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Bone & Joint Research
Vol. 13, Issue 10 | Pages 611 - 621
24 Oct 2024
Wan Q Han Q Liu Y Chen H Zhang A Zhao X Wang J

Aims. This study aimed to investigate the optimal sagittal positioning of the uncemented femoral component in total knee arthroplasty to minimize the risk of aseptic loosening and periprosthetic fracture. Methods. Ten different sagittal placements of the femoral component, ranging from -5 mm (causing anterior notch) to +4 mm (causing anterior gap), were analyzed using finite element analysis. Both gait and squat loading conditions were simulated, and Von Mises stress and interface micromotion were evaluated to assess fracture and loosening risk. Results. During gait, varied sagittal positioning did not lead to excessive Von Mises stress or micromotion. However, under squat conditions, posterior positioning (-4 and -5 mm) resulted in stress exceeding 150 MPa at the femoral notch, indicating potential fracture risk. Conversely, +1 mm and 0 mm sagittal positions demonstrated minimal interface micromotion. Conclusion. Slightly anterior sagittal positioning (+1 mm) or neutral positioning (0 mm) effectively reduced stress concentration at the femoral notch and minimized interface micromotion. Thus, these positions are deemed suitable to decrease the risk of aseptic loosening and periprosthetic femoral fracture


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_15 | Pages 77 - 77
1 Aug 2017
Abdel M
Full Access

Over the past several decades, cementless femoral fixation for primary total hip arthroplasties (THAs) has become more common in North America. It is estimated that nearly 90% of all primary THAs completed in the United States are cementless. In the Australian National Joint Replacement Registry, the use of cementless fixation has increased from 51.3% in 2003 to 63.3% in 2015. During the same time period, cemented fixation declined from 13.9% to 3.7%, but hybrid fixation was relatively stable at about 33%. This is likely related to the fact that multiple institutional and national registries have shown a higher rate of intra-operative periprosthetic femoral fractures with the use of cementless femoral components in certain patient populations. Those risk factors include patients greater than 65 years of age, female patients, and those with significant osteoporosis and Dorr C canals. However, it is important to note that not all cementless femoral components are similar. In fact, there is great variation in not only the geometry of cementless femoral components, but also in the type and extent of the biologic ingrowth surfaces. Each design has unique advantages and disadvantages. While some cementless femoral components are indicated for the general population, some are more specific and tailored to complex primary THAs (such as developmental dysplasia of the hip or post-traumatic arthritis with intra-operative concern for femoral version and thus hip stability) or revision procedures where distal fixation is needed (such as those with periprosthetic fractures or lack of proximal metaphyseal bony support). In 2000, Berry first described the evolution of cementless femoral components based upon distinct geometries that govern where fixation is obtained. This was modified in 2011 by Khanuja et al. to include six general types of cementless femoral components based upon shape. These include the following: Type 1: Single wedge; Type 2: Double edge with metaphyseal filling; Type 3: Tapered - A: Tapered round, B: Tapered spline/cone, C: Tapered rectangle; Type 4: Cylindrical fully coated; Type 5: Modular; Type 6: Anatomic. Type 1, 2, and 6 cementless femoral components obtain fixation in the metaphysis, whereas Type 3 stems obtain fixation in the metaphyseal-diaphyseal junction. Type 4 stems obtain fixation in the diaphysis. Type 5 stems can obtain fixation in either the metaphysis or the diaphysis. Within each type of stem, specific implant designs have had excellent long-term survivorship, while other specific implant designs have had higher than expected failure rates. Type 1 stems have the most published reports, and most contemporary reports indicate a stem survivorship greater than 95% at 15–20 years. Similar findings have been documented with specific implants from other types of stems when appropriate indications and surgical technique are utilised. Of note, one class of stems that has shown early failures due to adverse local tissue reactions (ALTR) is that of dual-modular necks. On the other hand, modular fluted tapered stems continue to produce excellent long-term data in complex primary THAs, as well as difficult revision THAs


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 82 - 82
19 Aug 2024
Courington R Ferreira R Shaath MK Green C Langford J Haidukewych G
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When treating periprosthetic femur fractures (PPFFs) around total hip arthroplasty (THA)], determining implant fixation status preoperatively is important, since this guides treatment regarding ORIF versus revision. The purpose of this study was to determine the accuracy of preoperative implant fixation status determination utilizing plain films and CT scans. Twenty-four patients who underwent surgery for Vancouver B type PPFF were included in the study. Two joint surgeons and two traumatologists reviewed plain films alone and made a judgment on fixation status. They then reviewed CT scans and fixation status was reassessed. Concordance and discordance were recorded. Interobserver reliability was assessed using Kendall's W and intraobserver reliability was assessed using Cohen's Kappa. Ultimately, the “correct” response was determined by intraoperative findings, as we routinely test the component intraoperatively. Fifteen implants were found to be well-fixed (63%) and 9 were loose. Plain radiographs alone predicted correct fixation status in 53% of cases. When adding the CT data, the correct prediction only improved to 55%. Interestingly, concordance between plain radiographs and CT was noted in 82%. In concordant cases, the fixation status was found to be correct in 55% of cases. Of the 18% of cases with discordance, plain films were correct in 43% of cases, and the CT was correct in 57%. Interobserver reliability demonstrated poor agreement on plain films and moderate agreement on CT. Intraobserver reliability demonstrated moderate agreement on both plain films and CT. The ability to determine fixation status for proximal PPFFs around uncemented femoral components remains challenging. The addition of routine CT scanning did not significantly improve accuracy. We recommend careful intraoperative testing of femoral component fixation with surgical dislocation if necessary, and the surgeon should be prepared to revise or fix the fracture based on those findings


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_12 | Pages 12 - 12
23 Jun 2023
Yee AHF Chan VWK Chiu K
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Uncemented femoral components have been used in total hip arthroplasties (THAs) for over three decades. Data on long-term performance of hydroxyapatite-coated femoral stems is however limited. This study reports the survivorship of a collarless, straight, hydroxyapatite-coated femoral stem (Omnifit HA, Osteonic) with a minimum of 20 years of follow-up. We reviewed the results of 165 THAs using Omnifit HA in 138 patients performed between August 1993 and December 1999. The mean age at surgery was 46 years (range 20 – 77 years). Avascular necrosis was the most common cause of THA, followed by ankylosing spondylitis and primary osteoarthritis. The mean follow-up was 22 years (range 20–31 years). At 20 and 25 years, 113 arthroplasties (91 patients) and 63 arthroplasties (55 patients) were available for follow-up respectively, while others had deceased or were lost to follow-up. Kaplan-Meier survivorship analysis was performed to evaluate the survival of the femoral component. Radiographs were reviewed at regular intervals, and implant stability was evaluated using Engh classification. Seven out of 165 stems were revised upon the latest follow-up; that included one case of aseptic loosening with revision done at 15 years, three peri-prosthetic fractures, two infections, and one recurrent dislocation. At 20 years, survivorship with revision of the femoral stem for any cause and aseptic loosening as the endpoint was 96.0% (95% CI, 92.6 – 99.5%) and 98.4% (95% CI, 96.2 – 100%) respectively. At 25 years, the corresponding survivorship rates were 94.5% (95% CI, 91.9 – 97.3%) and 98.1% (95% CI, 95.7 – 99.6%) respectively. Radiographic findings of stable bony fixation were seen in 86 stems (76.1%) and those of loosening in 4 stems (3.5%) at 20 years. All patients with radiographic signs of loosening were asymptomatic and did not require revision. The Omnifit HA femoral stem offered promising long-term survivorship into the third decade


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 129 - 129
4 Apr 2023
Adla P Iqbal A Sankar S Mehta S Raghavendra M
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Intraoperative fractures although rare are one of the complications known to occur while performing a total hip arthroplasty (THA). However, due to lower incidence rates there is currently a gap in this area of literature that systematically reviews this important issue of complications associated with THA. Method: We looked into Electronic databases including PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), the archives of meetings of orthopaedic associations and the bibliographies of included articles and asked experts to identify prospective studies, published in any language that evaluated intra-operative fractures occurring during total hip arthroplasty from the year 1950-2020. The screening, data extraction and quality assessment were carried out by two researchers and if there was any discrepancy, a third reviewer was involved. Fourteen studies were identified. The reported range of occurrence of fracture while performing hip replacement surgery was found to be 0.4-7.6%. Major risk factors identified were surgical approaches, Elderly age, less Metaphyseal-Diaphyseal Index score, change in resistance while insertion of the femur implants, inexperienced surgeons, uncemented femoral components, use of monoblock elliptical components, implantation of the acetabular components, patients with ankylosing spondylitis, female gender, uncemented stems in patients with abnormal proximal femoral anatomy and with cortices, different stem designs, heterogeneous fracture patterns and toothed design. Intraoperative fractures during THA were managed with cerclage wire, femoral revision, intramedullary nail and cerclage wires, use of internal fixation plates and screws for management of intra operative femur and acetabular fractures. The main reason for intraoperative fracture was found to be usage of cementless implants but planning and timely recognition of risk factors and evaluating them is important in management of intraoperative fractures. Adequate surgical site exposure is critical especially during dislocation of hip, reaming of acetabulum, impaction of implant and preparing the femoral canal for stem insertion. Eccentric and increased reaming of acetabulum to accommodate a larger cup is to be avoided, especially in females and elderly patients as the acetabulum is thinner. However, this area requires more research in order to obtain more evidence on effectiveness, safety and management of intraoperative fractures during THA


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XLI | Pages 109 - 109
1 Sep 2012
Sharr J
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Uncemented femoral components of hip arthroplasty are believed to have a higher risk of subsidence in older patient groups. This has not been conclusively related to a poorer outcome of the arthroplasty over time. Our aim is to measure prevalence of subsidence in uncemented femoral components in a population of patients over 75 years of age and correlate with clinical outcome measures. Patients over 75 years of age from Jan 2002 to Aug 2009 had uncemented THJR at the discretion of the senior surgeon (RF). Pre-operative Charnley Hip Classification and Harris Hip Scores were recorded, as were HHS at 6 weeks and 1 year post-operatively for all patients. Post-operative radiographs were retrospectively reviewed and presence of subsidence quantified at 1 year and subsequent follow-ups. 83 patients had 92 uncemented THJR in the designated time frame. 5 pts were lost to follow-up or died within 12 months after operation leaving 78 patients and 87 hips for assessment. Average pre-op HHS 40.6 (13.1–64.6) and Charnley Classification noted (A 55.4 %: B 30.4%: C 14.1%). 12/87 (13.8%) hips had subsidence > 2mm (2 – 18mm) noted at 1 year radiographs. Average HHS for those with >2mm subsidence was 89.4 (69.7–100; median 93.9) compared to 90.7 (64.7 – 100; median 91.9) for those with < 2mm subsidence. 4 patients underwent revision procedures during follow-up period, all for periprosthetic fracture following falls. In appropriately selected patients over 75 years of age, the presence of subsidence in uncemented femoral components does not seem to result in poorer outcome measures


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_22 | Pages 49 - 49
1 Dec 2016
Paprosky W
Full Access

As the number of patients who have undergone total hip arthroplasty rises, the number of patients who require surgery for a failed total hip arthroplasty is also increasing. Reconstruction of the failed femoral component in revision total hip arthroplasty can be challenging from both a technical perspective and in preoperative planning. With multiple reconstructive options available, it is helpful to have a classification system which guides the surgeon in selecting the appropriate method of reconstruction. We have developed a classification of femoral deficiency and an algorithmic approach to femoral reconstruction is presented. Type I: Minimal loss of metaphyseal cancellous bone with an intact diaphysis. Often seen when conversion of a cementless femoral component without biological ingrowth surface requires revision. Type II: Extensive loss of metaphyseal cancellous bone with an intact diaphysis. Often encountered after the removal of a cemented femoral component. Type IIIA: The metaphysis is severely damaged and non-supportive with more than four centimeters of intact diaphyseal bone for distal fixation. This type of defect is commonly seen after removal of grossly loose femoral components inserted with first generation cementing techniques. Type IIIB: The metaphysis is severely damaged and non-supportive with less than four centimeters of diaphyseal bone available for distal fixation. This type of defect is often seen following failure of a cemented femoral component that was inserted with a cement restrictor and cementless femoral components associated with significant distal osteolysis. Type IV: Extensive meta-diaphyseal damage in conjunction with a widened femoral canal. The isthmus is non-supportive


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 90 - 90
1 May 2011
Solgaard S Kjersgaard AG
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Introduction: Since 2000 all total hip replacements have been subjected to a continuous quality control. We report an increasing rate of postoperative fractures around uncemented femoral components after minimal or no trauma. Methods: Four to 6 weeks after the THR all patient files and radiographs are evaluated and demographic data, complications and radiographic position of the implant registered. Surgery was performed according to the manufacturer’s instructions, and full weight bearing was allowed. If a fracture occurred during the first postoperative weeks a further analysis of the case was performed. Results: During the 9 years 3.295 primary total hip replacements were performed. In the period the use of uncemented THR increased from 41% to 99%. Totally 69 fractures in 2.408 uncemented THR’s (2.9%) were registered, and 28 of these were of the proksimal split fracture type occurring without any previous trauma. The fractures occurred after a few days up to 4 weeks after surgery and were characterised by a vertical femoral fracture from the calcar to the medial femoral region 5 to 7 cm below the lesser trochanter. All cases were seen in women, but were not correlated to age, BMI or previous femoral neck fracture. In most cases treatment was internal fixation with a trochanteric grip and cables and insertion of a new uncemented femoral component. Conclusion: The increased use of uncemented femoral components implies a substantial risk of subtrochanteric femoral fracture. The cause of these fractures is unknown, but probably multifactorial. It could be due to a mismatch between the instruments and the prosthesis, to undiagnosed weakness of the bone, or to the vigorous mobilisation made possible by the effective modern treatment of postoperative pain


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_III | Pages 253 - 253
1 Jul 2011
MacDonald SJ Barrack RL Rosenzweig S Guerin JF McCalden RW Bohm E Bourne RB Rorabeck CH
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Purpose: There are two broad-based categories of cementless femoral components performed during total hip arthroplasty: proximally coated versus fully porous coated. While both have enjoyed widespread clinical applications, there remains debate regarding differences in clinical outcome scores, relative incidence of thigh pain and the development of stress shielding. The purpose of this study was to investigate these variables in a multi-center prospective randomized blinded clinical trial. Method: Between three centers 388 patients were enrolled in this clinical trial. 198 patients received a proximally coated tapered cementless femoral component (Synergy, Smith and Nephew, Memphis) and 190 patients received a fully porous coated cementless femoral component (Prodigy, Depuy, Warsaw). Patients were evaluated pre-operatively, at 3, 6, 12 months and annually thereafter, with multiple validated outcome measures including WOMAC, SF12, HSS, UCLA activity and thigh pain scores. A cohort of 72 patients underwent preoperative and postoperative DEXA scanning. Results: 367 patients had a minimum of 2 years follow-up (average 6.4 years). There were no differences in age at surgery, BMI, or pre-operative clinical outcome scores (WOMAC, SF12, HSS, UCLA activity, thigh pain) between groups. There were no differences in any post-operative clinical outcome scores at any interval of follow-up. There were no differences in incidence of thigh pain between groups at any time. The only measurable difference between study groups was in bone mineral density evaluation. Bone density change in Gruen zone 7 was 23.7% with the Prodigy stem and 15.3% with the Synergy stem (p=0.011). Conclusion: Both fully porous coated and proximally porous coated cementless stems performed well, with no clinical differences at a minimum of 2 years follow-up. Only bone mineral density evaluations could detect any differences between these femoral components designs


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_9 | Pages 72 - 72
1 Oct 2020
Howard JL Williams HA Lanting BA Teeter MG
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Background. In recent years, the use of modern cementless implants in total knee arthroplasty has been increasing in popularity. These implants take advantage of new technologies such as additive manufacturing and potentially provide a promising alternative to cemented implant designs. The purpose of this study was to compare implant migration and tibiofemoral contact kinematics of a cementless primary total knee arthroplasty (TKA) implanted using either a gap balancing (GB) or measured resection (MR) surgical technique. Methods. Thirty-nine patients undergoing unilateral TKA were recruited and assigned based on surgeon referral to an arthroplasty surgeon who utilizes either a GB (n = 19) or a MR (n = 20) surgical technique. All patients received an identical fixed-bearing, cruciate-retaining beaded peri-apatite coated cementless femoral component and a pegged highly porous cementless tibial baseplate with a condylar stabilizing tibial insert. Patients underwent a baseline radiostereometric analysis (RSA) exam at two weeks post-operation, with follow-up visits at six weeks, three months, six months, and one year post-operation. Migration including maximum total point motion (MTPM) of the femoral and tibial components was calculated over time. At the one year visit patients also underwent a kinematic exam using the RSA system. Results. Mean MTPM of the tibial component at one year post-operation was not different (mean difference = 0.09 mm, p = 0.980) between the GB group (0.85 ± 0.37 mm) and the MR group (0.94 ± 0.41 mm). Femoral component MTPM at one year post-operation was also not different (mean difference = 0.27 mm, p = 0.463) between the GB group (0.62 ± 0.34 mm) and the MR group (0.89 ± 0.44 mm). Both groups displayed a lateral pivot pattern with similar frequencies of condylar separation. Conclusion. There was no difference in implant migration and kinematics of a single-radius, cruciate retaining cementless TKA performed using a GB or MR surgical technique. The magnitude of migration suggests there is no risk of early loosening. The results provide support for the use of a cementless TKA as a viable alternative to cemented fixation


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 532 - 533
1 Aug 2008
Bailie A Kalairajah Y Forster M Spriggins A
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Introduction: A cementless femoral implant is currently available for hip resurfacing with several theoretical advantages over cemented fixation, one of which is a potential reduction in systemic emboli. A prospective study was undertaken to evaluate the occurrence of systemic emboli using a cementless femoral component for hip resurfacing in comparison to cemented femoral fixation. Methods: Between November 2004 and December 2005 patients scheduled for elective hip resurfacing for osteoarthritis were consented to undergo hip resurfacing using a cemented femoral component (Articular Surface Replacement or Birmingham Hip Resurfacing) or a cementless femoral component (Bi-coat Cormet Hip Resurfacing). Each case was randomised to femoral venting or no femoral venting. Intra-operative monitoring with a Transcranial Doppler device was used to identify and record systemic emboli throughout each case. Demographic and peri-operative data were collected including mental score and vital observations at day 1 and day 3, and blood loss. Results: 8 patients (5 vented, 3 unvented) underwent cemented resurfacing and 7 patients (4 vented, 3 unvented) had cementless resurfacing. There was no difference between the two groups for age (mean 56yrs), gender, weight, or ASA status. The mean number of significant emboli (> 12dB) in the cemented group was 8.1 and in the cementless group was 1.7 (significant, p=0.009). Peri-operatively both groups were similar for vital observations, haemoglobin, mental scores and SaO. 2. Venting did not influence rate of emboli. However, venting was independently associated with significantly higher drainage (mean 604mls compared to 335mls without venting, p=0.018). Discussion: This study has shown significantly less systemic emboli occur with the use of a cementless femoral component during hip resurfacing in comparison to a cemented implant. We propose this is due to intra-osseus pressure generated when using cement. The number of emboli is unaffected by femoral venting, but more blood loss occurs after venting


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_15 | Pages 93 - 93
1 Aug 2017
Paprosky W
Full Access

As the number of patients who have undergone total hip arthroplasty rises, the number of patients who require surgery for a failed total hip arthroplasty is also increasing. It is estimated that 183,000 total hip replacements were performed in the United States in the year 2000 and that 31,000 of these (17%) were revision procedures. Reconstruction of the failed femoral component in revision total hip arthroplasty can be challenging from a technical perspective and in pre-operative planning. With multiple reconstructive options available, it is helpful to have a classification system which guides the surgeon in selecting the appropriate method of reconstruction. A classification of femoral deficiency has been developed and an algorithmic approach to femoral reconstruction is presented. Type I:. Minimal loss of metaphyseal cancellous bone with an intact diaphysis. Often seen when conversion of a cementless femoral component without biological ingrowth surface requires revision. Type II: Extensive loss of metaphyseal cancellous bone with an intact diaphysis. Often encountered after the removal of a cemented femoral component. Type IIIA: The metaphysis is severely damaged and non-supportive with more than 4cm of intact diaphyseal bone for distal fixation. This type of defect is commonly seen after removal of grossly loose femoral components inserted with first generation cementing techniques. Type IIIB: The metaphysis is severely damaged and non-supportive with less than 4cm of diaphyseal bone available for distal fixation. This type of defect is often seen following failure of a cemented femoral component that was inserted with a cement restrictor and cementless femoral components associated with significant distal osteolysis. Type IV: Extensive meta-diaphyseal damage in conjunction with a widened femoral canal. The isthmus is non-supportive. An extensively coated, diaphyseal filling component reliable achieves successful fixation in the majority of revision femurs. The surgical technique is straightforward and we continue to use this type of device in the majority of our revision total hip arthroplasties. However, in the severely damaged femur (Type IIIB and Type IV), other reconstructive options may provide improved results. Type IIIB:. Based on the poor results obtained with a cylindrical, extensively porous coated implant (with 4 of 8 reconstructions failing), our preference is a modular, cementless, tapered stem with flutes for obtaining rotational stability. Excellent results have been reported with this type of implant and by virtue of its tapered design, excellent initial axial stability can be obtained even in femurs with a very short isthmus. Subsidence has been reported as a potential problem with this type of implant and they can be difficult to insert. However, with the addition of modularity to many systems that employ this concept of fixation, improved stability can be obtained by impaction of the femoral component as far distally as needed while then building up the proximal segment to restore appropriate leg length. Type IV:. The isthmus is completely non-supportive and the femoral canal is widened. Cementless fixation cannot be reliably used in our experience, as it is difficult to obtain adequate initial implant stability that is required for osseointegration. Reconstruction can be performed with impaction grafting if the cortical tube of the proximal femur is intact. However, this technique can be technically difficult to perform, time consuming and costly given the amount of bone graft that is often required. Although implant subsidence and peri-prosthetic fractures (both intra-operatively and post-operatively) have been associated with this technique, it can provide an excellent solution for the difficult revision femur where cementless fixation cannot be utilised. Alternatively, an allograft-prosthesis composite can be utilised for younger patients in an attempt to reconstitute bone stock and a proximal femoral replacing endoprosthesis used for more elderly patients


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_7 | Pages 49 - 49
1 Apr 2017
Paprosky W
Full Access

As the number of patients who have undergone total hip arthroplasty rises, the number of patients who require surgery for a failed total hip arthroplasty is also increasing. Reconstruction of the failed femoral component in revision total hip arthroplasty can be challenging from both a technical perspective and in pre-operative planning. With multiple reconstructive options available, it is helpful to have a classification system which guides the surgeon in selecting the appropriate method of reconstruction. Type I: Minimal loss of metaphyseal cancellous bone with an intact diaphysis. Often seen when conversion of a cementless femoral component without biological ingrowth surface requires revision. Type II: Extensive loss of metaphyseal cancellous bone with an intact diaphysis. Often encountered after the removal of a cemented femoral component. Type IIIA: The metaphysis is severely damaged and non-supportive with more than 4 cm of intact diaphyseal bone for distal fixation. This type of defect is commonly seen after removal of grossly loose femoral components inserted with first generation cementing techniques. Type IIIB: The metaphysis is severely damaged and non-supportive with less than 4 cm of diaphyseal bone available for distal fixation. This type of defect is often seen following failure of a cemented femoral component that was inserted with a cement restrictor and cementless femoral components associated with significant distal osteolysis. Type IV: Extensive meta-diaphyseal damage in conjunction with a widened femoral canal. The isthmus is non-supportive. Based on our results, the following reconstructive algorithm is recommended for femoral reconstruction in revision total hip arthroplasty. An extensively coated, diaphyseal filling component reliably achieves successful fixation in the majority of revision femurs and the surgical technique is straightforward. However, in the severely damaged femur (Type IIIB and Type IV), other reconstructive options may provide improved results. Type I: Cemented or cementless fixation can be utilised. If cemented fixation is selected, great care must be taken in removing the neo-cortex often encountered to allow for appropriate cement intrusion into the remaining cancellous bone. Type II: In this cohort of patients, successful fixation was achieved using a diaphyseal fitting, extensively porous coated implant. However, as the metaphysis is supportive, a cementless implant that achieves primary fixation in the metaphysis can be utilised. Type IIIA: An extensively coated stem of adequate length is utilised to ensure that more than 4 cm of scratch fit is obtained in the diaphysis. Type IIIB: Our present preference is a modular, cementless, tapered stem with flutes for obtaining rotational stability. Type IV: Cementless fixation cannot be reliably used in our experience, as it is difficult to obtain adequate initial implant stability that is required for osseointegration. Reconstruction can be performed with impaction grafting if the cortical tube of the proximal femur is intact. However, this technique can be technically difficult to perform, time consuming and costly given the amount of bone graft that is often required. Although implant subsidence and peri-prosthetic fractures (both intra-operatively and post-operatively) have been associated with this technique, it can provide an excellent solution for the difficult revision femur where cementless fixation cannot be utilised. Alternatively, an allograft-prosthesis composite can be utilised for younger patients in an attempt to reconstitute bone stock and a proximal femoral replacing endoprosthesis used for more elderly patients


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 10 - 10
1 Feb 2020
Haffner N Auersperg V Mercer S Koenigshofer M Rattinger H Ritschl P
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INTRODUCTION. Cementless femoral component designs supplemented with hydroxyapatite (HA) coating have been hypothesised to enhance osseointegration, thereby improving stability and clinical outcomes. We herein offer interim results at 5 years from a prospective, multi-centre study of a femoral stem (SL-PLUS™ Hip Stem Prosthesis), forged from titanium alloy (Ti6Al7Nb) and consisting of a titanium plasma sprayed coating (0.3mm) with an additional 0.05mm layer of HA. METHODS. Investigators at 2 centres enrolled patients between 18–75 years of age who underwent primary total hip arthroplasty (THA) with this HA-coated stem. The study's primary outcome was the clinical efficacy of the stem, as measured by the Harris Hip Score (HHS), Western Ontario & McMaster Universities Osteoarthritis (WOMAC) Score calculated out of Hip Disability and Osteoarthritis Outcome Score (HOOS), and the EuroQol EQ-5D-3L index score and visual analogue scale (VAS). Its secondary outcomes included a radiographic assessment of implant position and fixation, and overall safety, as measured by intraoperative/early postoperative complications and survivorship calculated using Kaplan-Meier estimates. RESULTS. Ninety-three patients (94 hips) were enrolled in the study. At the time of surgery, the study population had a mean age of 60.1 years (standard deviation [SD], 8.4), a mean body mass index of 27.9 kg/m. 2. (SD, 4.75), and 54.8% were female. Indications for surgery include primary osteoarthritis (74.5%), dysplasia (17.5%), femoral head necrosis (6.4%), and other (2.1%). Patients were followed up through 5 years in the ongoing safety and performance analysis. Between preoperative baseline and final follow up, there were notable improvements in the mean scores for all primary clinical outcomes: HHS (51.6 to 91.4, respectively), WOMAC from HOOS (42.6 to 91.0, respectively), mean EQ-5D-3L index score (0.7 to 0.9, respectively), and EQ-5D-3L VAS (54.7 to 80.2, respectively). The majority of patients rated their satisfaction as excellent (84.2% of treated hips), with an additional 14.5% of treated hips being mostly satisfied. Five years after surgery, radiographic findings showed an overall stability of the device, with 100% unchanged stem positions (no movement in varus/valgus or subsidence) and no stem was classified as loose. Intraoperative complications were observed in 3 patients (3.2%), consisting of 2 cases of trochanteric fracture and 1 case of leg lengthening. There were no general early postoperative complications reported in any patient. Two revision surgeries of the study device were reported, both due to infection, resulting in a survivorship of 97.5% (95% confidence interval: 90.3% – 99.4%) at 5 years. CONCLUSION. These results confirm the safety and efficacy of this HA-coated femoral stem at 5 years. All clinical outcomes showed significant improvement between baseline and midterm follow up, with mean HHS in particular meeting the 90-point range considered “excellent.” Additionally, revision rates met the accepted benchmarks for a successful THA device. For any figures or tables, please contact authors directly


Bone & Joint Open
Vol. 4, Issue 5 | Pages 306 - 314
3 May 2023
Rilby K Mohaddes M Kärrholm J

Aims

Although the Fitmore Hip Stem has been on the market for almost 15 years, it is still not well documented in randomized controlled trials. This study compares the Fitmore stem with the CementLeSs (CLS) in several different clinical and radiological aspects. The hypothesis is that there will be no difference in outcome between stems.

Methods

In total, 44 patients with bilateral hip osteoarthritis were recruited from the outpatient clinic at a single tertiary orthopaedic centre. The patients were operated with bilateral one-stage total hip arthroplasty. The most painful hip was randomized to either Fitmore or CLS femoral component; the second hip was operated with the femoral component not used on the first side. Patients were evaluated at three and six months and at one, two, and five years postoperatively with patient-reported outcome measures, radiostereometric analysis, dual-energy X-ray absorptiometry, and conventional radiography. A total of 39 patients attended the follow-up visit at two years (primary outcome) and 35 patients at five years. The primary outcome was which hip the patient considered to have the best function at two years.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 100 - 100
1 Apr 2019
Kreuzer S Pierrepont J Stambouzou C Walter L Marel E Solomon M Shimmin A McMahon S Bare J
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Introduction. Appropriate femoral stem anteversion is an important factor in maintaining stability and maximizing the performance of the bearing after total hip replacement (THR). The anteversion of the native femoral neck has been shown to have a significant effect on the final anteversion of the stem, particularly with a uncemented femoral component. The aim of this study was to quantify the variation in native femoral neck anteversion in a population of patients requiring total hip replacement. Methods. Pre-operatively, 1215 patients received CT scans as part of their routine planning for THR. Within the 3D planning, each patient's native femoral neck anteversion, measured in relation to the posterior condyles of the knee, was determined. Patients were separated into eight groups based upon gender and age. Males and females were divided by those under 55 years of age, those aged 55 to 64, 65 to 74 and those 75 or older. Results. The median anteversion in males was 12.7° (−27.1°–45.5°, IQR 6.0°–19.1°), compared to female anteversion of 16.0° (− 14.0°–54.5°, IQR 9.7°– 22.4°). These gender differences were statistically significant, p < 0.0001. Femoral anteversion in young males (<55) was significantly higher than in older males (>75), p=0.002. This age-related difference approached significance in females, p = 0.06. 14% of patients had extreme anteversion (<0° or >30°). Conclusions. The Native femoral neck anteversion in patients requiring THR is widely variable, with a range of over 80°. Females have more anteverted femurs than males. Femoral anteversion in young males was significantly higher than in older males. This age-related difference approached significance in females. Having an understanding of 3D patient morphology can greatly assist in pre-operative planning of THR, as post-op stem anteversion is likely influenced by the anteversion of the native femoral neck


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 144 - 144
1 Mar 2008
McAuley J Moore M Young A Engh C
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Purpose: Radiographic signs of osseointegration have been well established for cementless femoral components, but not for cementless acetabular components. At our institution using principles similar to those applied to cementless femoral components, we have observed apparent radiographic signs of osseointegration of porous-coated cups. We then hypothesized that these signs could be used to predict bone ingrowth of porous-coated acetabular components. Methods: In a series of 119 total hip arthroplasties with porous-coated cementless cups, we reviewed post-primary and prerevision serial radiographs and proposed five radiographic signs for detecting osseointegration of a porous-coated acetabular component: absence of radiolucent lines, presence of a superolateral buttress, medial stress shielding, radial trabeculae, and an infero-medial buttress. We compared the predictability of each sign to intraoperative findings of cup stability and measured the sensitivity, specificity, and intra-observer agreement of each sign. Results: . In our population, ninety-eight cups had three to five radiographic signs of osseointegration; of these, ninety-five cups (97%) were found to be bone-ingrown at the revision operation. Conversely, twelve cups had only one or no sign; of these, ten (83%) were clinically unstable at the revision operation. Conclusions: We concluded these five, readily detectable signs of acetabular osseointegration are very useful in predicting acetabular component stability found at surgery


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_10 | Pages 50 - 50
1 Jun 2018
Walter W
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We present a technique of single posterior longitudinal slot femorotomy. This technique allows the expansion of the metaphyseal-diaphyseal region of the proximal femur facilitating extraction of proximally coated uncemented femoral components while leaving the metaphysis and diaphysis intact. Since 1996 we have performed this technique in 18 revision total hip arthroplasties in 15 patients who had x-ray appearance of bony in-growth/on-growth and where found to have solidly ingrown stems at revision surgery. All were revised to a metaphyseal-fitting uncemented stem. At mean follow-up of 122.4 months, there were significant improvements in both pain and function. All revised stems achieved stable bony fixation. There were no complications due to this technique. No patient developed a limp or thigh pain post-operatively. There have been no re-revisions of the stem. With appropriate patient selection, this simple, reliable, and extensile technique is useful to assist in the extraction of uncemented proximally coated femoral components whether hydroxyapatite-coated or not


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_II | Pages 293 - 293
1 May 2010
Aldinger P Jung A Thomsen M Ewerbeck V Parsch D
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Introduction: THA in young and active patients remains a major challenge. Uncemented femoral components have been advocated in young patients, but there are only few reports with more than 10 years follow-up. Materials and Methods: We followed the first 153 consecutive implantations of an uncemented, straight femoral stem (CLS, Zimmer Inc, Warsaw, USA) in 141 patients. Mean time of follow-up evaluation was 17 years (range, 15–20 years), mean age at surgery was 47 years (23–55). Results: At follow-up, 20 patients (20 hips) had died, and 7 (7 hips) were lost to follow-up. 10 patients (10 hips) underwent femoral revision–1 for infection, 4 for periprosthetic fracture, and 5 for aseptic loosening of the stem. Overall survival was 91% at 17 years (95%-confidence limits, 88%-94%), survival with femoral revision for aseptic loosening as an end point was 95% (95%-confidence limits, 93%–98%). The mean Harris-Hip-Score at follow-up evaluation was 84 points. 116 hips were available for radiolographic evaluation. Radiolucent lines (< 2mm) in Gruen zones 1 and 7 were present in 12,9% (15 hips) and 13,8% (16 hips), respectively. Radiolucencies in zones 2–6 were found in 0,9% (1 hip) – 2,6% (3 hips) on ap x-rays. Only one case of distal osteolysis was found after a previous Wagner resurfacing. No case of severe femoral osteolysis was found at follow-up. Conclusions: The long-term results with this type of uncemented femoral component are encouraging and compare favorably with those achieved in primary cemented total hip arthroplasty in this group of young and active patients


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 51 - 51
1 Mar 2009
Aldinger P Jung A Ewerbeck V Parsch D
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Introduction: THA in young and active patients remains a major challenge. Uncemented femoral components have been advocated in young patients, but there are only few reports with more than 10 years follow-up. Materials and Methods: We followed the first 153 consecutive implantations of an uncemented, straight femoral stem (CLS, Zimmer Inc, Warsaw, USA) in 141 patients. Mean time of follow-up evaluation was 17 years (range, 15 – 20 years), mean age at surgery was 47 years (23–55). Results: At follow-up, 20 patients (20 hips) had died, and 7 (7 hips) were lost to follow-up. 10 patients (10 hips) underwent femoral revision- 1 for infection, 4 for periprosthetic fracture, and 5 for aseptic loosening of the stem. Overall survival was 91% at 17 years (95%-confidence limits, 88%–94%), survival with femoral revision for aseptic loosening as an end point was 95% (95%-confidence limits, 93% – 98%). The mean Harris-Hip-Score at follow-up evaluation was 84 points. 116 hips were available for radiolographic evaluation. Radiolucent lines (< 2mm) in Gruen zones 1 and 7 were present in 12,9% (15 hips) and 13,8% (16 hips), respectively. Radiolucencies in zones 2 – 6 were found in 0,9% (1 hip) – 2,6% (3 hips) on ap x-rays. Only one case of distal osteolysis was found after a previous Wagner resurfacing. No case of severe femoral osteolysis was found at follow-up. Conclusions: The long-term results with this type of uncemented femoral component are encouraging and compare favorably with those achieved in primary cemented total hip arthroplasty in this group of young and active patients