Clinical and radiological results of the collarless polished tapered stem at 15 years follow-up

Reduced periprosthetic fracture rate for a cemented anatomical versus a tapered polished stem in hip arthroplasty: A 6-year follow-up of a prospective observational cohort study

Purpose

In older patients requiring a hip arthroplasty, the cemented straight collarless polished tapered stems (PTSs) have been linked to an increased risk of periprosthetic femur fractures (PFFs) when compared to anatomically shaped stems (ASs). This study aims to perform a 6-year follow-up of PFF rates and other adverse events of an orthopaedic department's full transition from a cemented PTS to a cemented AS.

Methods

A prospective single-centre cohort study included 1077 patients operated with a cemented hip replacement at Danderyd Hospital, Stockholm, Sweden, between 2012 and 2015. Patients were divided into two groups based on stem design: PTS (n = 543) and AS (n = 534). Outcomes included the PFF rate, periprosthetic joint infection (PJI) and prosthetic dislocation. A Cox proportional hazards model was used to estimate outcomes.

Results

Most patients (77.2%, mean age 82 years) underwent surgery for a hip fracture. The 6-year PFF rate was 4.6% for the PTS group and 0.9% for the AS group. PFF patterns differed between groups, with Vancouver B fractures being more common in the PTS group. The AS group had lower rates of PJIs (3.6% vs. 1.7%) and dislocations (4.4% vs. 1.3%) than the PTS group.

Conclusion

Transitioning from a PTS to an AS could reduce the PFF rate and other adverse events in hip arthroplasty. The findings are relevant for hospitals treating older and frail patients, as the mean age in this study was >80 years. Further research in different settings is warranted to confirm these results.

Level of Evidence

Level II.

Outcomes of conversion total hip arthroplasty following previous hip fracture surgery

Aims

The conversion of previous hip fracture surgery to total hip arthroplasty (CTHA) can be surgically challenging with unpredictable outcomes; reported complication rates vary significantly. This study aimed to establish the medium-term survival and outcomes of CTHA performed following a previous hip fracture surgery.

Methods

All CTHAs performed at our tertiary orthopaedic institution between January 2008 and January 2020 following previous ipsilateral hip fracture surgery were included. Patients were followed up clinically using Oxford Hip Scores (OHS), and radiologically until death or revision surgery. Postoperative complications, radiological implant failure, and indications for revision surgery were reviewed.

Results

A total of 166 patients (167 hips) were included in the study, with a mean age of 71 years (42 to 99). Of these, 113 patients (67.7%) were female. CTHA followed cannulated screw fixation in 75 cases, hemiarthroplasty in 18, dynamic hip screw fixation in 47, and cephalomedullary nail in 27 cases. Patients were followed up for a mean of four years (0.1 to 9.3). During the follow-up period, 32 patients (19.2%) died. Overall, 14 patients (8.4%) suffered a complication of surgery, with intraoperative fractures (4.2%) and dislocations (3.6%) predominating. The survival probability was 96% at 9.53 years in the cemented group and 88% at 9.42 years in the uncemented group (p = 0.317). The median OHS improved from 13 (IQR 7.75 to 21.25) preoperatively to 39 (IQR 31 to 45) postoperatively in the uncemented group, and from 14 (IQR 10.5 to 22) to 38 (IQR 27 to 45) in the cemented group.

Conclusion

This study highlights that CTHA from hip fracture surgery is associated with higher complication rates than conventional THA, but good medium-term results can be achieved. Their classification within the NJR requires review, acknowledging the increased potential for complications.

Post-operative peri-prosthetic fracture rates following the use of cemented polished taper-slip stems for primary total hip arthroplasty: a systematic review

INTRODUCTION

Peri-prosthetic fractures (PPFs) are a serious complication of total hip arthroplasty (THA) associated with significant morbidity, mortality and re-operation similar to the rates seen following femoral neck fractures. When exploring the PPF rates around cemented stems, many studies combine the results of composite beam and taper-slip stems despite their different philosophies. This review looks specifically at PPFs with the use of cemented stems of the taper-slip philosophy to evaluate the demographics, PPF rate and fracture patterns in this patient cohort.

MATERIALS AND METHODS

A systematic search of Embase, Medline and CINAHL databases was performed to seek studies involving the use of cemented, polished, taper-slip stems, reporting on a rate of post-operative PPF and not involving patient cohorts that were exclusively hip fracture or revision arthroplasty.

RESULTS

27 studies reported on 505 PPFs with an average time from primary operation to PPF of 71.2 months (2-301 months). The average age of patients who sustained PPFs was 70.6 years (53.5-82 years) and the majority were female (64.2%). The Vancouver B2 fracture type was most common (39.5%). Open reduction and internal fixation represented the management of choice in 61.2% of PPFs. There was a re-operation rate of 11.4%.

CONCLUSION

This review suggests an association with being older and female, and a greater risk of PPFs secondary to low energy falls in cemented polished taper-slip stems.

Periprosthetic femoral fractures around the original cemented polished triple-tapered C-stem femoral implant: a consecutive series of 500 primary total hip arthroplasties with an average follow-up of 15 years

INTRODUCTION

The true incidence of periprosthetic femoral fracture (PFF) around cemented polished taper-slip implants remains largely unknown. Registries usually only capture PFFs that result in revision, missing those managed non-operatively or treated by open reduction and internal fixation (ORIF). This study reports the long-term rate of PFF with the original triple-tapered C-stem femoral implant.

MATERIALS AND METHODS

A prospective review of a consecutive series of 500 primary total hip arthroplasties (THAs) performed at a single centre between March 2000 and December 2005, with average follow-up of 15 years (12-19 years).

RESULTS

There were 500 consecutive THAs in 455 patients. Seven PFFs (1.4%) occurred in seven patients at an average of 7.9 years (range 2-11.5) from the primary arthroplasty. Five PFFs were managed by ORIF, one Vancouver B3 fracture was revised for a loose implant and one patient was treated non-operatively. Average age at primary operation was 74 years (67-87) and BMI averaged 27.3 (22-31). There was no typical fracture pattern and no statistically significant associations with patient demographics (age, gender, BMI, diagnosis) or prosthetic details (size, offset, alignment, cement mantle, subsidence). Survivorship to the occurrence of PFF was 99% (97.3-99.6%) at 10 years and 97.8% (95.5-99.0%) at 15.

CONCLUSION

A PFF rate of 1.4% at an average follow-up of 15 years represents the true incidence of PFF with the use of the original triple-tapered C-Stem femoral implant, similar to that of published Exeter series (1.85%) but lower than the CPT (3.3%).

A 2-year prospective clinical and bone density evaluation, with a subset undergoing radiostereometric analysis, using the Absolut cemented stem

Background

Total hip arthroplasty (THA) is common though the investigation of new prostheses requires a practical, step‐wise introduction. This study reports the 2‐year clinical results and periprosthetic bone mineral density (BMD) changes, along with a subset undergoing Radiostereometric analysis (RSA), in patients undergoing primary cemented THA using a new highly polished, double tapered, collarless femoral stem (Absolut).

Methods

Between August 2013 and December 2016, 47 patients with a mean age of 74.2 years (range 36–89) underwent 51 THAs with the Absolut. All patients underwent clinical assessment pre‐surgery and at 6 weeks, 3, 12 and 24 months using the Oxford and Harris Hip Scores, as well as Dual Energy X‐ray Absorptiometry (DEXA) to assess BMD within 2–4 weeks post‐surgery, 12 and 24 months. RSA was undertaken in a patient subset (the first n = 30) early post‐surgery (1–2 days) and 3, 12 and 24 months.

Results

All clinical scores significantly improved (p < 0.05). RSA revealed a mean subsidence of 0.78 mm at 3 months, 1.23 mm at 12 months and 1.51 mm at 24 months. Anterior–posterior and medial‐lateral translation was negligible. A significant increase (p = 0.020) in BMD was observed in Gruen zone 1, though no significant changes were observed for any other zone up until 2 years. Two patients acquired an early post‐operative deep vein thrombosis that were treated accordingly and resolved, with no further complications or re‐operations.

Conclusion

The Absolut cemented femoral stem demonstrated good outcomes, BMD changes consistent with sound prosthesis integration and patterns of post‐operative micromotion observed in other successful cemented stems.

Temporal subsidence patterns of cemented polished taper-slip stems: a systematic review

The literature was reviewed to establish the levels of stem subsidence for both double and triple-tapered implants in order to determine whether there were any differences in subsidence levels with regard to the methods of measurement, the magnitude and rate of subsidence and clinical outcomes.

All studies reporting subsidence of polished taper-slip stems were identified. Patient demographics, implant design, radiological findings, details of surgical technique, methods of measurement and levels of subsidence were collected to investigate which factors were related to increased subsidence.

Following application of inclusion and exclusion criteria, 28 papers of relevance were identified. The studies initially recruited 3090 hips with 2099 being available for radiological analysis at final follow-up. Patient age averaged 68 years (42–70), 60.4% were female and the average body mass index (BMI) was 27.4 kg/m² (24.1–29.2).

Mean subsidence at one, two, five and 10 years was 0.97 mm, 1.07 mm, 1.47 mm and 1.61 mm respectively. Although double-tapered stems subsided more than triple-tapered stems at all time points this was not statistically significant (p > 0.05), nor was the method of measurement used (p > 0.05).

We report the levels of subsidence at which clinical outcomes and survivorship remain excellent, but based on the literature it was not possible to determine a threshold of subsidence beyond which failure was more likely.

There were relatively few studies of triple-tapered stems, but given that there were no statistically significant differences, the levels presented in this review can be applied to both double and triple-tapered designs.

Cite this article: EFORT Open Rev 2021;6:331-342. DOI: 10.1302/2058-5241.6.200086

Cemented hemiarthroplasty for femoral neck fracture patients: collarless, polished tapered stem (CPT) versus anatomic matte stem (Lubinus SP2)

BACKGROUND

Cemented hemiarthroplasty is a well-documented treatment for patients with femoral neck fractures (FNFs). However, there are not many cohort studies comparing different types of hemiarthroplasty (HA).

OBJECTIVE

To compare CPT and Lubinus SP2 HA for FNF patients concerning complications and radiological measurements.

METHODS

From January 1, 2013, CPT was introduced instead of Lubinus SP2 as the new cemented HA due to a regional procurement. Data were retrieved 3 years prior and after the introduction. All patient health records were retrospectively reviewed for types of implant, American Society of Anesthesiologists (ASA) score and duration of admission. All X-ray images were analyzed for radiological measurements concerning offset, stem angulation and cement filling. Mortality and major complications within 1 year were retrieved from patient health records as well as the Danish National Patient Registry. Major complications were defined as dislocations, periprosthetic fractures and revisions.

RESULTS

584 cemented HA were included, 300 CPT and 284 with Lubinus SP2. The mean age (SD) was 82 (8.2) years, and there was no baseline difference between the groups concerning age, sex, ASA score and mortality. There were 8.7% major complications for CPT and 9.2% for Lubinus SP2 (p = 0.836). There were, however, seven periprosthetic fractures in the CPT group and one in the Lubinus SP2 group (p = 0.04). In contrast, there were 20 dislocations in the Lubinus SP2 group and 10 in the CPT group (p = 0.042). There was no statistical difference between the stem angulation and periprosthetic fractures (p = 0.824) or major complications (p = 0.602). The Lubinus SP2 had a mean plus 2.7 mm offset postoperatively (p = 0.001), while the CPT had plus 10.6 mm (p < 0.000). The mean (SD) angle of the stems was 1.39 (1.75) degrees for Lubinus SP2 and 2.46 (1.99) for CPT. There was no difference in cementation (p = 0.308).

CONCLUSION

There was no overall statistical difference between the CPT and Lubinus SP2 stem regarding major complications. However, the CPT had a higher prevalence of periprosthetic fractures, while the Lubinus SP2 had a higher dislocation prevalence. The CPT stem had overcorrection of offset and a higher degree of varus positioning.

The bikini incision anterior cemented total hip arthroplasty: Assessment of radiological and clinical outcomes - A mid-term review

INTRODUCTION

There has been an increased interest in minimally invasive direct anterior approach total hip arthroplasty (THA) to provide greater patient satisfaction, improve pain relief, and reduce the duration of hospitalisation. A direct anterior approach hybrid cemented THA, utilising a bikini line incision, can be technically challenging. We aimed to undertake radiological analysis of femoral stem cementation, clinical outcomes, and component survivorship.

METHODS

Over a 5-year period, 215 primary elective bikini anterior THA conducted by a single surgeon were included. All procedures were performed using a cemented collarless polished stem. The operation was performed on a standard operating table. Patients undergoing posterior approach, revision procedures, and fractured neck of femurs were excluded. Post-operative radiographs were analysed for femoral cementation quality using the Barrack grading system. Harris hip scores (HHS) were determined at 6 weeks, 12 weeks, annually thereafter and the difference in HHS was noted.

RESULTS

In total, 215 anterior bikini THA (R = 101, L = 114) were performed in 199 patients (M = 89, F = 110) with a mean age of 77 and mean follow up of 2.9 years (range = 0.5-5). Radiographic analysis of femoral cementation showed 189 femoral stems (88%) were either Barrack A or B cementation grade, suggesting optimal cementation. Lucency in the cement-bone interface occurred mainly in Gruen Zone 1 (43%) and Zone 13(46.9%). At the most recent follow-up (mean 2.9 years), component survivorship was at 99.54% (stem). Significant improvement was noted in Harris hip scores at final follow-up (from 54 preoperatively to 92.7 at 2.9 years postoperatively).

CONCLUSION

Our results suggest that a bikini incision direct anterior approach for total hip arthroplasty can be safely employed to perform cemented femoral stems on a standard operating table.

A Large-Scale Fifteen-Year Minimum Survivorship of a Cementless Triple Tapered Femoral Stem

BACKGROUND

This study reports the long-term outcomes of a metaphyseal fit-and-fill cementless femoral component in total hip arthroplasty (THA) with a follow-up of 15-19 years.

METHODS

We conducted a retrospective review of 376 consecutive THAs (345 patients), using a triple tapered stem performed between 2000 and 2003 with a view to assessing survivorship and radiological and functional outcomes. Images were assessed for initial alignment, terminal osteolysis, or subsidence, while clinical outcomes were assessed using the St Michael's Hip Score.

RESULTS

Forty-five (11.9%) hips were lost to follow-up, 20 (5.31%) had died before our 15-year cutoff follow-up, and 4 (1.06%) had declined follow-up early on, leaving 307 hips (81.64%, 276 patients) available for both clinical and radiological follow-up at a minimum of 15 years (range 15-19). The mean age at the time of operation was 49.6 years (range 19-71) and the cohort included 131 (42.67%) male and 145 (47.23%) female patients. Seven stems (2.28%) were revised: 4 due to periprosthetic fractures, 2 for periprosthetic joint infection, and 1 for adverse reaction to metal debris at the trunnion. The St Michael's Hip Score improved from 14.2 (range 9-23) preoperatively to 22.3 (range 13 to 25) at the last documented follow-up (P = .000). Kaplan-Meier survivorship with stem revision for any reason as the end point was 97.70%. Worst-case scenario Kaplan-Meier survivorship, where all lost to follow-up are considered as failures, was 85.3%. No stem was revised for aseptic loosening.

CONCLUSION

This triple tapered stem in THA shows excellent survivorship beyond a minimum of 15 years.

Postoperative migration of the anatomical and functional anteversion angle following total hip arthroplasty with a well-fixed cemented femoral component with line-to-line implantation

INTRODUCTION

Little is known about the association between well-fixed polished tapered cemented stems (PTCS) implanted by the line-to-line technique and changes of stem migration, or the change of functional anteversion of the femur after total hip arthroplasty (THA).

MATERIALS AND METHODS

This retrospective study included 422 two-stage bilateral primary THAs performed using PTCS implanted by the line-to-line technique. CT scans were made on both the target side (first postoperative CT) and on the contralateral side (second postoperative CT) 1 week postoperatively. The mean follow-up was 7.8 months. CT data for each scan were transferred to 3D template software (Zed hip, Lexi, Japan). The postoperative changes of anatomical stem anteversion (ASA), functional femoral anteversion (FFA), and stem subsidence were evaluated.

RESULTS

A total of 20 THAs with CT scans were available on 3D template software. The ASA and the FFA had migrated - 0.68° ± 0.62° and - 5.5° ± 9.7°, respectively, over the follow-up period. A significant positive correlation was observed between the change of subsidence and ASA (r² = 0.34, p = 0.007), between the FFA on the second postoperative CT and ASA on the first postoperative CT (r² = 0.26, p = 0.02) and between the FFA on the second postoperative CT and FFA on the first postoperative CT (r² = 0.52, p = 0.0003).

CONCLUSION

This study indicates that the change in axial rotation of a PTCS implanted by the line-to-line technique was less than that reported by other studies and the preoperative external rotation contracture was substantially improved after THA.

Vancouver B2 Peri-Prosthetic Fractures in Cemented Femoral Implants can be Treated With Open Reduction and Internal Fixation Alone Without Revision

BACKGROUND

The aim of this study is to assess the outcomes of 52 consecutive Vancouver B2 peri-prosthetic fractures around cemented polished double-tapered stems treated by open reduction and internal fixation in 2 trauma centers in 2 countries.

METHODS

Outcomes included modified Harris Hip Score (mHHS), Harris Pain Score, and return to pre-injury mobility. Fracture healing was assessed; implant subsidence measured and complications including re-operations reported.

RESULTS

No patient was lost to follow-up. Median patient age at operation was 82 years (range 43-98); Harris pain scores showed minimal pain (median 42, range 10-44) at latest follow-up. Median total subsidence at 1 year was 1.1 mm (range 0-5.4), the majority of which occurred within the cement mantle. No subsequent femoral stem revision was required (median 2.9 years, 0-10); however, there were 3 re-operations: 1 re-operation for pre-existing recurrent dislocation involving head liner exchange and 2 for repeat fixation due to metal fatigue. Two additional fractures occurred below the new plating, requiring further plating whilst still retaining the original stems.

CONCLUSION

Anatomical reduction and open reduction and internal fixation of Vancouver B2 peri-prosthetic fractures should be considered as an appropriate treatment solution for frail elderly patients with a peri-prosthetic fracture around cemented polished double-tapered stems.

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.

Substantially higher prevalence of postoperative peri-prosthetic fractures in octogenarians with hip fractures operated with a cemented, polished tapered stem rather than an anatomic stem

Background and purpose - Recent studies have demonstrated a high incidence of postoperative periprosthetic femoral fracture (PPF) in elderly patients treated with 2 commonly used cemented, polished tapered stems. We compared the prevalence and incidence rate of PPF in a consecutive cohort of octagenerians with femoral neck fractures (FNFs) treated with either a collarless, polished tapered (CPT) stem or an anatomic matte stem (Lubinus SP2). Patients and methods - In a multicenter, prospective cohort study, we included 979 hips in patients aged 80 years and above (72% females, median age 86 (80-102) years) with a femoral neck fracture as indication for surgery. 69% of the patients were classified as ASA class 3 or 4. Hip-related complications and repeat surgery were assessed at a median follow-up of 20 (0-24) months postoperatively. Results - 22 hips (2.2%) sustained a PPF at a median of 7 (0-22) months postoperatively; 14 (64%) were Vancouver B2 fractures. 7 of the 22 surgically treated fractures required revision surgery, mainly due to deep infection. The cumulative incidence of PPFs was 3.8% in the CPT group, as compared with 0.2% in the SP2 group (p < 0.001). The risk ratio (RR) was 16 (95% CI: 2-120) using the SP2 group as denominator. Interpretation - The CPT stem was associated with a higher risk of PPF than the SP2 stem. We suggest that the tapered CPT stem should not be used for the treatment of femoral neck fractures in patients over 80 years.

A Cannulated Tri-Tapered Femoral Stem for Total Hip Arthroplasty: Clinical and Radiological Results at Ten Years

We report the ten-year clinical and radiological outcomes of a novel cannulated, tri-tapered femoral stem, used in primary total hip arthroplasty (110 stems in 98 patients). At ten years, two Tri-taper stems had been revised for infection and dislocation. The mean Oxford Hip Score improved from 13.46 pre-operatively, to 37.04. Radiological analysis revealed radiolucent lines in 57 cases, but none exceeded 2 mm thickness. Stem subsidence was identified in 63 cases, with mean distal tip migration of 3.8 mm. Survivorship with revision for aseptic loosening as the end point was 100% at 10 years. Stem survival with revision for any cause was 98.2% (95% CI, 92.9% to 99.5%). The ten-year results of the Tri-taper stem are comparable to other polished, tapered femoral stems.

Triple taper stem design shows promising fixation and bone remodelling characteristics: radiostereometric analysis in a randomised controlled trial

Cemented femoral stems with force closed fixation designs have shown good clinical results despite high early subsidence. A new triple-tapered stem in this category (C-stem AMT) was introduced in 2005. This study compares this new stem with an established stem of similar design (Exeter) in terms of migration (as measured using radiostereometric analysis), peri-prosthetic bone remodelling (measured using dual energy x-ray densitometry, DXA), Oxford Hip Score, and plain radiographs. A total of 70 patients (70 hips) with a mean age of 66 years (53 to 78) were followed for two years. Owing to missing data of miscellaneous reasons, the final analysis represents data from 51 (RSA) and 65 (DXA) patients. Both stems showed a typical pattern of migration: Subsidence and retroversion that primarily occurred during the first three months. C-stem AMT subsided less during the first three months (p = 0.01), before stabilising at a subsidence rate similar to the Exeter stem from years one to two. The rate of migration into retroversion was slightly higher for C-stem AMT during the second year (p = 0.03). Whilst there were slight differences in movement patterns between the stems, the C-stem AMT exhibits good early clinical outcomes and displays a pattern of migration and bone remodelling that predicts good clinical performance.

High risk of early periprosthetic fractures after primary hip arthroplasty in elderly patients using a cemented, tapered, polished stem

BACKGROUND AND PURPOSE

Postoperative periprosthetic femoral fracture (PPF) after hip arthroplasty is associated with considerable morbidity and mortality. We assessed the incidence and characteristics of periprosthetic fractures in a consecutive cohort of elderly patients treated with a cemented, collarless, polished and tapered femoral stem (CPT).

PATIENTS AND METHODS

In this single-center prospective cohort study, we included 1,403 hips in 1,357 patients (mean age 82 (range 52-102) years, 72% women) with primary osteoarthritis (OA) or a femoral neck fracture (FNF) as indication for surgery (367 hips and 1,036 hips, respectively). 64% of patients were ASA class 3 or 4. Hip-related complications and need for repeat surgery were assessed at a mean follow-up time of 4 (1-7) years. A Cox regression analysis was used to evaluate risk factors associated with PPF.

RESULTS

47 hips (3.3%) sustained a periprosthetic fracture at median 7 (2-79) months postoperatively; 41 were comminute Vancouver B2 or complex C-type fractures. The fracture rate was 3.8% for FNF patients and 2.2% for OA patients (hazard ratio (HR) = 4; 95% CI: 1.3-12). Patients > 80 years of age also had a higher risk of fracture (HR = 2; 95% CI: 1.1-4.5).

INTERPRETATION

We found a high incidence of early PPF associated with the CPT stem in this old and frail patient group. A possible explanation may be that the polished tapered stem acts as a wedge, splitting the femur after a direct hip contusion. Our results should be confirmed in larger, registry-based studies, but we advise caution when using this stem for this particular patient group.

Survival outcomes of cemented compared to uncemented stems in primary total hip replacement

Total hip replacement (THR) is a successful and reliable operation for both relieving pain and improving function in patients who are disabled with end stage arthritis. The ageing population is predicted to significantly increase the requirement for THR in patients who have a higher functional demand than those of the past. Uncemented THR was introduced to improve the long term results and in particular the results in younger, higher functioning patients. There has been controversy about the value of uncemented compared to cemented THR although there has been a world-wide trend towards uncemented fixation. Uncemented acetabular fixation has gained wide acceptance, as seen in the increasing number of hybrid THR in joint registries, but there remains debate about the best mode of femoral fixation. In this article we review the history and current world-wide registry data, with an in-depth analysis of the New Zealand Joint Registry, to determine the results of uncemented femoral fixation in an attempt to provide an evidence-based answer as to the value of this form of fixation.

High failure rates of the Spectron EF stem at a minimum of 10 year's follow-up

We prospectively followed 112 hips, undergoing THA with a Spectron EF stem. At mean follow-up of 11.2years, 21 patients had died. We obtained radiological follow-up in 99% and clinical follow-up in 100% of the surviving 91 hips. Fifty-four percent demonstrated osteolysis in at least one Gruen zone. Twenty-two hips required revision for all causes, with a further five stems radiologically loose. With endpoint being stem revision for aseptic loosening or radiological failure, survivorship at 11years was 0.783. We believe the addition of a rougher surface finish has contributed to the high levels of osteolysis and stem failure seen with the Spectron EF.

A 5-8 year retrospective follow-up of the C-stem AMT femoral component: patient reported outcomes and survivorship analysis

We report midterm functional, radiographic and survivorship data for the cemented, triple taper C-stem AMT femoral component from a consecutive cohort of 415 hip arthroplasties in 386 patients at a non-developer centre. Follow-up ranges were from 60 to 99 months, with a mean of 76 months. 32 hips were lost to follow-up. The median OHS was 40, median SF-12 mental component score (MCS) was 50, and median SF-12 physical component score (PCS) was 39. At 99 months follow up, stem survivorship is 96.9% (95% confidence interval (CI) 82.5-99.5), and construct survivorship is 96.0% (95% CI 84.2-99.0). Adverse events such as calcar fracture, greater trochanter fracture and dislocation were rare at <1%. There have been no revisions for aseptic loosening.

Can plate osteosynthesis of periprosthethic femoral fractures cause cement mantle failure around a stable hip stem? A biomechanical analysis

Periprosthetic femoral fractures (PFF) are a serious complication after total hip arthroplasty. Plate fixation with screws perforating the cement mantle is a common treatment option. The study objective was to investigate hip stem stability and cement mantle integrity under dynamic loading. A cemented hip stem was implanted in 17 composite femur models. Nine bone models were osteotomised just distal to the stem and fixed with a polyaxial locking plate the other eight constructs served as the control group. All specimens were tested in a bi-axial material testing machine (100000 cycles). There were no statistically significant differences in axial nor in medial (varus) stem migration. No cement cracks were detected in both groups. Plate fixation of a PFF with a stable, cemented prosthesis did not lead to cement mantle failure in this in vitro study.

Clinical results, radiological findings and survival of a proximally hydroxyapatite-coated hip ABG II stem at a minimum of ten years' follow-up: results of a consecutive multicentre study of 1148 hips in 1053 patients

We report a multicentre prospective consecutive study assessing the long-term outcome of the proximally hydroxyapatite (HA)-coated ABG II monobloc femoral component in a series of 1148 hips in 1053 patients with a mean age at surgery of 64.77 years (22 to 80) at a mean follow-up of 10.84 years (10 to 15.25). At latest follow-up, the mean total Harris hip score was 94.7 points (sd; 6.87; 49 to 100), and the mean Merle d'Aubigné-Postel score was 17.6 points (sd 1.12; 7 to 18). The mean total Engh radiological score score was 21.54 (sd 5.77; 3.5 to 27), with 95.81% of 'confirmed ingrowth', according to Engh's classification. With aseptic loosening or pain as endpoints, three AGB II stems (0.26%) failed, giving a 99.7% survival rate (se 0.002; 95% confidence interval (CI) 0.994 to 1) at 14 years' follow-up. The survival of patients ≤ 50 years of age (99.0% (se 0.011; 95% CI 0.969 to 1)) did not differ significantly from those of patients aged > 50 years (99.8% (se 0.002; 95% CI 0.994 to 1)). This study confirmed the excellent long-term results currently achieved with the ABG II proximally HA-coated monobloc stem. Cite this article: Bone Joint J 2013;95-B:1610-16.

Characterisation of the surface topography, tomography and chemistry of fretting corrosion product found on retrieved polished femoral stems

This study presents the characterisation of the surface topography, tomography and chemistry of fretting corrosion product found on retrieved polished femoral stems. Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FI-IR) were utilised in order to assess the surface morphology of retrieved Metal-on-Metal Total Hip Replacements and surface chemistry of the films found on the surface. Gross slip, plastic deformation and directionality of the surface were extensively seen on the proximal surfaces of the retrievals. A more corrosive phenomenon was observed in the distal regions of the stem, demonstrating a seemingly intergranular attack. Tribochemical reactions were seen to occur within the stem-cement interfaces with tribofilms being observed on the femoral stem and counterpart PMMA bone cement. XPS, TEM-EDX and FT-IR analyses demonstrated that the films present in the stem surfaces were a complex mixture of chromium oxide and amorphous organic material. A comparison between current experimental and clinical literature has been conducted and findings from this study demonstrate that the formation and chemistry of films are drastically influenced by the type of wear or degradation mechanism. Films formed in the stem-cement interface are thought to further influence the biological environment outside the stem-cement interface due to the formation of Cr and O rich films within the interface whilst Co is free to migrate away.

Surgical approach and prosthesis fixation in hip arthroplasty world wide

BACKGROUND

Hip arthroplasty is one of the most common and successful surgical procedures worldwide. Component design and materials as well as surgical techniques constantly evolve. There is no consensus among surgeons regarding the ideal surgical approach and method of fixation.

MATERIALS AND METHODS

292 orthopedic surgeons of 10 subspecialties from 57 countries were surveyed on their choice of surgical approach and prosthesis fixation in hip arthroplasty. Their preferences were analyzed according to country of origin, field of expertise and seniority, and compared to current publications.

RESULTS

The response rate was 95-98 %. Surgeons were split between the posterior approach (45 %) and the direct lateral approach (42 %) followed by the anterior approach (10 %) or other (3 %). North American surgeons favored the posterior approach more often than Europeans (69 % compared to 36 %, P < 0.0001) and surgeons from other countries (69 % compared to 45 %, P = 0.01). Sixty-eight percent of all surgeons routinely used noncemented hip prosthesis while 16 % use cemented and 16 % hybrid fixation. Noncemented fixation was preferred among surgeons from Europe and North America compared to other countries (73 % compared to 55 %, P < 0.05). There were no significant differences based on subspecialty, seniority or the number of years of experience.

CONCLUSIONS

The most common surgical approaches in use in hip arthroplasty are posterior and lateral. Anterior approach is used by a minority of orthopedic surgeons for that purpose. Cementing hip prosthesis is falling out of favor among orthopedic surgeons worldwide. The trend toward un-cemented hip arthroplasty is not well supported in the current literature.

Successful treatment of concomitant ipsilateral intracapsular and extracapsular hip fractures

Femoral neck fractures and intertrochanteric fractures often occur in elderly patients, but simultaneous ipsilateral intra- and extracapsular hip fractures are rare. Either osteosynthesis or femoral head prosthesis is performed, but careful rehabilitation is necessary because of the instability of the fracture, even postoperatively. This article describes a 76-year-old man who fell and sustained concomitant ipsilateral intra- and extracapsular hip fractures. The patient was treated with a femoral head prosthesis with a polished cemented stem combined with locking plate osteosynthesis. Weight-bearing gait was possible 1 day postoperatively, and bone union was achieved at postoperative week 8. The locking plate had excellent angular stability, even when the screw fixation was monocortical, leading to a reduced risk of intraoperative redislocation without disturbing stem insertion. Sufficient fixation was obtained as a result of the molding effect of the cement stem and the tension band function of the plate. These effects collectively made it possible to achieve full weight-bearing gait immediately postoperatively. Although the intramedullary blood circulation was disturbed by the cement, periosteal blood circulation was retained by the virtue of the locking plate, which facilitated early bone union.