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Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 22 - 22
1 Feb 2020
Van De Kleut M Athwal G Yuan X Teeter M
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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


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 84 - 84
1 Feb 2020
Dennis D Pierrepont J Madurawe C Friedmann J Bare J McMahon S Shimmin A
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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


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_9 | Pages 48 - 48
1 May 2016
Mochida Y Ishii K Miyamae Y Matsumoto R Taki N Mitsugi N Saito T
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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.

Materials and Methods

In surgery, the femoral neck was cut and prepared without using a box chisel, reamer or broaches, instead, a series of trial stems were used with the method of impaction technique. After impaction of cancellous bone with the final size of the trial stem, the stem is fixed by bone cement without taking any cement mantle. Full weight bearing was allowed for all patients from the next day of the surgery. We investigated short-term clinical and radiographic results and the incidence of complication that was related to this technique. Post-operative radiological results with the minimum follow-up of 12 months after surgery were analyzed in 31 joints (25 cases) with this technique. The mean age at the time of surgery was 66.3 years (46∼82). The mean duration after surgery was 62 months (14∼108).


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XLI | Pages 107 - 107
1 Sep 2012
Boldt J
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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.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 46 - 46
1 Dec 2022
Sheridan G Garbuz D Masri B
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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


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_8 | Pages 65 - 65
1 May 2019
Ries M
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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


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_8 | Pages 79 - 79
1 May 2019
Engh C
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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


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_5 | Pages 31 - 31
1 Apr 2019
Elkabbani M El-Sayed MA Tarabichi S Schulte M
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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


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 142 - 142
1 Feb 2020
Nizam I Batra A Gogos S
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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


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 533 - 533
1 Dec 2013
Shibata Y Iguchi H Murakami S Mitsui H
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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


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_5 | Pages 40 - 40
1 Apr 2019
Elkabbani M El-Sayed MA Tarabichi S Malkawi AS Schulte M
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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


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 297 - 297
1 Mar 2013
Oyama J Furuichi I Murata M Endo M
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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


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 133 - 133
1 Apr 2019
Taki N Mitsugi N Mochida Y Yukizawa Y Sasaki Y Takagawa S
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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


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_10 | Pages 117 - 117
1 Jun 2018
Whiteside L
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Stems are a crucial part of implant stabilization in revision total knee arthroplasty. In most cases the metaphyseal bone is deficient, and stabilization in the diaphyseal cortical bone is necessary to keep the implant tightly fixed to bone and to prevent tilt and micromotion. While sleeves and cones can be effective in revision total joint arthroplasty, they are technically difficult and may lead to major bone loss in cases of loosening or infection, especially if the stem is cemented past the cone. A much more conservative method is to ream the diaphysis to the least depth possible to achieve tight circumferential fixation, and to apply porous augments to the undersurface of the tibial tray or inner surface of the femoral component to allow them to bottom out against the bone surface and apply compressive load. If a robust, strong taper, stem and component combination is used, rim contact on only one side is necessary to achieve rigid permanent fixation. Porous and non-porous stems are available. The non-porous stems should have a spline surface that engages the diaphyseal bone and achieves rigid initial fixation but does not provide long-term axillary support. In that way the porous rim-engaging surface can bear compressive load and finally unload the stem and taper junction. Correctly designed stems do not stress relieve unless they are porous-coated. In situations where metaphyseal bone is not available, porous-coated stems that link to hinge prostheses are a very important part of the armamentarium in complex revision arthroplasty. Use of stems requires experience and special technique. Slight underreaming and initial scratch fit are necessary techniques. This does not result in tight fixation every time because split of the cortex does occasionally occur. In most cases these splits do not need to be repaired, but when there is a question, an intra-operative x ray should be taken and the surgeon should be prepared to repair the fracture. Stems are an essential part of revision total knee arthroplasty. A tightly fit stem in the diaphysis is necessary for fixation when metaphyseal bone is deficient. No amount of cement pressed into the deficient metaphyseal bone will substitute for rigid stem fixation


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_10 | Pages 16 - 16
1 Jun 2018
Berry D
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The Failed Femoral Neck Fracture. For the young patient: Attempt to preserve patient's own femoral head. Clinical results reasonably good even if there are patches of avascular necrosis. Preferred methods of salvage: valgus-producing intertrochanteric femoral osteotomy: puts the nonunion under compression. Other treatment option: Meyer's vascularised pedicle graft. For the older patient: Most reliable treatment is prosthetic replacement. Decision to use hemiarthroplasty (such as bipolar) or THA based on quality of articular cartilage, perceived risk of instability problem. In most patients THA provides higher likelihood of excellent pain relief. Specific technical issues: (1) hardware removal: usually remove after hip has first been dislocated (to reduce risk of femur fracture); (2) Hip stability: consider methods to reduce dislocation risk: larger diameter heads/dual mobility/anteriorly-based approaches; (3) Acetabular bone quality: poor because it is not sclerotic from previous arthritis; caution when impacting a pressfit cup; low threshold to augment fixation with screws; don't overdo reaming; just expose the bleeding subchondral bone. A reasonable alternative is a cemented cup. The Failed Intertrochanteric Hip Fracture. For the young patient: Attempt to salvage hip joint with nonunion takedown, autogenous bone grafting and internal fixation. For the older patient: Decision to preserve patient's own hip with internal fixation versus salvage with hip arthroplasty should be individualised based on patient circumstances, fracture pattern, bone quality. THA is an effective salvage procedure for this problem in older patients. If prosthetic replacement is chosen special considerations include:. THA vs. hemiarthroplasty: hemiarthroplasty better stability; THA more reliable pain relief. Removal of hardware: be prepared to remove broken screws in intramedullary canal. Management of bone loss: bone loss to level of lesser trochanter common. Often requires a calcar replacement implant. Proximal calcar build-up size dictated by bone loss. Length of stem: desirable to bypass screw holes from previous fixation, if possible. Stem fixation: cemented or uncemented fixation depending on surgeon preference, bone quality. If uncemented, consider diaphyseal fixation. Greater trochanter: often a separate piece, be prepared to fix with wires or cable grip. Residual trochanteric healing, hardware problems not rare after THA


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_22 | Pages 120 - 120
1 Dec 2016
Ranawat C
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Mastering the Art of Cemented Femoral Stem Fixation: Fixation of cemented femoral stems is reproducible and provides excellent early recovery of hip function in patients 60 to 80 years old. The durability of fixation has been evaluated up to 20 years with 90% survivorship. The mode of failure of fixation of cemented total hip arthroplasty is multi-factorial; however, good cementing techniques and reduction of polyethylene wear have been shown to reduce its incidence. The importance of surface roughness for durability of fixation is controversial. This presentation will describe my personal experience with the cemented femoral stem over 30 years with 3 designs and surface roughness (RA) ranging from 30 to 150 microinches. Cemented Primary Acetabulum: I am going to present a technique of cementing an all-poly socket. We have looked at our all-poly socket from 1992 to 1998 and the total number of hips are over 1,000, with a follow-up of 2 to 8 years. We have not revised a single socket for fixation failure


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_10 | Pages 20 - 20
1 Jun 2018
Springer B
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Periprosthetic fractures around the femur during and after total hip arthroplasty (THA) remain a common mode of failure. It is important therefore to recognise those factors that place patients at increased risk for development of this complication. Prevention of this complication, always trumps treatment. Risk factors can be stratified into: 1. Patient related factors; 2. Host bone and anatomical considerations; 3. Procedural related factors; and 4. Implant related factors. Patient Factors. There are several patient related factors that place patients at risk for development of a periprosthetic fracture during and after total hip arthroplasty. Metabolic bone disease, particularly osteoporosis increases the risk of periprosthetic fracture. In addition, patients that smoke, have long term steroid use or disuse, osteopenia due to inactivity should be identified. A metabolic bone work up and evaluation of bone mineralization with a bone densitometry test can be helpful in identifying and implementing treatment prior to THA. Pre-operative Host Bone and Anatomic Considerations. In addition to metabolic bone disease the “shape of the bone” should be taken into consideration as well. Dorr has described three different types of bone morphology (Dorr A, B, C), each with unique characteristics of size and shape. It is important to recognise that not one single cementless implant may fit all bone types. The importance of templating a THA prior to surgery cannot be overstated. Stem morphology must be appropriately matched to patient anatomy. Today, several types of cementless stem designs exist with differing shape and areas of fixation. It is important to understand via pre-operative templating which stem works best in what situation. Procedural Related Factors. There has been a resurgence in interest in the varying surgical approaches to THA. While the validity and benefits of each surgical approach remains a point of debate, each approach carries with it its own set of risks. Several studies have demonstrated increased risk of periprosthetic fractures during THA with the use of the direct anterior approach. Risk factors for increased risk of periprosthetic fracture may include obesity, bone quality and stem design. Implant Related Factors. As mentioned there are several varying cementless implant shapes and sizes that can be utilised. There is no question that cementless fixation remains the most common mode of fixation in THA. However, one must not forget the role of cemented fixation in THA. Published results on long term fixation with cemented stems are comparable if not exceeding those of press fit fixation. In addition, the literature is clear that cemented fixation in the elderly hip fracture patient population is associated with a lower risk of periprosthetic fracture and lower risk of revision. The indication and principles of cemented stem fixation in THA should not be forgotten


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_7 | Pages 23 - 23
1 Apr 2017
Stulberg S
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Cementless femoral stems of many designs now provide dependable long-term fixation and excellent, near normal function in patients of all ages, sexes and level of activity. However, a number of issues related to cementless stem fixation could be further improved: Optimization of load transfer to proximal femur to minimise fracture risk and maximise bone preservation; Elimination of proximal-distal mismatch concerns, including bowed femurs; Facilitation of femoral stem insertion, especially for Anterior and MIS exposures; Facilitation of revision with implants capable of providing durable fixation for active patients. The potential benefits of short stem femoral THA implants include: Ease of insertion; Reproducibility of insertion; Avoidance of issues related to proximal-distal anatomic mismatch or variations in proximal femoral diaphyseal anatomy (e.g. femoral bowing); Facilitation of MIS surgical approaches, especially anterior exposures; Optimization of proximal femoral load transfer with consequent maximization of proximal bone preservation. The purpose of this presentation is to describe the design rationale and characteristics of short (< 120 mm) uncemented primary THA femoral stems and to evaluate the clinical and radiographic results of short stems. Outcome results extending beyond 10 years support the proposition that short stems of appropriate design provide dependable long-term fixation and equivalent clinical results to those currently achievable with cementless stems of conventional length in patients of all ages, sexes and level of activity


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_22 | Pages 45 - 45
1 Dec 2017
Glehr M Klim S Sadoghi P Bernhardt G Leithner A Radl R Amerstorfer F
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Aim. One of the most challenging problems in total knee arthroplasty (TKA) is periprosthetic infection. A major problem that arises in septic revision TKA (RTKA) are extended bone defects. In case of extended bone defects revision prostheses with metaphyseal sleeves are used. Only a few studies have been published on the use of metaphyseal sleeves in RTKA - none were septic exclusive. The aim of our study was to determine the implant survival, achieved osseointegration as well as the radiological mid-term outcomes of metaphyseal sleeve fixation in septic two-stage knee revision surgery. Method. Clinical and radiological follow-up examinations were performed in 49 patients (25 male and 24 female). All patients were treated with a two-stage procedure, using a temporary non-articulating bone cement spacer. The spacer was explanted after a median of 12 weeks (SD 5, min. 1 – max. 31) and reimplantation was performed, using metaphyseal sleeves in combination with stem fixation. Bone defects were classified on preoperative radiographs using the Anderson Orthopaedic Research Institute (AORI) classification. During follow-up postoperative range of motion (ROM) was measured and radiographs were performed to analyse: (i) osseointegration (radiolucent lines and spot welds), (ii) leg alignment, (iii) patella tilt and shift. Results. All types of bone defects were found on the tibial (4× type 1, 7× type 2a, 26× type 2b, 9× type 3) as well as on the femoral side (1× type 1, 4× type 2a, 20× type 2b, 6× type 3). Mean follow-up time was 4.7 years (minimum 1 year). In total 12 knees (24.5%) had to be re-revised, all due to re-infection. We did not encounter any case of aseptic loosening. In 3 patients (6.8%) we detected an insufficient osseointegration, but no patient had to be re-revised due to only minimal or to the absence of symptoms and no clinical signs of loosening. The ROM (mean 93°, SD 20.6, min. 25° max. 125°) has shown very satisfying results at the time of follow-up. Malalignment was detected in 4 patients (10.3%), a patella tilt in 7 (19.4%) and a patella shift in 14 (48.3%). Conclusions. Metaphyseal Sleeves have shown very promising mid-term results regarding osseointegration and aseptic implant survival in RTKA with compromised metaphyseal bone stock. Our results indicate that they are a reliable fixation option in septic RTKA patients


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_7 | Pages 16 - 16
1 Apr 2017
Hozack W
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Despite the best of technique, when faced with a sub-capital or per-trochanteric fracture, inevitably there are failures of proximal fixation. These situations provide unique challenges for the reconstructive surgeon. While there are specific issues related to either sub-capital or per-trochanteric fractures, there also are many commonalities. The causes of failure are nonunion, malunion, failure of fixation or avascular necrosis. In all cases, it is imperative to rule out infection. Since the surgery is now elective, the patient's medical status must be optimised prior to the intervention. Basic surgical principles apply to both fracture types. Use the old incision (if possible) and choose an approach that can be extensile. Of course, the old hardware needs to be removed – this task can be quite frustrating, so good preparation and patience is imperative. Retrieve old operative notes to identify the type of hardware so that any special tools needed are available. Hardware can be intra-osseous in location and excavation of the hardware may require bone osteotomy. These patients are at higher risk of post-operative dislocation, so absolute hip stability must be achieved and confirmed in the OR. Bigger heads and dual mobility options improve stability provided that the components are properly positioned and offset and leg length are restored. Subcapital fractures provide certain specific issues related to stem choice. While, my bias is towards THA because of better chance of complete pain relief, especially in community ambulators, certainly bipolar arthroplasties can be a satisfactory solution. Stem fixation can be either cemented or cementless. For per-trochanteric fractures in younger patients, repeat osteosynthesis should be considered if the femoral head is viable. Bone deformity – trochanteric overhang, shaft offset – may necessitate an osteotomy as part of the reconstruction. While proximal fixation primary type stems are often possible, distal fixation revision stems may be required. Any bone defects related to screw holes should be bypassed by the femoral component