Studies have reported stem subsidence without loosening in cemented polished tapered stems. And also, the initial radiolucency seen immediately after surgery at the bone-cement interface has decreased in some cases with polished tapered stem as time passed. The etiologies of these phenomena are not still elucidated. We made a comparative study on the relation between stem subsidence and the initial radiolucency in polished and rough surface stems. Subjects were 42 hips of 38 cases and 36 hips of 31 cases received primary THA using a Collarless Polished
Aim of this study was to identify reoperation rates in patients with short oblique and transverse fractures around a well fixed cemented polished taper slip stem and to determine any associations with treatment failure. Retrospective cohort study of 31 patients with AO transverse or short oblique Vancouver B1 PFFs around THA (total hip arthroplasty) cemented taper slip stems: 12 male (39%); mean age 74±11.9 (range 44–91); mean BMI 28.5±1.4 (range 16–48); and median ASA 3. Patient journeys were assessed, re-interventions reviewed. The primary outcome measure was reoperation. Time from primary THA to fracture was 11.3±7.8yrs (0.5–26yrs). Primary surgical management was fixation in 27/31 and rTHA (revision total hip arthroplasty) in 4/31. 10 of 31 (32%) patients required reoperation, 9 within 2 years of fracture: 1 following rTHA and 8 following ORIF. The commonest mode of failure was non-union (n=6). No significant associations with reoperation requirement were identified. Kaplan-Meier free from reoperation was 67.4% (49.8–85.0 95% CI) at 2 years and this was unaffected by initial management with ORIF or rTHA (Log rank 0.898). Of those reoperated, 6/10 required multiple reoperations to obtain either bony union or a stable revision construct and 13% ultimately required proximal femoral endoprostheses. The relative risk of 1 year mortality was 1.6 (0.25 to 10.1 95%CI) among patients who required reoperation compared to those who did not. These are difficult fractures to manage, should not be underestimated and patients should be counselled that there is a 30% risk of reoperation and 20% of requiring multiple reoperations.
The aim of the study was to report the survival of open reduction and internal fixation (ORIF) of Vancouver B fractures associated with the Exeter Stem (ES) at a minimum of 5 years. This retrospective cohort study assessed 129 consecutive patients with Vancouver B type fractures treated with ORIF from 2008-2016 at a minimum of 5 years. Patient records were examined, and the following recorded: details of primary prosthesis, details of injury, Vancouver classification, details of operative management, complications, and requirement for reoperation. Data was analysed using SPSS. Survival analysis was undertaken using the endpoint ‘reoperation for any reason’. Mean age at fracture was 78.2 (SD10.6, 46-96) and 54 (43%) were female. Vancouver subclassifications were: 24% B1, 70.5% B2 and 5.5% B3. For all Vancouver B fractures, Kaplan Meier analysis demonstrated a 5 year survival free from reoperation of 88.8% (82.0-94.7 95%CI). Fourteen patients required reoperation, most commonly within the first year for non-union and plate fracture (5.4%). Five-year survival for any reoperation differed significantly according to fracture type (p=0.016) and was worst in B1s: B1 76.6% (61.3-91.9); B2 92.6% 986.9-98.3); and 100% of B3. Univariate analysis identified B1 type (p=0.008) and a transverse fracture pattern (p=0.003) to be significantly associated with the need for reoperation. Adopting a strategy of fixation of all Vancouver B fractures involving the ES where the fracture was anatomically reducible and the bone cement interface was well-fixed was associated with a 5 year survival, free from reoperation of 88.8%.
The use of monoblock tapered stems has shown very good results in hip revision surgery, particularly in case of severe proximal femur bone deficiency. However a too valgus neck, a short offset, may result in a high risk of dislocation. In addiction monoblock stems make the control of limb length difficult, and potentially increase the risk of subsidence or intraoperative fracture. Different types of modular tapered stems with distal fixation have been developed to allow a more user-friendly restoration of limb-lenght discrepancy and an indipendent proximal control of offset and anti-retroversion. We assessed 64 hip revisions performed on 63 patients (mean age 62 years). Indication for treatment was: aseptic loosening (42 cases) septic loosening (18 cases) and periprosthetic fracture (4 cases). According to Paprosky classification, femoral defects were staged as type I (2 cases), type II (20 cases), type IIIA (25 cases) and type IIIB (13 cases); periprosthetic fractures were all type B2 according to the Vancouver classification. In all cases we used a Restoration® Modular (Striker, Orthopaedics) cone-conical uncemented stem implanted by a lateral approach, with a trans-femoral osteotomy in 19 cases. A preventive cerclage cable was used in 10 patients in case of very thin cortex. We used the minimum size stem in most of the cases. Mean follow-up was 20 months (range 6–36). Short-term complications included hip dislocation (1 case), recurrent infection (1 case), stem subsidence >
5 mm (1 case). Mean Harris Hip Score improved from 43 to 81.9 (t test p<
0.0005), while limb lenght discrepancy improved in 97% of cases with symmetry in 76%. The use of modular revision stems is an effective alternative in hip revision surgery that ensures good primary stability, while modularity enables the implant to be tailored to the patient, allowing restoration of the limb length and correct muscular balancing.
Modular tapered stems have become increasingly popular in femoral revisions and stem subsidence remains a reported clinical problem. Computer modeling and biomechanical testing demonstrated a minimum initial line-to-line fit of 25 mm was required to reduce the risk of subsidence. We examined XR imaging of 110 consecutive femoral revisions by a single surgeon using two different modular tapered stems to determine if this biomechanical threshold was of clinical relevance. 72% of the revisions were done for aseptic loosening and 28% for periprosthetic fracture or infection. Stem subsidence of any degree was observed in 24 (21.8%), while 12 (10.9%) demonstrated substantial subsidence of > 10 mm. We matched this cohort to 12 patients who had no stem subsidence. The average age of patients with subsidence was 59 years (43 to 79 years). The average of patients without subsidence was 66 years (41 to 77 years). Each group had 7 men and 5 women. Stem subsidence was observed in the first 3 months post-surgery. The demographics, bone deficiency, stem design, and stem diameter were similar between groups. 83% of patients with substantial stem subsidence had less than 25 mm of line-to-line fit compared to 17% of patients without subsidence. The 12 cases of no stem subsidence had a mean line-to-line fit of 48 mm (25 to 55 mm). 75% of patients with substantial stem subsidence had also undergone an extended trochanteric osteotomy (ETO) compared to 33% of patients without subsidence. We conclude that there is a positive correlation with the biomechanical testing parameters and substantial stem subsidence. ETO was found to be associated with higher stem subsidence.
While the short-stem design is not a new concept, interest has risen with increasing utilization of less invasive techniques. Especially, short stems are easier to insert through the direct anterior approach. In the radiographic evaluation of patients who underwent primary uncemented total hip arthroplasty (THA) using a TaperLoc Microplasty femoral component (Biomet, Warsaw, IN, USA), cortical hypertrophy was occasionally detected on three-month postoperative radiographs. The purpose of this study was to evaluate the radiographic changes associated with cortical hypertrophy of the femur three months postoperatively. Between May 2010 and September 2014, 645 hips in 519 patients who received the TaperLoc Microplasty stem were evaluated. Six hips in four patients were lost to follow-up. Finally, 639 hips in 515 patients were included in this study; 248 hips underwent bilateral simultaneous THA and 391 hips underwent unilateral THA. There were 103 males and 412 females (average age, 63 ± 10.1 years; average height, 156 ± 8.13 cm; and average weight, 58 ± 12.2 kg). The postoperative radiographs immediately taken after the operation and three months postoperatively were compared. We evaluated cortical hypertrophy around the stem. Cortical hypertrophy >2 mm on anterior-posterior X-ray was defined as “excessive periosteal reaction” (Figure 1).Objective
Methods
The aim of this study is 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). This is a retrospective cohort study of 152 operatively managed consecutive unilateral Vancouver B fractures involving Exeter stems. 130 were managed with open reduction and internal fixation (ORIF) and 22 with revision arthroplasty. Radiographs were assessed and classified by 3 observers. The primary outcome measure was revision of ≥1 component. Kaplan Meier survival analysis was performed. Logistic regression was used to identify risk factors for revision following ORIF. Secondary outcomes included any reoperation, complications, blood transfusion, length of hospital stay and mortality. Fractures (B1 n=74 (49%); B2 n=50 (33%); and B3 n=28 (18%)) occurred at mean 6.7±10.4 years after primary THA (n=143) or hemiarthroplasty (n=15). Mean follow up was 6.5 ±2.6 years (3.2 to 12.1). Rates of revision and reoperation were significantly higher following revision arthroplasty compared to ORIF for B2 (p=0.001) fractures and B3 fractures (p=0.05). Five-year survival was significantly better following ORIF: 92% (86.4 to 97.4 95%CI) Vs 63% (41.7 to 83.3), p<0.001. No independent predictors of revision following ORIF were identified: fixation of B2 or B3 fractures was not associated with an increased risk of revision. Dislocation was the commonest mode of failure after revision arthroplasty. ORIF was associated with reduced blood transfusion requirement and reoperations, but there were no differences in medical complications, hospital stay or mortality between surgical groups. When the bone-cement interface was intact and the fracture was anatomically reducible, Vancouver B2 fractures around Exeter stems can be treated with fixation as opposed to revision arthroplasty. Fixation of Vancouver B3 fractures can be performed in frail elderly patients without increasing revision risk.
Proximally-coated non-cemented tapered femoral stems have demonstrated excellent long-term clinical results. However, there is sparse literature reporting the incidence of failure of osteointegration in patients with this stem design. The aim of this study is to report this incidence and identify factors which may increase its risk. 206 elective primary total hip arthroplasties were performed consecutively with a single stem design over a three-year period. All patients were evaluated clinically and radiographically. Radiographic parameters were analyzed for any potential risk factors that may predispose to failure of osteointegration. Three of 206 hips failed to osteointegrate and subsequently underwent revision surgery, for an incidence of 1.5%. The average time to revision was 1.2 years. The presenting complaint was persistent pain and radiographs revealed a progressive linear lucency at the proximal implant-bone interface in all three patients. Each patient had been implanted with a large-sized stem that had achieved a diaphyseal fit radiographically. This cohort had a statistically lower canal-flare index (p <
0.05) when compared to the rest of the study group. At the time of surgery, all stems were found to be loose and were easily removed. Failure of osteointegration in this type of stem is an uncommon but serious complication that may necessitate revision surgery. Risk factors predisposing to a failure to osteointegrate are a mismatch between the patient’s proximal femoral geometry and the stem, specifically a large stem in a Dorr type C femur, leading to a diaphyseal rather than a metaphyseal wedge.
Recently, short shaped stem becomes popular in total hip arthroplasty (THA). Advantages of the short stem are preserving femoral bone stock, thought to be less thigh pain, suitable for minimally invasive THA. However, bony reaction around the short stem has not been well known. The purpose of this study was to compare the two years difference of radiographic change around the standard tapered round stem with the shorter tapered round stem. Evaluation was performed in 96 patients (100 joints) who underwent primary THA. Standard tapered round stem (Bicontact D stem) was used in 44 patients from January 2011 to May 2013. Shorter stem (Bicontact E stem) was used in 56 patients from May 2015 to March 2016. The proximal shapes of these two stems are almost the same curvature. The mean age at surgery was 64 years. The mean BMI at surgery was 24.0 kg/m2. Eighty-six patients had osteoarthrosis and 10 patients had osteonecrosis. Evaluation was performed 2 years after surgery with standard AP radiographs. The OrthoPilot imageless navigation system was used during surgery. Evaluation of the stem fixation, stress shielding, and cortical hypertrophy were carried out.INTRODUCTION
MATERIALS AND METHODS
Femoral impaction grafting with cancellous bone and cement is an important technique in reconstituting deficient bone stock in revision hip arthroplasty. We report the medium to long term results of 75 consecutive patients using a collarless, polished, tapered femoral stem with an average age of 68 (±11.4) years and a mean follow up of 10.5 (±2.4) years (range 6.3 to 14.1 years). The median Endoklinik pre-operative bone defect score was 3 (IQR: 2–3) with a median subsidence at 1 year of 2mm (IQR: 1–3mm). At the most recent follow-up (mean 10.5±2.4 years), the median Harris Hip Score (HHS) was 80.6 (IQR: 67.6–88.9) and median subsidence 2mm (IQR: 1–4mm). Ten-year survivorship with any further femoral operation as an endpoint was 92%. Four prostheses required further revision. Subsidence of the Exeter stem continued, albeit at a slower rate after the first year and was related to the Endoklinik pre-operative bone loss (p=0.037). The degree of subsidence at 1 year was a strong predictor of long term subsidence (p<0.001). Neither subsidence nor bone stock were related to long term outcome (HHS). There was a correlation between previous revision surgery and a poor Harris Hip Score (p=0.028) and those who had undergone previous revision surgery for infection had a higher risk of complications (p=0.048). The good long term results of this technique commend its use in revision hip arthroplasty for patients with poor femoral bone stock.
Corrosion of modular tapers is increasingly recognized as a source of adverse tissue reaction (ALTR) and revision surgery in total hip arthroplasty (THA). The incidence of corrosion and rate of revision for ALTR may differ among different types of implants. The objective of this study was to determine if a difference exists in rate of THA revision for corrosion and ALTR with tapered broach only stems compared to ream-broach femoral stems.INTRODUCTION
OBJECTIVE
A multicentre prospective study in the USA involves more than 75 investigators who have enrolled over 1 800 cases over nearly four years. In a subset of this group, the performance of a tapered, cementless, porous stem is being evaluated. One surgeon has used this stem in 301 hips in 282 patients, of whom 141 are at one-year follow-up and 51 at two-year follow-up. An optional large proximal body stem was often used to optimise proximal femoral fill. Clinical and radiological examinations were carried out immediately after surgery and at 6, 12 and 24 months, and demographic, Health Status (SF-12), and Harris Hip Score (HSS) data noted. From a preoperative mean of 41, the HSS improved to 88 and 92 at one-year and two-year follow-ups respectively. No progressive radiolucency, implant migration, gross loosening, osteolysis or polyethylene wear has been observed.
The median follow-up time was 6 (5–11) years. The median VAS for pain for the affected hip was 0 (0–5) at rest and 0 (0–9) at movement. The median HHS at follow-up was 78 (16–100) points. 17 (19%) patients dislocated their hips during follow-up. A prosthesis head size of 22 mm was present in 6/17 (35%) patients with dislocation and in 11/73 (15%) patients without dislocation (P = 0.055). The cumulative 5 year survival rate was 98% (95% CI: 94–100%) with stem removal and 90% (95% CI: 85–96%) with any reoperation as the endpoint. At follow-up, we noted subjectively that 17% of the cases had evidence of proximal bone restoration, whereas 44% had constant defects. In 39% the quality of the proximal bone appeared to be declining. If present, this was mostly seen around the lesser trochanter. The median vertical stem migration was 2.7 (0–30) mm
We have prospectively followed up 191 consecutive primary total hip replacements utilising a collarless polished tapered (CPT) femoral stem, implanted in 175 patients between November 1992 and November 1995. At a mean follow-up of 15.9 years (range 14 – 17.5) 86 patients (95 hips) were still alive (25 men and 61 women) and available for routine follow up. Clinical outcome was determined from a combination of the Harris (HHS) and Oxford (OHS) hip scores. Radiological assessment was with antero-posterior radiographs of both hips and a lateral radiograph of the operated hip. The radiographs were evaluated using well-recognised assessment techniques. There was no loss to follow up, with clinical data available on all 95 hips. Five patients were too frail to undergo radiographic assessment, therefore radiological assessment was performed on 90 hips (95%). At the latest follow-up, the mean HHS was 78 (range 28 – 100) and the mean OHS was 36 (range 15 – 48). Stems subsided within the cement mantle, with a mean total subsidence of 2.1mm (range 0.4 – 24). Higher grades of heterotopic bone formation were significantly associated with males (p<0.001) and hypertrophic osteoarthritis (p<0.001). Acetabular wear was associated with increased weight (p<0.001) and male sex (p=0.005). Amongst the cohort, only 1 stem (1.1%) has been revised due to aseptic loosening. This patient required reaming of their canal prior to implantation, as a result of a previous femoral osteotomy. The rate of stem revision for any cause was 7.4% (7 stems), of which 4.2% (4 stems) resulted from infection following revision of the acetabular component. Twenty patients (21.1%) required some sort of revision procedure; all except 3 of these resulted from failure of the acetabular component. Cemented cups had a significantly lower revision burden (2.7%) than Harris Galante uncemented components (21.8%) (p<0.001). The CPT stem continues to provide excellent radiological and clinical outcomes at 15 years following implantation. Its results are consistent with other polished tapered stem designs. Cup failure remains a problem and is related in part to inadequate bearings and biological abnormalities.
Recently, the short stem has become popular in total hip arthroplasty (THA). The advantages of the short stem are that it preserves femoral bone stock, possibly results in less thigh pain, and is suitable for minimally invasive THA. However, because of the short stem, malposition may happen during surgery. The purpose of this study was to compare the stem alignment, which was measured by CT, between the standard tapered round stem and the shorter tapered round stem. CT evaluation was performed in 28 patients (29 joints) who underwent primary THA. The standard tapered round stem (Bicontact D stem) was used in 13 patients. The shorter stem (Bicontact E stem) was used in 16 patients (17 joints). The proximal shapes of these two stems have almost the tame curvature. The mean age at surgery was 68 years. The mean BMI at surgery was 23.3 kg/m2. Eighteen patients had osteoarthrosis, 3 patients had osteonecrosis, and 1 patient had femoral neck fracture. All surgeries were performed in the supine position with the direct anterior approach. The OrthoPilot imageless navigation system was used during surgery. Evaluation of the stem antetorsion angle (AA), flexion angle (FA), and varus angle (VA) were carried out.INTRODUCTION
MATERIALS AND METHODS
23 hips (15.1%) needed revision surgery. The majority (17 hips – 73.9% of all reoperations) were revised due to progressive Polyethylene wear, all after a minimum of ten years. Exchange of the polyethylene inlay and the ceramic head was performed in 14 hips. In two cases the acetabular component and in one case the femoral component were found to be loose intraoperatively because of the wear debris and had to be exchanged. 4 hips had to be revised due to aseptic cup loosening without signs of increased polyethylene wear. There was one revision due to a late deep infection and one because of a periprothetic femoral fracture.
The collarless polished tapered stem (CPT) is a double tapered, cemented femoral component designed for primary hip replacement and as a revision stem for impaction bone grafting. We report outcome at a minimum of 10 years (mean 11 years 1 month). Of 191 consecutive primary hip replacements in 174 patients, implanted using contemporary cementing techniques, 63 patients died before 10 years (68 hips). None of these stems had been revised or had radiological signs of failure at their last follow-up. Only one patient (two hips) was lost to radiological follow-up, hence complete radiological data was available on 121 hips and clinical follow-up on 123 hips. The fate of all the hips is known. Survivorship with revision of the femoral component for aseptic loosening as the endpoint was 100%. The Harris hip scores were good or excellent in 75% of the patients with a mean of 86. All the stems subsided vertically within the cement mantle at a mean rate of 0.18mm per year, stabilising to a mean total of 1.95 mm (0.21–24 mm) after a mean of 11 years 1 month. Unlike Exeter stems there was no change in the alignment of the stems. There was excellent preservation of proximal bone and an extremely low (<
2%) incidence of loosening at the cement bone interface. The study confirms that the CPT subsides within the cement mantle, but without failing. It performs at-least as well as the best stems currently available.
The best type of stem fixation for revision hip arthroplasty is still controversial with regard to medium and long tem results. We wanted to ascertain the medium term results of revision hip arthroplasty using cemented collarless polished tapered femoral stem.