Aims. Uncemented implants are now commonly used at reimplantation of a two-stage revision total hip arthoplasty (THA) following periprosthetic joint infection (PJI). However, there is a paucity of data on the performance of the most commonly used uncemented femoral implants – modular fluted tapered (MFT) femoral components – in this setting. This study evaluated implant survival, radiological results, and clinical outcomes in a large cohort of reimplantation THAs using MFT components. Methods. We identified 236 reimplantation THAs from a single tertiary care academic institution from September 2000 to September 2020. Two designs of MFT femoral components were used as part of an established two-stage exchange protocol for the treatment of PJI. Mean age at reimplantation was 65 years (SD 11), mean BMI was 32 kg/m. 2. (SD 7), and 46% (n = 109) were female. Mean follow-up was seven years (SD 4). A competing risk model accounting for death was used. Results. The 15-year cumulative incidence of any revision was 24%. There were 48 revisions, with the most common reasons being dislocation (n = 25) and infection (n = 16). The 15-year cumulative incidence of any reoperation was 28%. Only 13 revisions involved the fluted tapered component (FTC), for a 15-year cumulative incidence of any FTC revision of 8%. Only two FTCs were revised for aseptic loosening, resulting in a 15-year cumulative incidence of FTC revision for aseptic loosening of 1%. Stem subsidence ≥ 5 mm occurred in 2% of unrevised cases. All stems were radiologically stable at most recent follow-up. Mean Harris Hip Score was 69 (SD 20) at most recent follow-up. Conclusion. This series demonstrated that MFT components were durable and reliable in the setting of two-stage reimplantation THA for infection. While the incidence of aseptic loosening was very low, the incidence of any revision was 24% at 15 years, primarily due to dislocation and recurrent PJI. Cite this article: Bone Joint J 2024;106-B(5 Supple B):125–132

Non-modular tapered fluted, titanium stems are available for use in femoral revision. The combination of taper and flutes on the stem provides axial and rotational stability, respectively. The material and surface properties of the stem promotes bone on-growth. If the surgeon is confident and reasonably experienced in the surgical use of this sort of design and the case is relatively straightforward, a non-modular design is effective. It also potentially reduces implant inventory, and circumvents the potential problems of taper junction corrosion and fatigue fracture. There are reports of excellent survival, good clinical and functional results and evidence of subsequent increase in proximal bone stock. Cite this article: Bone Joint J 2014;96-B(11 Suppl A):56–9

Revision total hip arthroplasty (THA) is challenging when there is severe loss of bone in the proximal femur. The purpose of this study was to evaluate the clinical and radiographic outcomes of revision THA in patients with severe proximal femoral bone loss treated with a fluted, tapered, modular femoral component. Between January 1998 and December 2004, 92 revision THAs were performed in 92 patients using a single fluted, tapered, modular femoral stem design. Pre-operative diagnoses included aseptic loosening, infection and peri-prosthetic fracture. Bone loss was categorised pre-operatively as Paprosky types III-IV, or Vancouver B3 in patients with a peri-prosthetic fracture. The mean clinical follow-up was 6.4 years (2 to 12). A total of 47 patients had peri-operative complications, 27 of whom required further surgery. However, most of these further operations involved retention of a well-fixed femoral stem, and 88/92 femoral components (97%) remained in situ. Of the four components requiring revision, three were revised for infection and were well fixed at the time of revision; only one (1%) was revised for aseptic loosening. The most common complications were post-operative instability (17 hips, 19%) and intra-operative femoral fracture during insertion of the stem (11 hips, 12%). Diaphyseal stress shielding was noted in 20 hips (22%). There were no fractures of the femoral component. At the final follow-up 78% of patients had minimal or no pain. . Revision THA in patients with extensive proximal femoral bone loss using the Link MP fluted, tapered, modular stem led to a high rate of osseointegration of the stem at mid-term follow-up. Cite this article: Bone Joint J 2015; 97-B:312–17

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. Although good clinical outcomes have been reported for monolithic tapered, fluted, titanium stems (TFTS), early results showed high rates of subsidence. Advances in stem design may mitigate these concerns. This study reports on the use of a current monolithic TFTS for a variety of indications. Methods. A multi-institutional retrospective study of all consecutive total hip arthroplasty (THA) and revision total hip arthroplasty (rTHA) patients who received the monolithic TFTS was conducted. Surgery was performed by eight fellowship-trained arthroplasty surgeons at four institutions. A total of 157 hips in 153 patients at a mean follow-up of 11.6 months (SD7.8) were included. Mean patient age at the time of surgery was 67.4 years (SD 13.3) and mean body mass index (BMI) was 28.9 kg/m. 2. (SD 6.5). Outcomes included intraoperative complications, one-year all-cause re-revisions, and subsidence at postoperative time intervals (two weeks, six weeks, six months, nine months, and one year). Results. There were eight intraoperative complications (4.9%), six of which were intraoperative fractures; none occurred during stem insertion. Six hips (3.7%) underwent re-revision within one year; only one procedure involved removal of the prosthesis due to infection. Mean total subsidence at latest follow-up was 1.64 mm (SD 2.47). Overall, 17 of 144 stems (11.8%) on which measurements could be performed had >5 mm of subsidence, and 3/144 (2.1%) had >10 mm of subsidence within one year. A univariate regression analysis found that additional subsidence after three months was minimal. A multivariate regression analysis found that subsidence was not significantly associated with periprosthetic fracture as an indication for surgery, the presence of an extended trochanteric osteotomy (ETO), Paprosky classification of femoral bone loss, stem length, or type of procedure performed (i.e. full revision vs conversion/primary). Conclusion. Advances in implant design, improved trials, a range of stem lengths and diameters, and high offset options mitigate concerns of early subsidence and dislocation with monolithic TFTS, making them a valuable option for femoral revision. Cite this article: Bone Joint J 2020;102-B(2):191–197

Aims. Radiostereometric analysis (RSA) allows an extremely accurate measurement of early micromotion of components following arthroplasty. . Patients and Methods. In this study, RSA was used to measure the migration of 11 partially cemented fluted pegged glenoid components in patients with osteoarthritis who underwent total shoulder arthroplasty using an improved surgical technique (seven men, four women, mean age 68). Patients were evaluated clinically using the American Shoulder and Elbow Surgeons (ASES) and Constant-Murley scores and by CT scans two years post-operatively. . Results. There were two patterns of migration, the first showing little, if any, migration and the second showing rotation by > 6° as early as three months post-operatively. At two years, these two groups could be confirmed on CT scans, one with osseointegration around the central peg, and the second with cystic changes. Patients with osteolysis around the central peg were those with early migration and those with osseointegration had minimal early migration. Both groups,however,had similar clinical results. . Conclusion. Rapid early migration associated with focal lucency and absence of osseointegration was observed in three of 11 glenoid components, suggesting that lack of initial stability leads to early movement and failure of osseointegration. Cite this article: Bone Joint J 2017;99-B:674–9

Tapered, fluted, modular, titanium stems have a long history in Europe and are increasing in popularity in North America. We have reviewed the results at our institution looking at stem survival and clinical outcomes. Radiological outcomes and quality of life assessments have been performed and compared to cylindrical non-modular cobalt chromium stems. Survival at five years was 94%. This fell to 85% at ten years due to stem breakage with older designs. Review of radiology showed maintenance or improvement of bone stock in 87% of cases. Outcome scores were superior in tapered stems despite worse pre-operative femoral deficiency. Tapered stems have proved to be a useful alternative in revision total hip arthroplasty across the spectrum of femoral bone deficiency

We reviewed 25 patients in whom a MUTARS megaprosthesis with a conical fluted stem had been implanted. There were three types of stem: a standard stem was used in 17 cases (three in the proximal femur, nine in the distal femur and five proximal tibia), a custom-made proximal femoral stem in four cases and a custom-made distal femoral stem in four cases. The mean age of the patients was 40.1 years (17 to 70) and the mean follow-up was for 2.5 years (0.9 to 7.4). At follow-up two patients had died from their disease: one was alive with disease and 22 were disease-free. One of 23 prostheses had been removed for infection and another revised to a cemented stem. The mean Musculoskeletal Tumor Society score was 24.9 (12 to 30) and the mean Karnofsky index was 82% (60% to 100%). There was no radiological evidence of loosening or subsidence. Stem stress shielding was seen in 11 patients and was marked in five of these. There were five complications, rupture of the extensor mechanism of the knee after extra-articular resection in two patients, deep venous thrombosis in one, septic loosening in one, and dislocation of the hip in one. The survival rate after seven years was 87% (95% confidence interval (CI) 83 to 91) for the patients and 95% (95% CI 91 to 99) for the megaprosthesis. A longer follow-up is needed to confirm these encouraging results

Tapered, fluted, modular, titanium stems are increasingly popular in the operative management of Vancouver B2 and selected B3 peri-prosthetic femoral fractures. We have reviewed the results at our institution looking at stem survival and clinical outcomes and compared this with reported outcomes in the literature. Stem survival at a mean of 54 months was 96% in our series and 97% for combined published cases. Review of radiology showed maintenance or improvement of bone stock in 89% of cases with high rates of femoral union. Favourable clinical outcome scores have reported by several authors. No difference in survival or clinical scores was observed between B2 and B3 fractures. Tapered stems are a useful option in revision for femoral fracture across the spectrum of femoral bone deficiency. Cite this article: Bone Joint J 2013;95-B, Supple A:17–20

We report our experience of revision total hip replacement (THR) using the Revitan curved modular titanium fluted revision stem in patients with a full spectrum of proximal femoral defects. A total of 112 patients (116 revisions) with a mean age of 73.4 years (39 to 90) were included in the study. The mean follow-up was 7.5 years (5.3 to 9.1). A total of 12 patients (12 hips) died but their data were included in the survival analysis, and four patients (4 hips) were lost to follow-up. The clinical outcome, proximal bone regeneration and subsidence were assessed for 101 hips. The mean Harris Hip Score was 88.2 (45.8 to 100) after five years and there was an increase of the mean Barnett and Nordin-Score, a measure of the proximal bone regeneration, of 20.8 (-3.1 to 52.7). Five stems had to be revised (4.3%), three (2.9%) showed subsidence, five (4.3%) a dislocation and two of 85 aseptic revisions (2.3%) a periprosthetic infection. . At the latest follow-up, the survival with revision of the stem as the endpoint was 95.7% (95% confidence interval 91.9% to 99.4%) and with aseptic loosening as the endpoint, was 100%. Peri-prosthetic fractures were not observed. We report excellent results with respect to subsidence, the risk of fracture, and loosening after femoral revision using a modular curved revision stem with distal cone-in-cone fixation. A successful outcome depends on careful pre-operative planning and the use of a transfemoral approach when the anatomy is distorted or a fracture is imminent, or residual cement or a partially-secured existing stem cannot be removed. The shortest appropriate stem should, in our opinion, be used and secured with > 3 cm fixation at the femoral isthmus, and distal interlocking screws should be used for additional stability when this goal cannot be realised. Cite this article: Bone Joint J 2014;96-B:889–95

If a surgeon is faced with altered lesser trochanter anatomy when revising the femoral component in revision total hip replacement, a peri-prosthetic fracture, or Paprosky type IIIb or type IV femoral bone loss, a modular tapered stem offers the advantages of accurately controlling femoral version and length. The splines of the taper allow rotational control, and improve the fit in femoral canals with diaphyseal bone loss. In general, two centimetres of diaphyseal contact is all that is needed to gain stability with modular tapered stems. By allowing the proximal body trial to rotate on a well-fixed distal segment during trial reduction, appropriate anteversion can be obtained in order to improve intra-operative stability, and decrease the dislocation risk. However, modular stems should not be used for all femoral revisions, as implant fracture and corrosion at modular junctions can still occur.

Cite this article: Bone Joint J 2013;95-B, Supple A:95–7.

Aims. United Classification System (UCS) B2 and B3 periprosthetic fractures in total hip arthroplasties (THAs) have been commonly managed with modular tapered stems. No study has evaluated the use of monoblock fluted tapered titanium stems for this indication. This study aimed to evaluate the effects of a monoblock stems on implant survivorship, postoperative outcomes, radiological outcomes, and osseointegration following treatment of THA UCS B2 and B3 periprosthetic fractures. Methods. A retrospective review was conducted of all patients who underwent revision THA (rTHA) for periprosthetic UCS B2 and B3 periprosthetic fracture who received a single design monoblock fluted tapered titanium stem at two large, tertiary care, academic hospitals. A total of 72 patients met inclusion and exclusion criteria (68 UCS B2, and four UCS B3 fractures). Primary outcomes of interest were radiological stem subsidence (> 5 mm), radiological osseointegration, and fracture union. Sub-analysis was also done for 46 patients with minimum one-year follow-up. Results. For the total cohort, stem osseointegration, fracture union, and stem subsidence were 98.6%, 98.6%, and 6.9%, respectively, at latest follow-up (mean follow-up 27.0 months (SD 22.4)). For patients with minimum one-year of follow-up, stem osseointegration, fracture union, and stem subsidence were 97.8%, 97.8%, and 6.5%, respectively. Conclusion. Monoblock fluted stems can be an acceptable modality for the management of UCS B2 periprosthetic fractures in rTHAs due to high rates of stem osseointegration and survival, and the low rates of stem subsidence, and revision. Further research on the use of this stem for UCS B3 periprosthetic fractures is warranted to determine if the same conclusion can be made for this fracture pattern. Cite this article: Bone Jt Open 2023;4(8):551–558

We had previously reported on early outcomes on a new fluted, titanium, monobloc stem with a three degree taper that has been designed for challenging femoral reconstruction in the setting of extensive bone loss. The aim of this study was to report its mid-term clinical and radiographic outcomes. This is a retrospective review of prospectively collected data carried out at a single institution between Jan 2017 and Dec 2019. 85 femoral revisions were performed using a new tapered, fluted, titanium, monobloc (TFTM) revision stem. Complications, clinical and radiographic data were obtained from medical records and a locally maintained database. Clinical outcomes were assessed using the Oxford Hip Score (OHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). All post-operative radiographs were analysed for subsidence, osteolysis and femoral cortical bone remodelling. Mean follow-up was 60 months (range 28–84 months). Subsidence of 1.2 mm was noted in one patient. No cases of clinically significant subsidence (10 mm) were observed. At final follow-up, a statistically significant improvement was noted in functional outcome scores. The mean OHS preoperatively and at final follow-up were 24 (SD 13) and 42 (SD15). p = 0.04 mean difference 18 (95% CI 15–22). The mean WOMAC scores preoperatively and at final follow-up were 62 (SD23) and 88 (SD7) respectively (p < 0.001, mean difference 26; 95% CI 21–34). No stem fractures were noted within the follow-up period. Two patients had revision of the stem's one for infection and another for persistent pain. Positive mid-term clinical and radiological outcomes have been observed with this tapered, fluted, titanium, monobloc stem. Based on these results, this implant may be considered as a viable option in the majority of uncemented femoral revisions

Aims. The risk of mechanical failure of modular revision hip stems is frequently mentioned in the literature, but little is currently known about the actual clinical failure rates of this type of prosthesis. The current retrospective long-term analysis examines the distal and modular failure patterns of the Prevision hip stem from 18 years of clinical use. A design improvement of the modular taper was introduced in 2008, and the data could also be used to compare the original and the current design of the modular connection. Methods. We performed an analysis of the Prevision modular hip stem using the manufacturer’s vigilance database and investigated different mechanical failure patterns of the hip stem from January 2004 to December 2022. Results. Two mechanical failure patterns were identified: fractures in the area of the distal fluted profile (distal stem fracture) and failure of the modular taper (modular fracture). A failure rate of 0.07% was observed for distal stem fracture, and modular fracture rates of 1.74% for the original and 0.013% for the current taper design. Conclusion. A low risk of mechanical failure for both fracture types was observed compared to other known complications in revision hip arthroplasty. In addition, the data show that a design change did significantly reduce the risk of a modular fracture. Cite this article: Bone Joint J 2024;106-B(2):151–157

There is a paucity of long-term data on modular fluted tapered (MFT) stems for two-stage reimplantation following periprosthetic joint infection (PJI). The purpose of this study was to evaluate implant survivorship, radiographic results, and clinical outcomes in a large cohort of reimplantation THAs using MFT stems. We identified 236 reimplantation THAs from a single tertiary care academic institution from 2000 to 2020. Two designs of MFT stems were used as part of an established two-stage exchange protocol for the treatment of PJI. Mean age at reimplantation was 65 years, mean BMI was 32 kg/m. 2. , and 46% were female. Median stem diameter was 19 mm, and median stem length was 195 mm. Mean follow-up was 7 years. A competing risk model accounting for death was utilized. The 15-year cumulative incidence of any revision was 24%. There were 48 revisions, with the most common reasons being dislocation (n=25) and PJI (n=16). The 15-year cumulative incidence of any reoperation was 28%. Only 13 revisions involved the fluted tapered portion of the component (FTC), for a 15-year cumulative incidence of any FTC revision of 8%. Only 2 FTCs were revised for aseptic loosening, resulting in a 15-year cumulative incidence of FTC revision for aseptic loosening of 1%. Stem subsidence >5 mm occurred in 2% of unrevised cases, and all stems were radiographically stable at most recent follow-up. Mean HHS was 77 at most recent follow-up. This series demonstrated that MFT stems were durable and reliable even in the setting of two-stage reimplantation for infection. While the incidence of aseptic loosening was very low, the incidence of any revision was 24% at 15 years, primarily caused by dislocation and recurrent PJI. Level of Evidence: IV

Tapered fluted grit-blasted modular stems have now become established as a successful method of femoral revision. The success of these stems is predicated on obtaining axial stability by milling the femur to a cone and then inserting the tapered prosthesis into that cone. Torsional stability is gained by flutes that cut into the diaphysis. By having modular proximal segments of different lengths, the leg length, offset, and anteversion can be adjusted after the distal stem is fixed. This maximises the chance for the stem to be driven into the canal to whatever level provides maximum stem stability. Modular fluted tapered stems have the potential benefits of being made of titanium and hence being both bone friendly and also having a modulus of elasticity closer to that of bone. They have a well-established high rate of fixation. Drawbacks include the risk of fracture of modular junctions and tapers, and difficulty of extraction. The indications for the use of these implants vary among surgeons, but the implants are suitable for use in a wide variety of bone loss categories. Non-modular fluted tapered stems also can gain excellent fixation, but are less versatile and in most practices are used for selected simpler revisions. Results from a number of institutions in North America and Europe demonstrate high rates of implant fixation. In a recently published paper from Mayo Clinic, the 10-year survivorship, free of femoral aseptic loosening revision, of a modular fluted tapered stem was 98% and the stem performed well across a wide range of bone deficiencies. The technique of implantation will be described in a video during the presentation

Local anatomical abnormalities vary in congenital hip disease patients. Authors often present early to mid-term total hip arthroplasty clinical outcomes using different techniques and implants randomly on patients with different types of the disease, making same conclusions difficult. We report long term outcomes (13 to 23 years) of the treatment of low and high dislocation cases (separately) with total hip arthroplasty using TM technology acetabular cups (Implex initially and then Zimmer) and short fluted conical (Zimmer) femoral stems. From 2000 to 2010, 418 congenital hip disease hip joints were treated in our department with total hip arthroplasty. According to Hartofilakidis et al's classification, 230 hips had dysplasia, 101 low dislocation, (group A) and 87 high dislocation (group B). Pre-operative and post-operative values, at regular intervals, of HHS, SF-12, WOMAC, OHS and HOOS were available for all patients. Patient, surgeon and implant related failures and complications were recorded for all patients. In all cases an attempt was made to restore hip center of rotation. In group A the average lengthening was 2.8 cm (range: 1 to 4.2) and in group B 5.7 cm (range: 4.2 to 11). In both groups, no hips were revised due to aseptic loosening of either the acetabular cup or the femoral stem. In group A, a cumulative success rate of 95.6% (95% confidence interval, 92.7% – 97.4%) and in group B a cumulative success rate of 94.8% (95% confidence interval, 92.6%–96.9%) was recorded, at 20 years, with revision for any reason as an end point. No s.s. differences were found between groups when mean values of HHS, SF-12, WOMAC and OKS were compared. Satisfactory long-term clinical outcomes can be achieved in treating different types of congenital hip disease when appropriate surgical techniques combined with “game changing” implants are used

We sought to determine the short to medium-term clinical and radiographic outcomes using a short stem in young adults with a proximal femoral deformity (PFD). We prospectively studied 31 patients (35 hips) with PFDs treated with an uncemented primary THA using a short stem with cervicometaphyseal fixation between 2011–2018. There were 19 male (23 hips) and 12 female (12 hips) patients, with a mean BMI of 26.7±4.1 kg/m. 2. Twelve cases had a previous surgical procedure, and six of them were failed childhood osteotomies. Mean age of the series was 44±12 years, mean follow-up was 81±27 months and no patients were lost to follow-up. PFDs were categorized according to a modified Berry´s classification. Average preoperative leg-length discrepancy (LLD) was −16.3 mm (−50 to 2). At a mean time of 81 months of follow-up, survival rate was 97% taking revision of the stem for any reason and 100% for aseptic loosening as endpoints. No additional femoral osteotomy was required in any case. Average surgical time was 66 minutes (45 to 100). There was a significant improvement in the mHHS score when comparing preoperative and postoperative values (47.3±10.6 vs. 92.3±3.7, p=0.0001). Postoperative LLD was in average 1 mm (−9 to 18) (p=0.0001). According to Engh's criteria, all stems were classified as stable without signs of loosening. Postoperative complications included 1 pulmonary embolism, 1 neurogenic sciatic pain, 1 transient sciatic nerve palsy that recovered completely after six months, and 2 acute periprosthetic joint infections. One patient suffered a Vancouver B2 periprosthetic femoral fracture 45 days after surgery and was revised with a modular distally fixed uncemented fluted stem. A type 2B short stem evidenced promising outcomes at short to medium-term follow up in young adult patients with PFDs, avoiding the need for corrective osteotomies and a revision stem

Subsidence remains a concern when utilizing modern tapered fluted titanium (TFT) femoral stems and may lead to leg length discrepancy, impingement, instability and failure to obtain stem osseointegration. This study aims to compare stem subsidence across three modern TFT stems. Our secondary aim was to investigate the influence of bicortical contact or ‘scratch fit’ on subsidence, as well as the role of intraoperative imaging in maximizing this bicortical contact and preventing stem subsidence. A retrospective review of 271 hip arthroplasties utilizing modern TFT stems in a single institution was performed. Three stem designs were included in the analysis: one monoblock TFT stem (n=91) and two modular TFT stems (Modular A [n=90]; Modular B [n=90]). Patient demographics, Paprosky femoral bone loss classification, bi-cortical contact, utilization of intra-operative imaging and stem subsidence (comparison of initial post-operative radiograph to the latest follow up radiograph - minimum three months) were recorded. There was no statistically significant difference in the amount of subsidence between the three stems (Monoblock: 2.33mm, Modular A: 3.43mm, Modular B: 3.02mm; p=0.191). There was no statistical difference in subsidence >5mm between stems (Monoblock: 9.9%, Modular A: 22.2%, Modular B: 16.7%). Subgroup analysis based on femoral bone loss grading showed no difference in subsidence between stems. Increased bicortical contact was strongly associated with reduced subsidence (p=0.004). Intra-operative imaging was used in 46.5% (126/271) of cases; this was not correlated with bicortical contact (p=0.673) or subsidence (p=0.521). Across all groups, only two stems were revised for subsidence (0.7%). All three modern TFT stems were highly successful and associated with low rates of subsidence, regardless of modular or monoblock design. Surgeons should select the stem that they feel is most clinically appropriate

For over a decade, modular titanium fluted tapered (TFT) stems have demonstrated excellent clinical success for femoral revision total hip arthroplasty (THA) surgery. The aim of this study was to report the short-term outcomes of a novel modern monoblock TFT stem used for revision and complex primary THA with a minimum of 2 years follow-up. We identified 126 patients who received a single monoblock TFT stem - 26 patients for complex THA (failed fracture fixation) and 100 patients for revision THA. The reasons for revision THA included 40 for previous prosthetic joint infection (PJI), 42 for aseptic loosening, 9 for trunnionosis, 9 for periprosthetic fractures. The Paprosky grading for femoral bone loss at the time of surgery and the measured subsidence of femoral stems at 3 months follow-up were determined. We evaluated the number and indications for re-operations. The mean time from surgery was 3.9 years (range 2.0 to 6.9 years). A paired t-test analysis showed significant improvement from pre-operative versus post-operative clinical outcome scores (p<0.001) for HHS (38.76 +/- 15.24vs. 83.42 +/- 15.38), WOMAC (45.6 ± 19.0 vs. 69.9 ± 21.3) and SF-12 Physical component (31.7 ± 8.1 vs. 37.8 ± 11.3) and SF-12 Mental component (48.2 ± 12.2 vs. 51.6 ± 12.5). The Paprosky grading for femoral bone loss was Grade 1 (3.9%), Grade 2 (35.7%), Grade 3A (47.6%), Grade 3B (11.1%) and Grade 4 (1.6%) cases. There were 18 re-operations (14.7%) with 13 for PJI (7 treated with implant retention, 6 treated with a two-staged revision), 4 for instability and one for acetabular aseptic loosening. There were no aseptic failures of the stem. This novel modern monoblock TFT stem provided reliable femoral fixation and has increasingly supplanted the use of modular TFT stems for complex primary and revision surgery in our institution

Aims. Femoral revision component subsidence has been identified as predicting early failure in revision hip surgery. This comparative cohort study assessed the potential risk factors of subsidence in two commonly used femoral implant designs. Methods. A comparative cohort study was undertaken, analyzing a consecutive series of patients following revision total hip arthroplasties using either a tapered-modular (TM) fluted titanium or a porous-coated cylindrical modular (PCM) titanium femoral component, between April 2006 and May 2018. Clinical and radiological assessment was compared for both treatment cohorts. Risk factors for subsidence were assessed and compared. Results. In total, 65 TM and 35 PCM cases were included. At mean follow-up of seven years (1 to 13), subsidence was noted in both cohorts during the initial three months postoperatively (p < 0.001) then implants stabilized. Subsidence noted in 58.7% (38/65 cases) of the TM cohort (mean 2.3 mm, SD 3.5 mm) compared to 48.8% (17/35) of PCM cohort (mean 1.9 mm, SD 2.6 mm; p = 0.344). Subsidence of PCM cohort were significantly associated with extended trochanteric osteotomy (ETO) (p < 0.041). Although the ETO was used less frequently in PCM stem cohort (7/35), subsidence was noted in 85% (6/7) of them. Significant improvement of the final mean Oxford Hip Score (OHS) was reported in both treatment groups (p < 0.001). Conclusion. Both modular TM and PCM revision femoral components subsided within the femur. TM implants subsided more frequently than PCM components if the femur was intact but with no difference in clinical outcomes. However, if an ETO is performed then a PCM component will subside significantly more and suggests the use of a TM implant may be advisable. Cite this article: Bone Joint J 2020;102-B(6):709–715

The goals of revision total hip on the femoral side are to achieve long term stable fixation, improve quality of life and minimise complications such as intra-operative fracture or dislocation. Ideally these stems will preserve or restore bone stock. Modular titanium stems were first introduced in North America around 2000. They gained popularity as an option for treating Paprosky 3B and 4 defects. Several studies at our institution have compared modular titanium stems with monoblock cobalt chromium stems. The main outcomes of interest were quality of life. We also looked at complications such as intra-operative fracture and post-operative dislocation. We also compared these 2 stems with respect to restoration or preservation of bone stock. In 2 studies we showed that modular titanium stems gave superior functional outcomes as well as decreased complications compared to a match cohort of monoblock cobalt chromium stems. As mentioned, one of the initial reasons for introduction of these stems was to address larger femoral defects where failure rates with monoblock cobalt chromium stems were unacceptably high. We followed a group of 65 patients at 5–10 years post revision with a modular fluted titanium stem. Excellent fixation was obtained with no cases of aseptic loosening. However, there were 5 cases of fracture of the modular junction. Due to concerns of fracture of the modular junction, more recently, at our institution, we have switched to almost 100% monoblock fluted titanium stems. We recently reviewed our first 100 cases of femoral revision with a monoblock stem. Excellent fixation was achieved with no cases of aseptic loosening. Quality of life outcomes were similar to our previous reported series on modular tapered titanium stems. Both monoblock and modular fluted titanium stems can give excellent fixation and excellent functional outcomes. This leaves a choice for the surgeon. For the low volume revision surgeon modular tapered stems are probably the right choice. Higher volume surgeons or surgeons very comfortable with performing femoral revision may want to consider monoblock stems. If one is making the switch it would be easiest to start with a simple case. Such a case would be one that can be done with a endofemoral approach. In this approach the greater trochanter is available as the key landmark for reaming. After the surgeon is comfortable with this stem more complex cases can easily be handled with the monoblock stem. In summary, both modular and monoblock titanium stems are excellent options for femoral revision. As one becomes more familiar with the monoblock stem it can easily become your workhorse for femoral revision. At our institution we introduced a monoblock titanium stem in 2011. It started out at 50% of cases and now it is virtually used in almost 100% of revision cases

Introduction. As the proximal femoral bone is generally compromised in failed total hip arthroplasty, achievement of solid fixation with a new component can be technically demanding. Clinical studies have demonstrated good medium-term results after revision total hip arthroplasty using modular fluted and tapered distal fixation stems, but, to our knowledge, long-term outcomes have been rarely reported in the literature. The purpose of this study was to report the minimum ten-year results of revision total hip arthroplasty using a modular fluted and tapered distal fixation stem. Materials & Methods. We analyzed 40 revision THAs performed in using a modular fluted and tapered distal fixation stem (Fig. 1) between December 1998 and February 2004. There were 11 men (12 hips) and 28 women (28 hips) with a mean age of 59 years (range, 38 to 79 years) at the time of revision THA. According to the Paprosky classification of femoral defects, 5 were Type II, 24 were Type IIIA, and 11 were Type IIIB. An extended trochanteric osteotomy was carried out in 21 (52%) of the 40 hips. Patients were followed for a mean of 11.7 years (range, 10 to 15 years). Results. The mean Harris hip score improved from 41 points preoperatively to 85 points at the time of the latest follow-up. A total of 4 hips required additional surgery. One hip had two-stage reconstruction due to deep infection, one had liner and head exchange for ceramic head fracture, one had isolated cup re-revision for aseptic loosening, and one had constrained component revision for recurrent dislocation. No repeat revision was performed due to aseptic loosening of femoral stem. There was no stem fracture at the modular junction. Kaplan-Meier survivorship with an end point of stem re-revision for any reason was 98.1% at 11.7 years (Fig. 2), and, for aseptic stem loosening, the best-case scenario was 100% and the worst-case scenario was 91.9% at 11.7 years (Fig. 3). Conclusions. A modular fluted and tapered distal fixation stem continued to provide a reliable fixation at a minimum ten years after revision THA and can therefore be recommended as a promising option for challenging revision situations with femoral bone defects

Periprosthetic fractures (PPF) of the femur following total hip arthroplasty represent a significant complication with a rising incidence. The commonest subtype is Vancouver B2 type, for which revision to a long uncemented tapered fluted stem is a widely accepted management. In this study we compare this procedure to the less commonly performed cement-in-cement revision. All patients undergoing surgical intervention for a Vancouver B2 femoral PPF in a cemented stem from 2008 – 2018 were identified. We collated patient age, gender, ASA score, BMI, operative time, blood transfusion requirement, change in haemoglobin (Hb) level, length of hospital stay and last Oxford Hip Score (OHS). Radiographic analysis was performed to assess time to fracture union and leg length discrepancy. Complications and survivorship of implant and patients were recorded. 43 uncemented and 29 cement-in-cement revisions were identified. There was no difference in patient demographics between groups. A significantly shorter operative time was found in the cement-in-cement group, but there was no difference in transfusion requirement, Hb change, or length of hospital stay. OHS was comparable between groups. A non-significant increase in overall complication rates was found in the revision uncemented group, with a significantly higher dislocation rate. Time of union was comparable and there were no non-unions in the cement-in-cement group. A greater degree of stem subsidence was found in the uncemented group. There was no difference in any revision surgery required in either group. Three patients in the uncemented group died in the perioperative period, compared to none in the cement-in-cement group. With appropriate patient selection, both cement-in-cement and long uncemented tapered stem revision represent appropriate treatment options for Vancouver B2 fractures

The goals of revision total hip on the femoral side are to achieve long term stable fixation, improve quality of life and minimise complications such as intra-operative fracture or dislocation. Ideally these stems will preserve or restore bone stock. Modular titanium stems were first introduced in North America around 2000. They gained popularity as an option for treating Paprosky 3B and 4 defects. Several studies at our institution have compared the modular titanium stems with monoblock cobalt chromium stems. The main outcomes of interest were quality of life. We also looked at complications such as intra-operative fracture and post-operative dislocation. We also compared these 2 stems with respect to restoration or preservation of bone stock. In 2 studies we showed that modular titanium stems gave superior functional outcomes as well as decreased complications compared to a match cohort of monoblock cobalt chromium stems. As mentioned one of the initial reasons for introduction of these stems was to address larger femoral defects where failure rates with monoblock cobalt chromium stems were unacceptably high. We followed a group of 65 patients at 5–10 years post-revision with a modular fluted titanium stem. Excellent fixation was obtained with no cases of aseptic loosening. However, there were 5 cases of fracture of the modular junction. Due to concerns of fracture of the modular junction more recently at our institution we have switched to almost 100% monoblock fluted titanium stems. We recently reviewed our first 100 cases of femoral revision with monoblock stem. Excellent fixation was achieved with no cases of aseptic loosening. Quality of life outcomes were similar to our previous reported series on modular tapered titanium stems. Both monoblock and modular fluted titanium stems can give excellent fixation and excellent functional outcomes. This leaves a choice for the surgeon. For the low volume revision surgeon modular tapered stems are probably the right choice. Higher volume surgeons or surgeons very comfortable with performing femoral revision may want to consider monoblock stems. If one is making the switch it would be easiest to start with a simple case. Such a case would be one that can be done with an endofemoral approach. In this the greater trochanter is available as the key landmark for reaming. After the surgeon is comfortable with this stem more complex cases can easily be handled with the monoblock stem. In summary, both modular and monoblock titanium stems are excellent options for femoral revision. As one becomes more familiar with the monoblock stem it can easily become your workhorse for femoral revision. At our institution we introduced a monoblock titanium stem in 2011. It started out at 50% of cases and now it is virtually used in almost 100% of revision cases

Introduction. Self tapping bone screw has been widely used in the fixation of Arthroplasty implants and bone graft. But the unwanted screw or driver breakage can be a direct result of excessive driving torque due to the thread cutting resistance. Previous studies showed that bone drill bit cutting rake angle was a critical factor and was inversely related to the bone cutting efficiency. 1, 2, 3, 4. (Figure 1) However to date there was no data for how the rake angle could influence the performance of self tapping bone screw. The purpose of this study was to investigate the torque generated by the self tapping cortical screw in simulated bone insertion as a function of the screw tip cutting flute rake angle. Methods. Two 5 mm thick BM5166 polyurethane block were stacked together and drilled through with 2.5mm diameter holes. Five 30mm long 3.5 mm diameter Ti6AL4V alloy self tapping cortical screws with 0°rake angle cutting flutes (Figure 2) were inserted in the holes and driven by the spanner attached to the test machine (Z5.0TN/TC-A-10) with a displacement control of 3 revolutions/min and 30N constant axial loading. The screws were driven into the stacked polyurethane block for 8mm depth. The maximum driving torque was recorded. Procedure was repeated for five same screws but with 7° rake angle cutting flutes. (Figure 2) The driving torqueses were compared. Student t test was performed with confidence level of 95% was assumed. Results. The average insertion driving torque for the screw with 7° rake angle was 30% less torque required than that of the screw with 0° rake angle. (P=5.3E–06<0.05) (Table 1). Conclusion and discussion. Screw failure during the insertion would be a nightmare. A slight positive rake angle significantly decreases the torque resistance. This design feature can significantly increase the safety margin of the self tapping screw implants and screw driving instruments. The likely mechanism would be the positive rake angle generated a more efficient bone cutting instead of pushing. More study on driving torque as a function of wider rake angle change is warranted. For figures and tables, please contact authors directly

250 words max Long polished cemented femoral stems, such as the Exeter Hip Revision stem, are one option available to the revision hip arthroplasty surgeon. When proximal bone stock is compromised, distal fixation is often relied upon for stability of the femoral component. In such circumstances, torsional forces can result in debonding and loosening. This study compared the torsional behaviour of a cemented polished and featureless (plain) stem with cemented, polished stems featuring fins or flutes. Nine torsional tests were carried out on each of these three different stem designs. The finned stem construct was significantly stiffer than the fluted stem (mean 24.5 Nm/deg v 17.5 Nm/deg). The plain stem mean stiffness was less than the featured stems (13 Nm/deg), but wide variability lead to no statistically significant difference. The maximum torque of the finned (30.5 Nm) and fluted stems (29 Nm) was significantly higher than the plain stem (10.5 Nm); with no significance to the difference between the finned and fluted stems. Distal stem features may provide a more reliable and greater resistance to torque in polished, cemented revision hip stems. Finned stem features may also increase the stiffness of the construct. Consideration should thus be given to the incorporation of distal stem features in the design of revision hip stems

Tapered fluted titanium stems are increasingly used for femoral revision arthroplasty. They are available in modular and non-modular forms. Modularity has advantages when the bone loss is severe, the proximal femur is mis shapen or the surgeon is unfamiliar with the implant, but it introduces the risk of fracture of the stem at the junction between it and the proximal body segment. For that reason, and while awaiting intermediate-term results of more recently introduced designs of this junction, non-modularity has attracted attention, at least for straightforward revision cases. . We review the risks and causes of fracture of tapered titanium modular revision stems and present an argument in favour of the more selective use of modular designs. Cite this article: Bone Joint J 2016;98-B(1 Suppl A):50–3

The goals of revision total hip on the femoral side are to achieve long term stable fixation, improve quality of life and minimise complications such as intra-operative fracture or dislocation. Ideally these stems will preserve or restore bone stock. Modular titanium stems were first introduced in North America around 2000. They gained popularity as an option for treating Paprosky 3B and 4 defects. Several studies at our institution have compared the modular titanium stems with monoblock cobalt chromium stems. The main outcomes of interest were quality of life. We also looked at complications such as intra-operative fracture and post-operative dislocation. We also compared these 2 stems with respect to restoration or preservation of bone stock. In two studies we showed that modular titanium stems gave superior functional outcomes as well as decreased complications compared to a matched cohort of monoblock cobalt chromium stems. As mentioned one of the initial reasons for introduction of these stems was to address larger femoral defects where failure rates with monoblock cobalt chromium stems were unacceptably high. We followed a group of 65 patients at 5–10 years post-revision with a modular fluted titanium stem. Excellent fixation was obtained with no cases of aseptic loosening. However, there were 5 cases of fracture of the modular junction. Due to concerns of fracture of the modular junction more recently, at our institution we have switched to almost 100% monoblock fluted titanium stems. We recently reviewed our first 100 cases of femoral revision with monoblock stem. Excellent fixation was achieved with no cases of aseptic loosening. Quality of life outcomes were similar to our previous reported series on modular tapered titanium stems. Both monoblock and modular fluted titanium stems can give excellent fixation and excellent functional outcomes. This leaves a choice for the surgeon. For the low volume revision surgeon modular tapered stems are probably the right choice. Higher volume surgeons or surgeons very comfortable with performing femoral revision may want to consider monoblock stems. If one is making the switch it would be easiest to start with a simple case. Such a case would be one that can be done through an endofemoral approach. In this the greater trochanter is available as the key landmark for reaming. After the surgeon is comfortable with this system more complex cases can easily be handled with the monoblock stem. In summary, both modular and monoblock titanium stems are excellent options for femoral revision. As one becomes more familiar with the monoblock stem it can easily become your workhorse for femoral revision. At our institution, we introduced a monoblock titanium stem in 2011. It started out at 50% of cases and now it is virtually used in almost 100% of revision cases

Summary Statement. Proximal femoral bony deficits present a surgical and biomechanical challenge to implant longevity in revision hip arthroplasty. This work finds comparable primary stability when a distally fixing tapered fluted stem was compared with a conical design in cadaveric tests. Introduction. Proximal bony deficits complicate revision hip surgery and compromise implant survival. Longer distally fixing stems which bypass such defects are therefore required to achieve stability compatible with bony ingrowth and implant longevity. Aims. It is hypothesised that a tapered stem will provide superior rotational stability to a conical design. This work therefore aims to compare the primary stability and biomechanical properties of a new design of tapered fluted modular femoral stem (Redapt®, Smith & Nephew) with that of a conical fluted stem (Restoration®, Stryker). Materials & Methods. 7 Pairs of cadaveric femora were obtained according to strict inclusion/exclusion criteria. Each underwent dual energy x-ray absorptiometry and calibration plain-film radiographs were taken. Digital templating was performed using TraumaCad (Voyant Health, Brainlab) to determine implant sizing. Both stems are fluted, modular and manufactured from titanium. The control stem (Restoration) featured a straight conical design and the investigation stem (Redapt) a straight tapered design. Implantation was performed by a revision arthroplasty surgeon familiar with both systems. Proximal bone deficiency was reproduced using an extended trochanteric osteotomy with removal of metaphyseal bone before reattaching the osteotomy. Primary stability in the axial, sagittal and coronal planes was assessed using micromotion transducers (HBM, Darmstadt, Germany) and also by Radiostereometric Analysis (RSA). RSA employs simultaneous biplanar radiographs to measure relative movement. Two 1mm tantalum beads were mounted on the prosthesis with the centre of the femoral head taken as the third reference point. Beads were placed proximally in the surrounding bone as rigid body markers. Each bone was potted according to the ISO standard for fatigue testing and cyclically loaded at 1Hz for at least 3 increments (750–350N, 1000–350N, 1500–350N) for 1000 cycles. RSA radiographs were taken at baseline and on completion of each cycle. A strain analysis was concurrently performed using a PhotoStress® (Vishay Precision Group, Raleigh, USA) photoelastic coating on the medial femoral cortex. Each bone was loaded intact and then with the prosthesis in-situ at 500N increments until strain fringes were identified. Once testing was completed, the stems were sectioned at the femoral isthmus and data is presented on the cross-sectional fit and fill observed. Results. Both stem designs showed comparable primary stability with all stems achieving clinically acceptable micromotion (<150 μm) when loaded at body weight. A larger proportion of the control stems remained stable as loading increased to x2-3 body weight. Transducer-recorded migration appeared greatest in the axial plane (y axis) with negligible distal movement in the coronal or sagittal planes. Point motion analysis (RSA) indicated most movement to be in the coronal plane (x-axis) whereas segment motion analysis showed rotation about the long axis of the prosthesis to be largest. Photoelastic strain patterns were transferred more distally in both designs, however substantial stress shielding was also observed. Discussion/Conclusion. Both designs achieved adequate distal fixation and primary stability under representative clinical loading conditions. This work supports the continued use of this novel stem design for revision surgery in the presence of extensive proximal bone loss

Introduction. Undersizing of an uncemented femoral stem is a post-operative description of a radiograph with unclear clinical importance. It may not always translate into a suboptimal clinical outcome. Aim. To describe a novel classification system of undersizing in a fully hydroxyapatite coated femoral implant, assess if it could be reliably reported between observers, and describe a simple way to assess the degree of undersizing on an AP radiograph. Methods. A retrospective review of 1000 consecutive total hip arthroplasties was conducted. Two investigators reviewed post-operative radiographs independently for stem undersizing. The data was tested for inter and intra-observer agreement using the Kappa method. Results. Undersizing was classified as:. Varus - Stem in contact proximally with medial calcar, and distally with lateral cortex. Valgus - Stem in contact proximally with lateral cortex, and distally with medial cortex. Uniform - Continuous margin around the stem of at least one-half tip width of the stem throughout. Champagne flute - Distal stem fills the narrow diaphysis with insufficient bony contact at the wide metaphysis. If varus or valgus undersizing was present we described the formation of two triangles of excess cancellous space around the implant, each having overlapping apices signifying undersizing by at least two sizes. 32% of the stems were undersized with Kappa demonstrating very good (89%) to good (86%) inter and intra observer agreement respectively. 50% of undersized stems were uniformly undersized, 36% were varus, 6% valgus, and 8% were in a champagne fluted shaped femur. A higher percentage of the lateralised (KLA) stems were undersized compared to other neck configurations (40%). 54% of these were varus undersized and this increased the offset up to 2cm. Conclusion. We describe a classification system for undersizing in hip arthroplasty. KLA stems have an increased tendency to be undersized in varus, thereby increasing the overall offset

Introduction: The use of self-tapping screws has become increasingly popular since it allows for a rapid screw placement avoiding the tapping step during ORIF of fractures.. While sharing the same basic principle of cutting flutes and partial threads at the tip, at least four types of screw design is currently available, varying in the number and shape of cutting flutes. The purpose of this biomechanical study was to research for any significant difference between the various self-tapping screws. Material and Methods: Three different designs of 4.5-mm self-tapping screws and one standard 4.5 screw serving as control were compared for pull-out strength after insertion into an adult human non-embalmed cadaveric humeri. All specimens were machined to a 5 mm uniform cortical thickness. Four equidistant 3.2 mm holes were drilled into each specimen by an MTS mounted drill. All screws were inserted randomly in one of the four positions using a hand screwdriver. The cortical bone specimen was secured between two metal plates to the base of a MTS machine while a uniaxial tensile force was applied to the jig for screw removal at a rate of 0.833 mm/sec until holding power had decreased to 25 % of the maximum. Load displacement curves were recorded. Resulting data was analyzed using paired student-t tests. P values of less then 0.05 were considered statistically significant. Results: The mean load-to-failure was 97.4167N (S.D. 13.29924) for the Synthes control screw, 69.2333N (S.D. 4.48360) for the Synthes self-tapping screw, 67.15 (S.D. 11.23864) for the Stryker self-tapping screw, and 55.0667 (S.D. 8.59271) for the ODI self-tapping screw. A significant difference was found between the mean pull-out strength of the Synthes control screw when compared to each of the three self-tapping screws (Pairs 1–3, P < 0.05). Furthermore, the mean pull-out strength of the ODI self-tapping screw was found to be significantly less than Stryker self-tapping screw (Pair 6, P < 0.05). There was no significant difference between Synthes self-tapping screws and Stryker self-tapping screws (Pair 5, P < 0.05). Discussion and conclusion: Self tapping screws with three short cutting flutes performed better than those with two long cutting flutes. Despite of the different designs and length of the cutting flutes in self-tapping screws, they all have less pull out strength than regular screws

Revision total hip arthroplasty (THA) is projected to increase by 137% from the years 2005 to 2030. Reconstruction of the femur with massive bone loss can be a formidable undertaking. The goals of revision surgery are to create a stable construct, preserve bone and soft tissues, augment deficient host bone, improve function, provide a foundation for future surgery, and create a biomechanically restored hip. Options for treatment of the compromised femur include: resection arthroplasty, allograft prosthetic composite (APC), proximal femoral replacement, cementless fixation with a modular tapered fluted stem, and impaction grafting. The purpose of this article is to review the treatment options along with their associated outcomes in the more severe femoral defects (Paprosky types IIIb and IV) in revision THA.

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

When fracture of an extensively porous-coated femoral component occurs, its removal at revision total hip arthroplasty (THA) may require a femoral osteotomy and the use of a trephine. The remaining cortical bone after using the trephine may develop thermally induced necrosis. A retrospective review identified 11 fractured, well-fixed, uncemented, extensively porous-coated femoral components requiring removal using a trephine with a minimum of two years of follow-up. . The mean time to failure was 4.6 years (1.7 to 9.1, standard deviation (. sd. ) 2.3). These were revised using a larger extensively porous coated component, fluted tapered modular component, a proximally coated modular component, or a proximal femoral replacement. The mean clinical follow-up after revision THA was 4.9 years (2 to 22, . sd. 3.1). The mean diameter of the femoral component increased from 12.7 mm (. sd. 1.9) to 16.2 mm (. sd. 3.4; p >  0.001). Two revision components had radiographic evidence of subsidence that remained radiographically stable at final follow-up. The most common post-operative complication was instability affecting six patients (54.5%) on at least one occasion. . A total of four patients (36.4%) required further revision: three for instability and one for fracture of the revision component. There was no statistically significant difference in the mean Harris hip score before implant fracture (82.4; . sd. 18.3) and after trephine removal and revision THA (81.2; . sd. 14.8, p = 0.918). . These findings suggest that removal of a fractured, well-fixed, uncemented, extensively porous-coated femoral component using a trephine does not compromise subsequent fixation at revision THA and the patient’s pre-operative level of function can be restored. However, the loss of proximal bone stock before revision may be associated with a high rate of dislocation post-operatively. Cite this article: Bone Joint J 2015;97-B:1192–6

Cementless stem fixation is a widely used method of stem revision in North America and elsewhere in the world. There is abundant literature in its support. Most of the reports from 1985 to 2005 related to proximally or extensively porocoated designs, the former falling into disfavor with time because of unpredictable outcomes. With few exceptions (e.g. S-ROM) the modularity of these designs was limited to the head/neck junction. But this generation of designs was associated with some issues such as insertional fractures, limited control of anteversion (and risk of dislocation), limited applicability in the setting of severe bone loss (Paprosky Type 4 osteolysis or Vancouver Type B3 periprosthetic fracture), as well as ongoing concern relating to severe proximal stress shielding. In the past decade we have seen the mounting use of a new design concept: tapered fluted titanium stems (TFTS), which incorporate the advantages of titanium (for less flexural rigidity), conical taper (for vertical taper-lock stability), longitudinal ribs or flutes (for rotational stability), and surface preparation which attracts bone ongrowth for long term fixation. Four consecutive reports from our center have documented the superiority of the TFTS in our hands, with encouraging outcomes even when dealing with severe bone loss or periprosthetic fractures. There is an increasing body of other literature which reports a similar experience. Furthermore, with increasing experience and confidence in this design concept, we now use a monoblock or non-modular design in the majority of cases in which a TFTS is indicated. This circumvents the potential drawbacks of stem modularity, including taper corrosion and taper junction fracture. Our recent report of this concept in 104 cases with a 2-year minimum follow-up supports the use of this concept in many if not most stem revisions. The question remains as to which should be favored? Because of equipoise in the outcomes of the two fundamental stem designs, at least in our hands, clearly the surgeon needs to ask other, more practical questions:. Am I familiar enough with the TFTS technique so as to bypass the potential versatility of the modular stem for the simplicity and potential cost savings of the non-modular?. Is this a case in which modularity will offer me distinct advantages (periprosthetic fracture, and severe bone loss as examples). Should I introduce the nonmodular TFTS to my practice, choosing straightforward cases first; ones in which I would comfortably and with confidence use an extensively porocoated stem?

Introduction. Revision hip arthroplasty is a technically challenging operation as proximal bony deficits preclude the use of standard implants. Longer distally fixing stems are therefore required to achieve primary stability. Aims. This work aims to compare the primary stability and biomechanical properties of a new design of tapered fluted modular femoral stem (Redapt®, Smith & Nephew) to that of a conical fluted stem (Restoration®, Stryker). It is hypothesized that the taper will provide improved rotational stability under cyclical loading. Materials & Methods. 7 Pairs of cadaveric femora were obtained according to strict inclusion/exclusion criteria. Each underwent dual energy x-ray absorptiometry and calibration plain-film radiographs were taken. Digital templating was performed using TraumaCad (Voyant Health, Brainlab) to determine implant sizing. Both stems are fluted, modular and manufactured from titanium (figure 1). The control stem (Restoration) featured a straight conical design and the investigation stem (Redapt) a straight tapered design. Implantation was performed by a revision arthroplasty surgeon familiar with both systems. Proximal bone deficiency was reproduced using an extended trochanteric osteotomy with removal of metaphyseal bone before reattaching the osteotomy. Primary stability in the axial, sagittal and coronal planes was assessed using micromotion transducers (HBM, Darmstadt, Germany) (figure 2a) and also by Radiostereometric Analysis (RSA). RSA employs simultaneous biplanar radiographs to measure relative movement. Two 1 mm tantalum beads were mounted on the prosthesis with the centre of the femoral head taken as the third reference point. Beads were placed proximally in the surrounding bone as rigid body markers. Each bone was potted according to the ISO standard for fatigue testing and cyclically loaded at 1 Hz for at least 3 increments (750–350N, 1000–350N, 1500–350N) for 1000 cycles. RSA radiographs were taken at baseline and on completion of each cycle. A strain analysis was concurrently performed using a PhotoStress ® (Vishay Precision Group, Raleigh, USA) photoelastic coating on the medial femoral cortex. Each bone was loaded intact and then with the prosthesis in-situ at 500N increments until strain fringes were identified. Once testing was completed, the stems were sectioned at the femoral isthmus and data is presented on the cross-sectional fit and fill observed. Results. Both stem designs showed comparable primary stability with all stems achieving clinically acceptable micromotion (<150 μm) when loaded at body weight. A larger proportion of the control stems remained stable as loading increased to x2–3 body weight. Transducer-recorded migration appeared greatest in the axial plane (y axis) (figure 2b) with negligible distal movement in the coronal or sagittal planes. Point motion analysis (RSA) indicated most movement to be in the coronal plane (x-axis) (figure 2c) whereas segment motion analysis showed rotation about the long axis of the prosthesis to be largest. Photoelastic strain patterns were transferred more distally in both designs, however substantial stress shielding was also observed (figure 3). Discussion/Conclusion. Both designs achieved adequate distal fixation and primary stability under representative clinical loading conditions. This work supports the continued use of this novel stem design for revision surgery in the presence of extensive proximal bone loss

Purpose:. Glenoid loosening persists as a common cause of anatomic total shoulder arthroplasty (TSA) failure. Considering radiographic evidence of loosening as an endpoint, TSA has a reported survivorship of only 51.5% at 10 years. Component loosening may be related to cementation and it is postulated that poor cement penetration and heat-induced necrosis may partially be responsible. There is a growing interest among surgeons to minimize or abandon cement fixation and rely on biologic fixation to the polyethylene for long-term fixation. De Wilde et al. reported promising early clinical and radiographic results using a pegged, all-polyethylene ingrowth glenoid design implanted without cement. The goal of this study was to compare glenoid micromotion in an all-polyethylene, centrally fluted pegged glenoid using 3 cement fixation techniques. Materials and Methods:. Glenoid components (Anchor Peg Glenoid, Depuy Orthopaedics, Warsaw, IN, USA) (Figure 1) were implanted in polyurethane foam testing blocks with 3 different fixation methods (n = 5 per group). Group I glenoids were implanted with interference fit fixation with no added cement. Group II was implanted with a hybrid fixation, where only the peripheral pegs were cemented. Group III glenoids were fully cemented for implantation. Glenoid loosening was characterized according to ASTM Standard F-2028. The glenoid component and a 44 mm humeral head were mounted to a materials testing frame (858 Mini Bionix II, MTS Crop., Eden Prairie, MN, USA) with a 750N applied joint compressive force (Figure 1). A humeral head subluxation displacement of ± 0.5 mm was experimentally calculated as a value that simulates glenoid rim loading that may occur at higher load activities. For characterization of glenoid loosening, the humeral head was cycled 50,000 times along the superior-inferior glenoid axis, simulating approximately 5 years of device service. Glenoid distraction, compression, and superior-inferior glenoid migration were recorded with two differential variable reluctance transducers fixed to the glenoid prosthesis. Results:. All glenoid components completed the 50,000 cycles of humeral head translation successfully. With respect to glenoid distraction (Figure 2), interference fit fixation had significantly greater distraction compared to both hybrid and fully cemented fixation (p < 0.001). Hybrid fixation also displayed significantly higher distraction compared to fully cemented fixation (p < 0.001). In terms of glenoid compression (Figure 2), hybrid cementation had significantly greater compression compared to both interference-fit and fully cemented fixation (p < 0.001). Discussion:. This is the first biomechanics study comparing glenoid micromotion of a centrally fluted, pegged component using 3 different fixation techniques. Of all fixation methods, the fully cemented components displayed the least amount of motion in all parameters. Hybrid fixation exhibited lower distraction, higher compression, and comparable translation compared to interference-fit fixation. Results may indicate the differences in early motion and suggest little to no advantage of peripheral peg cementation over no cement with respect to initial fixation. Future studies are warranted to further evaluate interference-fit fixation as a viable option for implantation of a central fluted, all-polyethylene glenoid component

Purpose. The purpose of this study was to evaluate the results of modular revision stems, uncemented fluted, tapered to treat periprosthetic femoral (PFF) fracture; we specifically evaluated fracture union, implant stability, patient outcomes, and complications to compare the differences between cemented and cementless primary stem. Materials and Methods. We retrospectively reviewed 56 cases of unstable periporsthetic femoral fracture (forty B2 and sixteen B3) treated with the uncemented fluted and tapered modular distal fixation stem with or with or without autogenous bone graft. Clinical outcomes were assessed with Harris Hip Score and WOMAC score. Radiologic evaluations were conducted using Beals and Tower's criteria. Any complication during the follow-up period was recorded. Results. The average follow-up period was 52.1±32.7 months. The average Harris Hip Score was 72.4±19.1. All fractures were united, and a good consolidation was achieved in 47 cases. There was femoral stem subsidence in 3 cases less than 10 mm without an evidence of loosening both radiologically and clinically. The radiologic results using Beals and Towers’ criteria were excellent in 36 hips, good in 10 hips and poor in 10 hips. Radiologic bone union took longer time and statistically significant stem subsidence was observed in cemented primary stem compared to cementless primary stem (Fig1,2). At each follow-up examination the clinical score was significantly higher in patients with cementless primary stem. Conclusion. Our results support the view that cement primary stem has less favorable result in terms of revision arthroplasty for periprosthetic femoral fractures

Aim. To assess the survivorship of a tapered fluted Titanium monoblock stem in conjunction with subtrochanteric shortening for patients with High Dislocation performed at 2 centres. Methods. This was a retrospective study of 84 hips in 52 patients between two centres. All patients had a high dislocation. Thirty five patients had bilateral dysplasia. All patients had total hip arthroplasty with a subtrochanteric shortening osteotomy. The acetabular component was placed at the level of the anatomic hip centre. The femoral component was the “Wagner Cone prosthesis” which is a monoblock Titnium Alloy stem, tapered and fluted. The acetabular component varied. All patients had a follow up examination with a Harris Hip Score and a plain radiograph. The radiographs were assessed for osteotomy complications, change in stem position, evidence of loosening, heterotopic ossification & stress shielding if any. Notes were reviewed for complications. Results. The mean age at operation was 55 yrs (range 20–83). The mean follow up was 9 years (range3–20). Eight patients were lost to follow up (16%). All the rest of the femoral components survived that were available for follow up −84% (worst case scenario). Six patients (7.8%) had an early complication that needed a reoperation. The Mean Harris Hip Score (HHS) improved from 42 points to 88 points. Conclusion. The success rate of patients undergoing Cementless Arthroplasty using the Wagner cone stem in conjunction with a subtrochanteric shortening osteotomy is very high. The complication rate is however larger than in the normal population

Introduction. Surgical drill-bits are used in a raft of procedures, from trauma, joint reconstruction to Arthroplasty. Drilling of bone is associated with the conversion of mechanical work energy into shear failure of bone and heat generation, causing a transient rise in temperature of hard and soft tissues. Thermal insults above 47°C sustained for one minute or more may cause osteonecrosis, reduced osteogenic potential, compromise fixation and influence tolerances with cutting blocks. Drill design parameters and operational variables have marked effects on cutting performance and heat generation during drilling. Dulling and wear of the cutting surfaces sustained through repeated usage can significantly reduce drill bit performance. Deterioration of cutting performance substantially increases the axial thrust force required to propel the cutting face through bone, compromising surgeon control during drilling and increasing the likelihood of uncontrolled plunging, cortical breakthrough and improper placement of holes as well as other jigs. Methods. The drilling accuracy and skiving of 2.8 mm 3-fluted SurgiBit (Orthopedic Innovation (OI), Sydney, Australia) (Figure 1) was compared with a standard 2-fluted drill (Synthes) at 15, 30 and 45 degrees using a 4. th. generation Sawbone as well as bovine cortical bone. A surgical handpiece was mounted in a servo-hydraulic testing machine and the motion of the drill-bit confined to 2 degrees of freedom. The lateral force and skiving distance was measured (n=6 per drill per angle per testing medium). A new drill was used for each test. Wear performance over multiple drilling episodes (1, 10 and 100) was performed in bovine cortical bone. The surface characteristics of the cutting faces of the drills were assessed optically at 10x magnification and at higher magnifications (50, 100 and 500x) using an environmental electron microscope. Results. The OI 3 fluted design outperformed the 2-fluted design in terms of lateral forces beyond 15 degrees (P<0.05). Skiving occurred with the 2-fluted design at all angles while this did not occur with the OI 3-fluted design. The stiffness (lateral force/skiving distance) for the OI 3-fluted design was more than twice that of the 2-fluted design. Wear performance of the OI 3-fluted design was superior to the 2-fluted design based on optical and SEM analysis. Discussion and Conclusions. Both 2 and 3-fluted surgical drill-bits are in clinical use. The OI 3 fluted drill is unique in its negatively-raked pyramidal tip geometry which induces a ductility change in the cutting medium, thereby improving cutting efficiency for the ensuing trio of positively raked cutting surfaces. This reduces wear and decreases heat generation compared to their diameter-matched 2 and 3-fluted counterparts. Three fluted drills are inherently more efficient due to the inclusion of an additional cutting face, which can potentially remove 50% more material per rotation. The acute tip angle and geometry in the 3-fluted OI design also improves accuracy and targeting ability for the surgeon. Mechanically, 3-fluted drills have higher bending resistance, even during operation, which decreases the likelihood of intra-operative breakage. The engineering advantages of the OI 3-fluted design are beginning to be realized at the clinical level

Introduction and Aims: The use of porous coated femoral stems in revision hip arthroplasty has been associated with a high rate of complications including femoral fracture, femoral perforation and eccentric reaming. The purpose is to determine if using a distally slotted-fluted femoral stem is associated with lower incidence of the above three intra-operative complications. Method: The intra-operative complications of 175 cementless revision total hip arthropasties (THA) using a distally slotted-fluted femoral stem were reviewed. Three categories of complications were recorded: femoral fracture, femoral perforation and eccentric reaming. Radiographic evaluation was based on standard antero-posterior and lateral views of the hip joint performed in the intra-operative or immediate post-operative period. Statistical analysis for factors associated with complications was performed using the chi-square test. Results: Intra-operative complications occurred in 16 patients (9.1%). There was no statistically significant association between complication rate and type of surgical approach, stem length, stem diameter, or host bone quality. The complication rate was significantly lower than the 44% total complication rate previously reported utilising a long, solid, extensively coated revision stem without a slot or flute (p< .01). These results are consistent with laboratory testing, which revealed significantly lower bone strains at the isthmus when inserting a long cementless revision stem with a slot and flute compared to a solid fully coated stem of identical geometry. Conclusion: The use of a distally slotted fluted porous coated femoral stem in revision hip arthroplasty results in a dramatically lower complication rate compared to rates previously reported for solid porous stems. These results strongly support the continued use of such a prosthesis for revision THA

Cementless femoral components have an excellent track record that includes efficient implantation and long-term survival, thus are the predominant stem utilised in North America. Femoral component stability and resistance to subsidence are critical for osseointegration and clinical success. Implant design, surgical technique, anatomic fit, and patient characteristics, such as bone quality, can all effect initial implant stability and resistance to subsidence. Variability in stem shape and in the anatomy of the proximal femoral metaphysis has been implicated in the failure of some stem designs. Biologic fixation obtained with osseointegration of cementless implants may improve implant longevity in young, active, and obese patients. Lack of intimate fit can lead to clinical complications such as subsidence, aseptic loosening, and peri-prosthetic fracture. Currently, there are several stem designs, all of which aim to achieve maximal femoral stability and minimal subsidence and include: Fit and Fill / Double Taper Proximally Porous Coated Stems; Parallel Sided Taper Wedge or “Blade” Stems; Wagner Style Conical Shape Splined Titanium Stems; Tapered Rectangular Cross-Section Zweymuller Stem; Fully-Porous Coated Stems; Modular Proximal Sleeve Fluted Stem; Anatomic Proximally Porous Coated Stems. The majority of patients with relatively straightforward anatomy can be treated with any of the aforementioned femoral implant types. However, more complicated femoral anatomy frequently requires a particular implant type to maximise stability and promote osseointegration. Stems with femoral deformity in the meta-diaphyseal region may require a shorter stem in order to avoid an osteotomy. Distorted femoral anatomy typically seen in childhood diseases, such as dysplasia, may require a modular proximal sleeve tapered fluted stem or Wagner style cone stem to impart optimal stem anteversion separate from the native femoral neck version. The most severe forms of dysplasia may require a shortening osteotomy and subsequent distal fixation and neck version flexibility, which can be addressed with a modular proximal sleeve fluted or fully porous coated stem. A stovepipe or osteoporotic femur may require a stem that engages more distally such as a conical splined tapered stem, a fully porous coated stem or even a cemented stem to achieve adequate stability. Finally, obese patients are a particular challenge and emerging data suggests that a morphologically based parallel-sided taper wedge stems may confer greater stability and resistance to subsidence in these patients. Ultimately, an appropriate selection algorithm will facilitate an appropriate match of the patient morphology with femoral implant geometry that facilitates stable fixation and osseointegration

Aims. To evaluate the hypothesis that failed osteosynthesis of periprosthetic Vancouver type B1 fractures can be treated successfully with stem revision using a transfemoral approach and a cementless, modular, tapered revision stem with reproducible rates of fracture healing, stability of the revision stem, and clinically good results. Patients and Methods. A total of 14 patients (11 women, three men) with a mean age of 72.4 years (65 to 90) undergoing revision hip arthroplasty after failed osteosynthesis of periprosthetic fractures of Vancouver type B1 were treated using a transfemoral approach to remove the well-fixed stem before insertion of a modular, fluted titanium stem which obtained distal fixation. These patients were clinically and radiologically followed up for a mean 52.2 months (24 to 144). Results. After a mean of 15.5 weeks (standard deviation (. sd. ) 5.7) all fractures had healed. No stems subsided and bony-ingrowth fixation had occurred according to the classification of Engh et al. The mean Harris Hip Score increased from a pre-operative score of 22.2 points (. sd. 9.7) to 81.5 points (. sd. 16.8) 24 months post-operatively. All hips had obtained an excellent result according to the classification of Beals and Tower. Conclusions. The technique described here for stem revision provides reproducibly good results in the treatment of failed osteosynthesis for Vancouver types B1 periprosthetic fractures of the hip. Cite this article: Bone Joint J 2017;99-B(4 Supple B):11–16

The femur begins to bow anteriorly at the 200 mm level, but may bow earlier in smaller people. If the stem to be used is less than 200 mm, a straight stem can be used. If the stem is longer than 200 mm, it will perforate the anterior femoral cortex. I know this because I did this on a few occasions more than 20 years ago. To use a long straight stem, there are two techniques. One can either do a diaphyseal osteotomy or one can do a Wagner split (extended trochanteric osteotomy). Both of these will put the knee in some degree of hyperextension, probably insignificant in the elderly, but it may be of significance in the young. In very young people, therefore, it may be preferable to use a bowed stem to avoid this degree of recurvatum. There are two different concepts of loading. Diaphyseal osteotomy implies a proximal loading has been sought. The Wagner split ignores the proximal femur and seeks conical fixation in the diaphysis. There will be very little bone-bone contact between what remains of the attached femur and the detached anterior cortex so that it is important to ensure that the blood supply to the anterior cortex remains intact, preferably by using Wagner's technique, using a quarter-inch osteotome inserted through the vastus to crack the medial cortex. Current modularity is of two types. Distal modularity was attempted many years ago and was never successful. Proximal modularity, as for example, the S-ROM stem, implies various sizes of sleeves fit onto the stem to get a proximal canal fill. In mid-stem modularity, the distal stem wedges into the cone. It has to be driven into where it jams and this can be somewhat unpredictable. For this reason, the solid Wagner stem has been replaced by the mid-stem modular. Once the distal femur is solidly embedded, the proximal body is then selected for height and version. The proximal body is unsupported in the mid-stem modular and initially, few fractures were noted at the taper junction. Cold rolling, shot peening and taper strengthening seem to have solved these problems. There are a variety of types of osteotomy, which can be used for different deformities. With a mid-stem modular system, generally, all that needs to be done is a Wagner-type split and fixation is sought in the mid-diaphysis by conical reaming. No matter what stem is used, distal stability is necessary. This is achieved by flutes, which engage the endosteal cortex. The flutes alone must have sufficient rotational stability to overcome the service loads on the hip of 22 Nm. I divide revision into three categories. In type one, the isthmus is intact, i.e. the bone below the lesser trochanter so that a primary stem can be used. In type two, the isthmus is damaged, i.e. the bone below the lesser trochanter, so a long revision stem is required. In a type three, there is more than 70 mm of missing proximal femur. The Wagner stem may be able to handle this on its own, but most other stems are better supported with a structural allograft cemented to the stem. The reported long term results of mid-stem modular revision implants are good as in most, over 90% survivorship. The introduction of modularity appears to have overcome initial disadvantage of the Wagner stem, i.e. its unpredictability in terms of leg length

Cementless stem fixation is a widely used method of stem revision in North America and elsewhere in the world. There is abundant literature in its support. Most of the reports from 1985 to 2005 related to proximally or extensively porocoated designs, the former falling into disfavor with time because of unpredictable outcomes. With few exceptions (eg S-ROM) the modularity of these designs was limited to the head/neck junction. But this generation of designs was associated with some issues such as insertional fractures, limited control of anteversion (and risk of dislocation), limited applicability in the setting of severe bone loss (Paprosky Type 4 osteolysis or Vancouver Type B3 periprosthetic fracture), as well as ongoing concern relating to severe proximal stress shielding. In the past decade we have seen the mounting use of a new design concept: tapered fluted titanium stems (TFTS), which incorporate the advantages of titanium (for less flexural rigidity), conical taper (for vertical taper-lock stability), longitudinal ribs and flutes (for rotational stability), and surface preparation which attracts bone on growth for long term fixation. Four consecutive reports from our center have documented the superiority of the TFTS in our hands, with encouraging outcomes even when dealing with severe bone loss or periprosthetic fractures. There is an increasing body of other literature which reports a similar experience. Furthermore, with increasing experience and confidence in this design, we now use a monoblock or non-modular design in greater than 95% of cases in which a TFTS is indicated at our center. This circumvents the potential drawbacks of stem modularity, including taper corrosion and taper junction fracture

Failure of internal fixation of intertrochanteric fractures is associated with delayed union or malunion resulting in persistent pain and diminished function. We evaluated 15 elderly patients treated with a tapered, fluted, modular, distally fixing cementless stem. At an average follow up of 2.86 years, mean Harris hip score improved from 35.90 preoperatively to 83.01 (P < 0.01). Fourteen stems had stable bony ingrowth and one stem was loose. Distal fixation with a tapered fluted modular cementless stem allows stable fixation with good functional outcome in a reproducible fashion in this challenging cohort of patients

Cementless stem fixation is a widely used method of stem revision in North America and elsewhere in the World. There is abundant literature in its support. Most of the reports from 1985 to 2005 related to proximally or extensively porocoated designs, the former falling into disfavor with time because of unpredictable outcomes. With few exceptions (eg S-ROM) the modularity of these designs was limited to the head/neck junction. But this generation of designs was associated with some issues such as insertional fractures, limited control of anteversion (and risk of dislocation), limited applicability in the setting of severe bone loss (Paprosky Type 4 osteolysis or Vancouver Type B3 periprosthetic fracture), as well as ongoing concern relating to severe proximal stress shielding. In the past decade we have seen the mounting use of a new design concept: tapered fluted titanium stems (TFTS), which incorporate the advantages of titanium (for less flexural rigidity), conical taper (for vertical taper-lock stability), longitudinal ribs and flutes (for rotational stability), and surface preparation which attracts bone on growth for long term fixation. Four consecutive reports from our center have documented the superiority of the TFTS in our hands, with encouraging outcomes even when dealing with severe bone loss or periprosthetic fractures. There is an increasing body of other literature which reports a similar experience. Furthermore, with increasing experience and confidence in this design, we now use a monoblock or non-modular design in greater than 95% of cases in which a TFTS is indicated at our center. This circumvents the potential drawbacks of stem modularity, including taper corrosion and taper junction fracture

Introduction:. Severe bone loss creates a challenge for fixation in femoral revision. The goal of the study was to assess reproducibility of fixation and clinical outcomes of femoral revision with bone loss using a modular, fluted, tapered distally fixing stem. Methods:. 92 consecutive patients (96 hips) underwent hip revision surgery using the same design of a modular, fluted, tapered titanium stem between 1998 and 2005. Fourteen patients with 16 hips died before a 2-year follow-up. Eighty hips were followed for an average of 11.3 years (range of 8 to 13.5 years). Bone loss was classified as per Paprosky's classification, osseointegration assessed according to a modified system of Engh et al, and Harris Hip Score was used to document pain and function. Serial radiographs were reviewed by an independent observer to assess subsidence, osseointegration and bony reconstitution. Results:. The average patient age was 68 years at the time of surgery (range 40 to 91). 80% hips had at least Paprosky type 3A proximal bone loss and 41% had an associated proximal femoral ostoetomy. Pre-operative Harris Hip scores (HHS) averaged 50.368 (range 22 to 72.775) and improved to an average HHS of 87.432 (range 63.450 to 99.825) at last follow-up. The HHS improved an average of 37.103 points (range 13.750 to 58.950). Radiographically, osseointegration was evident in all hips. No hips had measurable migration beyond 5 mm. 61%) hips had evidence of bone reconstitution and 27% demonstrated diaphyseal stress shielding. One well-fixed distal stem was revised for stem fracture, and two proximal segments were revised for recurrent dislocation. Conclusion:. Reproducible fixation and clinical improvement were consistently achieved with this stem design in the setting of femoral bone loss

The Unified Classification System (UCS), or Vancouver system, is a validated and widely used classification system to guide the management of periprosthetic femoral fractures. It suggests that well-fixed stems (type B1) can be treated with fixation but that loose stems (types B2 and B3) should be revised. Determining whether a stem is loose can be difficult and some authors have questioned how to apply this classification system to polished taper slip stems which are, by definition, loose within their cement mantle. Recent evidence has challenged the common perception that revision surgery is preferable to fixation surgery for UCS-B periprosthetic fractures around cemented polished taper slip stems. Indications for fixation include an anatomically reducible fracture and cement mantle, a well-fixed femoral bone-cement interface, and a well-functioning acetabular component. However, not all type B fractures can or should be managed with fixation due to the risk of early failure. This annotation details specific fracture patterns that should not be managed with fixation alone.

Cite this article: Bone Joint J 2023;105-B(5):481–486.

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: Failure of internal fixation of intertrochanteric fractures may be associated with delayed union or malunion resulting in persistent pain and diminished function. The purpose of this study is to evaluate results of the use of a tapered, fluted, modular, distally fixing cementless stem in the management of failed treatment of intertrochanteric hip fractures in elderly patients. Methods: 837 patients had internal fixation of intertrochanteric fractures over a seven year period (2000–2007) at our institution. Of these, 15 patients with mean age of 80.6 years (69.8–92.3), underwent hip arthroplasty for failure of internal fixation. Clinical and radiographic records of these patients were evaluated. Results: At an average follow up of 2.86 (2–4.5) years, all patients showed marked functional improvement with change in mean Harris hip score from 35.90 to 83.01 (P < 0.01). Fourteen stems had stable bony ingrowth and one stem was loose and subsided by 5 mm. Three patients used a walker for ambulation, ten patients used a cane and two could ambulate without aids. Conclusion: Use of a tapered fluted modular cementless stem allows stable distal fixation in a reproducible fashion with good functional outcome in this challenging cohort of patients. All patients were ambulatory, however majority used walking aids

A mild degree of femoral deformity can be accommodated in total hip replacement by using a small, cemented stem, but this results in abnormal mechanics and potentially early failure. Minor degrees of rotatory and angular deformity proximal to the lesser trochanter can be handled by a custom or modular implant, which will allow changes in version and offset. Deformities below the lesser trochanter should be corrected by osteotomy. This is true of rotational and angular deformity. Where there is a leg length problem, a shortening osteotomy can be carried out at the subtrochanteric region. To achieve angular stability after osteotomy, full canal fill over 5 cm or more is preferable. The rotational stability can be achieved by step cuts, side plates, etc. If the implant is distally fluted with thin, sharp flutes and if it is capable of giving proximal rotational control then simple horizontal butt joint osteotomy is all that is required. The osteotomy should be carried out at the summit of the deformity and proximal and distal prophylactic cerclage wiring is advised. If the gluteal muscles are weak as they may be in a high DDH case, a subtrochanteric osteotomy will allow leg length balancing, correction of proximal anteversion, and if the proximal fragment is retrograde reamed exiting through the neck cut rather than the periform fossa, lateralisation to increase the gluteal power can be achieved

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 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. A classification of femoral deficiency has been developed and an algorithmic approach to femoral reconstruction is presented. An extensively coated, diaphyseal filling component reliably 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. Based on our results, the following reconstructive algorithm is recommended for femoral reconstruction in revision total hip arthroplasty. Type I: In a Type I femur, there is minimal loss of cancellous bone with an intact diaphysis. 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 a Type II femur, there is extensive loss of the metaphyseal cancellous bone and thus, fixation with cement is unreliable. 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: In a Type IIIA femur, the metaphysis is non-supportive and an extensively coated stem of adequate length is utilised to ensure that more than 4cm of scratch fit is obtained in the diaphysis. Type IIIB: Based on the poor results obtained with a cylindrical, extensively porous coated implant (with 4 of 8 reconstructions failing), our present preference is a modular, cementless, tapered stem with flutes for obtaining rotational stability. 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 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

The fixation concept of a fluted, conical, tapered grit-blasted titanium stem has been employed successfully in Europe, but the experience in North America with implants of this design is more limited. The most commonly studied stem of this design, the Wagner stem has been reported to provide good pain relief function and implant stability in several aeries, although large series with long-term follow-up are lacking. Implants with a similar distal geometry but modular proximal features were introduced in an attempt to solve one of the practical difficulties of using a stem of this design: determining where the implant would seat was difficult, trialing options were limited, and accurate leg length and soft tissue balancing were difficult. Modular implants are more user-friendly but have the theoretical disadvantage of introducing the potential for modular junction failure (failure due to fatigue or fretting). To date, there are only limited (but favourable) short-term reported results on the efficacy of this form of revision. Implants of this design can be used when rotational stability, axial stability, and long-term implant fixation must be gained primarily from the distal diaphysis of the femur. Examples include patients with periprosthetic femur fractures and patients with marked proximal bone thinning but good diaphyseal bone. From the practical viewpoint, the fluted section of these implants must be straight (to allow milling of a cone-shaped diaphysis) and thus anterior cortical perforation is a potential complication. Anterior extended osteotomy as described by Wagner accomplishes the goal of femoral exposure and helps prevent distal anterior femoral perforation

Using an institutional database we have identified over 1000 femoral revisions using extensively porous-coated stems. Using femoral re-revision for any reason as an endpoint, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified pre-revision bone stock as a factor affecting femoral fixation. When the cortical damage involved bone more than 10cm below the lesser trochanter, the survivorship, using femoral re-revision for any reason or definite radiographic loosening as an endpoint, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky Type 3B and 4 femoral defects, there are rare patients with femoral canals smaller than 13.5mm or larger than 26mm that are not well suited to this technique. Eight and 10 inch stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

The unacceptable failure rate of cemented femoral revisions led to many different cementless femoral designs employing fixation in the damaged proximal femur with biological coatings limited to this area. The results of these devices were uniformly poor and were abandoned for the most part by the mid-1990's. Fully porous coated devices employing distal fixation in the diaphysis emerged as the gold standard for revisions with several authors reporting greater than 90% success rate 8–10 years of follow-up. Surgical techniques and ease of insertion improved with the introduction of the extended trochanteric osteotomy as well as curved, long, fully porous coated stems with diameters up to 23mm. The limits of these stems were stretched to include any stem diameter in which even 1–2cm of diaphyseal contact could be achieved. When diaphyseal fixation was not possible (Type IV), the alternatives were either impaction grafting or allograft prosthetic composite (APC). As the results of fully porous coated stems were very carefully scrutinised, it became apparent that certain types of bone loss did not yield the most satisfactory results both clinically and radiographically. When less than 4cm of diaphyseal press fit (Type IIIB) was achieved, the mechanical failure rate (MFR) was over 25%. It also became apparent that even when there was 4–6cm diaphyseal contact (Type IIIA), and the stem diameter was 18mm or greater, post-operative pain and function scores were significantly less than those with smaller diameter stems. This was probably due to poorer quality bone. Many of these Type IIIA and Type IIIB femurs had severe proximal torsional remodeling leading to marked distortion of anteversion. This made judging the amount of anteversion to apply to the stem at the time of insertion very difficult, leading to higher rates of dislocation. These distortions were not present in Type I and Type II femurs. This chain of events which was a combination of minimal diaphyseal fixation, excessively stiff stems and higher dislocation rates led to the conversion to modular type stems when these conditions existed. For the past 13 years, low modulus taper stems of the Wagner design have been used for almost all Type IIIA and Type IIIB bone defects. The taper design with fluted splines allows for fixation when there is less than 2cm of diaphysis. The results in these femurs even with diameters of up to 26mm have led to very low MFRs and significantly less thigh pain. Independent anteversion adjustment is also a huge advantage in these modular stems. Similar success rates, albeit with less follow-up, have been noted in Type IV femurs

Ten to 15% of the pelvic girdle tumors are primary malignant bone tumors, while about 80% are osseous metastases. Due to improved function, enhanced quality of life, and acceptable local recurrence rates, limb salvage surgery has replaced external hemipelvectomies in many cases of primary malignancies. However, large segmental bony defects and poor bone quality due to the disease process itself and subsequent treatment (i.e. chemotherapy and radiation) can make stable implant fixation difficult when performing a total hip arthroplasty (THA) for oncologic periacetabular lesions with concurrent fractures. Various methods are available to reconstruct the hemipelvis, and include large structural allografts, allograft-prosthetic composites (APCs), custom-made endoprostheses, modular saddle prostheses, and modular hemipelvis endoprostheses. However, short- and mid-term results from our institution indicate that tantalum reconstructions with adjuvant screw fixation and supplemental reinforcement cages provide reasonable improvement in clinical outcomes and stable fixation in situations with massive bone loss and compromised bone quality. On the femoral side, cemented fixation remains a viable option (including proximal femoral replacements), but uncemented distal fixation with extensively-porous coated cylindrical stems or modular fluted tapered stems can be considered if the disease process (or subsequent treatment) primarily affects the proximal femur. In addition to long-term fixation, post-operative dislocations remain a significant concern given the often compromised abductor mechanism

Periprosthetic femoral fractures are increasing in incidence, and typically occur in frail elderly patients. They are similar to pathological fractures in many ways. The aims of treatment are the same, including 'getting it right first time' with a single operation, which allows immediate unrestricted weightbearing, with a low risk of complications, and one that avoids the creation of stress risers locally that may predispose to further peri-implant fracture. The surgical approach to these fractures, the associated soft-tissue handling, and exposure of the fracture are key elements in minimizing the high rate of complications. This annotation describes the approaches to the femur that can be used to facilitate the surgical management of peri- and interprosthetic fractures of the femur at all levels using either modern methods of fixation or revision arthroplasty.

Cite this article: Bone Joint J 2023;105-B(6):593–601.

Aims

There are limited long-term studies reporting on outcomes of the Zimmer Modular Revision (ZMR) stem, and concerns remain regarding failure. Our primary aim was to determine long-term survival free from all-cause revision and stem-related failure for this modular revision stem in revision total hip arthroplasty (THA). Secondary aims included evaluating radiological and functional outcomes.

We maintain a database on 1000 femoral revisions using extensively porous-coated stems. Using femoral rerevision for any reason as an endpoint, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified prerevision bone stock as a factor affecting femoral fixation. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral rerevision for any reason or definite radiographic loosening as an endpoint, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10 inch stems 13.5 mm or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Using an institutional database we have identified over 1000 femoral revisions using extensively porous-coated stems. Using femoral re-revision for any reason as an endpoint, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified pre-revision bone stock as a factor affecting femoral fixation. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral re-revision for any reason or definite radiographic loosening as an endpoint, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects, there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10 inch stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

There is a paucity of available literature to guide the surgeon treating postoperative fractures of the greater trochanter after femoral component revision. Between 2009 and 2016, 133 patients underwent femoral component revision by the senior author utilizing a modular tapered fluted titanium stem. 17 patients died or had inadequate follow-up. Therefore, 116 patients were included in the final analysis. There were 58 males and 58 females with a mean age of 64 (range 23 to 91 years old). Clinical and radiographic data were analyzed for postoperative greater trochanteric fracture (GTfx). Mean clinical follow up was 21 months (range 3 to 77 mos). Age, BMI, preoperative diagnosis, comorbidities, reason for revision, use of Extended Trochanteric Osteotomy (ETO), fixation method of ETO, presence of prior hardware, post-operative trauma (falls), femoral component size and offset, change in leg length were analyzed to determine potential risk factors for postoperative GT fracture. There were 7 postoperative greater trochanteric fractures in 7 patients (6%). Of these, 1 occurred as a result of a postoperative fall, 1 occurred after dislocation, and 1 occurred after a fall with a subsequent dislocation. The mean time to diagnosis of the fracture was 10.7 weeks postoperatively (range one day to 37.4 weeks). 52 of 116 patients had their revision performed through an ETO. Of those, 6 had a postoperative fracture of the GT. The use of an ETO significantly increased the likelihood of postoperative GT fx (p=0.035). Regarding femoral component size, use of a longer proximal body (+10 or greater) was associated with an increased risk of postoperative GT fx (p=0.07). Two fractures were minimally (<1cm) or non-displaced and were treated non-operatively. Of these fractures, 1 united. The other fracture further displaced and resulted in recurrent instability. This was treated with excision of the fragment and a constrained liner. 5 fractures were displaced and were treated with ORIF. 3 were fixed with a cable grip device, 1 was plated, and 1 was treated with a cable grip device and a constrained liner. Of those treated with some form of ORIF, all 5 healed. Of those that underwent surgical fixation initially, 3 reported residual trochanteric pain and 1 patient had their hardware removed (trochanteric claw). 2 of these patients have a residual limp and require a cane for use as a gait aid. The patient treated non-surgically required a cane as did the patient that failed non-surgical treatment. Post-operative greater trochanteric fractures are a rare complication of femoral component revision. The use of an ETO significantly increased the rate of post of GTfx. The mean time to diagnosis of was 11 weeks. Displaced fractures of the greater trochanter treated with ORIF all healed, both cable grip devices and plates were effective. Residual limp requiring gait aids and residual trochanteric pain were common outcomes after fixation of these fractures despite successful union

The femoral diaphysis presents the best opportunity for fixation during revision THA. Both fully coated cylindrical and modular fluted tapered titanium stems have demonstrated excellent results. Cylindrical stems have demonstrated concerning rates of failure when used in larger, osteopenic canals or in canals with post-isthmal divergent morphologies. Modular stems offer the advantage of separating distal fixation needs from proximal version, leg length, and offset needs via a modular junction. Although early designs demonstrated some breakages at the taper or through thin proximal bodies, newer generation implants have not demonstrated such mechanical concerns. Additionally, the modular junctions do not appear to be having any problems with corrosion. Mid- to long-term data with various designs now support the safety and efficacy of these constructs that can handle a wide variety of challenges during femoral revision. Careful attention to detail is necessary to minimise the risk of subsidence and intra-operative fracture or femoral perforation

The technique involves impaction of cancellous bone into a cavitary femur. If segmental defects are present, the defects can be closed with stainless steel mesh. The technique requires retrograde fill of the femoral cavity with cancellous chips of appropriate size to create a new endomedullary canal. By using a set of trial impactors that are slightly larger than the real implants the cancellous bone is impacted into the tube. Subsequent proximal impaction of bone is performed with square tip or half moon impactors. A key part of the technique is to impact the bone tightly into the tube especially around the calcar to provide optimal stability. Finally a polished tapered stem is cemented using almost liquid cement in order to achieve interdigitation of the implant to the cancellous bone. The technique as described is rarely performed today in many centers around the world. In the US, the technique lost its interest because of the lengthy operative times, unacceptable rate of peri-operative and post-operative fractures and most importantly, owing to the success of tapered fluted modular stems. In centers such as Exeter where the technique was popularised, it is rarely performed today as well, as the primary cemented stems used there, rarely require revision. There is ample experience from around the globe, however, with the technique. Much has been learned about the best size and choice of cancellous graft, force of impaction, surface finish of the cemented stem, importance of stem length, and the limitations and complications of the technique. There are also good histology data that demonstrate successful vascularization and incorporation of the impacted cancellous bone chips and host bone. Our experience at the clinic was excellent with the technique as reported in CORR in 2003 by M Cabanela. The results at mid-term demonstrated minimal subsidence and good graft incorporation. Six of 54 hips, however, had a post-operative distal femoral fracture requiring ORIF. The use of longer cemented stems may decrease the risk of distal fracture and was subsequently reported by the author after reviewing a case series from Exeter. Today, I perform this technique once or twice per year. It is an option in the younger patient, where bone restoration is desired. Usually in a Paprosky Type IV femur, where a closed tube can be recreated and the proximal bone is reasonable. If the proximal bone is of poor quality, then I prefer to perform a transfemoral osteotomy, and perform an allograft prosthetic composite instead of impaction grafting, and wrap the proximal bone around the structural allograft. I prefer this technique as I can maintain the soft tissues over the bone and avoid the stripping that would be required to reinforce the bone with struts or mesh. Another indication for its use in the primary setting is in the patient with fibrous dysplasia

Aims

The aim of this study was to evaluate the incidence of liner malseating in two commonly used dual-mobility (DM) designs. Secondary aims included determining the risk of dislocation, survival, and clinical outcomes.

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

The use of tapered, fluted, modular, distally fixing stems has increased in femoral revision surgery. The goal of this retrospective study was to assess mid- to long-term outcomes of this implant in femoral revision with bone loss. Seventy-one hips in 70 patients with a mean age of 68.5 years were followed for an average of 10 years. Pre-operative HHS averaged 50 and improved to an average of 87 post-operatively. Seventy-nine percent hips had Paprosky type 3A, 3B or 4 bone-loss and 44% had an associated proximal femoral osteotomy. All stems osseointegrated distally (100%). Two hips subsided >5mm (mean 8mm) but achieved secondary stability. Sixty-eight percent hips had evidence of bony reconstitution and 21% demonstrated diaphyseal stress-shielding. One stem fractured at its modular junction and was revised with a mechanical failure rate of 1.4%. Distal fixation and clinical improvement were reproducibly achieved with this stem design

The use of tapered, fluted, modular, distally fixing stems has increased in femoral revision surgery. The goal of this retrospective study was to assess mid-term to long-term outcomes of this implant in femoral revision with bone-loss. Seventy-one hips in 70 patients with a mean age of 68.5 years were followed for an average of 10 years. Preoperative HHS averaged 50 and improved to an average of 87 postoperatively. Seventy-nine percent hips had Paprosky type 3A, 3B or 4 bone-loss and 44% had an associated proximal femoral osteotomy. All stems osseointegrated distally (100%). Two hips subsided >5mm (mean 8mm) but achieved secondary stability. Sixty-eight percent hips had evidence of bony reconstitution and 21% demonstrated diaphyseal stress- shielding. One stem fractured at its modular junction and was revised with a mechanical failure rate of 1.4%. Distal fixation and clinical improvement were reproducibly achieved with this stem design

Aims

With increasing burden of revision hip arthroplasty (THA), one of the major challenges is the management of proximal femoral bone loss associated with previous multiple surgeries. Proximal femoral arthroplasty (PFA) has already been popularized for tumour surgeries. Our aim was to describe the outcome of using PFA in these demanding non-neoplastic cases.

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

Peri-prosthetic fractures of the femur around a THA remain challenging injuries to treat. The Vancouver Classification helps to guide decision making, and is based on fracture location, implant fixation status, and remaining bone quality. It is critical to determine fixation status of the implant, even if surgical dislocation is necessary. Type A fractures involve the trochanters, and are usually due to osteolysis. Revision of the bearing surface and bone grafting of the lesions can be effective. Type B1 fractures occur around a well fixed stem, typically at the stem tip. Internal fixation with laterally based locked cable plates is effective. Optimising proximal fixation is important, typically with locked screws and cables. Allograft struts are probably unnecessary with modern angle stable plates. Type B2 and B3 fractures are treated with revision, either with a fully coated cylindrical or a modular fluted tapered titanium stem. Distal fixation should be optimised, while preserving vascularity to proximal bony fragments. The « internal scaffold » technique has been described with excellent results. Rarely, a proximal femoral replacement is necessary. Careful attention to detail and clear knowledge of stem fixation status is necessary for a good outcome

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

As the incidence of total hip arthroplasty (THA) rises, an increasing prevalence of peri-prosthetic femur fractures has been reported. This is likely due to the growing population with arthroplasties, increasing patient survival and a more active life-style following arthroplasty. It is the 3rd most common reason for THA reoperation (9.5%) and 5th most common reason for revision (5% with fracture risk after primary THA reported at 0.4%-1.1% and after revision at 2.1%-4%). High quality radiographs are usually sufficient to classify the fracture and plan treatment. Important issues in treatment include stem fixation status and fracture location relative to the stem. Additional comorbidities will also influence treatment choices, of which the most critical is the presence of infection and the quality of bone stock. The most commonly studied, and reported classification system is the Vancouver. Type A are peri-trochanteric fractures with AL at the lesser and AG at the greater trochanter. B fractures are those around the stem with B1 fractures having a well-fixed stem, B2 a loose stem with adequate bone stock, and B3 representing loose stem and inadequate bone stock. C fractures are distal to the stem. Type A) Trochanteric Fractures: These are usually associated with lysis. Displaced fractures can be managed adequately with cerclage fixation and cancellous allograft to fill osteolytic defects. Undisplaced fractures usually heal well with symptomatic treatment. Type B) Fractures Around the Stem: The B1 type has a well-fixed component and is usually treated with extramedullary fixation plus graft. Contemporary plates have been designed specifically for these fractures. Strut allograft may be used to provide a more rigid construct. Spiral and long oblique fractures can be cerclaged while short oblique or transverse fractures require fixation anterior and lateral with cable plates and cortical strut grafts. Screws can be used distal to the implant, and cables used proximally. The B2 type has a loose prosthesis but otherwise good bone stock. In this setting, the fracture line may be extended on the lateral cortex of the femur as an extended osteotomy to provide easy access for cement removal. These fractures can be managed with an extensively coated stem if rotational stability can be obtained in the distal segment. If rotational stability over a 4 cm scratch interference fit of the stem isn't possible, then a fluted tapered modular stem should be used. Strut allografts improve initial stability. The B3 type has both a loose prosthesis and poor bone stock and in the younger patient restoration of bone stock should be a priority. Bulk femoral grafts may be needed. The elderly or low functional demand patient may be treated with a proximal femoral replacement. Because of soft-tissue deficiencies, a constrained acetabular liner may be needed to prevent instability. Type C) Fractures Distal to the Stem: These usually accompany a stable stem and many fixation devices are available. Locking plates have become most popular and should be secured with cerclage wires proximally around the component with screws distally. Retrograde nails may be employed if there is adequate bone distal to the stem tip and above the fracture

Modularity in femoral revision evolved to address the specific weaknesses in the execution and results of the early Wagner SL stem, namely dislocations and subsidence. With modularity, distal canal fit can be achieved independently, and the proximal geometry can be created to re-establish the leg length and offset. The benefits of modularity relate specifically to being able to modify a plan intra-operatively based on the conditions that are encountered in mid battle. Inherent in this concept is the principle of predictability. The extent to which the conditions of operation may change requires alternatives to manage those changes. More importantly we need to be able to predict how an implant will sit in the bone. At the inception and with subsequent manifestations of modular fluted stems, our ability to predict where the final implant will seat based on the trial options that existed was poor. For this reason, some modular stem designs offered no trial. This was part of the imperative for modularity, so that if the implant set too high it could be easily removed with reaming a little deeper and put back in. If the stem sat more deeply than had been anticipated, the change could be compensated by an alteration in the proximal modular segment. Reproducible mid- to long-term results have been published with this type of stem. Potential negatives of the modular junction include stem breakage, fretting and corrosion, cost, and the need to accommodate a large sized proximal segment within the proximal femur. The most important feature in modern non-modular implants will be predictability. We need to be able to predict that the final reamer will sit at a particular level in the femoral bone, and the trial will reproduce this level, and the final implant will reproduce this level. More importantly, we need to be able to predict that implants will remain where they are put, and not subside. Subsidence has been causally associated with implant under-sizing, which is an error in surgical execution. As such, design features that optimise the ability to achieve intimate and broad endosteal contact between the implant and the bone can help reduce subsidence. These include precise, sharp reamers, implants in 1 mm increments, and trials that reproduce the position of the final implant. A larger implant is less likely to break, and we recommend preparation for the largest implant that the diaphysis can accommodate, often evident in the tactile feedback from the reamer, and the quality of the reamed bone being removed. Reaming is performed eccentrically in the proximal femur, so as to engage the diaphysis optimally. The need for a kink in the stem is important for modular stems, which have bulky proximal segments that can create conflict with the peritrochanteric bone in smaller patients. Non-modular stems can have a smaller proximal diameter, such that a straight stem can be accommodated in most revision cases. Early follow-up of a modern non-modular stem has shown excellent clinical improvement and reproducible ingrowth. Subsidence of > 10 mm occurred in 6 hips (6%), which is a notable improvement in historical values for this stem type, but remain short of some reports with modular stems. Improvements in goals and techniques of reaming and implantation are surely part of the improvements that have been documented, as well as those yet to be realised. Predictability will lead to simplicity and intuitiveness

I use monolithic, cylindrical, fully porous coated femoral components for many femoral revisions. Our institutional database holds information on 1000 femoral revisions using extensively porous-coated stems. To date, 27 stems have been re-revised (14 for loosening, 4 for infection, 7 for stem fracture, 2 at time of periprosthetic femoral fracture). Using femoral re-revision for any reason as an end point, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified pre-revision bone stock as a factor affecting femoral fixation. Among the 777 femoral revisions graded for femoral bone loss, 59% of the femurs were graded as having no cortical damage before the revision, 29% had cortical damage extending no more than 10 cm below the lesser trochanter, and 12% had cortical damage that extended more than 10 cm below the lesser trochanter. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral re-revision for any reason or definite radiographic loosening as an end point, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10” stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Prevention: Many periprosthetic femur fractures may be prevented by: good patient follow-up; timely reoperation of lytic lesions if radiographs suggest fracture risk; prophylactic use of longer stemmed implants or strut grafts to bypass cortical defects at revision surgery. Treatment: Periprosthetic fractures can be treated using an algorithmic approach based on the Vancouver classification system. Fractures of greater or lesser trochanter (Type A): nonoperative treatment if displacement acceptable and if not associated with lysis; operative treatment if displacement unacceptable or associated with progressive lysis. Fractures of distal femur well distal to implant (Type C): treat as any other femur fracture, usually operatively; fixation options: plate/retrograde nails. Fractures around the implant or at its tip (Type B): these fractures almost always require surgery. Nonoperative treatment is associated with high rate of malunion, nonunion, poor results. Treatment is according to fixation status of implant and bone quality. Well-fixed stem (Type B1): ORIF with cable plate and/or strut grafts; or with locking plate and minimally invasive biologic technique. Loose stem (Type B2 and Type B3): revise implant to long stem; usually use uncemented distally-fixed implant; occasionally long cemented stem (avoid cement extrusion). In most cases we favor use of a modular fluted tapered stem which provides axial and rotational stability by fixation distal to the fracture. Principles: obtain fracture stability, implant stability, and optimise conditions for bone healing (use bone grafts, don't strip periosteum)

I prefer monolithic, cylindrical, fully porous coated femoral components for most femoral revisions. Our institutional database holds information on 1000 femoral revisions using extensively porous-coated stems. To date, 27 stems have been rerevised (14 for loosening, 4 for infection, 7 for stem fracture, 2 at time of periprosthetic femoral fracture). Using femoral rerevision for any reason as an end point, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified prerevision bone stock as a factor affecting femoral fixation. Among the 777 femoral revisions graded for femoral bone loss, 59% of the femurs were graded as having no cortical damage before the revision, 29% had cortical damage extending no more than 10cm below the lesser trochanter, and 12% had cortical damage that extended more than 10cm below the lesser trochanter. When the cortical damage involved bone more than 10cm below the lesser trochanter, the survivorship, using femoral rerevision for any reason or definite radiographic loosening as an end point, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5mm or larger than 26mm that are not well suited to this technique. Eight and 10-inch stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Vancouver A: If minimal displacement and prosthesis stable can treat nonoperatively. If displacement is unacceptable and/or osteolysis is present consider surgery. AL: Rare, avulsions from osteopenia and lysis. If large, displaced and include large portion of calcar-can destabilise stem and prompt femoral revision. AG: More common. Often secondary to lysis. Does not usually affect implant stability. Minimal displacement. Treat closed × 3 months. Revise later is needed to remove the particle generator, debride defects and bone graft. Displaced with good host bone stock. Consider early ORIF and bone grafting. Vancouver B:. B1: Rarely non-operative. ORIF with femoral component retention. Need to carefully identify stem fixation. B2's classified as B1's are doomed to fail. B1's correctly identified treated with plate, allograft struts or both. High union rates with component retention. B2: Femoral revision +/− strut allograft. Best results seen with patients revised with uncemented, extensively porous coated femoral stems. May use modular, fluted taper stems. B3: Proximal femoral replacement - Tumor prosthesis, Allograft Prosthetic Composite (APC). Uncemented femoral stem - Extensively porous coated, Fluted, tapered stem, Allograft strut. Vancouver C: Treat with standard fracture techniques. These fractures are away from the femoral prosthesis. Rarely nonoperative. Fixation options – Cerclage, Strut Allograft, Plate fixation, Retrograde IM nail, or a Combination thereof. Avoid stress risers between implants. Bypass (overlap) fixation. Consider allowing 2.5 cortical diameters between devices

INTRODUCTION: 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 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. DISCUSSION: An extensively coated, diaphyseal filling component reliably 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. Based on our results, the following reconstructive algorithm is recommended for femoral reconstruction in revision total hip arthroplasty: TYPE I: In a Type I femur, there is minimal loss of cancellous bone with an intact diaphysis. 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 a Type II femur, there is extensive loss of the metaphyseal cancellous bone and thus fixation with cement is unreliable. In this cohort of patients, successful fixation was achieved using a diaphyseal fitting, extensively porous coated implant in 26 of 29 cases (90%) However, as the metaphysis is supportive, a cementless implant that achieves primary fixation in the metaphysis can be utilized. TYPE III A: In a Type IIIA femur, the metaphysis is non-supportive and 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 III B: Based on the poor results obtained with a cylindrical, extensively porous coated implant, our present 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 impacting the femoral component as far distally as needed while then building up the proximal segment to restore appropriate leg length. TYPE IV: In a Type IV femur, 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 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

The S-ROM stem is distally circular canal filling with thin sharp flutes which engage the endosteal cortex. The rotational stability produced by this is 37 Nm, which exceeds the service loads on the hip of 22 Nm. The distal canal fill prevents varus and valgus displacement. The porous-coated proximal sleeve provides resistance to vertical sink and also excludes the distal stem from the effective joint space. The primary stem is straight and the long stem is bowed with a 15 degrees anteversion twist proximally. The neck comes in lengths from 30 to 46mm with varying offset. The sleeves come in variable size and geometry. The stem choice in revision surgery is based on the Scoot Diamond Classification. Type 1 (this is going to be easy) is a primary stem. Type 2 (this is going to be difficult) implies diaphyseal bone loss and will require a long stem. Type 3 (Oh My God), implies more than 70mm of completely missing proximal femur and will require a structural allograft cemented to the sleeve. Results. The follow-up is from 2 to 22 years. There were 119 primary stems. Revisions for aseptic loosening were zero. One stem was removed for late sepsis at nine years. There were 262 long stem cases. Stem revision for aseptic loosening occurred in nine cases (3.7%). Four became loose because of inappropriate and obsolete techniques of allografting, one for non-union of a subtrochanteric osteotomy and four for failure of ingrowth into the sleeve. Four were revised for late sepsis. Structural allografts comprised seven cases. Three were revised at years 7, 11 and 16. Conclusion. The revision rate for aseptic loosening in hip revision cases is acceptably low. Other issues such as late polyethylene wear and dislocation continue to decrease

Aims

The aim of this study was to determine whether fixation, as opposed to revision arthroplasty, can be safely used to treat reducible Vancouver B type fractures in association with a cemented collarless polished tapered femoral stem (the Exeter).

Twenty-Six total hip arthroplasties were performed in Crowe grade 3 or 4 hip dysplasia using subtrochanteric shortening osteotomy with 2-kinds of femoral stem(Primary monoblock and modular femoral stem). The average age was 46.2 years, and the average follow-up was 4.1 years. Acetabular reconstruction with structural autograft was used in 13 hips. Radiologically, hip centers were nearly normalized by vertical height of 10.6mm elevation and horizontal lengths of 1.7mm compared with uninvolved sites. Three of four osteotomy nonunions were managed with bone graft and other one wating for surgery. One acetabular revision was performed for migration. One postoperative dislocation was managed successfully with closed reduction and abduction brace. One patient (> 7cm) showed postoperative neurologic complications was noted. Harris hip score was improved from 35.6 to 81.7. A cementless modular distal fluted femoral stem is a useful device in these patients

Introduction. Studies have documented encouraging results with the use of fluted, tapered, modular, titanium stems in revision hip arthroplasty with bone loss. However, radiographic signs of osseointegration and patterns of reconstitution have not been previously categorized. Materials and Methods. 64 consecutive hips with index femoral revision using a particular stem of this design formed the study cohort. Serial radiographs were retrospectively reviewed by an independent observer. Bone loss was determined by Paprosky's classification. Osseointegration was assessed by a slight modification of the criteria of Engh et al. Femoral restoration was classified according to Kolstad et al. Pain and function was documented using Harris Hip Score (HHS). Results. Mean patient age was 68.3 years and radiographic follow-up 6.2 years. 74% femora had type 3 or 4 bone loss. All distal segments were radiographically osseointegrated. Proximal segment radiolucent lines were frequent (40%). Early minor subsidence occured in 4 (6.2%) hips. Definite bony regeneration was documented in 73% femora and stress-shielding in 26%. HHS improved from a pre-operative mean of 50.1 points to 86.2 at most recent follow-up. Discussion. A consistent pattern of bony remodeling and osseointegration occurred which could be applied for assessment of fixation and stability of this stem. The well established criteria of osseointegration for cylindrical cobalt-chrome stems may have to be altered for application to these stems as the mechanism of load transfer is entirely different. Stems with diameter of 18mm or greater are clearly predisposed to stress shielding, predominantly at the mid-shaft region

Background. Recently the taper wedged stems (TWS) are used widely in Japan because of good bone fixation and ease of the procedure. However, it is unclear how TWS get initial fixation in Japanese, especially dysplasia hip or elderly patients who had stovepipe canal. The purpose of this study is to evaluate initial bone fixation of the TWS in Japanese using computed tomography and to estimate biological bone fixation of the TWS using the Tomosynthesis. Methods. We evaluated 100 hips underwent primary total hip arthroplasty using TWS. All patients were performed computed tomography within 2 weeks postoperatively and evaluated which part of the canal was made contact with the stem. 24 hips were male and 76 hips were female. According to the canal flare index, 9 hips were champagne flute canal, 80 hips were normal canal and 11 hips were Stovepipe canal. 10 hips were Dorr type A, 80 hips were Dorr type B and 10 hips were Dorr type C. The initial bone fixation was classified as Medio-lateral fit (fixed at Gruen zone 2 and 7), Flare fit (fixed at zone 2 and 6), Varus 2-point fit (fixed at zone 3 and 7), Valgus 3-point fit (fixed at zone 2, 5 and 7), Distal fit (fixed at zone 3 and 5), Total fit (fixed at zone 2,3,5,6 and 7) by the stem A-P view. Moreover, we defined Medio-lateral fit, Flare fit and Total fit as Adequate fit, Varus 2-point fit and Valgus 3-point fit as Varus or Valgus fit, Distal fit as Distal fit. The stem alignment was classified as flexion, neutral and extension by the stem lateral view. Femoral component fixation was graded as bone ingrowth, fibrous ingrowth and unstable by hip radiographs after surgery at 1 year. Spot-welds were evaluated using tomosynthesis after surgery at 6 months. Results. 47 hips were Medio-lateral fit, 7 hips were Flare fit, 9 hips were Varus 2-point fit, 12 hips were Valgus 3-point fit, 17 hips were Distal fit and 8 hips were Total fit by the stem A-P view. 63 hips were Flexion, 36 hips were Neutral and 1 hip was Extension by the stem lateral view. 62 hips were Adequate fit, 21 hips were Varus or Valgus fit and 17 hips were Distal fit. Distal fit was identified all canal shape or bone quality regardless of the Canal flare index, the Dorr classification. There was no case of adequate fit which was used larger stem. All cases achieved bone ingrowth fixation, but there were 5 hips which we could not recognize spot-welds. 4 hips of them were classified as Distal fit. Discussion. The study showed that initial bone fixation of the TWS exits various pattern due to femoral geometry, bone quality and stem size. Also most stems were inserted flexion by the stem lateral view. For all hips, tomosynthesis showed stable osseous fixation of the stem regardless of the type of initial bone fixation. Although it is unclear to affect long-term survivorship by the various type of initial bone fixation

To document the medium term results of the use of a fluted tapered titanium femoral stem in revision total hip arthroplasty. 70 patients undergoing total hip revision using a tapered grit blasted titanium modular stem were reviewed at a mean follow up time of 47 months. No bone graqfts were used. Femoral defects were classified according to Pak and Paprosky and the femoral bone quality was assessed with the Bohm and Bischel system. Clinical function was assessed by the Oxford Hip Score. Radiographic analysis was performed in all cases. The results of the use of this prosthesis compares favourably with other revision stems. The Oxford Hip Scores compare favourably with the results for revisions recorded in the New Zealand National Joint Register (24.3) Although technically demanding this stem offers a very satisfactory solution for revision of total hips in most circumstances

I prefer monolithic, cylindrical, fully porous coated femoral components for most femoral revisions. Our institutional database holds information on 1000 femoral revisions using extensively porous-coated stems. To date, 27 stems have been rerevised (14 for loosening, 4 for infection, 7 for stem fracture, 2 at time of periprosthetic femoral fracture). Using femoral rerevision for any reason as an end point, the survivorship is 99 ± 0.8% (95% confidence interval) at 2 years, 97 ± 1.3% at 5 years, 95.6 ± 1.8% at 10 years, and 94.5 ± 2.2% at 15 years. Similar to Moreland and Paprosky, we have identified prerevision bone stock as a factor affecting femoral fixation. Among the 777 femoral revisions graded for femoral bone loss, 59% of the femurs were graded as having no cortical damage before the revision, 29% had cortical damage extending no more than 10 cm below the lesser trochanter, and 12% had cortical damage that extended more than 10 cm below the lesser trochanter. When the cortical damage involved bone more than 10 cm below the lesser trochanter, the survivorship, using femoral rerevision for any reason or definite radiographic loosening as an end point, was reduced significantly, as compared with femoral revisions with less cortical damage. In addition to patients with Paprosky type 3B and 4 femoral defects there are rare patients with femoral canals smaller than 13.5 mm or larger than 26 mm that are not well suited to this technique. Eight and 10” stems 13.5 or smaller should be used with caution if there is no proximal bone support for fear of breaking. Patients with canals larger than 18 mm may be better suited for a titanium tapered stem with flutes. While a monolithic stem is slightly more difficult for a surgeon to insert than a modular femoral stem there is little worry about taper junction failure

Femoral components in total hip replacements fail in well-known ways. There is vertical sink, posterior rotation and pivot, either distal or mid-stem. In order to sink, the stem moves into valgus and then slides down the inside of the calcar. It does not cut through the calcar. To prevent sink and pivot, a canal filling stem is required. Canal fill prevents the stem from moving into valgus and, therefore, it will not sink. Two centimeters with complete canal fill is adequate in a primary stem. A long stem will give longer canal fill in a revision. Sharp distal flutes will prevent rotation. The distal end of the stem should be polished. One is looking for a distal stability, not distal fixation. If the isthmus is intact, a primary stem can be used. If the isthmus is damaged, a long stem is necessary. If the calcar is intact, a primary neck is adequate. If the calcar is missing down to the level of the lesser trochanter, a calcar replacement neck is required. If there is more than 70 millimeters of completely missing proximal femur, a structural allograft is required. If the proximal femur is damaged, the ability to place a sleeve or collar to seek the best bone available independently of the stem version is very helpful. No matter how poor the proximal bone quality is, it can be supplemented by cerclage wires. The implant will sink only if the cerclage wires break. The advantage of proximal fixation is that loading the proximal femur speeds recovery. The huge disadvantage of distal fixation is removal of the implant should it become necessary. My long term results for the S-ROM stem used in revision are now out over 20 years. There were 119 primary stems with a minimum follow up of 5 years with no revisions for aseptic loosening. There were 262 long stems used. Nine (3.7%) underwent aseptic loosening. Most of these were due to technical errors due to my inexperience in the learning process of revision surgery. Four were dependent on strut-grafts and should have been treated with structural allografts. There were seven cases with structural allografts. Three were revised. Again, these were largely from problems arising from inexperience. I believe proximal modularity with distal stability allows the vast majority of revision cases to be treated with proximal fixation

Aims

To draw a comparison of the pullout strengths of buttress thread, barb thread, and reverse buttress thread bone screws.

We implanted 203 smooth-stemmed femoral components before January 1988. The femoral component used was anatomically shaped, fluted and made of titanium. Thirty-two hips were revised due to mid-thigh pain, and the femoral implant was found to be loose in all. In the 157 patients with a two-year follow-up, the Merle d'Aubigne and pain scores for completely cementless arthroplasties were similar to those for hybrid prostheses (cemented acetabular cup and cementless femoral stem). Of the 145 cases with two-year radiographic follow-up, 59 had extensive radiolucencies and 22 were unstable. The five-year cumulative survival rate was 77%. Implantation of this stem should be restricted to patients in whom cement fixation is contra-indicated

Most studies about hemi-arthroplasty of hip have focused on clinical aspects. Design features of various implants of hemi-arthroplasty have not been studied extensively. The aim was to investigate the relationships between radiological variables and possible mode of failure in various hemiarthroplasty implants in intracapsular neck of femur fractures. A retrospective review of 42 hemi hip arthroplasties, Austin Moore and Thompson prosthesis by Biomet, Medical Product Service (Tipsan) and Smit Medimed (SMPL) used in our hospital. Controversy exists between indication for a particular design in an unselected series of patients once excluding the choice of cementing or uncementing the prosthesis. In monoblock prosthesis not only the head-neck region affects the stability but also the stem fit in proximal femur. Surgeon preference to technique and approach excluded. Premorbidly all patients were mobilising independently. 5 criteria reviewed. 1) head size of prosthesis 2) neck length 3) prosthesis stem shaft angle 4) stem-cortical distance ratio and 5) shape of the femoral canal as classified by Dorr. Head size compared in AP views of involved hip and normal head size compared with that of prosthesis. A difference <2 mm or >3 mm indicative of incorrect size. Neck length measured by the vertical distance from center of head to superior aspect greater trochanter was zero. A range of +/− 5 mm was acceptable. Neck shaft angle with a difference of >5 degrees was indicative of varus position of the stem. Canals of the proximal femoral categorized as a) stove pipe b) champagne c) fluted varieties radiologically. X-ray magnification corrected. All measurements were done on immediate postoperative radiographs. Stability of various design features of straight stemmed and curved implants are dependant on the anterior bowing angle and canal ratio of femur to prosthesis. A prospective study with CT from selected shapes of the proximal femoral is being carried out. Inappropriate head size as reported by Thompson or neck length was related to incidence of dislocation resulting in failure. Our findings emphasise importance of careful selection of a particular implant design towards the morphology of the femoral canal

Aims

This aim of this study was to assess the reliability and validity of the Unified Classification System (UCS) for postoperative periprosthetic femoral fractures (PFFs) around cemented polished taper-slip (PTS) stems.

Background: The Wrightington Frusto-Conical 2 (FC2) hip is a tapered stem with derotation flutes designed to withstand physiological loads in normal gait. There is a paucity of literature with regard to the outcome of this stem. This study was designed to determine the medium term outcome of the FC2 hip. Methods: We identified 217 consecutive patients who underwent total hip arthroplasty using the FC2 stem in one institution. Patients were recalled for clinical review. Pain, function and movement were assessed using the Harris Hip Score (HHS) and the D’Aubigne Postel Score. General quality of life and hip specific assessed were made using the WOMAC and SF-36 self directed questionnaires. Statistical analysis was performed. Results: 86 patients were assessed with a mean follow-up of 7.3 years. Objective clinical outcomes were judged to be good or excellent according to the HHS and the D’Aubigne Postel scores. WOMAC assessment of disease specific outcome demonstrated excellent results particularly in relation to pain and stiffness. SF-36 demonstrated a quality of life score in keeping with an aging study population. There was a 95% survival at 7.3 years. Conclusions: The FC2 hip has demonstrated a good outcome in the medium term. It shows outcomes that are similar to the Exeter and Charnley hips at this length of followup. Longitudinal follow-up studies are necessary to determine the results of hip implants

Modular hip designs offer potential for customising the implant to the patient. However, the more features a device has to offer, the potential for misuse increases. This paper will review one modular stem and the pearls learned over the years to make this a simple and reproducible surgical technique. Over a 1,000 primary THA have been performed since the development of the proximal modular stem in 2000. The two senior surgeons developed the stem design and surgical techniques used and described here. Two additional surgeon co-authors have used the device as described confirming the design and techniques to be simple, reliable and reproducible. Often the tricks of the trade go unpublished and each new surgeon is left to his own learning curve with new devices. As with any surgical instrumentation there are significant little techniques that often make surgery more reproducible and enjoyable. Surgical technique should be simple and reproducible. We have found that even simple procedures—such as head resection—can, and do, impact the surgical process and can affect surgical outcome. Canal reaming, flute engagement, conical reaming, broaching, trochanter clearance, proper use of modular trials and implant assembly all play critical roles to a successful outcome. We have found, and previously reported, that the use of this proximal modular stem design has reduced our leg length inequalities +/− 5 mm and has all but eliminated dislocations and aseptic loosening. There were some mechanical failure problems (previously reported) on the first generation modular junction design that was identified and corrected (never exported outside the U.S.). There have been no reported failures since introduction of the improved modular junction six years ago. Independent selection of femoral offset and vertical height is possible and we feel that restoration of joint mechanics is more reproducible with proximal modular devices as compared to monoblock stems. It is the responsibility of surgeons to communicate their understanding and experience with newer devices and not rely on industry to fill this function

We studied the various drill bits available for engineering purposes, and compared them with standard orthopaedic drill bits, using continuous temperature recording at 0.5 mm, 1.0 mm and 1.5 mm from the edge of a 2.5 mm hole as it was drilled in fresh cadaver human tibia. We found that some commercially available drill bits performed better than their orthopaedic equivalents, producing significantly less thermal injury to the surrounding bone and halving the force required for cortical penetration. Our work suggests that the optimal bit for orthopaedic purposes should have a split point and a quick helix. Theoretical knowledge of cutting technology predicts that the addition of a parabolic flute will further reduce thermal damage. Further work is being done on other drill sizes used in orthopaedic practice and on new custom-designed bits

Aims

We aimed to report the mid- to long-term rates of septic and aseptic failure after two-stage revision surgery for periprosthetic joint infection (PJI) following total hip arthroplasty (THA).

The unacceptable failure rate of cemented femoral revisions led to many different cementless femoral designs employing fixation in the damaged proximal femur with biological coatings limited to this area. The results of these devices were uniformly poor and were abandoned for the most part by the mid 1990's. Fully porous coated devices employing distal fixation in the diaphysis emerged as the gold standard for revisions with several authors reporting greater than 90% success rate at 8–10 years of follow-up. Surgical techniques and ease of insertion improved with the introduction of the extended trochanteric osteotomy as well as curved, long, fully porous coated stems with diameters up to 23 mm. The limits of these stems were stretched to include any stem diameter in which even 1–2 cm of diaphyseal contact could be achieved. When diaphyseal fixation was not possible (Type IV), the alternatives were either impaction grafting or allograft prosthetic composite (APC). As the results of fully porous coated stems were very carefully scrutinised, it became apparent that certain types of bone loss did not yield the most satisfactory results both clinically and radiographically. When less than 4 cm of diaphyseal press fit (Type IIIB) was achieved, mechanical failure rate (MFR) was over 25%. It also became apparent that even when there was 4–6 cm. diaphyseal contact (Type IIIA), and the stem diameter was 18 mm or greater, post-op pain and function scores were significantly less than those with smaller diameter stems. This was probably due to poorer quality bone. Many of these Type IIIA and Type IIIB femurs had severe proximal torsional remodeling leading to marked distortion of anteversion. This made judging the amount of anteversion to apply to the stem at the time of insertion very difficult, leading to higher rates of dislocation. These distortions were not present in Type I and Type II femurs. This chain of events which was a combination of minimal diaphyseal fixation, excessively stiff stems and higher dislocation rates led to the conversion to modular type stems when these conditions existed. For the past 8 years, low modulus taper stems of the Wagner design have been used for almost all Type IIIA and Type IIIB bone defects. The taper design with fluted splines allows for fixation when there is less than 2 cm of diaphysis. The results in these femurs even with diameters of up to 26 mm have led to very low M.F.R.'s and significantly less thigh pain. Independent anteversion adjustment is also a hug advantage in these modular stems. Similar success rates, albeit with less follow-up, have been noted in Type IV femurs

Aims

There is a paucity of long-term studies analyzing risk factors for failure after single-stage revision for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). We report the mid- to long-term septic and non-septic failure rate of single-stage revision for PJI after THA.

Introduction:. Extensive bone defects of the proximal femur e.g. due to aseptic loosening might require the implantation of megaprostheses. In the literature high loosening rates of such megaprostheses have been reported. However, different fixation methods have been developed to achieve adequate implant stability, which is reflected by differing design characteristics of the commonly used implants. Yet, a biomechanical comparison of these designs has not been reported. The aim of our study was to analyse potential differences in the biomechanical behaviour of three megaprostheses with different designs by measuring the primary rotational stability in vitro. Methods:. Four different stem designs [Group A: Megasystem-C® (Link), Group B: MUTARS®(Implantcast), Group C: GMRS™ (Stryker) and Group D: Segmental System (Zimmer); see Fig. 1] were implanted into 16 Sawbones® after generating a segmental AAOS Typ 2 defect. Using an established method to analyse the rotational stability, a cyclic axial torque of ± 7.0 Nm along the longitudinal stem axis was applied. Micromotions were measured at defined levels of the bone and the implant [Fig. 2]. The calculation of relative micromotions at the bone-implant interface allowed classifying the rotational implant stability. Results:. All four different implants exhibited low micromotions, indicating adequate primary stability. Lowest micromotions for all designs were located near the femoral isthmus [Fig. 3]. The extent of primary stability and the global implant fixation pattern differed considerably and could be related to the different design concepts. Discussion:. Compared to other implant designs, all stems resulted in low relative motions regardless their design. The conical Megasystem-C® stem seems to lock in the proximal isthmus of the femur, whereas the MUTARS® stem seems to have a total fixation. Its hexagonal cross-section might have a good interlocking effect against rotational force application. Similarly, the GMRS™ stem shows a total fixation with little tendency to the distal part. The very rough porous-coated surface seems to generate a comparable fixation method to the hexagonal MUTARS® stem. However, the four longitudinal expansions in the proximal part of the GMRS™ stem might not have such a high rotational stability effect as expected. Compared to the other stems, the Segmental System stem showed very low relative micromotions in the proximal part. This sharp fluted stem seems to engrave itself into the bone. Within this study all stems seemed to achieve an adequate primary rotational stability. We could show that stem design could qualitatively and quantitatively influence the initial fixation behavior of megaprostheses regarding biomechanical tests, like primary stability measurements in synthetic femurs. These experiences should be considered regarding the choice of stem fixation design in specific defect situations