.0 to 61.0) preoperatively to 87.0 ± 9.0 (range 77.0 to 92.0) at 12 months after surgery and 91.0 ± 8.0 (range 85.0 to 98.0) at final follow-up. The preoperative UCLA activity score was 3.0 ± 0.5 points (range, 1.0-4.0 points), which significantly improved to 7.5 ± 0.7 points (range 6.0 to 8.0 points) at the final follow-up. No patient exhibited thigh pain at the final follow-up. The mean stem-to-canal fill percentages were 97% ± 2.1% (anteroposterior view at midstem). For stem alignment, 40 hips (95.2%) of the femoral stem were positioned neutrally to 3° of varus with reference to the femoral shaft axis. The remaining two were positioned at 4° varus to 4° valgus. Radiographic evaluation showed good osteointegration of the implants in follow-up.

CONCLUSIONS

Based on the tapered-wedge design and proximal porous coating, the shortened tapered conventional stem can achieve reliable stability through neck filling and metaphyseal fixation, which does not depend on the isthmus hoop stress. This stem was suitable in severe osteoporotic patients with type C bones in young adults who presented with a correspondingly straightened femoral canal with a wide isthmus and thin cortex.

Risk factors of thigh pain following total hip arthroplasty with short, tapered-wedge stem

PURPOSE

The occurrence of thigh pain following cementless total hip arthroplasty (THA) may be dependent on multiple factors, which may differ with design of the prosthesis. Thus, this study aimed to investigate the frequency of thigh pain following cementless THA using a short, tapered-wedge stem to identify risk factors for thigh pain.

METHODS

This retrospective cohort study analysed 222 joints of patients who underwent THA with a short, tapered-wedge stem. Thigh pain was evaluated using a questionnaire during each follow-up visit, and the clinical and radiographic assessments were compared.

RESULTS

Thigh pain occurred in 37 patients (16.7%) during the follow-up period. The pain started two to 24 months after THA. Multivariate analysis demonstrated that higher University of California, Los Angeles, activity rating (odds ratio 7.2; 95% confidence interval (CI) 3.0-17.2); Dorr type C femoral bone shape (odds ratio 1.5; 95% CI 1.1-2.0); and stem tip-cortical bone contact (odds ratio 8.2; 95% CI 2.3-29.4) were significant risk factors of thigh pain following THA. Post-operatively, cortical hypertrophy at Gruen zone 4 was significantly found in patients with thigh pain (p value = 0.032).

CONCLUSION

Risk factors of pain following THA with short, tapered-wedge stem were high activity level, Dorr type C femoral bone shape, and stem tip contacting the distal bone surface. Moreover, post-operative cortical hypertrophy at the distal stem tip significantly increased the incidence of thigh pain. Therefore, we must pay attention to the aforementioned factors to avoid post-operative thigh pain when using a short, tapered-wedge stem.

Risk factors for iliopsoas impingement after total hip arthroplasty using a collared femoral prosthesis

Background

The relationship between collar design of a femoral component and iliopsoas impingement (IPI) after total hip arthroplasty (THA) is still underrecognized. The purpose of our study was to determine the possible risk factors for IPI related to the femoral component, when using a collared femoral prosthesis.

Methods

A total of 196 consecutive THA patients (206 hips) using a collared femoral prosthesis were reviewed retrospectively after exclusion of the factors related to acetabular component and femoral head. The patients were divided into +IPI and −IPI group according to the presence of IPI. Radiological evaluations were performed including femoral morphology, stem positioning, and collar protrusion length (CPL). Multivariate regression analysis was performed to assess the risk factors for IPI.

Results

At a minimum follow-up of 1 year, IPI was observed in 15 hips (7.3%). Dorr type C proximal femur was found in nine hips (60%) in the +IPI group and in 28 hips in the −IPI group (14.7%, p < 0.001). The mean stem anteversion in the +IPI group was significantly greater than that in the −IPI group (19.1° vs. 15.2°, p < 0.001), as well as the mean CPL (2.6 mm vs. − 0.5 mm, p < 0.001). The increased stem anteversion (OR = 1.745, p = 0.001) and CPL (OR = 13.889, p = 0.001) were potential risk factors for IPI.

Conclusions

The incidence of IPI after THA is higher than expected when using a collared femoral prosthesis. Among the factors related to collared femoral prosthesis, excessively increased stem anteversion and prominent collar protrusion are independent predictors for IPI. In addition, high risk of IPI should be carefully considered in Dorr type C bone, despite that femoral morphology is not a predictive factor.

Level of evidence

Level IV, clinical cohort study

Total hip arthroplasty in patients with osteoporosis

There is a high prevalence of osteoporosis in patients undergoing total hip arthroplasty. There are several clinically relevant questions related to the management of such cases: the effect of ageing; the initial osseointegration of implants, especially when cementless THA is used; the effect of medical osteoporosis treatment on bone-implant interface; the incidence of intraoperative and late periprosthetic fractures, and the long-term survival of both cemented and cementless total hip arthroplasty performed for proximal femoral fractures and hip osteoarthritis. A critical review of the literature is presented in an attempt to draw practical conclusions.

Primary total hip arthroplasty using an uncemented Wagner SL stem in elderly patients with Dorr type C femoral bone

Background

The purpose of this study was to review retrospectively the primary total hip arthroplasties operated upon with the cementless Wagner Self-Locking stem in patients with type C femoral bone.

Methods

Twenty-eight total hip arthroplasties were performed in 25 patients aged ≥ 60 years using a cementless Wagner Self-Locking femoral component between 2006 and 2011. According to Dorr’s criteria, all 28 femora were classified as type C bone. All patients were treated with THA using a cementless Wagner cone prosthesis. Clinical and radiologic evaluations were performed on all patients.

Results

Mean follow-up period was 125 ± 10.5 months (range 96 to 156 months). Average Harris hip score pre-operatively was 46 ± 9 (range 39 to 62) and at the last follow-up was 90 ± 9 (range 83 to 98). The stem to canal fill is calculated as percentages on the operative side at three distinct levels: just below the lesser trochanter, at midstem, and 1 cm above the tip of the component on anteroposterior radiograph. The mean proximal stem-to-canal fill percentages were 97% ± 2.1%, 95% ± 3.5%, and 88% ± 2.6%, respectively (anteroposterior view) and 92% ± 2.2%, 86% ± 1.9%, and 83% ± 2.5%, respectively (lateral view). Radiographic evaluation demonstrated good osteointegration of the implants in the follow-up.

Conclusions

Based on the long-straight cylindrical tapered stem design, the cementless Wagner SL stem can achieve reliable stability by close apposition of the stem and wide stovepipe femoral canal from metaphysis to diaphysis in type C bone.

Subsidence of Hydroxyapatite-Coated Femoral Stem in Dorr Type C Proximal Femoral Morphology

BACKGROUND

Good bone quality and proper proximal femoral morphology are thought to be necessary for tapered design, cementless femoral stems to resist subsidence. Using tapered, cementless stem for patients with stovepipe morphology or Dorr type C is controversial. The purpose of this study is to analyze (1) subsidence of the fully hydroxyapatite (HA)-coated, tapered, cementless stem in different morphology according to Dorr classification, (2) subsidence of the stem related to radiographic canal-fill ratio.

METHODS

The digitized radiographs of 311 consecutive cementless primary total hip arthroplasty with fully HA-coated, tapered stem were retrospectively reviewed. Subsidence and the canal-fill ratio at 4 locations were evaluated postoperatively after a minimum of 2 years of follow-up. The threshold of subsidence >3 mm was considered as a clinically significant migration.

RESULTS

A multivariate regression analysis of subsidence across Dorr type, controlling for age, gender, and intraoperative calcar fracture, demonstrated 0.40 mm (P = .28) and 0.18 mm (P = .51) greater subsidence in Dorr type C and B when compared to Dorr type A. Age, gender, and calcar fracture had no influence on subsidence, whereas greater canal-fill ratio at 2 cm below lesser trochanter resulted in significantly less subsidence (P = .02). Additionally, all variables did not affect the risk of having subsidence >3 mm.

CONCLUSION

The proximal femoral morphology has no statistically significant effect on the subsidence of fully HA-coated stem. Therefore, this stem type might be a viable option for Dorr type C. Increasing the canal-fill ratio at metadiaphyseal junction may ensure the stability of the stem.

Increased Persistent Mid-Thigh Pain After Short-Stem Compared With Wedge-Shaped Straight-Stem Uncemented Total Hip Arthroplasty at Medium-Term Follow-Up: A Randomized Double-Blinded Cross-Sectional Study

BACKGROUND

Femoral prosthesis design may impact the frequency of mid-thigh pain. We compared current, incidental, and persistent mid-thigh pain between the short-stem, Collum Femoris femur prosthesis, and the wedge shaped straight-stem, Zweymüller femur prosthesis and studied the associations between demographics, radiographic measurements, and mid-thigh pain.

METHODS

We contacted patients from a randomized controlled trial who underwent uncemented total hip arthroplasty (THA) for hip osteoarthritis at a mean follow-up of 44 months (range 24-64 months). Patients were specifically assessed for current (during assessment), incidental (any time postoperatively for >1 week) mid-thigh pain, and persistent (any time postoperatively for >2 years) mid-thigh pain. Furthermore, we used regression analysis to study associations between demographics, radiographic measurements, and mid-thigh pain.

RESULTS

One hundred forty of 150 patients (93%) responded to our assessment. Mean age at the time of operation was 62 years (±7.0). Current mid-thigh pain occurred in 16 patients (23%) in the Collum Femoris Preserving (CFP) group compared with 10 patients (14%) in the Zweymüller group (P = .192). Incidental mid-thigh pain occurred in 24 patients (34%) in the CFP group compared with 15 patients (21%) in the Zweymüller group (P = .090). Persistent mid-thigh pain was found in 13 patients (19%) in the CFP group compared with five patients (7%) in the Zweymüller group (P = .043). Varus malalignment (odds ratio 1.819 [95% confidence interval 1.034-3.200]) and leg lengthening (odds ratio 1.107 per cm lengthening [95% confidence interval 1.026-1.195]) showed significant associations with mid-thigh pain.

CONCLUSIONS

We found more persistent mid-thigh pain after short-stem uncemented THA compared to wedge-shaped straight-stem uncemented THA during medium-term follow-up. Varus malalignment and leg lengthening were associated with mid-thigh pain.

Does Proximally Coated Single-Wedge Cementless Stem Work Well in Dorr Type C Femurs? Minimum 10-year Followup

BACKGROUND

Total hip arthroplasty (THA) with a proximally coated single-wedge (PSW) cementless stem had been generally considered not to be suitable for Dorr Type C femurs. This study compares the long term outcomes of PSW stem according to the type of proximal femoral geometry.

MATERIALS AND METHODS

307 primary THAs in 247 patients were performed with PSW cementless stem and followed up for over 10 years in this retrospective study. According to Dorr's criteria, 89 femurs were classified as Type A, 156 as Type B, and 62 as Type C. They were followed up for an average of 13.2 years (range 10.0-17.3 years). All the hips were evaluated clinically and radiologically.

RESULTS

There was no significant difference in stem survivorship and clinical outcomes including the incidence of thigh pain and the mean postoperative Harris hip score (HHS) in all three groups. No significant differences were observed in osteolysis, pedestal formation, or cortical hypertrophy among the groups. Radiolucent lines <2 mm in thickness in Gruen zone 4 and 7 (P = 0.003 and P = 0.044, respectively), spot-weld (P < 0.001), and stress shielding (P = 0.010) of proximal femur were more pronounced in Dorr C type femora than in Type A or B. Fifty-six intraoperative fractures were identified among 307 hips with PSW stems. The incidence of intraoperative or postoperative femoral fractures was not significantly different among the groups.

CONCLUSIONS

From over a 10-year followup, the PSW stem provided a recommendable option with satisfactory outcomes and excellent stem survivorship regardless of the Dorr type.

Dual offset metaphyseal-filling stems in primary total hip arthroplasty in dysplastic hips after a minimum follow-up of ten years

PURPOSE

The aim of this study was to assess the long-term performance of tapered one-third proximally coated stems in dysplastic hips.

METHODS

This study included 135 dysplasia patients (150 hips) who underwent a total hip arthroplasty and had a minimum follow-up of ten years. Single design tapered stems were used in all patients. There were 112 women (83%) and 23 men (17%) with a mean age of 45 years (23 to 72) at the time of surgery. The mean follow-up was 14.7 years (10 to 16.8). For clinical evaluation, the Harris Hip Score and Merle D'Aubigne scale were used pre-operatively and at the final follow-up. Implant survival was calculated using Kaplan-Meier survivorship analysis, with failure defined as a component revision for any reason.

RESULTS

Overall, one stem was revised for a deep infection. There were no other femoral stem revisions secondary to loosening, wear, periprosthetic fracture, or instability. Radiographic evaluation showed excellent stem osteointegration in all cases. Kaplan-Meier survivorship, with stem revision for any reason as the end point, was 98% at 14 years (95% confidence interval 92.5 to 99.8).

CONCLUSION

This study demonstrates that a dual offset tapered stem achieved excellent survivorship and stability, as well as good clinical outcome scores with minimal thigh pain and stress shielding in patients with arthritis and developmental dysplasia of the hip; a dual offset tapered stem may be a suitable option for primary total hip arthroplasty in this group.

Primary Total Hip Arthroplasty Using an Uncemented Wagner SL Stem in Elderly Patients With Dorr Type C Femoral Bone

The purpose of this study was to review retrospectively the primary total hip arthroplasties operated upon with the cementless Wagner self-locking stem in patients with Type C femoral bone. Twenty-five total hip arthroplasties were performed in 23 patients aged ≥60 years using a cementless Wagner self-locking femoral component between 2006 and 2011. According to Dorr's criteria, all 25 femora were classified as type C bone. Mean follow-up period was 62 months (range, 47–85 months). Average Harris Hip score preoperatively was 46 ± 9 (range, 39–62) and at the last follow-up was 90 ± 9 (range, 83–98). The mean proximal stem-to-canal fill percentage was 95% ± 3.5% (anteroposterior view) and 90% ± 2.8% (lateral view) and the mean distal canal fill was 93% ± 4.5% (anteroposterior) and 92% ± 3.9% (lateral). Radiographic evaluation demonstrated good osteointegration of the implants in follow-up. Based on the long-straight cylindrical tapered stem design, the cementless Wagner SL stem can achieve reliable stability by close apposition of stem and wide stovepipe femoral canal from metaphysis to diaphysis in Type C bone.

The Synergy cementless femoral stem in primary total hip arthroplasty at a minimum follow-up of 15 years

AIMS

We report on the outcome of the Synergy cementless femoral stem with a minimum follow-up of 15 years (15 to 17).

PATIENTS AND METHODS

A retrospective review was undertaken of a consecutive series of 112 routine primary cementless total hip arthroplasties (THAs) in 102 patients (112 hips). There were 60 female and 42 male patients with a mean age of 61 years (18 to 82) at the time of surgery. A total of 78 hips in the 69 patients remain in situ; nine hips in eight patients died before 15 years, and 16 hips in 16 patients were revised. Clinical outcome scores and radiographs were available for 94 hips in 85 patients.

RESULTS

In all, four stems were revised. One stem was revised for aseptic loosening; two stems because of deep infection; and one because of periprosthetic femoral fracture. There was a significant improvement in all components of the Western Ontario and McMaster Universities Osteoarthritis Index score at the final follow-up (total: p < 0.001, pain: p < 0.001, stiffness: p < 0.001, function: p < 0.001). The mean Harris Hip Scores improved from 47 points (27 to 59) pre-operatively to 89 points (65 to 100) at the latest follow-up (p < 0.001). Kaplan-Meier survivorship, with stem revision for aseptic loosening as the endpoint, was 98.9% at 15 years (95% confidence interval (CI) 96.9 to 100, number at risk at 15 years: 90) and with stem revision for any reason was 95.7% (95% CI 91.7 to 99.8, number at risk at 15 years: 90).

CONCLUSION

The Synergy cementless femoral stem demonstrates excellent survivorship and functional outcomes at 15 years. Cite this article: Bone Joint J 2017;99-B:29-36.

Long-term results of uncemented total hip arthroplasty with the Taperloc femoral component in patients with Dorr type C proximal femoral morphology

Aims

To investigate the longevity of uncemented fixation of a femoral component in total hip arthroplasty (THA) in patients with Dorr type C proximal femoral morphology.

Patients and Methods

A total of 350 consecutive uncemented THA in 320 patients were performed between 1983 and 1987, by a single surgeon using the Taperloc femoral component. The 63 patients (68 hips) with Dorr type C proximal femoral morphology were the focus of this review. The mean age of the patients was 69 years (24 to 88) and mean follow-up was 16.6 years (ten to 29). Survival analysis included eight patients (eight hips) who died without undergoing revision surgery prior to obtaining ten years follow-up. All 55 surviving patients (60 hips) were available for clinical assessment and radiographic review. As a comparator group, the survival and implant fixation in the remaining 282 THAs (257 patients) with Dorr type A and B morphology were evaluated. The mean age of these patients was 52 years (20 to 82).

Results

In the Dorr C patient group the mean Harris hip score improved from 51 points (21 to 69 points) pre-operatively to 89 (74 to 100) at final follow-up. No femoral component was loose by radiological criteria and osteolysis was only identified around two stems (3.3%). There was one revision (1.6%) of a well-fixed femoral component for sepsis at 11 years. The survival of the Taperloc femoral component at 20 years with revision for any reason as the endpoint was 98% (95% confidence interval; 87 to 99). A total of ten (3.5%) of the Dorr A and B patient group of 282 THAs required revision surgery. Only one (0.4%) for aseptic loosening. A total of two hips (1%) were loose by radiographic criteria and osteolysis occurred around 12 hips (4%).

Conclusion

This study demonstrates that excellent fixation can be achieved using the Taperloc stem in patients with Dorr type A and B, and Dorr type C bone. Take home message: The Taperloc stem demonstrated equivalent results in Dorr type A and B and Dorr type C bone. Cite this article: Bone Joint J 2016;98-B:595–600.

Proximally coated cementless bipolar hemiarthroplasty in Dorr type C bone

The current study was conducted to examine the clinical and radiographic outcomes of cementless bipolar arthroplasty in patients who had type C bone at the time of the procedure. A total of 87 patients (105 hips) who had type C femora and had undergone cementless bipolar hemiarthroplasty with a proximally coated cementless prosthesis for the treatment of displaced femoral neck fractures at a single institution were reviewed. Patients included 83 women and 4 men who had a mean age of 84 years (range, 72-100 years) and were followed for a mean of 6 years (range, 2-11 years). Outcomes evaluated included aseptic implant survivorship, surgical complications, Harris Hip scores, and radiographic findings. At final follow-up, there were no revisions for aseptic implant loosening. The overall aseptic implant survivorship was 95%, with 5 patients undergoing revision surgery for aseptic reasons. Three revisions were because of periprosthetic fractures after falls, 1 revision was because of intractable groin pain, and 1 revision was because of recurrent dislocations. The surgical complication rate was 8.5%, which included 3 septic revisions, 2 avulsion fractures of the greater trochanter after falls, 2 superficial wound infections, 1 recurrent dislocation, and 1 wound hematoma. The mean Harris Hip score had improved to 80 points (range, 30-97 points) at final follow-up. Despite generally poor bone quality and medical comorbidities, elderly patients with displaced femoral neck fractures achieved excellent clinical outcomes, with few perioperative complications, through the use of proximally coated cementless bipolar hemiarthroplasty.

Cost comparison of cementless versus cemented hemiarthroplasty for displaced femoral neck fractures

Hip hemiarthroplasties are frequently performed for displaced femoral neck fractures. The purpose of this study was to identify the costs associated with cementless and cemented hemiarthroplasties, compare operative times, and identify complications. The hypothesis was that cementless hemiarthroplasties cost less than cemented hemiarthroplasties, require less operative time, and have fewer perioperative complications. A retrospective review was conducted of 2 surgeons' patients admitted for displaced femoral neck fractures between 2006 and 2010. Group 1 included 45 patients who underwent monopolar hemiarthroplasties with cementless femoral components via a standard posterior approach by a single surgeon. Group 2 included 49 patients who underwent monopolar hemiarthroplasties with cemented femoral components via a modified lateral approach by a single surgeon. Surgical and anesthesia times and the cost of implants and accessories were recorded. The cost for cementless components was $3275.60 (femoral stem, $2800; monopolar head, $400; sleeve, $75.60), whereas the cost of cemented components was $3694.47 (femoral stem, $1800; monopolar head, $400; sleeve, $75.60, 3 Simplex with tobramycin cement packets, $1221; cement mixer/irrigator with tip/centralizer and plug/pressurizer, $197.87), a cost savings of 12.7% ($418.87). Operative time was significantly reduced in group 1 vs group 2 (mean, 32.9 vs 56.1 minutes, respectively; P<.01). Anesthesia time was also significantly reduced in group 1 (mean, 82.3 vs 102.9 minutes, respectively; P<.01). The difference in mean anesthetic times demonstrates an overall cost savings of 18.6%, or $1161.30. No difference in complications was noted between the groups perioperatively. Regional cost variances, vendor-hospital contracts, and surgeons' operative times are factors that may influence cost savings. This study demonstrates significantly lower operative and anesthetic times and observable cost savings with cementless femoral implants.