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Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 25 - 25
19 Aug 2024
MacDonald SJ Lanting B Marsh J Somerville L Zomar B Vasarhelyi E Howard JL McCalden RW Naudie D
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The increased demand for total hip arthroplasty (THA) is having a significant impact on healthcare resources, resulting in increased interest in outpatient care pathways to reduce resource consumption. This study compared costs between patients who underwent outpatient THA using a Direct Anterior (DA) approach compared to a Direct Lateral (DL) approach to understand the effect of surgical approach on resource use.

We conducted a prospective randomized controlled trial for DA patients undergoing primary THA. We compared patients in the outpatient arm of the trial to a prospective cohort of outpatient DL approach THAs. We recorded all costs including: equipment, length of stay in hospital, and laboratory or other medical tests. Following discharge, participants also completed a self-reported cost diary recording resource utilization such as emergency department visits or subsequent hospitalizations, tests and procedures, consultations or follow-up, healthcare professional services, rehabilitation, use of pain medications, informal care, productivity losses and out of pocket expenditures.

We report costs from both Canadian public health care payer (HCP) and a societal perspective. The HCP perspective includes any direct health costs covered by the publicly funded system. In addition to the health care system costs, the societal perspective also includes additional costs to the patient (e.g. physiotherapy, medication, or assistive devices), as well as any indirect costs such as time off paid employment for patients or caregivers.

We included 127 patients in the DA group (66.6 years old) and 51 patients in the DL group (59.4 years old) (p<0.01).

There were no statistically significant differences in costs between groups from both the healthcare payer (DA= 7910.19, DL= 7847.17, p=0.80) and societal perspectives (DA= 14657.21, DL= 14581.21, p=0.96)

In patients undergoing a successful outpatient hip replacement, surgical approach does not have an effect on cost from in hospital or societal perspectives.


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 56 - 56
19 Aug 2024
McCalden RW Vasarhelyi EM Howard JL Lanting BA Naudie DD MacDonald SJ
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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.


Bone & Joint Open
Vol. 1, Issue 10 | Pages 653 - 662
20 Oct 2020
Rahman L Ibrahim MS Somerville L Teeter MG Naudie DD McCalden RW

Aims

To compare the in vivo long-term fixation achieved by two acetabular components with different porous ingrowth surfaces using radiostereometric analysis (RSA).

Methods

This was a minimum ten-year follow-up of a prospective randomized trial of 62 hips with two different porous ingrowth acetabular components. RSA exams had previously been acquired through two years of follow-up. Patients returned for RSA examination at a minimum of ten years. In addition, radiological appearance of these acetabular components was analyzed, and patient-reported outcome measures (PROMs) obtained.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_12 | Pages 9 - 9
1 Oct 2019
Wood T Ndoja S Howard JL McCalden RW Lanting BA Naudie DDR
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Introduction

Trunnion wear has been reported as a cause for failure of modern total hip replacement implants. While there are several reports on the prevalence of trunnion corrosion with specific stem designs, little is known about the prevalence of this problem across other femoral stem designs. The purpose of this study is to review three commonly used uncemented femoral stems and to correlate any established risk factors with rates of revision.

Methods

We reviewed all patients followed prospectively over a 15-year period (March 2000 to September 2015) who underwent total hip arthroplasty with one of three modern uncemented femoral stem designs. All of the stems were made of titanium (Ti6Al4V alloy) with a 12/14 taper design. We included only metal (cobalt chromium) on highly cross-linked polyethylene articulations. We evaluated age, gender, body mass index (BMI), femoral head size, head length, neck angle and offset as potential risk factors for all cause revision and revision excluding infection by univariate analysis. We performed a logistic regression analysis with odds ratios (OR) for each parameter for both all cause revision as well as with infection excluded. We used a p value of <0.05 as a level of significance.


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_12 | Pages 64 - 64
1 Oct 2019
McCalden RW Decker MM Klassen RJ Lanting B
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Introduction

HXLPE acetabular liners were introduced to reduce wear-related complications in THA. However, post-irradiation thermal free radical stabilization can compromise mechanical properties, leave oxidation-prone residual free radicals, or both. Reports of mechanical failure of HXLPE acetabular liner rims raise concerns about thermal free radical stabilization and in vivo oxidization on implant properties. The purpose of this study is to explore the differences in the mechanical, physical and chemical properties of HXLPE acetabular liner rims after extended time in vivo between liners manufactured with different thermal free radical stabilization techniques.

Material and methods

Remelted, single annealed and sequentially annealed retrieved HXLPE acetabular liners with in vivo times greater than 4.5 years were obtained from our implant retrieval laboratory. All retrieved liners underwent an identical sanitation and storage protocol. For mechanical testing, a total of 55 explants and 13 control liners were tested. Explant in vivo time ranged from 4.6 – 14.0 years and ex vivo time ranged from 0 – 11.6 years. Rim mechanical properties were tested by microindentation hardness testing using a Micromet II Vickers microhardness tester following ASTM standards. A subset of 16 explants with ex vivo time under one year along with five control liners were assessed for oxidation by FTIR, crystallinity by Raman spectroscopy, and evidence of microcracking by SEM.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_13 | Pages 35 - 35
1 Oct 2018
MacDonald SJ Garach M Lanting B McCalden RW Vasarhelyi E Naudie D Howard J
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Introduction

The infection rate after total joint arthroplasty (TJA) has been shown to be 1–2% in multiple series and registry data. Irrigation, debridement, and polyethylene exchange (IDPE) is a common first line treatment in many cases of acute prosthetic joint infection (PJI). The reinfection rate in open IDPE procedures is variable with studies showing reinfection rates of 10–70% depending on various patient and microbial factors. Our pilot study aimed to determine if the bacterial load in infected total joints was sufficiently reduced by IDPE to allow for the use of post-debridement cultures as an independent marker of procedural success.

Methods

46 prosthetic joint infections underwent irrigation and debridement using 6L of normal saline and 3L of a normal saline and bacitracin mixture prior to the insertion of a new polyethylene liner. This protocol utilized a single equipment setup with all surgical members donning new gloves prior to polyethylene exchange. Between 3 and 5 intraoperative cultures were obtained both prior to and after debridement as per the surgeon's standard protocol. A two-tailed student's t-test was used to evaluate for any differences in the rate of positive culture between these two groups.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_13 | Pages 26 - 26
1 Oct 2018
McCalden RW Ponnusamy K Vasarhelyi EM Somerville LE Howard JL MacDonald SJ Naudie DD Marsh JD
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Introduction

The purpose of this study is to estimate the cost-effectiveness of performing total hip arthroplasty (THA) versus nonoperative management (NM) in non-obese (BMI 18.5–24.9), overweight (25–29.9), obese (30–34.9), severely-obese (35–39.9), morbidly-obese (40–49.9), and super-obese (50+) patients.

Methods

We constructed a state-transition Markov model to compare the cost-utility of THA and NM in the six above-mentioned BMI groups over a 15-year time period. Model parameters for transition probability (i.e. risk of revision, re-revision, death), utility, and costs (inflation adjusted to 2017 US dollars) were estimated from the literature. Direct medical costs of managing hip arthritis were accounted in the model. Indirect societal costs were not included. A 3% annual discount rate was used for costs and utilities. The primary outcome was the incremental cost-effectiveness ratio (ICER) of THA versus NM. One-way and Monte Carlo probabilistic sensitivity analysis of the model parameters were performed to determine the robustness of the model.


The Bone & Joint Journal
Vol. 100-B, Issue 7 | Pages 891 - 897
1 Jul 2018
Teeter MG Lanting BA Naudie DD McCalden RW Howard JL MacDonald SJ

Aims

The aim of this study was to determine whether there is a difference in the rate of wear between acetabular components positioned within and outside the ‘safe zones’ of anteversion and inclination angle.

Patients and Methods

We reviewed 100 hips in 94 patients who had undergone primary total hip arthroplasty (THA) at least ten years previously. Patients all had the same type of acetabular component with a bearing couple which consisted of a 28 mm cobalt-chromium head on a highly crosslinked polyethylene (HXLPE) liner. A supine radiostereometric analysis (RSA) examination was carried out which acquired anteroposterior (AP) and lateral paired images. Acetabular component anteversion and inclination angles were measured as well as total femoral head penetration, which was divided by the length of implantation to determine the rate of polyethylene wear.


The Bone & Joint Journal
Vol. 98-B, Issue 1 | Pages 28 - 32
1 Jan 2016
Hanna SA Somerville L McCalden RW Naudie DD MacDonald SJ

Aims

The purpose of this study was to compare the long-term results of primary total hip arthroplasty (THA) in young patients using either a conventional (CPE) or a highly cross-linked (HXLPE) polyethylene liner in terms of functional outcome, incidence of osteolysis, radiological wear and rate of revision.

Methods

We included all patients between the ages of 45 and 65 years who, between January 2000 and December 2001, had undergone a primary THA for osteoarthritis at our hospital using a CPE or HXLPE acetabular liner and a 28 mm cobalt-chrome femoral head.

From a total of 160 patients, 158 (177 hips) were available for review (CPE 89; XLPE 88). The mean age, body mass index (BMI) and follow-up in each group were: CPE: 56.8 years (46 to 65); 30.7 kg/m2 (19 to 58); 13.2 years (2.1 to 14.7) and HXLPE: 55.6 years (45 to 65); BMI: 30 kg/m2 (18 to 51); 13.1 years (5.7 to 14.4).


The Bone & Joint Journal
Vol. 97-B, Issue 5 | Pages 595 - 602
1 May 2015
McCalden RW Korczak A Somerville L Yuan X Naudie DD

This was a randomised controlled trial studying the safety of a new short metaphyseal fixation (SMF) stem. We hypothesised that it would have similar early clinical results and micromovement to those of a standard-length tapered Synergy metaphyseal fixation stem. Using radiostereometric analysis (RSA) we compared the two stems in 43 patients. A short metaphyseal fixation stem was used in 22 patients and a Synergy stem in 21 patients. No difference was found in the clinical outcomes pre- or post-operatively between groups. RSA showed no significant differences two years post-operatively in mean micromovement between the two stems (except for varus/valgus tilt at p = 0.05) (subsidence 0.94 mm (sd 1.71) vs 0.32 mm (sd 0.45), p = 0.66; rotation 0.96° (sd 1.49) vs 1.41° (sd 2.95), p = 0.88; and total migration 1.09 mm (sd 1.74) vs 0.73 mm (sd 0.72), p = 0.51). A few stems (four SMF and three Synergy) had initial migration > 1.0 mm but stabilised by three to six months, with the exception of one SMF stem which required revision three years post-operatively. For most stems, total micromovement was very low at two years (subsidence < 0.5 mm, rotation < 1.0°, total migration < 0.5 mm), which was consistent with osseous ingrowth. The small sample makes it difficult to confirm the universal applicability of or elucidate the potential contraindications to the use of this particular new design of stem.

Cite this article: Bone Joint J 2015; 97-B:595–602.


The Journal of Bone & Joint Surgery British Volume
Vol. 93-B, Issue 3 | Pages 321 - 325
1 Mar 2011
McCalden RW Charron KD MacDonald SJ Bourne RB Naudie DD

We evaluated the outcome of primary total hip replacement (THR) in 3290 patients with the primary diagnosis of osteoarthritis at a minimum follow-up of two years. They were stratified into categories of body mass index (BMI) based on the World Health Organisation classification of obesity. Statistical analysis was carried out to determine if there was a difference in the post-operative Western Ontario and McMaster Universities osteoarthritis index, the Harris hip score and the Short-Form-12 outcome based on the BMI.

While the pre- and post-operative scores were lower for the group classified as morbidly obese, the overall change in outcome scores suggested an equal if not greater improvement compared with the non-morbidly obese patients. The overall survivorship and rate of complications were similar in the BMI groups although there was a slightly higher rate of revision for sepsis in the morbidly obese group.

Morbid obesity does not affect the post-operative outcome after THR, with the possible exception of a marginally increased rate of infection. Therefore withholding surgery based on the BMI is not justified.


The Journal of Bone & Joint Surgery British Volume
Vol. 92-B, Issue 7 | Pages 935 - 940
1 Jul 2010
McCalden RW Charron KD Yuan X Bourne RB Naudie DD MacDonald SJ

This was a safety study where the hypothesis was that the newer-design CPCS femoral stem would demonstrate similar early clinical results and micromovement to the well-established Exeter stem. Both are collarless, tapered, polished cemented stems, the only difference being a slight lateral to medial taper with the CPCS stem. A total of 34 patients were enrolled in a single-blinded randomised controlled trial in which 17 patients received a dedicated radiostereometric CPCS stem and 17 a radiostereometric Exeter stem. No difference was found in any of the outcome measures pre-operatively or post-operatively between groups. At two years, the mean subsidence for the CPCS stem was nearly half that seen for the Exeter stem (0.77 mm (−0.943 to 1.77) and 1.25 mm (0.719 to 1.625), respectively; p = 0.032). In contrast, the mean internal rotation of the CPCS stem was approximately twice that of the Exeter (1.61° (−1.07° to 4.33°) and 0.59° (0.97° to 1.64°), respectively; p = 0.048). Other migration patterns were not significantly different between the stems. The subtle differences in designs may explain the different patterns of migration.

Comparable migration with the Exeter stem suggests that the CPCS design will perform well in the long term.


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 10 | Pages 1333 - 1336
1 Oct 2005
Busch CA Charles MN Haydon CM Bourne RB Rorabeck CH MacDonald SJ McCalden RW

We identified five (2.3%) fractures of the stem in a series of 219 revision procedures using a cementless, cylindrical, extensively porous-coated, distally-fixed femoral stem. Factors relating to the patients, the implant and the operations were compared with those with intact stems. Finite-element analysis was performed on two of the fractured implants.

Factors associated with fracture of the stem were poor proximal bone support (type III–type IV; p = 0.001), a body mass index > 30; (p = 0.014), a smaller diameter of stem (< 13.5 mm; p = 0.007) and the use of an extended trochanteric osteotomy (ETO 4/5: p = 0.028). Finite-element analysis showed that the highest stresses on the stem occurred adjacent to the site of the fracture. The use of a strut graft wired over an extended trochanteric osteotomy in patients lacking proximal femoral cortical support decreased the stresses on the stem by 48%.

We recommend the use of a strut allograft in conjunction with an extended trochanteric osteotomy in patients with poor proximal femoral bone stock.