Introduction. Reverse total shoulder arthroplasty (RTSA) is rapidly being adopted as the standard procedure for a growing number of shoulder arthropathies. Though short-term outcomes are promising, mid- and long-term follow-ups present a number of complications – among them, humeral stem and glenosphere component loosening. Though not the primary complication, previously reported aseptic loosening required revision in 100% of cases. As the number of patients undergoing RTSA increases, especially in the younger population, it is important for surgeons to identify and utilize prostheses with stable long-term fixation. It has previously been shown in the hip and knee literature that implant migration in the first two years following surgery is predictive of later failure due to loosening in the 5=10-year postoperative window. The purpose of this study is to, for the first time, evaluate the pattern and total magnitude of implant migration in reverse shoulder arthroplasty using the gold standard imaging technique radiostereometric analysis (RSA). Methods. Forty patients were prospectively randomized to receive either a cemented or press-fit humeral stem, and a glenosphere secured to the glenoid with either autologous bone graft or 3D printed porous titanium for primary reverse total shoulder arthroplasty. Following surgery, participants are imaged using RSA, a calibrated, stereo x-ray technique. Radiographs are acquired at 6 weeks (baseline), 3 months, 6 months, 1 year, and 2 years. Migration of the humeral stem and glenosphere at each time point is compared to baseline. Migration of the prostheses is independently compared between humeral stem fixation groups and glenosphere fixation groups using a two-way repeated measures ANOVA with Tukey's test for multiple comparisons. Results. Follow-ups are ongoing and preliminary results are presented. Significant differences were observed at the 6-month and 1-year time points for superior-inferior translation (p = 0.0067, p = 0.0048), and total three-dimensional translation (p = 0.0011, p = 0.0272) between humeral stems, with press-fit humeral stems subsiding significantly more than cemented stems. Migration between the 6-month and 1-year time points was minimal for both stem fixation groups (less than 0.2 mm). No significant differences were observed along any axis at any time point for the glenosphere fixation groups. Conclusion. There is a trend towards increased subsidence with the use of press-fit stems compared to cemented stems in the first six months postoperatively, as is expected. Both implant fixation techniques demonstrate stability from six months through one year, and this trend is expected through two-year follow-up. Similarly, both glenosphere fixation techniques demonstrate immediate and stable fixation through one year

Abstract. Objectives. Stem malalignment in total hip arthroplasty (THA) has been associated with poor long-term outcomes and increased complications (e.g. periprosthetic femoral fractures). Our understanding of the biomechanical impact of stem alignment in cemented and uncemented THA is still limited. This study aimed to investigate the effect of stem fixation method, stem positioning, and compromised bone stock in THA. Methods. Validated FE models of cemented (C-stem – stainless steel) and uncemented (Corail – titanium) THA were developed to match corresponding experimental model datasets; concordance correlation agreement of 0.78 & 0.88 for cemented & uncemented respectively. Comparison of the aforementioned stems was carried out reflecting decisions made in the current clinical practice. FE models of the implant positioned in varus, valgus, and neutral alignment were then developed and altered to represent five different bone defects according to the Paprosky classification (Type I – Type IIIb). Strain was measured on the femur at 0mm (B1), 40mm (B2), and 80mm (B3) from the lesser trochanter. Results. Cemented constructs had lower strain on the implant neck, and higher overall stiffness and strain on bone compared to uncemented THA. Strain on the bone increased further down the shaft of the femoral diaphysis, and with progressing bone defect severity in all stem alignment cases. Highest strain on the femur was found at B2 in all stem alignment and bone defect models. Varus alignment showed higher overall femoral strain in both fixation methods. Interestingly, in uncemented models, highest strain was shown on femoral bone proximally (B1-B2) in varus alignment, but distally (B3) in neutral alignment. Conclusion. Varus stem alignment showed overall higher strain on femur compared to neutral and valgus. This highlights the crucial role of stem alignment in long term outcomes of THA. Differences between the two stem types should be taken in consideration when interpreting results from this study

Introduction. Porous metaphyseal cones are increasingly used for fixation in revision total knee arthroplasty (RTKA). Both cemented shorter length stems and longer diaphyseal engaging stems are currently utilized with metaphyseal cones with no clear evidence of superiority. The purpose of this study was to evaluate our experience with 3D printed titanium metaphyseal cones with both short cemented and longer cementless stems from a clinical and radiographic perspective. Methods. In total 136 3D printed titanium metaphyseal cones were implanted. The mean patient age was 63 and 48% were female. The mean BMI was 33 and the mean ASA class was 2.5. There were 42 femoral cones in which 28 cemented and 14 cementless stems were utilized. There were 94 tibial cones in which 67 cemented and 27 cementless stems were utilized. The choice for stem fixation was surgeon dependent and in general cones were utilized for AORI type 2 and 3 bone defects on the femur and tibia. The most common fixation scenario was short cemented stems on both the femur and tibia followed by cemented stem fixation on the tibia and cementless fixation on the femur. Clinical data such as revision, complication, and PRO was collected at last follow-up (minimum follow-up 1 year). Radiographic analysis included cone bony ingrowth and coronal and sagittal alignment on long-standing radiographs. Descriptive statistics were used to compare demographics between patients who had malalignment (HKA beyond +/− 3 degrees and flexion/extension beyond +/− 3 degrees). Adjusted logistic regression models were run to assess malalignment risk by stem type. Results. Patient reported outcomes demonstrated modest improvements with Pre-op KOOS improving from 44 pre-op to 59 post -op and PF-CAT improving from 33 to 37 post-op. PROMIS pain scores decreased significantly from 54 to 44 post-op. 36% of patients had malalignment in either the coronal or sagittal plane. Patients with malalignment were more likely to be female (66.7% vs 40.4%, p-value=0.02). After adjusting for age, sex and BMI, there was a significantly increased risk for coronal plane malalignment when both the femur and tibia had cementless compared to cemented stems (odds ratio=5.54, 95%CI=1.15, 26.80). There was no significantly increased risk when comparing patients with mixed stems to patients with cemented stems. Sagittal plane malalignment was more common with short cemented stems although both coronal plane and sagittal plane malalignment with either stem type was not associated with inferior clinical outcome. Overall cone survivorship was excellent with only two cones removed for infection. Conclusion. Metaphyseal titanium cones provide reliable fixation in revision TKA. However, PROs in this complex patient population show only modest improvement consistent with other variables such as co-morbidities and poor baseline physical function. Small cone inner diameter may adversely influence cementless stem position leading to coronal plane malalignment. Short cemented stems are subject to greater sagittal plane malalignment with no apparent influence on clinical outcome

Introduction. Femoral component loosening is one of the most common failure modes in cementless total hip arthroplasty (THA). Patient age, weight, gender, osteopenia, stem design and Dorr-C bone have all been proposed as risk factors for poor fixation and subsequent stem subsidence and poor outcome. With the increased popularity of CT-based assistive technologies in THA, (Stryker MAKO and Corin OPSTM), we sought to develop a technique to predicted femoral stem fixation using pre-operative CT. Methods. Fourteen patients requiring THA were randomly selected from a previous study investigating component alignment. Mean age was 64 (53 to 76), and 57% were female. All patients received pre-operative CT for 3D dynamic templating (OPSTM), and a TriFit stem and Trinity cup (Corin, UK) implanted through a posterior approach. Post-operatively, patients received an immediate CT and AP x-ray prior to leaving the hospital, and a 1-year follow-up x-ray. On both the immediate post-op x-ray and 1-year follow-up x-ray, the known cup diameter was used to scale the image. On both images, the distance between the most superior point of the greater trochanter and the shoulder of the stem was measured. The difference was recorded as stem subsidence. Subsidence greater than 4mm was deemed clinically relevant. The post-operative CT was used to determine the precise three-dimensional placement of the stem immediately after surgery by registering the known 3D implant geometry to the CT. For each patient, the achieved stem position from post-op CT was then virtually implanted back into the pre-operative OPSTM planning software. The software provides a colour map of the bone density at the stem/bone interface using the Hounsfield Units (HU) of each pixel of the CT [Fig. 1]. Blue represents low density bone transitioning through to green and then red (most dense). Results. Mean stem subsidence was 2.1mm (0.2mm to 11.1mm). Two patients had clinically relevant subsidence. The first stem in a 68M subsided 11.1mm. The second in a 58M subsided 5.0mm. Both density colour plots had significant areas of blue (low density bone) around the proximal portion of the stem, with minimal medium/high density fixation when compared to the stems with minimal subsidence. Discussion. Using the Hounsfield units of the CT scan as an indicator for bone density, we were able to predict poor implant fixation and subsequent subsidence in a taper wedge stem. This new technology might have pre-operative value in providing a more quantitative measure of fixation and resultant stem choice. For any figures or tables, please contact the authors directly

We report a prospective study of the use of intramedullary bone blocks to improve the fixation of a matt-finish femoral stem in Charnley low-friction arthroplasties. There were 379 patients (441 hips), but at a minimum follow-up of ten years there were 258 arthroplasties in 221 patients including some which had been revised. The mean age at surgery was 41 years (17 to 51) and the mean follow-up was 13.4 years (1 to 20 including the early revisions). Nine stems (3.5%) had been revised for aseptic loosening, but there were no stem fractures. Survivorship of stems was 99.2% at ten years and 94.35% at 15 and 20 years. We found that the patient’s gender, the position of the stem and the experience of the surgeon all influenced the outcome. Our findings suggest that using our method of stem fixation, follow-up of over 11 years was needed to reveal the effects of endosteal cavitation of the femur, and of over 13 years to assess any divergence between the clinical and the radiological outcomes of stem fixation

This study reports the results of hybrid stem fixation in difficult revision hip arthroplasties where proximal femoral bone stock loss was severe. Twenty-six revision arthroplasties (21 women and 5 men, aged from 58 to 86 years), were performed between 1998 and 2008. The indication for surgery was aseptic loosening. In all cases, stabilization of the stem presented problems because of severe proximal femoral bone stock loss (due to extensive periprosthetic osteolytic defects), or because of iatrogenic defects or surgical procedures (attempts to remove the stem and cement with fenestration or extended osteotomy). The average follow-up was 48 months (range 16 to 120). Primary stability is necessary for the successful definite fixation of a cementless implant by bone. When this was not possible (because of proximal cortical insufficiency), we used a modular distally cemented long stem, bypassing the area of bone defect for at least 6–7 cm. Proximally bone defects were grafted and osteotomy was closed with cerclage wires. Four stems (15%) had an asymptomatic subsidence (3 stems subsided less than 3–4 mm and 1 stem about 15mm). No stem was revised to date. Major complications did not occur. The mean Harris hip score improved from 32 points preoperatively to 82.3 points (at the most recent evaluation). Hybrid fixation offers the advantage of initial and secure stability of the cemented stem on the short term, until stabilization of the entire implant by bone occurs. Thus early subsidence and loosening is avoided and on the long term benefits of the cementless fixation are attained. Our results support the method of hybrid fixation in patients with severe femoral bone loss (and consequently problematic stabilization), when primary stability is needed

Introduction/purpose: Cementless femoral fixation in TKA varies regarding philosophy of design, materials, and surgical technique. This study evaluates autograft enhancement with AML (porocoated) stems. Impaction autograft (head reamings) enhances cortico-cancellous fit in canals of different geometry, preserves bone, decreases potential for stress shielding and seals the stem from wear particles. Materials/methods: Clinical/radiologic evaluation of 110 AML prostheses (proximal/extensive porous-coated) with 4- to 11-year (mean 6.9) follow-up was performed. Demographics included 68 females, 42 males, age 34–90 (mean 66). Diagnoses included OA (86), RA (16), other (8). Key surgical points included: 1) stem matching/sizing to proximal cortical contact; 2) head/neck reaming with acetabular graters; 3) autograft delivery (distal-lateral) prior to partial stem insertion and proximal-medial prior to prosthetic seating. Results: Femoral stem fixation was successful in 98%. Autograft fill was visualized radiographically within the first 6 weeks. Stem fit-fill ratios were .63 proximally and .73 distally, suggesting that most stems were stabilized via cortico-cancellous bone. The 2 fixation failures (1 stem fracture, 1 aseptic loosening) occurred in large males with undersized stems. Radiologic stability was noted in 95%. There were 6 cases of proximal osteolysis secondary to wear without distal extension, and no lucency > 2mm. Mean subsidence was.6mm. There were 10 acetabular failures secondary to wear/loosening and 1 traumatic neck fracture. There were no infections. Conclusion: The technique of impaction autograft using femoral head reamings is a biological (osteoinductive-osteoconductive), practical, and simple treatment method to accommodate and fill femoral canal voids frequently encountered in THA. Large, stiff stems (with distal fixation) can be avoided with less risk of technical problems and long-term bone loss secondary to stress shielding. The technique can be utilized, with variation, in any current cementless femoral stem

In order to improve the fixation of the stem in primary Charnley low-friction arthroplasty, the medullary canal was routinely closed off with a cancellous bone block. A prospective study of 611 consecutive arthroplasties were carried out between 1 and 5 1/2 years (average 2 years and 9 months) after operation. There were two cases of radiological loosening of the stem, both of which could have been avoided. Five other patients showed demarcation of the bone-cement junction at the calcar; two of these are considered to be "at risk" of loosening. There was no evidence of radiological loosening of the stem in 604 cases and the method is recommended for routine use in primary total hip arthroplasty

Aims

Porous metaphyseal cones can be used for fixation in revision total knee arthroplasty (rTKA) and complex TKAs. This metaphyseal fixation has led to some surgeons using shorter cemented stems instead of diaphyseal engaging cementless stems with a potential benefit of ease of obtaining proper alignment without being beholden to the diaphysis. The purpose of this study was to evaluate short term clinical and radiographic outcomes of a series of TKA cases performed using 3D-printed metaphyseal cones.

Aims

To achieve the functional benefits of the direct anterior (DA) approach and the fixation benefits of cemented replacement, this study combined the two techniques posing the following questions: does the limited access of the DA approach adversely affect the cement technique?; and does such a cementing technique reduce the incidence of cementless complications?

Purpose: The purpose of this work was to evaluate the quality of cemented humeral stem fixation. We analysed the incidence and influence of humeral lucent lines and loosening after implantation of a shoulder prosthesis as a function of aetiology (fracture versus scapular osteoarthritis) and glenoid status (total versus partial humeral prosthesis). Material and methods: This retrospective series included 1842 first-intention shoulder prostheses reviewed at mean five years (2–10). We selected patients whose initial diagnosis was fracture of the superior portion of the humerus (n=300) and centred osteoarthritis (n=767). All stems implanted for fracture were cemented. For osteoarthritis, there were 610 total prostheses and 157 simple humeral prostheses: 752 stems were cemented and 15 were implanted without cement. The Constant score and radiographic results (AP and lateral view at least) were noted. Results: For cemented stems, the incidence of radiographic lucent lines and loosening was significantly higher in fractures (40% and 10% respectively) than in centred osteoarthritis (14% and 1%). Lucency and loosening did not influence functional outcome in patients with centred osteoarthritis but had a significantly negative effect on final outcome in fractures. For fractures, the incidence of lucent lines was correlated with migration of the tubercles. For osteoarthritis, there was no difference between total and partial prostheses in terms of loosening, but the functional outcome was significantly better with total prostheses. Conclusion: Fixation of the humeral implant with cement remains the gold standard for shoulder prostheses implanted for centred osteoarthritis. However, cement fixation yields disappointing results for fractures: defective fixation of the humeral stem is correlated with migration of the tubercles. For osteoarthritis, there are not more lucent lines with a total prosthesis which provides the better functional results

The early revision rate in elective Total Hip Arthroplasty (THA) three years after surgery in elderly patients over 80 years is significantly lower for cemented stems in the German Arthroplasty Register (EPRD): cemented 3,1% (3.0 – 3.2) vs. uncemented 4.2% (4.1 – 4.3; p < 0.001). However, the mortality rate in elderly patients is elevated for cemented fixation. This study presents a detailed analysis of the influence of stem type and fixation on revision and mortality rate in this patient cohort.

Elective primary THA cases for primary Coxarthrosis using uncemented cups from the EPRD data base were analysed (n₀= 37,183). Four stem type groups were compared: cementless, cementless with collar, cementless short, and cemented. Stems with at least 300 cases at risk three years after surgery were analysed individually. The reference stem was determined as the stem with the lowest revision rate and at least 1000 cases under surveillance 3 years after surgery (n₃ = 28,637).

The revision rate for cemented stems (2.5% [2.2–1.81] was lower than for uncemented (4.5% [4.2–4.9]; p<0.001) and uncemented short stems (4.2% [3.1–5.7]; p=0.002). The revision rate of uncemented collared stems (2.3% [1.5–3.6]) was similar to cemented stems (p=0.89) and lower than for uncemented stems (p=0.02). One year mortality showed no sig. differences between the groups (p>0.17): cemented 3.2% [2.9–3.6], uncemented 3.4% [3.1–3.7], uncemented short 3.5% [2.5–4.9], uncemented collar 2.0% [1.2–3.2].

“Cementless” and “cementless short” stems should not be used in patients over 80 years due to the higher revision risk. If cementing should be avoided, “cementless collared” stems seem to be a good alternative combined with a tendency for a lower one year mortality rate.

The excellent long-term results for the first-generation Charnley stem may not apply to later versions with flanges. It seems possible that the early design functioned as a taper-slip system, as accepted in the Exeter prosthesis.

Comparison with the requirements for the alternative composite-beam system for the femoral component shows considerable differences that have important implications. These include design, surface finish, cementing technique and the interpretation of radiological signs of loosening.

A distinction should be made between the requirements for the successful use of the two different engineering systems.s

Introduction

The decreased bone mass or local osteoporosis at the proximal femur is often recognized in patients of rheumatoid arthritis (RA). In total hip arthroplasty (THA), the cancellous bone will be lost when rasping technique is applied for the preparation of stem insertion. In addition, cutting or elongation for contracted muscles around the hip joint can be required to insert the stem. To avoid these problems, the non-broaching, non-rasping impaction technique for the stems was applied in THA for the patients with RA. We report clinical and radiographic results of this method.

Background

The acknowledged benefit of the direct anterior (DA) approach is early functional return. Most surgeons in the U.S. use cementless femoral replacement given the negative track record of some cemented designs. However, delayed osseointegration of a femoral stem typically seen in older patients with poor bone quality will delay recovery, diminishing the benefits of the DA approach. Registry studies have shown a higher revision rate and complications in this patient population leading to a renewed interest in cemented fixation.

The calcar femorale is a vertical plate of bone lying deep to the lesser trochanter and is formed as a result of traction of the iliopsoas which separates the femoral cortex into two distinct layers, the calcar femorale and the medial femoral cortex. They fuse together proximally to form the medial femoral neck. A stem placed centrally will abut against the calcar femorale with little or no space for cement. Clearing of the calcar will offer space for a cement layer, which will support the stem proximally on the posterior aspect. We compared two consecutive groups of Charnley low-friction arthroplasties, with and without clearing of the calcar.

In 330 patients who had an arthroplasty without clearing the calcar, there were ten revisions for aseptic loosening of the stem and six other stems were considered ‘definitely loose’, giving a rate of failure of 4.8%. In 111 patients in whom the calcar was cleared there was only one revision for aseptic loosening and no stems were classed as ‘definitely loose’, giving a rate of failure of 0.9%.

Survivorship analysis has again shown the need for long-term follow-up; the differences became clear after ten years but because of the relatively small numbers, statistical analysis is not yet applicable.

We now clear the calcar femorale routinely and advocate optimal access to the medullary canal and insertion of the stem in the area of the piriform fossa.

A leading problem with cementless hip replacement is thigh pain, probably due to some degree of loosening. This is most pronounced during activities such as stair climbing or getting up from a chair. Our study compares the immediate fixation of three stems in widespread clinical use, using a cadaver test simulation in which the femur was horizontal, and cyclic forces acted vertically downward on the prosthetic head with gradual increments of load. We implanted and tested 18 pairs of femurs, making analyses between stem types by right to left comparisons. We found no statistically significant differences in loosening between cementless AML and PCA prostheses, but cemented stems withstood greater loads than uncemented stems by a factor of five or more.

Femoral stress shielding in cementless THA is a potential complication commonly observed in cementless distally loading press-fit stems. Long-term metaphyseal fixation and proximal load transfer is desired. Is routine autologous metaphyseal bone impaction and proximal primary stability an answer to this goal?

This prospective study describes long-term femoral bone remodeling and load transfer in cementless THA at a mean of 17 years (range: 15 to 20 years) in 208 consecutive fully HA-coated stems (Corail). All primary THA were performed by one group of surgeons between 1986 and 1991. The concept of surgical technique included impaction of autologous metaphyseal bone using bland femoral broaches until primary stability was achieved without distal press-fit.

Radiographic evaluation revealed a total of five (2.4%) stems with periprosthetic osteolysis, which were associated with eccentric polyethylene wear. They were either revised or awaiting revision. The remaining 97.6% stems revealed desired proximal load transfer in the metaphysis (52%) or in both metaphysis and diaphysis (48%). Distal stress shielding was not observed and was considered to be related to: impaction of metaphyseal bone, bland broaches, HA coating, and prosthetic design.

Biological autologous bone impaction of the metaphysis provides both primary stem stability and successful longterm osteointegration with the Corail stem after 20 years. The surgical technique of proximal autologous bone impaction rather than extraction of cancellous bone material and the use of a fully HA coated stem without distal press-fit show encouraging longterm results in THA.

Aims. To investigate the effect of polyethylene manufacturing characteristics and irradiation dose on the survival of cemented and reverse hybrid total hip arthroplasties (THAs). Methods. In this registry study, data from the National Joint Registry of England, Wales, Northern Ireland and the Isle of Man (NJR) were linked with manufacturing data supplied by manufacturers. The primary endpoint was revision of any component. Cox proportional hazard regression was a primary analytic approach adjusting for competing risk of death, patient characteristics, head composition, and stem fixation. Results. A total of 290,770 primary THAs were successfully linked with manufacturing characteristics. Overall 4,708 revisions were analyzed, 1,260 of which were due to aseptic loosening. Total radiation dose was identified as a risk factor and included in the Cox model. For statistical modelling of aseptic loosening, THAs were grouped into three categories: G1 (no radiation); G2 ( > 0 to < 5 Mrad); and G3 ( ≥ 5 Mrad). G1 had the worst survivorship. The Cox regression hazard ratio for revision due to aseptic loosening for G2 was 0.7 (95% confidence interval (CI) 0.58 to 0.83), and for G3 0.4 (95% CI 0.30 to 0.53). Male sex and uncemented stem fixation were associated with higher risk of revision and ceramic heads with lower risk. Conclusion. Polyethylene irradiation was associated with reduced risk of revision for aseptic loosening. Radiation doses of ≥ 5 Mrad were associated with a further reduction in risk. Cite this article: Bone Joint Res 2020;9(9):563–571

Aims. Osteoporosis can determine surgical strategy for total hip arthroplasty (THA), and perioperative fracture risk. The aims of this study were to use hip CT to measure femoral bone mineral density (BMD) using CT X-ray absorptiometry (CTXA), determine if systematic evaluation of preoperative femoral BMD with CTXA would improve identification of osteopenia and osteoporosis compared with available preoperative dual-energy X-ray absorptiometry (DXA) analysis, and determine if improved recognition of low BMD would affect the use of cemented stem fixation. Methods. Retrospective chart review of a single-surgeon database identified 78 patients with CTXA performed prior to robotic-assisted THA (raTHA) (Group 1). Group 1 was age- and sex-matched to 78 raTHAs that had a preoperative hip CT but did not have CTXA analysis (Group 2). Clinical demographics, femoral fixation method, CTXA, and DXA data were recorded. Demographic data were similar for both groups. Results. Preoperative femoral BMD was available for 100% of Group 1 patients (CTXA) and 43.6% of Group 2 patients (DXA). CTXA analysis for all Group 1 patients preoperatively identified 13 osteopenic and eight osteoporotic patients for whom there were no available preoperative DXA data. Cemented stem fixation was used with higher frequency in Group 1 versus Group 2 (28.2% vs 14.3%, respectively; p = 0.030), and in all cases where osteoporosis was diagnosed, irrespective of technique (DXA or CTXA). Conclusion. Preoperative hip CT scans which are routinely obtained prior to raTHA can determine bone health, and thus guide femoral fixation strategy. Systematic preoperative evaluation with CTXA resulted in increased recognition of osteopenia and osteoporosis, and contributed to increased use of cemented femoral fixation compared with routine clinical care; in this small study, however, it did not impact short-term periprosthetic fracture risk. Cite this article: Bone Joint J 2023;105-B(3):254–260

Aims. Revision total hip arthroplasty in patients with Vancouver type B3 fractures with Paprosky type IIIA, IIIB, and IV femoral defects are difficult to treat. One option for Paprovsky type IIIB and IV defects involves modular cementless, tapered, revision femoral components in conjunction with distal interlocking screws. The aim of this study was to analyze the rate of reoperations and complications and union of the fracture, subsidence of the stem, mortality, and the clinical outcomes in these patients. Methods. A total of 46 femoral components in patients with Vancouver B3 fractures (23 with Paprosky type IIIA, 19 with type IIIB, and four with type IV defects) in 46 patients were revised with a transfemoral approach using a modular, tapered, cementless revision Revitan curved femoral component with distal cone-in-cone fixation and prospectively followed for a mean of 48.8 months (SD 23.9; 24 to 112). The mean age of the patients was 80.4 years (66 to 100). Additional distal interlocking was also used in 23 fractures in which distal cone-in-cone fixation in the isthmus was < 3 cm. Results. One patient (2.2%) died during the first postoperative year. After six months, 43 patients (93.5%) had osseous, and three had fibrous consolidation of the fracture and the bony flap, 42 (91.3%) had bony ingrowth and four had stable fibrous fixation of the stem. No patient had radiolucency around the interlocking screws and no screw broke. One patient had non-progressive subsidence and two had a dislocation. The mean Harris Hip Score increased from of 57.8 points (SD 7.9) three months postoperatively to 76.1 points (SD 10.7) 24 months postoperatively. Conclusion. The 2° tapered, fluted revision femoral component with distal cone-in-cone-fixation, combined with additional distal interlocking in patients with bony deficiency at the isthmus, led to reproducibly good results in patients with a Vancouver B3 fracture and Paprosky type IIIA, IIIB, and IV defects with regard to union of the fracture, subsidence or loosening of the stem, and clinical outcomes. Cite this article: Bone Joint J 2024;106-B(4):344–351

Aims. This study evaluates risk factors influencing fracture characteristics for postoperative periprosthetic femoral fractures (PFFs) around cemented stems in total hip arthroplasty. Methods. Data were collected for PFF patients admitted to eight UK centres between 25 May 2006 and 1 March 2020. Radiographs were assessed for Unified Classification System (UCS) grade and AO/OTA type. Statistical comparisons investigated relationships by age, gender, and stem fixation philosophy (polished taper-slip (PTS) vs composite beam (CB)). The effect of multiple variables was estimated using multinomial logistic regression to estimate odds ratios (ORs) with 95% confidence intervals (CIs). Surgical treatment (revision vs fixation) was compared by UCS grade and AO/OTA type. Results. A total of 584 cases were included. Median age was 79.1 years (interquartile range 72.0 to 86.0), 312 (53.6%) patients were female, and 495 (85.1%) stems were PTS. The commonest UCS grade was type B1 (278, 47.6%). The most common AO/OTA type was spiral (352, 60.3%). Metaphyseal split fractures occurred only with PTS stems with an incidence of 10.1%. Male sex was associated with a five-fold reduction in odds of a type C fracture (OR 0.22 (95% CI 0.12 to 0.41); p < 0.001) compared to a type B fracture. CB stems were associated with significantly increased odds of transverse fracture (OR 9.51 (95% CI 3.72 to 24.34); p < 0.001) and wedge fracture (OR 3.72 (95% CI 1.16 to 11.95); p = 0.027) compared to PTS stems. Both UCS grade and AO/OTA type differed significantly (p < 0.001 and p = 0.001, respectively) between the revision and fixation groups but a similar proportion of B1 fractures underwent revision compared to fixation (45.3% vs 50.6%). Conclusion. The commonest fracture types are B1 and spiral fractures. PTS stems are exclusively associated with metaphyseal split fractures, but their incidence is low. Males have lower odds of UCS grade C fractures compared to females. CB stems have higher odds of bending type fractures (transverse and wedge) compared to PTS stems. There is considerable variation in practice when treating B1 fractures around cemented stems. Cite this article: Bone Jt Open 2021;2(7):466–475

Introduction. In the United States, cementless femoral fixation remains the dominant mode of fixation for femoral neck fractures, despite strong worldwide registry data that supports cemented fixation. The reason for this discrepancy remains unknown, controversial and often difficult to compare due to multiple variables. The purpose of this study was to evaluate a matched cohort of patients undergoing arthroplasty for femoral neck fractures and assess outcomes of revisions, periprosthetic fractures and mortality. Methods. This is an exact matched cohort study. Cemented fixation cases were exact matched to cementless fixation cases in a 1:1 fashion based on age, sex and Charlson Comorbidity Index (CCI). Outcome variables included: revision for periprosthetic fracture; all cause revision and mortality at any time point; all cause revision and mortality within 1-year and within 90-days. The primary independent variable was femoral fixation (cemented, cementless) and covariates included race (black, white, other), ethnicity (hispanic, non-hispanic), teaching status (minor, major, nonteaching) and bedsize (1–99, 100–399, >=400). Chi-square tests and multivariable logistic regression models were used for statistical analysis. Results. A total of 64,283 femoral neck fractures were evaluated. 17,138 cementless femoral stems were matched exactly to cemented femoral stems based on age, gender and Charleston comorbidity index (CCI). In the multivariate logistic regression analysis, compared to cementless femoral fixation, cemented fixation was associated with a 20% reduction in overall revision (OR 0.796, 0.675–0.939), a 30% reduction in revision at 1 year (OR: 0.709, 0.589–0.854) and a 86% reduction in revision for periprosthetic fracture (OR: 0.144, 0.07–0.294). However, cemented stem fixation was associated with a 23% (OR: 1.33, 1.134–1.338) and 16% (OR: 1.232, 1.134–1.338) increase in mortality at 90 days and 1 year post op respectively. Conclusions. In this exact matched cohort study, risk of early revision and revision for PPFx was dramatically reduced at all time points with the use of cemented stem fixation for elective THA and FNF. However, the increased risk of 90d and 1 year mortality following cemented stem fixation in the elective population warrants further investigation

Aims. The aim of this study was to describe the management and associated outcomes of patients sustaining a femoral hip periprosthetic fracture (PPF) in the UK population. Methods. This was a multicentre retrospective cohort study including adult patients who presented to 27 NHS hospitals with 539 new PPFs between 1 January 2018 and 31 December 2018. Data collected included: management strategy (operative and nonoperative), length of stay, discharge destination, and details of post-treatment outcomes (reoperation, readmission, and 30-day and 12-month mortality). Descriptive analysis by fracture type was performed, and predictors of PPF management and outcomes were assessed using mixed-effects logistic regression. Results. In all, 417 fractures (77%) were managed operatively and 122 (23%) conservatively. The median time to surgery was four days (interquartile range (IQR) 2 to 7). Of those undergoing surgery, 246 (59%) underwent revision and/or fixation and 169 (41%) fixation alone. The surgical strategy used differed by Unified Classification System for PPF type, with the highest rate of revision in B2/B3 fractures (both 77%, 176/228 and 24/31, respectively) and the highest rate of fixation alone in B1- (55/78; 71%) and C-type (49/65; 75%) fractures. Cemented stem fixation (odds ratio (OR) 2.66 (95% confidence interval (CI) 1.42 to 4.99); p = 0.002) and B2/B3 fracture type (OR 7.56 (95% CI 4.14 to 13.78); p < 0.001) were predictors of operative management. The median length of stay was 15 days (IQR 9 to 23), 12-month reoperation rate was 5.6% (n = 30), and 30-day readmission rate was 8.4% (n = 45). The 30-day and 12-month mortality rates were 5.2% (n = 28) and 21.0% (n = 113). Nonoperative treatment, older age, male sex, admission from residential or nursing care, and sustaining the PPF around a revision prosthesis were significant predictors of an increased 12-month mortality. Conclusion. Femoral hip PPFs have mortality, reoperation, and readmission rates comparable with hip fracture patients. However, they have a longer wait for surgery, and surgical treatment is more complex. There is a need to create a national framework for data collection for this heterogeneous group of patients in order to understand the outcomes of different approaches to treatment. Cite this article: Bone Joint J 2022;104-B(8):997–1008

The demand for revision total knee arthroplasty (TKA) has grown significantly in recent years. The two major fixation methods for stems in revision TKA include cemented and ‘hybrid’ fixation. We explore the optimal fixation method using data from recent, well-designed comparative studies. We performed a systematic review of comparative studies published within the last 10 years with a minimum follow-up of 24 months. To allow for missing data, a random-effects meta-analysis of all available cases was performed. The odds ratio (OR) for the relevant outcome was calculated with 95% confidence intervals. The effects of small studies were analyzed using a funnel plot, and asymmetry was assessed using Egger's test. The primary outcome measure was all-cause failure. Secondary outcome measures included all-cause revision, aseptic revision and radiographic failure. There was a significantly lower failure rate for hybrid stems when compared to cemented stems (p = 0.006) (OR 0.61, 95% CI 0.42-0.87). Heterogeneity was 4.3% and insignificant (p = 0.39). There was a trend toward superior hybrid performance for all other outcome measures including all-cause re-revision, aseptic re-revision and radiographic failure. Recent evidence suggests a significantly lower failure rate for hybrid stems in revision TKA. There is also a trend favoring the use of hybrid stems for all outcome variables assessed in this study. This is the first time a significant difference in outcome has been demonstrated through systematic review of these two modes of stem fixation. We therefore recommend the use, where possible, of hybrid stems in revision TKA

Introduction. Patients with FNF may be treated by either total hip arthroplasty (THA) or hemiarthroplasty (HA). Utilizing American Joint Replacement Registry (AJRR) data, we aimed to evaluate outcomes in FNF treatment. Methods. Medicare patients with FNF treated with HA or THA reported to the AJRR database from 2012–2019 and CMS claims data from 2012–2017 were analyzed in this retrospective cohort study. “Early” was defined as less than 90 days from index procedure. A logistic regression model, including index arthroplasty, age, sex, stem fixation method, hospital size. 1. , hospital teaching affiliation. 1. , and Charlson comorbidity index (CCI), was utilized to determine associations between index procedure and revision rates. Results. Of 75,333 FNF procedures analyzed, 82.2% had HA. 8.4% had cemented fixation. 36.9% had cementless fixation. Fixation was unknown for 41,225 (54.7%) patients. 90-day readmissions rates were 1.3% for both cohorts. Both the early revision rate (0.9% HA vs. 1.3% THA, p<0.0001) as well as the overall revision rate (1.5% HA vs. 2.3% THA, p<0.0001) were higher in the THA cohort. The three most common reasons for any revision were instability (26%), infection (21%), and periprosthetic fracture (15%). Higher rates of any revision were associated with cementless fixation (OR=1.37, 95% CI 1.20–1.57) and increased age (OR=0.96, 95% CI 0.96–0.97). THA and increased age were risk factors for early and any revision for instability. Cementless fixation, female sex, and decreased age were associated with lower revision rates for infection. Conclusion. The most common surgical treatment for FNF reported to the AJRR was cementless stem fixation and hemiarthroplasty. The higher revision rates for FNF treatment with THA warrant further investigation. The use of cemented femoral fixation in this patient population may be under-utilized. These data provide a benchmark of US practice for reference and comparison to other practices throughout US and the world

Aims. Metaphyseal cones with cemented stems are frequently used in revision total knee arthroplasty (TKA). However, if the diaphysis has been previously violated, the resultant sclerotic canal can impair cemented stem fixation, which is vital for bone ingrowth into the cone, and long-term fixation. We report the outcomes of our solution to this problem, in which impaction grafting and a cemented stem in the diaphysis is combined with an uncemented metaphyseal cone, for revision TKA in patients with severely compromised bone. Methods. A metaphyseal cone was combined with diaphyseal impaction grafting and cemented stems for 35 revision TKAs. There were two patients with follow-up of less than two years who were excluded, leaving 33 procedures in 32 patients in the study. The mean age of the patients at the time of revision TKA was 67 years (32 to 87); 20 (60%) were male. Patients had undergone a mean of four (1 to 13) previous knee arthroplasty procedures. The indications for revision were aseptic loosening (80%) and two-stage reimplantation for prosthetic joint infection (PJI; 20%). The mean follow-up was four years (2 to 11). Results. Survival free from revision of the cone/impaction grafting construct due to aseptic loosening was 100% at five years. Survival free from any revision of the construct and free from any reoperation were 92% and 73% at five years, respectively. A total of six patients (six TKAs, 17%) required a further revision, four for infection or wound issues, and two for periprosthetic fracture. Radiologically, one unrevised TKA had evidence of loosening which was asymptomatic. In all unrevised TKAs the impacted diaphyseal bone graft appeared to be incorporated radiologically. Conclusion. When presented with a sclerotic diaphysis and substantial metaphyseal bone loss, this technique combining diaphyseal impaction grafting with a metaphyseal cone provided near universal success in relation to implant fixation. Moreover, radiographs revealed incorporation of the bone graft and biological fixation of the cone. While long-term follow-up will be important, this technique provides an excellent option for the management of complex revision TKAs. Cite this article: Bone Joint J 2020;102-B(6 Supple A):116–122

Aims. BoneMaster is a thin electrochemically applied hydroxyapatite (HA) coating for orthopaedic implants that is quickly resorbed during osseointegration. Early stabilization is a surrogacy marker of good survival of femoral stems. The hypothesis of this study was that a BoneMaster coating yields a fast early and lasting fixation of stems. Methods. A total of 53 patients were randomized to be treated using Bi-Metric cementless femoral stems with either only a porous titanium plasma-sprayed coating (P group) or a porous titanium plasma-sprayed coating with an additional BoneMaster coating (PBM group). The patients were examined with radiostereometry until five years after surgery. Results. At three months, the mean total translation (TT) was 0.95 mm (95% confidence interval (CI) 0.68 to 1.22) in the P group and 0.57 mm (95% CI 0.31 to 0.83) in the PBM group (p = 0.047). From two to five years, the TT increased by a mean of 0.14 mm (95% CI 0.03 to 0.25) more in the P group than in the PBM group (p = 0.021). In osteopenic patients (n = 20), the mean TT after three months was 1.61 mm (95% CI 1.03 to 2.20) in the P group and 0.73 mm (95% CI 0.25 to 1.21) in the PBM group (p = 0.023). After 60 months, the mean TT in osteopenic patients was 1.87 mm (95% CI 1.24 to 2.50) in the P group and 0.82 mm (95% CI 0.30 to 1.33) in the PBM group (p = 0.011). Conclusion. There was less early and midterm migration of cementless stems with BoneMaster coating compared with those with only a porous titanium plasma-sprayed coating. Although a BoneMaster coating seems to be important for stem fixation, especially in osteopenic patients, further research is warranted. Cite this article: Bone Joint J 2022;104-B(6):647–656

Our previous work presented at BHS revealed a reduced risk of revision for all reasons in THAs using lipped (asymmetric) liners. Some audience members felt that this finding may be due to unaccounted confounders and the hip surgery community remains sceptical. A fully adjusted Cox model was built after exploratory Kaplan-Meier analyses. The following surgical approaches were included in the analysis: Posterior, Hardinge/anterolateral, Other. The variables included in the final Cox model included: Gender, liner asymmetry, age, head composition, stem fixation method, head diameter, indication for implantation and surgical approach. An additional analysis of the 3 most commonly used polyethylene liners with both a flat and asymmetric version was performed. In the fully adjusted Cox model, the use of a flat liner was associated with increased risk of revision for instability (HR: 1.79, 95%CI: 1.52–2.10) and increased risk of revision for all reasons (HR 1.195, 95%CI: 1.104 – 1.293) when compared to THAs utilising flat liners. This finding was upheld in the product specific analysis. When utilising flat liners, the Hardinge/anterolateral approach was associated with a reduced risk of revision for instability compared to the posterior approach (HR 0.56, 95%CI: 0.446 to 0.706). When an asymmetric liner was used, there was no significant difference in the risk of revision for instability between the Hardinge/anterolateral approach and the posterior approach (HR 0.838, 95%CI: 0.633 – 1.110). The use of polyethylene-based bearings gives the surgeon the option to use asymmetric liners. The reduced risk of revision in THAs with asymmetric liners was seen in the analysis of the complete dataset and in the product specific analysis. Our results demonstrate that the posterior approach, when used with asymmetric XLPE liners, is not associated with a higher risk of revision for instability as historical data suggested

Cemented total hip replacement (THR) provides excellent outcomes and is cost-effective. Polished taper-slip (PTS) stems demonstrate successful results and have overtaken traditional composite-beam (CB) stems. Recent reports indicate they are associated with a higher risk of postoperative periprosthetic femoral fracture (PFF) compared to CB stems. This study evaluates risk factors influencing fracture characteristics around PTS and CB cemented stems. Data were collected for 584 PFF patients admitted to eight UK centres from 25/05/2006-01/03/2020. Radiographs were assessed for Unified Classification System (UCS) grade and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) type. Statistical comparisons investigated relationships by age, gender, and stem fixation philosophy (PTS versus CB). The effect of multiple variables was estimated using multinomial logistic regression to estimate odds ratios (OR) with 95% confidence intervals (CI). Median (IQR) age was 79.1 (72.0–86.0) years, 312 (53.6%) patients were female, and 495 (85.1%) stems were PTS. The commonest UCS grade was type B1 (278, 47.6%). The commonest AO/OTA type was spiral (352, 60.3%). Metaphyseal-split fractures occurred only with PTS stems with an incidence of 10.1%. Male gender was associated with a five-fold reduction in odds of a type C fracture (OR 0.22, 95% CI 0.12 to 0.41, p<0.001) compared to a type B fracture. CB stems were associated with significantly increased odds of transverse fracture (OR 9.51, 95% CI 3.72 to 24.34, p <0.001) and wedge fracture (OR 3.72, 95% CI 1.16 to 11.95, p <0.05) compared to PTS stems. This is the largest study investigating PFF characteristics around cemented stems. The commonest fracture types are B1 and spiral fractures. PTS stems are exclusively associated with metaphyseal-split fractures, but their incidence is low. Males have lower odds of UCS grade C fractures compared to females. CB stems had higher odds of bending type fractures (transverse and wedge) compared to PTS stems. Biomechanical testing is needed for validation and investigation of modifiable factors which may reduce the risk of unstable fracture patterns requiring complex revision surgery over internal fixation

Aims. We have evaluated the survivorship, outcomes, and failures of an interlocking, reconstruction-mode stem-sideplate implant used to preserve the native hip joint and achieve proximal fixation when there is little residual femur during large endoprosthetic reconstruction of the distal femur. Methods. A total of 14 patients underwent primary or revision reconstruction of a large femoral defect with a short remaining proximal femur using an interlocking, reconstruction-mode stem-sideplate for fixation after oncological distal femoral and diaphyseal resections. The implant was attached to a standard endoprosthetic reconstruction system. The implant was attached to a standard endoprosthetic reconstruction system. None of the femoral revisions were amenable to standard cemented or uncemented stem fixation. Patient and disease characteristics, surgical history, final ambulatory status. ,. and Musculoskeletal Tumor Society (MSTS) score were recorded. The percentage of proximal femur remaining was calculated from follow-up radiographs. Results. All 14 at-risk native hip joints were preserved at a mean final follow-up of 6.0 years (SD 3.7), despite a short residual femur, often after proximal osteotomies through the lesser trochanter. Overall, 13 of 14 stems had long-term successful fixation. Eight patients required no reoperation. Three patients required reoperation due to implant-related issues, and three patients required reoperation for wound healing problems or infection. There were no dislocations or fractures. At final follow-up the mean MSTS score was 24.9 (SD 4.1). Nine patients required no ambulation aids, and only one had a Trendelenburg gait. Conclusion. This interlocking, reconstruction-mode stem-sideplate reliably preserves native hip joint anatomy and function after large femoral resection with a short remaining proximal femur, both in the primary and revision setting. This is particularly important for preventing or delaying total femoral arthroplasty in young patients after oncological reconstruction. Hip abductor strength and function could be maintained by this method, and the risk of dislocation eliminated. The success of this technique in this modest series should be verified in a larger collaborative study and will be of interest to revision surgeons and oncologists. Cite this article: Bone Joint J 2021;103-B(2):398–404

Aim. To assess the effect of the bearing surface and head size on the survival of total hip replacements with modern bearing surface combinations. Methods. We combined the NJR dataset with polyethylene manufacturing properties as supplied by the manufacturers to sub-divide polyethylene into conventional (PE) and highly crosslinked (XLPE). Cause specific and overall reasons for revisions were analysed using Kaplan-Meier and multi-variate Cox proportional hazard regression survival analyses. The bearing surface analysis was repeated in patients undergoing THR under the age of 55. Results. A total of 337,786 primary THR cases were included with an associated 5,618 revisions. Head size was grouped in <= 28mm (group A), 32mm (group B) and >=36mm (group C). A Cox regression model adjusted for age, gender, bearing combination and stem fixation was used to provide Hazard Ratios (HR). With Group C as reference, revision for all causes in Group A had a HR 1.07 (95%CI 0.99, 1.15) and in Group B HR 0.92 (0.86, 0.98). In patients <55y of age, with MoP as reference, Hazard Ratio for MoXLPE was 0.77 (0.59, 1.01), CoC 0.64 (0.52, 0.78), CoXLPE 0.61 (0.47, 0.78), CoP 0.50 (0.36, 0.70) and CMoXLPE 0.47 (0.30, 0.76). Conclusion. When combined with modern bearing combinations, the use of femoral heads of 36mm or larger was associated with a decreased cumulative incidence of revision for dislocation and an increased incidence of revision for aseptic loosening. In patients under the age of 55, CMoXLPE performed best at maximum follow up of 11 years

Aims. The goals of this study were to define the risk factors, characteristics, and chronology of fractures in 5417 revision total hip arthroplasties (THAs). . Patients and Methods. From our hospital’s prospectively collected database we identified all patients who had undergone a revision THA between 1969 and 2011 which involved the femoral stem. The patients’ medical records and radiographs were examined and the relevant data extracted. Post-operative periprosthetic fractures were classified using the Vancouver system. A total of 5417 revision THAs were identified. Results. There were 668 intra-operative fractures, giving an incidence of 12%. Fractures were three times more common with uncemented stems (19%) than with cemented stems (6%) (p <  0.001). The incidence of intra-operative femoral fracture varied by uncemented stem type: fully-coated (20%); proximally-coated (19%); modular fluted tapered (16%) (p < 0.05). Most fractures occurred during the insertion of the femoral component (35%). One-third involved the diaphysis and 26% were of the calcar: 69% were undisplaced. There were 281 post-operative fractures of the femur (20-year probability = 11%). There was no difference in risk for cemented and uncemented stems. Post-operative fractures were more common in men < 70 years (p = 0.02). Periprosthetic fractures occurred earlier after uncemented revision of the femoral component, but later after a cemented revision. The most common fracture type was a Vancouver B. 1. (31%). Of all post-operative fractures, 24% underwent open reduction and internal fixation and 15% revision arthroplasty. Conclusion. In revision THA, intra-operative fractures occurred three times more often with an uncemented stem. Many were undisplaced diaphyseal fractures treated with cerclage fixation. . While the risk of post-operative fracture is similar between uncemented and cemented components, they occur at notably different times depending on the type of stem fixation. . Take home message: In revision THA, intra-operative periprosthetic femoral fractures occur three times more often with uncemented stems. Many are non-displaced diaphyseal fractures treated with cerclage fixation. While postoperative fracture risks are equivalent between uncemented and cemented components, they occur at notably different time periods based on stem fixation type. Cite this article: Bone Joint J 2016;98-B:468–74

Instability after TKA can result from ligament imbalance, attenuation of soft tissues, or ligament disruption. Flexion instability has been reported after both CR and PS TKA. However, the clinical manifestations of flexion instability can be quite variable. Symptoms of flexion instability include pain and swelling after activity. Bracing occasionally can be helpful. Revision options to treat flexion instability include tibial insert exchange and revision to increase constraint. However, more favorable results have been reported using implants with varus-valgus constraint. Constrained mechanisms include a varus-valgus constrained PS post or hinge. The constrained post relies on the mechanical function of the post to provide stability which may deform or wear in-vivo leading to recurrent instability if used for a completely deficient collateral ligament. The hinge, which provides more rigid constraint, is indicated for collateral ligament deficiency. However, the additional constraint also results in greater bone-implant interface stresses, which may be mitigated by use of stem fixation to minimise risk of loosening

Introduction. Metaphyseal cones with cemented stems are frequently used in revision total knee arthroplasties (TKAs). However, if the diaphysis has been previously violated (as in revision of a failed stemmed implant), the resultant sclerotic canal can impair cemented stem fixation, which is vital for cone ingrowth and long-term fixation. We report the outcomes of our novel solution to this problem, in which impaction grafting and a cemented stem in the diaphysis was combined with an uncemented metaphyseal cone for revision TKAs with severely compromised bone. Methods. A metaphyseal cone was combined with diaphyseal impaction grafting and cemented stems in a novel fashion for 35 revision TKAs. Mean age at revision TKA was 70 years, with 63% being male. Patients had a mean of 4 prior knee arthroplasty procedures. Indications for the revision with this construct were aseptic loosening (80%) and two-stage re-implantation for periprosthetic infection (PJI; 20%). Mean follow-up was 3 years. Results. Survivorship free from revision of the cone/impaction grafting construct due to aseptic loosening was 100% at 5 years. Survivorships free from any revision of the cone/impaction grafting construct and free from any reoperation were 92% and 73% at 5 years, respectively. Six knees (17%) required a reoperation (4 for infection/wound issues and 2 for periprosthetic fractures). Radiographically, 97% of cones were ingrown (1 loose cone in setting of PJI). In all but one case, impacted diaphyseal bone graft appeared to have incorporated radiographically. Conclusions. When presented with a sclerotic diaphysis and substantial metaphyseal bone loss, this innovative technique combining diaphyseal impaction grafting with a metaphyseal cone provided near universal success in regards to implant fixation. Moreover, radiographs revealed incorporation of the bone graft, and ingrowth of the cones. While long-term follow-up is required, this novel technique provides an excellent option in the most difficult of revision TKAs. For figures, tables, or references, please contact authors directly

The most common classification of periprosthetic femoral fractures is the Vancouver classification. The classification has been validated by multiple centers. Fractures are distinguished by location, stability of the femoral component, and bone quality. Although postoperative and intraoperative fractures are classified using the same three regions, the treatment algorithm is slightly different. Type A fractures involve the greater and lesser trochanter. Fractures around the stem or just distal to the stem are Type B and subcategorised depending on stem stability and bone quality. Type C fractures are well distal to the stem and are treated independent of the stem with standard fixation techniques. The majority of fractures are either B1 (stable stem) or B2 (unstable stem). The stem is retained and ORIF of the fracture performed for B1 fractures. B2 and B3 fractures require stem revision with primary stem fixation distal to the fracture. Intraoperative fractures use the same A, B, C regions but are subtyped 1–3 as cortical perforations, nondisplaced, and displaced unstable fractures, respectively. With the exception of A1 intraoperative fractures all other intraoperative fractures require surgical treatment. A recent publication utilizing a New York state registry highlighted the patient risk of mortality associated with periprosthetic hip fractures. One month, 6 month and 1 year mortality was 3.2%, 3.8% and 9.7%, respectively. The mortality risk was lower for periprosthetic fractures treated with ORIF at 1 and 6 months compared to fractures requiring revision total hip

The objective of this study was to evaluate the short term clinical and radiological results of a new short stem hip implant. In 29 consecutive patients suffering from osteoarthritis with 33 affected hip joints, the clinical and radiological results of 33 cementless hip arthroplasties using a cementless implanted short stem prosthesis type Aida and a cementless cup type Ecofit were evaluated prospectively between October 2009 and June 2015 in two hospitals. The median age of patients at time of surgery was 55 years (range, 30–71 years), 23 male and 10 female patients were included in the study. The median clinical follow up was 24 months (range, 1.5–51 months), and the median radiological follow up was 12 months (range, 1–51 months). Two patients were lost to follow up and two patients had only one immediate postoperative x- ray. The Harris Hip Score improved from a median preoperative value of 53 to a median postoperative value of 93 at follow up. Radiological analysis showed that 19 stems (58%) showed stable bony ingrowth, five cases (15%) showed stable fibrous ingrowth. Four cases need further follow up for proper evaluation of stem fixation. The short term survival of this new short stem is very promising, and achieving the goals of standard hip arthroplasty

Introduction. The Vancouver Classification System presents a systematic approach to classification of periprosthetic fractures of the proximal femur (PFPFs) that has been validated in previous studies. However, with the introduction of tapered fluted stems and cable plates since the introduction of the Vancouver System, the connection between fracture class and the preferred method of treatment is often unclear. The present study was undertaken to identify fracture patterns surrounding contemporary femoral stems and the relationship between the current method of treatment and the Vancouver Class of the periprosthetic fracture. Methods. Three experienced joint surgeons collected plain radiographs (AP and lateral) and CT/MR scans (n=40) from 72 cases of Vancouver A or B periprosthetic fractures performed over the period 2016–2018. We identified the mode of primary stem fixation and the Vancouver grade of the fracture (A, B1, B2 or B3). Two independent investigators examined all imaging studies and the intraoperative records and recorded: (i) and the location and distribution of the fracture surfaces, and (ii) the presence of incomplete cortical fractures that had initiated within the femoral cortex without completing propagation and (iii) the method of operative treatment. These data were analyzed to examine the incidence of fractures within more than one femoral zone and differences in the fracture patterns corresponding to each Vancouver class. Results. One fifth (21%) of fractures were Type A with the remainder consisting predominantly of Type B2 (39%), with approximately equal proportions of Type B1 (22%) and B3 (18%) fractures. In almost half of Type B2 fractures (a loose femoral stem and a fracture adjacent to the prosthesis), fractures were also present within the metaphysis (ie. Type A+B). In the presence of a cementless femoral stem, fractures often occurred adjacent to the uncoated surface of the stem distal to the proximal ingrowth surface. Type B2 and B3 femurs had similar fracture patterns and degrees of comminution, though their method of treatment differed significantly. Incomplete fractures were identified in every Vancouver class (entire sample: 22%), especially in association with loose stems in poor quality bone (Type B3; 38% of cases). Conclusions. Approximately two-thirds of periprosthetic femoral fractures involve a loose femoral component (ie Types B2 and B3), though bone quality impacts operative treatment. In cementless stems, Vancouver Type B fractures often occur in the unbonded diaphysis between the distal edge of the ingrowth surface and immediately below the stem tip. Incomplete fractures are present in a surprising proportion of cases, suggesting that careful examination of imaging studies is needed to prevent fracture propagation due to inadequate fixation. CT scans are a useful adjunct to supplement plain radiographs. For any tables or figures, please contact the authors directly

INTRODUCTION. The Woodpecker pneumatic broaching system facilitates femoral preparation to achieve optimal primary fixation of the stem in direct anterior hip replacement using a standard operating table. The high-frequency axial impulses of the device reduce excess bone tension, intraoperative femoral fractures and overall operating time. The Woodpecker device provides uniformity and enhanced control while broaching, optimizing cortical contact between the femur and implant and thereby maximizing prosthetic axial stability and longevity. This study aims to describe a single surgeon's experience using the Woodpecker pneumatic broaching system in 649 cases of direct anterior approach (DAA) total hip arthroplasties to determine the device's safety and efficacy. METHODOLOGY. All consecutive patients undergoing elective anterior bikini total hip arthroplasties (THA) performed by a single surgeon between July 2013 and June 2018 were included. Patients undergoing a THA with the use of the Woodpecker device through a different surgical approach, revision THA or arthroplasties for a fractured neck of femur were excluded (n=219). The pneumatic device was used for broaching the femoral canal in all cases. Pre-operative and post-operative Harris Hip Scores (HHS) and post-operative radiographs were analyzed to identify femoral fractures and femoral component positioning at 6 weeks, 6 months and 12 months post-operative. Any intra-operative or post-operative surgical complications and component survivorship until most recent follow up were recorded in the clinical notes. RESULTS. A total of 649 patients (L THA=317, R THA=328 and bilateral=2) with a mean age of 69 (range 46–91yrs) and mean BMI of 28.3 (range = 18.4–44.0) underwent a DAA THA using a Woodpecker device were included in the study. Of these patients, 521 (80%) underwent uncemented and 128 (20%) underwent cemented femoral components. The time taken to broach the femur using Woodpecker broaching this system averaged 2.8 minutes (1.4 to 7.5 minutes) in both cemented and uncemented cases. In 91% of cases the templated broach size was achieved with the remaining 9% within +/− 1 size of the planned template. Radiographic analysis revealed 67.3% of the stems placed in 0–1.82 degrees of varus and 32.7% placed in 0–1.4 degrees of valgus. Average HHS were 24.4 pre-operatively, with drastic improvements shown at 6 weeks (80.95), 6 months (91.91) and 12 months (94.18) after surgery. Intraoperative femoral fractures occurred in three patients (0.4%) during trial reduction, a further three patients had periprosthetic post-operative fractures (0.4%) from falls, two patients had stem subsidence (0.3%) and a further two patients had wound infections (0.3%). At the most recent follow up, the survivorship of the acetabular component was 99.7% and the femoral component was 99.1%, with mean follow up of 2.9 years (0.5 to 5 years). No intraoperative or post-operative complications could be directly attributed to the Woodpecker broaching system. CONCLUSION. The pneumatic Woodpecker device is a safe and effective alternative tool in minimally invasive direct anterior hip replacement surgery for femoral broaching performed on a standard operating table. The skill and experience of the surgeon must be taken into consideration when utilizing new surgical devices

Aim. The objective of this study was to evaluate the intermediate term clinical and radiological results of a new short stem hip implant. Methods. In 20 consecutive patients suffering from osteoarthritis with 25 affected hip joints (five cases were bilateral), the clinical and radiological results of 25 hip arthroplasties performed in one hospital between October 2009 and May 2014 through a minimally invasive anterolateral approach using a cementless short stem prosthesis type Aida and a cementless cup type Ecofit with a ceramic on ceramic pairing were evaluated prospectively. The median age of patients at time of surgery was 60 years (range, 42–71 years), 15 male (4 were bilateral) and 5 female patients (one was bilateral) were included in the study. The median clinical follow up was 30 months (range, 2–88 months), and the median radiological follow up was 30 months (range, 2–88 months). Results. Harris Hip Score improved from a median preoperative value of 53 to a median postoperative value of 96 (range, 73–100) at follow up. 22 hips (88%) showed an excellent postoperative Harris Hip Score, 2 hips (8%) a good postoperative Harris Hip Score, and one hip (4%) a fair postoperative Harris Hip Score. Only two patients complained of postoperative thigh pain. Regarding patient satisfaction, 15 patients (60%) were very satisfied, 10 patients (40%) were satisfied. None was unsatisfied. Radiological analysis showed that 19 stems (76%) were with stable bony ingrowth, two cases (8%) showed stable fibrous ingrowth. Four cases need further follow up for proper evaluation of stem fixation.(See Figures 1,2,3). Conclusion. The intermediate term survival of this new short stem is very promising, and achieving the goals of a standard hip arthroplasty. For any figures or tables, please contact the authors directly

Background. Antibiotic loaded bone cement (ALBC) is commonly used in cemented total hip arthroplasty (THA) in an attempt to reduce the risk of prosthetic joint infection (PJI). However, its role versus plain cement remains controversial due to the potential risk of developing resistant organisms and potential excess costs incurred from its usage. We investigated the relationship of ALBC and plain cement in affecting outcome of revision surgery after primary THA. Methodology. We conducted a retrospective study of data collected from National Joint Registry for England and Wales, Northern Ireland and the Isle of Man between 1. st. September 2005 until 31. st. August 2017. A logistic regression analysis model was used to investigate the association between ALBC versus plain cement and the odds ratio (OR) for revision, adjusting for age, ASA grade, bearing surfaces, head size and cup and stem fixation. Indications for revision recorded in NJR were considered in separate models. Results. We identified 418,925 THAs where bone cements were used (22,037 plain cement; 396,888 ALBC). After adjusting for confounding factors, the risk of revision for infection was lower with ALBC (OR 0.77, 95% CI 0.62–0.95). There was also lower risk of revision for aseptic loosening of stem (OR 0.53, 95% CI 0.39–0.72), aseptic loosening of socket (OR 0.46, 95% CI 0.37– 0.58). When breaking down hips into fully cemented or hybrid fixation, the protective effect of ALBC against infection was only apparent in fully cemented (OR 0.65, 95% CI 0.48–0.87) when compared against hybrid fixation (OR 0.90, 95% CI 0.66–1.23). Discussion. Within the limits of registry analysis, this study has demonstrated an association between the use of ALBC and lower rates of revision for infection and aseptic loosening. Conclusion. This finding supports the current use of ABLC in cemented THAs

Background:. For hip prostheses, short stems allow easy insertion and reduce thigh pain risk, and are therefore suitable for Minimally Invasive Surgery. However, clinical outcome depends on sufficient initial fixation in the proximal femoral component. Revelation stems are designed to increase medullary cavity occupancy in the proximal femoral component and allow physiological load transmission within this component. Theoretically, on initial fixation of the proximal part of the stem, fixation remains unaffected by cutting the distal part of the stem. Recently, the Revelation micro MAX stem has become available. In this system, only the distal part of the stem is removed. To prepare for the introduction of this stem, we evaluated its rotational stability by installing it in the femurs of formalin-fixed cadavers. We then evaluated the time course of changes in bone density at the stem circumference and stem position by CT in the first eight patients undergoing hip arthroplasty. Subjects and Methods:. Micro MAX stems were inserted into the left femurs of one male and six female cadavers (76 to 95 years of age). A commonly used torque meter was mounted on the stem, and stem fixation was evaluated by the application of clockwise torque of 6 to 12 N-m. Further, in patients, three men and five women (age range 38–83 years, mean 67 years; two cases of femoral head necrosis, two of femoral neck fracture, and four of osteoarthritis of the hip) who underwent surgery with the micro MAX stem from July 2012 to April 2013 were evaluated at 3 weeks, and 3 and 6 months after surgery for stem insertion angle and stem subsidence by CT, and for bone density around the stem by the DEXE method. Results:. Rotational stability of the micro MAX stem in cadaveric femurs was similar to that of the conventionally used Revelation stem. In CT examination after surgery, the micro MAX stem tended to be inserted in a slightly varus position. No evidence of stem subsidence was observed in eight patients, but progression of the varus was seen in one. Bone density in the stem circumference was maintained. Discussion:. Although short stems have a number of advantages, problems with the first fixation might result in loosening. Allowing for the small number of patients and limited range of clinical conditions, our findings suggest that the rotational stability of the micro MAX stem is similar to that of the conventional stem. Postoperative CT measurement indicated that the micro MAX stem tended to be inserted in the varus position, particularly in patients with a large medullary cavity. The micro MAX stem was stable, and no decrease in bone density was seen. As with other short stems, however, care is required to avoid insertion in the varus position in patients with a large medullary cavity. Conclusion:. This investigation identified no problems in initial fixation with the micro MAX stem. Clinical outcomes with this system should be favorable

In contrast to the acetabular cup where the close to spherical shape of the implant allows a precise alignment and positioning, the femoral stem implant positioning has always been a compromise between anteversion, angulation and length of the prosthetic femoral neck and the congruence of the implant shaft with the inner anatomical shape of the proximal femur. Balancing these reduces the risks of dislocation and eccentric wear of the acetabular implant and of unfeasible loading of the femoral implant with loosening. Nevertheless neither the anchorage of the stem nor the alignment of the neck can ever be ideal as it would too much jeopardize the other aspect even if cement is used for stem fixation. Customary stem navigation only guides this compromise more precisely than eye balling. With the introduction of modular necks it has become possible to infringe this restrictive fix relation and after fully fitting stem fixation the neck alignment and length is optimized separately. With regard to computer assisted navigation the guidance takes into consideration the definitive stem position after best anatomical fixation. A sound navigation of cemented stems becomes also possible and brings up the opportunity to choose cementing or uncemented fixation based on whether the bone quality needs reinforcement by cement to get closer to the implant e-module or the bone promises to strengthen on its own on the same purpose

Longevity of the implants is the most respected factor in THA. Except from this fact, complications like dislocation, wear and osteolysis are reported in literature most frequently. But there is an underestimation in the orthopedic community in the importance of joint function, which is directly related to accurate restoration of joint geometry. This might be due to a lack of functional parameters for the measurement and availability of adequate implants for accurate restoration of joint geometry. From our point of view the two problems: stable stem fixation and joint geometry have to be addressed separately: Safe stem fixation on the one hand, adequate joint geometry on the other hand. With the use of standard implants compromises have to be made on either side. To avoid this dilemma, we propose alternative systems: A modular system with interchangeable necks as a standard implant for better fit and adequate joint geometry or a custom implant. In the presentation we address the interference of stem fit and joint geometry and discuss problems and advantages of modularity and custom implants

We undertook a review of the literature relating to the two basic stem designs in use in cemented hip replacement, namely loaded tapers or force-closed femoral stems, and the composite beam or shape-closed designs. The associated stem fixation theory as understood from in vitro studies and finite element modelling were examined with reference to the survivorship results for each of the concepts of fixation. It is clear that both design principles are capable of producing successful long-term results, providing that their specific requirements of stem metallurgy, shape and surface finish, preparation of the bone and handling of the cement are observed

Introduction: In the past, surgeons have found impaction bone grafting technically difficult leading to its limited use. This paper reviews the long term results and developments in instrumentation and techniques aimed at simplifying femoral impaction grafting at revision hip replacement. The expanded indications for this procedure are reviewed and recent results of stem fixation using radiostereometric analysis (RSA) are reported. Methods: The impaction bone grafting procedure, using a cemented collarless polished double taper stem, has been used in 66 hips (median patient age 63yrs) since 1993. The technique has undergone numerous developments. Modular tamps have been used in the last 29 hips and in the last seven hips, a pneumatic mechanical vibration device has been used in place of manual impaction. Stem subsidence at both the prosthesis-cement and cement-graft/bone interfaces was measured, more recently using radiostereometric analysis. Results: There was a high early incidence of failure in the initial cases but there have been no further revisions for mechanical failure at up to 15 years. Technique developments have resulted in dramatic improvements in stem fixation achieved. In the modular tamp cases, the mean stem subsidence at the cement-bone interface at 12 months was 0.07mm (0 to 0.7mm) at 12 months. The stem subsidence in the hips where the mechanical vibration device was used was 0.05mm (0 to 0.06mm). Femoral impaction grafting offers special advantages in younger patients include standard femoral stem revision and at the second stage of two stage revision for infection. Discussion and Conclusion: A stable cement-bone interface is achieved using advanced techniques of femoral impaction grafting that includes the use of modular impaction instruments. Early results of mechanical vibration impaction are encouraging. Femoral impaction grafting restores bone and new techniques simplify the femoral revision procedure

Introduction. Proper initial fixation of the stem in the femoral canal is important to achieve successful long-term clinical results in total hip arthroplasty (THA) and bipolar hemiarthroplasty (BHA). However, this factor fully relies on surgeon's experience and skill during the hammering process. The goal of this study is to evaluate the frequency of the stem hammering sound which enables the achievement of proper stem fixation and avoiding femoral bone fracture. Materials and methods. 57 patients who received BHA as a result of femoral neck fracture were evaluated. Intraoperative images of stem hammering were recorded using a digital video camera (Everio GZ-MG275, Victor, Japan). The frequency of the hammering sound was analyzed using a digital audio editor, GoldWave (GoldWave Inc.) (Figure 1). The frequency change during hammering was categorized into two groups, convergent and non-convergent, according to the frequency change pattern (Figure 2). The definition of “convergent group” is as follows: in the last five hammering sounds to finish the stem insertion, 1) Three consecutive hammering frequency shape and distribution 2) Formant peak frequency within the range of 3,000 Hz. Two types of cementless stems, SYNERGY SELECT II (tapered) and ECHELON TITANIUM (cylindrical, both from Smith & Nephew, Inc.) were used. Stem hammering was conducted using the same stem inserter. Canal Flare Index (CFI), Cortical Index (CI), Singh Index (SI), canal filling ratio, and the total number of stem-cortex contact zones were evaluated on x-ray images. The Mann-Whitney U-test was used for statistical analysis. Results. The number of contact zones was significantly different between convergent and non-convergent groups in both SYNERGY and ECHELON stems. However, no significant difference was found in CFI, CI, SI, and canal filling ratio. With the SYNERGY stem 24 cases showed convergence in hammering frequency and non-convergence in 16 cases. The mean total contact zones were 6.08±1.18 (convergent group) and 4.44±1.71 (non-convergent group). In the ECHELON group 9 cases showed convergence in hammering frequency and non-convergence in 8 cases. The total contact zones were 6.78±1.09 (convergent group) and 4.88±1.55 (non-convergent group) (Table 1). Discussion. Regardless of femoral geometry and stem design, hammering sound frequency was convergent when the stem-bone contact area increased. Change in the hammering sound frequency can provide reliable information during the stem insertion in terms of stem-bone contact to prevent bone fracture

INTRODUCTION. Recently, short shaped stem becomes popular in total hip arthroplasty (THA). Advantages of the short stem are preserving femoral bone stock, thought to be less thigh pain, suitable for minimally invasive THA. However, bony reaction around the short stem has not been well known. The purpose of this study was to compare the two years difference of radiographic change around the standard tapered round stem with the shorter tapered round stem. MATERIALS AND METHODS. Evaluation was performed in 96 patients (100 joints) who underwent primary THA. Standard tapered round stem (Bicontact D stem) was used in 44 patients from January 2011 to May 2013. Shorter stem (Bicontact E stem) was used in 56 patients from May 2015 to March 2016. The proximal shapes of these two stems are almost the same curvature. The mean age at surgery was 64 years. The mean BMI at surgery was 24.0 kg/m. 2. Eighty-six patients had osteoarthrosis and 10 patients had osteonecrosis. Evaluation was performed 2 years after surgery with standard AP radiographs. The OrthoPilot imageless navigation system was used during surgery. Evaluation of the stem fixation, stress shielding, and cortical hypertrophy were carried out. RESULTS. There were no differences of patient characteristics between the standard D stem group and the shorter E stem group. All 100 stems showed bony stable fixation two years after surgery. No subsidence was observed in both groups. No clear zone was observed around the stems in both groups. Cortical hypertrophy was observed 19 patients (43.2%) with the standard D stem group and 13 patients (23.2%) with the shorter E stem group. The standard D stem group showed higher incidence of cortical hypertrophy. Stress shielding was observed 35 patients (80%) with the standard D stem group and 42 patients (75%) with the shorter E stem group. The number of grade 1 and grade 2 stress shielding cases were 13 and 22 with the standard D stem group and 10 and 32 with the shorter E stem group, respectively. There were no grade 3 stress shielding case in both groups. Regarding the incidence of stress shielding, there was no difference between the two groups. DISCUSSION. This study demonstrated that the shorter stem showed less incidence of cortical hypertrophy compared to the standard stem. With radiographic evaluation, both standard and shorter stem showed good fixation. The meaning of cortical hypertrophy, whether it is a good reaction for the femur or not, has not been clarified yet. Less bony reaction around the shorter stem may suggest the potential for better clinical performance of the shorter stem compare to the standard stem