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Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 44 - 44
1 Dec 2022
Turgeon T Bohm E Gascoyne T Hedden D Burnell C
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This study used model-based radiostereometric analysis (MBRSA) to compare migration of a recently introduced cementless hip stem to an established hip stem of similar design. Novel design features of the newer hip stem included a greater thickness of hydroxyapatite coating and a blended compaction extraction femoral broach.

Fifty-seven patients requiring primary total hip arthroplasty (THA) were enrolled at a single centre. Patients were randomized to receive either an Avenir collarless stem and Trilogy IT cup (ZimmerBiomet) or a Corail collarless stem and Pinnacle cup (DePuy Synthes) via a posterior or lateral approach. Both stems are broach-only femoral bone preparation. RSA beads (Halifax Biomedical) were inserted into the proximal femur during surgery. Patients underwent supine RSA imaging a 6 weeks (baseline), 6, 12, and 24 months following surgery. The primary study outcome was total subsidence of the hip stem from baseline to 24 months as well as progression of subsidence between 12 and 24 months. These values were compared against published migration thresholds for well-performing hip stems (0.5mm). The detection limit, or precision, of MBRSA was calculated based on duplicate examinations taken at baseline. Patient reported outcome measures were collected throughout the study and included the Oxford-12 Hip Score (OHS), EuroQoL EQ-5D-5L, Hip Osteoarthritis Score (HOOS) as well as visual analogue scales (VAS) for thigh pain and satisfaction. Analysis comprised of paired and unpaired t-tests with significance set at p≤0.05.

Forty-eight patients (30 males) were included for analysis; 7 patients received a non-study hip stem intra-operatively, 1 patient suffered a traumatic dislocation within three weeks of surgery, and 1 patient died within 12 months post-surgery. RSA data was obtained for 45 patients as three patients did not receive RSA beads intra-operatively. Our patient cohort had a mean age of 65.9 years (±;7.2) at the time of surgery and body mass index of 30.5 kg/m2 (±;5.2). No statistical difference in total stem migration was found between the Avenir and Corail stems at 12 months (p=0.045, 95%CI: −0.046 to 0.088) and 24 months (p=0.936, 95% CI: −0.098 to 0.090). Progression of subsidence from 12-24 months was 0.011mm and 0.034mm for the Avenir and Corail groups which were not statistically different (p=0.163, 95%CI: −0.100 to 0.008) between groups and significantly less than the 0.5mm threshold (pNo statistically significant differences existed between study groups for any pre-operative function scores (p>0.05). All patients showed significant functional improvement from pre- to post-surgery and no outcome measures were different between study groups with exception of EQ-5D-5L health visual analogue scale at 12 months which showed marginally superior (p=0.036) scores in the Avenir group. This study was not powered to detect differences in clinical outcomes.

This study has demonstrated no statistical difference in subsidence or patient-reported outcomes between the Corail hip stem and the more recently introduced Avenir hip stem. This result is predictable as both stems are of a triple-tapered design, are coated with hydroxyapatite, and utilize a broach-only bone preparation technique. Both stem designs demonstrate migration below 0.5mm suggesting both are low-risk for aseptic loosening in the long-term.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_3 | Pages 28 - 28
1 Mar 2021
El-Hawary R Padhye K Howard J Ouellet J Saran N Abraham E Manson N Peterson D Missiuna P Hedden D Alkhalife Y Viswanathan V Parsons D Ferri-de-Barros F Jarvis J Moroz P Parent S Mac-Thiong J Hurry J Orlik B Bailey K Chorney J
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Proximal junctional kyphosis (PJK) is defined as adjacent segment kyphosis >10° between the upper instrumented vertebrae and the vertebrae 2 levels above following scoliosis surgery. There are few studies investigating the predictors and clinical sequelae involved with this relatively common complication. Our purpose was to determine the radiographic predictors of post-op PJK and to examine the association between PJK and pain/HRQOL following surgery for AIS.

The Post-Operative Recovery after Scoliosis Correction: Home Experience (PORSCHE) study was a prospective multicenter cohort of AIS patients undergoing spinal fusion surgery. Pre-op and minimum 2 year f/u scoliosis and sagittal spinopelvic parameters (thoracic kyphosis–TK, lordosis–LL, pelvic tilt-PT, sacral slope-SS, pelvic incidence-PI) were measured and compared to numeric rating scale for pain (NRS) score, SRS-30 HRQOL and to the presence or absence of PJK (proximal junctional angle >100). Continuous and categorical variables were assessed using logistic regression and binomial variables were compared to binomial outcomes using chi-square.

163 (137 females) patients from 8 Canadian centers met inclusion criteria. At final f/u, PJK was present in 27 patients (17%). Pre-op means for PJK vs No PJK: Age 14.1 vs 14.7yr; females 85 vs 86%; scoliosis 57±22 vs 62±15deg; TK 28±18 vs 19±16deg ∗, LL 62±11 vs 60±12deg, PT 8±12 vs 10±10deg, SS 39±8 vs 41±9deg, PI 47±14 vs 52±13deg, SVA −9±30 vs −7±31mm. Final f/u for PJK vs No PJK: Scoliosis 20±11 vs 18±8deg, final TK 26±12 vs 19±10deg∗, LL 60±11 vs 57±12deg, PT 9±12 vs 12±13deg, SS 39±9 vs 41±9deg, PI 48±17 vs 52±14deg, SVA −23±26 vs −9±32mm∗. Significant findings: Pre-op kyphosis >40deg has an odds ratio (OR) of 4.41 (1.50–12.92) for developing PJK∗. The presence of PJK was not associated with any significant differences in NRS or SRS-30. ∗denotes p<0.05.

This prospective multicenter cohort of AIS patients demonstrated a 17% risk of developing PJK. Pre-op thoracic kyphosis >40deg was associated with the development of PJK; however, the presence of PJK was not associated with increased pain or decreased HRQOL.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 2 - 2
1 Feb 2020
Turgeon T Burnell C Hedden D Gascoyne T Bohm E
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Introduction

Total hip arthroplasty (THA) is a highly successful procedure achieving excellent clinical outcomes beyond 10 years post-surgery. With exception of periprosthetic infection, dislocation is the most common cause of failure in THA. A novel reverse total hip (RTH) replacement has been developed to address dislocation through reversal of the typical THA articulation in which a femoral cup and acetabular ball interlock at the extremes of motion to enhance mechanical stability in all planes. The purpose of this study was to assess the safety and efficacy of this novel RTH in a series of 22 patients and to monitor implant fixation using radiostereometric analysis (RSA).

Methods

Twenty two patients with end-stage osteoarthritis of the hip were enrolled between 2017 and 2019 at a single center. All surgeries were performed by a group of four high-volume fellowship-trained arthroplasty surgeons. All patients received at least 1 acetabular cup screw and RSA markers inserted into the acetabulum and proximal femur. Follow-up time points were 6 weeks, 6, 12 and 24 months and included patient reported outcome measures (HOOS, Oxford-12, Harris Hip Score, SF-36 and Satisfaction) as well as RSA assessment.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_21 | Pages 96 - 96
1 Dec 2016
Rooks K Hansen H Norton J Dzus A Allen L Hedden D
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The evolution of operative technology has allowed correction of complex spinal deformities. Neurological deficits following spinal instrumentation is a devastating complication and the risk is especially high in those with complex sagittal and coronal plane deformities. Prior to intraoperative evoked potential monitoring, spinal cord function was tested using the Stagnara Wake up test, typically performed after instrumentation once the desired correction has been achieved. This test is limited as it does not reflect the timeframe in which the problem occurred and it may be dangerous to some patients. Intraoperative neuromonitoring allows timely feedback of the effect of instrumentation and curve correction on the spinal cord. Pedicle screws that are malpositioned can result in poor fixation or neuronal injury. Evoked EMG monitoring can aid in accurate placement. A positive EMG response can alert the surgeon to a potential pedicle breech and allow them to reassess the placement of their hardware intraoperatively. The stimulation threshold is affected by the amount of surrounding bone acting as an insulator to electrical conduction and is variable in different regions of the spine. In the non-deformed, lumbar spine stimulation thresholds have been established. Such guidelines have not been well-developed for the thoracic spine, or for severely scoliotic spines. Thus our primary objective was to compare the stimulation threshold of the apical pedicle on the concave side to the stimulation threshold of the pedicles at the upper and lower instrumented levels.

Intraoperative EMG stimulation thresholds were done at 192 apical pedicles on the concave side of the deformity and then compared to those thresholds found at 169 terminal level pedicles. Only pedicles for which a stimulation threshold was found were reported and excluded those where a breech was suspected. The lowest stimulation required for an EMG response was documented to a maximum stimulation of 20 mA.

The mean threshold at the apex was 16.62 milliamps (mA) compared to 18.25mA at the terminal levels. This was compared with the t-test and showed a statistically significant difference (p<0.05).

In this study we report only the thresholds for the concave side, the pedicle that is most likely to be reduced in size. The threshold for stimulation is reduced compared to those seen at the highest and lowest instrumented level. Most of the apexes are located in the mid-thoracic spine with the highest instrumented levels being in the high thoracic spine and the lowest levels being in the lumbar spine. This study provides preliminary evidence that the apical, concave pedicle has a lower threshold than the end pedicles and one cannot rely on established thresholds from different areas of the spine. The surgeon should be cognisant of these differences when instrumenting at the apical level. Ongoing work is examining the convex apex threshold as well as the relationship between the effect of age and a diagnosis other than adolescent idiopathic scoliosis.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXVII | Pages 264 - 264
1 Sep 2012
Malhi A Bohm E Hedden D Burnell C Turgeon T
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Introduction

The purpose of this study was to compare the clinical outcomes and complications following bilateral simultaneous total knee arthroplasty in high body mass index (BMI) patients(>30kg/m2) to those of patients with a BMI<30 kg/m2.

Materials and Methods

Using data from an academic arthroplasty database and review of clinic charts we obtained health related quality of life (SF-12), and disease specific functional outcome scores (WOMAC or Oxford Knee Score). We also assessed length of hospital stay, ASA grade and transfusion requirements. Sixty six patients had a BMI<30 and 151 patients had a BMI>30.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 554 - 554
1 Nov 2011
Turgeon TR Bohm E Kesler N Petrak M Burnell C Hedden D
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Purpose: The purpose of this study is to measure in vivo linear head penetration of a newer generation highly crosslinked liner (X3, Stryker Orthopedics) using Radiostereometric Analysis (RSA).

Method: The 12 hips (11 patients) included in this study are a subset from a larger randomized controlled trial comparing Exeter stem migration in cement mantles with and without Tobramycin. Criteria for inclusion in this subset were the use of an uncemented Trident acetabular component containing X3 polyethylene in combination with a 32 mm stainless steel femoral head. The average age was 72.7 years (range 65 to 80), and there was an equal gender distribution. RSA examinations were taken with patients lying supine at six weeks, six months, one year, and two years postoperatively. The six week examinations were used as the reference examinations for measuring head penetration. Radiographic measurements and analyses were performed with the UmRSA software suite version 6.0 (RSA Biomedical, Umea, Sweden). Head penetration was determined via edge-detection measurements of the femoral head and acetabular cup.

Results: The mean cumulative femoral head penetration at 6 months was 0.23 mm; this remained statistically unchanged both at 1 year: 0.20mm (p=0.69, 95% UCL of the difference: +0.15mm) and 2 years: 0.25mm (p=0.77, 95% UCL of the difference: +0.10mm).

Conclusion: It is generally recognized that femoral head penetration of more than 0.1 mm per year can result in osteolysis. The purpose of cross linking polyethylene is to reduce wear to below this level. The results of this study show that after an initial bedding in of approximately 0.2 mm, femoral head penetration is not detectable over the subsequent 18 months. Further follow-up is underway to confirm that this promising reduction in wear is maintained.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 553 - 553
1 Nov 2011
Turgeon TR Bohm E Kesler N Petrak M Burnell C Hedden D
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Purpose: The purpose of this study is to determine if the addition of Tobramycin antibiotic powder to cement for primary hip replacement surgery increases the risk of long term aseptic loosening. This was accomplished by measurement of implant micromotion with Radiostereometric Analysis (RSA).

Method: Exeter femoral stems and Trident acetabular components were implanted into 33 patients. Stems were cemented in a randomized manner with either Simplex P or Simplex T. Tantalum beads were injected into the femur to serve as reference points for RSA measurements. RSA examinations were taken with supine positioning at six weeks, six months, one year, and two years post-operatively. Radiographic measurements and analyses were performed with the UmRSA software suite version 6.0 (RSA Biomedical, Umea, Sweden). Distal migration of the stem centroid was measured at each follow-up period and the mean migration rates for both groups were determined. Non-inferiority testing of stem migration in Simplex T compared to Simplex P was accomplished using a one sided t-test, with the significance level set at 0.05. A clinically inferior additional amount of distal migration was set at 0.4mm/yr.

Results: Eleven patients were excluded from the study: seven patients either dropped out of the study or missed the six week and/or two year follow-up examinations, two patients had radiographic image quality issues, and two patients had loosening of their tantalum markers in subsequent follow-ups. Of the remaining 22 patients, eight were male and 14 were female, with an average age at time of surgery of 71.2 (range, 63–81) years. The mean total distal migrations for the Tobramycin and non-Tobramycin cement groups at two years were 0.891 and 0.732 mm, respectively; the mean stem migration rates were 0.263 and 0.179 mm/yr, respectively. The differences in total distal migration and stem migration rate were not statistically significant (P = 0.06 and UCL = 0.173, respectively).

Conclusion: The addition of Tobramycin to Simplex cement does not appear to impact the distal migration pattern for a polished tapered cemented hip stem at two years. This finding suggests that Tobramycin does not have any clinically relevant deleterious effects on the in vivo mechanical properties of Simplex cement.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_IV | Pages 591 - 591
1 Nov 2011
Wadey VM Dev P Buckley R Hedden D
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Purpose: The RCPSC Orthopaedic Specialty Committee for Residency Training and the Examination Committee for Orthopaedic Surgery requested that work be completed to assist with identifying competencies that should be included in a core curriculum for graduating orthopaedic surgery residents in Canada. The purpose of this study was to determine competencies to be of greatest importance by orthopaedic surgeons whose primary affiliation was non-university, for the purpose of developing a core curriculum in orthopaedic surgery for graduating residents within Canada.

Method: A 281-item list of competencies was developed consisting of three sections: a previously validated curriculum for musculoskeletal health, Orthopaedic Specialty objectives of the Royal College of Physicians and Surgeons of Canada, curricula representing orthopaedic programs from accredited academic orthopaedic programs within Canada and, a comprehensive procedure list. Competencies were compared to existing curricula within Canada. A content review was completed and a modified questionnaire was developed. A stratified, randomized selection of, non – university, orthopaedic surgeons rated each individual item on an integer scale 1 to 4 of increasing level of importance. Summary statistics across all respondents were given. Average mean scores and standard deviations were computed. Secondary analyses were computed in general, paediatrics, trauma and adult reconstruction.

Results: 131/156 (84 %) of orthopaedic surgeons participated. 240/281 competencies (85.4%) were rated average scores of at least 3.0 suggesting probably important or important to demonstrate competency by completion of training. 41/281 items (15.6%) were given average scores between 2.0 and 2.93 thus suggesting not important.

Conclusion: This study identified competencies necessary for a Core Curriculum for Orthopaedic Surgery. Complex procedures in various categories and content considered less essential for orthopaedic surgeons were rated to be less important. How curriculum is ultimately structured, delivered and implemented needs to be studied. We know that learning activities are “driven” by the evaluation of competencies. Is competency-based education on the horizon or should we be focused on assessing competencies within the current method of curriculum delivery?


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 12 | Pages 1618 - 1622
1 Dec 2009
Wadey VMR Dev P Buckley R Walker D Hedden D

We have developed a list of 281 competencies deemed to be of importance in the training of orthopaedic surgeons. A stratified, randomised selection of non-university orthopaedic surgeons rated each individual item on a scale 1 to 4 of increasing importance. Summary statistics across all respondents were given. The mean scores and sds were computed. Secondary analyses were computed in general orthopaedics, paediatrics, trauma and adult reconstruction. Of the 156 orthopaedic surgeons approached 131 (84%) responded to the questionnaire. They rated 240 of the 281 items greater than 3.0 suggesting that competence in these was necessary by completion of training.

Complex procedures were rated to be less important. The structure, delivery and implementation of the curriculum needs further study. Learning activities are ‘driven’ by the evaluation of competencies and thus competency-based learning may soon be in the forefront of training programmes.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 225 - 225
1 May 2009
Mahood J Hedden D Hill D Lou E Moreau M Raso J
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To determine the pattern of brace wear compliance over time in both day and night time wear by using objective force measurements within the brace.

Twenty subjects who were diagnosed of AIS, age between nine and fifteen years, and new to brace treatment were recruited in this study. To use the data for analysis, only subjects who used the brace for five hours continuously either in daytime or nighttime were considered. For daytime wear, the selected five hour intervals had to begin with an initial spike in force after a period of non-activity as recorded by the transducer, which would indicate that they had just put on the brace. At night, the measurements began at one am and ended at six am.

Among the twenty subjects, only nine subjects’ data were used for daytime and eleven subjects’ data were used in nighttime. The average wear period was 11.4 ± 4.3 days for the day group, 11.6 ± 3.9 days for the night group. There was a statistically significant decrease in force within the first five hours of consecutive brace wear during daytime hours. The decrease was from 1.4 ± 0.6 (140% of prescribed force) in the first hour to 1.0 ± 0.6 in the fifth hour, a difference of 0.4, which is a 29% drop from the initial force. Most of the drop in force happened between hour one and hour two, as the difference in those two hours is 0.2 ± 0.1 (p = 0.001); between hours two and five the difference did not reach statistical significance. The observed difference between hours one and five for the night group was 0.2 ± 0.2, p = 0.06, which did not reach significance as well. Daytime forces in a Boston Brace tend to decrease over a period of time, but the nighttime forces seem to be maintained at the same level. These results show that daily adjustment of the brace tightness may be required to maintain the tightness level and the efficiency of brace treatment.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 344 - 345
1 May 2009
Moreau M Lou E Hill D Raso V Donauer A Hood J Hedden D Hill D Raso V Donauer A Hood J Hedden D
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The efficiency of brace treatment for adolescent idiopathic scoliosis is correlated to how the brace has been worn. A smart orthosis was developed to maintain the interface pressure between the brace and the body within the prescribed range during daily activity. Six patients with scoliosis, with Cobb angles of 31 +/− 5 degrees, who were new brace candidates were recruited. They used the system for four weeks: two weeks with monitoring only and two weeks with an automatic feedback activated. The time that the pressure level was in target level range during the study period was increased from 53 +/− 9% to 68 +/− 14% with the feedback activated. This work helps brace candidates wear their braces more effectively and receive the most benefit from the brace treatment. As a result, all subjects who participated in the study maintained their Cobb angles within + two degrees during the study period.

Brace correction based upon mechanical action requires appropriate interface pressure between the body and the brace. A smart orthosis was developed to record how much time (quantity) a brace was worn, how well (quality) it was used and how well the interface pressure was maintained to the prescribed level. Six subjects were recruited and they all were fitted with Boston style braces. Each subject wore the brace for 2 weeks without the force maintenance system activated to serve as the control period, and the remaining 2 weeks with the force maintenance system activated. During the automatic feedback mode, the pressure maintenance system was activated only during the daytime hours (8:00–22:00hrs) to avoid disturbing the patients during sleep. The subject could either return the system to us after 1 month or continue to use the system until the next clinic.

The time that the pressure level was in the target level range during the study period was increased from 53 +/− 9% to 68 +/− 14% with the feedback activated. The average brace wear time for the study period was 72 +/− 15% (12.6hr/day) of the prescribed time (17.5 +/− 3.8 hours). The curve severity of all subjects on the following clinical visit was the same (within measurement error) as the first visit (32 +/− 5 vs 31 +/− 5 degrees). Compliance was not affected when wearing the monitor.

The smart orthosis was able to improve the efficiency of a conventional brace by maintaining the prescribed interface pressure automatically. This project helps brace candidates wear their braces more effectively and gets the most benefit from the brace treatment. As a result, all participating subjects maintained their Cobb angle within +/− 2 degrees during the study period.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_II | Pages 248 - 248
1 May 2009
Hiscox C Bohm E Burnell C Hedden D
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Image guided navigation systems for total knee replacement surgery (TKR) are gaining popularity in an effort to improve both alignment and functional outcome. This trial was undertaken to compare one year functional outcome and radiological alignment of TKRs inserted with and without an image guided navigation system.

Patients were randomised to undergo surgery using either an image guided navigation system or traditional instrumentation. Pre and post-operative Knee Society (KSS), WOMAC and SF-36 scores were collected. Postoperatively, limb and implant alignment & rotation were assessed using both full-length films and CT scans.

One hundred and twenty-three patients (one hundred and forty-five knees) were enrolled: eighty-one females, forty-two males, mean age sixty-seven years. Age, gender and pre-operative range of motion, KSS WOMAC and SF-36 scores did not differ between the groups. While there was no statistically significant difference in postoperative KSS, WOMAC and seven of eight SF-36 subscales, the navigated group demonstrated better post-operative SF-36 General Health Scores. Mean postoperative flexion in all patients was 115°, and did not differ between groups. Mean post-operative leg alignment demonstrated more varus in the navigated group (2.1°) versus the non-navigated group (0.9°, p=0.02), however there was a trend towards a smaller standard deviation in the navigated group. Rotational alignment of the femoral component relative to the femur, tibial component relative to the tibia, and tibial component relative to the femoral component were not statistically different between groups; however, there were larger standard deviations of these measures in the non-navigated group. Pre-operative alignment appeared to affect tibial component placement; varus knees had a mean of 3° of tibial component internal rotation while valgus knees had a mean of 12° external rotation.

Imaged guided navigation systems appear to reduce the variability in TKR component placement and limb alignment. However, this may not necessarily translate into better mean limb alignment or early functional outcome.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 76 - 76
1 Mar 2008
Lai K Bohm E Burnell C Hedden D
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A retrospective case-control study was performed to examine modifiable medical co-morbidities in patients who develop deep infection after primary total hip or knee replacement. To reduce bias, matching was undertaken using age, gender, and procedure. Co-morbidities were classified by system: cardiovascular, respiratory, gastrointestinal, genitourinary, metabolic, haematological and neurological. Initial analyses demonstrate that patients with infected primary hip or knee replacements are more likely to suffer from medical conditions than patients who did not develop infections. Since many of these co-morbidities are preventable or treatable, early screening and intervention may play a role in reducing prosthetic joint infection.

Deep infection of total hip (THA) and knee replacements (TKA) causes significant patient morbidity and requires considerable health care resources to treat. In order to identify preventable or modifiable medical conditions associated with prosthetic joint infection, a retrospective case-control study was undertaken.

Fifty patients who developed a culture proven deep infection after primary THA or TKA were studied. To reduce bias, a control group of arthroplasty patients was selected using one to one matching based on age, gender, and procedure. Co-morbidities in each group were recorded, and classified by system.

Analysis revealed that patients with joint infections are more likely to suffer from an increased number of co-morbidities than the matched control group. The odds ratios and 95% confidence intervals were determined as: cardiovascular 2.3 (1.0–5.0), respiratory 2.3 (0.8–6.7), gastrointestinal 0.8 (0.4–1.9), genitourinary 3.1 (1.1–8.9), metabolic 1.8 (0.7–4.9), haematological 2.9 (1.1–7.8), neurological 2.9 (0.8–9.9) and diabetes 4.0 (1.2–13.4). The case group had a higher mean BMI than the control group: 33.7 versus 30.9, p=0.00.

Since many of the co-morbidities associated with infection are preventable or readily treatable, early screening and intervention may play a role in reducing the burden of prosthetic joint infection.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 80 - 80
1 Mar 2008
Lai K Bohm E Burnell C Hedden D
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A retrospective case-control study was performed to examine modifiable medical co-morbidities in patients who develop deep infection after primary total hip or knee replacement. To reduce bias, matching was undertaken using age, gender, and procedure. Co-morbidities were classified by system: cardiovascular, respiratory, gastrointestinal, genitourinary, metabolic, haematological and neurological. Initial analyses demonstrate that patients with infected primary hip or knee replacements are more likely to suffer from medical conditions than patients who did not develop infections. Since many of these co-morbidities are preventable or treatable, early screening and intervention may play a role in reducing prosthetic joint infection.

Deep infection of total hip (THA) and knee replacements (TKA) causes significant patient morbidity and requires considerable health care resources to treat. In order to identify preventable or modifiable medical conditions associated with prosthetic joint infection, a retrospective case-control study was undertaken.

Fifty patients who developed a culture proven deep infection after primary THA or TKA were studied. To reduce bias, a control group of arthroplasty patients was selected using one to one matching based on age, gender, and procedure. Co-morbidities in each group were recorded, and classified by system.

Analysis revealed that patients with joint infections are more likely to suffer from an increased number of co-morbidities than the matched control group. The odds ratios and 95% confidence intervals were determined as: cardiovascular 2.3 (1.0 – 5.0), respiratory 2.3 (0.8 – 6.7), gastrointestinal 0.8 (0.4–1.9), genitourinary 3.1 (1.1–8.9), metabolic 1.8 (0.7 – 4.9), haematological 2.9 (1.1–7.8), neurological 2.9 (0.8–9.9) and diabetes 4.0 (1.2–13.4). The case group had a higher mean BMI than the control group: 33.7 versus 30.9, p=0.00.

Since many of the co-morbidities associated with infection are preventable or readily treatable, early screening and intervention may play a role in reducing the burden of prosthetic joint infection.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 81 - 81
1 Mar 2008
Narayanan U Wright J Hedden D Alman B Howard A Slater M Donaldson S
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Little is known about the priorities of patients undergoing surgery for idiopathic scoliosis. This study explores the priorities of adolescents and contrasts them from their parents and their surgeons. Fifty-five pairs of children and parents underwent structured interviews separately, to explore their concerns, desires and expectations both about scoliosis and surgery. Surgeons of these patients and from across Canada completed a similar questionnaire. We found a significant mismatch between child, parent and surgeon priorities. This mismatch has implications on matters relating to decision making, informed consent, understanding of patient satisfaction, and measuring outcomes that are meaningful to patients.

To define the concerns, desires (goals) and expectations of adolescents undergoing surgery for idiopathic scoliosis and to contrast them from their parents and surgeons.

We conducted structured interviews of fifty-five pairs of adolescents and parents separately. The questionnaire had sections on concerns, desires and expectations regarding both scoliosis and surgery, with items pertaining to present and future effects on appearance, pain, physical and psychosocial function and health. Parents also reported what their child’s responses might be. Their surgeons (four) and paediatric spine surgeons (twenty-four) across Canada completed the same questionnaire. Analysis involved repeated measures ANOVA, intra-class correlation coefficients and kappa statistics.

Parents were more concerned than their children about present and future consequences of scoliosis. Surgeons were least concerned. Children, parents and surgeons agreed that improving physical appearance was the primary goal of surgery. Surgeons agreed very little about the natural history of scoliosis, other goals of surgery and the likelihood of specific outcomes. Parents wanted more from surgery than their children. Parents and patients had greater expectations of surgery than surgeons. Adolescents had different priorities from their parents, but parents were aware of this difference and knew what their child’s priorities were.

Adolescents with idiopathic scoliosis, their parents and surgeons have different priorities. This mismatch might stem from uncertainty about the natural history of idiopathic scoliosis for individual patients.

Knowledge of patient priorities is vital for shared decision making, informed consent, understanding patient satisfaction, and for measuring outcomes that matter most to patients.

Funding:

Orthopaedic Research & Education Foundation: (Unni. G. Narayanan: AAOS/OREF Health Services research Fellowship award)

Canadian Institutes of Health Research: (James G. Wright, Douglas M. Hedden, Benjamin Alman, Andrew Howard, Sandra Donaldson)

DePuyAcroMed-Johnson & Johnson Medical Products (James G. Wright, Douglas M. Hedden, Benjamin Alman, Andrew Howard, Sandra Donaldson)

Synthes, Canada (James G. Wright, Douglas M. Hedden, Benjamin Alman, Andrew Howard, Sandra Donaldson)


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 59 - 60
1 Mar 2008
Sekundiak T Hedden D
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Revision of massive femoral defects in revision hip arthroplasty is extremely difficult. This study assesses defects where bone loss extends to the isthmus of the femur. By using a medial allogeneic femoral graft in a wedge fashion, rotational and axial stability of the femoral implant is augmented, allowing bone ingrowth to occur. The technique is described which is simple, inexpensive and readily available in most institutions.

A medial allogeneic femoral strut graft is assessed in hip arthroplasty revision to improve implant stability and thereby promote bony ingrowth into the implant.

Thirty-three revision arthroplasties were preformed in twenty-nine patients (avg. age 63.7 yrs) using a fully-porous coated implant of eight or ten inch length. All patients had a Paprosky Type III or IV femoral defect. The implants, by definition were press-fit at or past the isthmus. To aid ingrowth and to decrease axial and rotational stresses, a medial femoral strut graft was wedged into the remaining medial host bone and under the collar of the implant. Cabling was utilized to prevent dislodgement of the graft from the implant and host. A radiographic and clinical comparison to a series of similar defects without grafting was performed for a minimum of thirty-five month follow-up.

Twenty-eight of the thirty-three implants had radiographic evidence of ingrowth with migration of only two millimeters (average). Medial femoral strut grafting displayed much better potential for ingrowth and decreased potential for migration. Harris hip scores averaged eighty-one from a preoperative score of thirty-two. Cost of the grafts averaged $2100 cheaper compared to a bulk structural graft which would otherwise have been used in this situation.

Medial femoral strut grafts augment initial implant stability to allow for implant in- growth. The advantages of the medial strut grafts are decreased cost, improved stability, and improved implant in- growth potential.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 142 - 142
1 Mar 2008
Donaldson S Howard A Hedden D Stephens D Alman B Wright J
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Purpose: To assess the change in disease-specific quality of life associated with operating on patients with AIS, compared to non operative patients.

Methods: The Climent Quality of Life for Spinal Deformities Scale (QLPSD)was administered prospectively to 119 patients undergoing scoliosis surgery and 42 patients followed for bracing or observation. Change in quality of life after two years (adjusted for baseline quality of life) was used to estimate the short term benefit of scoliosis surgery. Bracing status was also analyzed at baseline as a covariate to determine its effect on improvement in quality of life.

Results: The operated group experienced an increase in quality of life of 4.3 points (95% C.I. 0.69, 7.88) on the 105 point Climent scale. Although statistically significant, this increase was lower than the 5.5 point cutoff we had defined a priori as clinically significant. Among the operative patients, there was no difference in the quality of life score between those braced at baseline (91.2) and those not (90.5) (p=0.73). In non operative patients, those braced had a baseline quality of life score of 88.2, and those not braced 83.3, this difference was also not significant (p=0.13).

Conclusions: Scoliosis surgery results in a small increase, of questionable clinical significance, in spine-related quality of life at two years.

Funding : Commerical funding

Funding Parties : This trial was funded by (in alphabetical order) Canadian Institutes of Health Research, DePuyAcroMed-Johnson & Johnson Medical Products, and Synthes, Canada.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 82 - 83
1 Mar 2008
Donaldson S Hedden D Stephens D Alman B Howard A Wright J
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Five surgeons independently rated clinical photographs of forty patients with AIS. Ratings of shoulder blades, shoulder symmetry, and waist symmetry were related to “overall appearance”, and were also correlated with rib prominence and Cobb angle. Because the components of surgeons’ ratings of appearance differed, this may lead to inconsistent recommendations regarding surgery.

To identify patient characteristics associated with surgeons’ ratings of patient physical deformity in Adolescent Idiopathic Scoliosis (AIS).

Five surgeons independently rated clinical photographs of forty patients with AIS. Surgeons separately rated the appearance of patients’ shoulder blades, shoulder symmetry, waist symmetry and also rated their “overall appearance [in five categories from zero (best) to five (worst)]. The following clinical and radiographic data was also collected: rib prominence, vertebral rotation, shoulder height, spinal imbalance, Cobb angle, age, sex, and body mass index.

Surgeons’ mean rating for “overall appearance” was moderately correlated with rib prominence (r = 0.48), vertebral rotation (r = 0.44) and Cobb angle (r = 0.53). Surgeons’ rating of patients’ “overall appearance” was affected by each of: shoulder blades (p = 0.001), shoulder symmetry (p = 0.01) and waist symmetry (p = 0.001). However, each surgeon weighted components of patients’ appearance differently to arrive at their overall rating of appearance (p< 0.006).

Because patients’ physical appearance is an important element of surgical decision making, differences among surgeons could be contributing to inconsistent recommendations.

Surgeons’ ratings of physical appearance are based on surgeons’ ratings of patients’ shoulder blades, waist symmetry and shoulder symmetry but surgeons weight those elements differently.

Surgeon decision making is complicated. It is based on radiographs and subjective assessment. Patients’ appearance undoubtedly influences surgeon recommendation for surgery. We need to clarify surgeons’ ratings and improve the criteria for surgeon decision making.

Funding: This trial was funded by (in alphabetical order) The Canadian Institutes of Health Research, DePuyAcroMed-Johnson & Johnson Medical Products, and Synthes, Canada.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 295 - 296
1 Sep 2005
Narayanan U Wright J Hedden D Alman B Howard A Feldman B Krahn M Llewellyn-Thomas H Slater M Donaldson S
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Introduction and Aims: Little is known about the priorities of patients undergoing surgery for idiopathic scoliosis. Surgery, a major undertaking, is recommended to correct or prevent worsening deformity, and to avoid uncertain future consequences. This study aims to define the concerns, desires (goals) and expectations of adolescents undergoing surgery for idiopathic scoliosis.

Method: We conducted structured interviews of 55 pairs of adolescents, who had spinal fusion, and their parents separately. The questionnaire included sections on concerns, desires and expectations regarding both scoliosis and surgery, with items about present and future effects on appearance, pain, physical and psychosocial function and health. Parents reported both their priorities and what their child’s responses might be. Patients’ surgeons (four) completed the same questionnaire. Paediatric spine surgeons across Canada (24) were also surveyed. Surgeons were asked to respond as if their child was a patient. Analysis involved repeated measures ANOVA, intra-class correlation coefficients and kappa statistics.

Results: Parents were significantly more concerned than their children about present and future consequences of scoliosis and of spine fusion surgery. Surgeons were the least concerned about the consequences of scoliosis, even when asked to respond as if their child was the patient. Children, their parents and surgeons did agree that improving physical appearance was the primary goal of surgery. However, surgeons agreed very little among themselves about the natural history of scoliosis, other goals of surgery and about the likelihood of specific outcomes. Consequently, with the exception of improving physical appearance, surgeons’ goals and expectations of surgery were significantly different from those of either the patients or parents. Parents consistently wanted and expected more from surgery than their children. Parents and patients had greater expectations of surgery than surgeons. Although adolescents had different priorities from their parents, parents were aware of these differences and reliably predicted what their children’s priorities were.

Conclusion: Idiopathic scoliosis patients, their parents, and surgeons have different priorities. Surgeons’ opinions about the natural history of scoliosis and treatment goals are discordant. These findings have important implications on shared decision-making and informed consent, and might contribute to better understanding and measurement of outcomes that matter to patients, including satisfaction.