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Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 74 - 74
1 Aug 2020
Mistry M Feibel R Salimian A Malcolm JC
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Dysglycemia in the post-operative period has been associated with increased rates of infection following total joint arthroplasty. Additionally, patients without clinical diagnosis of diabetes with hemoglobin A1c% values between 5.7% and 6.4% have been shown to be dysglycemic in the peri-operative period. This study examines the influence of post-operative blood glucose management on rates of re-operation for infection in patients undergoing total joint arthroplasty in diabetic, and clinically non-diabetic patients.

We performed a retrospective review of prospectively collected data, for all primary, elective total hip and total knee arthroplasties performed at The Ottawa Hospital between April 2010 and October 2017. Kaplan-Meier survivorship, and mutivarient regression analysis were used to determine predictors of infection based on pre-operative diabetes status, HbA1c%, and post-operative insulin management.

4159 joints met inclusion criteria. Patients with HbA1c 5.7–6.4% had lower rate of revision for infection if they received post-operative blood glucose management (0.80%), vs without glucose management (1.20%). Kaplan-Meier survivorship analysis showed this difference to be insignificant (p=0.23). Patients with DM1 had statistically worse survivorship when compared to other groups (p=0.010).

Patients with undiagnosed perioperative dysglycemia may be at a greater predisposition for developing infection, requiring re-operation, following total joint arthroplasty. This study may be underpowered due to overall low rates of revision. More rigorous peri-operative glucose management strategies may be required for patients, who otherwise receive no glycemic management outside of hospital. This is more pertinent with trends towards decreasing post-operative lengths-of-stay.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 25 - 25
1 Aug 2020
Salimian A Howatt J Dervin G Kim P
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The Oxford mobile bearing knee prosthesis (Zimmer Biomet Inc, Warsaw, Ind) is considered a good treatment option for isolated medial compartment knee arthrosis. From February 2001 until August 2016, 1719 primary Oxford medial unicompartmental knee replacement procedures were completed at our center by a group of seven surgeons. We undertook this study to examine the long-term survivorship of the Oxford unicompartmental knee replacement looking at survivorship and reasons for failure.

A retrospective consecutive case series review was completed, and all revisions and re-operations were identified. Conversion to total knee replacement (TKA) was considered a failure. Kaplan-Meier survival analysis was used to calculate the 15-year survivorship of the group overall. We specifically looked at age, gender, BMI and surgeon caseload in addition to the reasons for failure. A statistical analysis was performed and differences in survivorship were compared for the variables listed. A logistic cox regression was performed to explore predictors of revision.

Overall 15-year survivorship was 89.9%. Female survivorship of 88.1% was statistically worse than the male group at 91.8% (p=0.018). Younger patients (75yrs of age (p= 0.036). There was a large range in surgical case load by individual surgeons (range 17–570 knees). There were no statistically significant differences in age, BMI, or gender when comparing the individual surgeon groups. There was a large range in 15-year survivorship between individual surgeons (range 78.3% – 95%). Overall the most common reason for revision was due to wear of the unreplaced portion of the knee (lateral and/or patella-femoral joint) followed by aseptic loosening, polyethylene dislocation, infection or persistent pain.

The 15-year survivorship results of the Oxford medial unicompartmental knee replacement at our center compares favourably to other published series and large registry data series. We found a reduction in survivorship in female patients and younger patients (< 5 5yrs). There were also significant differences in survivorship based on the individual surgeon. A more selective patient approach yielded the best long-term survivorship and equivalent to that of total knee replacement. We therefore suggest using a more selective approach when choosing patients for a medial unicompartmental knee replacement with the Oxford mobile bearing prosthesis in order to enhance long-term survivorship.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 9 - 9
1 Aug 2020
Papp S Thomas S Harris N Salimian A Gartke K
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The clinical guidelines for hip fracture management indicate that indwelling foley catheterization should be avoided when possible. Alternatives to indwelling catheters such as intermittent or condom catheters are recommended. Appropriate catheterization usage is important in hip fracture patients to avoid complications such as urinary tract infections (UTIs) (7–24% of patients) or post-operative urinary retention (POUR) (20–56% of patients). In this study, we aim to, (1) evaluate catheter usage in hip fracture patients at a large tertiary care centre, (2) compare current practices in catheter usage to clinical guidelines, (3) determine the incidence of POUR in hip fracture patients (4) determine the factors that increase one's risk of developing POUR.

We analyzed 584 hip fracture patients between the ages of 18 and 102 admitted between November 2015 and October 2017 at a tertiary Care Hospital. Data collected included patient demographics, fracture pattern, surgical procedure, length of stay, co-morbidities and catheter use. We compared actual catheter usage to suggested guidelines to determine whether recommendations were being followed. We also investigated the incidence of POUR and risk factors associated with developing POUR. Independent samples t-test were used to compare continuous dependent variables in bivariate analyses and a logistic regression was used to determine predictors of developing POUR, catheter usage, and length of stay in multivariate analyses. T

Over three quarters (76.9%) of patients with hip fractures were treated with a catheter during their admission, 63.5% of which were inserted pre-operatively and 36.5% of which were inserted post-operatively. Indwelling catheters accounted for 92.2% of catheters used, while intermittent and catheter condoms accounted for 7.8%. POUR occurred in 98 of 584 cases (16.7%). Age (p = 0.004), gender (p=0.001), and presence of kidney disease (p=0.033) were statistically significant predictors of POUR. Fracture pattern (p=0.825), surgical procedure (p=0.298), diabetes mellitus (p=0.309) and UTI in the past 60 days (p=0.848) or on admission (p=0.999) were not statistically significant predictors of developing POUR. The development of POUR did not significantly increase length of stay (p=0.558). There was no statistically significant correlation between developing POUR and extended post-operative catheter use over 24 hours (p=0.844) or 48 hours (p=0.862). Patients who received a catheter pre-operatively or post-operatively for longer than 24 hours were not significantly more likely to develop POUR (p=0.057).

Catheter use was common for all hip fracture patients and indwelling catheters were used in the overwhelming majority of cases. The high frequency of catheter usage, and specifically indwelling catheter usage, suggests that there is low compliance with the clinical guidelines for hip fracture patients. The incidence of POUR was 17%. Older, male patients were more likely to develop POUR. Although not statistically significant, more appropriate catheter use may decrease urinary complications such as POUR.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 24 - 24
1 Aug 2020
Salimian A Slullitel P Grammatopoulos G Kreviazuk C Beaulé P Wilkinson JM
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The use of cementless acetabular components is currently the gold standard for treatment in total hip arthroplasty (THA). Porous coated cups have a low modulus of elasticity that enhances press-fit and a surface that promotes osseointegration. Monoblock acetabular cups represent a subtype of uncemented cup with the liner moulded into the metal shell, minimizing potential backside wear and eliminating the chance of mal-seating. The aim of this study was to compare the short-term clinical and radiographic performances of a modular cup with that of a monoblock cup, with particular interest in the advent of lucent lines and their correlation with clinical outcomes.

In this multi-surgeon, prospective, randomized, controlled trial, 86 patients undergoing unilateral THA were recruited. Participants were randomized to either a porous-coated, modular metal-on-polyethylene (MoP) acetabular component (n=46) or a hydroxyapatite (HA)- and titanium-coated monoblock shell with ceramic-on-ceramic (CoC) bearing (n=42). The porous-coated cup had an average pore size of 250 microns with an average volume porosity of 45%, whereas the monoblock shell had an average pore size of 300 microns with an average volume porosity of 48% and a HA coating thickness of 80 nm. There were no baseline demographic differences between both groups regarding sex, age, body mass index (BMI), or American Society of Anaesthesia (ASA) class (p>0.05). All of the sockets were under-reamed by 1 mm. Radiographs and patient-reported outcome measures (PROMs), including modified Harris Hip Score (mHHS), Western Ontario and McMaster Universities Arthritis Index (WOMAC) and University of California at Los Angeles (UCLA) Hip Score, were available for evaluation at a minimum of 2 years of follow-up. A radiolucent distance between the cup and acetabulum of ≥0.5 mm was defined as gap if it was diagnosed from outset or as radiolucency if it had sclerotic edges and was found on progressive x-ray analyses.

Thirty-two gaps (69%) were found in the modular cup group and 28 (6%) in the monoblock one (p=0.001). Of the former, 17 filled the gaps whereas 15 turned into a radiolucency at final assessment. Of the latter, only 1 of the gaps turned into a radiolucency at final follow-up (p 0.05) in both groups. Only the porous-coated cup was an independent predictor of lucent lines (OR:0.052, p=0.007). No case underwent revision surgery due to acetabular loosening during the study period. Only 2 cases of squeaking were reported in the CoC monoblock shell.

Both porous-coated modular and hydroxyapatite-coated monoblock cups showed successful clinical results at short-term follow-up, however, the former evidenced a significantly higher rate of radiolucent line occurrence, without any association with PROMs. Since these lines indicate the possibility of future cup loosening, longer follow-up and assessment are necessary.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 25 - 25
1 Jul 2020
Galmiche R Beaulé P Salimian A Carli A
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Recently, new metallurgical techniques allowed the creation of 3D metal matrices for cementless acetabular components. Among several different products now available on the market, the Biofoam Dynasty cup (MicroPort Orthopedics® Inc., Arlington, TN, USA) uses an ultraporous Titanium technology but has never been assessed in literature. Coping with this lack of information, our study aims to assess its radiological osteointegration at two years in a primary total hip arthroplasty and compares it to a successful contemporary cementless acetabular cup.

This monocentric retrospective study includes 96 Dynasty Biofoam acetabular components implanted between March 2010 and August 2014 with a minimum 2 years radiographic follow-up. Previous acetabular surgery, any septic issue or re-operation for component malposition were exclusion criteria. They were compared to 96 THA using the Trident PSL matched for age, gender, BMI and follow-up. Presence of radiolucencies and sclerotic lines were described on AP pelvis views using the classification of DeLee and Charnley

There was no statistical difference between the two groups concerning demographics and mean follow-up (p> 0.05). Shell's anteversion was similar but inclination was greater in the biofoam group (p=0.006). 27,17% of the Biofoam shells presented radiolucencies in 2 zones or more and 0% of the Trident shells. 11,96% of Biofoam cups showed radiolucencies in the 3 zones of DeLee comparing to 0% of the Trident cups. There was no statistical difference between the Biofoam group (n=54/96) and the Trident PSL group (n=57/96) in pre-operative functional scores for both WOMAC subscales and SF-12. When evaluating last follow-up PROM's, no significant differences were found comparing the entirety of both groups, 56 Biofoam and 51 Trident PSL. No difference was found either when comparing Biofoam patients with ³ 2 zones of radiolucencies (n=15) to the whole Trident group (n=51).

This study raises concerns about radiologic evidence of osteointegration of the Biofoam acetabular cup. Nevertheless, these radiological findings do not find any clinical correlation considering clinical scores. Thus, it may question the real meaning of these high-rated radiolucencies, which at first sight reflect a poorer osteointegration. The first possible limitation with this study is an overinterpretation of the radiographs. Nevertheless, both observers were blinded regarding the patients groups and clinical outcomes and there was a strong inter-observer reliability. Although both cohorts were matched on their demographics and were similar on the cup anteversion, we noticed a slightly lower abduction angle in the Biofoam population. It could reduce the bone-implant coverage area and hence hinders the bony integration, but this difference was small and both groups remained in the Lewinneck security zone. Furthermore, even if patients were matched on age, gender, BMI and follow-up, other variables can influence early osteointegration (smoke status, osteoporosis) and have not been controlled even though we have no reasons to think their distribution could differ in the 2 groups.

The real clinical meaning of these findings remains unknown but serious concerns are raised about the radiographic osteointegration of the Dynasty Biofoam acetabular components. Concerns are all the more lawful that this implants aim to enhance osteointegration.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 94 - 94
1 Jul 2020
Undurraga S Au K Salimian A Gammon B
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Longstanding un-united scaphoid fractures or scapholunate insufficiency can progress to degenerative wrist osteoarthritis (termed scaphoid non-union advanced collapse (SNAC) or scapho-lunate advanced collapse (SLAC) respectively). Scaphoid excision and partial wrist fusion is a well-established procedure for the surgical treatment of this condition. In this study we present a novel technique and mid-term results, where fusion is reserved for the luno-capitate and triquetro-hamate joints, commonly referred to as bicolumnar fusion. The purpose of this study was to report functional and radiological outcomes in a series of patients who underwent this surgical technique.

This was a prospective study of 23 consecutive patients (25 wrists) who underwent a bicolumnar carpal fusion from January 2014 to January 2017 due to a stage 2 or 3 SNAC/SLAC wrist, with a minimum follow-up of one year. In all cases two retrograde cannulated headless compression screws were used for inter-carpal fixation. The clinical assessment consisted of range of motion, grip and pinch strength that were compared with the unaffected contralateral side where possible. Patient-reported outcome measures, including the DASH and PRWE scores were analysed. The radiographic assessment parameters consisted of fusion state and the appearance of the radio-lunate joint space. We also examined the relationship between the capito-lunate fusion angle and wrist range of motion, comparing wrists fused with a capito-lunate angle greater than 20° of extension with wrists fused in a neutral position.

The average follow-up was 2.9 years. The mean wrist extension was 41°, flexion 36° and radial-ulnar deviation arc was 43° (70%, 52% and 63% of contralateral side respectively). Grip strength was 40 kg and pinch strength was 8.9 kg, both 93% of contralateral side. Residual pain for activities of daily living was 1.4 (VAS). The mean DASH and PRWE scores were 19±16 and 29±18 respectively. There were three cases of non-union (fusion rate of 88%). Two wrists were converted to total wrist arthroplasty and one partial fusion was revised and healed successfully. Patients with an extended capito-lunate fusion angle trended toward more wrist extension but this did not reach statistical significance (P= 0.07). Wrist flexion did not differ between groups. Radio-lunate joint space narrowing progressed in 2 patients but did not affect their functional outcome.

After bicolumnar carpal fusion using retrograde headless screws, patients in this series maintained a functional flexion-extension arc of motion, with grip-pinch strength that was close to normal. These functional outcomes and fusion rates were comparable with standard 4-corner fusion technique. A capito-lunate fusion angle greater than 20° may provide more wrist extension but further investigation is required to establish this effect. This technique has the advantage that compression screws are placed in a retrograde fashion, which does not violate the proximal articular surface of the lunate, preserving the residual load-bearing articulation. Moreover, the hardware is completely contained, with no revision surgery for hardware removal required in this series.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 102 - 102
1 Jul 2020
Castano D Grammatopoulos G Salimian A Beaulé P
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During a periacetabular osteotomy (PAO), intra-operative assessment of correction of acetabular parameters is typically performed using fluoroscopy of the hip, a technique that has not been shown to produce predictable measurements. Furthermore, paralysing agents are used in order to facilitate dissection and fragment mobilization. The effect of paralysing agents on spino-pelvic posture is yet to be investigated.

This study aims to: 1. Compare the reliability of intra-operative x-rays versus hip fluoroscopy in the assessment of acetabular fragment correction and 2. Evaluate the effect of changes in spino-pelvic alignment on the assessment of acetabular correction. An IRB approved, retrospective review of all patients who underwent a PAO at our institution between 2006–2018 was performed. Patient demographic data was collected and all available imaging studies were retrieved. Patients were excluded if there was no available to review intra-operative AP pelvis x-ray or intra-operative fluoroscopic PA image of the hip.

Using a validated hip analysis software (Hip2Norm), the lateral center edge angle (LCEA) and acetabular index (AI) of plain radiographs were measured. The sacro-femoral-pubic angle (SFP), along with the LCEA and AI of the fluoroscopic image were measured using ImageJ. A oneway ANOVA was used to detect differences between measured parameters in the intra-operative x-ray, the post-operative x-ray and the fluoroscopic image. A total of 93 patients were identified. 26 patients were excluded due to missing data. The mean LCEA in the post-operative, intra-operative, and fluoroscopic groups were as follows: 33.67° (range 5.3° to 52.4°), 30.71°(range 9° to 55.6°), and 29.23°(range 12.4° to 51.4°) respectively. The mean AI in the post-operative, intra-operative, and fluoroscopic groups were as follows: −0.65° (range −18.10° to 27.30°), 0.35°(range −16.10° to 17.20°), and 5.54°(range −11.66° to 27.83°) respectively.

When comparing intra-operative to post-operative plain radiographs, there was no statistically significant difference in AI (ΔAI −1±1.29° p=0.71) or LCEA (ΔLCEA 2.95±1.38° p=0.09). When comparing fluoroscopy to post-operative plain radiographs, there was a statistically significant difference in AI (ΔAI −6.21±1.29° p < 0 .0001) as well as LCEA (ΔLCEA 4.44±1.38° p < 0 .0001). Statistical analysis revealed no influence of demographics (age, BMI, gender), on acetabular correction parameters. The mean SPF angles measured from intra-operative and post-operative x-rays were 69.32±5.11° and 70.45±5.52°. There was a statistically significant difference between these 2 measurements with a ΔSFP of 1.03° (p < 0 .0001).

The results of our study show that the use of intra-operative x-ray for the assessment of LCEA and AI is more reliable than fluoroscopic images. Further, we found a difference in SFP angle, which offers an indirect assessment of pelvic tilt, between the intra-operative and the post-operative plain x-rays. This suggests that there are changes in pelvic tilt during the surgery, which can be attributed to either patient positioning or changes in spino-pelvic posture secondary to the paralysing agents used by the anesthetists. The use of intra-operative x-rays as well as the effect of paralysing agents on spino-pelvic alignment should be considered by surgeons performing PAO's.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 24 - 24
1 Jul 2020
Galmiche R Poitras S Salimian A Kim P Feibel R Gofton W Abdelbary H Beaulé P
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The effectiveness of total hip replacement as a surgical intervention has revolutionized the care of degenerative conditions of the hip joint. However, the surgeon is still left with important decisions in regards to how best deliver that care with choice of surgical approach being one of them especially in regards to the short-term clinical outcome. It is however unclear if a particular surgical approach offers a long-term advantage. This study aims to determine the influence of the three main surgical approaches to the hip on patient reported outcomes and quality of life after 5 years post-surgery.

We extracted from our prospective database all the patients who underwent a Total Hip Replacement surgery for osteoarthritis or osteonecrosis between 2008 and 2012 by an anterior, posterior or lateral approach. All the pre-operative and post-operative HOOS (Hip disability and Osteoarthritis Outcome Score) and WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) scores were noted. Analysis of covariance (ANCOVAs) were used to study the relationship between amount of change in HOOS and WOMAC subscales (dependant variables) and approach used, by also including confounding factors of age, gender, ASA (American Society of Anaesthesiologists) score, Charnley score and Body Mass Index. A total of 1895 patients underwent a primary total hip arthroplasty during the considered period. Among them, 367 had pre-operative and ≥5 years post operative PROM scores (19.47%)

The mean follow-up for the study cohort was 5.3 years (range 5 to 7 years) with, 277 at 5 years, 63 at 6 years, and 27 at 7 years. In the posterior approach group we had 138 patients (37.60%), 104 in the lateral approach (28.34%) and 125 in the anterior approach (34.06%). There were no significant differences between the 3 groups concerning the Charnley classification, BMI, Gender, ASA score, side and pre-operative functional scores. We did not observe any significant difference in the amount of change in HOOS and WOMAC subscales between the 3 groups. There were no differences either in the post-operative scores in ultimate value.

Our monocentric observational study shows that these three approaches provide predictable and comparable outcomes on HRQL and PROMs at long-term follow-up both in terms of final outcome but also in percent improvement. This study has several limitations. We excluded patients who underwent revision surgery leaving the unanswered question of how choice of surgical approach could lead to different revision rates, which have an impact on the functional outcomes. Moreover, even if we controlled for the most important confounders by a multivariate analysis model, there is still some involved cofounders, which could potentially lead to a bias such as smoking, socio-economical status or femoral head diameter. But we do not have any reason to think that these parameters could be unequally distributed between the three groups. Finally, our study cohort represents of 19.47% of the complete cohort. The fact that not all patients have PROM's was pre-determined as eight years ago we instituted that only 1 in 5 patients that returned their pre-operative questionnaire would get their PROM's at follow-up. Despite this, our statistical power was sufficient.